/* Kelas Manajemen UT v2: design system
   Bahasa desain sama dengan v1: warm paper editorial, satu aksen
   terracotta, Fraunces display + Inter body + IBM Plex Mono label.
   Baru di v2: gerbang gaya belajar, chip gaya, dan empat koreografi
   halaman mata kuliah (visual, auditori, baca, praktik). */

:root {
  color-scheme: light;
  --paper: #faf5ec;
  --paper-raised: #fffdf8;
  --paper-sunk: #f2ead9;
  --ink: #211a12;
  --ink-soft: #57493a;
  --ink-faint: #77664c;
  --line: #ddd0ba;
  --line-strong: #c9b894;
  --line-input: #9a7f57;
  --accent: #bc4a1b;
  --accent-fill: var(--accent);
  --accent-deep: #96400f;
  --accent-tint: #f7e3d3;
  --ok: #3d6b35;
  --shadow: 0 18px 40px -22px rgba(84, 52, 20, 0.35);
  --radius: 18px;
  --font-display: "Fraunces", Georgia, "Times New Roman", serif;
  --font-body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, monospace;
  --topbar-h: 64px;
}

[data-theme="dark"] {
  color-scheme: dark;
  --paper: #16120d;
  --paper-raised: #201a13;
  --paper-sunk: #241c14;
  --ink: #f2e9da;
  --ink-soft: #c9bba6;
  --ink-faint: #96876f;
  --line: #3a2f22;
  --line-strong: #54432e;
  --line-input: #776446;
  --accent: #e8793f;
  --accent-fill: #b34a16;
  --accent-deep: #f0955c;
  --accent-tint: #3a2317;
  --ok: #8fc97f;
  --shadow: 0 18px 40px -22px rgba(0, 0, 0, 0.7);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background 0.35s ease, color 0.35s ease;
}

body.gate-open { overflow: hidden; }

::selection { background: var(--accent-fill); color: #fff; }

button { font-family: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* ---------- Top bar ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  min-height: var(--topbar-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px clamp(14px, 4vw, 40px);
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  color: var(--ink);
  min-width: 0;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--accent-fill);
  color: #fff;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1;
  flex: none;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 560;
  font-size: 19px;
  letter-spacing: 0.01em;
  white-space: nowrap;
}

.brand-name em { color: var(--accent); font-style: normal; }

.topbar-actions { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; justify-content: flex-end; }

.topbar-student {
  font-size: 12.5px;
  color: var(--ink-faint);
  font-family: var(--font-mono);
  white-space: nowrap;
}

.style-chip {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  gap: 8px;
  border: 1px solid var(--accent);
  background: var(--accent-tint);
  color: var(--accent-deep);
  border-radius: 999px;
  padding: 7px 13px;
  font: 600 13px var(--font-body);
  cursor: pointer;
  transition: transform 0.15s ease, background 0.2s ease;
}

.style-chip:hover { background: var(--paper-raised); }
.style-chip:active { transform: scale(0.97); }

.style-chip-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--accent);
  flex: none;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  gap: 7px;
  border: 1px solid var(--line-strong);
  background: var(--paper-raised);
  color: var(--ink);
  border-radius: 999px;
  padding: 7px 13px;
  font: 500 13px var(--font-body);
  cursor: pointer;
  transition: border-color 0.2s ease, transform 0.15s ease;
}

.theme-toggle:hover { border-color: var(--accent); }
.theme-toggle:active { transform: scale(0.97); }
.theme-toggle-icon { font-size: 15px; line-height: 1; }

/* ---------- Gerbang gaya belajar ---------- */
.gate {
  position: fixed;
  inset: 0;
  z-index: 90;
  overflow-y: auto;
  background: var(--paper);
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: clamp(20px, 5vh, 56px) clamp(16px, 4vw, 40px) max(48px, env(safe-area-inset-bottom));
}

