:root {
  --bg: #333;
  --bg-secondary: #3c3c3c;
  --bg-code: #2a2a2a;
  --text: #ccc;
  --text-bright: white;
  --text-muted: #999;
  --text-code: #b0b0b0;
  --text-inline-code: plum;
  --border: #555;
  --border-code: #3a3a3a;
  --link: palegoldenrod;
  --heading: lightskyblue;
  --heading-link: #f0c090;
  --header-nav-link: pink;
  --emphasis: pink;
  --nav-section: #bbb;
  --nav-section-active: #ddd;
  --content-width: 900px;
  --sidebar-width: 280px;
  --header-height: 48px;
  --line-height: 1.6;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  line-height: var(--line-height);
}

a {
  color: var(--link);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  padding: 0 16px;
  gap: 24px;
}

.header-title {
  color: var(--text);
  font-weight: bold;
  font-size: 1.1rem;
  white-space: nowrap;
}

.header-title:hover {
  text-decoration: none;
  color: var(--text-bright);
}

.header-spacer {
  flex: 1;
}

.header-nav {
  display: flex;
  gap: 16px;
}

.header-nav a {
  display: flex;
  align-items: center;
  gap: 4px;
  color: var(--header-nav-link);
  font-size: 0.9rem;
}

.header-nav a svg {
  flex-shrink: 0;
  opacity: 0.85;
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 2px;
}

.lang-selector {
  position: relative;
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  background: none;
  border: none;
  color: var(--text);
  padding: 4px 6px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.85rem;
  opacity: 0.8;
}

.lang-btn:hover {
  opacity: 1;
}

.lang-popup {
  display: none;
  position: absolute;
  right: 0;
  top: 100%;
  margin-top: 4px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 4px;
  list-style: none;
  min-width: 60px;
  z-index: 200;
}

.lang-popup.open {
  display: block;
}

.lang-popup li a {
  display: block;
  padding: 6px 12px;
  color: var(--text);
  font-size: 0.85rem;
}

.lang-popup li a:hover {
  background: var(--bg);
  text-decoration: none;
}

.sidebar-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 1.2rem;
  cursor: pointer;
  padding: 4px 8px;
}

/* Draft banner */
.draft-banner {
  position: fixed;
  top: var(--header-height);
  right: 0;
  background: #c44;
  color: white;
  padding: 4px 16px;
  font-size: 0.75rem;
  font-weight: bold;
  letter-spacing: 0.1em;
  z-index: 99;
}

/* Layout */
.layout {
  margin-top: var(--header-height);
  display: grid;
  grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
  min-height: calc(100vh - var(--header-height));
}

.layout.no-sidebar {
  grid-template-columns: 1fr;
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-width);
  flex-shrink: 0;
  padding: 24px 16px;
  border-right: 1px solid var(--bg-secondary);
  position: sticky;
  top: var(--header-height);
  height: calc(100vh - var(--header-height));
  overflow-y: auto;
}

.nav-section {
  margin-bottom: 16px;
}

.nav-section-title {
  color: var(--nav-section);
  font-weight: bold;
  font-size: 1.0rem;
  display: block;
  margin-bottom: 8px;
}

.nav-section-title.active {
  color: var(--nav-section-active);
}

.nav-list {
  list-style: none;
  padding-left: 8px;
}

.nav-list li {
  margin-bottom: 4px;
}

.nav-list li a {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.nav-list li a:hover {
  color: var(--text);
}

.nav-list li a.active {
  color: var(--emphasis);
  font-weight: bold;
}

/* Content */
.content {
  min-width: 0;
  max-width: var(--content-width);
  padding: 32px 24px;
  overflow-wrap: break-word;
}

.content.portal {
  max-width: var(--content-width);
  padding: 48px 24px;
  margin: 0 auto;
}

.content article h1 {
  font-size: 1.8rem;
  margin-bottom: 24px;
  color: var(--heading);
}

.content article h2 {
  font-size: 1.4rem;
  margin-top: 32px;
  margin-bottom: 16px;
  color: var(--heading-link);
}

.content article h3 {
  font-size: 1.1rem;
  margin-top: 24px;
  margin-bottom: 12px;
  color: var(--text);
}

.content article p {
  margin-bottom: 12px;
}

.content article ul,
.content article ol {
  margin-bottom: 12px;
  padding-left: 24px;
}

.content article li {
  margin-bottom: 4px;
}

.content article strong {
  color: var(--emphasis);
}

.content article code {
  background: var(--bg-code);
  color: var(--text-inline-code);
  padding: 2px 6px;
  border-radius: 3px;
  font-size: 0.9em;
}

.content article pre {
  background: var(--bg-code) !important;
  color: var(--text-code);
  padding: 16px;
  border-radius: 4px;
  overflow-x: auto;
  margin-bottom: 16px;
  border: 1px solid var(--border-code);
}

.content article pre code {
  background: none;
  padding: 0;
}

.content article table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 16px;
}

.content article th,
.content article td {
  border: 1px solid var(--bg-secondary);
  padding: 8px 12px;
  text-align: left;
}

.content article th {
  background: var(--bg-secondary);
}

.content article blockquote {
  border-left: 3px solid var(--text-muted);
  padding-left: 16px;
  margin-bottom: 12px;
  color: var(--text-muted);
}

/* Footer */
.footer {
  padding: 12px 16px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.8rem;
  border-top: 1px solid var(--bg-secondary);
}

/* Responsive */
@media (max-width: 768px) {
  .layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .sidebar {
    position: fixed;
    left: calc(-1 * var(--sidebar-width));
    width: var(--sidebar-width);
    top: var(--header-height);
    height: calc(100vh - var(--header-height));
    background: var(--bg);
    z-index: 50;
    transition: left 0.2s ease;
    border-right: 1px solid var(--border);
  }

  .sidebar.open {
    left: 0;
  }

  .sidebar-toggle {
    display: block;
  }

  .content {
    padding: 24px 16px;
  }
}

@media (max-width: 480px) {
  :root {
    --header-height: 44px;
  }

  .header-inner {
    padding: 0 12px;
    gap: 12px;
  }

  .header-nav a {
    font-size: 0.8rem;
  }

  .content article h1 {
    font-size: 1.4rem;
  }

  .content article h2 {
    font-size: 1.2rem;
  }
}

/* Light mode */
[data-theme="light"] {
  --bg: #f5f5f5;
  --bg-secondary: #e8e8e8;
  --bg-code: #eee;
  --text: #333;
  --text-bright: #000;
  --text-muted: #666;
  --text-code: #333;
  --text-inline-code: #8b5ca0;
  --border: #ccc;
  --border-code: #ddd;
  --link: #b8860b;
  --heading: #2a6496;
  --heading-link: #c06020;
  --header-nav-link: #c04060;
  --emphasis: #c04060;
  --nav-section: #666;
  --nav-section-active: #333;
}

/* Code block theme switching */
.code-light { display: none; }
.code-dark { display: block; }

[data-theme="light"] .code-light { display: block; }
[data-theme="light"] .code-dark { display: none; }

/* Theme toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  color: var(--text);
  padding: 5px 6px;
  border-radius: 4px;
  cursor: pointer;
  opacity: 0.8;
}

.theme-toggle:hover {
  opacity: 1;
}