/* CSS Variables */
:root {
    --primary-color: #0066cc;
    --secondary-color: #00a0a0;
    --accent-color: #ff6b35;
    --dark-color: #1a1a2e;
    --light-gray: #f5f7fa;
    --gray: #666;
    --white: #ffffff;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --transition: all 0.3s ease;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.8;
    color: #333;
    background: #fafafa;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

/* Header */
.header {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
    border-bottom: 1px solid #eee;
}

.logo img {
    height: 80px;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.lang-switch {
    color: var(--primary-color);
    font-size: 14px;
    padding: 5px 15px;
    border: 1px solid var(--primary-color);
    border-radius: 20px;
}

.lang-switch:hover {
    background: var(--primary-color);
    color: var(--white);
}

.search-box {
    display: flex;
    border: 1px solid #ddd;
    border-radius: 25px;
    overflow: hidden;
}

.search-box input {
    border: none;
    padding: 8px 15px;
    width: 180px;
    outline: none;
}

.search-box button {
    border: none;
    background: var(--primary-color);
    color: var(--white);
    padding: 8px 15px;
    cursor: pointer;
}

/* Main Navigation */
.main-nav {
    background: var(--white);
}

.main-nav ul {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
}

.main-nav > ul > li {
    position: relative;
}

.main-nav > ul > li > a {
    display: block;
    padding: 18px 22px;
    color: #333;
    font-weight: 500;
    font-size: 15px;
}

.main-nav > ul > li > a:hover {
    color: var(--primary-color);
    background: var(--light-gray);
}

/* Dropdown */
.dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--white);
    min-width: 180px;
    box-shadow: var(--shadow);
    border-radius: 4px;
    overflow: hidden;
    z-index: 100;
}

.dropdown:hover .dropdown-content {
    display: block;
}

.dropdown-content a {
    display: block;
    padding: 12px 20px;
    color: #333;
    font-size: 14px;
}

.dropdown-content a:hover {
    background: var(--primary-color);
    color: var(--white);
}

.dropdown > a::after {
    content: ' \f107';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    font-size: 10px;
    margin-left: 5px;
}

/* Hero Slider */
.hero-slider {
    position: relative;
    height: 450px;
    overflow: hidden;
}

.slider-container {
    height: 100%;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.8s ease;
}

.slide.active {
    opacity: 1;
}

.slide-content {
    text-align: center;
    color: var(--white);
    z-index: 2;
}

.slide-content h1 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 15px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.slide-content p {
    font-size: 20px;
    opacity: 0.9;
}

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

.slider-nav span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255,255,255,0.5);
    cursor: pointer;
    transition: var(--transition);
}

.slider-nav span.active {
    background: var(--white);
    transform: scale(1.2);
}

/* Quick Links */
.quick-links {
    background: var(--white);
    padding: 30px 0;
    margin-bottom: 40px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.quick-links-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 20px;
}

.quick-link-card {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 20px;
    background: linear-gradient(135deg, var(--light-gray) 0%, #e8f4f8 100%);
    border-radius: 10px;
    text-align: center;
    justify-content: center;
}

.quick-link-card i {
    font-size: 32px;
    color: var(--primary-color);
}

.quick-link-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.quick-link-card span {
    font-weight: 500;
    color: #333;
}

/* Section Common Styles */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--primary-color);
}

.section-header h2 {
    font-size: 24px;
    color: var(--dark-color);
    position: relative;
    padding-left: 15px;
}

.section-header h2::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 24px;
    background: var(--primary-color);
    border-radius: 2px;
}

.section-header h2 i {
    margin-right: 10px;
    color: var(--primary-color);
}

.more-link {
    color: var(--primary-color);
    font-size: 14px;
}

.more-link:hover {
    color: var(--accent-color);
}

/* News Section */
.news-section {
    padding: 50px 0;
}

.news-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 25px;
}

.news-card {
    background: var(--white);
    padding: 25px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.news-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
}

.news-card.highlight {
    grid-column: 1;
    grid-row: 1 / 3;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
}

.news-card.highlight .news-date {
    color: rgba(255,255,255,0.8);
}

.news-card.highlight h3 a {
    color: var(--white);
}

.news-card.highlight p {
    color: rgba(255,255,255,0.9);
}

.news-date {
    font-size: 13px;
    color: var(--gray);
    margin-bottom: 10px;
}

.news-card h3 {
    font-size: 16px;
    line-height: 1.6;
    margin-bottom: 10px;
}

.news-card h3 a:hover {
    color: var(--primary-color);
}

.news-card p {
    font-size: 14px;
    color: var(--gray);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Dual Section - Academic & Notice side by side */
.dual-section {
    padding: 50px 0;
}

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

.dual-col {
    min-width: 0;
}

/* Academic Section */
.academic-section {
    padding: 0;
    background: transparent;
}

.academic-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.academic-item {
    display: flex;
    align-items: center;
    gap: 20px;
    background: var(--white);
    padding: 20px 25px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.academic-item:hover {
    transform: translateX(10px);
    box-shadow: 0 6px 25px rgba(0,0,0,0.1);
}

