/* roulang page: index */
:root {
      --color-primary: #0F172A;
      --color-accent-green: #10B981;
      --color-accent-blue: #0284C7;
      --color-accent-orange: #F97316;
      --color-bg-light: #F8FAFC;
      --color-bg-card: #FFFFFF;
      --color-text-main: #0F172A;
      --color-text-muted: #64748B;
      --shadow-soft: 0 4px 20px -2px rgba(15, 23, 42, 0.05);
      --shadow-hover: 0 10px 25px -4px rgba(15, 23, 42, 0.1);
    }
    body {
      font-family: var(--font-sans, 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif);
      line-height: 1.75;
      letter-spacing: 0.02em;
      color: var(--color-text-main);
      background-color: var(--color-bg-light);
      -webkit-font-smoothing: antialiased;
    }
    .btn-hover-effect {
      transition: all 200ms ease-out;
    }
    .btn-hover-effect:hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(16, 185, 129, 0.3);
    }
    .card-surface {
      background: #FFFFFF;
      border: 1px solid #E2E8F0;
      border-radius: 14px;
      box-shadow: var(--shadow-soft);
      transition: all 250ms ease;
    }
    .card-surface:hover {
      box-shadow: var(--shadow-hover);
      border-color: #CBD5E1;
      transform: translateY(-2px);
    }
    .glass-nav {
      background: rgba(255, 255, 255, 0.88);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
    }
    .typing-cursor::after {
      content: '|';
      animation: blink 1s infinite;
    }
    @keyframes blink {
      0%, 100% { opacity: 1; }
      50% { opacity: 0; }
    }