/* OrbitLab learning-portal layout: navbar, sidebar, hero, cards, topic detail,
   simulations. Loaded after theme.css and explore.css (reuses .viz, .search-*,
   .audio, .term-tip from explore.css). */

body[data-page] { background: var(--app-bg); }

/* ---------------- offline banner (Req 10.6) ---------------- */
/* Persistent indicator shown while the connection is lost. portal.js toggles
   the [hidden] attribute on the online/offline events. */
.offline-banner {
  position: fixed; inset-inline: 0; bottom: 0; z-index: 60;
  display: flex; align-items: center; justify-content: center; gap: 10px;
  padding: 10px 16px;
  font-size: 13.5px; font-weight: 600;
  color: #04121a;
  background: #ffc55c;
  border-top: 1px solid color-mix(in srgb, #ffc55c 70%, #000);
  box-shadow: 0 -4px 16px rgba(0, 0, 0, 0.28);
}
.offline-banner[hidden] { display: none; }
.offline-banner-dot {
  width: 9px; height: 9px; border-radius: 50%;
  background: #b45309; flex-shrink: 0;
}

/* ---------------- navbar ---------------- */
.navbar {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; gap: 16px;
  padding: 10px 22px; border-bottom: 1px solid var(--border);
  background: var(--app-bg);
  background: color-mix(in srgb, var(--app-bg) 88%, transparent);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}
.nav-brand { display: flex; align-items: center; gap: 9px; text-decoration: none; color: var(--text); font-size: 16px; }
.nav-brand .logo { display: inline-flex; }
.nav-brand-text b { color: var(--accent); font-weight: 700; }
.nav-links { display: flex; gap: 4px; margin-left: 10px; flex: 1; }
.nav-links a {
  color: var(--muted); text-decoration: none; font-size: 13.5px; font-weight: 500;
  padding: 7px 11px; border-radius: 8px;
}
.nav-links a:hover { color: var(--text); background: var(--panel); }
.nav-links a.active { color: var(--text); background: var(--panel); box-shadow: inset 0 -2px 0 var(--accent); }
.nav-actions { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; font-size: 15px; cursor: pointer;
  background: var(--panel-2); border: 1px solid var(--border); border-radius: 9px; color: var(--text);
}
.icon-btn:hover { border-color: var(--accent); }
.nav-sim { color: var(--accent); text-decoration: none; font-size: 13px; font-weight: 600; white-space: nowrap; padding: 0 4px; }
.nav-toggle { display: none; flex-direction: column; gap: 4px; width: 38px; height: 36px; background: var(--panel-2); border: 1px solid var(--border); border-radius: 9px; cursor: pointer; align-items: center; justify-content: center; }
.nav-toggle span { display: block; width: 16px; height: 2px; background: var(--text); border-radius: 2px; }

/* ---------------- shell + sidebar ---------------- */
.portal-shell { display: flex; max-width: 1340px; margin: 0 auto; }
.portal-sidebar {
  width: 236px; flex-shrink: 0; align-self: flex-start;
  /* Desktop sticky sidebar offset is derived from the rendered navbar height
     (H5/AC 5.3): portal.js measures .navbar and writes its px height to the
     --nav-h custom property, so the sidebar stays aligned when the navbar wraps
     on narrow-but-wide viewports. The 57px fallback keeps it correct before JS
     runs (and if the navbar is absent). */
  position: sticky; top: var(--nav-h, 57px); max-height: calc(100vh - var(--nav-h, 57px)); overflow-y: auto;
  padding: 22px 10px 40px; border-right: 1px solid var(--border);
}
.portal-sidebar .side-grp { font-size: 11px; text-transform: uppercase; letter-spacing: 1px; color: var(--accent-2); font-weight: 600; margin: 16px 0 5px 12px; }
.portal-sidebar ul { list-style: none; margin: 0; padding: 0; }
.portal-sidebar a {
  display: block; padding: 6px 12px; margin: 1px 0; border-radius: 7px;
  color: var(--muted); text-decoration: none; font-size: 13.5px; border-inline-start: 2px solid transparent;
}
.portal-sidebar a:hover { color: var(--text); background: var(--panel); }
.portal-sidebar a.active { color: var(--text); border-inline-start-color: var(--accent); background: var(--panel); }

.portal-main { flex: 1; min-width: 0; max-width: 1020px; padding: 26px 34px 70px; }
.portal-footer { border-top: 1px solid var(--rule); padding: 22px 34px; color: var(--muted); font-size: 13px; text-align: center; }
.portal-footer p { max-width: 820px; margin: 0 auto; }

/* ---------------- breadcrumbs + sections ---------------- */
.crumbs { font-size: 13px; color: var(--muted); margin: 0 0 18px; display: flex; gap: 8px; align-items: center; }
.crumbs a { color: var(--accent); text-decoration: none; }
.crumbs a:hover { text-decoration: underline; }

.section-title { font-size: 22px; margin: 38px 0 6px; }
.section-sub { color: var(--muted); font-size: 14.5px; margin: 0 0 18px; max-width: 720px; }
.eyebrow { font-size: 12px; text-transform: uppercase; letter-spacing: 2px; color: var(--accent); margin: 0 0 8px; font-weight: 600; }

/* ---------------- hero ---------------- */
.hero { margin-bottom: 14px; }
.hero h1 { font-size: clamp(26px, 4vw, 38px); line-height: 1.12; margin: 0 0 12px; }
.hero .lead { font-size: 17px; color: var(--text-soft); max-width: 640px; margin: 0 0 18px; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-dashboard {
  padding: 40px 34px; border-radius: 18px; border: 1px solid var(--border);
  /* Opaque fallback first: below-baseline browsers ignore the color-mix()
     background below and keep this solid gradient so the hero tint renders (C7). */
  background: linear-gradient(160deg, var(--panel), var(--app-bg));
  background:
    radial-gradient(700px 300px at 85% -20%, color-mix(in srgb, var(--accent) 22%, transparent), transparent 70%),
    linear-gradient(160deg, var(--panel), var(--app-bg));
  margin-bottom: 34px;
}
.hero-topic { display: grid; grid-template-columns: 1fr; gap: 22px; padding: 8px 0 18px; }
.hero-topic .eyebrow { color: var(--c, var(--accent)); }
.hero-sim .viz { aspect-ratio: 16 / 9; }

/* ---------------- dashboard grids ---------------- */
.domain-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 16px; }
.domain-card {
  display: block; padding: 20px; border-radius: 14px; text-decoration: none;
  background: var(--panel); border: 1px solid var(--border);
  border-top: 3px solid var(--c, var(--accent));
  transition: transform 0.15s ease, border-color 0.15s ease;
}
.domain-card:hover { transform: translateY(-3px); border-color: var(--c, var(--accent)); }
.domain-icon { font-size: 30px; display: block; margin-bottom: 8px; }
.domain-card h3 { margin: 0 0 6px; font-size: 17px; color: var(--text); }
.domain-card p { margin: 0; font-size: 13.5px; color: var(--muted); }

/* learning paths */
.paths-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 16px; }
.path-card { padding: 18px; border-radius: 14px; background: var(--panel); border: 1px solid var(--border); border-inline-start: 4px solid var(--c, var(--accent)); }
.path-card h3 { margin: 0 0 4px; font-size: 16px; display: flex; align-items: center; gap: 8px; }
.path-card p { margin: 0 0 12px; font-size: 13px; color: var(--muted); }
.path-steps { list-style: none; margin: 0; padding: 0; }
.path-steps li { margin: 0; }
.path-steps a { display: flex; align-items: center; gap: 8px; padding: 6px 8px; border-radius: 7px; color: var(--text-soft); text-decoration: none; font-size: 13.5px; }
.path-steps a:hover { background: var(--panel-2); color: var(--text); }
.path-steps .step-dot { width: 18px; height: 18px; flex-shrink: 0; border-radius: 50%; border: 2px solid var(--c, var(--accent)); display: inline-flex; align-items: center; justify-content: center; font-size: 10px; color: var(--c, var(--accent)); }
.path-steps .step-dot .svg-icon { width: 12px; height: 12px; }
.path-steps a.done .step-dot { background: var(--c, var(--accent)); color: #04121a; }
.path-progress { height: 6px; border-radius: 3px; background: var(--panel-2); overflow: hidden; margin-bottom: 12px; }
.path-progress > span { display: block; height: 100%; background: var(--grad-accent); border-radius: 3px; transition: width 0.9s var(--ease-out); }

/* continue widget */
.continue { margin: 30px 0; }
.continue-body { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 14px; }

/* ---------------- link-card grid (planets / dwarfs) ---------------- */
.link-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 14px; }
.link-card {
  display: flex; align-items: center; gap: 12px; padding: 14px; border-radius: 13px;
  text-decoration: none; background: var(--panel); border: 1px solid var(--border);
  transition: transform 0.15s ease, border-color 0.15s ease;
}
.link-card:hover { transform: translateY(-2px); border-color: var(--accent-2); }
.link-card .planet-dot { width: 34px; height: 34px; }
.link-card .lc-title { font-size: 15px; font-weight: 600; color: var(--text); }
.link-card .lc-sub { font-size: 12px; color: var(--muted); }

/* ---------------- progress stats + achievements (dashboard) ---------------- */
.stats-panel { margin: 24px 0 30px; padding: 18px 20px; background: var(--panel); border: 1px solid var(--border); border-radius: 14px; }
.stats-tiles { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 14px; }
.stat-tile { flex: 1; min-width: 110px; text-align: center; background: var(--panel-2); border-radius: 11px; padding: 12px 10px; }
.stat-num { display: block; font-size: 28px; font-weight: 700; color: var(--accent); line-height: 1.1; }
.stat-label { font-size: 12px; color: var(--muted); }
.stat-sub { display: block; margin-top: 3px; font-size: 11px; font-weight: 600; color: var(--accent-2); letter-spacing: 0.3px; }
.badges-block { margin-top: 4px; }
.badges-summary { margin: 0 0 8px; font-size: 12px; color: var(--muted); }
.badges-row { display: flex; flex-wrap: wrap; gap: 8px; }
.badge-chip {
  display: inline-flex; align-items: center; gap: 6px; font-size: 12.5px;
  padding: 5px 11px; border-radius: 999px; border: 1px solid var(--border);
  background: var(--panel-2); color: var(--muted); opacity: 0.55; filter: grayscale(1);
}
.badge-chip.got { opacity: 1; filter: none; color: var(--text); border-color: var(--accent); background: var(--panel-2); background: color-mix(in srgb, var(--accent) 14%, var(--panel-2)); }

/* assessment scores list (Req 9.4) */
.assess-scores { margin-top: 16px; }
.assess-title { font-size: 13px; font-weight: 700; margin: 0 0 8px; color: var(--text); }
.assess-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 6px; }
.assess-item {
  display: flex; align-items: center; gap: 10px; padding: 7px 11px;
  background: var(--panel-2); border: 1px solid var(--border); border-radius: 9px; font-size: 12.5px;
}
.assess-item .assess-id { flex: 1; color: var(--text); text-transform: capitalize; }
.assess-item .assess-score { color: var(--muted); font-variant-numeric: tabular-nums; }
.assess-item .assess-pct { font-weight: 700; color: var(--muted); font-variant-numeric: tabular-nums; min-width: 44px; text-align: end; }
.assess-item.passed { border-color: var(--accent); }
.assess-item.passed .assess-pct { color: var(--accent); }

