/* 全局重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
}

body {
    background: #f5f7fa;
    color: #1e2a3a;
    line-height: 1.6;
    scroll-behavior: smooth;
}

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

a:hover {
    color: #0d3b5c;
}

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

/* 导航吸顶 */
header {
    background: #ffffff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 0 20px;
    transition: box-shadow 0.3s;
}

header.scrolled {
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1a3a5c;
    letter-spacing: 1px;
}

.logo span {
    color: #c44536;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 30px;
}

nav ul li a {
    font-size: 0.95rem;
    color: #2c3e50;
    padding: 5px 0;
    border-bottom: 2px solid transparent;
    transition: border 0.2s;
}

nav ul li a:hover {
    border-bottom-color: #c44536;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 5px;
}

.menu-toggle span {
    width: 28px;
    height: 3px;
    background: #1a3a5c;
    border-radius: 3px;
    transition: 0.3s;
}

/* 移动菜单 */
@media(max-width:768px){
    nav ul {
        display: none;
        flex-direction: column;
        background: #fff;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        padding: 20px;
        box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        gap: 15px;
    }
    nav ul.active {
        display: flex;
    }
    .menu-toggle {
        display: flex;
    }
}

/* Banner 渐变 + 毛玻璃效果 */
.banner {
    position: relative;
    overflow: hidden;
    height: 450px;
    background: linear-gradient(135deg, #1a3a5c 0%, #2a5a7c 50%, #3a7a9c 100%);
    margin-bottom: 40px;
    border-radius: 0 0 20px 20px;
    backdrop-filter: blur(2px);
}

.banner-slide {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.8s ease;
    padding: 0 20px;
    text-align: center;
}

.banner-slide.active {
    opacity: 1;
}

.banner-content {
    color: #fff;
    max-width: 700px;
    background: rgba(255,255,255,0.1);
    backdrop-filter: blur(8px);
    padding: 40px 50px;
    border-radius: 20px;
    border: 1px solid rgba(255,255,255,0.2);
    box-shadow: 0 8px 32px rgba(0,0,0,0.2);
}

.banner-content h1 {
    font-size: 2.8rem;
    margin-bottom: 15px;
    text-shadow: 0 2px 8px rgba(0,0,0,0.3);
}

.banner-content p {
    font-size: 1.2rem;
    margin-bottom: 25px;
    opacity: 0.9;
}

.banner-btn {
    background: #c44536;
    color: #fff;
    padding: 14px 36px;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    display: inline-block;
    transition: background 0.3s, transform 0.2s;
    border: none;
    cursor: pointer;
}

.banner-btn:hover {
    background: #a33327;
    transform: scale(1.05);
}

.banner-dots {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 12px;
}

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

.banner-dots span.active {
    background: #fff;
}

/* 通用区块 */
.section {
    padding: 60px 0;
}

.section-title {
    font-size: 2rem;
    color: #1a3a5c;
    margin-bottom: 40px;
    text-align: center;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: #c44536;
    margin: 12px auto 0;
    border-radius: 2px;
}

.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.grid-3 {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 30px;
}

.grid-4 {
    display: grid;
    grid-template-columns: repeat(4,1fr);
    gap: 30px;
}

@media(max-width:768px){
    .grid-2, .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }
    .banner {
        height: 320px;
    }
    .banner-content h1 {
        font-size: 2rem;
    }
}

/* 圆角卡片 + 毛玻璃效果 */
.card {
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.04);
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid rgba(255,255,255,0.3);
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.08);
}

.icon-svg {
    width: 48px;
    height: 48px;
    margin-bottom: 15px;
    fill: none;
    stroke: #1a5a8c;
    stroke-width: 1.5;
}

.text-center {
    text-align: center;
}

.mt-20 {
    margin-top: 20px;
}

.mb-20 {
    margin-bottom: 20px;
}

.badge {
    display: inline-block;
    background: #eef4f8;
    color: #1a3a5c;
    padding: 4px 14px;
    border-radius: 20px;
    font-size: 0.85rem;
    margin-right: 8px;
    margin-bottom: 8px;
}

/* FAQ */
.faq-item {
    border-bottom: 1px solid #e8edf2;
    padding: 18px 0;
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-weight: 600;
    font-size: 1.05rem;
    color: #1a3a5c;
}

.faq-question::after {
    content: '+';
    font-size: 1.5rem;
    color: #c44536;
    transition: transform 0.3s;
}

.faq-item.open .faq-question::after {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
    padding-top: 0;
}

.faq-item.open .faq-answer {
    max-height: 400px;
    padding-top: 15px;
}

.faq-answer p {
    color: #3d5166;
    line-height: 1.7;
}

/* 文章列表 */
.article-item {
    padding: 20px 0;
    border-bottom: 1px solid #e8edf2;
}

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

.article-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: #1a3a5c;
}

.article-meta {
    font-size: 0.85rem;
    color: #7a8a9e;
    margin: 6px 0 10px;
}

.article-summary {
    color: #3d5166;
    font-size: 0.95rem;
}

.read-more {
    color: #c44536;
    font-weight: 600;
    font-size: 0.9rem;
    display: inline-block;
    margin-top: 8px;
}

