/* ===== 全局重置与基础 ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background: #f8fafc;
    color: #1e293b;
    line-height: 1.7;
    min-height: 100vh;
    transition: background 0.4s, color 0.4s;
}

a {
    color: #1a5a8c;
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    text-decoration: underline;
    color: #c44536;
}

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

ul, ol {
    list-style: none;
}

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

/* ===== 导航栏 ===== */
.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;
    transition: box-shadow 0.3s, background 0.3s;
}

.navbar.scrolled {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    background: rgba(255, 255, 255, 0.95);
}

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

.logo {
    font-size: 1.6rem;
    font-weight: 700;
    color: #0f2b45;
    letter-spacing: 1px;
    background: linear-gradient(135deg, #0f2b45 0%, #1a3a5c 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo span {
    background: linear-gradient(135deg, #c44536, #e05a4a);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-links li a {
    font-size: 0.95rem;
    padding: 6px 0;
    color: #334155;
    font-weight: 500;
    border-bottom: 2px solid transparent;
    transition: all 0.3s ease;
    position: relative;
}

.nav-links li a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #c44536, #e05a4a);
    transition: width 0.3s;
}

.nav-links li a:hover {
    color: #0f2b45;
    text-decoration: none;
}

.nav-links li a:hover::after {
    width: 100%;
}

.menu-toggle {
    display: none;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(4px);
    border: 1px solid #cbd5e1;
    padding: 8px 14px;
    border-radius: 10px;
    font-size: 1.3rem;
    cursor: pointer;
    color: #1e293b;
    transition: all 0.2s;
}

.menu-toggle:hover {
    background: #f1f5f9;
    border-color: #94a3b8;
}

/* ===== 返回顶部 ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #1a3a5c, #0f2b45);
    color: #fff;
    border: none;
    border-radius: 50%;
    font-size: 1.6rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 999;
    box-shadow: 0 6px 20px rgba(15, 43, 69, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top:hover {
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 8px 28px rgba(15, 43, 69, 0.4);
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

/* ===== 轮播Banner ===== */
.banner {
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, #0f2b45 0%, #1a3a5c 50%, #1a5a8c 100%);
    color: #fff;
    padding: 80px 0;
    min-height: 380px;
    display: flex;
    align-items: center;
}

.banner::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 50%, rgba(196, 69, 54, 0.15) 0%, transparent 50%),
                radial-gradient(circle at 70% 50%, rgba(26, 90, 140, 0.2) 0%, transparent 50%);
    animation: bannerGlow 10s ease-in-out infinite alternate;
}

@keyframes bannerGlow {
    0% { transform: translate(0, 0); }
    100% { transform: translate(-10%, -5%); }
}

.banner-slide {
    display: none;
    animation: fadeSlide 0.8s ease;
    position: relative;
    z-index: 1;
}

.banner-slide.active {
    display: block;
}

@keyframes fadeSlide {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.banner-content {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.banner-content h1 {
    font-size: 2.8rem;
    margin-bottom: 20px;
    line-height: 1.2;
    font-weight: 800;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.banner-content p {
    font-size: 1.2rem;
    opacity: 0.92;
    margin-bottom: 28px;
    text-shadow: 0 1px 4px rgba(0, 0, 0, 0.15);
}

.banner-btn {
    display: inline-block;
    background: linear-gradient(135deg, #c44536, #e05a4a);
    color: #fff;
    padding: 14px 40px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 15px rgba(196, 69, 54, 0.3);
    position: relative;
    overflow: hidden;
}

.banner-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.6s;
}

.banner-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(196, 69, 54, 0.4);
    text-decoration: none;
    color: #fff;
}

.banner-btn:hover::before {
    left: 100%;
}

.banner-dots {
    display: flex;
    justify-content: center;
    gap: 14px;
    margin-top: 40px;
    position: relative;
    z-index: 1;
}

.banner-dots span {
    width: 14px;
    height: 14px;
    background: rgba(255, 255, 255, 0.25);
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s;
    backdrop-filter: blur(2px);
    border: 2px solid transparent;
}

.banner-dots span:hover {
    background: rgba(255, 255, 255, 0.5);
    transform: scale(1.1);
}

.banner-dots span.active {
    background: #fff;
    transform: scale(1.2);
    border-color: rgba(196, 69, 54, 0.3);
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.3);
}

/* ===== 通用区块 ===== */
.section {
    padding: 80px 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: #0f2b45;
    margin-bottom: 16px;
    text-align: center;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, #c44536, #e05a4a);
    margin: 12px auto 0;
    border-radius: 4px;
}

.section-sub {
    text-align: center;
    color: #64748b;
    margin-bottom: 48px;
    font-size: 1.05rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.grid-2, .grid-3, .grid-4 {
    display: grid;
    gap: 30px;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ===== 卡片 ===== */
.card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 20px;
    padding: 32px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid rgba(238, 242, 246, 0.6);
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
    border-color: rgba(196, 69, 54, 0.15);
    background: rgba(255, 255, 255, 0.95);
}

.card h3 {
    font-size: 1.3rem;
    margin-bottom: 12px;
    color: #0f2b45;
    font-weight: 600;
}

