:root {
  --bg: #f4efe7;
  --bg-strong: #efe4d1;
  --paper: rgba(255, 251, 245, 0.92);
  --paper-strong: #fffaf1;
  --ink: #202420;
  --muted: #5f645c;
  --line: rgba(32, 36, 32, 0.12);
  --accent: #d96c34;
  --accent-deep: #9f3815;
  --accent-soft: #f4c895;
  --teal: #2c7f7b;
  --gold: #b78d2e;
  --shadow: 0 24px 60px rgba(58, 43, 18, 0.12);
  --radius-xl: 28px;
  --radius-lg: 22px;
  --radius-md: 16px;
  --radius-sm: 12px;
  --heading-font: "BiauKai", "Noto Serif TC", "Songti TC", serif;
  --body-font: "Avenir Next", "PingFang TC", "Noto Sans TC", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(217, 108, 52, 0.2), transparent 28%),
    radial-gradient(circle at 85% 18%, rgba(44, 127, 123, 0.18), transparent 24%),
    linear-gradient(180deg, #f7f1e7 0%, #efe5d4 100%);
  font-family: var(--body-font);
}

button,
input {
  font: inherit;
}

.page-shell {
  width: min(1400px, calc(100vw - 32px));
  margin: 0 auto;
  padding: 32px 0 48px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.8fr);
  gap: 20px;
  padding: 28px;
  background:
    linear-gradient(135deg, rgba(255, 250, 241, 0.92), rgba(243, 230, 207, 0.92)),
    repeating-linear-gradient(
      -35deg,
      rgba(217, 108, 52, 0.06),
      rgba(217, 108, 52, 0.06) 18px,
      rgba(255, 255, 255, 0) 18px,
      rgba(255, 255, 255, 0) 36px
    );
  border: 1px solid rgba(255, 255, 255, 0.6);
  border-radius: 36px;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto -80px -80px auto;
  width: 240px;
  height: 240px;
  background: radial-gradient(circle, rgba(44, 127, 123, 0.18), transparent 70%);
}

.eyebrow,
.module-tag {
  margin: 0 0 10px;
  color: var(--accent-deep);
  font-size: 0.86rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.hero h1,
.module-heading h2,
.panel h3 {
  font-family: var(--heading-font);
}

.hero h1 {
  margin: 0;
  font-size: clamp(2rem, 3vw, 3.6rem);
  line-height: 1.1;
  max-width: 12ch;
}

.hero-text {
  max-width: 60ch;
  color: var(--muted);
  line-height: 1.8;
  margin: 18px 0 0;
}

.exam-alert {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 18px;
  padding: 12px 16px;
  border-radius: 999px;
  background: rgba(159, 56, 21, 0.08);
  border: 1px solid rgba(159, 56, 21, 0.14);
  color: var(--accent-deep);
  font-weight: 600;
}

.motivation-alert {
  margin-top: 12px;
  padding: 14px 16px;
  border-radius: 18px;
  background: rgba(44, 127, 123, 0.1);
  border: 1px solid rgba(44, 127, 123, 0.18);
  color: #245955;
  line-height: 1.7;
  max-width: 54ch;
}

.hero-actions,
.quiz-actions {
  display: flex;
  gap: 12px;
  margin-top: 24px;
  flex-wrap: wrap;
}

.hero-utility {
  display: flex;
  gap: 12px;
  margin-top: 10px;
}

.primary-btn,
.ghost-btn,
.module-btn,
.option-card,
.flashcard,
.tool-tab,
.text-btn {
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease, border-color 180ms ease;
}

.primary-btn,
.ghost-btn {
  border-radius: 999px;
  border: 1px solid transparent;
  padding: 12px 18px;
  cursor: pointer;
}

.primary-btn {
  background: linear-gradient(135deg, var(--accent), var(--accent-deep));
  color: #fff7ef;
  box-shadow: 0 10px 24px rgba(159, 56, 21, 0.24);
}

