/* ==========================================
   知识库测试站点 — 主样式表
   构石 · 知识沉淀之地
   ========================================== */

:root {
  --bg: #faf8f5;
  --card-bg: #ffffff;
  --text: #2c2416;
  --text-secondary: #6b5e4a;
  --accent: #8b4513;
  --accent-light: #d4a574;
  --border: #e0d5c1;
  --tag-bg: #f5efe4;
  --tag-text: #8b5e3c;
  --hero-bg: #1a1510;
  --hero-text: #f0e6d3;
  --radius: 4px;
}

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

body {
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", Georgia, "Times New Roman", serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
}

/* ===== TOP BAR ===== */
.topbar {
  background: var(--hero-bg);
  color: var(--hero-text);
  padding: 10px 0;
  font-size: 0.82rem;
  text-align: center;
  letter-spacing: 1px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
.topbar span { opacity: 0.7; }

/* ===== HEADER ===== */
.header {
  background: var(--hero-bg);
  padding: 60px 24px 64px;
  text-align: center;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.header .logo-line {
  font-size: 0.85rem;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: var(--accent-light);
  margin-bottom: 18px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
.header h1 {
  font-size: 3rem;
  font-weight: 900;
  letter-spacing: 6px;
  color: var(--hero-text);
  margin-bottom: 14px;
}
.header .subtitle {
  font-size: 1.1rem;
  color: rgba(240,230,211,0.6);
  font-style: italic;
  letter-spacing: 2px;
}
.header .motto {
  margin-top: 24px;
  font-size: 0.9rem;
  color: rgba(240,230,211,0.45);
  letter-spacing: 3px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

/* ===== NAV ===== */
.nav {
  background: var(--hero-bg);
  border-bottom: 1px solid rgba(255,255,255,0.08);
  padding: 0 24px;
  text-align: center;
}
.nav a {
  display: inline-block;
  padding: 14px 22px;
  color: rgba(240,230,211,0.7);
  text-decoration: none;
  font-size: 0.9rem;
  letter-spacing: 2px;
  transition: color 0.2s;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
.nav a:hover { color: var(--hero-text); }

/* ===== CONTAINER ===== */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 48px 20px 60px;
}

/* ===== SECTION HEADERS ===== */
.section-title {
  text-align: center;
  margin: 48px 0 32px;
}
.section-title h2 {
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: 4px;
  color: var(--text);
  margin-bottom: 8px;
}
.section-title .line {
  display: inline-block;
  width: 40px;
  height: 2px;
  background: var(--accent);
}
.section-title p {
  margin-top: 10px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-style: italic;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

/* ===== ARTICLE CARDS ===== */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.article-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: box-shadow 0.2s, transform 0.2s;
  display: flex;
  flex-direction: column;
}
.article-card:hover {
  box-shadow: 0 4px 16px rgba(0,0,0,0.08);
  transform: translateY(-2px);
}
.article-card .domain {
  font-size: 0.72rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
.article-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
  line-height: 1.5;
  color: var(--text);
}
.article-card h3 a {
  color: inherit;
  text-decoration: none;
}
.article-card h3 a:hover { color: var(--accent); }
.article-card .excerpt {
  font-size: 0.85rem;
  color: var(--text-secondary);
  flex: 1;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}
.article-card .meta {
  margin-top: 16px;
  font-size: 0.78rem;
  color: #aaa;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.article-card .meta .rating {
  color: var(--accent);
  font-weight: 600;
}

/* ===== PLACEHOLDER BADGE ===== */
.badge-placeholder {
  display: inline-block;
  background: var(--tag-bg);
  color: var(--tag-text);
  padding: 2px 10px;
  border-radius: 2px;
  font-size: 0.7rem;
  letter-spacing: 1px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

/* ===== ABOUT SECTION ===== */
.about-block {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px;
  text-align: center;
}
.about-block p {
  max-width: 600px;
  margin: 0 auto 12px;
  color: var(--text-secondary);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 0.95rem;
}
.about-block .stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  margin-top: 24px;
  flex-wrap: wrap;
}
.about-block .stat { text-align: center; }
.about-block .stat .number {
  font-size: 1.8rem;
  font-weight: 900;
  color: var(--accent);
  letter-spacing: 1px;
}
.about-block .stat .label {
  font-size: 0.78rem;
  color: var(--text-secondary);
  letter-spacing: 2px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

/* ===== SUBMISSION CTA ===== */
.cta-block {
  background: var(--hero-bg);
  color: var(--hero-text);
  text-align: center;
  padding: 48px 24px;
  border-radius: var(--radius);
  margin-top: 48px;
}
.cta-block h2 {
  font-size: 1.4rem;
  letter-spacing: 4px;
  margin-bottom: 12px;
}
.cta-block p {
  color: rgba(240,230,211,0.6);
  margin-bottom: 24px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 0.9rem;
}
.cta-block .btn {
  display: inline-block;
  background: transparent;
  border: 1px solid var(--accent-light);
  color: var(--accent-light);
  padding: 12px 36px;
  font-size: 0.9rem;
  letter-spacing: 3px;
  text-decoration: none;
  border-radius: var(--radius);
  transition: all 0.2s;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
.cta-block .btn:hover {
  background: var(--accent-light);
  color: var(--hero-bg);
}

/* ===== FOOTER ===== */
.footer {
  text-align: center;
  padding: 40px 24px;
  font-size: 0.8rem;
  color: #aaa;
  letter-spacing: 1px;
  border-top: 1px solid var(--border);
  margin-top: 48px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
.footer a { color: var(--accent); text-decoration: none; }
.footer a:hover { text-decoration: underline; }

/* ===== RESPONSIVE ===== */
@media (max-width: 640px) {
  .header h1 { font-size: 2rem; letter-spacing: 3px; }
  .header { padding: 40px 16px 44px; }
  .nav a { padding: 10px 14px; font-size: 0.82rem; letter-spacing: 1px; }
  .articles-grid { grid-template-columns: 1fr; }
  .about-block .stats { gap: 24px; }
  .about-block .stat .number { font-size: 1.4rem; }
}