/* roulang page: index */
:root {
    --primary: #0a2d5c;
    --primary-2: #123b66;
    --accent: #2e8fff;
    --accent-2: #00c6fb;
    --surface: #ffffff;
    --bg: #f4f7fb;
    --text: #16222e;
    --text-weak: #57687a;
    --text-faint: #8a9aa8;
    --border: #e2e8f0;
    --radius: 14px;
    --radius-lg: 20px;
    --shadow-sm: 0 2px 12px rgba(10,40,70,0.05);
    --shadow-md: 0 10px 30px rgba(10,40,70,0.07);
    --shadow-lg: 0 20px 48px rgba(10,40,70,0.13);
    --section-gap: 104px;
    --section-gap-md: 72px;
  }

  * { box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  body { margin: 0; letter-spacing: 0.01em; }
  img { max-width: 100%; display: block; }
  a { text-decoration: none; color: inherit; }
  button { font: inherit; cursor: pointer; }

  .container-x { max-width: 1280px; margin-left: auto; margin-right: auto; padding-left: 1.25rem; padding-right: 1.25rem; }
  @media (min-width: 640px) { .container-x { padding-left: 2rem; padding-right: 2rem; } }

  section { position: relative; }

  .section-gap { padding-top: var(--section-gap); padding-bottom: var(--section-gap); }
  @media (max-width: 768px) { .section-gap { padding-top: var(--section-gap-md); padding-bottom: var(--section-gap-md); } }

  .section-label {
    display: inline-flex; align-items: center; gap: 8px;
    font-size: 13px; font-weight: 600; letter-spacing: 0.12em;
    color: var(--accent); background: rgba(46, 143, 255, 0.08);
    padding: 6px 16px; border-radius: 999px; text-transform: uppercase;
  }

  .section-title { font-size: clamp(1.6rem, 3vw, 2.35rem); font-weight: 800; line-height: 1.25; color: var(--text); }
  .section-sub { font-size: 1.05rem; line-height: 1.75; color: var(--text-weak); max-width: 620px; }

  /* ---- Buttons ---- */
  .btn-primary {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    background: linear-gradient(135deg, #2e8fff 0%, #00a6e8 100%);
    color: #fff; font-weight: 600; font-size: 15px;
    padding: 12px 28px; border-radius: 999px;
    box-shadow: 0 4px 18px rgba(46, 143, 255, 0.28);
    transition: all 0.25s ease;
    border: none; line-height: 1.2;
  }
  .btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 28px rgba(46, 143, 255, 0.38); }
  .btn-primary:active { transform: translateY(0); box-shadow: 0 3px 12px rgba(46, 143, 255, 0.3); }
  .btn-primary:focus-visible { outline: 3px solid rgba(46, 143, 255, 0.4); outline-offset: 3px; }

  .btn-outline {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    background: rgba(255,255,255,0.06); color: #fff; font-weight: 600; font-size: 15px;
    padding: 12px 28px; border-radius: 999px;
    border: 1.5px solid rgba(255,255,255,0.35);
    backdrop-filter: blur(4px);
    transition: all 0.25s ease; line-height: 1.2;
  }
  .btn-outline:hover { background: rgba(255,255,255,0.14); border-color: rgba(255,255,255,0.7); transform: translateY(-2px); }
  .btn-outline:active { transform: translateY(0); }
  .btn-outline:focus-visible { outline: 3px solid rgba(255,255,255,0.35); outline-offset: 3px; }

  /* ---- Nav ---- */
  .nav-chip {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 8px 18px; border-radius: 999px;
    font-size: 14px; font-weight: 500; color: #3d4f62;
    border: 1px solid transparent;
    transition: all 0.2s ease; white-space: nowrap;
  }
  .nav-chip:hover { background: rgba(46, 143, 255, 0.08); color: var(--accent); }
  .nav-chip.active { background: linear-gradient(135deg, rgba(46,143,255,0.14), rgba(0,198,251,0.12)); color: #1555af; border-color: rgba(46,143,255,0.25); font-weight: 600; }
  .nav-chip:focus-visible { outline: 3px solid rgba(46, 143, 255, 0.35); outline-offset: 2px; }

  /* ---- Cards ---- */
  .card-base {
    background: var(--surface); border-radius: var(--radius);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
  }
  .card-base:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); border-color: rgba(46, 143, 255, 0.25); }

  .category-card { overflow: hidden; position: relative; }
  .category-card .card-img { height: 180px; overflow: hidden; }
  .category-card .card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s ease; }
  .category-card:hover .card-img img { transform: scale(1.06); }
  .category-card .card-body { padding: 1.75rem 1.6rem 1.9rem; }

  /* ---- News list ---- */
  .news-item {
    padding: 1.35rem 1.5rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
    transition: all 0.25s ease;
  }
  .news-item:hover { border-color: rgba(46, 143, 255, 0.3); box-shadow: var(--shadow-md); transform: translateY(-2px); }
  .news-item + .news-item { margin-top: 0.85rem; }

