:root {
  --bg-page: #f5efe6;
  --bg-glow: rgba(221, 171, 119, 0.22);
  --surface-panel: rgba(255, 252, 247, 0.92);
  --surface-panel-strong: #fffdfa;
  --surface-card: rgba(255, 255, 255, 0.82);
  --text-primary: #223042;
  --text-secondary: #69778a;
  --text-soft: #8b96a5;
  --border-default: rgba(34, 48, 66, 0.12);
  --border-strong: rgba(34, 48, 66, 0.18);
  --accent-primary: #a54a31;
  --accent-soft: rgba(165, 74, 49, 0.1);
  --accent-warm: #d87a3d;
  --success-soft: rgba(55, 115, 88, 0.12);
  --success-text: #377358;
  --focus-ring: rgba(165, 74, 49, 0.34);
  --shadow-soft: 0 18px 42px rgba(40, 52, 70, 0.08);
  --shadow-card: 0 10px 24px rgba(40, 52, 70, 0.06);
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-7: 28px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text-primary);
  background:
    radial-gradient(circle at top, var(--bg-glow), transparent 32%),
    linear-gradient(180deg, #fbf8f3 0%, var(--bg-page) 55%, #faf6ef 100%);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

button:focus-visible,
select:focus-visible,
a:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--focus-ring);
  outline-offset: 2px;
}

code {
  padding: 0.14rem 0.42rem;
  border-radius: 999px;
  background: #f2ede5;
  color: #5f4b42;
  font-family: "SF Mono", "Menlo", "JetBrains Mono", monospace;
  font-size: 0.86rem;
}

pre {
  overflow: auto;
  padding: var(--space-4);
  border-radius: 18px;
  background: #f4efe8;
  border: 1px solid var(--border-default);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

th,
td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border-default);
  text-align: left;
  vertical-align: top;
}

th {
  color: var(--text-secondary);
  font-weight: 700;
  background: rgba(255, 255, 255, 0.86);
}

.table-wrap {
  overflow: auto;
  border-radius: 18px;
  border: 1px solid var(--border-default);
  background: rgba(255, 255, 255, 0.72);
}

.app-shell {
  max-width: 1480px;
  margin: 0 auto;
  padding: var(--space-4);
}

.topbar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-4);
  padding: 14px 18px;
  border: 1px solid var(--border-default);
  border-radius: 999px;
  background: rgba(255, 252, 247, 0.78);
  box-shadow: var(--shadow-card);
  backdrop-filter: blur(10px);
}

.brand {
  display: grid;
  gap: 2px;
}

.brand strong {
  font-size: 1rem;
}

.brand span {
  color: var(--text-secondary);
  font-size: 0.88rem;
}

.topbar-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.pill-link,
.nav-button {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid var(--border-default);
  background: rgba(255, 255, 255, 0.74);
  color: var(--text-secondary);
}

.pill-link.is-active,
.nav-button.is-active,
.pill-link:hover,
.nav-button:hover {
  border-color: rgba(165, 74, 49, 0.24);
  background: var(--accent-soft);
  color: var(--accent-primary);
}

.hero {
  position: relative;
  overflow: hidden;
  padding: var(--space-8);
  border-radius: 28px;
  border: 1px solid var(--border-default);
  background: linear-gradient(135deg, rgba(255, 253, 250, 0.98), rgba(255, 248, 240, 0.86));
  box-shadow: var(--shadow-soft);
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto -40px -80px auto;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(216, 122, 61, 0.18), transparent 68%);
  pointer-events: none;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 8px 12px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-primary);
  font-size: 0.84rem;
  font-weight: 700;
}

.hero h1,
.page-title {
  margin: 14px 0 12px;
  font-size: clamp(2rem, 4vw, 3.4rem);
  line-height: 1.05;
}

.hero p,
.page-subtitle {
  margin: 0;
  max-width: 780px;
  color: var(--text-secondary);
  font-size: 1rem;
}

.hero-meta,
.stat-grid,
.card-grid,
.module-grid,
.asset-grid,
.content-grid,
.question-grid {
  display: grid;
  gap: var(--space-4);
}

.hero-meta {
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  margin-top: var(--space-6);
}

.stat-card,
.module-card,
.panel,
.content-nav,
.filter-panel,
.question-card,
.asset-card,
.highlight-card {
  border-radius: 24px;
  border: 1px solid var(--border-default);
  background: var(--surface-panel);
  box-shadow: var(--shadow-card);
}

.stat-card,
.asset-card,
.highlight-card {
  padding: var(--space-5);
}

.stat-card strong,
.asset-card strong {
  display: block;
  font-size: 1.5rem;
  line-height: 1.1;
}