.ghost-btn {
  background: rgba(255, 250, 241, 0.82);
  color: var(--ink);
  border-color: var(--line);
}

.text-btn {
  border: none;
  background: transparent;
  padding: 2px 0;
  color: var(--muted);
  cursor: pointer;
}

.compact {
  padding: 9px 14px;
  font-size: 0.92rem;
}

.primary-btn:hover,
.ghost-btn:hover,
.module-btn:hover,
.option-card:hover,
.flashcard:hover,
.tool-tab:hover,
.text-btn:hover {
  transform: translateY(-2px);
}

.hero-panel {
  display: grid;
  gap: 14px;
  align-content: start;
}

.stat-card,
.panel,
.progress-card {
  background: var(--paper);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.7);
  box-shadow: var(--shadow);
}

.stat-card {
  border-radius: var(--radius-lg);
  padding: 18px;
}

.accent-card {
  background: linear-gradient(135deg, rgba(217, 108, 52, 0.22), rgba(255, 250, 241, 0.92));
}

.stat-card span {
  display: block;
  color: var(--muted);
  font-size: 0.92rem;
  margin-bottom: 10px;
}

.stat-card strong {
  font-size: 1.4rem;
}

.main-grid {
  display: grid;
  grid-template-columns: 280px minmax(0, 1.45fr) minmax(300px, 0.9fr);
  gap: 20px;
  margin-top: 24px;
  align-items: start;
}

.module-rail,
.interactive-column,
.content-column {
  display: grid;
  gap: 20px;
}

.rail-header h2,
.module-heading h2,
.panel h3 {
  margin: 0;
}

.rail-header p,
.module-scene,
.pbl-scenario,
.boss-prompt,
.cliffhanger,
.footer-note p,
.flashcard-tip,
.quiz-result {
  color: var(--muted);
  line-height: 1.7;
}

.module-nav {
  display: grid;
  gap: 12px;
}

.tool-shell {
  padding: 18px;
}

.tool-shell-header {
  margin-bottom: 12px;
}

.tool-shell-copy {
  margin: 6px 0 0;
  color: var(--muted);
  line-height: 1.6;
}

.tool-tabs {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  padding: 6px;
  border-radius: 18px;
  background: rgba(239, 228, 209, 0.82);
  border: 1px solid rgba(32, 36, 32, 0.08);
}

.tool-tab {
  border: 1px solid transparent;
  background: transparent;
  border-radius: 14px;
  padding: 11px 10px;
  color: var(--muted);
  cursor: pointer;
  font-weight: 700;
}

.tool-tab.active {
  background: rgba(255, 250, 241, 0.96);
  border-color: rgba(44, 127, 123, 0.18);
  color: var(--ink);
  box-shadow: 0 8px 18px rgba(58, 43, 18, 0.08);
}

.tool-panel {
  display: none;
  margin-top: 16px;
}

.tool-panel.active {
  display: block;
}

.tool-panel h4 {
  margin: 0;
  font-size: 1.08rem;
}

.tool-panel-header {
  margin-bottom: 14px;
}

.cram-card {
  background:
    linear-gradient(180deg, rgba(255, 248, 237, 0.95), rgba(244, 226, 204, 0.92));
}

.guide-panel {
  background:
    linear-gradient(135deg, rgba(44, 127, 123, 0.14), rgba(255, 250, 241, 0.96)),
    linear-gradient(180deg, rgba(255, 255, 255, 0.26), transparent);
}

.guide-message,
.guide-step-desc {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.guide-card {
  margin-top: 16px;
  padding: 18px;
  border-radius: 20px;
  background: rgba(255, 250, 241, 0.92);
  border: 1px solid rgba(44, 127, 123, 0.14);
}

.guide-card h4 {
  margin: 0 0 10px;
  font-size: 1.18rem;
}

.focus-timer {
  font-size: 1.2rem;
  color: var(--accent-deep);
}

.guide-actions {
  margin-top: 18px;
}

.guide-actions .text-btn {
  align-self: center;
}

.micro-progress {
  margin-top: 18px;
}

.micro-progress span {
  display: block;
  margin-bottom: 10px;
  color: var(--muted);
  font-size: 0.92rem;
}

