```css
/* ===== 榴莲视频 · 全站样式 ===== */
:root {
    --bg-light: #f9fafb;
    --text-main-light: #17202A;
    --text-secondary-light: #243447;
    --heading-light: #0f1e2e;
    --card-bg-light: #ffffff;
    --nav-bg-light: rgba(255,255,255,0.85);
    --border-light: #d1d9e6;
    --btn-bg-light: #1e3a5f;
    --btn-text-light: #ffffff;
    --link-light: #1e4a7a;
    --footer-bg-light: #0e1a2b;
    --footer-text-light: #e2e8f0;
    --shadow-light: 0 8px 32px rgba(0,0,0,0.06);
    --glass-light: rgba(255,255,255,0.7);

    --bg-dark: #0d1b2a;
    --text-main-dark: #E5E7EB;
    --text-secondary-dark: #cbd5e1;
    --heading-dark: #F8FAFC;
    --card-bg-dark: #1e293b;
    --nav-bg-dark: rgba(30,41,59,0.85);
    --border-dark: #3b4a5f;
    --btn-bg-dark: #3b6ea5;
    --btn-text-dark: #ffffff;
    --link-dark: #8ab4f8;
    --footer-bg-dark: #0a111c;
    --footer-text-dark: #d1d9e6;
    --shadow-dark: 0 8px 32px rgba(0,0,0,0.4);
    --glass-dark: rgba(30,41,59,0.6);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background-color: var(--bg-light);
    color: var(--text-main-light);
    line-height: 1.7;
    transition: background-color 0.3s ease, color 0.3s ease;
    overflow-x: hidden;
    background-image: 
        radial-gradient(circle at 15% 20%, rgba(30,58,95,0.04) 0%, transparent 30%),
        radial-gradient(circle at 85% 70%, rgba(244,197,66,0.05) 0%, transparent 35%);
    background-attachment: fixed;
}

body.dark {
    background-color: var(--bg-dark);
    color: var(--text-main-dark);
    background-image: 
        radial-gradient(circle at 15% 20%, rgba(59,110,165,0.08) 0%, transparent 30%),
        radial-gradient(circle at 85% 70%, rgba(244,197,66,0.03) 0%, transparent 35%);
}

h1, h2, h3, h4, h5 {
    color: var(--heading-light);
    font-weight: 700;
    line-height: 1.3;
    transition: color 0.3s ease;
}

body.dark h1, body.dark h2, body.dark h3, body.dark h4, body.dark h5 {
    color: var(--heading-dark);
}

h1 { font-size: clamp(1.8rem, 4vw, 2.6rem); }
h2 { font-size: clamp(1.4rem, 3vw, 1.9rem); margin-top: 2.2rem; margin-bottom: 1rem; border-left: 6px solid #1e3a5f; padding-left: 0.9rem; letter-spacing: -0.02em; }
body.dark h2 { border-left-color: #6a9bd1; }
h3 { font-size: clamp(1.15rem, 2.5vw, 1.4rem); margin-top: 1.5rem; margin-bottom: 0.6rem; }
h4 { font-size: 1.15rem; color: #1f3a57; }
body.dark h4 { color: #b0c8e0; }
p { color: var(--text-main-light); transition: color 0.3s ease; }
body.dark p { color: var(--text-main-dark); }

a {
    color: var(--link-light);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease, opacity 0.2s ease;
}
body.dark a { color: var(--link-dark); }
a:hover { text-decoration: underline; opacity: 0.85; }

ul, ol { padding-left: 1.5rem; margin: 0.8rem 0; }
li { margin-bottom: 0.4rem; color: var(--text-main-light); transition: color 0.3s ease; }
body.dark li { color: var(--text-main-dark); }

/* ===== 容器 ===== */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
    width: 100%;
}

@media (max-width: 600px) {
    .container { padding: 0 16px; }
}

/* ===== 导航栏 ===== */
.navbar {
    background-color: var(--nav-bg-light);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    box-shadow: 0 1px 0 rgba(0,0,0,0.03), 0 8px 32px rgba(0,0,0,0.04);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 0.7rem 0;
    border-bottom: 1px solid var(--border-light);
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

body.dark .navbar {
    background-color: var(--nav-bg-dark);
    border-bottom-color: rgba(59,74,95,0.4);
    box-shadow: 0 1px 0 rgba(0,0,0,0.2), 0 8px 32px rgba(0,0,0,0.25);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    color: var(--heading-light);
    display: flex;
    align-items: center;
    gap: 0.4rem;
    transition: color 0.3s ease;
    background: linear-gradient(135deg, #1e3a5f, #3b6ea5);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
body.dark .logo {
    background: linear-gradient(135deg, #8ab4f8, #6a9bd1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    gap: 0.8rem;
