/* roulang page: index */
:root {
      --primary-dark: #0B0F19;
      --secondary-dark: #0F172A;
      --brand-blue: #2563EB;
      --brand-teal: #0D9488;
      --accent-amber: #F59E0B;
      --neutral-bg: #F8FAFC;
      --text-main: #0F172A;
      --text-muted: #64748B;
      --border-light: #E2E8F0;
    }
    html {
      scroll-behavior: smooth;
      font-family: system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    }
    body {
      background-color: var(--neutral-bg);
      color: var(--text-main);
      overflow-x: hidden;
      margin: 0;
      padding: 0;
    }
    .custom-shadow {
      box-shadow: 0 10px 30px -5px rgba(15, 23, 42, 0.06), 0 4px 6px -2px rgba(15, 23, 42, 0.03);
    }
    .hero-glow {
      background: radial-gradient(circle at 50% 30%, rgba(37, 99, 235, 0.18) 0%, rgba(13, 148, 136, 0.08) 45%, transparent 70%);
    }
    .gradient-border-card {
      position: relative;
      background: #ffffff;
      border: 1px solid rgba(226, 232, 240, 0.8);
      transition: all 0.25s ease;
    }
    .gradient-border-card:hover {
      transform: translateY(-4px);
      border-color: rgba(37, 99, 235, 0.4);
      box-shadow: 0 18px 35px -8px rgba(37, 99, 235, 0.12);
    }
    .dark-card {
      background: #111827;
      border: 1px solid #1F2937;
    }
    .dark-card:hover {
      border-color: #0D9488;
    }
    :focus-visible {
      outline: 2px solid var(--brand-blue);
      outline-offset: 2px;
    }
    .carousel-slide {
      transition: opacity 0.6s ease-in-out;
    }