.micro-progress-track {
  height: 10px;
  border-radius: 999px;
  background: rgba(32, 36, 32, 0.08);
  overflow: hidden;
}

.micro-progress-fill {
  width: 0%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), var(--teal));
  transition: width 180ms ease;
}

.cram-status,
.sprint-meta,
#memory-hook,
#final-drill {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.plan-list {
  margin: 16px 0 0;
  padding-left: 20px;
  line-height: 1.8;
}

.plan-list strong {
  color: var(--ink);
}

.module-btn {
  width: 100%;
  padding: 16px;
  border-radius: 20px;
  border: 1px solid var(--line);
  background: rgba(255, 250, 241, 0.78);
  text-align: left;
  cursor: pointer;
}

.module-btn strong,
.module-btn span {
  display: block;
}

.module-btn span {
  color: var(--muted);
  font-size: 0.9rem;
  margin-top: 6px;
}

.module-btn.active {
  background: linear-gradient(135deg, rgba(44, 127, 123, 0.18), rgba(217, 108, 52, 0.18));
  border-color: rgba(44, 127, 123, 0.35);
  transform: translateX(6px);
}

.progress-card,
.panel,
.module-overview {
  border-radius: var(--radius-xl);
  padding: 22px;
}

.module-overview {
  background:
    linear-gradient(135deg, rgba(255, 248, 237, 0.95), rgba(246, 232, 208, 0.92)),
    linear-gradient(180deg, rgba(255, 255, 255, 0.2), transparent);
  border: 1px solid rgba(255, 255, 255, 0.72);
  box-shadow: var(--shadow);
}

.mission-grid,
.two-panel-grid,
.option-grid,
.cram-grid {
  display: grid;
  gap: 14px;
}

.mission-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 18px;
}

.mission-card {
  background: rgba(255, 250, 241, 0.9);
  border: 1px solid rgba(32, 36, 32, 0.08);
  border-radius: var(--radius-md);
  padding: 16px;
}

.mission-card span {
  display: block;
  color: var(--muted);
  font-size: 0.86rem;
  margin-bottom: 10px;
}

.mission-card p {
  margin: 0;
  line-height: 1.65;
}

.accent {
  background: linear-gradient(135deg, rgba(217, 108, 52, 0.2), rgba(255, 250, 241, 0.95));
}

.accent-soft {
  background: linear-gradient(135deg, rgba(183, 141, 46, 0.16), rgba(255, 250, 241, 0.95));
}

.panel {
  position: relative;
}

.panel.tinted,
.boss-panel {
  background:
    linear-gradient(180deg, rgba(255, 250, 241, 0.96), rgba(238, 229, 214, 0.88));
}

.cram-overview-panel {
  background:
    linear-gradient(135deg, rgba(159, 56, 21, 0.08), rgba(255, 250, 241, 0.95)),
    linear-gradient(180deg, rgba(255, 255, 255, 0.3), transparent);
}

.subpanel {
  padding: 18px;
  border-radius: 20px;
  background: rgba(255, 250, 241, 0.88);
  border: 1px solid rgba(32, 36, 32, 0.08);
}

.subpanel.warm {
  background: linear-gradient(135deg, rgba(183, 141, 46, 0.16), rgba(255, 250, 241, 0.9));
}

.subpanel-label {
  margin: 0 0 14px;
  color: var(--accent-deep);
  letter-spacing: 0.08em;
  font-size: 0.84rem;
  font-weight: 700;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 16px;
}

.goal-list,
.check-list,
.step-list {
  margin: 0;
  padding-left: 20px;
  line-height: 1.8;
}

.theory-stack {
  display: grid;
  gap: 14px;
}

.theory-card {
  padding: 16px;
  border-radius: 18px;
  border: 1px solid rgba(44, 127, 123, 0.14);
  background: linear-gradient(135deg, rgba(44, 127, 123, 0.08), rgba(255, 250, 241, 0.92));
}