/* 数字动画 */
.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: #c44536;
}

/* 返回顶部 */
.back-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: #1a3a5c;
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
    z-index: 999;
    border: none;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

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

/* 暗黑模式 */
.dark-toggle {
    background: none;
    border: 2px solid #1a3a5c;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #1a3a5c;
    transition: 0.3s;
}

body.dark {
    background: #121820;
    color: #d0d8e0;
}

body.dark header {
    background: #1a232e;
}

body.dark .card {
    background: rgba(30,41,54,0.85);
    backdrop-filter: blur(10px);
    border-color: rgba(255,255,255,0.1);
    box-shadow: 0 4px 16px rgba(0,0,0,0.3);
}

body.dark .faq-item {
    border-color: #2a3648;
}

body.dark .article-item {
    border-color: #2a3648;
}

body.dark .badge {
    background: #2a3648;
    color: #c8d0d8;
}

body.dark .logo {
    color: #e0e8f0;
}

body.dark .section-title {
    color: #d0d8e0;
}

body.dark .faq-question {
    color: #d0d8e0;
}

body.dark .article-title {
    color: #d0d8e0;
}

body.dark .article-summary {
    color: #aab4c0;
}

body.dark .article-meta {
    color: #8898a8;
}

body.dark .banner {
    background: linear-gradient(135deg, #0f1a28 0%, #1a2a3c 50%, #2a3a4c 100%);
}

body.dark .dark-toggle {
    border-color: #d0d8e0;
    color: #d0d8e0;
}

body.dark nav ul li a {
    color: #c8d0d8;
}

body.dark .back-top {
    background: #2a3648;
}

/* 搜索 */
.search-box {
    display: flex;
    gap: 0;
    max-width: 400px;
    margin: 0 auto 40px;
}

.search-box input {
    flex: 1;
    padding: 12px 18px;
    border: 2px solid #dce3ec;
    border-radius: 50px 0 0 50px;
    font-size: 1rem;
    outline: none;
    background: #fff;
    transition: border 0.3s;
}

.search-box input:focus {
    border-color: #1a5a8c;
}

.search-box button {
    background: #1a5a8c;
    color: #fff;
    border: none;
    padding: 12px 24px;
    border-radius: 0 50px 50px 0;
    cursor: pointer;
    font-weight: 600;
    transition: background 0.3s;
}

.search-box button:hover {
    background: #0d3b5c;
}

body.dark .search-box input {
    background: #1e2936;
    border-color: #2a3648;
    color: #d0d8e0;
}

/* 滚动动画 */
.fade-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* 页脚 */
footer {
    background: #1a2a3c;
    color: #b0c0d0;
    padding: 50px 0 30px;
    margin-top: 60px;
}

footer a {
    color: #8ab4d0;
}

footer a:hover {
    color: #b8d8e8;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
}

@media(max-width:768px){
    .footer-grid {
        grid-template-columns: 1fr;
    }
}

.footer-title {
    color: #e0e8f0;
    font-weight: 700;
    margin-bottom: 18px;
    font-size: 1.1rem;
}

footer ul {
    list-style: none;
}

footer ul li {
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid #2a3a4c;
    margin-top: 30px;
    font-size: 0.85rem;
}

/* 面包屑 */
.breadcrumb {
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(8px);
    padding: 12px 20px;
    border-radius: 8px;
    margin-bottom: 30px;
    font-size: 0.9rem;
    color: #5a6a7e;
    box-shadow: 0 1px 4px rgba(0,0,0,0.04);
    border: 1px solid rgba(255,255,255,0.3);
}

.breadcrumb a {
    color: #1a5a8c;
}

body.dark .breadcrumb {
    background: rgba(30,41,54,0.85);
    color: #aab4c0;
    border-color: rgba(255,255,255,0.1);
}

/* 联系我们信息块 */
.contact-info p {
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.contact-info svg {
    flex-shrink: 0;
}

/* 图片懒加载占位 */
.lazy-placeholder {
    background: #e8edf2;
    border-radius: 12px;
    min-height: 100px;
}

body.dark .lazy-placeholder {
    background: #2a3648;
}

/* 文章阅读全文弹窗模拟 */
.article-modal {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.6);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.article-modal.open {
    display: flex;
}

.modal-content {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(12px);
    max-width: 700px;
    width: 100%;
    border-radius: 20px;
    padding: 40px;
    max-height: 80vh;
    overflow-y: auto;
    position: relative;
    border: 1px solid rgba(255,255,255,0.3);
    box-shadow: 0 8px 32px rgba(0,0,0,0.2);
}

.modal-close {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 2rem;
    cursor: pointer;
    color: #5a6a7e;
    background: none;
    border: none;
}

body.dark .modal-content {
    background: rgba(30,41,54,0.95);
    color: #d0d8e0;
    border-color: rgba(255,255,255,0.1);
}

.modal-content h3 {
    color: #1a3a5c;
    margin-bottom: 15px;
}

body.dark .modal-content h3 {
    color: #d0d8e0;
}