/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 全局样式 */
body {
    font-family: "Microsoft Yahei", sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: #333;
    text-align: center; /* 全局文字居中 */
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

/* 段落左对齐 */
p {
    text-align: left;
}

/* 标题层级 */
h1 {
    font-size: 28px;
    line-height: 1.3;
}

h2 {
    font-size: 24px;
    line-height: 1.4;
}

h3 {
    font-size: 20px;
    line-height: 1.5;
}

h4 {
    font-size: 18px;
    line-height: 1.5;
}

/* 页头样式 */
.header {
    background: linear-gradient(to right, #f8f9fa, #e9ecef);
    padding: 15px 0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    position: relative;
    z-index: 100;
}

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

.logo {
    color: #2c3e50;
    font-weight: 700;
}

/* 桌面端导航 */
.nav-desktop ul {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-desktop a {
    color: #2c3e50;
    text-decoration: none;
    font-size: 16px;
    transition: color 0.3s ease;
}

.nav-desktop a:hover {
    color: #3498db;
}

/* 移动端汉堡按钮 */
.hamburger-btn {
    display: none;
    cursor: pointer;
}

.hamburger-btn img {
    width: 30px;
    height: 30px;
}

/* 移动端导航 */
.nav-mobile {
    position: fixed;
    top: 0;
    right: 0;
    width: 260px;
    height: 100vh;
    background: #fff;
    box-shadow: -2px 0 10px rgba(0,0,0,0.15);
    transform: translateX(100%);
    transition: transform 0.3s ease;
    z-index: 101;
    padding-top: 80px;
}

.nav-mobile.active {
    transform: translateX(0);
}

.nav-mobile ul {
    list-style: none;
    padding: 0 20px;
}

.nav-mobile li {
    margin: 15px 0;
    background: #f5f5f5; /* 移动端菜单背景色区分 */
    padding: 10px 15px;
    border-radius: 6px;
}

.nav-mobile a {
    color: #2c3e50;
    text-decoration: none;
    font-size: 16px;
    display: block;
}

.close-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    cursor: pointer;
}

.close-btn img {
    width: 30px;
    height: 30px;
}

/* 横幅样式 */
.hero {
    padding: 60px 0;
    background: #fafafa;
}

.hero-inner {
    display: flex;
    align-items: center;
    gap: 40px;
}

.hero-text {
    flex: 1;
}

.hero-title {
    color: #2c3e50;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 15px;
}

.hero-title::after {
    content: "";
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    bottom: 0;
    width: 80px;
    height: 3px;
    background: #3498db;
}

.hero-desc {
    margin-bottom: 30px;
    color: #666;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.download-btn {
    display: inline-block;
    padding: 12px 30px;
    background: linear-gradient(to right, #3498db, #2980b9);
    color: #fff;
    text-decoration: none;
    border-radius: 30px;
    font-weight: 600;
    box-shadow: 0 4px 12px rgba(52, 152, 219, 0.3);
    transition: all 0.3s ease;
}

.download-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(52, 152, 219, 0.4);
}

.hero-img {
    flex: 1;
}

.hero-img img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
}

/* 团队介绍区块 */
.team-intro {
    padding: 70px 0;
    background: #fff;
}

.section-title {
    color: #2c3e50;
    margin-bottom: 10px;
}

.section-subtitle {
    color: #777;
    margin-bottom: 40px;
    font-size: 18px;
}

.team-cards {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.team-card {
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.team-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.12);
}

.team-card img {
    width: 100%;
    height: 370px;
    object-fit: cover;
}

.card-content {
    padding: 20px;
}

.card-content h3 {
    color: #2c3e50;
    margin-bottom: 15px;
}

.card-content p {
    color: #666;
    font-size: 15px;
}

/* 下载区块 */
.download-section {
    padding: 70px 0;
    background: #f8f9fa;
}

.download-inner {
    display: flex;
    align-items: center;
    gap: 40px;
}

.download-text {
    flex: 1;
}

.download-title {
    color: #2c3e50;
    margin-bottom: 20px;
}

.download-desc {
    color: #666;
    margin-bottom: 30px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.download-btns {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
}

.btn {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 25px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 3px 10px rgba(0,0,0,0.08);
}

.btn img {
    width: 60px;
    height: 60px;
}

.apple-btn {
    background: #f5f5f7;
    color: #1d1d1f;
}

.android-btn {
    background: #e6f4ea;
    color: #34a853;
}

.reg-btn {
    background: #fff0f5;
    color: #e53e3e;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.12);
}

