* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

:root {
    --primary-blue: #0A2463;
    --accent-red: #E63946;
    --accent-teal: #2A9D8F;
    --accent-yellow: #E9C46A;
    --accent-blue: #264653;
    --tab-life: #2A6F66;
    --tab-health: #2554B7;
    --tab-sustain: #D4E157;
    --text-dark: #000000;
    --text-light: #FFFFFF;
    --bg-light: #FFFFFF;
    --bg-dark: #000000;
    --transition: all 0.35s cubic-bezier(0.32, 0.01, 0.15, 1);
}

html {
    scroll-behavior: smooth;
}

body {
    color: var(--text-dark);
    background: var(--bg-light);
    line-height: 1.6;
    overflow-x: hidden;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ========== 导航栏 ========== */
.navbar {
    position: sticky;
    top: 0;
    width: 100%;
    /* 加深版水平渐变，右侧更有质感 */
    background: linear-gradient(90deg, #ffffff 0%, #eef5ff 100%);
    border-bottom: 5px solid var(--primary-blue);
    z-index: 999;
    box-shadow: 0 3px 12px rgba(35, 89, 153, 0.06);
    transition: var(--transition);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo {
    /* 1. 设置背景图（替换为你的图片路径） */
    background: url("../img/LOGO.png") no-repeat center / contain;
    /* 2. 隐藏原文字 */
    text-indent: -9999px;
    /* 3. 必须设置宽高（根据你的logo尺寸调整，示例宽100px高40px） */
    width: 130px;
    height: 45px;
    /* 若原样式有字体样式，需清空 */
    font-size: 0;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 28px;
    align-items: center;
}

.nav-menu a {
    font-size: 16px;
    font-weight: 500;
    position: relative;
}

.nav-menu a::after {
    content: "";
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-blue);
    transition: var(--transition);
}

.nav-menu a:hover::after {
    width: 100%;
}

.nav-icons {
    display: flex;
    gap: 24px;
    align-items: center;
    font-size: 22px;
    cursor: pointer;
}

/* 汉堡菜单按钮：无按钮感，纯图标 */
#menuBtn {
    background: transparent !important;
    border: none !important;
    color: inherit;
    font-size: 24px;
    cursor: pointer;
    padding: 0;
    line-height: 1;
}

#menuBtn:hover {
    color: var(--primary-blue);
}

/* 修复语言按钮样式 */
.lang-switch {
    padding: 6px 14px;
    background: #235999;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s;
}
.lang-switch:hover {
    background: #1a477d;
}

/* 多语言适配 */
body.lang-en .zh { display: none; }
body.lang-zh .en { display: none; }

/* 适配你的多语言：和你按钮的逻辑统一 */
body.lang-en .zh {
    display: none;
}
body.lang-zh .en {
    display: none;
}

/* 默认中文隐藏，英文显示；切换自动互换 */
.en {display: block;}
.zh {display: none;}
body.cn .en {display: none;}
body.cn .zh {display: block;}

/* ========== 期刊介绍区域 ========== */
.journals-intro {
    padding: 56px 24px;
    max-width: 1200px;
    margin: 0 auto;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 1s 0.4s forwards;
}

.journals-intro h2 {
    font-size: 32px;
    color: var(--primary-blue);
    margin-bottom: 24px;
    font-weight: 700;
}

.journals-intro p {
    font-size: 16px;
    line-height: 1.7;
    color: #333;
    margin-bottom: 32px;
}

#Benefits{
    margin-top: 90px;
    background-color: #eeeeee;
    padding: 10px 10px 3px 10px;
}

.content{
    margin-top: 90px;
}

.click{
    color: red;
}

/* ========== 页脚 ========== */
.footer {
    background: black;
    color: var(--text-light);
    padding: 60px 24px;
    margin-top: 60px;
}

#footitle{
    display: block;
    width: 100%;
    text-align: center;
    margin: 0 0 50px 0;
}
.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 36px;
}

.footer-logo {
    /* 1. 设置背景图（替换为你的图片路径） */
    background: url("../img/BottomLogo.png") no-repeat center / contain;
    /* 2. 隐藏原文字 */
    text-indent: -9999px;
    /* 3. 必须设置宽高（根据你的logo尺寸调整，示例宽100px高40px） */
    width: 290px;
    height: 120px;
    /* 若原样式有字体样式，需清空 */
    font-size: 0;
    margin-bottom: 40px;
    margin-right: 10px;
}

.footer-social {
    display: flex;
    gap: 16px;
    font-size: 24px;
    margin-bottom: 22px;
}

.footer-info {
    font-size: 14px;
    line-height: 1.6;
    opacity: 0.9;
    margin-left: 35px;
}

.footer-column {
    margin-right: 50px;
}

.footer-column h4 {
    font-size: 18px;
    margin-bottom: 18px;
    font-weight: 600;
}

.footer-form {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.footer-form input {
    padding: 13px;
    font-size: 15px;
    border: none;
    border-radius: 4px;
    outline: none;
}

.footer-form .btn {
    background: var(--text-light);
    color: var(--primary-blue);
    align-self: flex-start;
    border: none;
    cursor: pointer;
    padding: 13px 38px;
    font-size: 16px;
    font-weight: 600;
    border-radius: 4px;
    transition: var(--transition);
}

.footer-form .btn:hover {
    background: #f0f0f0;
    transform: translateY(-2px);
}

