/* ============================================================
   School — frontend stylesheet
   Editorial, calm, modern. Warm ivory + ink + single accent.
   ============================================================ */

:root {
  /* canvas */
  --bg:        #F7F4EE;
  --bg-soft:   #F1ECE2;
  --bg-card:   #FFFFFF;
  --bg-elev:   #FFFFFF;

  /* ink */
  --ink:       #1A1815;
  --ink-2:     #3E3A33;
  --ink-3:     #6B655B;
  --ink-4:     #9B9384;
  --ink-5:     #C7BFAE;

  /* lines */
  --line:      #E5DECF;
  --line-2:    #D8D0BD;

  /* accent (rust/terracotta) */
  --accent:    #B8543A;
  --accent-2:  #9A3F26;
  --accent-soft: #F5E7DF;

  /* state */
  --success:   #3F6B47;
  --warn:      #B45309;

  /* type */
  --serif: "Newsreader", "Iowan Old Style", Georgia, serif;
  --sans:  "Geist", "Helvetica Neue", -apple-system, BlinkMacSystemFont, Arial, sans-serif;
  --mono:  "Geist Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  /* layout */
  --w-shell: 1240px;
  --w-text: 720px;
  --radius: 10px;
  --radius-lg: 18px;
  --shadow-sm: 0 1px 0 rgba(26,24,21,0.04), 0 1px 2px rgba(26,24,21,0.04);
  --shadow:    0 1px 0 rgba(26,24,21,0.05), 0 8px 24px -12px rgba(26,24,21,0.18);
  --shadow-lg: 0 2px 0 rgba(26,24,21,0.05), 0 30px 60px -28px rgba(26,24,21,0.30);
}

[data-theme="dark"] {
  --bg:        #14130F;
  --bg-soft:   #1B1A15;
  --bg-card:   #1F1D18;
  --bg-elev:   #25221C;
  --ink:       #F2EBDA;
  --ink-2:     #D6CFBE;
  --ink-3:     #A8A292;
  --ink-4:     #7B7669;
  --ink-5:     #4A463E;
  --line:      #2E2A23;
  --line-2:    #3A352C;
  --accent:    #E08469;
  --accent-2:  #F09C82;
  --accent-soft: #3A201A;
  --shadow-sm: 0 1px 0 rgba(0,0,0,0.4);
  --shadow:    0 1px 0 rgba(0,0,0,0.4), 0 16px 32px -16px rgba(0,0,0,0.6);
  --shadow-lg: 0 2px 0 rgba(0,0,0,0.4), 0 40px 80px -32px rgba(0,0,0,0.8);
}

/* reset */
*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  color: var(--ink);
  background: var(--bg);
  font-feature-settings: "ss01", "cv11";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color .25s ease, color .25s ease;
}
img, svg { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }

/* type helpers */
.serif { font-family: var(--serif); font-weight: 400; letter-spacing: -0.01em; }
.mono  { font-family: var(--mono); }
.eyebrow {
  font-family: var(--sans);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-3);
  font-weight: 500;
}
.muted { color: var(--ink-3); }
.tiny { font-size: 12.5px; }

/* ============================================================
   Top bar
   ============================================================ */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(140%) blur(14px);
  -webkit-backdrop-filter: saturate(140%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.topbar-inner {
  max-width: var(--w-shell);
  margin: 0 auto;
  padding: 14px 28px;
  display: flex;
  align-items: center;
  gap: 28px;
}
.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  cursor: pointer;
}
.brand-mark {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 500;
  letter-spacing: -0.02em;
  color: var(--ink);
  line-height: 1;
}
.brand-mark em {
  font-style: italic;
  color: var(--accent);
}
.brand-sub {
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.nav {
  display: flex;
  gap: 4px;
  margin-left: 20px;
}
.nav a {
  padding: 7px 12px;
  border-radius: 8px;
  font-size: 14px;
  color: var(--ink-2);
  font-weight: 450;
  transition: background-color .15s, color .15s;
}
.nav a:hover { background: var(--bg-soft); color: var(--ink); }
.nav a.active { color: var(--ink); background: var(--bg-soft); }
.topbar-spacer { flex: 1; }
.topbar-actions { display: flex; align-items: center; gap: 8px; }
.icon-btn {
  width: 36px; height: 36px;
  display: inline-flex;
  align-items: center; justify-content: center;
  border-radius: 9px;
  color: var(--ink-2);
  transition: background-color .15s, color .15s;
}
.icon-btn:hover { background: var(--bg-soft); color: var(--ink); }

