/* Light theme (default) */
:root {
  --bg: #ffffff;
  --panel: #f8f9fa;
  --text: #1a1a1a;
  --muted: #666666;
  --link: #2c5aa0;
  --brand: #2c5aa0;
  --accent: #16a34a;
  --border: #e0e0e0;
  --card-bg: #ffffff;
  --card-border: #e0e0e0;
  --input-bg: #ffffff;
  --input-border: #d0d0d0;
}

/* Dark theme */
[data-theme="dark"] {
  --bg: #0b1220;
  --panel: #111a2b;
  --text: #e7eefb;
  --muted: #9eb0d1;
  --link: #7db2ff;
  --brand: #5a8dee;
  --accent: #16a34a;
  --border: #1b2740;
  --card-bg: #0b1529;
  --card-border: #162544;
  --input-bg: #0a1324;
  --input-border: #1c2a4a;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, system-ui, -apple-system, 'Segoe UI', Roboto, Ubuntu, Cantarell, 'Noto Sans', sans-serif;
  line-height: 1.55;
  transition: background-color 0.3s ease, color 0.3s ease;
}

a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  text-decoration: underline;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 18px;
}

.site-header {
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.header-inner {
  display: flex;
  gap: 16px;
  align-items: center;
  flex-wrap: wrap;
}

.brand {
  font-weight: 700;
  color: var(--text);
  font-size: 20px;
  margin-right: auto;
}

.nav {
  display: flex;
  gap: 4px;
}

.nav a {
  padding: 8px 12px;
  color: var(--muted);
  border-radius: 6px;
  transition: background-color 0.2s, color 0.2s;
}

.nav a:hover {
  background: var(--bg);
  color: var(--text);
  text-decoration: none;
}

.search {
  display: flex;
  gap: 8px;
}

.search input {
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 6px;
  transition: border-color 0.2s;
}

.search input:focus {
  outline: none;
  border-color: var(--brand);
}

.search button {
  background: var(--brand);
  border: 0;
  color: #fff;
  padding: 8px 16px;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 600;
  transition: background-color 0.2s;
}

.search button:hover {
  background: #234a8a;
}

/* Theme Toggle Button */
.theme-toggle {
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 18px;
  transition: background-color 0.2s, transform 0.2s;
}

.theme-toggle:hover {
  background: var(--card-bg);
  transform: scale(1.1);
}

.hero {
  padding: 40px 0;
  text-align: center;
}

.hero h1 {
  margin: 0 0 15px 0;
  font-size: 42px;
  color: var(--text);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 16px;
  margin: 20px 0;
}

.card {
  display: block;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 16px;
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.card-title {
  font-weight: 700;
  color: var(--text);
  font-size: 16px;
  margin-bottom: 4px;
}

.card-desc {
  color: var(--muted);
  font-size: 14px;
}

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

.list li {
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}

.list li:last-child {
  border-bottom: none;
}

.pagination {
  margin-top: 20px;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.pagination a, .pagination .current {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  padding: 8px 12px;
  transition: background-color 0.2s;
}

.pagination a:hover {
  background: var(--panel);
  text-decoration: none;
}

.pagination .current {
  background: var(--brand);
  color: #fff;
  border-color: var(--brand);
}

.prose {
  line-height: 1.7;
}

.prose p {
  margin: 15px 0;
}

.button {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 10px 16px;
  border-radius: 8px;
  font-weight: 600;
  transition: background-color 0.2s;
}

.button:hover {
  background: #138f3f;
  text-decoration: none;
}

.notice {
  background: var(--panel);
  border: 1px solid var(--border);
  padding: 15px;
  border-radius: 8px;
  margin: 20px 0;
}

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--panel);
  margin-top: 60px;
  padding: 20px 0;
}

.site-footer p {
  color: var(--muted);
  text-align: center;
  margin: 0;
}

.site-footer a {
  color: var(--link);
  margin: 0 8px;
}

.langbar {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  margin: 20px 0;
  padding: 15px;
  background: var(--panel);
  border-radius: 8px;
}

.langbar a {
  display: inline-block;
  transition: transform 0.2s;
}

.langbar a:hover {
  transform: scale(1.1);
}

.langbar img {
  border: 1px solid var(--border);
  border-radius: 3px;
  width: 25px;
  height: 17px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

article {
  max-width: 900px;
  margin: 0 auto;
}

article h1 {
  color: var(--text);
  border-bottom: 2px solid var(--border);
  padding-bottom: 15px;
  margin-bottom: 20px;
}

article h2 {
  color: var(--text);
  margin-top: 40px;
  margin-bottom: 20px;
}

article h3 {
  color: var(--text);
  margin-top: 30px;
  margin-bottom: 15px;
}

code {
  background: var(--panel);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
  font-size: 0.9em;
  border: 1px solid var(--border);
}

pre {
  background: var(--panel);
  padding: 15px;
  border-radius: 8px;
  overflow-x: auto;
  border: 1px solid var(--border);
}

/* Responsive */
@media (max-width: 768px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .nav {
    width: 100%;
    justify-content: space-between;
  }
  
  .search {
    width: 100%;
  }
  
  .search input {
    flex: 1;
  }
  
  .hero h1 {
    font-size: 32px;
  }
  
  .grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  }
}