    align-items: center;
    flex-wrap: wrap;
}

.nav-links a {
    color: var(--text-main-light);
    font-weight: 600;
    font-size: 0.92rem;
    padding: 0.4rem 0.6rem;
    border-radius: 8px;
    transition: background-color 0.2s ease, color 0.2s ease;
}
body.dark .nav-links a { color: var(--text-main-dark); }

.nav-links a:hover {
    background-color: rgba(30,58,95,0.06);
    text-decoration: none;
}
body.dark .nav-links a:hover { background-color: rgba(255,255,255,0.08); }

.btn-theme {
    background: var(--btn-bg-light);
    color: var(--btn-text-light);
    border: none;
    padding: 0.45rem 1.2rem;
    border-radius: 30px;
    cursor: pointer;
    font-weight: 700;
    font-size: 0.85rem;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.3s ease;
    box-shadow: 0 2px 8px rgba(30,58,95,0.25);
    white-space: nowrap;
}
body.dark .btn-theme {
    background: var(--btn-bg-dark);
    color: var(--btn-text-dark);
    box-shadow: 0 2px 8px rgba(59,110,165,0.3);
}
.btn-theme:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(30,58,95,0.3);
}
body.dark .btn-theme:hover { box-shadow: 0 4px 16px rgba(59,110,165,0.4); }

.menu-toggle {
    display: none;
    background: none;
    border: 1px solid var(--border-light);
    padding: 0.3rem 0.8rem;
    border-radius: 10px;
    font-size: 1.4rem;
    color: var(--text-main-light);
    cursor: pointer;
    line-height: 1;
    transition: border-color 0.2s ease;
}
body.dark .menu-toggle { color: var(--text-main-dark); border-color: var(--border-dark); }

@media (max-width: 900px) {
    .nav-links {
        flex-direction: column;
        align-items: stretch;
        width: 100%;
        display: none;
        padding: 0.8rem 0 0.4rem;
        gap: 0.3rem;
    }
    .nav-links.open { display: flex; animation: fadeInDown 0.3s ease; }
    .nav-links a { padding: 0.6rem 0.8rem; border-radius: 10px; }
    .menu-toggle { display: block; }
    .btn-theme { margin-top: 0.4rem; width: 100%; text-align: center; }
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ===== Hero 首屏 ===== */
.hero {
    background: linear-gradient(145deg, #eef3f9 0%, #dde7f0 40%, #e8f0f7 100%);
    padding: 4rem 0 3.5rem;
    border-radius: 0 0 48px 48px;
    position: relative;
    overflow: hidden;
}
body.dark .hero {
    background: linear-gradient(145deg, #1a2634 0%, #1f2c3a 50%, #17222e 100%);
}

.hero::before {
    content: '';
    position: absolute;
    top: -60%;
    right: -20%;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(244,197,66,0.08) 0%, transparent 70%);
    pointer-events: none;
}

.hero .container {
    display: flex;
    flex-wrap: wrap;
    gap: 2.5rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-text {
    flex: 1 1 320px;
    animation: slideUp 0.7s ease;
}

.hero-text h1 {
    font-size: clamp(1.9rem, 4.5vw, 2.8rem);
    margin-bottom: 1.2rem;
    background: linear-gradient(135deg, #0f1e2e, #1e3a5f);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}
body.dark .hero-text h1 {
    background: linear-gradient(135deg, #F8FAFC, #8ab4f8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-text p {
    font-size: 1.1rem;
    color: var(--text-secondary-light);
    margin-bottom: 1rem;
    max-width: 600px;
    line-height: 1.8;
}
body.dark .hero-text p { color: var(--text-secondary-dark); }

.hero-text p strong {
    color: #1e3a5f;
    font-weight: 700;
}
body.dark .hero-text p strong { color: #8ab4f8; }

.hero-svg {
    flex: 1 1 240px;
    min-width: 200px;
    text-align: center;
    animation: float 6s ease-in-out infinite;
}

.hero-svg svg {
    width: 100%;
    max-width: 260px;
    height: auto;
    border-radius: 30px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}
body.dark .hero-svg svg { box-shadow: 0 20px 50px rgba(0,0,0,0.3); }

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-12px); }
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 600px) {
    .hero { padding: 2.5rem 0 2rem; border-radius: 0 0 30px 30px; }
    .hero-svg svg { max-width: 180px; }