.search {
  position: relative;
  display: flex;
  align-items: center;
  background: var(--bg-soft);
  border: 1px solid transparent;
  border-radius: 10px;
  padding: 7px 12px 7px 34px;
  min-width: 260px;
  transition: border-color .15s, background-color .15s;
}
.search:focus-within { border-color: var(--line-2); background: var(--bg-card); }
.search svg { position: absolute; left: 10px; color: var(--ink-3); }
.search input {
  width: 100%;
  background: transparent;
  border: 0;
  outline: 0;
  font: inherit;
  font-size: 14px;
  color: var(--ink);
}
.search input::placeholder { color: var(--ink-4); }
.search-kbd {
  font-family: var(--mono);
  font-size: 11px;
  padding: 2px 6px;
  border-radius: 4px;
  background: var(--bg-card);
  border: 1px solid var(--line);
  color: var(--ink-3);
}

/* ============================================================
   Page shell + sections
   ============================================================ */
.page { max-width: var(--w-shell); margin: 0 auto; padding: 56px 28px 120px; }
.page.narrow { max-width: 920px; }

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin: 0 0 22px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}
.section-head h2 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 26px;
  letter-spacing: -0.015em;
  margin: 0;
}
.section-head .right { color: var(--ink-3); font-size: 13.5px; }

/* ============================================================
   Hero (home)
   ============================================================ */
.hero {
  padding: 36px 0 18px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 72px;
  align-items: end;
}
.hero h1 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(48px, 6vw, 86px);
  letter-spacing: -0.03em;
  line-height: 0.98;
  margin: 14px 0 0;
  color: var(--ink);
  text-wrap: balance;
}
.hero h1 em {
  font-style: italic;
  color: var(--accent);
}
.hero-lede {
  font-size: 16.5px;
  color: var(--ink-2);
  max-width: 44ch;
  line-height: 1.55;
  margin-top: 22px;
}
.hero-side {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding-bottom: 6px;
  font-size: 13.5px;
  color: var(--ink-3);
  border-left: 1px solid var(--line);
  padding-left: 24px;
}
.hero-stat { display: flex; justify-content: space-between; gap: 12px; }
.hero-stat b { color: var(--ink); font-weight: 500; font-variant-numeric: tabular-nums; }

.hero-divider {
  height: 1px;
  background: var(--line);
  margin: 64px 0 40px;
}

/* ============================================================
   Filter chips
   ============================================================ */
.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 24px;
}
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 13px;
  font-size: 13px;
  font-weight: 450;
  color: var(--ink-2);
  background: transparent;
  border: 1px solid var(--line-2);
  border-radius: 999px;
  transition: background-color .15s, color .15s, border-color .15s;
}
.chip:hover { background: var(--bg-soft); }
.chip.active {
  background: var(--ink);
  color: var(--bg);
  border-color: var(--ink);
}
.chip small { opacity: .6; font-size: 11.5px; font-variant-numeric: tabular-nums; }

/* ============================================================
   Course grid
   ============================================================ */
.grid {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
.card {
  background: var(--bg-card);
  padding: 28px 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  position: relative;
  transition: background-color .15s;
  cursor: pointer;
  min-height: 230px;
}
.card:hover { background: var(--bg-elev); }
.card:hover .card-title { color: var(--accent); }
.card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}
.card-tag {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-3);
  font-weight: 500;
}
.card-tag .dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--card-accent, var(--accent));
  display: inline-block;
}
.card-meta {
  font-size: 12.5px;
  color: var(--ink-3);
  font-variant-numeric: tabular-nums;
}
.card-title {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 30px;
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 6px 0 0;
  transition: color .15s;
  text-wrap: balance;
}
.card-sub {
  font-family: var(--serif);
  font-style: italic;
  font-size: 17px;
  color: var(--ink-3);
  line-height: 1.3;
  margin: -4px 0 2px;
}
.card-blurb {
  font-size: 14px;
  color: var(--ink-2);
  line-height: 1.55;
  flex: 1;
}
.card-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12.5px;
  color: var(--ink-3);
  padding-top: 14px;
  border-top: 1px solid var(--line);
  margin-top: 2px;
}
.card-progress {
  display: flex;
  align-items: center;
  gap: 8px;
}
.card-progress-bar {
  width: 90px;
  height: 4px;
  border-radius: 999px;
  background: var(--bg-soft);
  overflow: hidden;
  position: relative;
}
.card-progress-bar > i {
  position: absolute;
  inset: 0;
  background: var(--card-accent, var(--accent));
  width: var(--p, 0%);
  border-radius: 999px;
  transition: width .35s ease;
  display: block;
}
.card-cta {
  color: var(--ink);
  font-weight: 500;
  display: inline-flex; align-items: center; gap: 4px;
}
.card-cta .arr { transition: transform .2s; }
.card:hover .arr { transform: translateX(3px); }

