/* roulang page: index */
:root {
            --brand: #2E6FE8;
            --brand-dark: #1B4BB5;
            --brand-light: #EAF1FD;
            --accent: #FF6A3D;
            --surface: #F6F8FB;
            --ink: #1E293B;
            --ink-sub: #64748B;
            --line: #E2E8F0;
            --shadow-card: 0 6px 24px rgba(30, 41, 59, 0.06);
            --shadow-card-hover: 0 12px 32px rgba(30, 41, 59, 0.10);
            --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', 'Segoe UI', sans-serif;
        }
        *,
        *::before,
        *::after {
            box-sizing: border-box;
        }
        html {
            scroll-behavior: smooth;
            -webkit-text-size-adjust: 100%;
        }
        body {
            margin: 0;
            font-family: var(--font-sans);
            background: #fff;
            color: var(--ink);
            line-height: 1.6;
        }
        img {
            display: block;
            max-width: 100%;
            background-color: var(--brand-light);
        }
        a {
            color: inherit;
            text-decoration: none;
        }
        button {
            font-family: inherit;
            cursor: pointer;
        }
        input {
            font-family: inherit;
        }
        .scrollbar-hide::-webkit-scrollbar {
            display: none;
        }
        .scrollbar-hide {
            -ms-overflow-style: none;
            scrollbar-width: none;
        }
        .line-clamp-1 {
            display: -webkit-box;
            -webkit-line-clamp: 1;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }
        .line-clamp-2 {
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }
        .line-clamp-3 {
            display: -webkit-box;
            -webkit-line-clamp: 3;
            -webkit-box-orient: vertical;
            overflow: hidden;
        }
        .shadow-card {
            box-shadow: var(--shadow-card);
        }
        .shadow-card-hover {
            box-shadow: var(--shadow-card-hover);
        }
        section[id] {
            scroll-margin-top: 4.5rem;
        }
        .faq-item .faq-a {
            animation: faqFade 0.25s ease;
        }
        @keyframes faqFade {
            from {
                opacity: 0;
                transform: translateY(-4px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }
        :focus-visible {
            outline: 2px solid var(--brand);
            outline-offset: 2px;
        }
        @media (prefers-reduced-motion: reduce) {
            * {
                animation-duration: 0.01ms !important;
                transition-duration: 0.01ms !important;
            }
        }

/* roulang page: category1 */
:root {
            --brand: #2E6FE8;
            --brand-dark: #1B4BB5;
            --brand-light: #EAF1FD;
            --accent: #FF6A3D;
            --bg: #F6F8FB;
            --surface: #FFFFFF;
            --text: #1E293B;
            --text-secondary: #64748B;
            --border: #E2E8F0;
            --shadow-card: 0 6px 24px rgba(30, 41, 59, 0.06);
            --shadow-hover: 0 12px 32px rgba(30, 41, 59, 0.10);
            --radius: 12px;
        }

        * {
            box-sizing: border-box;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
            background-color: var(--bg);
            color: var(--text);
            line-height: 1.6;
            margin: 0;
            -webkit-font-smoothing: antialiased;
        }

        a,
        img,
        button,
        input {
            -webkit-tap-highlight-color: transparent;
        }

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

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

        .container-custom {
            max-width: 1280px;
            margin-left: auto;
            margin-right: auto;
            padding-left: 1rem;
            padding-right: 1rem;
        }

        @media (min-width: 640px) {
            .container-custom {
                padding-left: 1.5rem;
                padding-right: 1.5rem;
            }
        }

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

        .card-default {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            box-shadow: var(--shadow-card);
            transition: box-shadow .3s ease, border-color .3s ease, transform .3s ease;
        }

        .card-default:hover {
            border-color: var(--brand);
            box-shadow: var(--shadow-hover);
            transform: translateY(-3px);
        }

        .card-cat {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: 16px;
            box-shadow: var(--shadow-card);
            transition: box-shadow .3s ease, border-color .3s ease, transform .3s ease;
        }