  /* ---- Badge ---- */
  .badge {
    display: inline-flex; align-items: center; gap: 6px;
    font-size: 12px; font-weight: 600; color: #1555af;
    background: rgba(46, 143, 255, 0.1);
    padding: 4px 12px; border-radius: 999px;
    white-space: nowrap;
  }

  /* ---- Process steps ---- */
  .step-card {
    position: relative; padding: 2rem 1.5rem 1.75rem;
    background: var(--surface); border: 1px solid var(--border);
    border-radius: var(--radius); box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
  }
  .step-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); }
  .step-num {
    width: 46px; height: 46px; border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    background: linear-gradient(135deg, #2e8fff, #00c6fb);
    color: #fff; font-weight: 700; font-size: 18px;
    box-shadow: 0 6px 16px rgba(46, 143, 255, 0.3);
    margin-bottom: 1rem;
  }

  /* ---- Service cards ---- */
  .service-card {
    padding: 1.9rem 1.6rem; background: var(--surface);
    border: 1px solid var(--border); border-radius: var(--radius);
    box-shadow: var(--shadow-sm); transition: all 0.3s ease;
  }
  .service-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-4px); border-color: rgba(46, 143, 255, 0.22); }
  .service-icon {
    width: 54px; height: 54px; border-radius: 14px;
    background: linear-gradient(135deg, rgba(46,143,255,0.12), rgba(0,198,251,0.12));
    display: flex; align-items: center; justify-content: center;
    color: var(--accent); font-size: 22px; margin-bottom: 1.1rem;
  }

  /* ---- FAQ ---- */
  .faq-item { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); overflow: hidden; transition: all 0.25s ease; }
  .faq-item + .faq-item { margin-top: 0.8rem; }
  .faq-item.open { border-color: rgba(46, 143, 255, 0.3); box-shadow: var(--shadow-md); }
  .faq-q {
    width: 100%; display: flex; align-items: center; justify-content: space-between; gap: 12px;
    padding: 1.2rem 1.5rem; background: transparent; border: none; text-align: left;
    font-size: 15.5px; font-weight: 600; color: var(--text);
    transition: color 0.2s;
  }
  .faq-q:hover { color: var(--accent); }
  .faq-q .fa { transition: transform 0.3s ease; color: var(--text-faint); font-size: 14px; flex-shrink: 0; }
  .faq-item.open .faq-q .fa { transform: rotate(180deg); color: var(--accent); }
  .faq-a { max-height: 0; overflow: hidden; transition: max-height 0.35s ease; }
  .faq-a-inner { padding: 0 1.5rem 1.4rem; font-size: 14.5px; line-height: 1.75; color: var(--text-weak); }

  /* ---- Footer ---- */
  .footer-link { color: rgba(255,255,255,0.6); font-size: 14px; line-height: 2.3; transition: color 0.2s; }
  .footer-link:hover { color: #fff; }

  /* ---- Mobile menu ---- */
  .mobile-menu { max-height: 0; overflow: hidden; transition: max-height 0.35s ease; }
  .mobile-menu.open { max-height: 420px; }

  /* ---- Reveal animation ---- */
  .reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.7s ease, transform 0.7s ease; }
  .reveal.visible { opacity: 1; transform: translateY(0); }

  /* ---- Custom scrollbar ---- */
  ::-webkit-scrollbar { width: 8px; height: 8px; }
  ::-webkit-scrollbar-track { background: #f0f2f5; }
  ::-webkit-scrollbar-thumb { background: #b9c4d0; border-radius: 10px; }
  ::-webkit-scrollbar-thumb:hover { background: #95a3b5; }

  /* ---- Focus visible accessibility ---- */
  a:focus-visible, button:focus-visible { outline: 3px solid rgba(46, 143, 255, 0.45); outline-offset: 2px; border-radius: 4px; }

/* roulang page: category1 */
:root {
        --brand-500: #267df5;
        --brand-600: #1560d4;
        --brand-900: #12346c;
        --ink: #0f172a;
        --ink-soft: #334155;
        --ink-faint: #94a3b8;
        --border: #e2e8f0;
        --radius: 16px;
        --radius-sm: 12px;
        --shadow-card: 0 1px 3px rgba(15,23,42,.06), 0 4px 16px rgba(15,23,42,.06);
        --shadow-lift: 0 2px 6px rgba(15,23,42,.08), 0 14px 32px rgba(15,23,42,.12);
    }

    html {
        scroll-behavior: smooth;
    }

    body {
        font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
        color: #0f172a;
        background-color: #f8fafc;
        line-height: 1.6;
        -webkit-font-smoothing: antialiased;
    }