.gate[hidden] { display: none; }

.gate-inner { position: relative; width: 100%; max-width: 880px; }

.gate-close {
  position: absolute;
  top: -6px;
  right: 0;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  background: var(--paper-raised);
  color: var(--ink);
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
}

.gate-close:hover { border-color: var(--accent); color: var(--accent); }

.gate-brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  font-family: var(--font-display);
  font-weight: 560;
  font-size: 18px;
  margin: 0 0 26px;
}

.gate-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(38px, 7.5vw, 64px);
  line-height: 1.02;
  letter-spacing: -0.015em;
  margin: 0 0 16px;
}

.gate-lede {
  font-size: clamp(16px, 2.2vw, 19px);
  line-height: 1.6;
  color: var(--ink-soft);
  max-width: 640px;
  margin: 0 0 34px;
}

.gate-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-bottom: 26px;
}

.gate-card {
  text-align: left;
  border: 1px solid var(--line-input);
  background: var(--paper-raised);
  border-radius: var(--radius);
  padding: 22px 22px 20px;
  cursor: pointer;
  color: var(--ink);
  transition: border-color 0.2s ease, transform 0.15s ease, box-shadow 0.2s ease;
  display: block;
  width: 100%;
}

.gate-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.gate-card:active { transform: scale(0.99); }

.gate-card.is-active { border-color: var(--accent); background: var(--accent-tint); }

.gate-card-glyph {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: var(--accent-fill);
  color: #fff;
  font-size: 24px;
  line-height: 1;
  margin-bottom: 14px;
}

.gate-card-name {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 24px;
  line-height: 1.15;
  margin-bottom: 6px;
}

.gate-card-tag {
  display: block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 8px;
}

.gate-card-desc { display: block; color: var(--ink-soft); font-size: 15px; line-height: 1.55; }

.gate-note { color: var(--ink-faint); font-size: 14px; margin: 0; }

/* ---------- Layout ---------- */
#app {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 clamp(16px, 4vw, 40px) 96px;
}

.view[hidden] { display: none; }

/* ---------- Hero ---------- */
.hero { padding: clamp(36px, 7vw, 84px) 0 8px; }

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 18px;
}

.hero-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(52px, 11vw, 108px);
  line-height: 0.98;
  letter-spacing: -0.015em;
  margin: 0 0 22px;
}

.hero-title-accent { color: var(--accent); }

.hero-tagline {
  font-size: clamp(17px, 2.4vw, 21px);
  line-height: 1.55;
  color: var(--ink-soft);
  max-width: 620px;
  margin: 0 0 18px;
}

.mode-line {
  max-width: 620px;
  margin: 0 0 40px;
  padding: 14px 18px;
  border-left: 4px solid var(--accent);
  background: var(--paper-raised);
  border-radius: 0 12px 12px 0;
  color: var(--ink);
  font-size: 15.5px;
  line-height: 1.6;
}

.mode-line:empty { display: none; }

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 28px;
}

.stat { background: var(--paper-raised); padding: 20px 22px; }

.stat-value {
  display: block;
  font-family: var(--font-display);
  font-weight: 560;
  font-size: clamp(22px, 3.4vw, 30px);
  line-height: 1.15;
}

.stat-of { font-size: 0.55em; color: var(--ink-faint); font-weight: 400; }

.stat-label {
  display: block;
  margin-top: 6px;
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--ink-faint);
  text-transform: uppercase;
}

.hero-progress { margin-bottom: 40px; }

.progress-track {
  height: 8px;
  border-radius: 999px;
  background: var(--paper-sunk);
  border: 1px solid var(--line);
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0;
  background: var(--accent);
  border-radius: 999px;
  transition: width 1.1s cubic-bezier(0.2, 0.7, 0.3, 1);
}

.progress-marks {
  display: flex;
  justify-content: space-between;
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-faint);
}

