/* roulang page: index */
:root {
      --primary: #1E2229;
      --accent: #E05D38;
      --accent-hover: #C94E2B;
      --secondary: #2E5C56;
      --bg-light: #F9F9F8;
      --bg-deep: #111317;
      --text-main: #111827;
      --text-muted: #4B5563;
      --text-light: #9CA3AF;
      --border-color: #E5E7EB;
      --radius-sm: 8px;
      --radius-md: 12px;
      --shadow-sm: 0 4px 20px -2px rgba(17, 24, 39, 0.05);
      --shadow-lg: 0 12px 30px -4px rgba(17, 24, 39, 0.12);
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    html {
      scroll-behavior: smooth;
      font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
      text-rendering: optimizeLegibility;
      -webkit-font-smoothing: antialiased;
    }
    body {
      background-color: #FFFFFF;
      color: var(--text-main);
      overflow-x: hidden;
      line-height: 1.75;
    }
    .site-container {
      width: 100%;
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 1.25rem;
      padding-right: 1.25rem;
    }
    .section-sp {
      padding-top: 5rem;
      padding-bottom: 5rem;
    }
    @media (min-width: 1024px) {
      .section-sp {
        padding-top: 6.5rem;
        padding-bottom: 6.5rem;
      }
    }
    .btn-brand-accent {
      background-color: var(--accent);
      color: #FFFFFF;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      min-height: 46px;
      padding: 0.65rem 1.6rem;
      font-weight: 500;
      border-radius: var(--radius-sm);
      transition: all 0.25s ease;
      text-decoration: none;
      box-shadow: 0 4px 14px rgba(224, 93, 56, 0.28);
    }
    .btn-brand-accent:hover {
      background-color: var(--accent-hover);
      transform: translateY(-1px);
      box-shadow: 0 6px 18px rgba(224, 93, 56, 0.36);
    }
    .btn-brand-outline {
      background-color: rgba(255, 255, 255, 0.1);
      border: 1px solid rgba(255, 255, 255, 0.35);
      color: #FFFFFF;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      min-height: 46px;
      padding: 0.65rem 1.6rem;
      font-weight: 500;
      border-radius: var(--radius-sm);
      transition: all 0.25s ease;
      backdrop-filter: blur(4px);
    }
    .btn-brand-outline:hover {
      background-color: #FFFFFF;
      color: var(--primary);
    }
    .card-base {
      background-color: #FFFFFF;
      border: 1px solid #F0F0EF;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
    }
    .card-base:hover {
      transform: translateY(-3px);
      box-shadow: var(--shadow-lg);
      border-color: #E2E8F0;
    }
    details summary::-webkit-details-marker {
      display: none;
    }