/* ---------------- learning-path cards (extra states) ---------------- */
.path-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 10px; }
.path-level {
  flex-shrink: 0; font-size: 10.5px; text-transform: uppercase; letter-spacing: 0.6px;
  padding: 3px 8px; border-radius: 999px; background: var(--panel-2); color: var(--accent-2); border: 1px solid var(--border);
}
.path-card.complete { border-color: var(--c, var(--accent)); box-shadow: 0 0 0 1px var(--c, var(--accent)); }
.path-done { font-size: 13px; font-weight: 600; color: var(--c, var(--accent)); margin: 0 0 10px; }
.path-steps a.locked { opacity: 0.55; }
.path-steps a.locked .step-dot { border-color: var(--muted); color: var(--muted); }

/* ---------------- "Your guide" panel (Req 14.1/14.2/14.5/14.6) ---------------- */
/* A deterministic guidance card above the module grid: a progress summary, the
   next-best lesson CTA, "revisit" chips for failed-quiz lessons, and a learner-
   confirmed reading-band suggestion. Uses the brass/gold history accent. */
.guide-panel {
  margin: 0 0 22px; padding: 16px 18px; border-radius: 14px;
  border: 1px solid var(--border);
  border-inline-start: 3px solid var(--history-accent, #c9a227);
  background: color-mix(in srgb, var(--history-accent, #c9a227) 8%, var(--panel));
}
.guide-title {
  display: flex; align-items: center; gap: 8px; margin: 0 0 6px;
  font-size: 15px; color: var(--history-accent-line, #e6c25a);
}
.guide-title svg { width: 18px; height: 18px; }
.guide-summary { margin: 0 0 12px; font-size: 13.5px; color: var(--text-soft); }
.guide-next {
  display: inline-flex; flex-direction: column; align-items: flex-start; gap: 2px;
  color: var(--history-accent-ink, #1b1200); background: var(--history-accent, #c9a227);
  border: 1px solid transparent; text-decoration: none;
}
.guide-next-label { font-weight: 700; font-size: 14px; }
.guide-next-lesson { font-size: 12px; opacity: 0.85; }
.guide-done { display: flex; align-items: center; gap: 8px; margin: 0; font-size: 13.5px; color: var(--good); }
.guide-done svg { width: 16px; height: 16px; }
.guide-gaps { margin-top: 14px; }
.guide-gaps-label { display: block; font-size: 11.5px; color: var(--muted); margin-bottom: 6px; }
.revisit-chips { display: flex; flex-wrap: wrap; gap: 6px; }
.revisit-chip {
  display: inline-flex; align-items: center; gap: 5px; font-size: 12px;
  padding: 4px 10px; border-radius: 999px; border: 1px solid var(--border);
  background: var(--panel-2); color: var(--text-soft); text-decoration: none;
}
.revisit-chip svg { width: 13px; height: 13px; flex-shrink: 0; }
.revisit-chip:hover { border-color: var(--history-accent, #c9a227); }
.guide-band {
  margin-top: 14px; padding-top: 12px; border-top: 1px solid var(--rule);
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 10px;
}
.guide-band-msg { margin: 0; font-size: 13px; color: var(--text-soft); }
.guide-band-actions { display: flex; gap: 8px; }
.guide-band-actions .btn { font-size: 13px; padding: 7px 12px; }

/* ---------------- history course hub: module cards ---------------- */
/* The 10-module grid on /history. Cards mirror the .path-card idiom (panel +
   border + brass/gold inline-start accent) so the hub reads as a designed grid,
   not raw links. The whole card is a single link. */
.module-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px;
}
.module-card {
  border-radius: 14px; background: var(--panel); border: 1px solid var(--border);
  border-inline-start: 4px solid var(--c, var(--history-accent, #c9a227));
  transition: transform var(--t-fast) var(--ease-out), box-shadow var(--t-med) var(--ease-out),
              border-color var(--t-med) ease;
}
.module-card:hover { transform: translateY(-2px); box-shadow: 0 8px 26px var(--shadow); }
.module-card-link {
  display: block; padding: 16px 18px; color: inherit; text-decoration: none; height: 100%;
}
.module-card-head { display: flex; align-items: flex-start; gap: 12px; }
.module-ordinal {
  flex-shrink: 0; width: 34px; height: 34px; border-radius: 10px;
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 800; font-variant-numeric: tabular-nums;
  color: var(--history-accent-ink, #1b1200); background: var(--c, var(--history-accent, #c9a227));
}
.module-card-titles { flex: 1; min-width: 0; }
.module-card-titles h3 { margin: 0 0 6px; font-size: 16px; color: var(--text); line-height: 1.3; }
.module-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.module-count { font-size: 12px; color: var(--muted); }
.module-desc { margin: 12px 0 0; font-size: 13px; color: var(--text-soft); line-height: 1.55; }
.module-done { display: flex; align-items: center; gap: 6px; margin: 12px 0 0; font-size: 13px; font-weight: 600; color: var(--good); }
.module-done svg { width: 15px; height: 15px; }
/* Completion ring (shared .ring primitive), tinted to the module accent. */
.module-card .module-ring { flex-shrink: 0; }
.module-card .module-ring .ring-track { stroke: color-mix(in srgb, var(--c, var(--history-accent, #c9a227)) 20%, var(--panel-2)); }
.module-card .module-ring .ring-fill { stroke: var(--c, var(--history-accent, #c9a227)); }
.module-card .module-ring .ring-label { font-size: 12px; color: var(--history-accent-line, #e6c25a); }
.module-card.complete { border-color: var(--c, var(--history-accent, #c9a227)); box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--c, var(--history-accent, #c9a227)) 40%, transparent); }
.module-card.complete .module-ring .ring-fill { stroke: var(--good); }
.module-card.complete .module-ring .ring-label { color: var(--good); }
/* Difficulty chip (levelChip() emits .module-level). */
.module-level {
  flex-shrink: 0; font-size: 10.5px; text-transform: uppercase; letter-spacing: 0.6px;
  padding: 3px 8px; border-radius: 999px; background: var(--panel-2); color: var(--history-accent-line, #e6c25a);
  border: 1px solid var(--border);
}

/* ---------------- history course hub: soft-locked modules (A.3.1) ---------------- */
/* A locked module card is greyed but still navigable (soft lock): the link stays
   active so direct lesson URLs keep working. */
.module-card.locked { opacity: 0.72; }
.module-card.locked .module-card-link { filter: grayscale(0.4); }
.module-lock {
  display: inline-flex; align-items: center; gap: 5px; font-size: 11px; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.5px; color: var(--muted);
  padding: 2px 8px; border-radius: 999px; border: 1px solid var(--border); background: var(--panel-2);
}
.module-lock svg { width: 13px; height: 13px; }
.module-prereqs { margin: 10px 0 2px; }
.module-prereqs-label { display: block; font-size: 11.5px; color: var(--muted); margin-bottom: 6px; }
.prereq-chips { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 6px; }
.prereq-chip {
  display: inline-flex; align-items: center; gap: 5px; font-size: 12px;
  padding: 4px 10px; border-radius: 999px; border: 1px solid var(--border);
  background: var(--panel-2); color: var(--muted);
}
.prereq-chip svg { width: 13px; height: 13px; flex-shrink: 0; }

/* ---------------- history lesson soft-lock notice (Req 2.6 / A.3.1) ---------------- */
.lesson-lock-notice {
  display: flex; align-items: flex-start; gap: 12px; margin: 0 0 20px;
  padding: 13px 15px; border-radius: 12px; border: 1px solid var(--border);
  background: color-mix(in srgb, var(--accent) 8%, var(--panel));
  border-inline-start: 3px solid var(--accent);
}
.lesson-lock-icon { flex-shrink: 0; color: var(--accent); margin-top: 2px; }
.lesson-lock-icon svg { width: 20px; height: 20px; }
.lesson-lock-body { flex: 1; min-width: 0; }
.lesson-lock-body strong { display: block; font-size: 14.5px; color: var(--text); margin-bottom: 3px; }
.lesson-lock-body p { margin: 0; font-size: 13px; color: var(--muted); }
.lesson-lock-dismiss {
  flex-shrink: 0; display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px; padding: 0; border-radius: 8px; cursor: pointer;
  background: transparent; border: 1px solid transparent; color: var(--muted);
}
.lesson-lock-dismiss:hover { background: var(--panel-2); color: var(--text); }
.lesson-lock-dismiss svg { width: 16px; height: 16px; }

/* ---------------- observatory hotspot panorama (design A.3.4, Req 5.4/12.1) ---------------- */
/* A layered illustrated panorama with keyboard-tabbable dot buttons; each opens
   a caption card. The stage is position:relative so hotspots place by --x/--y
   (percentages of the image box). Interaction is progressive: the artwork and
   dots render without JS; course.js wires open/close. */
.observatory-panorama { margin: 0; }
.panorama-hint { margin: 0 0 10px; font-size: 13px; color: var(--muted); }
.panorama-stage {
  position: relative;
  border-radius: 14px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--panel-2);
  line-height: 0;
}
.panorama-img { display: block; width: 100%; height: auto; }
/* Themed fallback tile when the illustration is missing, so the stage is never
   empty and hotspots still have a surface to sit on. */
.panorama-img--fallback {
  aspect-ratio: 16 / 9;
  height: auto;
  background:
    radial-gradient(120% 120% at 50% 10%, color-mix(in srgb, var(--c, #c9a227) 45%, transparent), transparent 60%),
    linear-gradient(160deg, var(--panel-2), var(--panel));
}

/* A hotspot: a wrapper absolutely positioned at (--x, --y); the dot is centred
   on that point and its caption card floats above it. */
.hotspot {
  position: absolute;
  left: var(--x, 50%);
  top: var(--y, 50%);
  transform: translate(-50%, -50%);
  line-height: normal;
}
.hotspot-dot {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; padding: 0;
  border-radius: 999px; cursor: pointer;
  color: var(--history-accent-ink, #1b1200); background: var(--history-accent, #c9a227);
  border: 2px solid #fff8e6;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.35);
  font-size: 14px; font-weight: 700;
  transition: transform 0.12s ease, box-shadow 0.12s ease;
}
.hotspot-dot:hover { transform: scale(1.12); }
/* Visible focus indicator on keyboard focus (Req 12.4/12.7). */
.hotspot-dot:focus-visible {
  outline: 3px solid var(--focus, #7c9cff);
  outline-offset: 2px;
}
.hotspot-num { pointer-events: none; }
.hotspot.is-open .hotspot-dot {
  transform: scale(1.12);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--history-accent, #c9a227) 45%, transparent);
}

/* The caption card: hidden until its dot is activated (native [hidden]). It sits
   above the dot and is width-constrained so long captions wrap. */
.hotspot-card {
  position: absolute;
  left: 50%;
  bottom: calc(100% + 10px);
  transform: translateX(-50%);
  width: max-content;
  max-width: min(260px, 70vw);
  z-index: 3;
  padding: 11px 13px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--panel);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  text-align: start;
}
.hotspot-card[hidden] { display: none; }
.hotspot-card-title { margin: 0 0 4px; font-size: 13.5px; font-weight: 700; color: var(--text); }
.hotspot-card-caption { margin: 0; font-size: 12.5px; line-height: 1.5; color: var(--muted); }
.panorama-credit { margin: 8px 2px 0; font-size: 11.5px; color: var(--muted); line-height: 1.4; }

/* Respect reduced motion: no dot scale/transition animations. */
@media (prefers-reduced-motion: reduce) {
  .hotspot-dot { transition: none; }
  .hotspot-dot:hover, .hotspot.is-open .hotspot-dot { transform: translate(0, 0); }
}