.academic-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 20px;
    flex-shrink: 0;
}

.academic-content h4 {
    font-size: 16px;
    color: #333;
    margin-bottom: 5px;
}

.academic-content .speaker,
.academic-content .time {
    font-size: 13px;
    color: var(--gray);
}

/* Platform Section */
.platform-section {
    padding: 50px 0;
}

.platform-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.platform-card {
    background: var(--white);
    padding: 30px 20px;
    border-radius: 10px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-top: 4px solid var(--primary-color);
}

.platform-card:hover {
    transform: translateY(-8px);
    border-top-color: var(--accent-color);
}

.platform-card i {
    font-size: 42px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.platform-card h4 {
    font-size: 15px;
    color: #333;
    margin-bottom: 15px;
    line-height: 1.5;
}

.platform-card a {
    display: inline-block;
    color: var(--primary-color);
    font-size: 13px;
    padding: 8px 20px;
    border: 1px solid var(--primary-color);
    border-radius: 20px;
}

.platform-card a:hover {
    background: var(--primary-color);
    color: var(--white);
}

/* Party Section */
.party-section {
    padding: 50px 0;
    background: linear-gradient(135deg, #fa2803 0%, #f8a83f 100%);
}

.party-section .section-header h2 {
    color: var(--white);
}

.party-section .section-header h2::before {
    background: #ff6b35;
}

.party-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.party-card {
    background: rgba(255,255,255,0.1);
    padding: 25px;
    border-radius: 10px;
    backdrop-filter: blur(10px);
    transition: var(--transition);
}

.party-card:hover {
    background: rgba(255,255,255,0.15);
    transform: translateY(-5px);
}

.party-card .news-date {
    color: rgba(255,255,255,0.7);
}

.party-card h3 {
    font-size: 15px;
    color: var(--white);
}

.party-card h3 a:hover {
    color: var(--accent-color);
}

/* Notice Section - 与学术报告风格一致 */
.notice-section {
    padding: 0;
    background: transparent;
}

.notice-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.notice-item {
    display: flex;
    align-items: center;
    gap: 20px;
    background: var(--white);
    padding: 20px 25px;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.notice-item:hover {
    transform: translateX(10px);
    box-shadow: 0 6px 25px rgba(0,0,0,0.1);
}

.notice-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--accent-color), #ff8c5a);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 20px;
    flex-shrink: 0;
}

.notice-content h4 {
    font-size: 16px;
    margin-bottom: 5px;
}

.notice-content h4 a:hover {
    color: var(--primary-color);
}

.notice-content .time {
    font-size: 13px;
    color: var(--gray);
}

/* Graduation Section - 走马灯 */
.graduation-section {
    padding: 50px 0;
    background: var(--light-gray);
    overflow: hidden;
}

.marquee-container {
    overflow: hidden;
    width: 100%;
    padding: 20px 0;
}

.marquee-track {
    display: flex;
    gap: 20px;
    animation: marquee-scroll 30s linear infinite;
    width: max-content;
}

.marquee-track:hover {
    animation-play-state: paused;
}

.marquee-item {
    flex-shrink: 0;
    width: 280px;
    height: 200px;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.marquee-item:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
}

.marquee-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.marquee-item:hover img {
    transform: scale(1.1);
}

@keyframes marquee-scroll {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-50%);
    }
}

/* Footer */
.footer {
    background: #1a1a2e;
    color: #ccc;
    padding: 50px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 30px;
}

.footer-section h4 {
    color: var(--white);
    font-size: 18px;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
}

.footer-section h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background: var(--primary-color);
}

.footer-section p {
    margin-bottom: 10px;
    font-size: 14px;
}

.footer-section p i {
    margin-right: 10px;
    width: 16px;
}

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

.footer-section ul li a {
    font-size: 14px;
}

.footer-section ul li a:hover {
    color: var(--primary-color);
}

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

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
}

.social-links a:hover {
    background: var(--primary-color);
    color: var(--white);
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
    font-size: 13px;
}

.footer-bottom p {
    margin: 5px 0;
}

/* Responsive */
@media (max-width: 992px) {
    .quick-links-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .news-grid {
        grid-template-columns: 1fr;
    }
    
    .news-card.highlight {
        grid-row: auto;
    }
    
    .dual-columns {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .platform-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .party-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .marquee-item {
        width: 240px;
        height: 170px;
    }
}

@media (max-width: 768px) {
    .main-nav {
        display: none;
    }
    
    .hero-slider {
        height: 300px;
    }
    
    .slide-content h1 {
        font-size: 28px;
    }
    
    .slide-content p {
        font-size: 16px;
    }
    
    .quick-links-grid,
    .platform-grid {
        grid-template-columns: 1fr;
    }
    
    .header-top {
        flex-direction: column;
        gap: 15px;
    }
    
    .search-box input {
        width: 140px;
    }
    
    .marquee-item {
        width: 200px;
        height: 150px;
    }
}