/* ============================================================
   Course page
   ============================================================ */
.course-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.8fr);
  gap: 64px;
  padding: 20px 0 56px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 48px;
  align-items: end;
}
.crumbs {
  display: flex; align-items: center; gap: 6px;
  font-size: 13px; color: var(--ink-3);
  margin-bottom: 18px;
}
.crumbs a { color: var(--ink-3); }
.crumbs a:hover { color: var(--ink); }
.crumbs .sep { color: var(--ink-4); }

.course-hero h1 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(40px, 5vw, 64px);
  letter-spacing: -0.025em;
  line-height: 1.02;
  margin: 12px 0 14px;
  text-wrap: balance;
}
.course-hero .sub {
  font-family: var(--serif);
  font-style: italic;
  font-size: clamp(20px, 2vw, 26px);
  color: var(--ink-3);
  margin: 0 0 22px;
  font-weight: 400;
}
.course-hero .lede {
  font-size: 16.5px;
  line-height: 1.6;
  color: var(--ink-2);
  max-width: 56ch;
}

.course-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px 24px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--bg-card);
}
.course-stat label {
  display: block;
  font-size: 11px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: 4px;
  font-weight: 500;
}
.course-stat value {
  display: block;
  font-family: var(--serif);
  font-size: 22px;
  color: var(--ink);
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
}

.course-actions {
  display: flex; gap: 10px; flex-wrap: wrap;
  margin-top: 20px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 18px;
  font-size: 14px;
  font-weight: 500;
  border-radius: 999px;
  transition: background-color .15s, color .15s, border-color .15s, transform .1s;
  border: 1px solid transparent;
}
.btn:active { transform: translateY(1px); }
.btn-primary {
  background: var(--ink);
  color: var(--bg);
}
.btn-primary:hover { background: var(--ink-2); }
.btn-accent {
  background: var(--accent);
  color: white;
}
.btn-accent:hover { background: var(--accent-2); }
.btn-ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--line-2);
}
.btn-ghost:hover { background: var(--bg-soft); }

/* ============================================================
   Course module table
   ============================================================ */
.module-table {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-card);
}
.module-row {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr) 130px 110px 28px;
  gap: 20px;
  padding: 20px 24px;
  align-items: center;
  cursor: pointer;
  border-top: 1px solid var(--line);
  transition: background-color .15s;
}
.module-row:first-child { border-top: 0; }
.module-row:hover { background: var(--bg-soft); }
.module-row:hover .module-title { color: var(--accent); }
.module-num {
  font-family: var(--serif);
  font-style: italic;
  font-size: 30px;
  color: var(--ink-4);
  line-height: 1;
  font-variant-numeric: lining-nums;
}
.module-row.done .module-num { color: var(--accent); }
.module-title {
  font-family: var(--serif);
  font-size: 21px;
  letter-spacing: -0.015em;
  color: var(--ink);
  line-height: 1.2;
  margin: 0 0 2px;
  transition: color .15s;
  font-weight: 400;
}
.module-sub {
  color: var(--ink-3);
  font-size: 13.5px;
  line-height: 1.4;
}
.module-meta {
  font-size: 12.5px;
  color: var(--ink-3);
  font-variant-numeric: tabular-nums;
}
.module-status {
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-weight: 500;
  color: var(--ink-3);
}
.module-status.done { color: var(--success); }
.module-status.progress { color: var(--accent); }
.module-row .arr { color: var(--ink-4); }

