/* ===== CSS Variables ===== */
:root {
  --bg: #ffffff;
  --fg: #171717;
  --primary: #3b82f6;
  --primary-dark: #2563eb;
  --primary-light: #dbeafe;
  --border: #e5e7eb;
  --code-bg: #f3f4f6;
  --card-bg: #ffffff;
  --nav-bg: #ffffff;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a0a0a;
    --fg: #ededed;
    --border: #374151;
    --code-bg: #1f2937;
    --card-bg: #1f2937;
    --nav-bg: #111827;
    --primary-light: #1e3a5f;
    --gray-50: #111827;
    --gray-100: #1f2937;
  }
}

/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", sans-serif;
  color: var(--fg);
  background: var(--bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; border-radius: 8px; }

/* ===== Skip Link ===== */
.skip-link {
  position: absolute; top: -100%; left: 16px;
  background: var(--primary); color: #fff;
  padding: 8px 16px; border-radius: 4px; z-index: 1000;
}
.skip-link:focus { top: 8px; }

/* ===== Navbar ===== */
.navbar {
  background: var(--nav-bg);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 100;
}
.nav-container {
  max-width: 1200px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 16px; height: 60px;
}
.nav-logo {
  display: flex; align-items: center; gap: 8px;
  font-size: 1.25rem; font-weight: 700;
  color: var(--primary); text-decoration: none;
}
.nav-logo-img { height: 24px; width: auto; border-radius: 0; }
.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-link {
  display: flex; align-items: center; gap: 6px;
  padding: 6px 12px; border-radius: 6px;
  font-size: 0.875rem; font-weight: 500;
  color: var(--gray-600); text-decoration: none;
  transition: background 0.2s, color 0.2s;
}
.nav-link:hover { background: var(--gray-100); color: var(--gray-900); text-decoration: none; }
.nav-link.active { background: var(--primary-light); color: var(--primary-dark); }

/* Mobile toggle */
.nav-toggle {
  display: none; background: none; border: none; cursor: pointer;
  flex-direction: column; gap: 5px; padding: 8px;
}
.nav-toggle span {
  display: block; width: 24px; height: 2px;
  background: var(--gray-600); transition: 0.3s;
}

/* ===== Search ===== */
.search-box { position: relative; margin-left: 12px; }
.search-box input {
  width: 200px; padding: 6px 12px 6px 32px;
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--bg); color: var(--fg);
  font-size: 0.875rem; outline: none;
}
.search-box input:focus { border-color: var(--primary); box-shadow: 0 0 0 2px rgba(59,130,246,0.2); }
.search-box::before {
  content: "🔍"; position: absolute; left: 8px; top: 50%;
  transform: translateY(-50%); font-size: 0.75rem; pointer-events: none;
}
.search-results {
  display: none; position: absolute; top: 100%; left: 0; right: 0;
  margin-top: 4px; background: var(--card-bg);
  border: 1px solid var(--border); border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1); max-height: 320px;
  overflow-y: auto; z-index: 200; min-width: 300px;
}
.search-results.open { display: block; }
.search-result-item {
  display: block; padding: 10px 14px;
  border-bottom: 1px solid var(--gray-100);
  color: var(--fg); text-decoration: none;
}
.search-result-item:last-child { border-bottom: none; }
.search-result-item:hover { background: var(--gray-50); text-decoration: none; }
.search-result-item h4 { font-size: 0.875rem; margin-bottom: 2px; }
.search-result-item p { font-size: 0.75rem; color: var(--gray-500); }
.search-result-item mark { background: #fef08a; font-weight: 600; }
.search-no-result { padding: 12px 14px; font-size: 0.875rem; color: var(--gray-500); }

/* ===== Hero ===== */
.hero {
  text-align: center; padding: 80px 16px 48px;
  max-width: 800px; margin: 0 auto;
}
.hero h1 { font-size: 2.75rem; font-weight: 800; margin-bottom: 16px; line-height: 1.3; }
.hero .subtitle { font-size: 1.2rem; color: var(--gray-500); margin-bottom: 32px; }

