/* —— 全局重置与基础样式 —— */
html, body {
    max-width: 100%;
    overflow-x: hidden;
    margin: 0;
    padding: 0;
}

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

body {
    font-family: "Arial", sans-serif;
    background: #fafafa;
    color: #333;
    line-height: 1.6;
}

/* —— 主题色变量 —— */
:root {
    --primary: #102a54;
    --accent: #c39528;
    --purple: #5b4b8a;
}

/* —— 统一的容器宽度 —— */
.container,
.t_header,
.nav,
.wrapper {
    max-width: 1360px;
    margin: 0 auto;
    padding-left: 16px;
    padding-right: 16px;
}

/* —— 顶部标题栏 —— */
.t_header {
    background: var(--primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 16px;
}

.t_header .logo {
    height: 40px;
    width: auto;
}

.t_header h1 {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: 0.02rem;
    flex: 1;
    text-align: center;
    text-transform: uppercase;
    font-family: "Times New Roman", Times, serif;
    padding: 0 10px;
}

/* —— 导航栏 —— */
.nav {
    background: #fff;
    border-top: 3px solid var(--accent);
    display: flex;
    flex-wrap: wrap;
    justify-content: space-evenly;
    position: relative;
    transition: transform 0.3s ease;
    padding: 10px 16px;
}

.nav a {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 120px;
    height: 60px;
    padding: 6px;
    font-size: 14px;
    text-align: center;
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
}

.nav a:hover {
    color: var(--accent);
}

/* —— 页面主体内容容器 —— */
.container {
    background: #FCFCFC;
    padding: 20px 16px;
}

/* —— 页面标题 —— */
header {
    text-align: center;
    margin-bottom: 30px;
}

header h1 {
    font-size: 48px;
    font-weight: bold;
    margin-bottom: 10px;
}

header .subtitle {
    font-size: 24px;
    font-weight: normal;
    color: var(--primary);
    margin-top: 0;
    margin-bottom: 0;
}

/* —— 主要内容区域 —— */
.content {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    margin-bottom: 30px;
}

.left-column {
    width: 70%;
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding-right: 10px;
}

.right-column {
    width: 30%;
    display: flex;
    flex-direction: column;
    gap: 10px;
    align-items: center;
    padding-left: 20px;
    border-left: 1px solid #eee;
}

.right-column img {
    width: 80%;
    height: auto;
    object-fit: contain;
}

/* —— 介绍和简介样式 —— */
.intro,
.university-intro {
    border: 1.5px solid #bbb;
    padding: 20px;
    margin-bottom: 30px;
    font-size: 1.6rem;
    background: #fff;
    border-radius: 6px;
}

.intro p,
.university-intro p {
    text-align: justify;
    margin-bottom: 1.2em;
    line-height: 1.8;
    color: #333;
    text-indent: 2em; /* 段首空两格 */
}

/* —— 历史会议介绍 —— */
.history-section {
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    padding: 28px 24px 24px 24px;
    margin-bottom: 30px;
    color: #222;
    font-size: 1.08rem;
    line-height: 1.8;
}

.history-section-title {
    background: var(--purple);
    color: #fff;
    font-size: 2rem;
    font-weight: bold;
    text-align: center;
    border-radius: 8px 8px 0 0;
    padding: 16px 0 12px 0;
    margin: -28px -24px 24px -24px;
    letter-spacing: 2px;
}

.history-section .subtitle {
    font-size: 2rem;
    font-weight: bold;
    text-align: center;
    margin-bottom: 18px;
}

.history-section-text {
    font-size: 1rem;
    margin-bottom: 8px;
}

.history-section b,
.history-section strong {
    font-weight: bold;
    color: #222;
}

/* —— 专题部分 —— */
.topic-section {
    background: #fff;
    border: 1.5px solid #bbb;
    border-radius: 6px;
    padding: 24px 18px 18px 18px;
    margin-bottom: 32px;
    width: 100%;
}

.topic-section-title {
    text-align: center;
    font-size: 1.8rem;
    font-weight: bold;
    margin-bottom: 18px;
    letter-spacing: 1px;
    color: var(--primary);
}