.theory-card h4,
.checkpoint-box h4,
#example-title,
#pbl-title {
  margin: 0 0 10px;
}

.theory-card p,
.example-answer {
  margin: 0;
  line-height: 1.75;
}

.checkpoint-box,
.decision-box {
  margin-top: 18px;
  padding: 16px;
  border-radius: 18px;
  background: rgba(255, 250, 241, 0.9);
  border: 1px dashed rgba(32, 36, 32, 0.18);
}

.memory-box {
  margin-top: 18px;
  padding: 16px;
  border-radius: 18px;
  background: rgba(44, 127, 123, 0.1);
  border: 1px solid rgba(44, 127, 123, 0.16);
}

.memory-box.warm {
  background: rgba(217, 108, 52, 0.1);
  border-color: rgba(217, 108, 52, 0.16);
}

.memory-box strong {
  display: block;
  margin-bottom: 8px;
}

.spotlight {
  outline: 3px solid rgba(217, 108, 52, 0.35);
  outline-offset: 4px;
  animation: pulse-outline 1.2s ease 2;
}

@keyframes pulse-outline {
  0% {
    outline-color: rgba(217, 108, 52, 0.15);
  }
  50% {
    outline-color: rgba(217, 108, 52, 0.45);
  }
  100% {
    outline-color: rgba(217, 108, 52, 0.15);
  }
}

.option-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 16px;
}

.option-card {
  padding: 14px;
  border-radius: 16px;
  border: 1px solid rgba(32, 36, 32, 0.1);
  background: rgba(255, 250, 241, 0.9);
}

.option-card.good {
  border-color: rgba(44, 127, 123, 0.45);
  background: rgba(44, 127, 123, 0.12);
}

.option-card h4,
.option-card p,
.myth-item p {
  margin: 0;
}

.option-card p,
.myth-item p {
  margin-top: 8px;
  line-height: 1.7;
  color: var(--muted);
}

.myth-list {
  display: grid;
  gap: 14px;
}

.myth-item {
  padding: 16px;
  border-left: 4px solid var(--accent);
  border-radius: 0 18px 18px 0;
  background: rgba(255, 250, 241, 0.82);
}

.myth-item strong {
  display: block;
}

.lab-panel {
  overflow: hidden;
}

.lab-box {
  display: grid;
  gap: 16px;
}

.lab-controls {
  display: grid;
  gap: 14px;
}

.lab-controls label {
  display: grid;
  gap: 8px;
  color: var(--muted);
}

.slider-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 12px;
  align-items: center;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.switch-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.pill-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  background: rgba(255, 250, 241, 0.88);
  border: 1px solid var(--line);
  border-radius: 999px;
}

.lab-output {
  padding: 16px;
  border-radius: 20px;
  background: linear-gradient(135deg, rgba(183, 141, 46, 0.12), rgba(255, 250, 241, 0.92));
  border: 1px solid rgba(183, 141, 46, 0.2);
}

.lab-output strong {
  display: block;
  margin-bottom: 8px;
}

.flashcard {
  width: 100%;
  min-height: 180px;
  padding: 20px;
  border: none;
  border-radius: 22px;
  background:
    linear-gradient(135deg, rgba(44, 127, 123, 0.16), rgba(255, 250, 241, 0.92)),
    linear-gradient(180deg, rgba(255, 255, 255, 0.2), transparent);
  text-align: left;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.48);
}

.flashcard small {
  display: block;
  margin-bottom: 12px;
  color: var(--muted);
}

.flashcard strong {
  display: block;
  font-size: 1.14rem;
  line-height: 1.7;
}

.quiz-form {
  display: grid;
  gap: 16px;
}

.question-card {
  padding: 16px;
  border-radius: 18px;
  background: rgba(255, 250, 241, 0.86);
  border: 1px solid rgba(32, 36, 32, 0.08);
  min-width: 0;
}

