/* main.css - 已清理和优化 */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --light-color: #ecf0f1;
    --dark-color: #2c3e50;
    --text-color: #333;
    --text-light: #fff;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

p{
    margin-block-end: 0rem;
}

body {
    background-color: #f9f9f9;
    color: var(--text-color);
    line-height: 1.6;
}

/* ===== Header 样式 ===== */
/* ===== Header 样式 ===== */
.conference-title {
    display: flex;
    align-items: center;
    width: auto;
    font-weight: 500;
    color: #eceaea;
    white-space: nowrap;           /* 关键：禁止换行 */
    overflow: hidden;              /* 隐藏溢出 */
    text-overflow: clip;           /* 不显示省略号 */
    gap: 8px;                      /* 图片与文字间距 */
}

.conference-title .conference-logo {
    height: clamp(40px, 8vw, 80px);  /* 响应式高度 */
    flex-shrink: 0;                /* 图片不压缩 */
    margin-right: 0;               /* 用 gap 控制间距 */
}

.conference-title .logo {
    font-size: clamp(0.75rem, 2.2vw, 1.1rem); /* 响应式字体 */
    white-space: nowrap;
    overflow: hidden;
    text-overflow: clip;
    flex-shrink: 1;
    min-width: 0;
}

.title-width {
    width: auto;
}

header {
    background-color: var(--primary-color);
    color: var(--text-light);
    padding: 2px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.container {
    width: 90%;
    max-width: 100%;
    margin: 0 auto 1vh;
    /* === 流式字体方案 === */
    font-size: clamp(14px, 1.1vw + 0.4rem, 20px);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: clamp(14px, 1.1vw + 0.4rem, 20px);
}

.logo {
    font-size: x-large;
    font-weight: bold;
}

.logo span {
    color: var(--secondary-color);
}

/* ===== 导航样式 ===== */
nav ul {
    display: flex;
    list-style: none;
}

nav ul li {
    margin-left: 1.5rem;
}

nav ul li a {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
    padding: 0.5rem 0;
}

nav ul li a:hover {
    color: var(--secondary-color);
}

/* ===== 语言切换 ===== */
.language-switcher {
    display: flex;
    align-items: center;
}

.language-switcher button {
    background: none;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    padding: 0.5rem;
    margin-left: 0.5rem;
    font-weight: 500;
    transition: color 0.3s;
}

.language-switcher button.active {
    color: var(--secondary-color);
    border-bottom: 2px solid var(--secondary-color);
}

.language-switcher button:hover {
    color: var(--secondary-color);
}

.lang-zh {
    display: block;
}

.lang-en {
    display: none;
}

/* ===== 按钮样式 ===== */
.btn {
    display: inline-block;
    background-color: var(--secondary-color);
    color: var(--text-light);
    padding: 0.8rem 1.5rem;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 600;
    transition: background-color 0.3s;
    border: none;
    cursor: pointer;
}

.btn:hover {
    background-color: #2980b9;
}

/* ===== 章节标题 ===== */
.section-title {
    text-align: center;
    margin-bottom: 2rem;
    margin-top: 3rem;
    position: relative;
}

.section-title:after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background-color: var(--secondary-color);
    margin: 0.5rem auto;
}

/* ===== 内容网格 ===== */
.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

/* ===== 卡片样式 ===== */
.card {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    padding: 2rem;
    transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

/* ===== Footer 样式 ===== */
footer {
    background-color: var(--dark-color);
    color: var(--text-light);
    padding: 3rem 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1.5rem;
    font-size: 1.2rem;
}

.footer-section p, .footer-section a {
    color: #bdc3c7;
    margin-bottom: 0.8rem;
    display: block;
    text-decoration: none;
}

.footer-section a:hover {
    color: var(--secondary-color);
}

.copyright {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: #bdc3c7;
    font-size: 0.9rem;
}