}

/* ===== 通用卡片 ===== */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1.8rem;
    margin: 2.5rem 0;
}

.card {
    background-color: var(--card-bg-light);
    padding: 1.8rem;
    border-radius: 24px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-light);
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    position: relative;
    overflow: hidden;
}
body.dark .card {
    background-color: var(--card-bg-dark);
    border-color: var(--border-dark);
    box-shadow: var(--shadow-dark);
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #1e3a5f, #3b6ea5, #f4c542);
    opacity: 0;
    transition: opacity 0.3s ease;
}
body.dark .card::before {
    background: linear-gradient(90deg, #8ab4f8, #6a9bd1, #f4c542);
}

.card:hover {
    transform: translateY(-6px) scale(1.01);
    box-shadow: 0 16px 40px rgba(0,0,0,0.1);
}
body.dark .card:hover { box-shadow: 0 16px 40px rgba(0,0,0,0.4); }

.card:hover::before { opacity: 1; }

.card h3 { margin-top: 0; font-size: 1.2rem; }
.card p { margin-bottom: 0.5rem; font-size: 0.95rem; }

/* ===== 表格 ===== */
.table-wrap {
    overflow-x: auto;
    background: var(--card-bg-light);
    padding: 1rem;
    border-radius: 16px;
    border: 1px solid var(--border-light);
    margin: 1.5rem 0;
    box-shadow: var(--shadow-light);
}
body.dark .table-wrap {
    background: var(--card-bg-dark);
    border-color: var(--border-dark);
    box-shadow: var(--shadow-dark);
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
}

th, td {
    padding: 0.8rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-light);
    color: var(--text-main-light);
    transition: background-color 0.2s ease;
}
body.dark th, body.dark td {
    color: var(--text-main-dark);
    border-bottom-color: var(--border-dark);
}

th {
    background-color: #e4edf5;
    color: #0f1e2e;
    font-weight: 700;
    letter-spacing: 0.02em;
}
body.dark th {
    background-color: #2a3a4e;
    color: #f1f5f9;
}

tr:hover td { background-color: rgba(30,58,95,0.02); }
body.dark tr:hover td { background-color: rgba(255,255,255,0.02); }

/* ===== 文章卡片 ===== */
.article-item {
    background: var(--card-bg-light);
    padding: 1.6rem 1.8rem;
    border-radius: 20px;
    margin-bottom: 1.2rem;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-light);
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}
body.dark .article-item {
    background: var(--card-bg-dark);
    border-color: var(--border-dark);
    box-shadow: var(--shadow-dark);
}

.article-item:hover {
    transform: translateX(6px);
    border-color: #3b6ea5;
    box-shadow: 0 12px 32px rgba(0,0,0,0.08);
}
body.dark .article-item:hover { border-color: #8ab4f8; box-shadow: 0 12px 32px rgba(0,0,0,0.3); }

.article-item h4 {
    margin: 0 0 0.4rem;
    font-size: 1.2rem;
    line-height: 1.4;
    transition: color 0.2s ease;
}
.article-item h4:hover { color: #1e4a7a; }
body.dark .article-item h4:hover { color: #8ab4f8; }

.article-meta {
    font-size: 0.85rem;
    color: var(--text-secondary-light);
    margin-bottom: 0.6rem;
    display: flex;
    gap: 0.8rem;
    flex-wrap: wrap;
}
body.dark .article-meta { color: var(--text-secondary-dark); }

.btn-read {
    background: var(--btn-bg-light);
    color: white;
    padding: 0.4rem 1.4rem;
    border-radius: 30px;
    display: inline-block;
    font-size: 0.85rem;
    font-weight: 600;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.3s ease;
    box-shadow: 0 2px 8px rgba(30,58,95,0.2);
}
body.dark .btn-read {
    background: var(--btn-bg-dark);
    color: white;
    box-shadow: 0 2px 8px rgba(59,110,165,0.3);
}
.btn-read:hover {
    transform: translateY(-2px);
    text-decoration: none;
    box-shadow: 0 4px 16px rgba(30,58,95,0.3);
}
body.dark .btn-read:hover { box-shadow: 0 4px 16px rgba(59,110,165,0.4); }

/* ===== FAQ ===== */
.faq-item {
    background: var(--card-bg-light);
    border-radius: 16px;
    padding: 0.2rem 1.5rem;
    margin-bottom: 0.8rem;
    border: 1px solid var(--border-light);
    box-shadow: 0 2px 8px rgba(0,0,0,0.02);