/* ---------------- quiz ("Check yourself") ---------------- */
.quiz-section { border-inline-start: 3px solid var(--accent); }
.quiz-intro { font-size: 13.5px; color: var(--muted); margin: 0 0 14px; }
.quiz-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 18px; }
.quiz-prompt { font-size: 15px; font-weight: 600; margin: 0 0 9px; }
.quiz-choices { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 8px; }
.quiz-choice {
  text-align: left; font-family: inherit; font-size: 14px; cursor: pointer;
  background: var(--panel-2); color: var(--text); border: 1px solid var(--border);
  border-radius: 9px; padding: 10px 13px; transition: border-color 0.12s ease, background 0.12s ease;
}
.quiz-choice:hover:not(:disabled) { border-color: var(--accent); }
.quiz-choice:disabled { cursor: default; }
.quiz-choice.correct { border-color: #5cf2a0; background: rgba(92, 242, 160, 0.16); color: #d6ffe8; }
.quiz-choice.incorrect { border-color: #ff6b6b; background: rgba(255, 107, 107, 0.16); color: #ffd9d9; }
.quiz-explain { font-size: 13.5px; margin: 9px 0 0; padding: 9px 12px; border-radius: 8px; background: var(--panel-2); color: var(--text-soft); }
.quiz-explain.ok { border-left: 3px solid #5cf2a0; }
.quiz-explain.no { border-left: 3px solid #ff6b6b; }
.quiz-result { margin-top: 16px; padding: 12px 16px; border-radius: 10px; background: var(--panel-2); display: flex; align-items: center; gap: 12px; flex-wrap: wrap; font-size: 14.5px; }
.quiz-result.passed { background: color-mix(in srgb, #5cf2a0 16%, var(--panel-2)); }
.quiz-result strong { font-size: 17px; color: var(--accent); }
.quiz-retry { margin-left: auto; padding: 7px 14px; }

/* ---------------- activities: order (timeline ordering) ---------------- */
/* Logical properties throughout; the list is vertical so move up/down is
   direction-agnostic and RTL-safe. */
.activity-section { border-inline-start: 3px solid var(--accent); }
.activity-prompt { font-size: 15px; font-weight: 600; margin: 0 0 6px; }
.activity-instr { font-size: 13px; color: var(--muted); margin: 0 0 14px; }
.order-list { list-style: none; margin: 0 0 14px; padding: 0; display: flex; flex-direction: column; gap: 8px; }
.order-chip {
  display: flex; align-items: center; gap: 10px;
  background: var(--panel-2); color: var(--text); border: 1px solid var(--border);
  border-radius: 10px; padding: 10px 12px; cursor: grab;
  transition: border-color 0.12s ease, background 0.12s ease, box-shadow 0.12s ease;
}
.order-chip:hover { border-color: var(--accent); }
.order-chip:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.order-chip.is-grabbed { border-color: var(--accent); box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 45%, transparent); background: color-mix(in srgb, var(--accent) 10%, var(--panel-2)); }
.order-chip.is-dragging { opacity: 0.6; cursor: grabbing; }
.order-chip.is-correct { border-color: #5cf2a0; background: rgba(92, 242, 160, 0.16); }
.order-chip.is-incorrect { border-color: #ff6b6b; background: rgba(255, 107, 107, 0.14); }
.order-chip-index { flex: 0 0 auto; min-width: 22px; height: 22px; display: inline-flex; align-items: center; justify-content: center; border-radius: 50%; background: var(--panel); border: 1px solid var(--border); font-size: 12px; font-weight: 700; color: var(--accent); }
.order-chip-label { flex: 1 1 auto; font-size: 14px; }
.order-chip-controls { flex: 0 0 auto; display: inline-flex; gap: 4px; }
.order-move {
  width: 30px; height: 30px; display: inline-flex; align-items: center; justify-content: center;
  font-family: inherit; font-size: 12px; cursor: pointer; color: var(--text);
  background: var(--panel); border: 1px solid var(--border); border-radius: 7px;
  transition: border-color 0.12s ease, background 0.12s ease;
}
.order-move:hover:not(:disabled) { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 8%, transparent); }
.order-move:disabled { opacity: 0.4; cursor: default; }
.order-move:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.activity-actions { display: flex; gap: 10px; flex-wrap: wrap; }
.activity-feedback { margin: 12px 0 0; padding: 9px 12px; border-radius: 8px; background: var(--panel-2); color: var(--text-soft); font-size: 13.5px; }
.activity-feedback.ok { border-inline-start: 3px solid #5cf2a0; }
.activity-feedback.no { border-inline-start: 3px solid #ff6b6b; }
/* Visually hidden live region (announcements for assistive tech only). */
.activity-live { position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap; border: 0; }

/* `match` (pair) activity - "Make the matches". Each row pairs a fixed prompt on
   the start side with a <select> of shuffled options; grading paints the row
   green/correct or red/incorrect with a ✓/✗ mark. Mirrors the .order-chip
   language (panel-2 rows, accent focus, semantic pass/fail colours). */
.match-list { list-style: none; margin: 0 0 14px; padding: 0; display: flex; flex-direction: column; gap: 8px; }
.match-row {
  display: grid; grid-template-columns: minmax(0, 1fr) auto minmax(0, 1.1fr) 20px;
  align-items: center; gap: 10px;
  padding: 9px 12px; border-radius: 10px; background: var(--panel-2); border: 1px solid var(--border);
  transition: border-color var(--t-med) ease, background var(--t-med) ease;
}
.match-left { font-size: 14px; font-weight: 600; color: var(--text); min-width: 0; }
.match-connector { color: var(--muted); display: inline-flex; align-items: center; }
.match-connector svg { width: 16px; height: 16px; }
.match-select {
  font-family: inherit; font-size: 14px; color: var(--text); background: var(--panel);
  border: 1px solid var(--border); border-radius: 8px; padding: 8px 10px; width: 100%; min-width: 0; cursor: pointer;
  transition: border-color var(--t-med) ease;
}
.match-select:hover { border-color: var(--accent); }
.match-select:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.match-select:disabled { opacity: 0.75; cursor: default; }
.match-mark { justify-self: center; font-weight: 800; font-size: 15px; line-height: 1; }
.match-row.is-correct { border-color: #5cf2a0; background: rgba(92, 242, 160, 0.14); }
.match-row.is-correct .match-mark { color: #5cf2a0; }
.match-row.is-incorrect { border-color: #ff6b6b; background: rgba(255, 107, 107, 0.12); }
.match-row.is-incorrect .match-mark { color: #ff6b6b; }
/* RTL: flip the decorative connector arrow so it points across the pair. */
[dir="rtl"] .match-connector svg { transform: scaleX(-1); }
/* Narrow screens: stack the prompt above its menu so long text never crowds. */
@media (max-width: 560px) {
  .match-row {
    grid-template-columns: minmax(0, 1fr) 20px;
    grid-template-areas: "left mark" "select select";
    row-gap: 8px;
  }
  .match-left { grid-area: left; }
  .match-mark { grid-area: mark; }
  .match-connector { display: none; }
  .match-select { grid-area: select; }
}

@media (prefers-reduced-motion: reduce) {
  .order-chip { transition: none; }
  .order-move { transition: none; }
  .match-row, .match-select { transition: none; }
}

/* ---------------- simulations catalog ---------------- */
.sims-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 18px; }
.sim-card { background: var(--panel); border: 1px solid var(--border); border-radius: 14px; overflow: hidden; display: flex; flex-direction: column; }
.sim-card .viz { aspect-ratio: 16 / 10; border: 0; border-bottom: 1px solid var(--border); border-radius: 0; }
.sim-card-body { padding: 14px 16px; }
.sim-card-body h3 { margin: 0 0 5px; font-size: 16px; display: flex; align-items: center; gap: 8px; }
.sim-card-body p { margin: 0 0 12px; font-size: 13.5px; color: var(--muted); }

/* ---------------- topic detail ---------------- */
.topic-hero { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 26px; align-items: center; margin-bottom: 8px; }
.topic-hero.no-visual { grid-template-columns: 1fr; }
.topic-visual img { width: 100%; border-radius: 14px; border: 1px solid var(--border); display: block; }
/* H4 (AC 4.5): when the hero <img> ships no intrinsic width/height attributes
   (heroDimAttrs emits the pair only when both are valid), reserve layout space
   with a default aspect ratio matching the fallback tile so the box does not
   collapse to zero height before the image loads, keeping CLS ≤ 0.1. Scoped to
   :not([width]) so images that DO carry intrinsic dimensions keep the
   browser-derived aspect ratio and are never distorted; object-fit: cover keeps
   the reserved box undistorted if the loaded image differs from 16 / 10. */
.topic-visual img:not([width]) { aspect-ratio: 16 / 10; object-fit: cover; }
.topic-visual .planet-orb {
  position: relative;
  width: 100%; aspect-ratio: 1 / 1; max-width: 320px; margin: 0 auto; border-radius: 50%;
  background: radial-gradient(circle at 32% 30%, #fff6, transparent 42%), var(--orb, #888);
  box-shadow: 0 0 60px -10px var(--orb, #888);
}
/* Stylised, illustrative flair for the worlds shown as orbs (no photo yet).
   Jupiter/Mars/Saturn render real photos, so they don't need orb styling. */
.planet-orb[data-body="earth"] {
  background: radial-gradient(circle at 30% 28%, #fff7, transparent 40%),
    radial-gradient(circle at 65% 70%, #5cf2a0aa, transparent 30%),
    radial-gradient(circle at 35% 62%, #6fe0aaaa, transparent 26%), var(--orb);
}
.planet-orb[data-body="venus"] {
  background: radial-gradient(circle at 32% 30%, #fff8, transparent 44%),
    repeating-radial-gradient(circle at 50% 50%, rgba(255, 240, 200, 0.10) 0 6%, transparent 6% 12%), var(--orb);
}
.planet-orb[data-body="mercury"] {
  background: radial-gradient(circle at 30% 28%, #fff5, transparent 40%),
    radial-gradient(circle at 60% 65%, rgba(0, 0, 0, 0.22), transparent 22%),
    radial-gradient(circle at 72% 38%, rgba(0, 0, 0, 0.16), transparent 14%), var(--orb);
}
.planet-orb[data-body="uranus"], .planet-orb[data-body="neptune"] {
  box-shadow: 0 0 72px -8px var(--orb);
}
.planet-orb[data-body="neptune"]::before {
  content: ""; position: absolute; inset: 0; border-radius: 50%;
  background: radial-gradient(circle at 58% 42%, rgba(0, 0, 0, 0.28), transparent 16%);
}
.topic-visual figcaption { font-size: 12px; color: var(--muted); margin-top: 8px; text-align: center; }
/* Gradient hero placeholder seeded by the record's colour, used for any type
   whose photo is missing or fails to load (galaxies, black holes, etc.). */
.topic-visual--fallback {
  width: 100%; aspect-ratio: 16 / 10; border-radius: 14px;
  border: 1px solid var(--border);
  background:
    radial-gradient(circle at 20% 22%, rgba(255, 255, 255, 0.22), transparent 36%),
    radial-gradient(circle at 80% 78%, rgba(0, 0, 0, 0.38), transparent 48%),
    radial-gradient(circle at 62% 30%, rgba(255, 255, 255, 0.10), transparent 28%),
    linear-gradient(135deg, var(--c, #7c9cff), #05070f);
  box-shadow: 0 0 60px -14px var(--c, #7c9cff);
}

.fact-pills { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0 0; }
.fact-pill { background: var(--panel); border: 1px solid var(--border); border-radius: 11px; padding: 8px 13px; }
.fact-pill dt { font-size: 10.5px; text-transform: uppercase; letter-spacing: 0.5px; color: var(--muted); }
.fact-pill dd { margin: 2px 0 0; font-size: 14px; font-weight: 600; color: var(--text); }

