/* roulang page: index */
:root {
            --brand-primary: #1D4ED8;
            --brand-accent: #0284C7;
            --brand-cyan: #06B6D4;
            --text-main: #0F172A;
            --text-muted: #64748B;
            --bg-base: #F8FAFC;
            --bg-card: #FFFFFF;
            --border-light: #E2E8F0;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-base);
            color: var(--text-main);
            overflow-x: hidden;
        }

        .hero-banner-bg {
            background: linear-gradient(135deg, rgba(248, 250, 252, 0.95) 0%, rgba(241, 245, 249, 0.88) 100%), url('/assets/images/c392846c46e1dad9.png') center/cover no-repeat;
        }

        .dark-philosophy-bg {
            background: radial-gradient(circle at 80% 20%, #1E293B 0%, #0F172A 100%), url('/assets/images/e68162c844f4add6.jpg') center/cover no-repeat;
        }

        .card-transition {
            transition: transform 0.28s ease, box-shadow 0.28s ease, border-color 0.28s ease;
        }

        .card-transition:hover {
            transform: translateY(-4px);
        }

        .accordion-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s cubic-bezier(0, 1, 0, 1);
        }

        .accordion-content.expanded {
            max-height: 400px;
            transition: max-height 0.35s ease-in-out;
        }

        .tab-panel {
            display: none;
        }

        .tab-panel.active {
            display: block;
            animation: fadeIn 0.3s ease-in-out;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(6px); }
            to { opacity: 1; transform: translateY(0); }
        }

/* roulang page: category1 */
:root {
      --brand-primary: #1D4ED8;
      --brand-accent: #0284C7;
      --brand-cyan: #06B6D4;
      --text-main: #0F172A;
      --text-muted: #64748B;
      --bg-base: #F8FAFC;
      --bg-card: #FFFFFF;
      --border-light: #E2E8F0;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
      background-color: var(--bg-base);
      color: var(--text-main);
      overflow-x: hidden;
    }
    .card-transition {
      transition: transform 0.28s ease, box-shadow 0.28s ease, border-color 0.28s ease;
    }
    .card-transition:hover {
      transform: translateY(-4px);
      box-shadow: 0 12px 30px -4px rgba(29, 78, 216, 0.12);
    }
    .filter-btn.active {
      background-color: #1D4ED8;
      color: #FFFFFF;
      border-color: #1D4ED8;
    }