:root {
  --primary: #0a1628;
  --accent: #00d4aa;
  --accent2: #0099ff;
  --warm: #ff6b35;
  --glass: rgba(255,255,255,0.06);
  --glass-border: rgba(255,255,255,0.08);
  --text: #e8ecf1;
  --text-dim: #8a95a8;
  --gradient-1: linear-gradient(135deg, #00d4aa 0%, #0099ff 100%);
  --gradient-2: linear-gradient(135deg, #ff6b35 0%, #ff3366 100%);
  --card-bg: rgba(255,255,255,0.03);
  --card-bg-hover: rgba(255,255,255,0.05);
  --nav-bg: rgba(10,22,40,.92);
  --mobile-nav-bg: rgba(10,22,40,.98);
  --mobile-nav-solid: #0a1628;
  --float-card-bg: rgba(10,22,40,.85);
  --hero-overlay: rgba(10,22,40,.95);
  --footer-bg: rgba(255,255,255,0.02);
  --input-bg: rgba(255,255,255,0.05);
  --shadow-color: rgba(0,0,0,.3);
  --particle-color: rgba(0, 212, 170, 0.3);
  --line-color: rgba(0, 212, 170, 0.03);
  --theme-toggle-bg: rgba(255,255,255,0.08);
  --theme-toggle-hover: rgba(255,255,255,0.15);
}

[data-theme="light"] {
  --primary: #f5f7fa;
  --glass: rgba(0,0,0,0.03);
  --glass-border: rgba(0,0,0,0.08);
  --text: #1a2332;
  --text-dim: #5a6577;
  --card-bg: rgba(0,0,0,0.02);
  --card-bg-hover: rgba(0,0,0,0.04);
  --nav-bg: rgba(245,247,250,.92);
  --mobile-nav-bg: rgba(245,247,250,.98);
  --mobile-nav-solid: #f5f7fa;
  --float-card-bg: rgba(255,255,255,.92);
  --hero-overlay: rgba(245,247,250,.95);
  --footer-bg: rgba(0,0,0,0.02);
  --input-bg: rgba(0,0,0,0.04);
  --shadow-color: rgba(0,0,0,.08);
  --particle-color: rgba(0, 180, 140, 0.15);
  --line-color: rgba(0, 180, 140, 0.02);
  --theme-toggle-bg: rgba(0,0,0,0.06);
  --theme-toggle-hover: rgba(0,0,0,0.12);
}

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

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

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--primary);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
}

/* ====== Scrollbar ====== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--primary); }
::-webkit-scrollbar-thumb:hover { background: var(--accent2); }
::-webkit-scrollbar-thumb { background: var(--accent); border-radius: 3px; }

/* ====== Utility ====== */
.container { max-width: 1280px; margin: 0 auto; padding: 0 2rem; }
.section-label {
  display: inline-flex; align-items: center; gap: .5rem;
  font-size: .75rem; letter-spacing: 3px; text-transform: uppercase;
  color: var(--accent); margin-bottom: 1rem;
  font-weight: 500;
}
.section-label::before {
  content: ''; display: block; width: 32px; height: 1px; background: var(--accent);
}
.section-title {
  font-size: clamp(2rem, 4vw, 3rem); font-weight: 700;
  line-height: 1.2; margin-bottom: 1.5rem;
}
.section-desc {
  font-size: 1.05rem; color: var(--text-dim);
  max-width: 640px; line-height: 1.8;
}
.gradient-text {
  background: var(--gradient-1); -webkit-background-clip: text;
  -webkit-text-fill-color: transparent; background-clip: text;
}
.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: .875rem 2rem; border-radius: 50px; font-size: .95rem;
  font-weight: 500; text-decoration: none; transition: all .3s ease;
  cursor: pointer; border: none; font-family: inherit;
}
.btn-primary {
  background: var(--gradient-1); color: #000;
  box-shadow: 0 4px 24px rgba(0,212,170,.25);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 32px rgba(0,212,170,.35); }
.btn-outline {
  background: transparent; color: var(--text);
  border: 1px solid rgba(255,255,255,.15);
}
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }