:root {
  --bg: #f0f3f8;
  --surface: #ffffff;
  --sidebar: #1a2332;
  --sidebar-text: #c8d4e8;
  --sidebar-active: #4a7fd4;
  --border: #d4dce8;
  --text: #1a2332;
  --muted: #5a6578;
  --accent: #2d5a9e;
  --accent-soft: #e8eef8;
  --accent-hover: #1e4070;
  --search-hit: #fff3c4;
  --shadow: 0 8px 28px rgba(26, 35, 50, 0.1);
  --radius: 12px;
  --font: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic UI", sans-serif;
  --mono: "SF Mono", "Menlo", "Consolas", monospace;
  --header-h: auto;
  --sidebar-w: 280px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  line-height: 1.65;
}

a {
  color: var(--accent);
}

.app {
  min-height: 100vh;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: linear-gradient(180deg, #1a2332 0%, #243044 100%);
  color: #fff;
  padding: 16px 20px 14px;
  box-shadow: var(--shadow);
}

.header-top {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.menu-btn {
  display: none;
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  font-size: 1.2rem;
  cursor: pointer;
}

.header h1 {
  margin: 0;
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.subtitle {
  margin: 4px 0 0;
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.88rem;
}

.search-bar {
  display: flex;
  gap: 8px;
  margin-top: 14px;
}

.search-bar input {
  flex: 1;
  padding: 10px 14px;
  border: none;
  border-radius: 10px;
  font-size: 0.95rem;
  background: rgba(255, 255, 255, 0.95);
  color: var(--text);
}

.search-bar input:focus {
  outline: 2px solid var(--sidebar-active);
}

.btn-ghost {
  padding: 8px 14px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 8px;
  background: transparent;
  color: #fff;
  cursor: pointer;
  font-size: 0.85rem;
}

.disclaimer {
  margin: 10px 0 0;
  font-size: 0.78rem;
  color: rgba(255, 255, 255, 0.55);
}

/* Layout */
.layout {
  display: flex;
  max-width: 1400px;
  margin: 0 auto;
  min-height: calc(100vh - 120px);
}

.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--sidebar);
  color: var(--sidebar-text);
  overflow-y: auto;
  max-height: calc(100vh - 120px);
  position: sticky;
  top: 120px;
  padding: 12px 0 24px;
}

.sidebar-overlay {
  display: none;
}

.toc {
  padding: 0 8px;
}

.toc-group-label {
  padding: 10px 12px 4px;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: rgba(200, 212, 232, 0.5);
}

.toc a {
  display: block;
  padding: 6px 12px;
  color: var(--sidebar-text);
  text-decoration: none;
  font-size: 0.86rem;
  border-radius: 6px;
  line-height: 1.4;
  border-left: 2px solid transparent;
}

.toc a.level-2 {
  font-weight: 600;
  margin-top: 4px;
  color: #e8eef8;
}

.toc a.level-3 {
  padding-left: 22px;
  font-size: 0.82rem;
  color: rgba(200, 212, 232, 0.85);
}

.toc a:hover {
  background: rgba(255, 255, 255, 0.06);
}

.toc a.active {
  background: rgba(74, 127, 212, 0.2);
  border-left-color: var(--sidebar-active);
  color: #fff;
}

.toc-loading {
  padding: 16px;
  color: var(--sidebar-text);
  font-size: 0.9rem;
}

/* Content */
.content-wrap {
  flex: 1;
  min-width: 0;
  padding: 24px 28px 48px;
}

.content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 40px;
  box-shadow: var(--shadow);
  max-width: 900px;
}

.loading {
  color: var(--muted);
}

/* Markdown */
.markdown-body h1 {
  font-size: 1.6rem;
  margin: 0 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent-soft);
}

.markdown-body h2 {
  font-size: 1.25rem;
  margin: 2.2rem 0 0.8rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
  scroll-margin-top: 140px;
}

.markdown-body h2:first-of-type {
  border-top: none;
  margin-top: 0;
}

.markdown-body h3 {
  font-size: 1.05rem;
  margin: 1.4rem 0 0.6rem;
  color: var(--accent);
  scroll-margin-top: 140px;
}

.markdown-body h4 {
  font-size: 0.95rem;
  margin: 1rem 0 0.4rem;
}

.markdown-body p,
.markdown-body li {
  font-size: 0.95rem;
}

.markdown-body blockquote {
  margin: 1rem 0;
  padding: 12px 16px;
  background: var(--accent-soft);
  border-left: 4px solid var(--accent);
  border-radius: 0 8px 8px 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.markdown-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.88rem;
  display: block;
  overflow-x: auto;
}

.markdown-body th,
.markdown-body td {
  border: 1px solid var(--border);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}

.markdown-body th {
  background: var(--accent-soft);
  font-weight: 600;
  white-space: nowrap;
}

.markdown-body tr:nth-child(even) td {
  background: #f8fafc;
}

.markdown-body code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: #eef2f8;
  padding: 2px 6px;
  border-radius: 4px;
}

.markdown-body pre {
  background: #1a2332;
  color: #e8eef8;
  padding: 16px;
  border-radius: 8px;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.5;
}

.markdown-body pre code {
  background: none;
  padding: 0;
  color: inherit;
}

.markdown-body ul,
.markdown-body ol {
  padding-left: 1.4rem;
}

.markdown-body hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}

.markdown-body .mermaid {
  margin: 1.5rem 0;
  text-align: center;
}

/* Search results */
.search-results {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin-bottom: 16px;
  box-shadow: var(--shadow);
  max-width: 900px;
}

.search-results h2 {
  margin: 0 0 12px;
  font-size: 1rem;
  color: var(--muted);
}

.search-hit {
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
}

.search-hit:last-child {
  border-bottom: none;
}

.search-hit:hover {
  background: var(--accent-soft);
  margin: 0 -12px;
  padding: 10px 12px;
  border-radius: 6px;
}

.search-hit-section {
  font-size: 0.78rem;
  color: var(--accent);
  font-weight: 600;
}

.search-hit-snippet {
  font-size: 0.9rem;
  margin-top: 2px;
}

mark {
  background: var(--search-hit);
  padding: 0 2px;
  border-radius: 2px;
}

/* Back to top */
.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-size: 1.2rem;
  cursor: pointer;
  box-shadow: var(--shadow);
  z-index: 50;
}

.back-top:hover {
  background: var(--accent-hover);
}

/* Mobile */
@media (max-width: 900px) {
  .menu-btn {
    display: block;
  }

  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    max-height: 100vh;
    z-index: 200;
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    padding-top: 16px;
  }

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

  .sidebar-overlay {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    z-index: 150;
  }

  .content-wrap {
    padding: 16px;
  }

  .content {
    padding: 20px 18px;
  }
}