/* ========== 基础变量与重置 ========== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary-deep: #1a365d;
    --primary: #2b6cb0;
    --primary-light: #2a4365;
    --text-dark: #2c3e50;
    --text-gray: #4a5568;
    --text-light: #718096;
    --border-light: #e2e8f0;
    --bg-page: #f4f7fa;
    --bg-white: #ffffff;
    --bg-dark-footer: #1a202c;
    --footer-text: #a0aec0;
    --shadow-sm: 0 4px 6px rgba(0,0,0,0.02);
    --shadow-card: 0 10px 25px -5px rgba(0,0,0,0.03);
    --radius: 8px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    background: var(--bg-page);
    color: var(--text-dark);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ========== 导航栏（与首页完全一致） ========== */
header {
    background: var(--bg-white);
    box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    padding: 15px 0;
}

.logo-area {
    flex-shrink: 0;
}

.logo-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--primary-deep);
    font-size: 22px;
    font-weight: 700;
    gap: 10px;
    white-space: nowrap;
}

.logo-link img {
    vertical-align: middle;
}

.menu-area {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
}

.menu-area a {
    color: var(--text-gray);
    text-decoration: none;
    font-weight: 500;
    font-size: 15px;
    padding: 5px 0;
    border-bottom: 2px solid transparent;
    transition: color 0.2s, border-color 0.2s;
}

.menu-area a:hover,
.menu-area a.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

/* ========== 页面Hero区 ========== */
.page-hero {
    background: linear-gradient(135deg, #1a365d 0%, #2a4365 100%);
    color: #fff;
    padding: 60px 0;
    text-align: center;
}

.page-hero h1 {
    font-size: 32px;
    font-weight: 700;
    letter-spacing: -0.5px;
    margin-bottom: 15px;
    line-height: 1.3;
}

.hero-sub {
    font-size: 18px;
    max-width: 700px;
    margin: 0 auto 30px auto;
    color: #e2e8f0;
    opacity: 0.95;
}

/* Hero按钮组 */
.hero-actions {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 18px;
    margin-bottom: 30px;
}

.btn-primary,
.btn-outline {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    font-size: 16px;
    font-weight: 600;
    border-radius: 50px;
    text-decoration: none;
    transition: all 0.25s ease;
    border: 2px solid transparent;
    line-height: 1.2;
}

.btn-primary {
    background: #ffffff;
    color: var(--primary-deep);
    border-color: #ffffff;
    box-shadow: 0 8px 18px rgba(0,0,0,0.1);
}

.btn-primary:hover {
    background: #edf2f7;
    border-color: #edf2f7;
    transform: translateY(-2px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.15);
}

.btn-outline {
    background: transparent;
    color: #ffffff;
    border-color: rgba(255,255,255,0.7);
}

.btn-outline:hover {
    background: rgba(255,255,255,0.15);
    border-color: #ffffff;
    transform: translateY(-2px);
}

/* ========== 主内容区 ========== */
main {
    padding: 50px 0;
}

.trust-badge {
    background: #f0f9ff;
    border: 1px solid #bee3f8;
    border-radius: var(--radius);
    padding: 20px 25px;
    margin-bottom: 40px;
    color: #2b6cb0;
    font-size: 15px;
}

/* 快速上手三步条 */
.quick-start-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    background: var(--bg-white);
    padding: 25px 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    margin-bottom: 45px;
    justify-content: center;
}

.quick-item {
    display: flex;
    align-items: center;
    gap: 12px;
    flex: 1 1 180px;
    min-width: 180px;
}

.quick-icon {
    display: inline-flex;
    width: 40px;
    height: 40px;
    background: var(--primary);
    color: #fff;
    border-radius: 50%;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 18px;
    flex-shrink: 0;
}

/* 下载卡片网格 */
.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
    margin-bottom: 50px;
}

.download-card {
    background: var(--bg-white);
    border-radius: var(--radius);
    padding: 30px 25px;
    box-shadow: var(--shadow-card);
    text-align: center;
    transition: all 0.25s ease;
    border: 1px solid var(--border-light);
    display: flex;
    flex-direction: column;
}

.download-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 35px -8px rgba(43, 108, 176, 0.08);
    border-color: var(--primary);
}