.download-img {
    flex: 1;
}

.download-img img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
}

/* 折叠内容区块 */
.collapse-section {
    padding: 70px 0;
    background: #fff;
}

.collapse-items {
    max-width: 800px;
    margin: 0 auto;
}

.collapse-item {
    margin-bottom: 15px;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    overflow: hidden;
}

.collapse-header {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 15px 20px;
    background: #f5f5f5;
    cursor: pointer;
    justify-content: center;
}

.collapse-icon {
    width: 20px;
    height: 20px;
    transition: transform 0.3s ease;
}

.collapse-header.active .collapse-icon {
    transform: rotate(90deg);
}

.collapse-content {
    padding: 20px;
    background: #fff;
    display: none;
}

.collapse-content p {
    color: #666;
}

/* 关注我们 & APP下载区块 */
.follow-download {
    padding: 60px 0;
    background: #fafafa;
}

.follow-download-inner {
    display: flex;
    justify-content: center;
    gap: 80px;
    align-items: center;
}

.follow-us h3, .app-download h3 {
    color: #2c3e50;
    margin-bottom: 20px;
}

.qrcode {
    width: 180px;
    height: 180px;
    border: 5px solid #fff;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    margin-bottom: 15px;
}

.follow-us p {
    color: #777;
    text-align: center;
}

.app-btns {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.app-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 30px;
    background: #3498db; /* 按钮背景色 */
    color: #fff;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.app-btn img {
    width: 32px;
    height: 38px;
}

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

/* 页尾样式 - 核心调整：确保PC/移动端对齐，移动端一行两个 */
.footer {
    background: #2c3e50;
    color: #fff;
    padding: 60px 0 30px;
}

.footer-top {
    display: grid;
    /* PC端4列，强制对齐 */
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 40px;
    /* 确保列宽一致，对齐 */
    justify-items: flex-start;
}

/* 页尾列容器：统一左对齐，确保h4和列表对齐 */
.footer-col {
    width: 100%;
    text-align: left !important;
    padding: 0 10px;
}

/* 页尾标题：强制左对齐，统一间距 */
.footer-col h4 {
    color: #fff;
    margin-bottom: 15px;
    padding-bottom: 8px;
    border-bottom: 2px solid #3498db;
    display: block; /* 取消inline-block，确保宽度对齐 */
    text-align: left !important;
}

/* 页尾列表：强制左对齐，统一样式 */
.footer-col ul {
    list-style: none;
    text-align: left !important;
    padding-left: 0; /* 重置内边距，确保对齐 */
}

.footer-col li {
    margin: 8px 0;
}

.footer-col a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s ease;
    display: block; /* 确保点击区域对齐 */
}

.footer-col a:hover {
    color: #3498db;
}

.footer-middle {
    border-top: 1px solid #34495e;
    border-bottom: 1px solid #34495e;
    padding: 20px 0;
    margin-bottom: 30px;
}

.footer-middle ul {
    display: flex;
    justify-content: center;
    list-style: none;
    gap: 30px;
    flex-wrap: wrap;
}

.footer-middle a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-middle a:hover {
    color: #3498db;
}

.footer-bottom {
    color: #95a5a6;
    font-size: 14px;
}

/* 响应式适配 - 核心调整 */
@media (max-width: 992px) {
    /* 移动端（平板/手机）页尾一行两个 */
    .footer-top {
        grid-template-columns: repeat(2, 1fr);
        justify-items: flex-start; /* 保持左对齐 */
    }

    .hero-inner {
        flex-direction: column;
        text-align: center;
    }

    .team-cards {
        grid-template-columns: repeat(2, 1fr);
    }

    .download-inner {
        flex-direction: column;
    }

    .follow-download-inner {
        flex-direction: column;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .nav-desktop {
        display: none;
    }

    .hamburger-btn {
        display: block;
    }

    h1 {
        font-size: 24px;
    }

    h2 {
        font-size: 20px;
    }

    .hero {
        padding: 40px 0;
    }

    .team-intro, .download-section, .collapse-section {
        padding: 50px 0;
    }

    /* 保持移动端页尾一行两个，增强适配 */
    .footer-top {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
    }

    .footer-middle ul {
        gap: 15px;
    }
}

@media (max-width: 576px) {
    .team-cards {
        grid-template-columns: 1fr;
    }

    .download-btns {
        flex-direction: column;
        align-items: center;
    }

    /* 小屏手机仍保持一行两个，确保显示效果 */
    .footer-top {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    /* 小屏适配页尾文字大小 */
    .footer-col h4 {
        font-size: 16px;
    }

    .footer-col a {
        font-size: 14px;
    }
}