/* 练习子站：与 docs 讲义共用 style.css 变量 */

/* ---- 练习首页：左栏目录 + 右栏模块（美化版） ---- */
.practice-index-body {
  min-height: 100vh;
}

.practice-index-shell .book-sidebar {
  background: linear-gradient(180deg, #f0f3f5 0%, #e8ecef 100%);
  border-right: 0;
  box-shadow: inset -1px 0 0 rgba(0, 0, 0, 0.06);
  padding: 0;
}

.practice-index-shell .book-main {
  background:
    radial-gradient(ellipse 80% 50% at 100% 0%, rgba(13, 148, 136, 0.07), transparent 55%),
    radial-gradient(ellipse 60% 40% at 0% 100%, rgba(26, 26, 46, 0.04), transparent 50%),
    var(--paper);
  padding: 36px 40px 48px;
}

.practice-index-brand-block {
  padding: 22px 20px 18px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  background: rgba(255, 255, 255, 0.45);
  backdrop-filter: blur(8px);
}

.practice-index-brand {
  display: block;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--accent);
  text-decoration: none !important;
  line-height: 1.35;
  transition: color 0.2s ease;
}

.practice-index-brand:hover {
  color: var(--accent-hover);
}

.practice-index-side-kicker {
  margin: 10px 0 0;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

.practice-index-nav-wrap {
  padding: 16px 12px 24px;
}

.practice-index-nav {
  list-style: none;
  margin: 0;
  padding: 0;
}

.practice-index-nav-link {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 12px 14px;
  margin: 4px 0;
  border-radius: 12px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--ink-light);
  text-decoration: none !important;
  border: 1px solid transparent;
  transition:
    background 0.2s ease,
    border-color 0.2s ease,
    box-shadow 0.2s ease,
    color 0.2s ease;
}

.practice-index-nav-link:hover {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.75);
  border-color: rgba(13, 148, 136, 0.2);
  box-shadow: 0 4px 14px rgba(13, 148, 136, 0.08);
}

.practice-index-nav-link .pin-num {
  flex-shrink: 0;
  min-width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 800;
  color: #fff;
  background: linear-gradient(145deg, var(--accent) 0%, #0a7c73 100%);
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(13, 148, 136, 0.35);
}

.practice-index-nav-link .pin-text {
  padding-top: 3px;
  font-weight: 500;
}

/* 右侧主区 */
.practice-index-hero {
  margin-bottom: 28px;
}

.practice-index-eyebrow {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 8px;
  opacity: 0.9;
}

.practice-index-title {
  font-family: "DM Sans", var(--font-sans);
  font-size: clamp(2.25rem, 4vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  color: var(--ink);
  margin: 0;
  line-height: 1.1;
}

.practice-index-title-rule {
  width: 48px;
  height: 4px;
  margin-top: 16px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--accent), rgba(13, 148, 136, 0.25));
}

.practice-index-main .practice-modules {
  display: grid;
  gap: 18px;
  max-width: 38rem;
}

.practice-module-card {
  position: relative;
  display: block;
  border-radius: 16px;
  text-decoration: none !important;
  color: inherit;
  overflow: hidden;
  border: 1px solid rgba(231, 229, 228, 0.95);
  background: var(--paper-elevated);
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.04),
    0 12px 40px rgba(26, 26, 46, 0.06);
  transition:
    transform 0.25s ease,
    box-shadow 0.25s ease,
    border-color 0.25s ease;
}

.practice-module-card:hover {
  transform: translateY(-3px);
  border-color: rgba(13, 148, 136, 0.35);
  box-shadow:
    0 4px 12px rgba(13, 148, 136, 0.12),
    0 24px 48px rgba(26, 26, 46, 0.1);
}

.practice-module-card .pm-accent {
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 5px;
  background: linear-gradient(180deg, var(--accent) 0%, #0a7c73 100%);
  border-radius: 16px 0 0 16px;
}

.practice-module-card .pm-inner {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 22px 24px 22px 26px;
}