    *, *::before, *::after {
        box-sizing: border-box;
    }

    img {
        max-width: 100%;
        display: block;
    }

    a {
        text-decoration: none;
        color: inherit;
    }

    button {
        cursor: pointer;
        border: none;
        background: none;
        font: inherit;
    }

    .container-x {
        width: 100%;
        max-width: 1200px;
        margin-left: auto;
        margin-right: auto;
        padding-left: 1.25rem;
        padding-right: 1.25rem;
    }

    @media (min-width: 1024px) {
        .container-x {
            padding-left: 2rem;
            padding-right: 2rem;
        }
    }

    .nav-chip {
        display: inline-flex;
        align-items: center;
        gap: 0.375rem;
        padding: 0.5rem 0.875rem;
        border-radius: 9999px;
        font-size: 0.875rem;
        font-weight: 500;
        color: #334155;
        transition: all 0.25s ease;
        white-space: nowrap;
    }

    .nav-chip:hover {
        color: #12346c;
        background-color: #eff8ff;
    }

    .nav-chip.active {
        background-color: #eff8ff;
        color: #12346c;
        font-weight: 600;
        box-shadow: inset 0 0 0 1px #b8dcff;
    }

    .nav-chip:focus-visible {
        outline: 2px solid #267df5;
        outline-offset: 2px;
    }

    .btn-primary {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        gap: 0.5rem;
        padding: 0.75rem 1.75rem;
        border-radius: 12px;
        font-size: 0.925rem;
        font-weight: 600;
        color: #fff;
        background: linear-gradient(135deg, #267df5 0%, #06b6d4 100%);
        box-shadow: 0 8px 24px rgba(37, 125, 245, 0.28);
        transition: all 0.25s ease;
    }

    .btn-primary:hover {
        transform: translateY(-2px);
        box-shadow: 0 12px 32px rgba(37, 125, 245, 0.38);
    }

    .btn-primary:active {
        transform: translateY(0);
        box-shadow: 0 4px 16px rgba(37, 125, 245, 0.24);
    }

    .btn-primary:focus-visible {
        outline: 3px solid rgba(37, 125, 245, 0.4);
        outline-offset: 3px;
    }

    .btn-secondary {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        gap: 0.5rem;
        padding: 0.75rem 1.75rem;
        border-radius: 12px;
        font-size: 0.925rem;
        font-weight: 600;
        color: #12346c;
        background: #eff8ff;
        border: 1px solid #b8dcff;
        transition: all 0.25s ease;
    }

    .btn-secondary:hover {
        background: #dceeff;
        border-color: #84c2ff;
    }

    .mobile-menu {
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.35s ease;
    }

    .mobile-menu.open {
        max-height: 400px;
    }

    .badge {
        display: inline-flex;
        align-items: center;
        gap: 0.375rem;
        padding: 0.25rem 0.75rem;
        border-radius: 9999px;
        font-size: 0.75rem;
        font-weight: 600;
        letter-spacing: 0.02em;
    }

    .card {
        border-radius: var(--radius);
        background: #fff;
        border: 1px solid #eef2f7;
        box-shadow: var(--shadow-card);
        transition: all 0.3s ease;
    }

    .card:hover {
        box-shadow: var(--shadow-lift);
        transform: translateY(-4px);
        border-color: #dceeff;
    }

    .step-card {
        position: relative;
        border-radius: var(--radius);
        background: #fff;
        border: 1px solid #eef2f7;
        box-shadow: var(--shadow-card);
        transition: all 0.3s ease;
    }

    .step-card:hover {
        box-shadow: var(--shadow-lift);
        transform: translateY(-3px);
    }

    .tag {
        display: inline-flex;
        align-items: center;
        gap: 0.375rem;
        padding: 0.375rem 0.875rem;
        border-radius: 9999px;
        font-size: 0.8125rem;
        font-weight: 500;
        background: #f1f5f9;
        color: #334155;
        transition: all 0.2s ease;
    }

    .tag:hover {
        background: #dceeff;
        color: #12346c;
    }

    .faq-item {
        border: 1px solid #e2e8f0;
        border-radius: 14px;
        background: #fff;
        padding: 1.25rem 1.5rem;
        transition: all 0.25s ease;
    }

    .faq-item:hover {
        border-color: #b8dcff;
        box-shadow: var(--shadow-card);
    }

    .footer-link {
        color: rgba(255, 255, 255, 0.55);
        font-size: 0.875rem;
        transition: all 0.2s ease;
        padding: 0.25rem 0;
        display: inline-block;
    }

    .footer-link:hover {
        color: #fff;
        padding-left: 4px;
    }

    .hero-back {
        background-image: linear-gradient(135deg, rgba(11, 32, 69, 0.92) 0%, rgba(18, 52, 108, 0.82) 45%, rgba(37, 125, 245, 0.55) 100%), url('/assets/images/backpic/back-1.png');
        background-size: cover;
        background-position: center;
        background-repeat: no-repeat;
    }