.question-card legend {
  padding: 0;
  margin: 0 0 12px;
  font-weight: 600;
}

fieldset.question-card {
  margin: 0;
}

.choice-list {
  display: grid;
  gap: 10px;
}

.choice-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 14px;
  background: rgba(244, 239, 231, 0.9);
}

.quiz-result {
  margin-top: 16px;
}

.quiz-result strong {
  display: block;
  margin-bottom: 8px;
}

.result-good {
  color: var(--teal);
}

.result-warn {
  color: var(--accent-deep);
}

.footer-note {
  margin-top: 22px;
  text-align: center;
}

.result-summary {
  padding: 14px 16px;
  border-radius: 16px;
  background: rgba(255, 250, 241, 0.78);
  border: 1px solid rgba(32, 36, 32, 0.08);
}

body.guided-mode .full-study-only {
  display: none;
}

body.guided-mode .module-overview {
  box-shadow: 0 14px 34px rgba(58, 43, 18, 0.08);
}

@media (min-width: 1280px) {
  .page-shell {
    width: min(1640px, calc(100vw - 40px));
    padding-top: 24px;
  }

  .hero {
    grid-template-columns: minmax(0, 1.55fr) minmax(420px, 0.95fr);
    gap: 26px;
    padding: 34px;
    min-height: 320px;
  }

  .hero-copy {
    display: grid;
    align-content: start;
  }

  .hero h1 {
    max-width: 11ch;
    font-size: clamp(2.6rem, 3.1vw, 4.2rem);
  }

  .hero-panel {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-content: stretch;
  }

  .stat-card {
    min-height: 126px;
    display: grid;
    align-content: start;
  }

  .main-grid {
    grid-template-columns: 300px minmax(720px, 1.5fr) 420px;
    gap: 24px;
    align-items: start;
  }

  .module-rail {
    position: sticky;
    top: 18px;
    align-self: start;
    max-height: calc(100vh - 36px);
    overflow: auto;
    padding-right: 4px;
  }

  .interactive-column {
    position: sticky;
    top: 18px;
    align-self: start;
    max-height: calc(100vh - 36px);
    overflow: auto;
    padding-right: 4px;
  }

  .content-column {
    gap: 24px;
  }

  .guide-panel {
    display: grid;
    grid-template-columns: minmax(0, 1.15fr) minmax(260px, 0.85fr);
    column-gap: 18px;
    row-gap: 14px;
    align-items: start;
  }

  .guide-panel .panel-header,
  .guide-panel .guide-message {
    grid-column: 1 / -1;
  }

  .guide-card {
    margin-top: 0;
    min-height: 100%;
  }

  .micro-progress,
  .guide-actions {
    margin-top: 0;
  }

  .guide-actions {
    align-self: end;
    justify-content: flex-start;
  }

  .cram-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .module-overview {
    padding: 26px;
  }

  .mission-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .module-btn {
    padding: 18px 18px 18px 20px;
    border-radius: 22px;
  }

  .module-btn.active {
    transform: translateX(8px);
  }

  .tool-shell {
    border-radius: 24px;
    padding: 20px;
  }

  .quiz-form {
    gap: 14px;
  }
}

@media (max-width: 1150px) {
  .main-grid {
    grid-template-columns: 1fr;
  }

  .module-rail {
    order: 1;
  }

  .content-column {
    order: 2;
  }

  .interactive-column {
    order: 3;
  }

  .module-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 820px) {
  .page-shell {
    width: min(100vw - 20px, 100%);
    padding-top: 20px;
  }

  .hero {
    grid-template-columns: 1fr;
    padding: 22px;
    border-radius: 28px;
  }

  .mission-grid,
  .two-panel-grid,
  .option-grid,
  .module-nav,
  .tool-tabs {
    grid-template-columns: 1fr;
  }

  .progress-card,
  .panel,
  .module-overview {
    padding: 18px;
    border-radius: 22px;
  }

  .tool-shell {
    padding: 16px;
  }
}