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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
    color: #222;
    background: #f8fafc;
    line-height: 1.7;
}

a {
    color: #1a5c9e;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航吸顶 */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(226, 232, 240, 0.6);
    padding: 12px 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
    transition: background 0.3s, box-shadow 0.3s;
}

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

.navbar .logo {
    font-size: 1.3rem;
    font-weight: 700;
    color: #0a2540;
    transition: color 0.3s;
}

.navbar .logo span {
    color: #1a5c9e;
}

.nav-links {
    display: flex;
    gap: 24px;
    list-style: none;
}

.nav-links a {
    color: #333;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.3s, transform 0.2s;
}

.nav-links a:hover {
    color: #1a5c9e;
    transform: translateY(-2px);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #0a2540;
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        width: 100%;
        margin-top: 12px;
        gap: 12px;
    }
    .nav-links.active {
        display: flex;
    }
    .menu-toggle {
        display: block;
    }
}

/* 面包屑 */
.breadcrumb {
    background: rgba(238, 242, 246, 0.8);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    padding: 10px 0;
    font-size: 0.9rem;
}

.breadcrumb a {
    color: #1a5c9e;
}

.breadcrumb span {
    color: #555;
}

/* 通用标题 */
h1 {
    font-size: 2rem;
    color: #0a2540;
    margin: 30px 0 20px;
    line-height: 1.3;
}

h2 {
    font-size: 1.6rem;
    color: #0a2540;
    margin: 40px 0 20px;
    border-left: 4px solid #1a5c9e;
    padding-left: 14px;
}

h3 {
    font-size: 1.2rem;
    color: #1a3a5c;
    margin: 28px 0 14px;
}

h4 {
    font-size: 1rem;
    color: #2c3e50;
    margin: 20px 0 10px;
    font-weight: 600;
}

p {
    margin-bottom: 16px;
}

/* banner轮播 */
.banner {
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, #0a2540 0%, #1a5c9e 50%, #2d7dd2 100%);
    color: #fff;
    text-align: center;
    padding: 60px 20px;
    border-radius: 16px;
    margin: 20px 0;
    min-height: 280px;
    box-shadow: 0 8px 32px rgba(26, 92, 158, 0.25);
}

.banner-slide {
    display: none;
}

.banner-slide.active {
    display: block;
    animation: fadeIn 0.6s;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.banner h2 {
    font-size: 1.8rem;
    border: none;
    padding: 0;
    color: #fff;
    margin: 0 0 12px;
}

.banner p {
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto;
    opacity: 0.9;
}

.banner-dots {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 24px;
}

.banner-dots span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.4);
    cursor: pointer;
    transition: background 0.3s, transform 0.2s;
}

.banner-dots span.active {
    background: #fff;
    transform: scale(1.2);
}

/* 卡片网格 */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
    margin: 24px 0;
}

.card {
    background: rgba(255, 255, 255, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    transition: transform 0.3s, box-shadow 0.3s, background 0.3s;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.12);
    background: rgba(255, 255, 255, 0.9);
}

.card h3 {
    margin-top: 0;
}

.card svg {
    width: 48px;
    height: 48px;
    margin-bottom: 12px;
    transition: transform 0.3s;
}

.card:hover svg {
    transform: scale(1.1);
}

/* FAQ */
.faq-item {
    border-bottom: 1px solid #e2e8f0;
    padding: 14px 0;
    transition: background 0.3s;
}

.faq-item:hover {
    background: rgba(26, 92, 158, 0.03);
}

.faq-question {
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: #0a2540;
    transition: color 0.3s;
}

.faq-question::after {
    content: '+';
    font-size: 1.4rem;
    transition: transform 0.2s;
}

.faq-item.open .faq-question::after {
    content: '−';
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding-top 0.3s;
    padding-top: 0;
}

.faq-item.open .faq-answer {
    max-height: 600px;
    padding-top: 12px;
}

/* 文章列表 */
.article-item {
    border-bottom: 1px solid #eef2f6;
    padding: 18px 0;
    transition: padding-left 0.3s, background 0.3s;
}

.article-item:hover {
    padding-left: 8px;
    background: rgba(26, 92, 158, 0.02);
}

.article-item h3 {
    margin: 0 0 6px;
}

.article-meta {
    color: #666;
    font-size: 0.85rem;
    margin-bottom: 8px;
}

.article-summary {
    color: #444;
}

.read-more {
    color: #1a5c9e;
    font-weight: 500;
    transition: color 0.3s, padding-left 0.3s;
}