    .section-back-light {
        background-image: url('/assets/images/backpic/back-2.png');
        background-size: cover;
        background-position: center;
        background-repeat: no-repeat;
        background-color: #f8fafc;
    }

    .tech-grid {
        display: grid;
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    @media (min-width: 768px) {
        .tech-grid {
            grid-template-columns: repeat(2, 1fr);
        }
    }

    @media (min-width: 1024px) {
        .tech-grid {
            grid-template-columns: repeat(3, 1fr);
        }
    }

    .steps-grid {
        display: grid;
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    @media (min-width: 768px) {
        .steps-grid {
            grid-template-columns: repeat(2, 1fr);
        }
    }

    @media (min-width: 1024px) {
        .steps-grid {
            grid-template-columns: repeat(4, 1fr);
        }
    }

    .list-check li {
        position: relative;
        padding-left: 1.75rem;
        margin-bottom: 0.625rem;
        font-size: 0.9375rem;
        color: #334155;
    }

    .list-check li::before {
        content: "\f00c";
        font-family: "Font Awesome 6 Free";
        font-weight: 900;
        position: absolute;
        left: 0;
        top: 0;
        color: #267df5;
        font-size: 0.875rem;
    }

/* roulang page: article */
:root {
    --brand-50: #ecfdf8; --brand-100: #d1faf0; --brand-200: #a7f3e4;
    --brand-300: #6ee7d0; --brand-400: #34d3b8; --brand-500: #10b9a0;
    --brand-600: #05968a; --brand-700: #047869; --brand-800: #065f52;
    --brand-900: #064e45; --brand-950: #022c26;
    --ink-900: #0f172a; --ink-700: #334155; --ink-500: #64748b; --ink-faint: #94a3b8;
    --shadow-soft: 0 18px 40px -24px rgba(2, 44, 38, .18);
    --shadow-card: 0 14px 30px -18px rgba(2, 44, 38, .16);
    --radius-xl: 1.25rem;
    --radius-lg: 1rem;
  }

  html { scroll-behavior: smooth; }
  body { font-family: 'Inter', system-ui, -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif; background: #f8fafc; color: var(--ink-900); -webkit-font-smoothing: antialiased; }

  .container-x { max-width: 72rem; margin-inline: auto; padding-inline: 1.25rem; }
  @media (min-width: 768px) { .container-x { padding-inline: 2rem; } }

  .nav-chip {
    display: inline-flex; align-items: center; gap: .4rem;
    padding: .5rem .95rem; border-radius: 999px; font-weight: 600;
    font-size: .9rem; color: var(--ink-700); transition: all .2s ease;
  }
  .nav-chip:hover { background: #f1f5f9; color: var(--brand-800); }
  .nav-chip.active { background: var(--brand-50); color: var(--brand-700); box-shadow: inset 0 0 0 1px rgba(16, 185, 160, .22); }
  .nav-chip:focus-visible { outline: 3px solid rgba(16, 185, 160, .35); outline-offset: 2px; }

  .btn-primary {
    display: inline-flex; align-items: center; justify-content: center; gap: .5rem;
    border-radius: .85rem; padding: .8rem 1.4rem; font-weight: 600; color: #fff;
    background: linear-gradient(135deg, var(--brand-500), #0891b2);
    box-shadow: 0 12px 24px -10px rgba(16, 185, 160, .42);
    transition: transform .2s, box-shadow .2s, background .2s;
  }
  .btn-primary:hover { transform: translateY(-2px); box-shadow: 0 18px 32px -12px rgba(16, 185, 160, .5); }
  .btn-primary:active { transform: translateY(0); }
  .btn-primary:focus-visible { outline: 3px solid rgba(16, 185, 160, .4); outline-offset: 3px; }

  .btn-outline {
    display: inline-flex; align-items: center; justify-content: center; gap: .45rem;
    border: 1px solid var(--brand-300); background: #fff; color: var(--brand-700);
    border-radius: .8rem; padding: .7rem 1.2rem; font-weight: 600; transition: all .2s;
  }
  .btn-outline:hover { background: var(--brand-50); border-color: var(--brand-400); transform: translateY(-1px); }
  .btn-outline:focus-visible { outline: 3px solid rgba(16, 185, 160, .25); outline-offset: 2px; }

  .btn-white {
    display: inline-flex; align-items: center; justify-content: center; gap: .45rem;
    background: #fff; color: var(--brand-900); border-radius: .85rem;
    padding: .8rem 1.4rem; font-weight: 700; box-shadow: 0 14px 30px -12px rgba(2, 44, 38, .45);
    transition: transform .2s, box-shadow .2s;
  }
  .btn-white:hover { transform: translateY(-2px); box-shadow: 0 20px 36px -14px rgba(2, 44, 38, .55); }