.progress-marks .mark-now { color: var(--accent); font-weight: 500; }

.progress-note { color: var(--ink-soft); max-width: 620px; margin: 12px 0 0; }

.hero-search { margin-bottom: 8px; }

.search-label {
  display: block;
  font-family: var(--font-display);
  font-weight: 560;
  font-size: 20px;
  margin-bottom: 10px;
}

.search-box {
  display: flex;
  align-items: center;
  gap: 10px;
  border: 1px solid var(--line-input);
  background: var(--paper-raised);
  border-radius: 14px;
  padding: 6px 16px;
  max-width: 640px;
}

.search-icon { color: var(--ink-faint); font-size: 18px; }

.search-box input {
  flex: 1;
  min-width: 0;
  border: 0;
  background: transparent;
  color: var(--ink);
  font: 400 16px var(--font-body);
  padding: 10px 0;
}

.search-box input:focus { outline: none; }
.search-box:focus-within { border-color: var(--accent); }

.search-hint { color: var(--ink-faint); font-size: 14px; margin: 10px 0 0; }

.no-result {
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  color: var(--ink-soft);
  margin-top: 32px;
}

.no-result-title { font-family: var(--font-display); font-size: 22px; color: var(--ink); margin: 0 0 6px; }

.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  border: 1px solid var(--line-strong);
  background: var(--paper-raised);
  color: var(--ink);
  border-radius: 999px;
  padding: 9px 18px;
  font: 500 14px var(--font-body);
  cursor: pointer;
  margin-top: 10px;
}

.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

.map-notice {
  margin: 28px 0 0;
  padding: 13px 18px;
  border: 1px solid var(--accent);
  background: var(--accent-tint);
  border-radius: 12px;
  color: var(--ink);
  font-size: 15px;
  max-width: 640px;
}

.map-notice[hidden] { display: none; }

/* ---------- Peta semester ---------- */
.semester-list { display: grid; gap: 44px; margin-top: 40px; }

.semester-head { display: flex; gap: 18px; align-items: flex-start; margin-bottom: 8px; }

.semester-num {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 54px;
  line-height: 0.9;
  color: var(--accent-tint);
  -webkit-text-stroke: 1.5px var(--accent);
  flex: none;
}

.semester-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 4vw, 34px);
  line-height: 1.1;
  margin: 4px 0 4px;
}

.semester-sub { color: var(--ink-soft); margin: 0; max-width: 640px; }

.semester-note {
  color: var(--ink-soft);
  background: var(--paper-sunk);
  border-radius: 12px;
  padding: 12px 16px;
  font-size: 14.5px;
  max-width: 760px;
}

.badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  color: var(--ink-soft);
  background: var(--paper-raised);
}

.badge-now { border-color: var(--accent); color: var(--accent-deep); background: var(--accent-tint); }

.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.course-card {
  text-align: left;
  border: 1px solid var(--line);
  background: var(--paper-raised);
  border-radius: 14px;
  padding: 16px 18px;
  cursor: pointer;
  color: var(--ink);
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 118px;
  transition: border-color 0.2s ease, transform 0.15s ease, box-shadow 0.2s ease;
  width: 100%;
}

.course-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.course-code {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--accent);
}

.course-name {
  font-family: var(--font-display);
  font-weight: 560;
  font-size: 19px;
  line-height: 1.25;
}

.course-foot {
  margin-top: auto;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 8px;
  font-size: 13px;
  color: var(--ink-faint);
}

.course-cta { color: var(--accent); font-weight: 600; white-space: nowrap; }

/* ---------- Halaman mata kuliah: kerangka bersama ---------- */
.subject { padding-top: clamp(28px, 5vw, 52px); }

.back-link {
  display: inline-block;
  padding: 10px 0;
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
  font-size: 15px;
}

.back-link:hover { text-decoration: underline; }

.subject-eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 26px 0 10px;
}

.subject-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(34px, 6.5vw, 58px);
  line-height: 1.04;
  letter-spacing: -0.01em;
  margin: 0 0 10px;
}