/* Quick start selector */
.quick-start { margin-top: 32px; }
.quick-start h3 { font-size: 1rem; color: var(--gray-500); margin-bottom: 16px; }
.os-selector { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }
.os-btn {
  display: flex; align-items: center; gap: 8px;
  padding: 12px 24px; border: 2px solid var(--border);
  border-radius: 12px; background: var(--card-bg);
  color: var(--fg); text-decoration: none;
  font-weight: 500; font-size: 0.95rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.os-btn:hover { border-color: var(--primary); box-shadow: 0 2px 12px rgba(59,130,246,0.15); text-decoration: none; }
.os-btn svg { width: 20px; height: 20px; }

/* News ticker */
.news-bar {
  max-width: 800px; margin: 0 auto 32px;
  padding: 12px 20px; background: var(--gray-50);
  border: 1px solid var(--border); border-radius: 10px;
  font-size: 0.875rem; color: var(--gray-600);
  display: flex; align-items: center; gap: 12px;
  overflow: hidden;
}
.news-bar .news-label {
  background: var(--primary); color: #fff;
  padding: 2px 10px; border-radius: 6px;
  font-size: 0.75rem; font-weight: 600; white-space: nowrap;
}
.news-bar .news-content { overflow: hidden; white-space: nowrap; text-overflow: ellipsis; }

/* ===== Sections ===== */
.section { max-width: 1000px; margin: 0 auto; padding: 0 16px 56px; }
.section-title { font-size: 1.5rem; font-weight: 700; margin-bottom: 8px; }
.section-desc { font-size: 1rem; color: var(--gray-500); margin-bottom: 24px; }

/* ===== Card Grid ===== */
.card-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.card-grid-4 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.card {
  display: block; padding: 24px; background: var(--card-bg);
  border: 1px solid var(--border); border-radius: 12px;
  text-decoration: none; color: var(--fg);
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
  position: relative;
}
.card:hover { border-color: var(--primary); box-shadow: 0 4px 16px rgba(0,0,0,0.08); text-decoration: none; transform: translateY(-2px); }
.card-icon { color: var(--primary); margin-bottom: 12px; }
.card-icon svg { width: 32px; height: 32px; }
.card h3 { font-size: 1.125rem; margin-bottom: 8px; }
.card p { font-size: 0.875rem; color: var(--gray-500); line-height: 1.6; }
.card .card-tag {
  display: inline-block; margin-top: 10px;
  padding: 2px 10px; font-size: 0.7rem; font-weight: 600;
  border-radius: 12px;
}
.card .card-tag.recommend { background: #dcfce7; color: #166534; }
.card .card-tag.new { background: #fef3c7; color: #92400e; }

/* Badge */
.badge {
  display: inline-block; margin-top: 12px;
  padding: 2px 10px; font-size: 0.75rem; font-weight: 500;
  background: var(--gray-100); color: var(--gray-500);
  border-radius: 12px;
}

/* ===== Tutorial Layout ===== */
.tutorial-wrapper {
  max-width: 1200px; margin: 0 auto; padding: 32px 16px;
  display: grid; grid-template-columns: 240px 1fr; gap: 32px;
}
.toc-sidebar { position: sticky; top: 80px; align-self: start; }
.toc-sidebar h3 {
  font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em;
  color: var(--gray-400); margin-bottom: 12px;
}
.toc-sidebar ul { list-style: none; }
.toc-sidebar li a {
  display: block; padding: 4px 0; font-size: 0.875rem;
  color: var(--gray-600); text-decoration: none; transition: color 0.2s;
}
.toc-sidebar li a:hover { color: var(--primary); }
.toc-sidebar li a.toc-active { color: var(--primary); font-weight: 500; }
.toc-sidebar li.toc-level-3 a { padding-left: 16px; }