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

        .btn-primary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 0.75rem 1.75rem;
            border-radius: 10px;
            background: var(--brand);
            color: #fff;
            font-weight: 500;
            font-size: .95rem;
            transition: background .2s ease, transform .2s ease, box-shadow .2s ease;
            box-shadow: 0 4px 12px rgba(46, 111, 232, 0.25);
        }

        .btn-primary:hover {
            background: var(--brand-dark);
            box-shadow: 0 6px 20px rgba(46, 111, 232, 0.35);
        }

        .btn-primary:active {
            transform: scale(0.96);
        }

        .btn-primary:focus-visible {
            outline: none;
            box-shadow: 0 0 0 4px rgba(46, 111, 232, 0.3);
        }

        .btn-secondary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 0.75rem 1.75rem;
            border-radius: 10px;
            background: var(--surface);
            color: var(--text);
            border: 1px solid var(--border);
            font-weight: 500;
            font-size: .95rem;
            transition: border-color .2s ease, color .2s ease, background .2s ease;
        }

        .btn-secondary:hover {
            border-color: var(--brand);
            color: var(--brand);
            background: var(--brand-light);
        }

        .btn-secondary:active {
            transform: scale(0.96);
        }

        .btn-accent {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 0.75rem 1.75rem;
            border-radius: 10px;
            background: var(--accent);
            color: #fff;
            font-weight: 500;
            font-size: .95rem;
            transition: filter .2s ease, transform .2s ease;
            box-shadow: 0 4px 12px rgba(255, 106, 61, 0.25);
        }

        .btn-accent:hover {
            filter: brightness(0.94);
        }

        .btn-accent:active {
            transform: scale(0.96);
        }

        .badge-cat {
            display: inline-flex;
            align-items: center;
            gap: .35rem;
            padding: .25rem .75rem;
            border-radius: 999px;
            background: var(--brand-light);
            color: var(--brand);
            font-size: .75rem;
            font-weight: 700;
            letter-spacing: .02em;
        }

        .badge-accent {
            display: inline-flex;
            align-items: center;
            gap: .35rem;
            padding: .25rem .75rem;
            border-radius: 999px;
            background: rgba(255, 106, 61, 0.12);
            color: var(--accent);
            font-size: .75rem;
            font-weight: 700;
        }

        .section-padding {
            padding-top: 4rem;
            padding-bottom: 4rem;
        }

        @media (min-width: 768px) {
            .section-padding {
                padding-top: 6rem;
                padding-bottom: 6rem;
            }
        }

        .section-title-wrap h2 {
            margin-top: .75rem;
            font-size: 1.75rem;
            line-height: 1.2;
            font-weight: 700;
            letter-spacing: -0.01em;
        }

        @media (min-width: 768px) {
            .section-title-wrap h2 {
                font-size: 2rem;
            }
        }

        .section-title-wrap p {
            margin-top: .75rem;
            color: var(--text-secondary);
            line-height: 1.8;
            font-size: .95rem;
        }

        .list-rank {
            flex: 1;
            min-width: 0;
        }

        .list-rank .num {
            font-size: 1.75rem;
            font-weight: 900;
            color: #CBD5E1;
            width: 2.25rem;
            text-align: center;
            flex-shrink: 0;
            transition: color .2s ease;
        }

        .list-rank .item-rank {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: 14px;
            padding: .85rem 1rem;
            display: flex;
            align-items: center;
            gap: .9rem;
            cursor: pointer;
            transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
        }

        .list-rank .item-rank:hover {
            border-color: var(--brand);
            box-shadow: var(--shadow-card);
            transform: translateX(4px);
        }

        .list-rank .item-rank:hover .num {
            color: var(--accent);
        }

        .list-rank .play-icon {
            width: 2.25rem;
            height: 2.25rem;
            border-radius: 50%;
            background: var(--brand-light);
            color: var(--brand);
            display: flex;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
            transition: background .2s ease, color .2s ease, transform .2s ease;
        }