.subject-meta { font-family: var(--font-mono); font-size: 13px; color: var(--ink-faint); margin: 0 0 30px; }

.subject-section { margin-top: 44px; }

.subject-section > h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 3.6vw, 30px);
  margin: 0 0 8px;
}

.subject-section > p { color: var(--ink-soft); max-width: 680px; margin: 0 0 18px; }

.big-idea {
  border: 1px solid var(--line);
  border-left: 6px solid var(--accent);
  background: var(--paper-raised);
  border-radius: var(--radius);
  padding: clamp(20px, 4vw, 32px);
  margin-top: 6px;
}

.big-idea h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 22px;
  margin: 0 0 10px;
}

.big-idea p { font-size: 17.5px; line-height: 1.65; margin: 0; max-width: 720px; }

.analogi-line {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px dashed var(--line-strong);
  color: var(--ink-soft);
  font-size: 15.5px;
}

.analogi-line strong { color: var(--accent-deep); }

/* Peta topik mengalir (mode visual) */
.topic-flow { display: flex; flex-wrap: wrap; gap: 10px; align-items: stretch; }

.topic-box {
  flex: 1 1 205px;
  border: 1px solid var(--line);
  background: var(--paper-raised);
  border-radius: 14px;
  padding: 14px 16px;
}

.topic-box-num {
  display: inline-grid;
  place-items: center;
  min-width: 30px;
  height: 30px;
  padding: 0 6px;
  border-radius: 9px;
  background: var(--accent-fill);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  margin-bottom: 9px;
}

.topic-box-title { font-weight: 600; line-height: 1.35; margin: 0 0 5px; font-size: 15.5px; }
.topic-box-desc { color: var(--ink-soft); font-size: 13.5px; line-height: 1.5; margin: 0; }

.map-arrow { align-self: center; color: var(--accent); font-weight: 700; font-size: 18px; flex: none; }

/* Daftar topik vertikal (mode auditori) */
.topic-list { list-style: none; margin: 0; padding: 0; }

.topic-item {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: 4px 14px;
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
}

.topic-item:first-child { padding-top: 4px; }

.topic-num {
  grid-row: span 2;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--accent);
  padding-top: 2px;
}

.topic-title { font-weight: 600; margin: 0; line-height: 1.4; }
.topic-desc { color: var(--ink-soft); margin: 0; font-size: 15px; }

/* Kartu kunci (mode visual) */
.key-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(215px, 1fr)); gap: 12px; }

.key-card {
  border: 1px solid var(--line);
  border-top: 4px solid var(--accent);
  background: var(--paper-raised);
  border-radius: 14px;
  padding: 16px 18px;
}

.key-term { font-weight: 700; margin: 0 0 6px; line-height: 1.35; }
.key-gloss { color: var(--ink-soft); font-size: 14.5px; margin: 0; line-height: 1.55; }

/* Daftar kunci bernomor (mode baca) */
.key-list { margin: 0; padding-left: 22px; display: grid; gap: 10px; max-width: 720px; }
.key-list li { line-height: 1.6; }
.key-list .key-term { display: inline; }

/* Contoh */
.example-box {
  border: 1px solid var(--line);
  background: var(--paper-sunk);
  border-radius: var(--radius);
  padding: clamp(18px, 3.5vw, 28px);
}

.example-box h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 21px;
  margin: 0 0 10px;
}

.example-box p { margin: 0; line-height: 1.65; max-width: 720px; }

.calc {
  margin-top: 16px;
  background: var(--paper-raised);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 14px 18px;
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1.7;
  white-space: pre-line;
  overflow-x: auto;
}

/* Kuis */
.quiz-item {
  border: 1px solid var(--line);
  background: var(--paper-raised);
  border-radius: 14px;
  padding: 18px 20px;
  margin-bottom: 12px;
}