/* ============================================================
   Reader (module page)
   ============================================================ */
.reader {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 48px;
  align-items: start;
}
.reader-rail {
  position: sticky;
  top: 90px;
  font-size: 13.5px;
  align-self: start;
  max-height: calc(100vh - 110px);
  overflow-y: auto;
  padding-right: 6px;
}
.reader-rail h6 {
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin: 0 0 12px;
}
.rail-list { list-style: none; padding: 0; margin: 0 0 28px; }
.rail-list li { margin: 0; }
.rail-link {
  display: grid;
  grid-template-columns: 32px 1fr;
  align-items: baseline;
  gap: 8px;
  padding: 9px 10px;
  border-radius: 7px;
  color: var(--ink-2);
  transition: background-color .15s, color .15s;
  line-height: 1.3;
  border-left: 2px solid transparent;
  margin-left: -2px;
}
.rail-link:hover { background: var(--bg-soft); color: var(--ink); }
.rail-link.active {
  background: var(--bg-soft);
  color: var(--ink);
  border-left-color: var(--accent);
}
.rail-link .n {
  font-family: var(--serif);
  font-style: italic;
  color: var(--ink-4);
  font-size: 15px;
}
.rail-link.done .n { color: var(--success); }
.rail-link .t { font-size: 13.5px; }

.reader-main { max-width: var(--w-text); }
.reader-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  font-size: 13px;
  color: var(--ink-3);
  margin-bottom: 22px;
}
.reader-meta .pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--line-2);
  border-radius: 999px;
  background: var(--bg-card);
}

.prose {
  font-family: var(--serif);
  font-size: 19px;
  line-height: 1.65;
  color: var(--ink);
}
.prose h1 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(36px, 4vw, 52px);
  letter-spacing: -0.025em;
  line-height: 1.04;
  margin: 0 0 6px;
  text-wrap: balance;
}
.prose h2 {
  font-family: var(--serif);
  font-style: italic;
  font-weight: 400;
  font-size: 26px;
  line-height: 1.2;
  color: var(--ink-3);
  margin: 0 0 28px;
}
.prose h3 {
  font-family: var(--sans);
  font-weight: 600;
  font-size: 14px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink);
  margin: 44px 0 14px;
}
.prose h4 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 22px;
  letter-spacing: -0.01em;
  margin: 32px 0 10px;
}
.prose p { margin: 0 0 18px; text-wrap: pretty; }
.prose ul, .prose ol { padding-left: 22px; margin: 0 0 22px; }
.prose li { margin: 8px 0; }
.prose strong { font-weight: 600; color: var(--ink); }
.prose em { font-style: italic; }
.prose blockquote {
  margin: 22px 0;
  padding: 4px 0 4px 22px;
  border-left: 2px solid var(--accent);
  color: var(--ink-2);
  font-style: italic;
}
.prose code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--bg-soft);
  padding: 2px 6px;
  border-radius: 5px;
  color: var(--ink);
}
.prose pre {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
  overflow-x: auto;
  font-size: 13.5px;
  line-height: 1.55;
  margin: 22px 0;
}
.prose pre code {
  background: transparent;
  padding: 0;
  border-radius: 0;
  font-size: inherit;
}
.prose hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 36px 0;
}
.prose a { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }

/* reader footer nav */
.reader-foot {
  margin-top: 56px;
  padding-top: 28px;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.reader-foot a {
  padding: 18px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-card);
  transition: background-color .15s, border-color .15s;
}
.reader-foot a:hover { background: var(--bg-soft); border-color: var(--line-2); }
.reader-foot label {
  font-size: 11px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--ink-3);
  display: block;
  margin-bottom: 6px;
  font-weight: 500;
}
.reader-foot .ft {
  font-family: var(--serif);
  font-size: 17px;
  color: var(--ink);
  line-height: 1.25;
}
.reader-foot .next { text-align: right; }
.reader-foot .disabled {
  pointer-events: none;
  opacity: 0.35;
}

.complete-row {
  margin: 40px 0 0;
  padding: 22px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}
.complete-row .copy { font-size: 14.5px; color: var(--ink-2); }
.complete-row .copy b { color: var(--ink); font-weight: 600; }