.card p {
    color: #475569;
    font-size: 0.95rem;
    line-height: 1.7;
}

.card ul, .card ol {
    color: #475569;
    font-size: 0.95rem;
    line-height: 1.8;
}

.icon-svg {
    width: 52px;
    height: 52px;
    margin-bottom: 18px;
    fill: #c44536;
    transition: transform 0.3s;
}

.card:hover .icon-svg {
    transform: scale(1.1) rotate(-5deg);
}

/* ===== 统计数字 ===== */
.stats-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 50px;
    padding: 20px 0;
}

.stat-item {
    text-align: center;
    min-width: 140px;
    padding: 20px 30px;
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(8px);
    border-radius: 20px;
    border: 1px solid rgba(226, 232, 240, 0.4);
    transition: transform 0.3s;
}

.stat-item:hover {
    transform: translateY(-4px);
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    background: linear-gradient(135deg, #c44536, #e05a4a);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.stat-label {
    color: #64748b;
    font-size: 1rem;
    margin-top: 8px;
    font-weight: 500;
}

/* ===== FAQ ===== */
.faq-item {
    border-bottom: 1px solid rgba(226, 232, 240, 0.6);
    padding: 20px 0;
    transition: all 0.3s;
}

.faq-item:first-child {
    border-top: 1px solid rgba(226, 232, 240, 0.6);
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-weight: 600;
    font-size: 1.05rem;
    color: #0f2b45;
    padding: 4px 0;
    transition: color 0.2s;
}

.faq-question:hover {
    color: #c44536;
}

.faq-question::after {
    content: '+';
    font-size: 1.6rem;
    color: #c44536;
    transition: all 0.3s;
    flex-shrink: 0;
    margin-left: 16px;
    font-weight: 300;
}

.faq-item.open .faq-question::after {
    content: '−';
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.3s;
    padding-top: 0;
    color: #475569;
    line-height: 1.7;
}

.faq-item.open .faq-answer {
    max-height: 600px;
    padding-top: 18px;
}

/* ===== 文章卡片 ===== */
.article-card {
    border-bottom: 1px solid rgba(226, 232, 240, 0.6);
    padding: 24px 0;
    transition: all 0.3s;
    padding-left: 8px;
    padding-right: 8px;
    border-radius: 8px;
}

.article-card:last-child {
    border-bottom: none;
}

.article-card:hover {
    background: rgba(255, 255, 255, 0.5);
    padding-left: 16px;
    padding-right: 16px;
}

.article-card h4 {
    font-size: 1.15rem;
    margin-bottom: 6px;
}

.article-card h4 a {
    color: #0f2b45;
    transition: color 0.2s;
}

.article-card h4 a:hover {
    color: #c44536;
    text-decoration: none;
}

.article-card .meta {
    color: #94a3b8;
    font-size: 0.85rem;
    margin-bottom: 8px;
}

.article-card p {
    color: #475569;
    font-size: 0.95rem;
}

.read-more {
    color: #c44536;
    font-weight: 500;
    display: inline-block;
    margin-top: 10px;
    transition: all 0.2s;
}

.read-more:hover {
    transform: translateX(4px);
    text-decoration: none;
}

/* ===== 搜索框 ===== */
.search-box {
    display: flex;
    gap: 10px;
    max-width: 480px;
    margin: 0 auto 40px;
}

.search-box input {
    flex: 1;
    padding: 12px 20px;
    border: 2px solid #e2e8f0;
    border-radius: 30px;
    font-size: 1rem;
    outline: none;
    transition: all 0.3s;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(4px);
}

.search-box input:focus {
    border-color: #c44536;
    box-shadow: 0 0 0 3px rgba(196, 69, 54, 0.1);
}

.search-box button {
    background: linear-gradient(135deg, #c44536, #e05a4a);
    color: #fff;
    border: none;
    padding: 12px 24px;
    border-radius: 30px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s;
    box-shadow: 0 4px 12px rgba(196, 69, 54, 0.2);
}

.search-box button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(196, 69, 54, 0.3);
}

/* ===== 面包屑 ===== */
.breadcrumb {
    padding: 20px 0;
    font-size: 0.9rem;
    color: #64748b;
}

.breadcrumb a {
    color: #1a5a8c;
    transition: color 0.2s;
}

.breadcrumb a:hover {
    color: #c44536;
}

.breadcrumb span {
    margin: 0 8px;
    color: #94a3b8;
}

/* ===== 页脚 ===== */
.footer {
    background: linear-gradient(135deg, #0b1a2e 0%, #0f2b45 100%);
    color: #cbd5e1;
    padding: 60px 0 30px;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #c44536, #e05a4a, #1a5a8c);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 40px;
}

.footer h4 {
    color: #fff;
    margin-bottom: 18px;
    font-size: 1.1rem;
    font-weight: 600;
    position: relative;
    padding-bottom: 8px;
}

.footer h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background: #c44536;
}

.footer ul {
    list-style: none;
}

.footer ul li {
    margin-bottom: 10px;
}

.footer ul li a {
    color: #94a3b8;
    font-size: 0.9rem;
    transition: all 0.2s;
}

