/* ===== DevAgentLab - AI Tools & Developer Productivity ===== */
/* Mobile-first, clean, fast, AdSense-optimized */

:root {
  --bg: #ffffff;
  --bg-alt: #f7f8fa;
  --text: #1a1a2e;
  --text-muted: #6b7280;
  --accent: #ff6b35;
  --accent-hover: #e55a2b;
  --border: #e5e7eb;
  --card-shadow: 0 1px 3px rgba(0,0,0,0.08);
  --max-width: 720px;
}

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

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans", Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* Layout */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

/* Nav */
.nav {
  padding: 20px 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 40px;
}
.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--text);
  text-decoration: none;
}
.nav-logo span { color: var(--accent); }
.nav-links { display: flex; gap: 24px; }
.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }

/* Hero */
.hero { padding: 60px 0 40px; text-align: center; }
.hero h1 { font-size: 2rem; font-weight: 800; margin-bottom: 12px; line-height: 1.3; }
.hero p { color: var(--text-muted); font-size: 1.05rem; max-width: 600px; margin: 0 auto; }
.hero .tagline { margin-top: 8px; font-size: 0.85rem; color: var(--accent); font-weight: 600; }

/* Article List */
.article-list { list-style: none; }
.article-list li {
  padding: 24px 0;
  border-bottom: 1px solid var(--border);
}
.article-list li:last-child { border-bottom: none; }

.article-list a {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  display: block;
  margin-bottom: 6px;
  transition: color 0.2s;
}
.article-list a:hover { color: var(--accent); }

.article-list .meta {
  font-size: 0.82rem;
  color: var(--text-muted);
  display: flex;
  gap: 12px;
  align-items: center;
}
.article-list .meta .tag {
  background: var(--bg-alt);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.75rem;
  color: var(--text-muted);
}
.article-list .desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 6px;
  line-height: 1.5;
}

/* Category Filter */
.categories {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}
.category-btn {
  padding: 6px 16px;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text-muted);
  font-size: 0.82rem;
  cursor: pointer;
  transition: all 0.2s;
}
.category-btn:hover { border-color: var(--accent); color: var(--accent); }
.category-btn.active { background: var(--accent); color: white; border-color: var(--accent); }

/* Article Page */
.article-header { margin-bottom: 32px; }
.article-header h1 { font-size: 1.8rem; font-weight: 800; line-height: 1.3; margin-bottom: 12px; }
.article-header .meta { font-size: 0.85rem; color: var(--text-muted); display: flex; gap: 16px; flex-wrap: wrap; }

.article-body { font-size: 1rem; line-height: 1.8; }
.article-body h2 { font-size: 1.4rem; font-weight: 700; margin: 32px 0 12px; }
.article-body h3 { font-size: 1.15rem; font-weight: 600; margin: 24px 0 8px; }
.article-body p { margin-bottom: 16px; }
.article-body ul, .article-body ol { margin: 0 0 16px 24px; }
.article-body li { margin-bottom: 6px; }
.article-body code {
  background: var(--bg-alt);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.88em;
  font-family: "SF Mono", "Fira Code", "Fira Mono", Menlo, Consolas, monospace;
}
.article-body pre {
  background: #1a1a2e;
  color: #e5e7eb;
  padding: 16px;
  border-radius: 8px;
  overflow-x: auto;
  margin-bottom: 20px;
  font-size: 0.88rem;
  line-height: 1.5;
}
.article-body pre code { background: none; padding: 0; font-size: 0.88rem; }
.article-body img { max-width: 100%; border-radius: 8px; margin: 16px 0; }
.article-body blockquote {
  border-left: 3px solid var(--accent);
  padding-left: 16px;
  margin: 16px 0;
  color: var(--text-muted);
  font-style: italic;
}
.article-body a { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; }

/* Table of Contents */
.toc {
  background: var(--bg-alt);
  border-radius: 8px;
  padding: 16px 20px;
  margin-bottom: 32px;
  font-size: 0.9rem;
}
.toc-title { font-weight: 600; margin-bottom: 8px; font-size: 0.85rem; text-transform: uppercase; color: var(--text-muted); }
.toc ol { margin: 0 0 0 20px; }
.toc li { margin-bottom: 4px; }
.toc a { color: var(--text-muted); text-decoration: none; }
.toc a:hover { color: var(--text); }

/* Pages: About / Contact / Privacy */
.page-content { max-width: 600px; margin: 0 auto; padding: 40px 0; }
.page-content h1 { font-size: 1.8rem; font-weight: 800; margin-bottom: 20px; }
.page-content h2 { font-size: 1.3rem; font-weight: 700; margin: 28px 0 12px; }
.page-content p { margin-bottom: 16px; color: var(--text-muted); line-height: 1.7; }

/* Footer */
.footer {
  margin-top: 60px;
  padding: 32px 0;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.82rem;
  color: var(--text-muted);
}
.footer a { color: var(--text-muted); text-decoration: none; }
.footer a:hover { color: var(--text); }

/* Language Toggle */
.lang-switch {
  display: flex;
  gap: 4px;
  background: var(--bg-alt);
  border-radius: 6px;
  padding: 2px;
}
.lang-btn {
  border: none;
  background: transparent;
  color: var(--text-muted);
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 0.78rem;
  cursor: pointer;
  font-weight: 500;
  transition: all 0.2s;
}
.lang-btn.active {
  background: white;
  color: var(--text);
  box-shadow: 0 1px 2px rgba(0,0,0,0.1);
}
[data-lang="zh"] { display: none; }
html[lang="zh"] [data-lang="zh"] { display: inline; }
html[lang="zh"] [data-lang="en"] { display: none; }

/* Responsive */
@media (max-width: 600px) {
  .hero h1 { font-size: 1.5rem; }
  .article-header h1 { font-size: 1.4rem; }
  .nav-links { gap: 12px; }
  .nav-links a { font-size: 0.82rem; }
}