        .list-rank .item-rank:hover .play-icon {
            background: var(--brand);
            color: #fff;
            transform: scale(1.06);
        }

        .cover-img {
            position: relative;
            overflow: hidden;
        }

        .cover-img img {
            transition: transform .5s ease;
        }

        .cover-img:hover img {
            transform: scale(1.06);
        }

        .cover-overlay {
            position: absolute;
            inset: 0;
            background: linear-gradient(to top, rgba(0, 0, 0, 0.35), transparent 60%);
            opacity: 0;
            transition: opacity .3s ease;
        }

        .cover-img:hover .cover-overlay {
            opacity: 1;
        }

        .faq-item {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: 14px;
            margin-bottom: .75rem;
            overflow: hidden;
            transition: border-color .2s ease, box-shadow .2s ease;
        }

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

        .faq-item[open] {
            border-color: var(--brand);
            box-shadow: var(--shadow-card);
        }

        .faq-item summary {
            list-style: none;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 1rem;
            padding: 1.1rem 1.25rem;
            font-weight: 600;
            font-size: .95rem;
            color: var(--text);
            transition: color .2s ease;
        }

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

        .faq-item summary .chevron {
            width: 1.5rem;
            height: 1.5rem;
            border-radius: 50%;
            background: var(--brand-light);
            display: flex;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
            color: var(--brand);
            transition: transform .3s ease, background .3s ease;
        }

        .faq-item[open] summary {
            color: var(--brand);
        }

        .faq-item[open] summary .chevron {
            transform: rotate(45deg);
            background: var(--brand);
            color: #fff;
        }

        .faq-item .faq-answer {
            padding: 0 1.25rem 1.25rem 1.25rem;
            color: var(--text-secondary);
            line-height: 1.8;
            font-size: .9rem;
        }

        .footer-link {
            transition: color .2s ease;
        }

        .footer-link:hover {
            color: #fff;
        }

        .hide-scrollbar {
            scrollbar-width: none;
            -ms-overflow-style: none;
        }

        .hide-scrollbar::-webkit-scrollbar {
            display: none;
        }

        @media (max-width: 768px) {
            .section-padding {
                padding-top: 2.5rem;
                padding-bottom: 2.5rem;
            }

            .section-title-wrap h2 {
                font-size: 1.45rem;
            }

            .btn-primary,
            .btn-secondary,
            .btn-accent {
                padding: .65rem 1.25rem;
                font-size: .88rem;
            }
        }

