:root {
  --bg-primary: #0b0f19;
  --bg-secondary: #151d30;
  --bg-card: #1c2640;
  --bg-card-hover: #233052;
  --text-main: #f8fafc;
  --text-sub: #94a3b8;
  --text-muted: #64748b;
  --accent: #38bdf8;
  --accent-hover: #0ea5e9;
  --accent-green: #10b981;
  --accent-orange: #f59e0b;
  --border: #263554;
  --radius: 12px;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang HK", "Noto Sans HK", "Microsoft JhengHei", sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { 
  background: var(--bg-primary); 
  color: var(--text-main); 
  font-family: var(--font-family); 
  line-height: 1.6; 
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; transition: all 0.2s ease; }
a:hover { color: var(--accent); }

.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 16px; }

header { 
  background: rgba(11, 15, 25, 0.95); 
  backdrop-filter: blur(12px); 
  border-bottom: 1px solid var(--border); 
  position: sticky; 
  top: 0; 
  z-index: 100; 
}
.nav-wrap { 
  display: flex; 
  align-items: center; 
  justify-content: space-between; 
  min-height: 60px; 
  padding: 8px 0;
  flex-wrap: wrap;
  gap: 8px;
}
.logo { 
  font-size: 20px; 
  font-weight: 800; 
  color: var(--accent); 
  display: flex; 
  align-items: center; 
  gap: 6px; 
}
.logo span { color: #fff; font-size: 14px; font-weight: 500; }

nav { width: 100%; overflow-x: auto; padding-bottom: 4px; }
@media (min-width: 768px) {
  nav { width: auto; overflow-x: visible; padding-bottom: 0; }
  .logo { font-size: 24px; }
  .logo span { font-size: 16px; }
}

nav ul { 
  display: flex; 
  gap: 8px; 
  list-style: none; 
  white-space: nowrap;
}
nav a { 
  display: block;
  font-weight: 600; 
  font-size: 14px; 
  color: var(--text-sub); 
  padding: 6px 12px;
  border-radius: 8px;
  background: rgba(30, 41, 59, 0.4);
}
nav a.active, nav a:hover { 
  color: #fff; 
  background: var(--accent-hover); 
}

.grid-1 { display: grid; grid-template-columns: 1fr; gap: 16px; }
.grid-2 { display: grid; grid-template-columns: 1fr; gap: 16px; }
.grid-3 { display: grid; grid-template-columns: 1fr; gap: 16px; }

@media (min-width: 768px) {
  .grid-2 { grid-template-columns: repeat(2, 1fr); gap: 24px; }
  .grid-3 { grid-template-columns: repeat(3, 1fr); gap: 24px; }
}

.card { 
  background: var(--bg-secondary); 
  border: 1px solid var(--border); 
  border-radius: var(--radius); 
  overflow: hidden; 
  transition: transform 0.2s ease, border-color 0.2s ease; 
}
.card:hover { 
  transform: translateY(-2px); 
  border-color: var(--accent); 
  background: var(--bg-card-hover);
}
.card-body { padding: 18px; }
@media (min-width: 768px) { .card-body { padding: 24px; } }

.tag { 
  display: inline-block; 
  padding: 3px 8px; 
  border-radius: 6px; 
  font-size: 11px; 
  font-weight: 700; 
  margin-bottom: 8px; 
}
.tag-blue { background: rgba(56, 189, 248, 0.15); color: var(--accent); }
.tag-green { background: rgba(16, 185, 129, 0.15); color: var(--accent-green); }
.tag-orange { background: rgba(245, 158, 11, 0.15); color: var(--accent-orange); }

.score-badge { 
  display: inline-flex; 
  align-items: center; 
  justify-content: center; 
  width: 40px; 
  height: 40px; 
  background: var(--accent-green); 
  color: #fff; 
  font-weight: 800; 
  border-radius: 8px; 
  font-size: 16px; 
  flex-shrink: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: 8px;
  font-weight: 700;
  font-size: 14px;
  cursor: pointer;
  border: none;
  transition: all 0.2s ease;
  min-height: 44px;
}
.btn-primary { background: var(--accent); color: #0b0f19; }
.btn-primary:hover { background: var(--accent-hover); color: #fff; }
.btn-secondary { background: var(--bg-card); color: #fff; border: 1px solid var(--border); }
.btn-secondary:hover { border-color: var(--accent); color: var(--accent); }

.prose { 
  background: var(--bg-secondary); 
  border: 1px solid var(--border); 
  border-radius: var(--radius); 
  padding: 20px; 
  margin: 20px 0; 
}
@media (min-width: 768px) { .prose { padding: 40px; margin: 30px 0; } }

.prose h1 { font-size: clamp(20px, 4vw, 28px); margin-bottom: 12px; color: #fff; line-height: 1.3; }
.prose h2 { font-size: clamp(17px, 3vw, 22px); margin: 20px 0 10px; color: var(--accent); border-bottom: 1px solid var(--border); padding-bottom: 6px; }
.prose p { color: var(--text-sub); margin-bottom: 14px; font-size: 14px; line-height: 1.7; }
.prose ul { margin-left: 20px; margin-bottom: 16px; color: var(--text-sub); font-size: 14px; }
.prose li { margin-bottom: 6px; }

footer { 
  background: #060913; 
  border-top: 1px solid var(--border); 
  padding: 40px 0 20px; 
  margin-top: 40px; 
  font-size: 13px; 
  color: var(--text-sub); 
}
.footer-grid { display: grid; grid-template-columns: 1fr; gap: 24px; margin-bottom: 30px; }
@media (min-width: 768px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; gap: 30px; } }

.footer-col h4 { color: #fff; margin-bottom: 12px; font-size: 15px; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 8px; }
.footer-bottom { border-top: 1px solid var(--border); padding-top: 20px; text-align: center; font-size: 12px; }