  .btn-ghost-white {
    display: inline-flex; align-items: center; justify-content: center; gap: .45rem;
    border: 1px solid rgba(255, 255, 255, .4); color: #fff; border-radius: .85rem;
    padding: .8rem 1.3rem; font-weight: 600; transition: all .2s;
  }
  .btn-ghost-white:hover { background: rgba(255, 255, 255, .1); border-color: rgba(255, 255, 255, .7); }

  .banner-hero {
    background:
      linear-gradient(115deg, rgba(2, 44, 34, .95) 0%, rgba(4, 120, 105, .86) 55%, rgba(8, 145, 178, .74) 100%),
      url('/assets/images/backpic/back-1.png') center / cover no-repeat;
  }

  .cta-section {
    background:
      linear-gradient(120deg, rgba(2, 44, 34, .97) 0%, rgba(5, 78, 69, .9) 55%, rgba(8, 145, 178, .82) 100%),
      url('/assets/images/backpic/back-3.png') center / cover no-repeat;
  }

  .module-tag {
    display: inline-flex; align-items: center; gap: .45rem;
    padding: .4rem .9rem; border-radius: 999px;
    background: rgba(255, 255, 255, .14); border: 1px solid rgba(255, 255, 255, .18);
    color: #fff; font-size: .82rem; font-weight: 600; letter-spacing: .04em;
  }

  .card-hover { transition: transform .25s ease, box-shadow .25s ease; }
  .card-hover:hover { transform: translateY(-5px); box-shadow: 0 24px 40px -20px rgba(2, 44, 38, .2); }

  .side-card {
    background: #fff; border-radius: var(--radius-xl);
    border: 1px solid rgba(226, 232, 240, .8); padding: 1.5rem;
    box-shadow: var(--shadow-soft);
  }
  .side-title {
    font-size: 1.05rem; font-weight: 700; color: var(--ink-900);
    margin-bottom: 1rem; display: flex; align-items: center; gap: .45rem;
  }

  .article-content { font-size: 1.06rem; line-height: 1.9; color: var(--ink-700); }
  .article-content h1, .article-content h2, .article-content h3, .article-content h4, .article-content h5 {
    font-weight: 800; color: var(--ink-900); margin-top: 1.9rem; margin-bottom: .85rem; line-height: 1.4;
  }
  .article-content h1 { font-size: 1.7rem; }
  .article-content h2 { font-size: 1.45rem; }
  .article-content h3 { font-size: 1.2rem; }
  .article-content p { margin-bottom: 1.2rem; }
  .article-content a { color: var(--brand-600); text-decoration: underline; text-underline-offset: 3px; }
  .article-content a:hover { color: var(--brand-800); }
  .article-content ul, .article-content ol { padding-left: 1.5rem; margin-bottom: 1.25rem; }
  .article-content ul { list-style: disc; }
  .article-content ol { list-style: decimal; }
  .article-content li { margin-bottom: .45rem; }
  .article-content img { max-width: 100%; height: auto; border-radius: var(--radius-lg); margin-block: 1.4rem; box-shadow: var(--shadow-soft); }
  .article-content blockquote {
    border-left: 3px solid var(--brand-400); background: var(--brand-50);
    padding: 1rem 1.2rem; border-radius: 0 .75rem .75rem 0;
    margin-bottom: 1.2rem; color: var(--ink-700);
  }
  .article-content table { width: 100%; border-collapse: collapse; margin-block: 1.4rem; }
  .article-content th, .article-content td { border: 1px solid #e2e8f0; padding: .75rem; font-size: .95rem; }
  .article-content th { background: #f1f5f9; font-weight: 700; color: var(--ink-900); }

  .share-btn {
    display: inline-flex; align-items: center; gap: .4rem;
    padding: .5rem .95rem; border-radius: 999px;
    border: 1px solid #e2e8f0; background: #fff; color: #475569;
    font-size: .85rem; font-weight: 500; transition: all .2s;
  }
  .share-btn:hover { border-color: var(--brand-300); color: var(--brand-700); background: var(--brand-50); }
  .share-btn:focus-visible { outline: 3px solid rgba(16, 185, 160, .25); outline-offset: 2px; }

  .breadcrumb-sep { margin: 0 .45rem; color: rgba(255, 255, 255, .45); }

  .footer-link { font-size: .9rem; color: rgba(255, 255, 255, .5); transition: color .2s, padding-left .2s; }
  .footer-link:hover { color: #fff; padding-left: 4px; }

  .mobile-menu { display: none; }
  .mobile-menu.open { display: block; }

  @media (max-width: 640px) {
    .article-content { font-size: .98rem; }
    .container-x { padding-inline: 1rem; }
  }