.footer ul li a:hover {
    color: #fff;
    text-decoration: none;
    padding-left: 4px;
}

.footer-bottom {
    border-top: 1px solid rgba(30, 58, 95, 0.6);
    padding-top: 24px;
    margin-top: 40px;
    text-align: center;
    font-size: 0.85rem;
    color: #64748b;
}

/* ===== 暗黑模式切换按钮 ===== */
.dark-mode-toggle {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(4px);
    border: 1px solid #cbd5e1;
    padding: 6px 18px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    color: #1e293b;
    transition: all 0.3s;
}

.dark-mode-toggle:hover {
    background: #f1f5f9;
    border-color: #94a3b8;
}

/* ===== 暗黑模式 ===== */
body.dark {
    background: #0f172a;
    color: #e2e8f0;
}

body.dark .navbar {
    background: rgba(30, 41, 59, 0.85);
    backdrop-filter: blur(12px);
    border-color: rgba(51, 65, 85, 0.6);
}

body.dark .navbar.scrolled {
    background: rgba(30, 41, 59, 0.95);
}

body.dark .card {
    background: rgba(30, 41, 59, 0.8);
    backdrop-filter: blur(12px);
    border-color: rgba(51, 65, 85, 0.4);
}

body.dark .card:hover {
    background: rgba(30, 41, 59, 0.95);
    border-color: rgba(196, 69, 54, 0.2);
}

body.dark .footer {
    background: linear-gradient(135deg, #0b1a2e, #0f172a);
}

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

body.dark .section-title {
    color: #f1f5f9;
}

body.dark .section-sub {
    color: #94a3b8;
}

body.dark .dark-mode-toggle {
    color: #e2e8f0;
    border-color: #475569;
    background: rgba(51, 65, 85, 0.6);
}

body.dark .dark-mode-toggle:hover {
    background: rgba(71, 85, 105, 0.8);
}

body.dark .breadcrumb {
    color: #94a3b8;
}

body.dark .breadcrumb a {
    color: #60a5fa;
}

body.dark .stat-item {
    background: rgba(30, 41, 59, 0.6);
    border-color: rgba(51, 65, 85, 0.4);
}

body.dark .article-card:hover {
    background: rgba(30, 41, 59, 0.4);
}

body.dark .article-card h4 a {
    color: #e2e8f0;
}

body.dark .search-box input {
    background: rgba(30, 41, 59, 0.8);
    border-color: #475569;
    color: #e2e8f0;
}

body.dark .search-box input:focus {
    border-color: #c44536;
}

body.dark .menu-toggle {
    background: rgba(30, 41, 59, 0.8);
    border-color: #475569;
    color: #e2e8f0;
}

body.dark .menu-toggle:hover {
    background: rgba(51, 65, 85, 0.8);
}

body.dark .banner {
    background: linear-gradient(135deg, #0b1a2e 0%, #0f2b45 50%, #1a3a5c 100%);
}

body.dark .logo {
    background: linear-gradient(135deg, #e2e8f0, #f1f5f9);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

body.dark .nav-links li a {
    color: #94a3b8;
}

body.dark .nav-links li a:hover {
    color: #f1f5f9;
}

/* ===== 滚动动画 ===== */
.fade-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        width: 100%;
        flex-direction: column;
        gap: 12px;
        padding: 20px 0 10px;
        background: rgba(255, 255, 255, 0.95);
        backdrop-filter: blur(12px);
        border-radius: 16px;
        margin-top: 12px;
    }

    body.dark .nav-links {
        background: rgba(30, 41, 59, 0.95);
    }

    .nav-links.open {
        display: flex;
    }

    .menu-toggle {
        display: block;
    }

    .grid-2, .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }

    .banner-content h1 {
        font-size: 2rem;
    }

    .banner-content p {
        font-size: 1rem;
    }

    .banner {
        padding: 50px 0;
        min-height: 300px;
    }

    .section {
        padding: 50px 0;
    }

    .section-title {
        font-size: 1.6rem;
    }

    .stats-grid {
        gap: 24px;
    }

    .stat-item {
        min-width: 120px;
        padding: 16px 20px;
    }

    .stat-number {
        font-size: 2.2rem;
    }

    .card {
        padding: 24px;
    }

    .footer-grid {
        gap: 30px;
    }

    .back-to-top {
        width: 44px;
        height: 44px;
        font-size: 1.4rem;
        bottom: 20px;
        right: 20px;
    }

    .search-box {
        flex-direction: column;
    }

    .search-box input {
        width: 100%;
    }

    .search-box button {
        width: 100%;
    }

    .footer ul {
        columns: 2;
    }
}

@media (max-width: 480px) {
    .banner-content h1 {
        font-size: 1.6rem;
    }

    .banner-btn {
        padding: 12px 28px;
        font-size: 0.9rem;
    }

    .section-title {
        font-size: 1.4rem;
    }

    .card {
        padding: 20px;
    }

    .stat-item {
        min-width: 100px;
        padding: 12px 16px;
    }

    .stat-number {
        font-size: 1.8rem;
    }
}