:root {
  --bg: #0d1117;
  --bg-alt: #111827;
  --surface: #161b22;
  --surface-card: #1c2333;
  --surface-hover: #21283a;
  --border: rgba(255, 255, 255, 0.06);
  --border-strong: rgba(255, 255, 255, 0.1);
  --text: #8b949e;
  --text-muted: #5c6574;
  --text-heading: #e6edf3;
  --text-bright: #ffffff;
  --accent: #58a6ff;
  --accent-hover: #79b8ff;
  --accent-dim: rgba(88, 166, 255, 0.08);
  --radius: 8px;
  --radius-lg: 12px;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
.site-header-bar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(13, 17, 23, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.site-header-bar nav {
  display: flex; justify-content: space-between; align-items: center;
  padding: 0 32px; height: 52px; max-width: 1200px; margin: 0 auto;
}
.logo { display: flex; align-items: baseline; text-decoration: none; font-size: 1.05rem; }
.logo-bold { font-weight: 700; color: var(--text-bright); }
.logo-light { font-weight: 450; color: var(--text); }
.signin-btn {
  color: var(--text); text-decoration: none; font-size: .82rem; font-weight: 500;
  padding: 5px 14px; border: 1px solid var(--border-strong); border-radius: 6px;
}
.signin-btn:hover { border-color: var(--accent); color: var(--text-heading); }
.site-footer-bar { background: var(--bg); border-top: 1px solid var(--border); margin-top: 48px; }
.footer-content {
  max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between;
  align-items: center; padding: 36px 32px; gap: 32px; flex-wrap: wrap;
}
.footer-logo { font-size: .9rem; color: var(--text-heading); }
.footer-tag { font-size: .75rem; color: var(--text-muted); display: block; }
.footer-links { display: flex; gap: 20px; flex-wrap: wrap; }
.footer-links a { color: var(--text-muted); text-decoration: none; font-size: .82rem; }
.footer-links a:hover { color: var(--accent); }
.footer-bottom {
  text-align: center; padding: 14px 32px; border-top: 1px solid var(--border);
  font-size: .72rem; color: var(--text-muted);
}
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 10px 22px; border-radius: 6px; font-size: .88rem; font-weight: 500;
  cursor: pointer; text-decoration: none; border: none;
  background: var(--accent); color: #fff;
}
.btn:hover { background: var(--accent-hover); }