/* roulang page: category2 */
:root {
    --brand-50: #f0f7ff;
    --brand-100: #e0efff;
    --brand-200: #b8dcff;
    --brand-300: #7ac1ff;
    --brand-400: #36a1ff;
    --brand-500: #0f7ae8;
    --brand-600: #005bb5;
    --brand-700: #004a94;
    --brand-800: #003d7a;
    --brand-900: #062d54;
    --brand-950: #041f3a;
    --ink: #1e293b;
    --ink-faint: #64748b;
    --bg-soft: #f8fafc;
    --border: #e2e8f0;
    --radius-card: 1rem;
    --radius-btn: 0.75rem;
    --shadow-card: 0 18px 40px -20px rgba(2, 32, 71, 0.16);
    --shadow-hover: 0 24px 50px -22px rgba(2, 32, 71, 0.22);
  }

  html { scroll-behavior: smooth; }

  body {
    font-family: 'Inter', system-ui, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    color: var(--ink);
    background: #ffffff;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
  }

  .container-x {
    width: 100%;
    max-width: 1200px;
    margin-inline: auto;
    padding-inline: 1rem;
  }

  @media (min-width: 768px) {
    .container-x { padding-inline: 2rem; }
  }

  .nav-chip {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.55rem 1rem;
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--ink-faint);
    transition: all 0.2s ease;
    white-space: nowrap;
  }

  .nav-chip:hover {
    background: var(--brand-50);
    color: var(--brand-600);
  }

  .nav-chip.active {
    background: var(--brand-100);
    color: var(--brand-700);
    font-weight: 600;
    box-shadow: inset 0 0 0 1px rgba(15, 122, 232, 0.12);
  }

  .btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-btn);
    background: linear-gradient(135deg, #0f7ae8 0%, #06b6d4 100%);
    color: #ffffff;
    font-weight: 600;
    font-size: 0.9rem;
    box-shadow: 0 10px 22px -10px rgba(15, 122, 232, 0.55);
    transition: all 0.2s ease;
    outline: none;
  }

  .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 16px 30px -12px rgba(15, 122, 232, 0.55);
  }

  .btn-primary:focus-visible {
    outline: 3px solid rgba(15, 122, 232, 0.4);
    outline-offset: 2px;
  }

  .btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-btn);
    background: rgba(255, 255, 255, 0.12);
    color: #ffffff;
    border: 1px solid rgba(255, 255, 255, 0.3);
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.2s ease;
    outline: none;
  }

  .btn-secondary:hover {
    background: rgba(255, 255, 255, 0.22);
  }

  .btn-secondary:focus-visible {
    outline: 3px solid rgba(255, 255, 255, 0.4);
    outline-offset: 2px;
  }

  .badge {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.3rem 0.75rem;
    border-radius: 999px;
    background: var(--brand-100);
    color: var(--brand-700);
  }

  .footer-link {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.875rem;
    transition: all 0.2s ease;
    display: inline-block;
  }

  .footer-link:hover {
    color: #ffffff;
    padding-left: 4px;
  }

  .card-hover {
    transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
  }

  .card-hover:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
  }

  .section-title {
    font-size: 1.875rem;
    line-height: 1.3;
    font-weight: 800;
    letter-spacing: -0.02em;
    color: var(--brand-950);
  }

  .section-subtitle {
    font-size: 1rem;
    color: var(--ink-faint);
    max-width: 640px;
    line-height: 1.8;
  }

  @media (max-width: 767px) {
    .section-title { font-size: 1.5rem; }
  }

  .faq-item {
    border: 1px solid var(--border);
    border-radius: 1rem;
    background: #ffffff;
    padding: 1.25rem 1.5rem;
    transition: box-shadow 0.2s ease, border-color 0.2s ease;
  }

  .faq-item:hover {
    border-color: var(--brand-200);
  }

  .faq-item[open] {
    box-shadow: 0 18px 36px -22px rgba(2, 32, 71, 0.18);
    border-color: var(--brand-200);
  }

  .faq-item summary {
    cursor: pointer;
    font-weight: 600;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    color: var(--brand-950);
  }

  .faq-item summary::-webkit-details-marker {
    display: none;
  }

  .faq-item summary .icon {
    width: 2rem;
    height: 2rem;
    border-radius: 999px;
    background: var(--brand-50);
    color: var(--brand-600);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: transform 0.3s ease, background 0.3s ease;
  }

  .faq-item[open] summary .icon {
    transform: rotate(180deg);
    background: var(--brand-100);
  }

  .faq-item .answer {
    color: var(--ink-faint);
    font-size: 0.9375rem;
    line-height: 1.85;
    padding-top: 0.75rem;
  }

  .hero-overlay {
    background: linear-gradient(120deg, rgba(4, 31, 58, 0.94) 0%, rgba(6, 45, 84, 0.82) 38%, rgba(6, 45, 84, 0.4) 100%);
  }