/* ============================================================
   Quiz
   ============================================================ */
.quiz {
  margin-top: 64px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  overflow: hidden;
}
.quiz-head {
  padding: 24px 28px;
  border-bottom: 1px solid var(--line);
  background: var(--bg-soft);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.quiz-head h3 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 24px;
  letter-spacing: -0.01em;
  margin: 0 0 4px;
}
.quiz-head .quiz-meta { font-size: 13px; color: var(--ink-3); }
.quiz-body { padding: 24px 28px 28px; }
.q-item {
  padding: 20px 0;
  border-top: 1px solid var(--line);
}
.q-item:first-child { border-top: 0; padding-top: 6px; }
.q-num {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink-4);
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}
.q-text {
  font-family: var(--serif);
  font-size: 19px;
  line-height: 1.4;
  color: var(--ink);
  margin-bottom: 14px;
}
.q-options { display: flex; flex-direction: column; gap: 8px; }
.q-option {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 12px 14px;
  border: 1px solid var(--line-2);
  border-radius: var(--radius);
  cursor: pointer;
  background: var(--bg-card);
  transition: background-color .12s, border-color .12s;
  font-size: 14.5px;
  color: var(--ink);
}
.q-option:hover { background: var(--bg-soft); }
.q-option input { accent-color: var(--accent); margin-top: 3px; }
.q-option.correct {
  background: color-mix(in srgb, var(--success) 8%, var(--bg-card));
  border-color: var(--success);
}
.q-option.incorrect {
  background: color-mix(in srgb, var(--accent) 8%, var(--bg-card));
  border-color: var(--accent);
}
.q-input {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--line-2);
  border-radius: var(--radius);
  padding: 11px 14px;
  font: inherit;
  font-size: 15px;
  color: var(--ink);
  outline: 0;
  transition: border-color .15s;
}
.q-input:focus { border-color: var(--ink-3); }
.q-feedback {
  margin-top: 10px;
  font-size: 13.5px;
  padding: 10px 12px;
  border-radius: 7px;
  background: var(--bg-soft);
  border-left: 2px solid var(--ink-4);
  color: var(--ink-2);
  display: none;
}
.q-feedback.show { display: block; }
.q-feedback.right { border-left-color: var(--success); }
.q-feedback.wrong { border-left-color: var(--accent); }

.quiz-foot {
  padding: 18px 28px;
  border-top: 1px solid var(--line);
  background: var(--bg-soft);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.quiz-score {
  font-family: var(--serif);
  font-size: 20px;
  color: var(--ink);
}
.quiz-score b { color: var(--accent); font-weight: 500; }

/* ============================================================
   Empty / loading
   ============================================================ */
.center-state {
  padding: 80px 0;
  text-align: center;
  color: var(--ink-3);
}
.center-state h3 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 28px;
  color: var(--ink);
  margin: 0 0 10px;
  letter-spacing: -0.015em;
}
.center-state p { margin: 0 auto; max-width: 36ch; line-height: 1.55; }
.spinner {
  width: 18px; height: 18px; border-radius: 50%;
  border: 2px solid var(--line-2);
  border-top-color: var(--accent);
  animation: sp 0.9s linear infinite;
  display: inline-block;
}
@keyframes sp { to { transform: rotate(360deg); } }

/* ============================================================
   Footer
   ============================================================ */
footer {
  margin-top: 100px;
  border-top: 1px solid var(--line);
  background: var(--bg-soft);
  padding: 56px 0 60px;
}
.foot-inner {
  max-width: var(--w-shell);
  margin: 0 auto;
  padding: 0 28px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 36px;
}
.foot-brand {
  font-family: var(--serif);
  font-size: 28px;
  color: var(--ink);
  letter-spacing: -0.02em;
  margin-bottom: 10px;
}
.foot-brand em { font-style: italic; color: var(--accent); }
.foot-tag { color: var(--ink-3); font-size: 14px; max-width: 32ch; line-height: 1.55; }
.foot-col h6 {
  font-size: 11px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin: 0 0 14px;
  font-weight: 500;
}
.foot-col a {
  display: block;
  padding: 4px 0;
  font-size: 14px;
  color: var(--ink-2);
  transition: color .15s;
}
.foot-col a:hover { color: var(--accent); }
.foot-baseline {
  max-width: var(--w-shell);
  margin: 40px auto 0;
  padding: 22px 28px 0;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12.5px;
  color: var(--ink-4);
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 940px) {
  .hero { grid-template-columns: 1fr; gap: 30px; }
  .hero-side { border-left: 0; padding-left: 0; border-top: 1px solid var(--line); padding-top: 18px; }
  .grid { grid-template-columns: 1fr; }
  .course-hero { grid-template-columns: 1fr; gap: 36px; }
  .reader { grid-template-columns: 1fr; }
  .reader-rail { position: static; max-height: none; }
  .module-row { grid-template-columns: 40px 1fr 28px; gap: 14px; }
  .module-row .module-meta, .module-row .module-status { display: none; }
  .nav { display: none; }
  .search { display: none; }
  .foot-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 600px) {
  .page { padding: 32px 18px 80px; }
  .topbar-inner { padding: 12px 18px; }
  .reader-foot { grid-template-columns: 1fr; }
  .complete-row { flex-direction: column; align-items: flex-start; }
}

