/* 练习页：与 docs 讲义风格统一 */
.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-lead {
  color: var(--ink-light);
  max-width: 52em;
  margin-bottom: 22px;
  line-height: 1.75;
}

.exercise {
  border: 0;
  border-radius: 0;
  padding: 0;
  margin: 26px 0 18px;
  background: transparent;
  scroll-margin-top: 20px;
}
.exercise .ex-kicker { display: none; }
.exercise h2 {
  font-size: 18px;
  font-weight: 800;
  margin: 0 0 10px;
  color: var(--ink);
}
.exercise .goal {
  font-size: 13px;
  color: var(--ink-muted);
  margin-bottom: 14px;
  line-height: 1.6;
}
.exercise ol.tasks,
.exercise ul.tasks {
  margin: 0 0 14px 1.2em;
  padding: 0;
  color: var(--ink-light);
  line-height: 1.65;
}
.exercise ol.tasks li,
.exercise ul.tasks li { margin: 8px 0; }
.exercise .starter-label {
  font-size: 13px;
  font-weight: 800;
  color: var(--ink);
  margin: 12px 0 6px;
}

details.ex-answer {
  margin-top: 14px;
  border-top: 1px dashed var(--border);
  padding-top: 14px;
}
details.ex-answer summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--accent-hover);
  font-size: 13px;
  list-style-position: outside;
}
details.ex-answer summary::-webkit-details-marker { color: var(--accent); }
details.ex-answer[open] summary { margin-bottom: 10px; }

.book-main kbd {
  font-family: ui-monospace, monospace;
  font-size: 0.88em;
  padding: 0.12em 0.45em;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #f4f4f5;
  color: var(--ink);
}

.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;
}

.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  border: 1px solid #e5e5e5;
  background: #fff;
  color: var(--ink);
  border-radius: 6px;
  padding: 4px 8px;
  font-size: 12px;
  cursor: pointer;
}
.copy-btn:hover { background: #f7f7f7; }
.copy-btn[data-state="ok"] {
  border-color: rgba(13, 148, 136, 0.35);
  color: var(--accent-hover);
}

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