/* ---------------- reading-level toggle (Req 3) ---------------- */
/* The Reading_Level_Toggle is a segmented pill control in the topic hero
   offering exactly the three age bands; the active band is marked both by
   aria-pressed and this visual state (3.2, 3.8). */
.reading-level { display: flex; align-items: center; gap: 10px 14px; flex-wrap: wrap; margin: 18px 0 0; }
.reading-level-label {
  font-size: 11px; text-transform: uppercase; letter-spacing: 1px;
  color: var(--muted); font-weight: 600; white-space: nowrap;
}
.reading-level-options {
  display: inline-flex; gap: 3px; padding: 3px;
  background: var(--panel); border: 1px solid var(--border); border-radius: 999px;
}
.reading-level-btn {
  padding: 5px 14px; min-height: 30px;
  font: inherit; font-size: 13px; font-weight: 600; font-variant-numeric: tabular-nums;
  color: var(--muted); background: transparent;
  border: 1px solid transparent; border-radius: 999px; cursor: pointer;
  transition: color 0.15s ease, background-color 0.15s ease;
}
.reading-level-btn:hover { color: var(--text); background: var(--panel-2); }
.reading-level-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
.reading-level-btn.is-active,
.reading-level-btn[aria-pressed="true"] {
  color: var(--app-bg); background: var(--accent); border-color: var(--accent);
}
@media (pointer: coarse) {
  .reading-level-btn { min-height: 44px; padding-inline: 16px; }
}

.t-sections { display: grid; gap: 16px; margin-top: 30px; }
.t-section { background: var(--panel); border: 1px solid var(--border); border-radius: 14px; padding: 20px 22px; }
.t-section > h2 { margin: 0 0 10px; font-size: 18px; display: flex; align-items: center; gap: 9px; }
.t-section .sec-icon { font-size: 19px; }
.t-section p { margin: 0; color: var(--text-soft); font-size: 15px; line-height: 1.65; }
.t-tryit .viz { aspect-ratio: 16 / 9; margin-top: 14px; }
.t-tryit .tryit-instructions { margin-top: 12px !important; font-size: 13.5px; color: var(--muted); }

.dyk-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 12px; }
.dyk-card { background: var(--panel-2); border-radius: 11px; padding: 14px 16px; font-size: 14px; color: var(--text-soft); border-inline-start: 3px solid var(--accent); }

.related-chips { display: flex; flex-wrap: wrap; gap: 9px; }
.related-chips a {
  font-size: 13.5px; text-decoration: none; padding: 7px 14px; border-radius: 999px;
  background: var(--panel-2); color: var(--accent); border: 1px solid var(--border);
}
.related-chips a:hover { border-color: var(--accent); }

.ref-list { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 10px 18px; }
.ref-list a { color: var(--accent); font-size: 13.5px; text-decoration: none; }
.ref-list a:hover { text-decoration: underline; }

.topic-notfound { padding: 40px 0; text-align: center; color: var(--muted); }

/* ---------------- accuracy affordances (Req 3.4/3.5/10.1/10.2/10.4/10.5) ----
   Objective callout, narrative story hook, key-points summary, misconception
   callout, source disclosures, and interpretation labels. All use logical
   properties so they mirror correctly under RTL (design C.9). */

/* Learning-objective callout: a distinct accent-bordered note at the top. */
.t-objective.objective-callout { border-inline-start: 4px solid var(--accent); }
.t-objective.objective-callout p { color: var(--text); }

/* Narrative "story voice" hook: italic, quieter, visually distinct from claims. */
.story-block { background: var(--panel-2); border-inline-start: 4px solid var(--accent-2); }
.story-block p { font-style: italic; color: var(--text-soft); font-size: 15.5px; line-height: 1.7; }

/* End-of-lesson key-points summary. */
.key-points { margin: 0; padding-inline-start: 20px; display: grid; gap: 8px; }
.key-points li { color: var(--text-soft); font-size: 15px; line-height: 1.55; }

/* Misconception callout: a "myth vs. evidence" note, announced as role="note". */
.misconception {
  background: var(--panel); border: 1px solid var(--border); border-radius: 14px;
  border-inline-start: 4px solid var(--danger); padding: 18px 20px; display: grid; gap: 10px;
}
.misconception-head { display: flex; align-items: center; gap: 9px; font-weight: 600; font-size: 15px; }
.misconception-icon { color: var(--danger); font-size: 19px; font-weight: 700; }
.misconception p { margin: 0; color: var(--text-soft); font-size: 14.5px; line-height: 1.6; }
.misconception-tag {
  display: inline-block; font-size: 11px; font-weight: 600; letter-spacing: 0.4px;
  text-transform: uppercase; margin-inline-end: 6px;
}
.misconception-belief .misconception-tag { color: var(--danger); }
.misconception-correction .misconception-tag { color: var(--good); }
.misconception-source { font-size: 12.5px; }

/* Source disclosures: native <details>/<summary> per section, plus a catch-all. */
.sources { margin-top: 14px; border-top: 1px solid var(--border); padding-top: 12px; }
.sources > summary {
  cursor: pointer; font-size: 13px; font-weight: 600; color: var(--accent);
  display: flex; align-items: center; gap: 7px; list-style: none;
}
.sources > summary::-webkit-details-marker { display: none; }
.source-list { list-style: none; margin: 10px 0 0; padding: 0; display: grid; gap: 8px; }
.source-list li { font-size: 13px; color: var(--text-soft); line-height: 1.5; }
.source-cite { font-style: normal; }
.source-link { color: var(--accent); text-decoration: none; display: inline-flex; align-items: baseline; gap: 5px; }
.source-link:hover { text-decoration: underline; }

/* Interpretation vs. fact: each interpretive claim carries a labelled chip. */
.claim-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.claim { display: grid; gap: 5px; }
.claim-interpretation {
  justify-self: start; display: inline-block; font-size: 11px; font-weight: 600;
  letter-spacing: 0.4px; text-transform: uppercase; padding: 3px 9px; border-radius: 999px;
  background: var(--panel-2); color: var(--accent-2); border: 1px solid var(--border);
}
.claim-text { color: var(--text-soft); font-size: 14.5px; line-height: 1.6; }
.claim-source { font-size: 12.5px; }
.claim-source .source-link, .misconception-source .source-link { color: var(--accent); }

/* ---------------- moon-phase widget ---------------- */
.viz.moonphase { display: flex; flex-direction: column; }
/* min-height:0 lets the canvas shrink in the flex column (overriding the
   replaced-element default of min-height:auto), so the controls below are
   never pushed past the clipped edge of the .viz box. */
.moonphase-canvas { flex: 1 1 auto; min-height: 0; width: 100%; display: block; }
.moonphase-controls { flex-shrink: 0; padding: 10px 14px; border-top: 1px solid var(--border); display: flex; flex-direction: column; gap: 6px; background: var(--panel); }
.moonphase-label { font-size: 13px; font-weight: 600; color: var(--accent); text-align: center; }
.moonphase-date { font-size: 12px; color: var(--muted); text-align: center; }
.moonphase-reset { align-self: center; font-size: 12px; font-weight: 600; color: var(--accent); background: transparent; border: 1px solid var(--border); border-radius: 999px; padding: 3px 12px; cursor: pointer; transition: background .15s, border-color .15s; }
.moonphase-reset:hover { background: var(--panel-2, rgba(255,255,255,0.06)); border-color: var(--accent); }
.moonphase-slider { width: 100%; height: 24px; margin: 0; accent-color: var(--accent); cursor: pointer; }

/* ---------------- astrolabe widget ---------------- */
/* The aria-hidden canvas is ordered above the controls (it is appended after
   them by the shared canvas host), and the controls stack below like the
   moon-phase widget. */
.viz.astrolabe { display: flex; flex-direction: column; touch-action: none; }
.viz.astrolabe canvas { order: -1; flex: 1 1 auto; min-height: 0; cursor: grab; }
.viz.astrolabe canvas:active { cursor: grabbing; }
.astrolabe-controls { flex-shrink: 0; padding: 10px 14px; border-top: 1px solid var(--border); display: flex; flex-direction: column; gap: 8px; background: var(--panel); }
.astrolabe-fields { display: flex; flex-wrap: wrap; gap: 10px; }
.astrolabe-field { display: flex; flex-direction: column; gap: 3px; font-size: 12px; color: var(--muted); flex: 1 1 120px; }
.astrolabe-readout { margin: 0; font-size: 13px; font-weight: 600; color: var(--accent); text-align: center; }
.astrolabe-hint { margin: 0; font-size: 12px; color: var(--muted); text-align: center; }
.astrolabe-knob { align-self: center; font-size: 12px; font-weight: 600; color: var(--accent); background: transparent; border: 1px solid var(--border); border-radius: 999px; padding: 4px 14px; cursor: ew-resize; }
.astrolabe-knob::before { content: "\21ba \21bb"; margin-inline-end: 6px; }
.astrolabe-knob:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.viz.qibla { display: flex; flex-direction: column; }
.viz.qibla canvas { order: -1; flex: 1 1 auto; min-height: 0; }
.qibla-controls { flex-shrink: 0; padding: 10px 14px; border-top: 1px solid var(--border); display: flex; flex-direction: column; gap: 8px; background: var(--panel); }
.qibla-field { display: flex; flex-direction: column; gap: 3px; font-size: 12px; color: var(--muted); }
.qibla-readout { margin: 0; font-size: 13px; font-weight: 600; color: var(--accent); text-align: center; }
.qibla-hint { margin: 0; font-size: 12px; color: var(--muted); text-align: center; }

/* ---------------- responsive ---------------- */
@media (max-width: 980px) {
  .nav-links { display: none; }
  .nav-toggle { display: flex; }
  .nav-sim { display: none; }
  .portal-sidebar {
    position: fixed; top: 0; left: 0; bottom: 0; width: 270px; z-index: 50;
    max-height: none; height: 100vh; height: 100dvh; overflow-y: auto; background: var(--app-bg);
    transform: translateX(-100%); transition: transform 0.2s ease; padding-top: 70px;
  }
  body.sidebar-open .portal-sidebar { transform: translateX(0); box-shadow: 0 0 50px var(--shadow); }
  body.sidebar-open::after { content: ""; position: fixed; inset: 0; z-index: 45; background: rgba(0,0,0,0.5); }
  .topic-hero { grid-template-columns: 1fr; }
  .portal-main { padding: 22px 18px 60px; }
  .lang-select { font-size: 16px; } /* avoid iOS focus auto-zoom */
}

@media (max-width: 560px) {
  /* The action cluster (search/theme/font/audio/language) has a fixed minimum
     width that exceeds narrow phones - wider still with the Arabic language
     label - so the row must be allowed to wrap instead of forcing a 40px+
     horizontal document overflow (Req 13.5, both LTR and RTL). The auto
     inline-start margin keeps the cluster at the inline end whether it shares
     the brand's row or wraps onto its own. */
  .navbar { gap: 10px; row-gap: 8px; padding: 9px 14px; flex-wrap: wrap; }
  .nav-actions { gap: 6px; flex-wrap: wrap; justify-content: flex-end; min-width: 0; margin-inline-start: auto; }
  .nav-actions .icon-btn { width: 34px; height: 34px; }
  .lang-select { padding-block: 4px; padding-inline: 4px; }
  .nav-brand-text { font-size: 14px; }
  .portal-main { padding: 18px 14px 56px; }
  .portal-footer { padding: 18px 16px; }
  /* Single-column card grids on phones so nothing forces a horizontal scroll. */
  .domain-grid, .paths-grid, .continue-body, .sims-grid { grid-template-columns: 1fr; }
  .hero-dashboard { padding: 26px 18px; }
  .t-section { padding: 16px 16px; }
}