/* selection */
::selection { background: var(--accent); color: white; }

/* scrollbar (subtle, optional) */
.reader-rail::-webkit-scrollbar { width: 6px; }
.reader-rail::-webkit-scrollbar-thumb { background: var(--line-2); border-radius: 999px; }

/* ============================================================
   Auth badge + button-small
   ============================================================ */
.btn-sm { padding: 6px 12px; font-size: 13px; }
.auth-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 4px 10px 4px 4px;
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  transition: background-color .15s ease, border-color .15s ease;
}
.auth-badge:hover { background: var(--bg-soft); border-color: var(--line-2); }
.auth-avatar {
  width: 26px; height: 26px; border-radius: 999px; object-fit: cover;
  background: var(--accent-soft); color: var(--accent);
  display: inline-flex; align-items: center; justify-content: center;
  font-family: var(--serif); font-size: 14px; font-weight: 500;
}
.auth-avatar-initial { font-style: italic; }
.auth-name { font-size: 13px; color: var(--ink-2); max-width: 110px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.auth-pill {
  font-size: 10px; letter-spacing: 0.1em;
  background: var(--accent); color: white;
  padding: 2px 6px; border-radius: 4px;
}

/* ============================================================
   Modal
   ============================================================ */
.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(26, 24, 21, 0.55);
  backdrop-filter: blur(4px);
  display: flex; align-items: flex-start; justify-content: center;
  padding: 80px 24px 24px;
  z-index: 1000;
}
[data-theme="dark"] .modal-overlay { background: rgba(0,0,0,0.7); }
.modal {
  background: var(--bg-card);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  width: 100%; max-width: 480px;
  max-height: calc(100vh - 120px);
  overflow-y: auto;
  padding: 24px 28px 28px;
}
.modal-head {
  display: flex; justify-content: space-between; align-items: center;
  margin-bottom: 18px;
}
.modal-head h3 { font-family: var(--serif); font-weight: 500; margin: 0; font-size: 22px; }
.modal-head .icon-btn { font-size: 22px; line-height: 1; padding: 0 8px; color: var(--ink-3); }
.modal-error {
  background: #fff1ee; color: var(--accent-2);
  border: 1px solid #f3d4c8; border-radius: 8px;
  padding: 10px 14px; font-size: 13px; margin-bottom: 14px;
}
[data-theme="dark"] .modal-error { background: rgba(224,132,105,0.12); border-color: rgba(224,132,105,0.35); color: var(--accent-2); }
.modal-actions { display: flex; gap: 10px; justify-content: flex-end; margin-top: 18px; flex-wrap: wrap; }

/* ============================================================
   Auth form
   ============================================================ */
.auth-form { display: flex; flex-direction: column; gap: 12px; }
.auth-tabs { display: flex; gap: 4px; padding: 4px; background: var(--bg-soft); border-radius: 10px; margin-bottom: 4px; }
.auth-tab { flex: 1; padding: 8px 12px; border-radius: 8px; font-size: 13.5px; color: var(--ink-3); }
.auth-tab.active { background: var(--bg-card); color: var(--ink); box-shadow: var(--shadow-sm); }
.auth-divider {
  display: flex; align-items: center; gap: 10px; color: var(--ink-4); font-size: 12px; margin: 6px 0;
}
.auth-divider::before, .auth-divider::after { content: ''; flex: 1; height: 1px; background: var(--line); }
.auth-oauth { display: flex; flex-direction: column; gap: 8px; }
.auth-oauth .btn { justify-content: center; }