/* Mobile TOC toggle */
.toc-mobile-toggle {
  display: none; width: 100%; padding: 10px 16px;
  background: var(--gray-100); border: none; border-radius: 8px;
  font-size: 0.875rem; color: var(--gray-700); cursor: pointer;
  text-align: left; margin-bottom: 16px;
}

/* ===== Tutorial Content ===== */
.tutorial-content { max-width: 800px; }
.tutorial-content h1 { font-size: 2.25rem; font-weight: 700; margin-bottom: 24px; }
.tutorial-content h2 { font-size: 1.75rem; font-weight: 600; margin: 40px 0 16px; padding-top: 16px; border-top: 1px solid var(--border); }
.tutorial-content h3 { font-size: 1.375rem; font-weight: 600; margin: 32px 0 12px; }
.tutorial-content p { margin-bottom: 16px; }
.tutorial-content ul, .tutorial-content ol { margin: 0 0 16px 24px; }
.tutorial-content li { margin-bottom: 8px; }
.tutorial-content strong { font-weight: 600; }

/* Info & Warning boxes */
.info-box {
  background: #eff6ff; border-left: 4px solid var(--primary);
  padding: 12px 16px; border-radius: 0 8px 8px 0; margin: 16px 0;
  font-size: 0.9rem;
}
.warning-box {
  background: #fef2f2; border-left: 4px solid var(--danger);
  padding: 12px 16px; border-radius: 0 8px 8px 0; margin: 16px 0;
  font-size: 0.9rem;
}
.success-box {
  background: #ecfdf5; border-left: 4px solid var(--success);
  padding: 12px 16px; border-radius: 0 8px 8px 0; margin: 16px 0;
  font-size: 0.9rem;
}
@media (prefers-color-scheme: dark) {
  .info-box { background: #1e293b; }
  .warning-box { background: #1c1917; }
  .success-box { background: #0f1f17; }
}

/* Code blocks */
.code-block {
  position: relative; margin: 16px 0; border-radius: 8px;
  border: 1px solid var(--border); overflow: hidden;
}
.code-header {
  display: flex; justify-content: space-between; align-items: center;
  padding: 8px 16px; background: var(--gray-100);
  border-bottom: 1px solid var(--border);
  font-size: 0.75rem; color: var(--gray-500);
}
.copy-btn {
  background: none; border: none; cursor: pointer;
  font-size: 0.75rem; color: var(--gray-500); padding: 2px 8px;
  border-radius: 4px; transition: background 0.2s;
}
.copy-btn:hover { background: var(--gray-200); }
.code-block pre {
  margin: 0; padding: 16px; background: var(--code-bg);
  overflow-x: auto; font-size: 0.875rem; line-height: 1.6;
}
.code-block code { font-family: "Fira Code", "Consolas", "Monaco", monospace; }

/* Tables */
.comparison-table { width: 100%; border-collapse: collapse; margin: 16px 0 24px; font-size: 0.9rem; }
.comparison-table th, .comparison-table td { border: 1px solid var(--border); padding: 10px 14px; text-align: left; }
.comparison-table th { background: var(--gray-100); font-weight: 600; color: var(--gray-800); }
.comparison-table tr:nth-child(even) { background: var(--gray-50); }
@media (prefers-color-scheme: dark) {
  .comparison-table th { background: var(--gray-800); color: var(--fg); }
  .comparison-table tr:nth-child(even) { background: rgba(255,255,255,0.03); }
}

/* FAQ */
.faq-item { margin-bottom: 24px; }
.faq-item h3, .faq-item h4 { color: var(--gray-900); margin-bottom: 8px; }

/* Skills table */
.skills-table { width: 100%; border-collapse: collapse; margin: 16px 0 24px; font-size: 0.9rem; }
.skills-table th, .skills-table td { border: 1px solid var(--border); padding: 10px 14px; text-align: left; }
.skills-table th { background: var(--gray-100); font-weight: 600; }
.skills-table code { background: var(--code-bg); padding: 2px 6px; border-radius: 4px; font-size: 0.8rem; }

