/* ============================================
   ICDM 2026 Website Stylesheet
   Academic Conference Style - Northeastern University Blue Theme
   ============================================ */

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

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

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

/* ============================================
   Header & Navigation
   ============================================ */
.header {
    background: linear-gradient(135deg, #18306a 0%, #204198 100%);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 3px solid #204198;
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80px;
}

.logo-section {
    display: flex;
    align-items: center;
}

.logo-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: #fff;
    transition: opacity 0.3s;
}

.logo-link:hover {
    opacity: 0.9;
}

.logo-image {
    height: 60px;
    max-width: 300px;
    width: auto;
    display: block;
    object-fit: contain;
}

.logo-icon {
    font-size: 32px;
    font-weight: bold;
    background: linear-gradient(135deg, #ffffff 0%, #e6f2ff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-right: 12px;
    letter-spacing: 2px;
}

.logo-text {
    font-size: 18px;
    font-weight: 600;
    line-height: 1.2;
}

.logo-text small {
    display: block;
    font-size: 12px;
    font-weight: 400;
    opacity: 0.9;
    margin-top: 2px;
}

.main-nav {
    flex: 1;
    display: flex;
    justify-content: flex-end;
}

.nav-menu {
    display: flex;
    list-style: none;
    align-items: center;
    gap: 5px;
}

.nav-menu > li > a {
    display: block;
    padding: 12px 18px;
    color: #fff;
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    transition: all 0.3s;
    border-radius: 4px;
    position: relative;
}

.nav-menu > li > a:hover {
    background-color: rgba(255, 255, 255, 0.15);
    transform: translateY(-1px);
}

/* 为有下拉菜单的导航项添加箭头 */
.nav-menu > li:has(.dropdown-menu),
.nav-menu > li.has-dropdown-menu {
    position: relative;
}

.nav-menu > li:has(.dropdown-menu) > a::after,
.nav-menu > li.has-dropdown-menu > a::after {
    content: "▼";
    font-size: 10px;
    margin-left: 5px;
    display: inline-block;
    transition: transform 0.3s;
}

.nav-menu > li:has(.dropdown-menu):hover > a::after,
.nav-menu > li.has-dropdown-menu:hover > a::after {
    transform: rotate(180deg);
}

/* 兼容不支持 :has() 的浏览器 */
.nav-menu > li .dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background: #fff;
    min-width: 220px;
    max-width: 300px;
    max-height: 400px;
    overflow-y: auto;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    border-radius: 6px;
    list-style: none;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s;
    margin-top: 5px;
    padding: 8px 0;
    border: 1px solid #e0e0e0;
    z-index: 1000;
}

/* 防止下拉菜单超出视口 */
.nav-menu > li:has(.dropdown-menu) {
    position: static;
}

@media (min-width: 769px) {
    .nav-menu > li:has(.dropdown-menu) {
        position: relative;
    }
    
    /* 如果菜单在右侧，自动调整到左侧显示，防止超出视口 */
    .nav-menu > li:last-child .dropdown-menu,
    .nav-menu > li:nth-last-child(2) .dropdown-menu {
        left: auto;
        right: 0;
    }
    
    /* 确保下拉菜单不会超出视口底部 */
    .nav-menu > li .dropdown-menu {
        max-height: calc(100vh - 100px);
        overflow-y: auto;
    }
}

.nav-menu > li:has(.dropdown-menu):hover .dropdown-menu,
.nav-menu > li.has-dropdown-menu:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu li a {
    display: block;
    padding: 10px 20px;
    color: #333;
    text-decoration: none;
    font-size: 14px;
    transition: all 0.2s;
}

.dropdown-menu li a:hover {
    background-color: #f0f7ff;
    color: #204198;
    padding-left: 25px;
}

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

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: #fff;
    border-radius: 2px;
    transition: all 0.3s;
}

/* ============================================
   Banner Section
   ============================================ */
.banner-section {
    position: relative;
    /*height: 600px;*/
    height: 400px;
    overflow: hidden;
    background: #18306a;
}

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

.banner-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 1s ease-in-out;
}

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

.banner-image {
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

.banner-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    /*background: linear-gradient(135deg, rgba(24, 48, 106, 0.7) 0%, rgba(32, 65, 152, 0.6) 100%);*/
}

.banner-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: #fff;
    z-index: 10;
    max-width: 900px;
    padding: 0 20px;
}

.banner-title {
    font-size: 56px;
    font-weight: 700;
    margin-bottom: 15px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    letter-spacing: 2px;
}

