/* 全局变量：黑白主题 */
:root {
    --bg: #ffffff;
    --text: #222222;
    --nav-bg: #f8f8f8;
    --nav-text: #222222;
    --hero-bg: #f0f0f0;
}

[data-theme="dark"] {
    --bg: #121212;
    --text: #e5e5e5;
    --nav-bg: #1e1e1e;
    --nav-text: #e5e5e5;
    --hero-bg: #1a1a1a;
    --icon-filter: invert(1);
}

/* 全局样式 */
body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: "Segoe UI", sans-serif;
}

/* 顶部导航栏 */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 40px;
    background: var(--nav-bg);
    border-bottom: 1px solid #ddd;
}

.nav-center a {
    margin: 0 16px;
    text-decoration: none;
    color: var(--nav-text);
    font-weight: 500;
}

.nav-center a:hover {
    opacity: 0.7;
}

.logo {
    font-size: 20px;
    font-weight: bold;
}

/* 主题切换按钮 */
.theme-btn {
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
}

/* 顶部 Banner */
.hero {
    padding: 100px 40px;
    text-align: center;
    background: var(--hero-bg);
}

.hero h1 {
    font-size: 40px;
    margin-bottom: 10px;
}

.hero p {
    font-size: 18px;
    opacity: 0.8;
}

/* 首页三大模块 */
.sections {
    display: flex;
    justify-content: center;
    gap: 30px;
    padding: 60px 40px;
    flex-wrap: wrap;
}

.section-card {
    background: var(--hero-bg);
    padding: 30px;
    border-radius: 10px;
    width: 280px;
    text-align: center;
    border: 1px solid #ddd;
    transition: 0.2s;
}

.section-card:hover {
    transform: translateY(-4px);
    opacity: 0.95;
}

.section-card h2 {
    margin-bottom: 10px;
}

.btn {
    display: inline-block;
    margin-top: 15px;
    padding: 8px 16px;
    background: var(--text);
    color: var(--bg);
    text-decoration: none;
    border-radius: 6px;
    font-size: 14px;
}

.btn:hover {
    opacity: 0.8;
}

/* 顶部 logo 图片 */
.logo-img {
    height: 40px;
    object-fit: contain;
}

/* 小号 Banner */
.small-hero {
    padding: 60px 40px;
}

/* 联系方式布局 */
.contact-container {
    max-width: 900px;
    margin: 40px auto;
    padding: 0 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    justify-content: center;
}

.contact-card {
    background: var(--hero-bg);
    padding: 25px;
    border-radius: 10px;
    width: 260px;
    border: 1px solid #ddd;
    text-align: center;
}

.contact-card h2 {
    margin-bottom: 10px;
    font-size: 20px;
}

.contact-info {
    font-weight: 600;
    margin-top: 10px;
}

/* 微信二维码 */
.qr-img {
    width: 160px;
    height: 160px;
    object-fit: cover;
    margin-top: 10px;
    border-radius: 6px;
}

/* 社交媒体图标区域 */
.social-icons {
    display: flex;
    justify-content: center;
    gap: 25px;
    margin-top: 15px;
}

/* 社交媒体 logo */
.social-logo {
    width: 40px;
    height: 40px;
    opacity: 0.85;
    transition: 0.2s;
    /* 修复10：深色模式下黑色SVG图标不可见，自动反色 */
    filter: var(--icon-filter, none);
}

.social-logo:hover {
    opacity: 1;
    transform: scale(1.05);
}

/* 关于我们页面布局 */
.about-container {
    max-width: 900px;
    margin: 40px auto;
    padding: 0 20px;
}

.about-block {
    background: var(--hero-bg);
    padding: 30px;
    border-radius: 10px;
    border: 1px solid #ddd;
    margin-bottom: 30px;
}

.about-block h2 {
    margin-bottom: 12px;
    font-size: 22px;
}

.about-list {
    padding-left: 20px;
    line-height: 1.8;
}

/* 团队成员列表 */
.team-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-top: 10px;
}

.team-item {
    padding: 12px 15px;
    border: 1px solid #ccc;
    border-radius: 8px;
    background: var(--bg);
}

.team-name {
    font-size: 18px;
    font-weight: 600;
}

.team-role {
    font-size: 14px;
    opacity: 0.7;
    margin-top: 4px;
}

/* 加入我们页面布局 */
.join-container {
    max-width: 900px;
    margin: 40px auto;
    padding: 0 20px;
}

.join-block {
    background: var(--hero-bg);
    padding: 30px;
    border-radius: 10px;
    border: 1px solid #ddd;
    margin-bottom: 30px;
}

.join-block h2 {
    margin-bottom: 12px;
    font-size: 22px;
}

.join-list {
    padding-left: 20px;
    line-height: 1.8;
}

.join-contact {
    font-weight: 600;
    margin-top: 10px;
    line-height: 1.8;
}