.quiz-q { font-weight: 600; margin: 0 0 12px; line-height: 1.5; }

.quiz-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  border: 1px solid var(--accent);
  background: transparent;
  color: var(--accent-deep);
  border-radius: 999px;
  padding: 7px 16px;
  font: 600 13.5px var(--font-body);
  cursor: pointer;
}

.quiz-btn:hover { background: var(--accent-tint); }

.quiz-a {
  display: none;
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line-strong);
  color: var(--ink-soft);
  line-height: 1.65;
}

.quiz-item.open .quiz-a { display: block; }

/* Audio */
.audio-hero {
  border: 1px solid var(--accent);
  background: var(--accent-tint);
  border-radius: var(--radius);
  padding: clamp(20px, 4vw, 32px);
  margin-top: 6px;
}

.audio-hero h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 4vw, 32px);
  margin: 0 0 8px;
}

.audio-hero p { color: var(--ink-soft); margin: 0 0 18px; max-width: 620px; }

.audio-hero audio, .audio-mini audio { width: 100%; display: block; }

.audio-mini {
  border: 1px solid var(--line);
  background: var(--paper-raised);
  border-radius: 14px;
  padding: 16px 18px;
}

.audio-mini p { margin: 0 0 10px; font-weight: 600; font-size: 14.5px; }

.audio-missing {
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  padding: 20px 22px;
  color: var(--ink-soft);
  background: var(--paper-raised);
}

.audio-missing strong { color: var(--ink); }

.transcript { margin-top: 20px; border: 1px solid var(--line-input); border-radius: 14px; background: var(--paper-raised); }

.transcript summary {
  cursor: pointer;
  font-weight: 600;
  padding: 15px 20px;
  list-style-position: inside;
}

.transcript-body { padding: 4px 20px 18px; color: var(--ink-soft); line-height: 1.7; max-width: 720px; }
.transcript-body p { margin: 0 0 12px; }

/* Kutipan ide besar (mode auditori) */
.pull-quote {
  margin: 6px 0 0;
  padding: 6px 0 6px 22px;
  border-left: 4px solid var(--accent);
}

.pull-quote p {
  font-family: var(--font-display);
  font-weight: 560;
  font-size: clamp(20px, 3.4vw, 27px);
  line-height: 1.4;
  margin: 0;
  max-width: 760px;
}

.pull-quote .analogi-line { border-top: 0; padding-top: 10px; font-family: var(--font-body); }

/* Mode baca: artikel + catatan */
.reading-lead {
  font-family: var(--font-display);
  font-weight: 560;
  font-size: clamp(19px, 3vw, 24px);
  line-height: 1.55;
  max-width: 720px;
  margin: 0 0 16px;
}

.reading-analogi { color: var(--ink-soft); font-size: 17px; line-height: 1.65; max-width: 720px; margin: 0; }

.reading-topic { max-width: 720px; padding: 16px 0 4px; border-bottom: 1px solid var(--line); }
.reading-topic h3 { font-family: var(--font-display); font-weight: 700; font-size: 20px; margin: 0 0 6px; }
.reading-topic p { color: var(--ink-soft); line-height: 1.7; margin: 0 0 12px; }

.notes-box { max-width: 720px; }

.notes-help { color: var(--ink-soft); margin: 0 0 12px; line-height: 1.6; }

.notes-area {
  width: 100%;
  min-height: 170px;
  border: 1px solid var(--line-input);
  border-radius: 14px;
  background: var(--paper-raised);
  color: var(--ink);
  font: 400 16px/1.65 var(--font-body);
  padding: 16px 18px;
  resize: vertical;
}

.notes-area:focus { outline: none; border-color: var(--accent); }

.notes-status { font-size: 13px; color: var(--ink-faint); margin: 8px 0 0; font-family: var(--font-mono); }

/* Mode praktik: kartu hafalan */
.flash-strip {
  display: flex;
  gap: 12px;
  overflow-x: auto;
  padding: 6px 2px 14px;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  -webkit-mask-image: linear-gradient(to right, #000 88%, transparent);
  mask-image: linear-gradient(to right, #000 88%, transparent);
}