/* H1 - touch-target sizing for portal-only links on touch devices. Coarse
   pointers (touchscreens) get a >= 44x44 CSS-px hit area via min-height plus
   flex centring so the visible label stays centred; fine-pointer sizing above
   is intentionally left untouched. */
@media (pointer: coarse) {
  .path-steps a,
  .portal-sidebar a,
  .nav-links a {
    min-height: 44px;
    display: flex;
    align-items: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .domain-card, .link-card, .portal-sidebar { transition: none; }
}

/* ---------------- premium polish (elevation + motion) ---------------- */
.domain-card, .path-card, .sim-card, .link-card {
  box-shadow: var(--elev-1);
  transition: transform var(--t-med) var(--ease-out), box-shadow var(--t-med) var(--ease-out), border-color var(--t-med) ease;
}
.domain-card:hover, .sim-card:hover, .link-card:hover { transform: translateY(-4px); box-shadow: var(--elev-3); }
.path-card:hover { box-shadow: var(--elev-2); }
.hero-dashboard { box-shadow: var(--elev-2); }
.stat-tile { transition: transform var(--t-med) var(--ease-out), background var(--t-med) ease; }
.stat-tile:hover { transform: translateY(-2px); }
.badge-chip { transition: opacity var(--t-med) ease, filter var(--t-med) ease, border-color var(--t-med) ease, transform var(--t-fast) var(--ease-out); }
.badge-chip.got { animation: pop var(--t-med) var(--ease-spring); }
.domain-icon .svg-icon { transition: transform var(--t-med) var(--ease-spring); }
.domain-card:hover .domain-icon .svg-icon { transform: scale(1.12) rotate(-4deg); }

/* Path completion gets a celebratory sheen on its accent bar. */
.path-card.complete .path-progress > span { background: var(--grad-accent); box-shadow: 0 0 12px -2px var(--accent); }

@media (prefers-reduced-motion: reduce) {
  .domain-card, .path-card, .sim-card, .link-card, .stat-tile { transition: none; }
  .domain-card:hover, .sim-card:hover, .link-card:hover, .stat-tile:hover { transform: none; }
  .domain-card:hover .domain-icon .svg-icon { transform: none; }
  .badge-chip.got { animation: none; }
}

/* ---------------- path progress ring ---------------- */
.path-head-main { min-width: 0; }
.path-head .path-ring { flex-shrink: 0; }
.path-meta { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-top: 6px; }
.path-count { font-size: 11.5px; color: var(--muted); }
.path-ring .ring-track { stroke: color-mix(in srgb, var(--c, var(--accent)) 18%, var(--panel-2)); }
.path-card .ring-fill { stroke: var(--c, var(--accent)); }
.path-ring .ring-label { color: var(--c, var(--accent)); font-size: 12px; font-weight: 700; }
.path-card.complete .path-ring .ring-label { color: var(--good); }
.path-card.complete .ring-fill { stroke: var(--good); }

/* ---------------- onboarding (first-visit dashboard) ---------------- */
.stats-panel.onboarding { display: block;
  /* Opaque fallback first: below-baseline browsers ignore the color-mix()
     background below and keep this solid panel colour so the tint renders (C7). */
  background: var(--panel);
  background:
    radial-gradient(520px 200px at 90% -30%, color-mix(in srgb, var(--accent) 16%, transparent), transparent 70%),
    var(--panel); }
.onboarding-head { display: flex; gap: 14px; align-items: flex-start; }
.onboarding-icon { font-size: 30px; color: var(--accent); flex-shrink: 0; line-height: 1; }
.onboarding-head h2 { margin: 0 0 4px; font-size: 19px; }
.onboarding-head p { margin: 0; color: var(--muted); font-size: 14px; max-width: 60ch; }
.onboarding-steps { list-style: none; margin: 16px 0; padding: 0; display: grid; gap: 9px; }
.onboarding-steps li { display: flex; align-items: center; gap: 10px; font-size: 14px; color: var(--text-soft); }
.onboarding-step-icon { color: var(--accent-2); display: inline-flex; }
.onboarding-goals { margin-top: 16px; padding-top: 14px; border-top: 1px solid var(--rule); }
.onboarding-goals-title { font-size: 11px; text-transform: uppercase; letter-spacing: 1px; color: var(--muted); margin: 0 0 9px; }

/* ---------------- empty / error states ---------------- */
.empty-state {
  grid-column: 1 / -1; text-align: center; padding: 44px 22px; color: var(--muted);
  background: var(--panel); border: 1px dashed var(--border); border-radius: var(--r-lg);
}
.empty-state .empty-icon { display: inline-flex; font-size: 34px; color: var(--accent); margin-bottom: 12px; }
.empty-state h3 { margin: 0 0 6px; color: var(--text); font-size: 17px; }
.empty-state p { margin: 0 auto 16px; font-size: 14px; max-width: 44ch; }

/* Nicer topic-not-found uses the shared empty-state look. */
.topic-notfound.empty-state { margin: 40px auto; max-width: 520px; }

/* ---------------- guided path step navigation (pathnav.js) ---------------- */
/* Appended to the end of main content when the page is a learning-path step:
   path name + "Step i of N", a slim progress bar, and Previous/Next cards.
   Directional spacing/alignment uses logical properties so RTL mirrors. */
.pathnav { margin-top: 40px; padding-top: 18px; border-top: 1px solid var(--rule, var(--border)); }
.pathnav-head { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; flex-wrap: wrap; }
.pathnav-title { font-weight: 600; font-size: 13.5px; color: var(--accent-2); }
.pathnav-count { font-size: 12px; color: var(--muted); }
.pathnav-track {
  height: 5px; border-radius: 3px; margin: 10px 0 14px; overflow: hidden;
  background: var(--panel-2);
}
.pathnav-fill {
  display: block; height: 100%; border-radius: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transition: width 0.4s ease;
}
.pathnav-links { display: flex; justify-content: space-between; gap: 12px; }
.pathnav-link {
  display: flex; flex-direction: column; gap: 3px; flex: 1; max-width: 48%;
  min-height: 44px; padding: 10px 14px; text-decoration: none;
  background: var(--panel); border: 1px solid var(--border); border-radius: var(--r-md, 10px);
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.pathnav-link:hover { border-color: var(--accent); transform: translateY(-2px); }
.pathnav-link:focus-visible { outline: 2px solid var(--ring); outline-offset: 2px; }
.pathnav-link.placeholder { visibility: hidden; border: none; }
.pathnav-link.next { text-align: end; margin-inline-start: auto; }
.pathnav-link.prev { text-align: start; }
.pathnav-dir { font-size: 11.5px; text-transform: uppercase; letter-spacing: 0.6px; color: var(--muted); }
.pathnav-step { font-size: 14px; font-weight: 600; color: var(--accent); }
.pathnav-link.finish .pathnav-step { color: var(--good, var(--accent)); }
@media (max-width: 560px) {
  .pathnav-links { flex-direction: column; }
  .pathnav-link, .pathnav-link.next { max-width: none; margin-inline-start: 0; }
  .pathnav-link.placeholder { display: none; }
}
@media (pointer: coarse) {
  .pathnav-link { min-height: 44px; }
}
@media (prefers-reduced-motion: reduce) {
  .pathnav-fill, .pathnav-link { transition: none; }
  .pathnav-link:hover { transform: none; }
}

/* ---------------- Tonight's Sky panel + sky map (sky.js) ---------------- */
.tonight {
  background: var(--panel); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: 18px 20px; margin-bottom: 26px;
}
.sky-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.sky-head .section-title { margin: 0; }
.sky-city { display: inline-flex; align-items: center; gap: 8px; font-size: 12.5px; color: var(--muted); }
.sky-tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); gap: 10px; margin: 14px 0; }
.sky-tile {
  display: flex; flex-direction: column; gap: 2px; padding: 10px 12px;
  background: var(--panel-2); border: 1px solid var(--border); border-radius: var(--r-md, 10px);
}
.sky-tile-icon { color: var(--accent-2); display: inline-flex; }
.sky-tile-label { font-size: 11.5px; color: var(--muted); }
.sky-tile-value { font-size: 16px; font-weight: 600; color: var(--accent); }
.sky-planets { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.sky-planets-label { font-size: 12px; color: var(--muted); }
.sky-chip {
  display: inline-flex; align-items: center; gap: 6px; padding: 5px 11px;
  background: var(--panel-2); border: 1px solid var(--border); border-radius: 999px;
  font-size: 12.5px; min-height: 30px;
}
.sky-chip b { color: var(--accent); font-weight: 600; }
.sky-none { font-size: 12.5px; color: var(--muted); }
.sky-foot { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin: 14px 0 0; }
.sky-foot .hint { font-size: 11.5px; color: var(--muted); }

.skychart { max-width: 700px; }
.sky-controls { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin-bottom: 10px; }
.sky-time { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; }
.sky-time span { font-size: 15px; font-weight: 600; color: var(--accent); min-width: 64px; }
.sky-time input[type="range"] { flex: 1; accent-color: var(--accent); min-height: 32px; }
.sky-canvas-wrap { position: relative; display: flex; justify-content: center; }
.sky-canvas-wrap canvas { display: block; }
.sky-day {
  position: absolute; inset-block-start: 12px; inset-inline-start: 50%;
  transform: translateX(-50%); margin: 0; padding: 6px 14px;
  background: var(--panel); border: 1px solid var(--border); border-radius: 999px;
  font-size: 12px; color: var(--muted); white-space: nowrap;
}
[dir="rtl"] .sky-day { transform: translateX(50%); }

/* ---------------- Al-Sufi Arabic star-names layer (Req 6) ---------------- */
.sky-arabic { width: 100%; margin-bottom: 12px; }
.sky-arabic-toggle {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 13px; color: var(--text); cursor: pointer; min-height: 32px;
}
/* Modern custom checkbox: a rounded 20px tile that fills with the accent
   gradient when checked. Drawn with appearance:none + an inline-SVG check so
   it matches the theme in both modes; falls back to a native accent-colored
   box wherever appearance:none is unsupported. */
.sky-arabic-toggle input {
  accent-color: var(--accent-2); /* fallback path */
  appearance: none; -webkit-appearance: none;
  width: 20px; height: 20px; min-width: 20px; min-height: 20px;
  margin: 0; cursor: pointer;
  border: 2px solid var(--border); border-radius: 6px;
  background: var(--panel-2) center / 12px no-repeat;
  transition: border-color 0.15s ease, background-color 0.15s ease, box-shadow 0.15s ease;
}
.sky-arabic-toggle input:hover { border-color: var(--accent-2); }
.sky-arabic-toggle input:focus-visible { outline: none; box-shadow: var(--ring); }
.sky-arabic-toggle input:checked {
  border-color: var(--accent);
  background-color: var(--accent);
  background-image: url('data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="%23071018" stroke-width="4" stroke-linecap="round" stroke-linejoin="round"%3E%3Cpath d="M5 12.6l4.5 4.5L19 7"/%3E%3C/svg%3E');
}
/* Light theme: the accent is a deep teal, so the check flips to white. */
[data-theme="light"] .sky-arabic-toggle input:checked {
  background-image: url('data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="%23ffffff" stroke-width="4" stroke-linecap="round" stroke-linejoin="round"%3E%3Cpath d="M5 12.6l4.5 4.5L19 7"/%3E%3C/svg%3E');
}
.sky-names {
  display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px;
  max-height: 148px; overflow-y: auto; scrollbar-gutter: stable;
  padding: 10px; background: var(--panel);
  border: 1px solid var(--border); border-radius: var(--r-md, 10px);
}
.sky-name-btn {
  display: inline-flex; align-items: baseline; gap: 6px;
  padding: 5px 10px; border: 1px solid var(--border); border-radius: 999px;
  background: var(--panel); color: var(--text); cursor: pointer; font: inherit;
}
.sky-name-btn:hover { border-color: var(--accent-2); }
.sky-name-ar { font-size: 14px; color: #ffd86b; }
.sky-name-modern { font-size: 11.5px; color: var(--muted); }

