/* ===== 基础重置和全局样式 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

/* ===== 顶部绿色通栏 ===== */
.top-header {
    background: linear-gradient(135deg, #1a5c3a 0%, #2e8b57 100%);
    color: #fff;
    padding: 4px 0;
}

.top-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.top-header-left {
    flex: 1;
}

.site-title-top {
    font-size: 14px;
    color: rgba(255,255,255,0.9);
    letter-spacing: 0.5px;
}

.top-header-right {
    flex: 1;
    display: flex;
    justify-content: flex-end;
    align-items: center;
    gap: 20px;
}

.top-link {
    color: #fff;
    font-size: 14px;
    padding: 6px 12px;
    border: 1px solid rgba(255,255,255,0.4);
    border-radius: 4px;
    transition: all 0.3s;
}

.top-link:hover {
    background-color: rgba(255,255,255,0.1);
    border-color: #fff;
}

.btn-register-top {
    background-color: #ffd700;
    color: #1a5c3a;
    font-weight: bold;
    border: none;
    padding: 6px 16px;
}

.btn-register-top:hover {
    background-color: #ffed4e;
}

/* ===== 主横幅区域 ===== */
.hero-section {
    background: linear-gradient(135deg, #1a5c3a 0%, #2e8b57 100%);
    padding: 20px 0;
    position: relative;
}

.hero-section .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.hero-left {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 15px;
}

.hero-logo-img {
    max-width: 200px;
    height: auto;
    display: block;
}

.hero-year {
    font-size: 42px;
    font-weight: bold;
    color: #fff;
    letter-spacing: 2px;
    text-shadow: 2px 2px 6px rgba(0,0,0,0.3);
}

.hero-right {
    flex: 1;
    text-align: right;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 15px;
}

.hero-location-date {
    font-size: 26px;
    color: #fff;
    font-weight: bold;
    letter-spacing: 1px;
}

.hero-theme {
    font-size: 22px;
    color: #ffd700;
    font-weight: bold;
    letter-spacing: 0.5px;
}

/* ===== 白色圆角导航栏 ===== */
.navbar-wrapper {
    background-color: #f5f5f5;
    padding: 8px 0 0;
}

.navbar {
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: relative;
}

.navbar .container {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0 20px;
}

.navbar-brand {
    display: none;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 5px;
}

.nav-menu > li {
    position: relative;
}

.nav-menu > li > a {
    display: block;
    padding: 18px 20px;
    color: #333;
    font-size: 17px;
    font-weight: 600;
    transition: all 0.3s;
    border-bottom: 3px solid transparent;
}

.nav-menu > li > a:hover,
.nav-menu > li.active > a {
    color: #1a5c3a;
    border-bottom-color: #1a5c3a;
}

/* 下拉菜单 */
.nav-menu > li .dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #fff;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    min-width: 220px;
    display: none;
    z-index: 100;
    border-radius: 0 0 4px 4px;
}

.nav-menu > li:hover .dropdown {
    display: block;
}

.nav-menu > li .dropdown li a {
    display: block;
    padding: 12px 20px;
    color: #333;
    font-size: 14px;
    transition: all 0.3s;
    border-left: 3px solid transparent;
}

.nav-menu > li .dropdown li a:hover {
    background-color: #f5f5f5;
    color: #1a5c3a;
    border-left-color: #1a5c3a;
}

/* 汉堡菜单 */
.hamburger {
    display: none;
    cursor: pointer;
    font-size: 24px;
    padding: 10px;
}

.hamburger span {
    display: block;
    width: 25px;
    height: 3px;
    background-color: #1a5c3a;
    margin: 5px 0;
    transition: 0.3s;
}

/* ===== 横幅/Banner（纯图片/子页面标题） ===== */
.hero-banner {
    position: relative;
    width: 100%;
    background: linear-gradient(135deg, #1a5c3a 0%, #2e8b57 100%);
    color: #fff;
    text-align: center;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 120px;
}

.hero-banner-bg {
    width: 100%;
    height: auto;
    display: block;
}

.hero-banner::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.2);
    z-index: 1;
}

.hero-banner .hero-content {
    position: relative;
    z-index: 2;
    width: 100%;
    padding: 40px 20px;
    text-align: center;
}

.hero-banner .hero-title {
    font-size: 36px;
    font-weight: bold;
    margin: 0;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
    color: #fff;
    text-align: center;
}

/* ===== 内容区块 ===== */
.section {
    padding: 60px 0;
}

.section-title {
    font-size: 32px;
    color: #1a5c3a;
    text-align: center;
    margin-bottom: 40px;
    position: relative;
    padding-bottom: 15px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background-color: #ffd700;
}

.section-light {
    background-color: #f9f9f9;
}

/* ===== 欢迎信息 ===== */
.welcome-section {
    padding: 60px 0;
}

.welcome-content {
    max-width: 900px;
    margin: 0 auto;
    text-align: justify;
}