  .stat-card {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 1.25rem;
    padding: 2rem 1.5rem;
    backdrop-filter: blur(6px);
    text-align: center;
  }

  .step-card {
    position: relative;
    background: #ffffff;
    border: 1px solid var(--border);
    border-radius: 1.25rem;
    padding: 1.75rem;
    box-shadow: var(--shadow-card);
  }

  .step-card .step-num {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 0.9rem;
    background: linear-gradient(135deg, #0f7ae8, #06b6d4);
    color: #fff;
    font-weight: 700;
    font-size: 0.9rem;
    box-shadow: 0 8px 18px -8px rgba(15, 122, 232, 0.6);
    margin-bottom: 1rem;
  }

  .breadcrumb-item {
    color: rgba(255, 255, 255, 0.55);
    font-size: 0.8rem;
  }

  .breadcrumb-item a {
    color: rgba(255, 255, 255, 0.75);
    transition: color 0.2s;
  }

  .breadcrumb-item a:hover {
    color: #ffffff;
  }

  .breadcrumb-sep {
    color: rgba(255, 255, 255, 0.35);
    margin: 0 0.5rem;
    font-size: 0.75rem;
  }

  .mobile-menu {
    transition: all 0.25s ease;
  }

  .mobile-menu.hidden {
    display: none;
  }

  .img-shadow {
    box-shadow: 0 24px 48px -24px rgba(2, 32, 71, 0.28);
    border-radius: 1.25rem;
  }

  .cta-panel {
    background:
      radial-gradient(circle at 15% 20%, rgba(15, 122, 232, 0.32), transparent 45%),
      radial-gradient(circle at 85% 85%, rgba(6, 182, 212, 0.28), transparent 45%),
      linear-gradient(120deg, #041f3a, #062d54);
    border-radius: 1.75rem;
    overflow: hidden;
  }

/* roulang page: category3 */
:root {
            --brand-50: #eef7fd;
            --brand-100: #d9eefb;
            --brand-500: #2b8ae0;
            --brand-700: #1b5a9f;
            --brand-900: #0e2f55;
            --brand-950: #0a203c;
            --ink: #1e293b;
            --ink-soft: #475569;
            --ink-faint: #94a3b8;
            --bg-soft: #f8fafc;
            --border: #e2e8f0;
            --radius: 1rem;
            --radius-lg: 1.5rem;
            --shadow: 0 4px 24px rgba(15, 47, 76, 0.08);
            --shadow-hover: 0 18px 40px rgba(15, 47, 76, 0.14);
        }

        * {
            box-sizing: border-box;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
            color: var(--ink);
            background-color: #f9fbfd;
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
            overflow-x: hidden;
        }

        .container-x {
            max-width: 1200px;
            margin: 0 auto;
            padding-left: 1.5rem;
            padding-right: 1.5rem;
        }

        @media (min-width: 1024px) {
            .container-x {
                padding-left: 2rem;
                padding-right: 2rem;
            }
        }

        a,
        button,
        input,
        select,
        textarea {
            transition: all 0.25s ease;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        .nav-chip {
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            padding: 0.55rem 1rem;
            border-radius: 9999px;
            font-size: 0.875rem;
            font-weight: 500;
            color: var(--ink-soft);
            background: transparent;
            border: 1px solid transparent;
        }

        .nav-chip:hover {
            background: var(--brand-50);
            color: var(--brand-700);
        }

        .nav-chip.active {
            background: var(--brand-50);
            color: var(--brand-900);
            border-color: var(--brand-100);
            font-weight: 700;
            box-shadow: 0 2px 8px rgba(43, 138, 224, 0.08);
        }

        .nav-chip:focus-visible,
        .btn-primary:focus-visible,
        .footer-link:focus-visible,
        a:focus-visible,
        button:focus-visible,
        input:focus-visible {
            outline: 2px solid var(--brand-500);
            outline-offset: 2px;
        }

        .btn-primary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            background: linear-gradient(135deg, #2b8ae0, #22d3ee);
            color: #fff;
            font-weight: 600;
            font-size: 0.875rem;
            padding: 0.75rem 1.5rem;
            border-radius: 9999px;
            box-shadow: 0 8px 20px rgba(43, 138, 224, 0.25);
            border: none;
            cursor: pointer;
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 12px 28px rgba(43, 138, 224, 0.32);
        }

        .btn-primary:active {
            transform: translateY(0);
            box-shadow: 0 4px 12px rgba(43, 138, 224, 0.2);
        }

        .btn-outline {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            background: #fff;
            color: var(--brand-700);
            font-weight: 600;
            font-size: 0.875rem;
            padding: 0.75rem 1.5rem;
            border-radius: 9999px;
            border: 1.5px solid var(--brand-100);
            box-shadow: 0 2px 10px rgba(15, 47, 76, 0.04);
            cursor: pointer;
        }