.sky-star-popover {
  position: absolute; z-index: 4; max-width: 220px;
  display: flex; flex-direction: column; gap: 3px;
  padding: 12px 14px; background: var(--panel);
  border: 1px solid var(--accent-2); border-radius: 12px;
  box-shadow: 0 8px 26px rgba(0, 0, 0, 0.35);
  font-size: 12.5px; color: var(--text);
}
.sky-pop-close {
  position: absolute; inset-block-start: 4px; inset-inline-end: 6px;
  border: none; background: none; color: var(--muted);
  font-size: 18px; line-height: 1; cursor: pointer; padding: 2px 4px;
}
.sky-pop-arabic { font-size: 20px; font-weight: 700; color: #ffd86b; }
.sky-pop-translit { font-style: italic; color: var(--muted); }
.sky-pop-meaning { color: var(--text); }
.sky-pop-row { font-size: 12px; color: var(--muted); }

@media (pointer: coarse) {
  .sky-arabic-toggle { min-height: 44px; }
  .sky-name-btn { min-height: 44px; }
}

/* New Phase 12 directional icons point in the reading direction, so under RTL
   they mirror horizontally (11.4). The lesson-plan step chevron is a single
   `chevron-right` glyph reused for both directions via a transform mirror
   rather than a second icon. */
[dir="rtl"] .step-arrow,
[dir="rtl"] .step-arrow .svg-icon { transform: scaleX(-1); }

@media (pointer: coarse) {
  .sky-chip { min-height: 44px; }
  .sky-city select, .sky-city input, .sky-controls .btn { min-height: 44px; }
  .sky-time input[type="range"] { min-height: 44px; }
}
@media (max-width: 560px) {
  .sky-tiles { grid-template-columns: repeat(2, 1fr); }
  .sky-head { flex-direction: column; align-items: flex-start; }
}

/* ---------------- ISS passes + sky calendar + light pollution ---------------- */
.sky-bortle { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; flex-wrap: wrap; }
.sky-bortle > span:first-child { font-size: 12.5px; color: var(--muted); white-space: nowrap; }
.sky-bortle input[type="range"] { flex: 0 1 180px; accent-color: var(--accent-2); min-height: 32px; }
.sky-bortle-desc { font-size: 12px; color: var(--muted); flex: 1 1 220px; }

.sky-iss, .sky-events { margin-top: 34px; }
.iss-list { list-style: none; margin: 0 0 10px; padding: 0; display: grid; gap: 10px; }
.iss-pass {
  display: flex; align-items: baseline; gap: 8px 16px; flex-wrap: wrap;
  padding: 12px 16px; background: var(--panel);
  border: 1px solid var(--border); border-radius: var(--r-md, 10px);
  border-inline-start: 3px solid var(--border);
}
.iss-pass.watchable { border-inline-start-color: var(--good, var(--accent)); }
.iss-when { font-weight: 600; color: var(--accent); font-size: 14.5px; }
.iss-meta { color: var(--text); font-size: 13px; }
.iss-good { color: var(--good, var(--accent)); font-size: 12.5px; }
.iss-dim { color: var(--muted); font-size: 12.5px; }
.iss-stale { color: var(--danger); }

.sky-event-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.sky-event {
  display: flex; gap: 14px; padding: 14px 16px;
  background: var(--panel); border: 1px solid var(--border); border-radius: var(--r-md, 10px);
}
.sky-event.past { opacity: 0.55; }
.sky-event.next { border-color: var(--accent); }
.sky-event-icon { color: var(--accent-2); display: inline-flex; flex-shrink: 0; margin-top: 2px; }
.sky-event-body h3 { margin: 2px 0 4px; font-size: 15px; }
.sky-event-body p { margin: 0; font-size: 13px; color: var(--muted); line-height: 1.5; }
.sky-event-date { font-size: 12px; color: var(--accent); font-weight: 600; display: inline-flex; align-items: center; gap: 8px; }
.sky-event-next {
  font-size: 10.5px; text-transform: uppercase; letter-spacing: 0.6px;
  background: var(--accent); color: #06101f; padding: 2px 8px; border-radius: 999px;
}

@media (pointer: coarse) {
  .sky-bortle input[type="range"] { min-height: 44px; }
}

/* ---------------- constellation explorer (constellations.js) ---------------- */
.const-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 12px; margin-top: 18px;
}
.const-card {
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  padding: 14px 10px; cursor: pointer; min-height: 44px;
  background: var(--panel); color: var(--text);
  border: 1px solid var(--border); border-radius: var(--r-md, 10px);
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.const-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.const-card:focus-visible { outline: 2px solid var(--ring); outline-offset: 2px; }
.const-card.active { border-color: var(--accent); }
.const-card canvas { background: #0b1020; border-radius: 50%; }
.const-card-name { font-size: 13.5px; font-weight: 600; text-align: center; }
.const-latin { font-size: 11.5px; color: var(--muted); font-style: italic; }

.const-detail {
  background: var(--panel); border: 1px solid var(--accent);
  border-radius: var(--r-lg); padding: 18px 20px; outline: none;
}
.const-detail-grid { display: flex; gap: 22px; flex-wrap: wrap; align-items: flex-start; }
.const-canvas { background: #0b1020; border-radius: var(--r-md, 10px); flex-shrink: 0; }
.const-facts { flex: 1; min-width: 240px; }
.const-facts h2 { margin: 0 0 10px; font-size: 20px; display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.const-zodiac {
  font-size: 10.5px; text-transform: uppercase; letter-spacing: 0.6px;
  background: var(--accent-2); color: #06101f; padding: 2px 9px; border-radius: 999px;
}
.const-facts dl { margin: 0 0 12px; display: grid; gap: 6px; }
.const-facts dl > div { display: flex; gap: 8px; font-size: 13.5px; }
.const-facts dt { color: var(--muted); }
.const-facts dt::after { content: ":"; }
.const-facts dd { margin: 0; color: var(--accent); font-weight: 600; }
.const-story { font-size: 14px; line-height: 1.65; margin: 0 0 14px; }
.const-back { margin-bottom: 14px; }

@media (max-width: 560px) {
  .const-grid { grid-template-columns: repeat(2, 1fr); }
  .const-detail-grid { flex-direction: column; align-items: center; }
}

/* ---------------- worksheet / print CSS (teacher mode) ----------------
   Requirements 5.2, 5.3, 5.4, 5.5, 5.6. The printable Worksheet_View is the
   existing Topic_Page / Lesson_Plan_Page printed through pure print CSS - there
   is no separate render path to keep in sync. teacher.js adds `body.worksheet`
   before calling window.print(), but the print LAYOUT itself is declarative CSS
   and does not depend on JavaScript being enabled (5.6): the chrome-hiding and
   page geometry live in a plain `@media print` block so a no-JS Ctrl+P of the
   server-rendered <h1>/lead still prints clean, dark-on-white, and unclipped.
   Only the quiz answer-key withholding is scoped to `body.worksheet`, because a
   quiz only exists once JS has hydrated it. */

/* A4 and US Letter both print correctly in portrait with a comfortable margin;
   `size: portrait` lets each printer keep its own paper size (5.6). */
@page {
  size: portrait;
  margin: 16mm 15mm;
}

@media print {
  /* Dark text on a white background, body text >= 11pt, and nothing clipped
     beyond the printable page width (5.6). */
  :root { color-scheme: light; }
  html, body {
    background: #fff !important;
    color: #111 !important;
    font-size: 12pt;            /* body copy stays >= 11pt when printed (5.6) */
    line-height: 1.5;
  }

  /* Navigation chrome, the sidebar, and all interactive control clusters are
     excluded from the printout (5.2). */
  .navbar,
  .nav-actions,
  .nav-toggle,
  .portal-sidebar,
  .crumbs,
  .teacher-bar,
  .reading-level,
  .pathnav,
  .portal-footer,
  .site-footer,
  .skip-link { display: none !important; }

  /* Simulations and their reserved boxes are removed entirely so no empty
     placeholder space is left where a canvas/WebGL surface would sit (5.2).
     Hiding the whole `.t-tryit`/`.hero-sim` section (not just the `.viz`)
     avoids an orphaned "Try it" heading over blank space. */
  .viz,
  [data-scene],
  [data-moonphase],
  .hero-sim,
  .t-tryit { display: none !important; }

  /* Collapse the flex shell so lesson content flows full page width with no
     reserved sidebar gutter and no max-width clipping (5.2, 5.6). */
  .portal-shell { display: block !important; max-width: none !important; margin: 0 !important; }
  .portal-main {
    max-width: none !important; width: auto !important;
    padding: 0 !important; margin: 0 !important;
    overflow: visible !important;
  }

  /* Single-column hero and full-bleed media so images never overflow the page. */
  .topic-hero { display: block !important; }
  img { max-width: 100% !important; height: auto !important; }

  /* Lesson cards print as plain dark-on-white blocks and avoid breaking across
     pages mid-section where possible. */
  .t-section {
    background: #fff !important;
    border: 1px solid #999 !important;
    box-shadow: none !important;
    break-inside: avoid;
    page-break-inside: avoid;
  }
  h1, .lead,
  .t-section h2, .t-section p,
  .fact-pill dt, .fact-pill dd,
  .dyk-card, .related-chips a, .ref-list a { color: #111 !important; }

  /* The narration player is an interactive control; hide the player but leave
     the transcript text in place so the worksheet stays a full reading (5.2). */
  .audio audio,
  .audio video,
  audio, video { display: none !important; }

  /* Print links as plain text (no URL noise), keeping them dark-on-white. */
  a { color: #111 !important; text-decoration: none !important; }
}

/* Worksheet-scoped answer withholding (5.3): the printed worksheet keeps every
   quiz PROMPT but drops the choice buttons, the revealed `answer` index, the
   `explain` text, the "correct answer" phrase, and the score/result region, so
   students receive questions without an answer key. Scoped to `body.worksheet`
   so a teacher's deliberate worksheet print is the only place the key is
   stripped. The now-empty containers are collapsed to leave no blank gap under
   each prompt (5.2). */
@media print {
  body.worksheet .quiz-choices,
  body.worksheet .quiz-explain,
  body.worksheet .quiz-result,
  body.worksheet .quiz-correct-answer,
  body.worksheet .quiz-outcome { display: none !important; }

  body.worksheet .quiz-q { margin: 0 0 12pt !important; }
  body.worksheet .quiz-prompt { color: #111 !important; margin: 0; }
}

/* ---------------- scientist profiles + compare (scientists.js) ----------------
   Two surfaces share this block: the /scientists index (card grid) and a
   /scientists/{id} profile (bilingual header, vertical CSS timeline, expand-in-
   place discovery cards, impact/legacy). All directional spacing/alignment uses
   logical properties so the Arabic RTL layout mirrors automatically. */