    transition: transform 0.2s ease, border-color 0.3s ease, box-shadow 0.3s ease;
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}
body.dark .faq-item {
    background: var(--card-bg-dark);
    border-color: var(--border-dark);
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}
.faq-item:hover {
    transform: scale(1.005);
    border-color: #3b6ea5;
}

details summary {
    font-weight: 700;
    font-size: 1.05rem;
    cursor: pointer;
    color: var(--heading-light);
    padding: 0.9rem 0;
    transition: color 0.2s ease;
    list-style: none;
    display: flex;
    align-items: center;
    gap: 0.6rem;
}
body.dark details summary { color: var(--heading-dark); }

details summary::-webkit-details-marker { display: none; }

details summary::before {
    content: '▸';
    color: #1e3a5f;
    transition: transform 0.3s ease, color 0.3s ease;
    font-size: 1.1rem;
}
body.dark details summary::before { color: #8ab4f8; }

details[open] summary::before {
    transform: rotate(90deg);
    color: #f4c542;
}

details p {
    margin: 0 0 1rem;
    padding-top: 0.4rem;
    color: var(--text-main-light);
    border-top: 1px dashed var(--border-light);
}
body.dark details p {
    color: var(--text-main-dark);
    border-top-color: var(--border-dark);
}

/* ===== 页脚 ===== */
.footer {
    background-color: var(--footer-bg-light);
    color: var(--footer-text-light);
    padding: 2.5rem 0 1.5rem;
    margin-top: 4rem;
    border-radius: 40px 40px 0 0;
    transition: background-color 0.3s ease, color 0.3s ease;
}
body.dark .footer {
    background-color: var(--footer-bg-dark);
    color: var(--footer-text-dark);
}

.footer a { color: #b0c8e0; transition: color 0.2s ease; }
body.dark .footer a { color: #8ab4f8; }
.footer a:hover { color: #f4c542; text-decoration: none; }

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 2rem;
    padding: 0 1rem;
}

.footer-copyright {
    border-top: 1px solid rgba(255,255,255,0.08);
    margin-top: 2rem;
    padding-top: 1.5rem;
    font-size: 0.9rem;
    color: var(--footer-text-light);
    text-align: center;
    opacity: 0.8;
}
body.dark .footer-copyright { color: var(--footer-text-dark); border-top-color: rgba(255,255,255,0.05); }

/* ===== 返回顶部 ===== */
.to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: linear-gradient(135deg, #1e3a5f, #3b6ea5);
    color: white;
    width: 3.2rem;
    height: 3.2rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.6rem;
    cursor: pointer;
    opacity: 0;
    border: none;
    z-index: 100;
    box-shadow: 0 4px 20px rgba(30,58,95,0.3);
    transition: opacity 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
    pointer-events: none;
}
body.dark .to-top {
    background: linear-gradient(135deg, #3b6ea5, #8ab4f8);
    box-shadow: 0 4px 20px rgba(59,110,165,0.4);
}
.to-top.visible {
    opacity: 0.9;
    pointer-events: auto;
}
.to-top:hover {
    transform: translateY(-4px) scale(1.05);
    opacity: 1;
    box-shadow: 0 8px 30px rgba(30,58,95,0.4);
}
body.dark .to-top:hover { box-shadow: 0 8px 30px rgba(59,110,165,0.5); }

/* ===== 工具类 ===== */
.text-secondary { color: var(--text-secondary-light); }
body.dark .text-secondary { color: var(--text-secondary-dark); }

.svg-placeholder { max-width: 100%; height: auto; }

.newsletter-input {
    padding: 0.6rem 1.2rem;
    border-radius: 30px;
    border: 1px solid var(--border-light);
    background: var(--card-bg-light);
    color: var(--text-main-light);
    font-size: 0.9rem;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.newsletter-input:focus {
    outline: none;
    border-color: #3b6ea5;
    box-shadow: 0 0 0 3px rgba(59,110,165,0.15);
}
body.dark .newsletter-input {
    background: var(--card-bg-dark);
    color: var(--text-main-dark);
    border-color: var(--border-dark);
}

.search-box { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.search-input {
    padding: 0.6rem 1.2rem;
    border-radius: 30px;
    border: 1px solid var(--border-light);
    background: var(--card-bg-light);