.flash-note {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--ink-faint);
  margin: 0;
}

.flashcard {
  flex: 0 0 230px;
  height: 190px;
  scroll-snap-align: start;
  perspective: 900px;
  background: transparent;
  border: 0;
  padding: 0;
  cursor: pointer;
  text-align: left;
}

.flash-inner {
  display: block;
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.55s cubic-bezier(0.2, 0.7, 0.3, 1);
}

.flashcard.flipped .flash-inner { transform: rotateY(180deg); }

.flash-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: 14px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  overflow: hidden;
}

.flash-front {
  background: var(--accent-fill);
  color: #fff;
  justify-content: center;
}

.flash-front .flash-term {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 21px;
  line-height: 1.25;
}

.flash-hint { font-size: 12.5px; opacity: 0.85; font-family: var(--font-mono); }

.flash-back {
  background: var(--paper-raised);
  border: 1px solid var(--line-strong);
  color: var(--ink-soft);
  transform: rotateY(180deg);
  font-size: 14px;
  line-height: 1.55;
  overflow-y: auto;
}

.flash-back .flash-term { color: var(--ink); font-weight: 700; font-size: 14.5px; }

/* Navigasi antar mata kuliah */
.subject-nav {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  margin-top: 56px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  flex-wrap: wrap;
}

.subject-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--accent);
  font-weight: 600;
  text-decoration: none;
  max-width: 46%;
  line-height: 1.45;
}

.subject-nav a:hover { text-decoration: underline; }
.subject-nav .next { text-align: right; margin-left: auto; }

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--line);
  padding: 36px clamp(16px, 4vw, 40px) max(44px, env(safe-area-inset-bottom));
  max-width: 1120px;
  margin: 0 auto;
  color: var(--ink-soft);
  font-size: 14.5px;
}

.footer-title { font-family: var(--font-display); font-weight: 700; font-size: 19px; color: var(--ink); margin: 0 0 8px; }
.footer p { max-width: 680px; margin: 0 0 8px; line-height: 1.6; }
.footer-meta { font-family: var(--font-mono); font-size: 12px; color: var(--ink-faint); }
.footer-credit { font-family: var(--font-mono); font-size: 12px; color: var(--ink-faint); }
.footer-credit a { color: var(--accent); text-decoration: none; }
.footer-credit a:hover { text-decoration: underline; }

/* ---------- Animasi muncul ---------- */
.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.2, 0.7, 0.3, 1);
}

.reveal.shown { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .progress-fill { transition: none; }
  .flash-inner { transition: none; }
  body, .gate-card, .course-card, .style-chip, .theme-toggle { transition: none; }
  .gate-card:hover, .course-card:hover { transform: none; }
}

@supports not (-webkit-text-stroke: 1px black) {
  .semester-num { color: var(--accent); }
}

@media (max-width: 1120px) {
  .map-arrow { display: none; }
}

/* ---------- Layar kecil ---------- */
@media (max-width: 720px) {
  .topbar-student { display: none; }
  .brand-name { font-size: 17px; }
  .gate-grid { grid-template-columns: 1fr; }
  .stat { padding: 14px 12px; }
  .stat-value { font-size: 19px; }
  .stat-label { font-size: 11px; }
  .semester-num { font-size: 42px; }
  .course-grid { grid-template-columns: 1fr 1fr; }
  .topic-box { flex-basis: 100%; }
  .map-arrow { display: none; }
  .flashcard { flex-basis: 200px; height: 180px; }
  .subject-nav a { max-width: 100%; }
}

@media (max-width: 430px) {
  .course-grid { grid-template-columns: 1fr; }
  .theme-toggle-label { display: none; }
  .style-chip { padding: 7px 11px; }
  .topbar { flex-wrap: wrap; row-gap: 2px; }
  .topbar-actions { margin-left: auto; }
}