```css
/* ===== 基础重置 & 可读性优先 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html { scroll-behavior: smooth; }
body {
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background-color: #f8fafc;
    color: #1f2937;
    line-height: 1.75;
    font-size: 16px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* 深色模式变量 */
body.dark-mode {
    background-color: #111827;
    color: #e2e8f0;
}

/* 所有文字层级颜色定义 — 高可读性 */
h1, h2, h3, h4, h5 {
    color: #0f172a;
    font-weight: 700;
    line-height: 1.3;
    transition: color 0.3s ease;
}
body.dark-mode h1,
body.dark-mode h2,
body.dark-mode h3,
body.dark-mode h4 {
    color: #f8fafc;
}
p, li, td, th, figcaption, blockquote {
    color: #1f2937;
}
body.dark-mode p,
body.dark-mode li,
body.dark-mode td,
body.dark-mode th,
body.dark-mode figcaption,
body.dark-mode blockquote {
    color: #e2e8f0;
}
a {
    color: #1d4ed8;
    text-decoration: none;
    font-weight: 500;
}
body.dark-mode a {
    color: #93c5fd;
}
a:hover {
    text-decoration: underline;
    color: #1e40af;
}
body.dark-mode a:hover {
    color: #dbeafe;
}

/* 辅助文字类 */
.muted, .meta, .date, .author, .summary {
    color: #334155;
}
body.dark-mode .muted,
body.dark-mode .meta,
body.dark-mode .date,
body.dark-mode .author,
body.dark-mode .summary {
    color: #cbd5e1;
}

/* 卡片背景与文字 */
.card {
    background: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 1.25rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
    transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease, border-color 0.3s ease;
}
.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.08);
}
body.dark-mode .card {
    background: #1e293b;
    border-color: #334155;
}
body.dark-mode .card:hover {
    box-shadow: 0 8px 16px rgba(0,0,0,0.4);
}

/* 按钮 */
.btn {
    background-color: #2563eb;
    color: #ffffff !important;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-weight: 600;
    display: inline-block;
    border: none;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
}
body.dark-mode .btn {
    background-color: #3b82f6;
    color: #f8fafc !important;
}
.btn:hover {
    background-color: #1d4ed8;
    transform: scale(1.02);
}
body.dark-mode .btn:hover {
    background-color: #2563eb;
}

/* 导航、footer */
.navbar, .site-footer {
    background-color: #0f172a;
    color: #e2e8f0;
}
body.dark-mode .navbar,
body.dark-mode .site-footer {
    background-color: #0b1220;
}
.navbar a, .site-footer a {
    color: #cbd5e1;
    transition: color 0.3s ease;
}
.navbar a:hover, .site-footer a:hover {
    color: #ffffff;
}

/* 表格 */
table {
    width: 100%;
    border-collapse: collapse;
}
th {
    background-color: #e2e8f0;
    color: #0f172a;
    font-weight: 600;
}
td, th {
    padding: 0.6rem 0.8rem;
    border: 1px solid #cbd5e1;
}
body.dark-mode th {
    background-color: #334155;
    color: #f1f5f9;
}

/* FAQ 答案 */
.faq-answer {
    border-left: 4px solid #2563eb;
    padding-left: 1rem;
    margin-top: 0.5rem;
}

/* 图片占位SVG保证对比 */
.placeholder-img {
    background-color: #e2e8f0;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 120px;
    color: #0f172a;
    font-weight: 600;
}
body.dark-mode .placeholder-img {
    background-color: #334155;
    color: #f1f5f9;
}

/* 吸顶导航 */
.sticky-nav {
    position: sticky;
    top: 0;
    z-index: 50;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    background: rgba(15, 23, 42, 0.85) !important;
    box-shadow: 0 2px 12px rgba(0,0,0,0.15);
    transition: background-color 0.3s ease;
}
body.dark-mode .sticky-nav {
    background: rgba(11, 18, 32, 0.85) !important;
}

/* 返回顶部按钮 */
#backTop {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background-color: #1d4ed8;
    color: white;
    padding: 0.75rem 1rem;
    border-radius: 50%;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    cursor: pointer;
    z-index: 100;
    border: none;
    font-size: 1.2rem;
    transition: background-color 0.3s ease, transform 0.3s ease, opacity 0.3s ease;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
}
#backTop.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
#backTop:hover {
    background-color: #1e40af;
    transform: scale(1.1);
}
body.dark-mode #backTop {
    background-color: #3b82f6;
}
body.dark-mode #backTop:hover {
    background-color: #2563eb;
}

/* Banner 轮播 */
.banner-slider {
    background: linear-gradient(135deg, #1e293b, #334155, #475569);
    color: #f8fafc;
    padding: 2.5rem 1rem;
    border-radius: 16px;
    position: relative;
    overflow: hidden;
    transition: background 0.3s ease;
}
.banner-slider::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(250, 204, 21, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 6s ease-in-out infinite;
}
.banner-slider::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 8s ease-in-out infinite reverse;
}
@keyframes float {
    0%, 100% { transform: translateY(0) scale(1); }
    50% { transform: translateY(-20px) scale(1.05); }
}
.banner-slider h2, .banner-slider p {
    color: #f8fafc !important;
    position: relative;
    z-index: 1;
}
.banner-slider .btn {
    position: relative;
    z-index: 1;
    background: #facc15;
    color: #0f172a !important;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.banner-slider .btn:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 20px rgba(250, 204, 21, 0.4);