    color: var(--text-main-light);
    font-size: 0.9rem;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
body.dark .search-input {
    background: var(--card-bg-dark);
    color: var(--text-main-dark);
    border-color: var(--border-dark);
}
.search-input:focus {
    outline: none;
    border-color: #3b6ea5;
    box-shadow: 0 0 0 3px rgba(59,110,165,0.15);
}

.section-title { margin-top: 2.5rem; position: relative; }

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--heading-light);
    line-height: 1.2;
}
body.dark .stat-number { color: var(--heading-dark); }

/* ===== 区块间距 ===== */
section {
    margin-bottom: 2rem;
    scroll-margin-top: 80px;
}

/* ===== 特色卡片：产品/服务 ===== */
.feature-box {
    flex: 1;
    min-width: 200px;
    background: var(--card-bg-light);
    padding: 1.5rem;
    border-radius: 20px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-light);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    position: relative;
    overflow: hidden;
}
body.dark .feature-box {
    background: var(--card-bg-dark);
    border-color: var(--border-dark);
    box-shadow: var(--shadow-dark);
}
.feature-box::after {
    content: '';
    position: absolute;
    bottom: -30px;
    right: -30px;
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: rgba(244,197,66,0.08);
    transition: transform 0.4s ease;
}
.feature-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 16px 40px rgba(0,0,0,0.1);
}
body.dark .feature-box:hover { box-shadow: 0 16px 40px rgba(0,0,0,0.4); }
.feature-box:hover::after { transform: scale(2); }

/* ===== 内嵌内容通用 ===== */
.info-box {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    background: var(--card-bg-light);
    padding: 1.5rem;
    border-radius: 20px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-light);
    transition: transform 0.3s ease;
}
body.dark .info-box {
    background: var(--card-bg-dark);
    border-color: var(--border-dark);
    box-shadow: var(--shadow-dark);
}
.info-box:hover { transform: scale(1.005); }

.info-item {
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
}
.info-item strong { font-size: 1.05rem; }

/* ===== 响应式微调 ===== */
@media (max-width: 600px) {
    h1 { font-size: 1.8rem; }
    h2 { font-size: 1.4rem; }
    .hero-text h1 { font-size: 1.9rem; }
    .card-grid { grid-template-columns: 1fr; gap: 1.2rem; }
    .article-item { padding: 1.2rem; }
    .faq-item { padding: 0.1rem 1rem; }
    .to-top { bottom: 1.2rem; right: 1.2rem; width: 2.8rem; height: 2.8rem; font-size: 1.3rem; }
    .footer { border-radius: 24px 24px 0 0; }
    .navbar { padding: 0.5rem 0; }
    .logo { font-size: 1.3rem; }
}

/* ===== 滚动条美化 ===== */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, #1e3a5f, #3b6ea5);
    border-radius: 10px;
    border: 2px solid transparent;
    background-clip: content-box;
}
body.dark ::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, #3b6ea5, #8ab4f8);
    border: 2px solid transparent;
    background-clip: content-box;
}
::-webkit-scrollbar-thumb:hover {
    background: #1e3a5f;
    border: 0;
}
body.dark ::-webkit-scrollbar-thumb:hover { background: #8ab4f8; }

/* ===== 选中状态 ===== */
::selection {
    background: rgba(59,110,165,0.25);
    color: inherit;
}
body.dark ::selection { background: rgba(138,180,248,0.3); }

/* ===== 焦点可见性 ===== */
:focus-visible {
    outline: 3px solid rgba(59,110,165,0.5);
    outline-offset: 2px;
    border-radius: 2px;
}
body.dark :focus-visible { outline-color: rgba(138,180,248,0.6); }

/* ===== 减少动态偏好 ===== */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* ===== 打印样式 ===== */
@media print {
    .navbar, .to-top, .btn-theme, .menu-toggle { display: none !important; }
    body { background: white; color: black; }
    .card, .article-item, .faq-item, .feature-box, .info-box { 
        box-shadow: none; 
        border: 1px solid #ccc; 
        backdrop-filter: none;
        -webkit-backdrop-filter: none;
    }
    .hero { background: white; border-radius: 0; padding: 1rem 0; }
}
```