.muted {
  color: var(--text-secondary);
}

.soft {
  color: var(--text-soft);
}

.home-section,
.page-section {
  margin-top: var(--space-8);
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  justify-content: space-between;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.section-head h2 {
  margin: 0;
  font-size: 1.42rem;
  line-height: 1.2;
}

.module-grid {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.module-card {
  display: grid;
  gap: var(--space-4);
  padding: var(--space-6);
  transition: transform 220ms ease, border-color 220ms ease, background-color 220ms ease;
}

.module-card:hover {
  transform: translateY(-3px);
  border-color: rgba(165, 74, 49, 0.24);
}

.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.chip {
  display: inline-flex;
  align-items: center;
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(34, 48, 66, 0.06);
  color: var(--text-secondary);
  font-size: 0.82rem;
}

.chip.accent {
  background: var(--accent-soft);
  color: var(--accent-primary);
}

.chip.success {
  background: var(--success-soft);
  color: var(--success-text);
}

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.action-link,
.ghost-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 42px;
  padding: 10px 14px;
  border-radius: 14px;
  border: 1px solid rgba(165, 74, 49, 0.18);
}

.action-link {
  background: rgba(165, 74, 49, 0.08);
  color: var(--accent-primary);
  font-weight: 600;
}

.ghost-link {
  background: rgba(255, 255, 255, 0.72);
  color: var(--text-secondary);
}

.button-link[disabled] {
  cursor: default;
  opacity: 0.45;
}

.overview-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-6);
}

.panel {
  padding: var(--space-6);
}

.panel h3 {
  margin: 0 0 var(--space-3);
  font-size: 1.08rem;
  line-height: 1.25;
}

.panel p {
  margin: 0;
  color: var(--text-secondary);
}

.content-grid {
  grid-template-columns: minmax(250px, 300px) minmax(0, 1fr);
  align-items: start;
}

.content-nav {
  position: sticky;
  top: var(--space-4);
  padding: var(--space-4);
  max-height: calc(100vh - 32px);
  overflow: auto;
}

.content-nav h3,
.filter-panel h3 {
  margin: 0 0 var(--space-3);
  font-size: 1rem;
}

.nav-list,
.inline-list {
  display: grid;
  gap: var(--space-2);
}

.content-link {
  display: block;
  padding: 12px 14px;
  border-radius: 16px;
  border: 1px solid transparent;
  background: rgba(255, 255, 255, 0.72);
}

.content-link.is-active,
.content-link:hover {
  border-color: rgba(165, 74, 49, 0.24);
  background: var(--accent-soft);
}

.content-reader {
  display: grid;
  gap: var(--space-4);
}

.reader-section {
  padding: var(--space-6);
  border-radius: 24px;
  border: 1px solid var(--border-default);
  background: var(--surface-panel);
  box-shadow: var(--shadow-card);
  scroll-margin-top: var(--space-6);
}

.reader-section h2 {
  margin: 0 0 var(--space-3);
  font-size: 1.26rem;
}

.reader-prose h2,
.reader-prose h3,
.reader-prose h4,
.reader-prose h5 {
  margin: 18px 0 10px;
  line-height: 1.3;
}

.reader-prose h3,
.reader-prose h4 {
  color: var(--accent-primary);
}

.reader-prose p,
.reader-prose ul,
.reader-prose ol,
.reader-prose .table-wrap,
.reader-prose pre {
  margin: 12px 0;
}

.reader-prose ul,
.reader-prose ol {
  padding-left: 20px;
}

.reader-prose hr {
  height: 1px;
  margin: 20px 0;
  border: 0;
  background: linear-gradient(90deg, rgba(165, 74, 49, 0.25), rgba(34, 48, 66, 0.04));
}

.question-grid {
  grid-template-columns: minmax(250px, 280px) minmax(0, 1fr);
  align-items: start;
}

.filter-panel {
  position: sticky;
  top: var(--space-4);
  padding: var(--space-5);
}

.filter-group {
  display: grid;
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.filter-group label {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.filter-group select {
  width: 100%;
  min-height: 42px;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px solid var(--border-default);
  background: var(--surface-panel-strong);
  color: var(--text-primary);
}

.question-list {
  display: grid;
  gap: var(--space-4);
}

.question-card {
  overflow: hidden;
  max-width: 760px;
}

.question-body {
  padding: 0 var(--space-5) var(--space-5);
}

.question-body--card {
  padding-top: var(--space-5);
}

.question-body ol,
.question-body ul {
  padding-left: 22px;
}

.question-body p {
  margin: 10px 0;
}

.question-title {
  margin: 10px 0 0;
  font-size: 1rem;
}

.question-progress {
  display: grid;
  gap: 10px;
  margin-bottom: var(--space-4);
}