.banner-subtitle {
    font-size: 22px;
    margin-bottom: 20px;
    font-weight: 300;
    opacity: 0.95;
}

.banner-date {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 8px;
    color: #e6f2ff;
}

.banner-location {
    font-size: 20px;
    font-weight: 500;
    color: #cce6ff;
}

.banner-controls {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 15px;
    z-index: 20;
}

.banner-prev,
.banner-next {
    display: none;
    width: 45px;
    height: 45px;
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid rgba(255, 255, 255, 0.5);
    border-radius: 50%;
    color: #fff;
    font-size: 24px;
    cursor: pointer;
    transition: all 0.3s;
    backdrop-filter: blur(5px);
}

.banner-prev:hover,
.banner-next:hover {
    background: rgba(255, 255, 255, 0.3);
    border-color: rgba(255, 255, 255, 0.8);
    transform: scale(1.1);
}

.banner-indicators {
    display: flex;
    gap: 10px;
}

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

.indicator.active {
    background: #fff;
    width: 30px;
    border-radius: 6px;
}

/* ============================================
   Main Content Sections
   ============================================ */


.section-title {
    font-size: 36px;
    font-weight: 700;
    color: #204198;
    margin-bottom: 30px;
    text-align: center;
    position: relative;
    padding-bottom: 15px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, #204198, #18306a);
    border-radius: 2px;
}

.section-intro {
    text-align: center;
    font-size: 18px;
    color: #666;
    margin-bottom: 40px;
    font-style: italic;
}

/* Welcome Section */
.welcome-section {
    background: #fff;
    padding: 80px 0;
    border-bottom: 1px solid #e0e0e0;
}

.welcome-content {
    max-width: 100%;
    margin: 0 auto;
    font-size: 17px;
    line-height: 1.8;
    color: #444;
}

.welcome-content p {
    margin-bottom: 20px;
}

.welcome-content p:last-child {
    margin-bottom: 0;
}

/* Topics Section */
.topics-section {
    background: #f8f9fa;
    padding: 80px 0;
}

.topics-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
    margin-top: 40px;
}

.topic-item {
    background: #fff;
    padding: 30px 25px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.topic-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, #204198, #2d5bb8);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s;
}

.topic-item:hover::before {
    transform: scaleX(1);
}

.topic-item:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 25px rgba(32, 65, 152, 0.2);
}

.topic-icon {
    font-size: 40px;
    margin-bottom: 15px;
    display: inline-block;
    transition: transform 0.3s;
}

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

.topic-item h3 {
    font-size: 18px;
    color: #204198;
    margin-bottom: 12px;
    font-weight: 600;
    line-height: 1.4;
}

.topic-item p {
    font-size: 14px;
    line-height: 1.7;
    color: #666;
}

/* News Section */
.news-section {
    background: #fff;
    padding: 80px 0;
}

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

.news-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.news-item {
    display: flex;
    gap: 20px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 8px;
    border-left: 4px solid #204198;
    transition: all 0.3s;
    position: relative;
}

.news-item:hover {
    background: #f0f7ff;
    transform: translateX(5px);
}

.news-date {
    min-width: 100px;
    font-size: 14px;
    color: #204198;
    font-weight: 600;
    padding-top: 2px;
}

.news-content {
    flex: 1;
}

.news-title {
    font-size: 18px;
    font-weight: 600;
    color: #204198;
    margin-bottom: 8px;
}

.news-title a {
    color: #204198;
    text-decoration: none;
    transition: color 0.2s;
}

.news-title a:hover {
    color: #18306a;
}

.news-content p {
    font-size: 15px;
    color: #666;
    line-height: 1.6;
}

.news-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: #ff4444;
    color: #fff;
    font-size: 11px;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Announcements Box */
.announcements-box {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 8px;
    border: 2px solid #e0e0e0;
    position: sticky;
    top: 100px;
}

.box-title {
    font-size: 22px;
    color: #204198;
    margin-bottom: 20px;
    font-weight: 600;
    padding-bottom: 10px;
    border-bottom: 2px solid #204198;
}

.announcements-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.announcements-list li {
    padding-left: 20px;
    position: relative;
}

.announcements-list li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: #204198;
    font-weight: bold;
}

.announcements-list li a {
    color: #333;
    text-decoration: none;
    font-size: 14px;
    line-height: 1.6;
    transition: color 0.2s;
    display: block;
}

.announcements-list li a:hover {
    color: #204198;
    text-decoration: underline;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: #18306a;
    color: #fff;
    padding: 50px 0 20px;
    margin-top: 60px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-section h4 {
    font-size: 18px;
    margin-bottom: 15px;
    color: #e6f2ff;
}