.read-more:hover {
    color: #0a2540;
    padding-left: 4px;
}

/* 返回顶部 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 44px;
    height: 44px;
    background: #1a5c9e;
    color: #fff;
    border: none;
    border-radius: 50%;
    font-size: 1.4rem;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    z-index: 999;
    transition: background 0.3s, transform 0.2s, box-shadow 0.3s;
}

.back-to-top.visible {
    display: flex;
}

.back-to-top:hover {
    background: #0a2540;
    transform: scale(1.1);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.3);
}

/* 暗黑模式 */
.dark-mode-toggle {
    position: fixed;
    bottom: 90px;
    right: 30px;
    background: rgba(51, 51, 51, 0.85);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    color: #fff;
    border: none;
    border-radius: 24px;
    padding: 8px 16px;
    cursor: pointer;
    font-size: 0.85rem;
    z-index: 999;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    transition: background 0.3s, transform 0.2s;
}

.dark-mode-toggle:hover {
    background: #1a5c9e;
    transform: scale(1.05);
}

body.dark {
    background: #0f172a;
    color: #e2e8f0;
}

body.dark .navbar {
    background: rgba(30, 41, 59, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-color: #334155;
}

body.dark .navbar .logo {
    color: #e2e8f0;
}

body.dark .nav-links a {
    color: #cbd5e1;
}

body.dark .card {
    background: rgba(30, 41, 59, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    color: #e2e8f0;
    border-color: rgba(51, 65, 85, 0.5);
}

body.dark .card:hover {
    background: rgba(30, 41, 59, 0.9);
}

body.dark .breadcrumb {
    background: rgba(30, 41, 59, 0.8);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

body.dark .faq-item {
    border-color: #334155;
}

body.dark .faq-item:hover {
    background: rgba(59, 130, 246, 0.05);
}

body.dark .article-item {
    border-color: #334155;
}

body.dark .back-to-top {
    background: #3b82f6;
}

body.dark .back-to-top:hover {
    background: #2563eb;
}

body.dark h1,
body.dark h2,
body.dark h3,
body.dark h4 {
    color: #e2e8f0;
}

body.dark .article-meta,
body.dark .article-summary {
    color: #94a3b8;
}

body.dark .faq-question {
    color: #e2e8f0;
}

/* 数字动画 */
.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: #1a5c9e;
    transition: color 0.3s;
}

body.dark .stat-number {
    color: #3b82f6;
}

/* 搜索 */
.search-box {
    display: flex;
    gap: 8px;
    margin: 20px 0;
}

.search-box input {
    flex: 1;
    padding: 10px 16px;
    border: 1px solid #ccc;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s, box-shadow 0.3s;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

.search-box input:focus {
    border-color: #1a5c9e;
    box-shadow: 0 0 0 3px rgba(26, 92, 158, 0.15);
    outline: none;
}

.search-box button {
    padding: 10px 20px;
    background: #1a5c9e;
    color: #fff;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: background 0.3s, transform 0.2s;
}

.search-box button:hover {
    background: #0a2540;
    transform: scale(1.02);
}

body.dark .search-box input {
    background: rgba(30, 41, 59, 0.8);
    border-color: #334155;
    color: #e2e8f0;
}

body.dark .search-box input:focus {
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

/* 页脚 */
footer {
    background: linear-gradient(135deg, #0a2540 0%, #1a3a5c 100%);
    color: #cbd5e1;
    padding: 40px 0 20px;
    margin-top: 50px;
}

footer a {
    color: #93c5fd;
    transition: color 0.3s;
}

footer a:hover {
    color: #fff;
}

footer .footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 24px;
}

footer h4 {
    color: #fff;
    margin-bottom: 12px;
}

footer ul {
    list-style: none;
}

footer ul li {
    margin-bottom: 6px;
}

.copyright {
    text-align: center;
    border-top: 1px solid #1e3a5f;
    padding-top: 20px;
    margin-top: 30px;
    font-size: 0.85rem;
}

/* 滚动动画 */
.fade-up {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s, transform 0.6s;
}

.fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 响应式微调 */
@media (max-width: 768px) {
    .banner {
        padding: 40px 16px;
        min-height: 220px;
    }
    .banner h2 {
        font-size: 1.4rem;
    }
    .banner p {
        font-size: 0.95rem;
    }
    h1 {
        font-size: 1.6rem;
    }
    h2 {
        font-size: 1.3rem;
    }
    .grid {
        grid-template-columns: 1fr;
    }
    .back-to-top {
        width: 36px;
        height: 36px;
        font-size: 1.2rem;
        bottom: 20px;
        right: 20px;
    }
    .dark-mode-toggle {
        bottom: 70px;
        right: 20px;
        font-size: 0.75rem;
        padding: 6px 12px;
    }
    footer .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 480px) {
    footer .footer-grid {
        grid-template-columns: 1fr;
    }
}