#PAL{
    width: 100%;
    background-color: darkblue;
    color: white;
    text-align: center;
    padding: 13px 0;
}

#PAL{
    width: 100%;
    background-color: darkblue;
    color: white;
    text-align: center;
    padding: 13px 0;
}

/* ========== 返回顶部 ========== */
.back-to-top {
    position: fixed;
    bottom: 36px;
    right: 36px;
    width: 52px;
    height: 52px;
    background: var(--primary-blue);
    color: var(--text-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    opacity: 0;
    visibility: hidden;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 18px rgba(0,0,0,0.2);
}

#emailto{
    padding: 10px 26px;
    background-color: whitesmoke;
    color: black;
    border: none;
    border-radius: 5px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    cursor: pointer;
    font-size: 16px;
    transition: 0.3s ease;
}
/* 侧边栏链接样式重置，完美还原原设计 */
.side-nav-menu ul li a {
    /* 核心：去掉默认下划线，继承原li的所有样式 */
    text-decoration: none;
    /* 继承父元素li的文字颜色，避免链接变蓝 */
    color: inherit;
    /* 继承父元素的字体、行高，避免间距错乱 */
    font: inherit;
    /* 让a标签占满整个li的点击区域，点击更友好 */
    display: block;
    /* 保持原有的内边距，和li完全对齐 */
    padding: inherit;
}

/* 可选：hover效果（和原设计风格统一，不影响整齐度） */
.side-nav-menu ul li a:hover {
    opacity: 0.8;
    transition: opacity 0.3s ease;
}
/* ========== 动画 ========== */
@keyframes fadeUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ========== 移动端适配 ========== */
@media (max-width: 900px) {
    /* 导航栏 */
    /* 隐藏默认菜单 */
    .nav-menu {
        display: none;
        position: absolute;
        top: 80px;
        left: 0;
        width: 100%;
        background: white;
        flex-direction: column;
        padding: 20px;
        gap: 16px;
        box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    }
    /* 菜单展开时显示 */
    .nav-menu.show {
        display: flex;
    }
    /* 汉堡按钮样式 */
    #menuBtn {
        border: none;
        background: transparent;
        font-size: 24px;
        cursor: pointer;
    }

    #Registration {
        margin-left: 8px;
        font-size: 12px;
        padding: 6px 10px;
    }
    .lang-switch {
        padding: 6px 8px;
        font-size: 12px;
    }

    /* Hero 标题区域 */
    .hero {
        padding: 50px 15px;
        text-align: center;
    }
    .hero h1 {
        font-size: 26px;
    }
    .hero p {
        font-size: 16px;
        white-space: normal;
        position: static;
        transform: none;
    }

    /* 左右布局 → 全部改为上下布局 */
    .win,
    .introduction,
    #park,
    #accommodation {
        flex-direction: column;
        padding: 0 15px;
    }
    .win .left,
    .win .right {
        flex: 0 0 100%;
        margin-bottom: 20px;
    }

    /* 子主题卡片 */
    .Sub-Themes {
        flex-direction: column;
        align-items: center;
    }
    .Sub-Themes .card {
        width: 100%;
        max-width: 380px;
    }

    /* 嘉宾卡片网格 */
    .grid {
        grid-template-columns: 1fr;
        padding: 0 15px;
    }

    /* 二维码区域 */
    #STR,
    #myflex {
        flex-direction: column;
        gap: 40px;
        align-items: center;
    }
    #STR > div,
    #myflex > div {
        width: 100%;
        text-align: center;
    }
    #SCR,
    #SCRN,
    #QRC {
        margin: 0 auto;
    }

    /* 图片自适应 */
    img {
        max-width: 100% !important;
        height: auto !important;
    }

    /* 表格手机优化 */
    table {
        font-size: 12px;
    }
    table th,
    table td {
        padding: 6px 4px;
        word-break: break-word;
    }

    /* 页脚 */
    #footitle {
        text-align: center !important;
    }
    #footitle h1 {
        text-align: center !important;
    }

    .footer-container {
        display: flex !important;
        flex-direction: column !important;
        align-items: center !important;
        text-align: center !important;
    }

    .footer-column {
        width: 100% !important;
        margin-right: 0 !important;
        text-align: center !important;
    }

    .footer-column h4 {
        text-align: center !important;
    }

    .footer-logo {
        margin: 0 auto 40px auto !important;
    }

    .footer-form {
        align-items: center !important;
        text-align: center !important;
    }

    .footer-form button {
        align-self: center !important;
    }

    /*标题居中*/
    h2 {
        text-align: center !important;
    }
    /* 锁定你页面里所有模块里的h2，防止被原有样式覆盖 */
    .win h2,
    .Sub-Themes h2,
    #more h2,
    #date h2,
    #OPC h2,
    #publication h2,
    #registrationfees h2,
    #pay h2,
    #submission h2,
    .journals-intro h2,
    .grid h2 {
        text-align: center !important;
    }
}

/* 更小屏幕手机 */
@media (max-width: 480px) {
    .hero h1 {
        font-size: 24px;
    }
    .hero p {
        font-size: 15px;
    }
    .bar {
        padding: 14px;
        font-size: 16px;
    }
    .con {
        padding: 15px;
    }
    .modal {
        width: 95%;
        padding: 25px 15px;
    }
    .qr-box img {
        width: 140px;
        height: 140px;
    }
}