        .btn-outline:hover {
            border-color: var(--brand-500);
            background: var(--brand-50);
            transform: translateY(-2px);
        }

        .btn-outline:active {
            transform: translateY(0);
        }

        .badge {
            display: inline-flex;
            align-items: center;
            gap: 0.35rem;
            font-size: 0.75rem;
            font-weight: 600;
            padding: 0.28rem 0.8rem;
            border-radius: 9999px;
            background: var(--brand-50);
            color: var(--brand-700);
            border: 1px solid var(--brand-100);
            letter-spacing: 0.02em;
        }

        .badge-cyan {
            background: #ecfeff;
            color: #0e7490;
            border-color: #a5f3fc;
        }

        .badge-violet {
            background: #f5f3ff;
            color: #6d28d9;
            border-color: #ddd6fe;
        }

        .badge-amber {
            background: #fffbeb;
            color: #b45309;
            border-color: #fde68a;
        }

        .card {
            background: #fff;
            border: 1px solid var(--border);
            border-radius: var(--radius-lg);
            box-shadow: var(--shadow);
            transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
            overflow: hidden;
        }

        .card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
            border-color: var(--brand-100);
        }

        .section {
            padding: 5rem 0;
        }

        @media (max-width: 768px) {
            .section {
                padding: 3.5rem 0;
            }
        }

        .section-title {
            font-size: 2.25rem;
            font-weight: 800;
            line-height: 1.2;
            letter-spacing: -0.02em;
            color: var(--brand-950);
        }

        .section-subtitle {
            font-size: 1rem;
            color: var(--ink-soft);
            max-width: 640px;
        }

        .chip-tag {
            display: inline-flex;
            align-items: center;
            gap: 0.35rem;
            font-size: 0.8rem;
            font-weight: 500;
            padding: 0.45rem 1rem;
            border-radius: 9999px;
            background: #fff;
            border: 1px solid var(--border);
            color: var(--ink-soft);
            cursor: pointer;
            transition: all 0.25s ease;
        }

        .chip-tag:hover {
            border-color: var(--brand-500);
            color: var(--brand-700);
            background: var(--brand-50);
        }

        .chip-tag.active {
            background: var(--brand-900);
            border-color: var(--brand-900);
            color: #fff;
            font-weight: 600;
        }

        .timeline-item {
            position: relative;
            padding-left: 2rem;
            padding-bottom: 2.5rem;
            border-left: 2px solid var(--brand-100);
        }

        .timeline-item:last-child {
            border-left-color: transparent;
            padding-bottom: 0;
        }

        .timeline-item::before {
            content: '';
            position: absolute;
            left: -7px;
            top: 4px;
            width: 12px;
            height: 12px;
            border-radius: 9999px;
            background: var(--brand-500);
            border: 2px solid #fff;
            box-shadow: 0 0 0 3px rgba(43, 138, 224, 0.2);
        }

        .feature-card {
            padding: 1.75rem;
            border-radius: var(--radius-lg);
            background: #fff;
            border: 1px solid var(--border);
            box-shadow: var(--shadow);
            transition: all 0.3s ease;
            height: 100%;
        }

        .feature-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
            border-color: var(--brand-100);
        }

        .feature-icon {
            width: 52px;
            height: 52px;
            border-radius: 16px;
            display: flex;
            align-items: center;
            justify-content: center;
            background: linear-gradient(135deg, var(--brand-500), #22d3ee);
            color: #fff;
            font-size: 1.2rem;
            box-shadow: 0 8px 20px rgba(43, 138, 224, 0.2);
            margin-bottom: 1.25rem;
        }

        .mobile-menu {
            display: none;
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.4s ease;
        }

        .mobile-menu.open {
            display: block;
            max-height: 500px;
        }

        @media (max-width: 1023px) {
            .nav-desktop {
                display: none;
            }
        }

        .footer-link {
            color: rgba(255, 255, 255, 0.55);
            font-size: 0.875rem;
            padding: 0.2rem 0;
            display: inline-block;
            transition: color 0.25s ease, padding-left 0.25s ease;
        }

        .footer-link:hover {
            color: #fff;
            padding-left: 4px;
        }

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease, padding 0.35s ease;
        }

        .faq-item.open .faq-answer {
            max-height: 300px;
            padding-top: 0.75rem;
        }

        .faq-item.open .faq-chevron {
            transform: rotate(180deg);
        }

        .faq-chevron {
            transition: transform 0.35s ease;
        }

        .tag-item {
            display: inline-block;
            font-size: 0.78rem;
            font-weight: 500;
            padding: 0.35rem 0.9rem;
            border-radius: 9999px;
            background: #f1f5f9;
            color: var(--ink-soft);
            transition: all 0.25s ease;
        }

        .tag-item:hover {
            background: var(--brand-50);
            color: var(--brand-700);
        }