/* roulang page: article */
:root {
  --bg: #F6F8FB;
  --surface: #FFFFFF;
  --brand: #2E6FE8;
  --brand-dark: #1B4BB5;
  --brand-light: #EAF1FD;
  --accent: #FF6A3D;
  --text: #1E293B;
  --muted: #64748B;
  --border: #E2E8F0;
  --shadow-card: 0 6px 24px rgba(30, 41, 59, 0.06);
  --shadow-hover: 0 12px 32px rgba(30, 41, 59, 0.10);
}
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
html {
  scroll-behavior: smooth;
}
body {
  font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a {
  color: inherit;
  text-decoration: none;
}
img {
  max-width: 100%;
  display: block;
}
button,
input {
  font-family: inherit;
}
::selection {
  background: rgba(46, 111, 232, 0.18);
}
.shadow-card {
  box-shadow: var(--shadow-card);
}
.no-scrollbar::-webkit-scrollbar {
  display: none;
}
.no-scrollbar {
  -ms-overflow-style: none;
  scrollbar-width: none;
}
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.5rem;
  background: var(--brand);
  color: #fff;
  font-size: 0.875rem;
  font-weight: 600;
  padding: 0.7rem 1.4rem;
  transition: all 0.2s ease;
}
.btn-primary:hover {
  background: var(--brand-dark);
  color: #fff;
}
.btn-primary:focus {
  outline: none;
  box-shadow: 0 0 0 4px rgba(46, 111, 232, 0.3);
}
.btn-primary:active {
  transform: scale(0.95);
}
.btn-outline {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.5rem;
  border: 1px solid #cbd5e1;
  background: #fff;
  color: #334155;
  font-size: 0.875rem;
  font-weight: 600;
  padding: 0.7rem 1.4rem;
  transition: all 0.2s ease;
}
.btn-outline:hover {
  border-color: var(--brand);
  color: var(--brand);
}
.btn-outline:focus {
  outline: none;
  box-shadow: 0 0 0 4px rgba(46, 111, 232, 0.15);
}
.btn-outline:active {
  transform: scale(0.95);
}
.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 1rem;
  box-shadow: var(--shadow-card);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}
.card-hover:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(46, 111, 232, 0.35);
}
.tag {
  display: inline-flex;
  align-items: center;
  padding: 0.35rem 0.85rem;
  border-radius: 9999px;
  background: var(--brand-light);
  color: var(--brand);
  font-size: 0.75rem;
  font-weight: 600;
}
.article-body {
  color: #334155;
}
.article-body p {
  margin-bottom: 1.25rem;
  font-size: 1.0625rem;
  line-height: 1.9;
}
.article-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.4;
  margin: 2.75rem 0 1rem;
  color: var(--text);
}
.article-body h3 {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.5;
  margin: 2.25rem 0 0.75rem;
  color: var(--text);
}
.article-body h4 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin: 1.75rem 0 0.625rem;
  color: var(--text);
}
.article-body a {
  color: var(--brand);
  border-bottom: 1px solid rgba(46, 111, 232, 0.35);
  transition: border-color 0.2s;
}
.article-body a:hover {
  border-color: var(--brand);
}
.article-body ul,
.article-body ol {
  margin: 1.25rem 0;
  padding-left: 1.5rem;
}
.article-body ul {
  list-style: disc;
}
.article-body ol {
  list-style: decimal;
}
.article-body li {
  margin: 0.5rem 0;
  line-height: 1.85;
}
.article-body blockquote {
  margin: 1.75rem 0;
  padding: 1rem 1.5rem;
  border-left: 4px solid var(--brand);
  background: var(--brand-light);
  border-radius: 0 0.75rem 0.75rem 0;
  color: #475569;
}
.article-body blockquote p {
  margin-bottom: 0;
}
.article-body img {
  margin: 1.75rem 0;
  border-radius: 0.75rem;
  box-shadow: var(--shadow-card);
}
.article-body figure {
  margin: 1.75rem 0;
}
.article-body figcaption {
  margin-top: 0.5rem;
  font-size: 0.875rem;
  color: var(--muted);
  text-align: center;
}
.article-body code {
  background: #f1f5f9;
  border: 1px solid #e2e8f0;
  border-radius: 0.375rem;
  padding: 0.2rem 0.45rem;
  font-size: 0.875em;
  color: #334155;
}
.article-body pre {
  background: #0f172a;
  color: #e2e8f0;
  padding: 1.25rem;
  border-radius: 0.75rem;
  overflow-x: auto;
  margin: 1.75rem 0;
  font-size: 0.9rem;
  line-height: 1.7;
}
.article-body pre code {
  background: transparent;
  border: 0;
  padding: 0;
  color: inherit;
}
.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.75rem 0;
  font-size: 0.9375rem;
}
.article-body th,
.article-body td {
  border: 1px solid var(--border);
  padding: 0.625rem 0.875rem;
  text-align: left;
}
.article-body th {
  background: #f8fafc;
  font-weight: 600;
  color: var(--text);
}
.article-body hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}
@media (max-width: 640px) {
  .article-body p {
    font-size: 1rem;
    line-height: 1.85;
  }
  .article-body h2 {
    font-size: 1.3125rem;
  }
  .article-body h3 {
    font-size: 1.125rem;
  }
}