/* --- profile index --- */
.sci-index-head { margin-bottom: 22px; }
.sci-index-head h1 { margin: 0 0 8px; }
.sci-compare-hint {
  display: inline-flex; align-items: center; gap: 8px; margin: 10px 0 0;
  font-size: 12.5px; color: var(--muted);
}
.sci-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 16px; margin-top: 10px;
}
.sci-card {
  display: flex; flex-direction: column; gap: 10px;
  padding: 16px 18px; background: var(--panel);
  border: 1px solid var(--border); border-radius: var(--r-lg);
  border-inline-start: 3px solid var(--c, var(--accent));
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.sci-card:hover { transform: translateY(-2px); }
.sci-card-link {
  display: flex; flex-direction: column; gap: 4px; text-decoration: none; color: inherit;
}
.sci-card-link:focus-visible { outline: 2px solid var(--ring); outline-offset: 3px; border-radius: 6px; }
.sci-card-ar { font-size: 20px; color: var(--accent); line-height: 1.4; }
.sci-card-en { font-size: 16px; font-weight: 600; color: var(--text); }
.sci-card-dates { font-size: 12px; color: var(--muted); }
.sci-card-summary { font-size: 13px; color: var(--muted); line-height: 1.55; margin-top: 2px; }
.sci-card-actions { margin-top: auto; }

/* Small "chip" variant of a button used for the index compare toggles. */
.btn-chip {
  display: inline-flex; align-items: center; gap: 6px; min-height: 34px;
  padding: 6px 12px; font-size: 12.5px; border-radius: 999px;
  background: var(--panel-2); color: var(--text); border: 1px solid var(--border);
  cursor: pointer; transition: border-color 0.15s ease, background 0.15s ease;
}
.btn-chip:hover { border-color: var(--accent); }
.sci-compare-toggle[aria-pressed="true"] { border-color: var(--accent); color: var(--accent); }
.sci-compare-toggle[disabled] { opacity: 0.5; cursor: not-allowed; }
.sci-compare-toggle:focus-visible { outline: 2px solid var(--ring); outline-offset: 2px; }

/* --- profile header --- */
.sci-header { align-items: center; }
.sci-header-body { min-width: 0; }
.sci-name-ar {
  font-size: 30px; line-height: 1.4; margin: 0 0 2px; color: var(--accent);
  font-weight: 600;
}
.sci-name-en { margin: 0 0 4px; font-size: 26px; }
.sci-translit { margin: 0 0 8px; font-size: 14px; color: var(--muted); font-style: italic; }
.sci-dates { margin: 0 0 12px; font-size: 13.5px; }
.sci-dates-span { font-weight: 600; color: var(--accent); }
.sci-dates-places { color: var(--muted); margin-inline-start: 8px; }
.sci-tags { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0 0; padding: 0; }
.sci-tags li {
  font-size: 11.5px; color: var(--muted); padding: 3px 10px;
  background: var(--panel-2); border: 1px solid var(--border); border-radius: 999px;
}
.sci-header-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-top: 16px; }

.sci-visual { margin: 0; }
.sci-visual img,
.sci-visual-fallback { width: 100%; border-radius: var(--r-lg); display: block; }
.sci-visual-fallback {
  aspect-ratio: 4 / 3;
  background: radial-gradient(120% 120% at 30% 20%, var(--c, var(--accent)) 0%, transparent 60%), var(--panel-2);
  border: 1px solid var(--border);
}
.sci-visual figcaption { font-size: 11px; color: var(--muted); margin-top: 6px; line-height: 1.5; }

/* --- vertical CSS timeline (Req 4.2, no library) --- */
.sci-timeline { list-style: none; margin: 6px 0 0; padding: 0; position: relative; }
.sci-timeline::before {
  content: ""; position: absolute; inset-block: 6px; inset-inline-start: 8px;
  width: 2px; background: var(--rule, var(--border));
}
.sci-tl-item { position: relative; padding-block: 0 20px; padding-inline-start: 34px; }
.sci-tl-item::before {
  content: ""; position: absolute; inset-inline-start: 2px; inset-block-start: 5px;
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--bg); border: 3px solid var(--accent);
  box-shadow: 0 0 10px -1px var(--accent);
}
.sci-tl-year { display: block; font-weight: 600; color: var(--accent); font-size: 13.5px; }
.sci-tl-body p { margin: 2px 0 0; font-size: 14px; line-height: 1.6; }
.sci-tl-src { display: block; margin-top: 4px; font-size: 11.5px; }

/* --- expand-in-place discovery cards (Req 4.3) --- */
.sci-disc-list { display: grid; gap: 10px; }
.sci-disc {
  background: var(--panel); border: 1px solid var(--border);
  border-radius: var(--r-md, 10px); border-inline-start: 3px solid var(--accent-2, var(--accent));
}
.sci-disc > summary {
  cursor: pointer; list-style: none; padding: 12px 16px; min-height: 44px;
  display: flex; align-items: center; gap: 10px; font-weight: 600;
}
.sci-disc > summary::-webkit-details-marker { display: none; }
.sci-disc > summary::after {
  content: "+"; margin-inline-start: auto; color: var(--accent);
  font-size: 20px; line-height: 1; transition: transform 0.15s ease;
}
.sci-disc[open] > summary::after { content: "\2212"; }
.sci-disc > summary:focus-visible { outline: 2px solid var(--ring); outline-offset: 2px; border-radius: 8px; }
.sci-disc-body { padding: 0 16px 14px; }
.sci-disc-body p { margin: 6px 0 0; font-size: 14px; line-height: 1.65; }
.sci-tag {
  font-size: 10.5px; text-transform: uppercase; letter-spacing: 0.5px;
  color: var(--accent-2, var(--accent)); font-weight: 700; margin-inline-end: 6px;
}
.sci-disc-legacy { color: var(--text); }
.sci-disc-src { font-size: 11.5px; }

/* --- compare tray (Req 4.4) --- */
.compare-tray {
  position: sticky; inset-block-end: 0; z-index: 5; margin-top: 30px;
  background: var(--panel); border: 1px solid var(--accent);
  border-radius: var(--r-lg); padding: 16px 18px;
  box-shadow: 0 -6px 24px -12px rgba(0, 0, 0, 0.5);
}
.compare-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.compare-head h2 { margin: 0; font-size: 16px; display: inline-flex; align-items: center; gap: 8px; }
.compare-count {
  font-size: 11.5px; color: var(--muted); background: var(--panel-2);
  border-radius: 999px; padding: 2px 9px;
}
.compare-chips { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.compare-chip {
  display: inline-flex; align-items: center; gap: 6px; padding: 5px 6px 5px 12px;
  background: var(--panel-2); border: 1px solid var(--border); border-radius: 999px;
  font-size: 12.5px;
}
.compare-chip-x {
  display: inline-flex; align-items: center; justify-content: center;
  width: 24px; height: 24px; min-width: 24px; padding: 0; border-radius: 50%;
  background: transparent; border: none; color: var(--muted); cursor: pointer;
}
.compare-chip-x:hover { color: var(--danger, var(--accent)); }
.compare-chip-x:focus-visible { outline: 2px solid var(--ring); outline-offset: 1px; }
.compare-hint { font-size: 13px; color: var(--muted); margin: 4px 0 0; }

.compare-table-wrap { overflow-x: auto; margin-top: 6px; }
.compare-table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.compare-table th, .compare-table td {
  padding: 9px 12px; text-align: start; vertical-align: top;
  border-block-end: 1px solid var(--border);
}
.compare-table thead th { color: var(--accent); font-weight: 600; }
.compare-table tbody th[scope="row"] { color: var(--muted); font-weight: 500; white-space: nowrap; }
.compare-table .compare-corner { color: var(--muted); font-weight: 500; }

@media (pointer: coarse) {
  .btn-chip, .compare-chip-x { min-height: 44px; }
  .sci-disc > summary { min-height: 44px; }
}
@media (max-width: 820px) {
  .sci-header { display: block; }
  .sci-visual { margin-top: 16px; max-width: 360px; }
}
@media (max-width: 560px) {
  .sci-grid { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  .sci-card, .btn-chip, .sci-disc > summary::after { transition: none; }
  .sci-card:hover { transform: none; }
}

/* ---------------- completion certificate (Req 7.7, task 12.5) ----------------
   /history/certificate. certificate.js renders one of two states into
   [data-certificate]: an encouraging "keep going" panel until all ten modules
   are complete, or the issued certificate (a name field + print button above a
   printable certificate sheet). All directional spacing uses logical properties
   so the Arabic RTL layout mirrors automatically. The @media print block below
   strips the chrome so a Ctrl+P / the Print button yields just the sheet. */

.certificate-page { margin-top: 8px; }

/* --- pending (not yet earned) state --- */
.cert-pending { text-align: center; max-width: 560px; margin: 20px auto; }
.cert-pending h2 { margin: 6px 0 8px; font-size: 22px; }
.cert-pending p { color: var(--muted); font-size: 15px; }
.cert-progress {
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  margin: 18px auto 20px; max-width: 340px;
}
.cert-progress-bar {
  width: 100%; height: 8px; border-radius: 999px;
  background: var(--panel-2); border: 1px solid var(--border); overflow: hidden;
}
.cert-progress-fill {
  display: block; height: 100%; border-radius: 999px;
  background: var(--grad-accent, var(--accent));
  transition: width 0.9s var(--ease-out, ease);
}
.cert-progress-label { font-size: 13px; color: var(--muted); font-weight: 600; }

/* --- issued: on-screen controls (hidden in print) --- */
.cert-controls {
  display: flex; align-items: flex-end; gap: 14px; flex-wrap: wrap;
  margin: 6px 0 22px;
}
.cert-name-field { display: flex; flex-direction: column; gap: 6px; flex: 1 1 260px; }
.cert-name-field span {
  font-size: 11px; text-transform: uppercase; letter-spacing: 1px;
  color: var(--muted); font-weight: 600;
}
.cert-name-field input {
  font: inherit; font-size: 15px; color: var(--text);
  padding: 10px 13px; border-radius: 9px;
  background: var(--panel-2); border: 1px solid var(--border);
}
.cert-name-field input:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; border-color: var(--accent); }

/* --- issued: the certificate sheet --- */
.certificate-sheet {
  position: relative; text-align: center;
  max-width: 720px; margin: 0 auto;
  padding: 44px 40px 38px;
  border-radius: 16px;
  border: 1px solid color-mix(in srgb, #c9a227 55%, var(--border));
  background:
    radial-gradient(120% 120% at 50% -10%, color-mix(in srgb, #c9a227 12%, transparent), transparent 60%),
    var(--panel);
  box-shadow: 0 0 0 1px color-mix(in srgb, #c9a227 40%, transparent), 0 18px 48px -22px rgba(0, 0, 0, 0.55);
}
.cert-seal {
  display: inline-flex; align-items: center; justify-content: center;
  width: 56px; height: 56px; margin: 0 auto 12px; border-radius: 50%;
  color: #1b1200; background: #c9a227;
  box-shadow: 0 0 0 5px color-mix(in srgb, #c9a227 30%, transparent);
}
.cert-seal svg { width: 30px; height: 30px; }
.cert-eyebrow {
  margin: 0 0 6px; font-size: 12px; text-transform: uppercase; letter-spacing: 2px;
  color: var(--accent-2); font-weight: 600;
}
.cert-heading { margin: 0 0 14px; font-size: clamp(24px, 4vw, 32px); }
.cert-intro { margin: 0 0 6px; color: var(--muted); font-size: 14.5px; }
.cert-name {
  margin: 4px 0 10px; font-size: clamp(26px, 5vw, 38px); font-weight: 700;
  color: var(--text); line-height: 1.15;
  border-bottom: 2px solid color-mix(in srgb, #c9a227 55%, var(--border));
  display: inline-block; padding: 0 18px 6px; min-width: 220px;
}
.cert-for { margin: 0 0 24px; color: var(--text-soft); font-size: 15px; }
.cert-for strong { color: var(--text); }
.cert-modules { margin: 0 auto 22px; max-width: 520px; text-align: start; }
.cert-modules h3 {
  margin: 0 0 10px; font-size: 13px; text-transform: uppercase; letter-spacing: 1px;
  color: var(--muted); text-align: center;
}
.cert-module-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.cert-module {
  display: flex; align-items: baseline; gap: 10px;
  padding: 8px 12px; border-radius: 9px;
  background: var(--panel-2); border: 1px solid var(--border);
}
.cert-module-ord {
  flex: 0 0 auto; font-size: 11.5px; font-weight: 700; letter-spacing: 0.4px;
  color: var(--accent-2); min-width: 76px;
}
.cert-module-title { flex: 1 1 auto; font-size: 14px; color: var(--text); }
.cert-date { margin: 0; color: var(--muted); font-size: 13.5px; }
.cert-date span { text-transform: uppercase; letter-spacing: 1px; font-size: 11px; font-weight: 600; }

