/* ==================== 全局样式 ==================== */
:root {
    --primary-color: #0052D9;
    --secondary-color: #00A870;
    --dark-blue: #001F3F;
    --light-blue: #E8F3FF;
    --text-dark: #1A1A1A;
    --text-gray: #666666;
    --text-light: #999999;
    --bg-gray: #F5F7FA;
    --white: #FFFFFF;
    --border-color: #E5E5E5;
    --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.12);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 
                 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--white);
}

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

/* ==================== 导航栏 ==================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: var(--shadow);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    box-shadow: var(--shadow-hover);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 18px;
    font-weight: 600;
    color: var(--primary-color);
}

.logo img {
    height: 45px;
    width: auto;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 35px;
}

.nav-menu a {
    color: var(--text-dark);
    font-weight: 500;
    padding: 8px 0;
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 100%;
}

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

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    transition: all 0.3s ease;
}

/* ==================== 轮播Banner ==================== */
.hero-slider {
    position: relative;
    height: 600px;
    margin-top: 75px;
    overflow: hidden;
}

.slider-container {
    position: relative;
    height: 100%;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    opacity: 0;
    transition: opacity 1s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.slide::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(0, 31, 63, 0.7), rgba(0, 82, 217, 0.5));
}

.slide.active {
    opacity: 1;
}

.slide-content {
    position: relative;
    text-align: center;
    color: var(--white);
    max-width: 800px;
    padding: 0 20px;
    animation: slideUp 1s ease;
}

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

.slide-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.slide-subtitle {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.95;
}

.slider-controls {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    transform: translateY(-50%);
    display: flex;
    justify-content: space-between;
    padding: 0 20px;
    pointer-events: none;
}

.slider-btn {
    pointer-events: all;
    background: rgba(255, 255, 255, 0.3);
    border: none;
    color: var(--white);
    font-size: 40px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(5px);
}

.slider-btn:hover {
    background: rgba(255, 255, 255, 0.5);
    transform: scale(1.1);
}

.slider-dots {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: all 0.3s ease;
}

.dot.active {
    background: var(--white);
    width: 30px;
    border-radius: 6px;
}

/* ==================== 按钮样式 ==================== */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 6px;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.btn-primary {
    background: var(--primary-color);
    color: var(--white);
}

.btn-primary:hover {
    background: #003DA5;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 82, 217, 0.3);
}

.btn-outline {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background: transparent;
}

.btn-outline:hover {
    background: var(--primary-color);
    color: var(--white);
}

.btn-lg {
    padding: 15px 40px;
    font-size: 18px;
}

/* ==================== 章节标题 ==================== */
.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--dark-blue);
    margin-bottom: 15px;
}

.title-underline {
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    margin: 0 auto 20px;
    border-radius: 2px;
}

.section-subtitle {
    font-size: 18px;
    color: var(--text-gray);
}

/* ==================== 关于协会 ==================== */
.about-section {
    padding: 80px 0;
    background: var(--white);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text .lead {
    font-size: 18px;
    line-height: 1.8;
    margin-bottom: 20px;
    color: var(--text-dark);
}

.about-text p {
    margin-bottom: 20px;
    color: var(--text-gray);
    line-height: 1.8;
}

.about-text strong {
    color: var(--primary-color);
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin: 40px 0;
}

.stat-item {
    text-align: center;
    padding: 20px;
    background: var(--light-blue);
    border-radius: 8px;
}

.stat-number {
    font-size: 36px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-gray);
}

.about-image {
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-hover);
}

.about-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.about-image:hover img {
    transform: scale(1.05);
}

/* ==================== 核心业务 ==================== */
.services-section {
    padding: 80px 0;
    background: var(--bg-gray);
}

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

.service-card {
    background: var(--white);
    padding: 40px 25px;
    border-radius: 12px;
    text-align: center;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.service-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 25px;
    background: var(--light-blue);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.service-card:hover .service-icon {
    background: var(--primary-color);
    transform: rotateY(360deg);
}

.service-icon img {
    width: 40px;
    height: 40px;
    filter: brightness(0) saturate(100%) invert(27%) sepia(98%) saturate(2618%) hue-rotate(207deg);
}

.service-card:hover .service-icon img {
    filter: brightness(0) invert(1);
}

.service-card h3 {
    font-size: 20px;
    margin-bottom: 15px;
    color: var(--dark-blue);
}

.service-card p {
    color: var(--text-gray);
    line-height: 1.6;
}

/* ==================== 新闻动态 ==================== */
.news-section {
    padding: 80px 0;
    background: var(--white);
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-bottom: 50px;
    align-items: stretch;
}

.news-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.news-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.news-image {
    position: relative;
    overflow: hidden;
    aspect-ratio: 16 / 9;
    min-height: 220px;
    background: var(--bg-gray);
}

.news-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.news-card:hover .news-image img {
    transform: scale(1.1);
}

.news-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: var(--primary-color);
    color: var(--white);
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.news-content {
    padding: 25px;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.news-meta {
    display: flex;
    gap: 15px;
    margin-bottom: 12px;
    font-size: 14px;
    color: var(--text-light);
}

.news-category {
    color: var(--primary-color);
    font-weight: 500;
}

.news-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--dark-blue);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-excerpt {
    color: var(--text-gray);
    margin-bottom: 15px;
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-link {
    color: var(--primary-color);
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 5px;
    margin-top: auto;
}

.news-link:hover {
    gap: 10px;
}

/* ==================== 会员服务CTA ==================== */
.membership-cta {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--dark-blue), var(--primary-color));
    color: var(--white);
    text-align: center;
}

.cta-content h2 {
    font-size: 36px;
    margin-bottom: 15px;
}

.cta-content > p {
    font-size: 18px;
    margin-bottom: 40px;
    opacity: 0.9;
}

.cta-benefits {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 30px;
    margin-bottom: 40px;
}

.benefit-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 16px;
}

.benefit-icon {
    width: 24px;
    height: 24px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

/* ==================== 页脚 ==================== */
.footer {
    background: var(--dark-blue);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col h4 {
    font-size: 18px;
    margin-bottom: 20px;
    color: var(--white);
}

.footer-slogan {
    color: var(--secondary-color);
    font-weight: 500;
    margin: 10px 0;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: var(--white);
    padding-left: 5px;
}

.footer-contact li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    margin-bottom: 12px;
    color: rgba(255, 255, 255, 0.7);
}

.contact-icon {
    flex-shrink: 0;
}

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.social-link {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.social-link:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.social-link img {
    width: 20px;
    height: 20px;
    filter: brightness(0) invert(1);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
    text-align: center;
}

.footer-info p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 14px;
    margin-bottom: 8px;
}

/* ==================== 返回顶部 ==================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-hover);
    z-index: 999;
}

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

.back-to-top:hover {
    background: var(--dark-blue);
    transform: translateY(-5px);
}

/* ==================== 工具类 ==================== */
.text-center {
    text-align: center;
}

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

.mb-20 {
    margin-bottom: 20px;
}
/* ==================== 图片占位样式 ==================== */
.placeholder-image {
    background: linear-gradient(135deg, var(--light-blue) 0%, var(--primary-color) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 48px;
}

/* 图片加载占位动画 */
@keyframes imageLoading {
    0% { opacity: 0.8; }
    50% { opacity: 0.4; }
    100% { opacity: 0.8; }
}

.loading-placeholder {
    animation: imageLoading 1.5s ease-in-out infinite;
    background: linear-gradient(90deg, var(--light-blue) 25%, var(--bg-gray) 50%, var(--light-blue) 75%);
    background-size: 200% 100%;
}