.practice-module-card .pm-badge {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: "DM Sans", var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  color: var(--accent);
  background: rgba(13, 148, 136, 0.1);
  border-radius: 12px;
  border: 1px solid rgba(13, 148, 136, 0.18);
}

.practice-module-card .pm-copy {
  flex: 1;
  min-width: 0;
}

.practice-module-card .pm-tit {
  font-size: 16px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 0 0 8px;
  line-height: 1.35;
}

.practice-module-card .pm-desc {
  font-size: 13px;
  color: var(--ink-light);
  line-height: 1.6;
  margin: 0;
}

.practice-module-card .pm-arrow {
  flex-shrink: 0;
  font-size: 18px;
  color: var(--ink-muted);
  opacity: 0.5;
  transition: transform 0.25s ease, opacity 0.25s ease, color 0.25s ease;
}

.practice-module-card:hover .pm-arrow {
  transform: translateX(4px);
  opacity: 1;
  color: var(--accent);
}

@media (max-width: 980px) {
  .practice-index-shell .book-main {
    padding: 24px 18px 36px;
  }

  .practice-module-card .pm-inner {
    flex-wrap: wrap;
    padding: 18px 18px 18px 22px;
  }

  .practice-module-card .pm-arrow {
    width: 100%;
    text-align: right;
    margin-top: -8px;
  }
}

/* 单篇练习页 */
.book-shell.practice-page {
  grid-template-columns: 300px 1fr;
}

.practice-page .toc-scroll {
  padding: 12px 18px;
  overflow: visible;
  max-height: none;
}

.practice-page .toc__title {
  font-weight: 700;
  color: var(--ink);
  font-size: 13px;
  padding: 10px 0;
  margin: 0 0 10px;
  border-bottom: 1px solid var(--border);
}

.practice-page .toc a {
  color: var(--ink);
  text-decoration: none !important;
}

.practice-page .toc a:hover {
  color: var(--accent-hover);
}

.practice-page .toc ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.practice-page .toc .lv1 {
  display: block;
  padding: 6px 0 4px;
  font-weight: 700;
  font-size: 14px;
}

.practice-page .toc .lv2 {
  margin: 4px 0 12px 12px;
  padding-left: 12px;
  border-left: 2px solid rgba(231, 229, 228, 0.95);
  display: grid;
  gap: 2px;
}

.practice-page .toc .lv2 a {
  display: flex;
  gap: 8px;
  padding: 5px 0;
  color: var(--ink-light);
  font-size: 12px;
}

.practice-page .toc .lv2 .n {
  color: var(--ink-muted);
  font-weight: 800;
  min-width: 22px;
}

.practice-page .toc a.is-active {
  color: var(--accent-hover);
  font-weight: 700;
}

.practice-breadcrumb {
  font-size: 13px;
  color: var(--ink-muted);
  margin-bottom: 10px;
}

.practice-breadcrumb a {
  color: var(--accent);
}

.practice-breadcrumb .sep {
  margin: 0 6px;
  color: var(--border);
}

.practice-footer-note {
  margin-top: 28px;
  padding-top: 18px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--ink-muted);
  line-height: 1.6;
}

/* 分子进化练习页：Mermaid 思维导图 + 树图 */
.mermaid-figure {
  margin: 1rem 0;
  padding: 12px 8px;
  overflow-x: auto;
  background: rgba(0, 0, 0, 0.02);
  border-radius: 10px;
  border: 1px solid var(--border);
}

.mermaid-figure .mermaid {
  display: flex;
  justify-content: center;
  min-height: 420px;
}

.mermaid-figure svg {
  max-width: 100%;
  height: auto;
}

.practice-figure {
  margin: 1rem 0;
}

.practice-figure img {
  display: block;
  max-width: 100%;
  height: auto;
}

.practice-figure--half img {
  max-width: 75%;
  margin-left: auto;
  margin-right: auto;
}

.practice-figure figcaption {
  margin-top: 10px;
  font-size: 13px;
  color: var(--ink-muted);
  line-height: 1.5;
}

.r-tree-steps {
  margin-top: 1rem;
}

@media (max-width: 980px) {
  .book-shell.practice-page {
    grid-template-columns: 1fr;
  }
}