/* ============================================================
   Account modal
   ============================================================ */
.account-body p { margin: 12px 0; }

/* ============================================================
   AI tutor / summary / flashcards
   ============================================================ */
.ai-bar { display: flex; gap: 10px; flex-wrap: wrap; margin: 24px 0 18px; padding: 14px; background: var(--bg-soft); border: 1px solid var(--line); border-radius: var(--radius); }
.ai-tutor .ai-log {
  height: 320px; overflow-y: auto;
  border: 1px solid var(--line); border-radius: 10px;
  padding: 12px; background: var(--bg);
  margin: 10px 0 12px;
  display: flex; flex-direction: column; gap: 10px;
}
.ai-msg { padding: 10px 12px; border-radius: 10px; font-size: 14px; line-height: 1.5; }
.ai-msg-user { background: var(--accent-soft); align-self: flex-end; max-width: 85%; }
.ai-msg-assistant { background: var(--bg-card); border: 1px solid var(--line); max-width: 85%; }
.ai-role { font-size: 10.5px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-4); margin-bottom: 4px; }
.ai-thinking .ai-text { font-style: italic; }
.ai-input-row { display: flex; gap: 8px; }
.ai-input-row .q-input { flex: 1; }

.flashcard-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 12px; margin-top: 12px; }
.flashcard {
  perspective: 1000px;
  height: 140px; cursor: pointer;
  position: relative;
}
.flashcard-front, .flashcard-back {
  position: absolute; inset: 0;
  border: 1px solid var(--line); border-radius: 10px;
  padding: 14px; display: flex; flex-direction: column; justify-content: center;
  backface-visibility: hidden;
  transition: transform .4s ease;
  font-size: 13.5px; line-height: 1.4;
  background: var(--bg-card);
}
.flashcard-back { transform: rotateY(180deg); background: var(--accent-soft); }
.flashcard.flipped .flashcard-front { transform: rotateY(180deg); }
.flashcard.flipped .flashcard-back { transform: rotateY(360deg); }
.flashcard-n { font-family: var(--mono); font-size: 11px; color: var(--ink-4); margin-bottom: 6px; }

/* ============================================================
   Spinner
   ============================================================ */
.spinner {
  display: inline-block; width: 22px; height: 22px;
  border: 2px solid var(--line-2); border-top-color: var(--accent);
  border-radius: 50%; animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }


/* ============================================================
   Phase 1–6 components
   ============================================================ */

/* Notif bell */
.notif-bell { position: relative; }
.notif-dot {
  position: absolute; top: -4px; right: -4px;
  min-width: 16px; height: 16px; padding: 0 4px; border-radius: 999px;
  background: var(--accent); color: white; font-size: 10px;
  display: inline-flex; align-items: center; justify-content: center;
  font-weight: 600;
}
.notif-list { display: flex; flex-direction: column; gap: 8px; max-height: 60vh; overflow-y: auto; }
.notif-item {
  padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px;
  cursor: pointer; background: var(--bg-card);
}
.notif-item:hover { background: var(--bg-soft); }
.notif-item.read { opacity: 0.55; }
.notif-title { font-weight: 500; margin-bottom: 2px; }

/* Account modal links */
.account-links { display: flex; flex-direction: column; gap: 6px; padding: 8px 0; }
.account-links a { color: var(--ink); padding: 6px 0; border-bottom: 1px solid var(--line); }
.account-links a:hover { color: var(--accent); }

/* Comments + composer */
.comments-section { margin-top: 32px; padding-top: 24px; border-top: 1px solid var(--line); }
.comments-section h3 { font-size: 16px; margin-bottom: 12px; }
.comments-list { display: flex; flex-direction: column; gap: 10px; margin-bottom: 14px; }
.comment-item {
  background: var(--bg-soft); border: 1px solid var(--line);
  border-radius: 8px; padding: 10px 12px;
}
.comment-item header { font-size: 12.5px; margin-bottom: 4px; color: var(--ink-3); }
.comment-body { font-size: 14px; line-height: 1.5; white-space: pre-wrap; word-break: break-word; }
.comments-composer { display: flex; flex-direction: column; gap: 6px; }