}
body.dark-mode .banner-slider {
    background: linear-gradient(135deg, #0f172a, #1e293b, #334155);
}

/* 移动菜单 */
.mobile-menu {
    display: none;
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: 1rem;
    border-radius: 0 0 12px 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}
.mobile-menu a {
    display: block;
    padding: 0.5rem 0;
    color: #e2e8f0;
    transition: color 0.3s ease, padding-left 0.3s ease;
}
.mobile-menu a:hover {
    color: #facc15;
    padding-left: 0.5rem;
}
.mobile-menu.open { display: block; }

/* 滚动动画 */
.reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 面包屑样式 */
nav[aria-label="面包屑"] {
    padding: 0.5rem 0;
    font-size: 0.9rem;
}
nav[aria-label="面包屑"] span {
    transition: color 0.3s ease;
}

/* 分区标题样式 */
section > h2 {
    border-bottom: 3px solid #2563eb;
    padding-bottom: 0.5rem;
    margin-bottom: 1.5rem;
    position: relative;
    display: inline-block;
}
section > h2::after {
    content: '';
    position: absolute;
    bottom: -3px;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, #2563eb, #facc15);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}
section > h2:hover::after {
    transform: scaleX(1);
}

/* 卡片网格布局优化 */
section[style*="grid"] {
    transition: all 0.3s ease;
}

/* 文章卡片样式 */
#articles .card {
    position: relative;
    overflow: hidden;
}
#articles .card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(37, 99, 235, 0.1), transparent);
    transition: left 0.5s ease;
}
#articles .card:hover::before {
    left: 100%;
}

/* FAQ 样式优化 */
details {
    margin-bottom: 0.5rem;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    padding: 0.5rem 1rem;
    transition: border-color 0.3s ease, background-color 0.3s ease;
}
details:hover {
    border-color: #2563eb;
    background-color: rgba(37, 99, 235, 0.02);
}
details summary {
    cursor: pointer;
    font-weight: 600;
    color: #0f172a;
    transition: color 0.3s ease;
    position: relative;
    padding-right: 1.5rem;
}
details summary::after {
    content: '▾';
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    transition: transform 0.3s ease;
    color: #2563eb;
}
details[open] summary::after {
    transform: translateY(-50%) rotate(180deg);
}
body.dark-mode details {
    border-color: #334155;
}
body.dark-mode details summary {
    color: #f8fafc;
}
body.dark-mode details:hover {
    border-color: #3b82f6;
    background-color: rgba(59, 130, 246, 0.05);
}

/* HowTo 样式 */
#howto .card {
    border-left: 4px solid #2563eb;
}
#howto ol {
    padding-left: 1.5rem;
}
#howto ol li {
    margin-bottom: 0.25rem;
}

/* 联系卡片样式 */
#contact .card {
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
#contact .card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.08);
}

/* Footer 样式优化 */
.site-footer {
    background: linear-gradient(135deg, #0f172a, #1e293b);
    border-radius: 12px;
    margin-top: 2rem;
    padding: 1.5rem;
}
.site-footer h4 {
    color: #facc15;
    margin-bottom: 0.5rem;
}
.site-footer a {
    color: #cbd5e1;
    transition: color 0.3s ease;
}
.site-footer a:hover {
    color: #facc15;
    text-decoration: none;
}
body.dark-mode .site-footer {
    background: linear-gradient(135deg, #0b1220, #1e293b);
}

/* 响应式布局优化 */
@media (max-width: 768px) {
    body {
        font-size: 15px;
    }
    .banner-slider {
        padding: 1.5rem 1rem;
    }
    .banner-slider h2 {
        font-size: 1.3rem;
    }
    .card {
        padding: 1rem;
    }
    section[style*="grid"] {
        grid-template-columns: 1fr !important;
    }
    section[style*="flex"] {
        flex-direction: column;
    }
    #backTop {
        bottom: 1rem;
        right: 1rem;
        padding: 0.5rem 0.75rem;
        font-size: 1rem;
    }
    .site-footer {
        padding: 1rem;
    }
    .site-footer div {
        flex: 1 1 100%;
        margin-bottom: 1rem;
    }
    .mobile-menu-toggle {
        display: inline-block;
    }
    .desktop-menu {
        display: none;
    }
}

@media (min-width: 769px) {
    .mobile-menu-toggle {
        display: none;
    }
    .desktop-menu {
        display: flex;
    }
}

/* 滚动条美化 */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}
::-webkit-scrollbar-track {
    background: #f1f5f9;
    border-radius: 5px;
}
::-webkit-scrollbar-thumb {
    background: #94a3b8;
    border-radius: 5px;
    transition: background 0.3s ease;
}
::-webkit-scrollbar-thumb:hover {
    background: #64748b;
}
body.dark-mode ::-webkit-scrollbar-track {
    background: #1e293b;
}
body.dark-mode ::-webkit-scrollbar-thumb {
    background: #475569;
}
body.dark-mode ::-webkit-scrollbar-thumb:hover {
    background: #334155;
}

/* 选中文字样式 */
::selection {
    background-color: #facc15;
    color: #0f172a;
}
body.dark-mode ::selection {
    background-color: #3b82f6;
    color: #f8fafc;
}

/* 焦点样式提升可访问性 */
:focus-visible {
    outline: 3px solid #2563eb;
    outline-offset: 2px;
    border-radius: 4px;
}
body.dark-mode :focus-visible {
    outline-color: #3b82f6;
}

/* 减少动画偏好处理 */
@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;
    }
    .reveal {
        opacity: 1;
        transform: none;
    }
}
```