.footer-section p {
    font-size: 14px;
    line-height: 1.8;
    color: #cce6ff;
}

.footer-section ul {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px 20px;
}

/* 处理 WebPlus 生成时没有 ul 包裹的情况 */
.footer-section > li {
    list-style: none;
    margin-bottom: 10px;
}

.footer-section ul li,
.footer-section > li {
    margin-bottom: 0;
}

/* 为没有 ul 的情况添加两列布局 */
.footer-section[frag="窗口91"] {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px 20px;
}

.footer-section[frag="窗口91"] > h4 {
    grid-column: 1 / -1;
    margin-bottom: 15px;
}

.footer-section[frag="窗口91"] > li {
    margin-bottom: 0;
}

.footer-section ul li a,
.footer-section > li a {
    color: #cce6ff;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.2s;
}

.footer-section ul li a:hover,
.footer-section > li a:hover {
    color: #fff;
    text-decoration: underline;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: #99ccff;
    font-size: 13px;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
    .topics-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    
    .banner-title {
        font-size: 42px;
    }
    
    .banner-subtitle {
        font-size: 18px;
    }
    
    .content-layout {
        grid-template-columns: 1fr;
    }
    
    .announcements-box {
        position: static;
    }
}

@media (max-width: 768px) {
    .header-container {
        height: auto;
        padding: 15px 20px;
    }
    
    .logo-image {
        height: 50px;
        max-width: 250px;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .main-nav {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: #18306a;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s;
    }
    
    .main-nav.mobile-open {
        max-height: calc(100vh - 80px);
        overflow-y: auto;
        overflow-x: hidden;
        height: auto;
    }
    
    .nav-menu {
        flex-direction: column;
        width: 100%;
        padding: 0;
        gap: 0;
        display: flex;
        box-sizing: border-box;
    }
    
    .nav-menu > li {
        width: 100%;
        display: flex;
        flex-direction: column;
        box-sizing: border-box;
    }
    
    /* 手机版：一级菜单项样式 */
    .nav-menu > li > a {
        padding: 15px 20px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        display: block;
        color: #fff;
        text-decoration: none;
        font-size: 15px;
        font-weight: 500;
        transition: background-color 0.2s;
        width: 100%;
    }
    
    .nav-menu > li > a:hover {
        background-color: rgba(255, 255, 255, 0.1);
    }
    
    /* 移除展开/收起图标 */
    .nav-menu > li:has(.dropdown-menu) > a::after,
    .nav-menu > li.has-dropdown-menu > a::after {
        display: none;
    }
    
    /* 手机版：二级菜单直接显示，不隐藏 */
    .nav-menu > li .dropdown-menu {
        position: static !important;
        opacity: 1 !important;
        visibility: visible !important;
        transform: none !important;
        box-shadow: none;
        background: rgba(0, 0, 0, 0.3) !important;
        margin: 0 !important;
        border: none;
        border-radius: 0;
        max-height: none !important;
        overflow: visible !important;
        padding: 10px 0 !important;
        list-style: none;
        display: block !important;
        min-width: auto !important;
        width: 100% !important;
        max-width: 100% !important;
        box-sizing: border-box !important;
    }
    
    /* 手机版：二级菜单项样式 */
    .dropdown-menu li {
        width: 100% !important;
        margin: 0;
        box-sizing: border-box;
    }
    
    .dropdown-menu li a {
        display: block;
        padding: 12px 20px 12px 40px;
        color: #e6f2ff !important;
        text-decoration: none;
        font-size: 14px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        transition: background-color 0.2s;
        background-color: transparent;
        width: 100% !important;
        box-sizing: border-box;
    }
    
    .dropdown-menu li:last-child a {
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    .dropdown-menu li a:hover {
        background-color: rgba(255, 255, 255, 0.1);
        color: #fff !important;
    }
    
    .banner-section {
        height: 400px;
    }
    
    .banner-title {
        font-size: 32px;
    }
    
    .banner-subtitle {
        font-size: 16px;
    }
    
    .banner-date {
        font-size: 18px;
    }
    
    .banner-location {
        font-size: 16px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .topics-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    
    .topic-item {
        padding: 25px 20px;
    }
    
    .topic-icon {
        font-size: 35px;
        margin-bottom: 12px;
    }
    
    .topic-item h3 {
        font-size: 16px;
    }
    
    .topic-item p {
        font-size: 13px;
    }
    
    .welcome-content {
        font-size: 16px;
    }
    
    .news-item {
        flex-direction: column;
        gap: 10px;
    }
    
    .news-date {
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .topics-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .topic-icon {
        font-size: 32px;
    }
    