.welcome-content p {
    font-size: 16px;
    line-height: 1.8;
    margin-bottom: 20px;
    color: #555;
    text-align: justify;
}

/* ===== 主题列表 ===== */
.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    max-width: 1000px;
    margin: 0 auto;
}

.topic-card {
    background: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.topic-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.15);
}

.topic-card h3 {
    color: #1a5c3a;
    font-size: 18px;
    margin-bottom: 10px;
}

.topic-card .topic-number {
    display: inline-block;
    background-color: #1a5c3a;
    color: #fff;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    text-align: center;
    line-height: 30px;
    font-size: 14px;
    margin-right: 10px;
}

/* ===== 组织者信息 ===== */
.organizers-section {
    padding: 40px 0;
    background-color: #f5f5f5;
}

.organizers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    text-align: left;
}

.organizer-box {
    background: #fff;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    min-height: 180px;
}

.organizer-box h3 {
    color: #1a5c3a;
    font-size: 18px;
    margin-bottom: 15px;
    border-bottom: 2px solid #ffd700;
    padding-bottom: 10px;
}

.organizer-box p {
    font-size: 15px;
    color: #666;
    line-height: 1.8;
    text-align: left;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

/* ===== 讲者卡片 ===== */
.speakers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    max-width: 1100px;
    margin: 0 auto;
}

.speaker-card {
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 3px 12px rgba(0,0,0,0.1);
    transition: transform 0.3s;
    text-align: center;
}

.speaker-card:hover {
    transform: translateY(-5px);
}

.speaker-image {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background-color: #e0e0e0;
    margin: 30px auto 20px;
    overflow: hidden;
}

.speaker-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center top;
}

.speaker-card h3 {
    color: #1a5c3a;
    font-size: 20px;
    margin-bottom: 10px;
}

.speaker-card .speaker-title {
    color: #666;
    font-size: 14px;
    padding: 0 20px;
    margin-bottom: 15px;
}

.speaker-card .speaker-honor {
    color: #888;
    font-size: 13px;
    padding: 0 20px 30px;
    line-height: 1.6;
}

/* ===== 委员会列表 ===== */
.committee-section {
    padding: 60px 0;
}

.committee-group {
    margin-bottom: 50px;
}

.committee-group h3 {
    color: #1a5c3a;
    font-size: 24px;
    margin-bottom: 25px;
    padding-left: 15px;
    border-left: 4px solid #ffd700;
}

.committee-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 20px;
}

.committee-item {
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.committee-item h4 {
    color: #333;
    font-size: 16px;
    margin-bottom: 8px;
}

.committee-item p {
    color: #666;
    font-size: 14px;
}

/* ===== 重要日期 ===== */
.dates-section {
    padding: 60px 0;
    background-color: #fff;
    color: #333;
}

.dates-section .section-title {
    color: #1a5c3a;
}

.dates-section .section-title::after {
    background-color: #ffd700;
}

.dates-list {
    max-width: 800px;
    margin: 0 auto;
}

.date-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    background-color: #f9f9f9;
    border-radius: 8px;
    margin-bottom: 15px;
    border-left: 3px solid #1a5c3a;
}

.date-item .date-label {
    font-size: 16px;
    font-weight: bold;
    color: #333;
}

.date-item .date-value {
    font-size: 16px;
    color: #1a5c3a;
    font-weight: bold;
}

/* ===== 注册费用表格 ===== */
.fees-table {
    max-width: 800px;
    margin: 40px auto 0;
    overflow-x: auto;
}

.fees-table table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.fees-table th,
.fees-table td {
    padding: 15px;
    text-align: center;
    border: 1px solid #e0e0e0;
}

.fees-table th {
    background-color: #1a5c3a;
    color: #fff;
    font-weight: bold;
}

.fees-table tr:nth-child(even) {
    background-color: #f9f9f9;
}

/* ===== 酒店信息 ===== */
.hotel-section {
    padding: 60px 0;
}

.hotel-card {
    max-width: 900px;
    margin: 0 auto;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    overflow: hidden;
}

.hotel-content {
    padding: 30px;
}

.hotel-content h3 {
    color: #1a5c3a;
    font-size: 24px;
    margin-bottom: 15px;
}

.hotel-content p {
    font-size: 15px;
    color: #666;
    margin-bottom: 10px;
    line-height: 1.8;
}

.hotel-content a {
    color: #1a5c3a;
    text-decoration: underline;
}

.hotel-content a:hover {
    color: #2e8b57;
}

/* ===== 会议日程 ===== */
.schedule-section {
    padding: 60px 0;
}

.schedule-day {
    margin-bottom: 40px;
}

.schedule-day h3 {
    color: #1a5c3a;
    font-size: 22px;
    margin-bottom: 20px;
    padding: 15px;
    background-color: #f5f5f5;
    border-left: 4px solid #ffd700;
}