/* ===== 响应式设计 ===== */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        text-align: center;
        gap: 0.5rem;
    }
    
    nav ul {
        margin-top: 1rem;
        justify-content: center;
        flex-wrap: wrap;
        gap: 0.3rem;
    }
    
    nav ul li {
        margin: 0.3rem 0.4rem;
        font-size: 0.75rem;
    }
    
    .conference-title {
        font-size: 0.85rem;
        max-width: 100%;
        justify-content: center;
    }
    
    .conference-title .conference-logo {
        height: 50px;
        margin-right: 6px;
    }
    
    .language-switcher button {
        padding: 0.3rem 0.4rem;
        font-size: 0.8rem;
        margin-left: 0.3rem;
    }
}

@media (max-width: 480px) {
    header {
        padding: 5px 0;
    }
    
    nav ul {
        gap: 0.2rem;
    }
    
    nav ul li {
        font-size: 0.65rem;
        margin: 0.2rem 0.2rem;
    }
    
    nav ul li a {
        padding: 0.3rem 0;
    }
    
    .conference-title {
        font-size: 0.75rem;
        flex-direction: column;
        text-align: center;
    }
    
    .conference-title .conference-logo {
        height: 40px;
        margin-bottom: 0.3rem;
        margin-right: 0;
    }
    
    .container {
        width: 98%;
    }
    
    .language-switcher {
        margin-top: 0.3rem;
    }
    
    .language-switcher button {
        padding: 0.25rem 0.3rem;
        font-size: 0.7rem;
        margin-left: 0.3rem;
    }
}

@media (max-width: 360px) {
    nav ul li {
        font-size: 0.6rem;
        margin: 0.15rem 0.15rem;
    }
    
    nav ul li a {
        padding: 0.25rem 0;
    }
    
    .conference-title .conference-logo {
        height: 35px;
    }
    
    .conference-title {
        font-size: 0.7rem;
    }
    
    .conference-title .logo {
        font-size: 0.7rem;
    }
    
    .language-switcher button {
        font-size: 0.65rem;
        padding: 0.2rem 0.25rem;
        margin-left: 0.25rem;
    }
    
    .container {
        width: 99%;
    }
}

/* 文件2中有，文件1中没有 */
.qr-code {
    text-align: center;
    padding: 1.5rem;
}
.qr-code img {
    max-width: 200px;
    margin-bottom: 1rem;
    border: 1px solid #eee;
    padding: 10px;
    background: white;
}

.page-hero {
    position: relative;
    text-align: center;
    color: #fff;
    margin-bottom: 2rem;
    padding: 3rem 0;
    background:
    linear-gradient(rgba(44, 62, 80, 0.8), rgba(44, 62, 80, 0.9)),
    url('../images/orange.PNG');
    background-size: cover;
    background-position: center;
}

.page-nav {
    display: flex;
    justify-content: center;
    margin: 2rem 0;
}
.page-nav a {
    margin: 0 1rem;
    padding: 0.5rem 1rem;
    background-color: var(--light-color);
    border-radius: 4px;
    text-decoration: none;
    color: var(--primary-color);
    transition: background-color 0.3s;
}

.page-nav a:hover {
    background-color: var(--secondary-color);
    color: white;
}

.qr-code {
    text-align: center;
    padding: 1.5rem;
}
.qr-code img {
    max-width: 200px;
    margin-bottom: 1rem;
    border: 1px solid #eee;
    padding: 10px;
    background: white;
}

.page-hero {
    position: relative;
    text-align: center;
    color: #fff;
    margin-bottom: 2rem;
    padding: 3rem 0;
    background:
    linear-gradient(rgba(44, 62, 80, 0.8), rgba(44, 62, 80, 0.9)),
    url('../images/orange.PNG');
    background-size: cover;
    background-position: center;
}

.page-nav {
    display: flex;
    justify-content: center;
    margin: 2rem 0;
}
.page-nav a {
    margin: 0 1rem;
    padding: 0.5rem 1rem;
    background-color: var(--light-color);
    border-radius: 4px;
    text-decoration: none;
    color: var(--primary-color);
    transition: background-color 0.3s;
}

.page-nav a:hover {
    background-color: var(--secondary-color);
    color: white;
}