.topic-list {
    list-style: none;
    padding: 0;
    margin: 0;
    font-size: 1.5rem;
    line-height: 1.4;
}

.topic-list li {
    margin-bottom: 8px;
    text-align: left;
    padding-left: 1em;
    position: relative;
}

.topic-list li:before {
    content: "•";
    color: var(--accent);
    position: absolute;
    left: 0;
    font-weight: bold;
}

/* —— 图片画廊 —— */
.image-gallery {
    width: 100%;
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
}

.image-gallery img {
    width: 100%;
    height: auto;
    object-fit: cover;
    border: 1px solid #ccc;
    border-radius: 4px;
}

/* —— 右侧栏标题 —— */
.section-title {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: #222;
    margin-top: 32px;
    margin-bottom: 24px;
    gap: 12px;
}

.section-title-icon {
    width: 30px;
    height: 30px;
    display: inline-block;
}

.section-title-line {
    border-top: 4px dashed #a084ca;
    margin-bottom: 18px;
    margin-top: 0;
}

/* —— 移动端导航菜单 —— */
.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--primary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 10px;
    position: fixed;
    top: 10px;
    right: 10px;
    z-index: 1001;
    background: rgba(255, 255, 255, 0.9);
    border-radius: 4px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.nav-overlay.active {
    opacity: 1;
}

/* —— 响应式设计 —— */
@media (max-width: 1024px) {
    .container,
    .t_header,
    .nav,
    .wrapper {
        max-width: 100%;
        padding-left: 12px;
        padding-right: 12px;
    }

    .t_header h1 {
        font-size: 1.6rem;
    }

    header h1 {
        font-size: 36px;
    }
}

@media (max-width: 768px) {
    .content {
        flex-direction: column;
    }

    .left-column,
    .right-column {
        width: 100%;
        padding: 0;
        border: none;
    }

    .image-gallery {
        flex-direction: column;
    }

    .t_header {
        padding: 10px 12px;
    }

    .t_header .logo {
        height: 32px;
    }

    .t_header h1 {
        font-size: 1.3rem;
        padding: 0 8px;
    }

    header h1 {
        font-size: 28px;
    }

    header .subtitle {
        font-size: 18px;
    }

    /* 移动端导航菜单 */
    .menu-toggle {
        display: block;
    }

    .nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 300px;
        height: 100vh;
        background: #fff;
        z-index: 1000;
        flex-direction: column;
        padding: 60px 20px 20px;
        transition: right 0.3s ease;
        overflow-y: auto;
    }

    .nav.active {
        right: 0;
    }

    .nav-overlay {
        display: block;
        opacity: 0;
        visibility: hidden;
        transition: opacity 0.3s ease, visibility 0.3s ease;
    }

    .nav-overlay.active {
        opacity: 1;
        visibility: visible;
    }

    .nav a {
        display: block;
        width: 100%;
        height: auto;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        padding: 15px 25px;
        border-bottom: 1px solid #eee;
        text-align: left;
        font-size: 1.1rem;
    }

    .nav a:first-child {
        border-top: 1px solid #eee;
    }

    body.nav-open {
        overflow: hidden;
    }

    .intro,
    .university-intro {
        font-size: 1.2rem;
        padding: 16px;
    }

    .topic-list {
        font-size: 1.2rem;
    }

    .history-section {
        padding: 16px 12px 12px 12px;
    }

    .history-section-title {
        font-size: 1.5rem;
        padding: 12px 0 8px 0;
        margin: -16px -12px 16px -12px;
    }
}

@media (max-width: 480px) {
    .t_header h1 {
        font-size: 1.1rem;
    }

    header h1 {
        font-size: 24px;
    }

    header .subtitle {
        font-size: 16px;
    }

    .intro,
    .university-intro {
        font-size: 1rem;
        padding: 12px;
    }

    .topic-list {
        font-size: 1rem;
    }

    .history-section-title {
        font-size: 1.2rem;
    }

    .section-title {
        font-size: 1.2rem;
    }
}

/* —— 通用样式 —— */
img {
    max-width: 100%;
    height: auto;
}

/* 确保表格在移动端的显示 */
@media (max-width: 768px) {
    table {
        display: block;
        overflow-x: auto;
        white-space: nowrap;
    }
}