.schedule-table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
}

.schedule-table tr {
    border-bottom: 1px solid #e0e0e0;
}

.schedule-table td {
    padding: 15px;
    vertical-align: top;
}

.schedule-table td:first-child {
    width: 150px;
    font-weight: bold;
    color: #1a5c3a;
    background-color: #f9f9f9;
}

.schedule-table .session-title {
    font-weight: bold;
    color: #333;
}

.schedule-table .session-location {
    color: #888;
    font-size: 14px;
}

/* ===== 新闻列表 ===== */
.news-section {
    padding: 60px 0;
}

.news-list {
    max-width: 900px;
    margin: 0 auto;
}

.news-item {
    background: #fff;
    padding: 25px;
    margin-bottom: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    border-left: 4px solid #1a5c3a;
    transition: transform 0.3s;
}

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

.news-item h3 {
    color: #1a5c3a;
    font-size: 20px;
    margin-bottom: 10px;
}

.news-item .news-date {
    color: #888;
    font-size: 14px;
    margin-bottom: 10px;
}

.news-item p {
    color: #666;
    line-height: 1.8;
}

/* ===== 实地考察 ===== */
.fieldtrip-section {
    padding: 60px 0;
}

.fieldtrip-card {
    max-width: 900px;
    margin: 0 auto;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    padding: 40px;
}

.fieldtrip-card h3 {
    color: #1a5c3a;
    font-size: 24px;
    margin-bottom: 20px;
}

.fieldtrip-card p {
    font-size: 16px;
    color: #555;
    line-height: 1.8;
    margin-bottom: 15px;
}

/* ===== 页脚 ===== */
.footer {
    background: linear-gradient(135deg, #1a5c3a 0%, #2e8b57 100%);
    color: #fff;
    padding: 50px 0 30px;
}

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

.footer-section h3 {
    font-size: 18px;
    margin-bottom: 20px;
    border-bottom: 2px solid #ffd700;
    padding-bottom: 10px;
}

.footer-section p,
.footer-section a {
    color: #ccc;
    font-size: 14px;
    line-height: 2;
}

.footer-section a:hover {
    color: #ffd700;
}

/* 社交媒体图标 */
.social-icons {
    display: flex;
    gap: 15px;
    align-items: center;
}

.social-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    color: #ccc;
    transition: color 0.3s, transform 0.3s;
}

.social-icon:hover {
    color: #ffd700;
    transform: scale(1.1);
}

.social-icon svg {
    width: 24px;
    height: 24px;
}

.social-icon-img {
    width: 24px;
    height: 24px;
    transition: transform 0.3s;
}

.social-icon:hover .social-icon-img {
    transform: scale(1.1);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255,255,255,0.2);
    color: #aaa;
    font-size: 13px;
}

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

/* ===== 按钮 ===== */
.btn-register {
    display: inline-block;
    background-color: #ffd700;
    color: #1a5c3a;
    padding: 15px 40px;
    font-size: 18px;
    font-weight: bold;
    border-radius: 5px;
    transition: all 0.3s;
    box-shadow: 0 4px 6px rgba(0,0,0,0.2);
}

.btn-register:hover {
    background-color: #ffed4e;
    transform: translateY(-2px);
    box-shadow: 0 6px 10px rgba(0,0,0,0.25);
}

/* ===== 响应式设计 ===== */
@media (max-width: 768px) {
    .hamburger {
        display: block;
    }

    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background-color: #fff;
        flex-direction: column;
        transition: left 0.3s;
        overflow-y: auto;
        box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu > li > a {
        padding: 15px 20px;
        border-bottom: 1px solid #f0f0f0;
    }

    .nav-menu > li .dropdown {
        position: static;
        box-shadow: none;
        display: none;
    }

    .nav-menu > li .dropdown.show {
        display: block;
    }

    .top-header .container {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }

    .top-header-right {
        flex-direction: column;
        gap: 15px;
    }

    .hero-section .container {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }

    .hero-right {
        text-align: center;
        align-items: center;
    }

    .hero-logo-text {
        font-size: 36px;
    }

    .hero-location-date {
        font-size: 18px;
    }

    .section-title {
        font-size: 26px;
    }

    .topics-grid {
        grid-template-columns: 1fr;
    }

    .speakers-grid {
        grid-template-columns: 1fr;
    }

    .committee-list {
        grid-template-columns: 1fr;
    }

    .date-item {
        flex-direction: column;
        text-align: center;
        gap: 10px;
    }

    .schedule-table td:first-child {
        width: 100px;
    }
}

@media (max-width: 480px) {
    .hero-logo-text {
        font-size: 28px;
    }

    .hero-location-date {
        font-size: 16px;
    }

    .btn-register {
        padding: 12px 30px;
        font-size: 16px;
    }

    .section {
        padding: 40px 0;
    }
}