/* Certificate print rules: on /history/certificate, strip the page hero and the
   on-screen controls so only the certificate sheet prints, and render the sheet
   as a clean dark-on-white bordered card that never breaks across pages. The
   global @media print block (above) already hides the navbar/sidebar/footer and
   forces the light colour scheme. */
@media print {
  body[data-page="certificate"] .hero-course,
  body[data-page="certificate"] .cert-controls { display: none !important; }

  body[data-page="certificate"] .certificate-sheet {
    max-width: none !important; margin: 0 !important;
    background: #fff !important; color: #111 !important;
    border: 2px solid #b8860b !important;
    box-shadow: none !important;
    break-inside: avoid; page-break-inside: avoid;
  }
  body[data-page="certificate"] .cert-eyebrow,
  body[data-page="certificate"] .cert-heading,
  body[data-page="certificate"] .cert-intro,
  body[data-page="certificate"] .cert-name,
  body[data-page="certificate"] .cert-for,
  body[data-page="certificate"] .cert-for strong,
  body[data-page="certificate"] .cert-modules h3,
  body[data-page="certificate"] .cert-module-title,
  body[data-page="certificate"] .cert-module-ord,
  body[data-page="certificate"] .cert-date { color: #111 !important; }

  body[data-page="certificate"] .cert-seal {
    color: #1b1200 !important; background: #d4af37 !important; box-shadow: none !important;
  }
  body[data-page="certificate"] .cert-module {
    background: #fff !important; border: 1px solid #999 !important;
  }
  body[data-page="certificate"] .cert-name { border-bottom-color: #b8860b !important; }
}

/* ---------------- collectible scientist cards (Req 7.6, task 12.3) ----------------
   A flip-card gallery on the dashboard ([data-cards]). Each card flips between a
   front face (rarity + bilingual name + collected/locked status) and a back face
   (what the astronomer is known for, or how to collect the card). cards.js
   toggles .is-flipped on the .card-collectible when its .card-flip button is
   activated (click or keyboard). The rotation is a pure CSS transform; the
   prefers-reduced-motion block below removes the animation so the faces still
   swap but do not spin (Req 12.6). All spacing uses logical properties for RTL. */

.cards-panel { margin: 8px 0 30px; padding: 18px 20px; background: var(--panel); border: 1px solid var(--border); border-radius: 14px; }
.cards-head h2 { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin: 0 0 4px; font-size: 18px; }
.cards-count { font-size: 13px; font-weight: 600; color: var(--accent); background: var(--panel-2); border-radius: 999px; padding: 2px 10px; }
.cards-sub { margin: 0 0 14px; font-size: 13.5px; color: var(--muted); }

.cards-gallery {
  list-style: none; margin: 0; padding: 0;
  display: grid; gap: 14px;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
}
.card-cell { display: flex; flex-direction: column; gap: 6px; }

/* The flip container. A fixed aspect ratio keeps the two faces the same size so
   the back is a true mirror of the front. Perspective enables the 3D rotate. */
.card-collectible { display: flex; flex-direction: column; gap: 6px; }
.card-flip {
  display: block; width: 100%; aspect-ratio: 3 / 4; padding: 0; border: none;
  background: transparent; cursor: pointer; perspective: 900px;
}
.card-flip:focus-visible { outline: 2px solid var(--ring); outline-offset: 3px; border-radius: 12px; }

.card-inner {
  position: relative; display: block; width: 100%; height: 100%;
  transform-style: preserve-3d; transition: transform var(--t-slow, 520ms) var(--ease-out, ease);
}
.card-collectible.is-flipped .card-inner { transform: rotateY(180deg); }

.card-face {
  position: absolute; inset: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 6px; text-align: center;
  padding: 12px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--panel-2);
  -webkit-backface-visibility: hidden; backface-visibility: hidden;
  overflow: hidden;
}
.card-front {
  border-color: color-mix(in srgb, var(--c, var(--accent)) 45%, var(--border));
  background: var(--panel-2);
  background: linear-gradient(160deg, color-mix(in srgb, var(--c, var(--accent)) 22%, var(--panel-2)), var(--panel-2));
}
.card-back { transform: rotateY(180deg); }

/* Portrait medallion: a circular frame for the astronomer's illustration,
   echoing a trading-card portrait window. Illustrations are drawn at 4/3 and
   sized generously here, so `contain` (not `cover`) keeps the whole scene
   inside the circle instead of cropping it. */
.card-portrait {
  width: 30%; aspect-ratio: 1; border-radius: 50%; flex: none; overflow: hidden;
  display: flex; align-items: center; justify-content: center;
  border: 2px solid var(--c, var(--accent));
  background: radial-gradient(120% 120% at 32% 22%, var(--c, var(--accent)) 0%, transparent 65%), var(--panel);
  box-shadow: 0 4px 14px -8px var(--c, var(--accent)), inset 0 0 0 1px color-mix(in srgb, var(--c, var(--accent)) 35%, transparent);
}
.card-portrait img { width: 100%; height: 100%; object-fit: contain; padding: 12%; display: block; }
.card-portrait-fallback { opacity: 0.55; }
.card-collectible.is-collected .card-portrait { box-shadow: 0 0 0 1px var(--c, var(--accent)), 0 4px 16px -6px var(--c, var(--accent)); }

.card-rarity { display: inline-flex; align-items: center; gap: 5px; font-size: 11px; font-weight: 700; letter-spacing: 0.04em; text-transform: uppercase; color: var(--c, var(--accent)); }
.card-ar { font-size: 17px; line-height: 1.3; }
.card-en { font-size: 14px; font-weight: 700; color: var(--text); line-height: 1.25; }
.card-dates { font-size: 11.5px; color: var(--muted); }
.card-status { margin-top: 4px; font-size: 10.5px; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase; color: var(--muted); }
.card-back-title { font-size: 12.5px; font-weight: 700; color: var(--accent); }
.card-known, .card-hint { font-size: 12.5px; color: var(--text); line-height: 1.4; }
.card-hint { color: var(--muted); }

/* Collected cards read full-colour; locked cards are muted + desaturated. */
.card-collectible.is-collected .card-front { box-shadow: 0 0 0 1px color-mix(in srgb, var(--c, var(--accent)) 30%, transparent), 0 6px 18px -10px var(--c, var(--accent)); }
.card-collectible.is-locked .card-front { filter: grayscale(0.85); opacity: 0.72; }
.card-collectible.is-collected .card-status { color: var(--good, var(--accent)); }

/* Rarity accents (fall back to the record's --c when unset). */
.card-collectible.rarity-gold { --c: #d4af37; }
.card-collectible.rarity-silver { --c: #c0c7d0; }
.card-collectible.rarity-bronze { --c: #cd7f32; }

.card-link { align-self: center; font-size: 12.5px; color: var(--accent); text-decoration: none; }
.card-link:hover { text-decoration: underline; }
.card-link:focus-visible { outline: 2px solid var(--ring); outline-offset: 2px; border-radius: 4px; }

@media (pointer: coarse) {
  .card-link { min-height: 44px; display: inline-flex; align-items: center; }
}
@media (max-width: 560px) {
  .cards-gallery { grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); }
}

/* Reduced motion: keep the flip functional (faces still swap) but drop the
   spinning transition so no non-essential animation plays (Req 12.6). */
@media (prefers-reduced-motion: reduce) {
  .card-inner { transition: none; }
}

/* ---------------- Daily challenge panel (paths.js, Req 7.3) ----------------
   A single date-keyed question shown beside Tonight's Sky. Options are real
   <button>s; the chosen/correct/wrong states reuse the quiz colour language.
   All spacing uses logical properties so the layout mirrors under RTL. */
.challenge-panel { margin-bottom: 26px; }
.challenge-card {
  background: var(--panel); border: 1px solid var(--border);
  border-radius: var(--r-lg); padding: 18px 20px;
}
.challenge-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.challenge-head .section-title { margin: 0; display: inline-flex; align-items: center; gap: 8px; }
.challenge-status {
  display: inline-flex; align-items: center; gap: 6px; font-size: 12px; font-weight: 700;
  color: var(--good, #5cf2a0); background: var(--panel-2);
  border: 1px solid var(--border); border-radius: 999px; padding: 4px 11px;
}
.challenge-sub { margin: 4px 0 12px; font-size: 13.5px; color: var(--muted); }
.challenge-q { margin: 0 0 12px; font-size: 15px; font-weight: 600; line-height: 1.4; }

.challenge-opts { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 8px; }
.challenge-opt {
  display: flex; align-items: center; gap: 9px; text-align: start; font-family: inherit;
  font-size: 14px; cursor: pointer; color: var(--text);
  background: var(--panel-2); border: 1px solid var(--border);
  border-radius: 9px; padding: 10px 13px;
  transition: border-color 0.12s ease, background 0.12s ease;
}
.challenge-opt:hover:not(:disabled) { border-color: var(--accent); }
.challenge-opt:disabled { cursor: default; }
.challenge-opt:focus-visible { outline: 2px solid var(--ring); outline-offset: 2px; }
.challenge-opt-mark {
  flex: none; display: inline-flex; align-items: center; justify-content: center;
  width: 22px; height: 22px; border-radius: 999px; font-size: 12px; font-weight: 700;
  background: var(--panel); border: 1px solid var(--border); color: var(--muted);
}
.challenge-opt.correct { border-color: #5cf2a0; background: rgba(92, 242, 160, 0.16); color: #d6ffe8; }
.challenge-opt.wrong { border-color: #ff6b6b; background: rgba(255, 107, 107, 0.16); color: #ffd9d9; }

.challenge-feedback { margin-top: 12px; }
.challenge-result { margin: 0; display: inline-flex; align-items: center; gap: 8px; font-weight: 600; }
.challenge-reward {
  font-size: 12.5px; font-weight: 700; color: var(--accent);
  background: var(--panel-2); border-radius: 999px; padding: 2px 10px;
}
.challenge-explain { margin: 9px 0 0; font-size: 13.5px; color: var(--text-soft, var(--muted)); padding: 9px 12px; border-radius: 8px; background: var(--panel-2); border-inline-start: 3px solid #5cf2a0; }
.challenge-hint { margin: 10px 0 0; font-size: 12.5px; color: var(--muted); }

@media (pointer: coarse) {
  .challenge-opt { min-height: 44px; }
}