/* Notes panel */
.notes-panel { margin-top: 32px; padding: 16px; background: var(--bg-soft); border: 1px solid var(--line); border-radius: var(--radius); }
.notes-head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 8px; }
.notes-head h3 { font-size: 15px; margin: 0; }
.notes-ta { width: 100%; min-height: 90px; padding: 10px; border: 1px solid var(--line); border-radius: 8px; background: var(--bg-card); color: var(--ink); font: inherit; resize: vertical; }
.notes-ta:disabled { opacity: 0.5; cursor: not-allowed; }

/* Cert verify */
.cert-verify-ok { padding: 40px; background: var(--accent-soft); border: 2px solid var(--accent); border-radius: 12px; text-align: center; }
.cert-verify-ok h1 { font-size: 32px; margin: 8px 0; }
.cert-verify-bad { padding: 40px; text-align: center; color: var(--ink-3); }

/* Review (FSRS) */
.review-card { padding: 24px; background: var(--bg-card); border: 1px solid var(--line); border-radius: 12px; }
.review-card .flashcard-front { font-size: 18px; margin: 16px 0; min-height: 60px; }
.review-card .flashcard-back { font-size: 16px; margin: 16px 0; padding-top: 12px; border-top: 1px solid var(--line); color: var(--ink-2); }
.review-card .grades { display: flex; flex-wrap: wrap; }

/* Community feed */
.feed { display: flex; flex-direction: column; gap: 14px; }
.composer-wrap { margin-bottom: 18px; padding: 12px; border: 1px solid var(--line); border-radius: 10px; background: var(--bg-card); }
.composer { width: 100%; padding: 10px; border: 1px solid var(--line); border-radius: 8px; resize: vertical; background: var(--bg-card); color: var(--ink); }
.post-card { padding: 14px; background: var(--bg-card); border: 1px solid var(--line); border-radius: 10px; }
.post-head { display: flex; gap: 10px; align-items: center; margin-bottom: 8px; }
.post-name { font-weight: 500; }
.post-body { line-height: 1.55; }
.post-foot { display: flex; gap: 10px; align-items: center; margin-top: 8px; padding-top: 8px; border-top: 1px solid var(--line); }

/* AI fab */
.ai-fab {
  position: fixed; right: 18px; bottom: 80px; z-index: 90;
  width: 52px; height: 52px; border-radius: 999px;
  background: var(--accent); color: white;
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; box-shadow: var(--shadow);
  border: 0; cursor: pointer;
}
.ai-fab:hover { background: var(--accent-2); }
@media (min-width: 900px) { .ai-fab { bottom: 24px; } }

/* Mobile bottom nav */
.bottom-nav {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 80;
  display: none; justify-content: space-around; padding: 8px 6px 12px;
  background: var(--bg-card); border-top: 1px solid var(--line);
}
.bottom-nav a {
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  font-size: 11px; color: var(--ink-3); padding: 4px 8px; border-radius: 8px;
}
.bottom-nav a.active { color: var(--accent); background: var(--accent-soft); }
.bottom-nav a span { font-size: 18px; }
@media (max-width: 900px) {
  .bottom-nav { display: flex; }
  body { padding-bottom: 70px; }
  .ai-fab { bottom: 80px; }
}

/* Search results */
.search-results { display: flex; flex-direction: column; gap: 8px; margin-top: 16px; }
.search-hit { display: block; padding: 10px 12px; background: var(--bg-card); border: 1px solid var(--line); border-radius: 8px; color: var(--ink); }
.search-hit:hover { background: var(--bg-soft); }

/* Admin table */
.admin-table { width: 100%; border-collapse: collapse; font-size: 13px; margin-top: 10px; }
.admin-table th, .admin-table td { padding: 8px; border-bottom: 1px solid var(--line); text-align: left; }
.admin-table th { color: var(--ink-3); font-weight: 500; }

/* Onboarding */
.onboarding-form { display: flex; flex-direction: column; gap: 12px; margin-top: 16px; }
.onboarding-form label { display: flex; flex-direction: column; gap: 6px; font-size: 13px; color: var(--ink-3); }
.onboarding-output { margin-top: 20px; }

/* Profile card */
.profile-card h1 { margin-bottom: 4px; }
.profile-card ul { padding-left: 18px; }
.profile-card li { margin: 4px 0; }