:root {
  --bg: #f3f5f7;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --line: #e5e7eb;
  --primary: #0f766e;
  --primary-soft: #ccfbf1;
  --code-bg: #111827;
  --code-text: #e5e7eb;
  --shadow: 0 12px 30px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: radial-gradient(circle at 10% 0%, #ecfeff 0%, var(--bg) 42%), var(--bg);
  color: var(--text);
  line-height: 1.7;
}

.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  z-index: 1000;
  background: linear-gradient(90deg, #0ea5e9, var(--primary));
  transition: width 0.15s ease;
}

.mobile-menu-btn {
  display: none;
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 1200;
  border: 0;
  border-radius: 999px;
  padding: 10px 14px;
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  box-shadow: var(--shadow);
}

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: 290px;
  height: 100vh;
  padding: 22px 16px;
  border-right: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(6px);
  overflow: auto;
}

.sidebar-header h1 {
  margin: 0;
  font-size: 1.2rem;
  color: #0f172a;
}

.sidebar-header p {
  margin: 2px 0 12px;
  color: var(--muted);
  font-size: 0.92rem;
}

.search-box {
  margin-bottom: 12px;
}

.search-box input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
  color: var(--text);
  outline: none;
}

.search-box input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-soft);
}

.toc {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.toc-link {
  text-decoration: none;
  color: #334155;
  font-size: 0.95rem;
  border-radius: 8px;
  padding: 8px 10px;
  transition: all 0.2s ease;
}

.toc-link:hover {
  background: #f1f5f9;
}

.toc-link.active {
  color: #042f2e;
  background: var(--primary-soft);
  font-weight: 700;
}

.content {
  margin-left: 290px;
  padding: 28px;
  max-width: 1000px;
}

.section {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: var(--shadow);
  padding: 24px;
  margin-bottom: 20px;
}

.section h2 {
  margin-top: 0;
  color: #0f172a;
  border-bottom: 1px solid var(--line);
  padding-bottom: 10px;
}

.section h3 {
  margin-top: 20px;
  margin-bottom: 8px;
  color: #134e4a;
}

.section p,
.section li {
  color: #1e293b;
}

.section code {
  background: #f1f5f9;
  padding: 2px 6px;
  border-radius: 5px;
  font-family: "Consolas", "SFMono-Regular", monospace;
  font-size: 0.92em;
}

pre {
  margin: 8px 0 14px;
  border-radius: 12px;
  overflow: auto;
  border: 1px solid #1f2937;
  background: var(--code-bg);
}

pre code {
  display: block;
  padding: 14px;
  color: var(--code-text);
  background: transparent;
  white-space: pre;
}

.note {
  border-left: 4px solid var(--primary);
  border-radius: 8px;
  background: #f0fdfa;
  padding: 10px 12px;
  color: #134e4a;
}

mark {
  background: #fef08a;
  color: inherit;
}

@media (max-width: 900px) {
  .mobile-menu-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .sidebar {
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    z-index: 1100;
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .content {
    margin-left: 0;
    padding: 16px;
  }

  .section {
    padding: 18px;
  }
}