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border);
  font-size: 0.875rem; color: var(--gray-500);
  margin-top: 48px;
  padding: 0;
}
.footer-links {
  text-align: center;
  padding: 16px 20px 8px;
}
.footer-links a {
  color: var(--gray-500);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-links a:hover {
  color: var(--primary);
  text-decoration: underline;
}
.footer-divider {
  margin: 0 12px;
  color: var(--border);
}
.footer-bottom {
  text-align: center;
  padding: 8px 20px 16px;
  font-size: 0.8rem;
  color: var(--gray-500);
}

/* ===== Legal Pages ===== */
.legal-page {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 20px 60px;
  line-height: 1.8;
}
.legal-page h1 {
  font-size: 1.8rem;
  margin-bottom: 8px;
}
.legal-updated {
  color: var(--gray-500);
  font-size: 0.9rem;
  margin-bottom: 32px;
}
.legal-page h2 {
  font-size: 1.2rem;
  margin-top: 28px;
  margin-bottom: 12px;
}
.legal-page h3 {
  font-size: 1.05rem;
  margin-top: 20px;
  margin-bottom: 8px;
}
.legal-page ul {
  padding-left: 20px;
}
.legal-page ul li {
  margin-bottom: 6px;
}
.legal-page a {
  color: var(--primary);
}

/* ===== Skills Grid ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  margin: 24px 0;
}
.skill-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  background: var(--bg);
  transition: all 0.2s;
  position: relative;
}
.skill-card:hover {
  border-color: var(--primary);
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}
.skill-rank {
  position: absolute;
  top: 12px;
  right: 12px;
  background: var(--primary);
  color: white;
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 12px;
  font-weight: 600;
}
.skill-name {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 0 0 8px;
  color: var(--text);
  padding-right: 40px;
}
.skill-desc {
  font-size: 0.9rem;
  color: var(--gray-600);
  line-height: 1.5;
  margin-bottom: 12px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.skill-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--gray-500);
  padding-top: 8px;
  border-top: 1px solid var(--border);
}
.skill-author {
  color: var(--primary);
}
.skill-downloads {
  font-weight: 600;
}
.skills-table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
}
.skills-table th,
.skills-table td {
  padding: 12px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
.skills-table th {
  background: var(--gray-100);
  font-weight: 600;
}
.skills-table code {
  background: var(--gray-100);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav-links { 
    display: none; position: absolute; top: 60px; left: 0; right: 0;
    background: var(--nav-bg); border-bottom: 1px solid var(--border);
    flex-direction: column; padding: 16px; gap: 4px;
  }
  .nav-links.open { display: flex; }
  .nav-toggle { display: flex; }
  .search-box { margin-left: 0; width: 100%; }
  .search-box input { width: 100%; }

  .hero h1 { font-size: 1.75rem; }
  .hero .subtitle { font-size: 1rem; }
  .hero { padding: 48px 16px 32px; }
  .os-selector { flex-direction: column; align-items: stretch; }
  .os-btn { justify-content: center; }

  .tutorial-wrapper { grid-template-columns: 1fr; }
  .toc-sidebar { display: none; position: static; }
  .toc-sidebar.open, .toc-sidebar.mobile-open { display: block; }
  .toc-mobile-toggle { display: block; }

  .comparison-table, .skills-table { font-size: 0.8rem; }
  .comparison-table th, .comparison-table td,
  .skills-table th, .skills-table td { padding: 6px 8px; }

  .card-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.5rem; }
  .section-title { font-size: 1.25rem; }
  .tutorial-content h1 { font-size: 1.75rem; }
  .tutorial-content h2 { font-size: 1.375rem; }
  .tutorial-content h3 { font-size: 1.125rem; }
}