.question-progress-text {
  color: var(--text-secondary);
  font-size: 0.92rem;
  font-weight: 600;
}

.question-progress-bar {
  height: 8px;
  border-radius: 999px;
  background: rgba(34, 48, 66, 0.08);
  overflow: hidden;
}

.question-progress-bar span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent-primary), var(--accent-warm));
}

.option-list {
  display: grid;
  gap: var(--space-3);
  margin-top: var(--space-4);
}

.option-button {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: var(--space-3);
  align-items: start;
  width: 100%;
  padding: 14px 16px;
  border-radius: 18px;
  border: 1px solid var(--border-default);
  background: rgba(255, 255, 255, 0.76);
  color: var(--text-primary);
  text-align: left;
}

.option-button:hover,
.option-button.is-selected {
  border-color: rgba(165, 74, 49, 0.3);
  background: var(--accent-soft);
}

.option-key {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 999px;
  background: rgba(34, 48, 66, 0.08);
  color: var(--text-secondary);
  font-weight: 700;
}

.question-hint {
  margin-top: var(--space-4);
}

.question-actions {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-3);
  margin-top: var(--space-5);
}

.answer-box {
  margin-top: var(--space-4);
  padding: var(--space-4);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.74);
  border: 1px solid var(--border-default);
}

.flashcard-stage {
  display: grid;
  gap: var(--space-4);
  justify-items: center;
}

.flashcard {
  position: relative;
  min-height: 360px;
  transform-style: preserve-3d;
}

.flashcard--single {
  width: min(100%, 760px);
  min-height: 440px;
}

.flashcard-face {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-3);
  width: 100%;
  height: 100%;
  padding: var(--space-6);
  border-radius: 24px;
  border: 1px solid var(--border-default);
  background: linear-gradient(180deg, rgba(255, 253, 250, 0.98), rgba(247, 240, 231, 0.92));
  box-shadow: var(--shadow-card);
  color: var(--text-primary);
  text-align: left;
  backface-visibility: hidden;
  transition: transform 220ms ease;
  overflow: auto;
}

.flashcard-front {
  transform: rotateY(0deg);
}

.flashcard-back {
  transform: rotateY(180deg);
  background: rgba(255, 255, 255, 0.95);
}

.flashcard.is-flipped .flashcard-front {
  transform: rotateY(180deg);
}

.flashcard.is-flipped .flashcard-back {
  transform: rotateY(360deg);
}

.flashcard h2 {
  margin: 0;
  font-size: 1.18rem;
  line-height: 1.3;
}

.flashcard p {
  margin: 0;
  color: var(--text-secondary);
}

.flashcard-label {
  display: inline-flex;
  align-items: center;
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-primary);
  font-size: 0.82rem;
  font-weight: 700;
}

.asset-grid {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin-top: var(--space-4);
}

.asset-metrics,
.status-stack {
  display: grid;
  gap: var(--space-3);
}

.status-item {
  display: flex;
  justify-content: space-between;
  gap: var(--space-3);
  padding: 12px 14px;
  border-radius: 16px;
  border: 1px solid var(--border-default);
  background: rgba(255, 255, 255, 0.72);
}

.media-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-4);
}

.media-card {
  overflow: hidden;
  border-radius: 22px;
  border: 1px solid var(--border-default);
  background: rgba(255, 255, 255, 0.78);
  box-shadow: var(--shadow-card);
}

.media-card img {
  display: block;
  width: 100%;
  height: 200px;
  object-fit: cover;
  background: #fff8ef;
}

.media-card .caption {
  padding: 14px 16px;
  color: var(--text-secondary);
}

.empty-state {
  padding: var(--space-6);
  border-radius: 24px;
  border: 1px dashed var(--border-strong);
  background: rgba(255, 255, 255, 0.52);
  color: var(--text-secondary);
}

@media (max-width: 1100px) {
  .overview-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .content-grid,
  .question-grid {
    grid-template-columns: 1fr;
  }

  .content-nav,
  .filter-panel {
    position: static;
    max-height: none;
  }
}

@media (max-width: 720px) {
  .app-shell {
    padding: 12px;
  }

  .hero,
  .panel,
  .module-card,
  .reader-section,
  .filter-panel,
  .content-nav {
    padding: var(--space-5);
    border-radius: 22px;
  }

  .overview-grid {
    grid-template-columns: 1fr;
  }

  .topbar {
    border-radius: 24px;
  }

  .question-actions {
    grid-template-columns: 1fr;
  }
}