    .logo-image {
        height: 40px;
        max-width: 200px;
    }
    
    .banner-section {
        height: 350px;
    }
    
    .banner-title {
        font-size: 24px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
   
    
    .welcome-section,
    .topics-section,
    .news-section {
        padding: 50px 0;
    }
}

/* ============================================
   Detail Page Styles
   ============================================ */
.breadcrumb {
    padding: 20px 0;
    font-size: 14px;
    color: #666;
    border-bottom: 1px solid #e0e0e0;
    margin-bottom: 30px;
}

.breadcrumb span {
    color: #18306a;
    font-weight: 500;
}

.article-detail {
    background: #fff;
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    margin-bottom: 40px;
}

.article-title {
    font-size: 32px;
    color: #18306a;
    margin-bottom: 15px;
    line-height: 1.4;
    font-weight: 600;
}

.article-subtitle {
    font-size: 20px;
    color: #666;
    margin-bottom: 20px;
    font-weight: 400;
}

.article-meta {
    display: flex;
    gap: 20px;
    padding: 15px 0;
    border-top: 1px solid #e0e0e0;
    border-bottom: 1px solid #e0e0e0;
    margin-bottom: 30px;
    font-size: 14px;
    color: #666;
    flex-wrap: wrap;
}

.article-meta span {
    display: flex;
    align-items: center;
}

.article-content {
    margin-top: 30px;
}

.article-body {
    font-size: 16px;
    line-height: 1.8;
    color: #333;
}

.article-body p {
    margin-bottom: 20px;
}

.article-body img {
    max-width: 100%;
    height: auto;
    border-radius: 6px;
    margin: 20px 0;
}

.article-body h1,
.article-body h2,
.article-body h3,
.article-body h4 {
    color: #18306a;
    margin-top: 30px;
    margin-bottom: 15px;
    font-weight: 600;
}

.article-body h1 { font-size: 28px; }
.article-body h2 { font-size: 24px; }
.article-body h3 { font-size: 20px; }
.article-body h4 { font-size: 18px; }

.article-body ul,
.article-body ol {
    margin: 20px 0;
    padding-left: 30px;
}

.article-body li {
    margin-bottom: 10px;
}

.article-body a {
    color: #204198;
    text-decoration: none;
    border-bottom: 1px solid #204198;
    transition: color 0.2s;
}

.article-body a:hover {
    color: #18306a;
    border-bottom-color: #18306a;
}

/* ============================================
   List Page Styles
   ============================================ */
.column-header {
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid #18306a;
}

.column-title {
    font-size: 28px;
    color: #18306a;
    font-weight: 600;
    margin: 0;
}

.news-list-section {
    background: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    margin-bottom: 40px;
}

.news-list-items {
    list-style: none;
    padding: 0;
    margin: 0;
}

.news-list-items .news-item {
    padding: 20px 0;
    border-bottom: 1px solid #e0e0e0;
    transition: background-color 0.2s;
}

.news-list-items .news-item:last-child {
    border-bottom: none;
}

.news-list-items .news-item:hover {
    background-color: #f8f9fa;
    padding-left: 10px;
    padding-right: 10px;
    margin-left: -10px;
    margin-right: -10px;
    border-radius: 4px;
}

.news-link {
    display: flex;
    justify-content: space-between;
    align-items: center;
    text-decoration: none;
    color: #333;
    gap: 20px;
}

.news-title {
    font-size: 16px;
    color: #18306a;
    font-weight: 500;
    flex: 1;
    transition: color 0.2s;
}

.news-link:hover .news-title {
    color: #204198;
}

.news-date {
    font-size: 14px;
    color: #999;
    white-space: nowrap;
}

@media (max-width: 768px) {
    .article-detail {
        padding: 25px 20px;
    }
    
    .article-title {
        font-size: 24px;
    }
    
    .article-subtitle {
        font-size: 18px;
    }
    
    .article-meta {
        flex-direction: column;
        gap: 10px;
    }
    
    .column-title {
        font-size: 24px;
    }
    
    .news-list-section {
        padding: 20px 15px;
    }
    
    .news-link {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    
    .news-date {
        font-size: 12px;
    }
}



.column-title {
    font-size: 36px;
    font-weight: 700;
    color: #204198;
    margin-bottom: 30px;
    text-align: center;
    position: relative;
    padding-bottom: 15px;
}

.column-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, #204198, #18306a);
    border-radius: 2px;
}