.os-icon {
    margin-bottom: 15px;
}

.download-card h2 {
    font-size: 20px;
    color: var(--primary-deep);
    margin: 0 0 10px 0;
}

.version-tag {
    display: inline-block;
    background: #ebf8ff;
    color: var(--primary);
    font-size: 12px;
    padding: 3px 12px;
    border-radius: 20px;
    margin-bottom: 15px;
    font-weight: 600;
}

.download-card p {
    font-size: 14px;
    color: var(--text-gray);
    margin-bottom: 20px;
    flex-grow: 1;
}

.btn-download {
    display: block;
    width: 100%;
    padding: 12px 0;
    color: #fff;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    font-size: 15px;
    transition: background 0.2s, transform 0.1s;
    margin-top: auto;
}

.btn-download:active {
    transform: scale(0.98);
}

.btn-win { background: #3182ce; }
.btn-win:hover { background: #2b6cb0; }
.btn-mac { background: #4a5568; }
.btn-mac:hover { background: #2d3748; }
.btn-ios { background: #2f855a; }
.btn-ios:hover { background: #22543d; }
.btn-and { background: #805ad5; }
.btn-and:hover { background: #6b46c1; }

/* 通用附加版块 */
.extra-section {
    background: var(--bg-white);
    padding: 35px 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    margin-bottom: 40px;
}

.extra-section h2 {
    color: var(--primary-deep);
    font-size: 24px;
    margin: 0 0 25px 0;
    padding-left: 12px;
    border-left: 4px solid var(--primary);
}

/* 视频容器 */
.video-container {
    max-width: 750px;
    margin: 0 auto;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: 0 15px 30px rgba(0,0,0,0.05);
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    background: #000;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

/* 为什么选择我们 网格 */
.why-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 25px;
}

.why-item {
    text-align: center;
    padding: 20px 15px;
}

.why-icon {
    font-size: 36px;
    margin-bottom: 15px;
    display: block;
}

.why-item h3 {
    font-size: 18px;
    color: var(--primary-deep);
    margin-bottom: 10px;
}

.why-item p {
    font-size: 14px;
    color: var(--text-gray);
}

/* 历史版本表格 */
.history-table-wrapper {
    overflow-x: auto;
}

.history-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14px;
    white-space: nowrap;
}

.history-table th {
    text-align: left;
    padding: 12px 15px;
    background: #f7fafc;
    color: var(--text-gray);
    font-weight: 600;
    border-bottom: 2px solid var(--border-light);
}

.history-table td {
    padding: 12px 15px;
    border-bottom: 1px solid var(--border-light);
    color: var(--text-dark);
}

.history-table tbody tr:hover {
    background: #f7fafc;
}

/* ========== 页脚（与首页完全一致） ========== */
footer {
    background: var(--bg-dark-footer);
    color: var(--footer-text);
    padding: 50px 0 0;
    border-top: 4px solid var(--primary);
    font-size: 14px;
}

.footer-table {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 30px;
    padding-bottom: 30px;
}

.footer-row {
    display: flex;
    flex-wrap: wrap;
    width: 100%;
    gap: 30px;
}

.footer-cell {
    flex: 1 1 200px;
    min-width: 160px;
}

.footer-cell h4 {
    color: #fff;
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 20px;
    letter-spacing: 0.3px;
}

.footer-cell ul {
    list-style: none;
}

.footer-cell ul li {
    margin-bottom: 12px;
}

.footer-cell ul li a {
    color: var(--footer-text);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-cell ul li a:hover {
    color: #fff;
}

.footer-bottom {
    border-top: 1px solid #2d3748;
    padding: 20px 0;
    text-align: center;
    font-size: 13px;
    color: var(--footer-text);
    line-height: 1.8;
}

/* ========== 响应式设计 ========== */
@media (max-width: 768px) {
    .nav-wrapper {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }
    .menu-area {
        justify-content: center;
    }
    .page-hero h1 {
        font-size: 26px;
    }
    .hero-sub {
        font-size: 16px;
    }
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    .btn-primary,
    .btn-outline {
        width: 80%;
        justify-content: center;
    }
    .quick-start-bar {
        flex-direction: column;
        gap: 15px;
    }
    .quick-item {
        justify-content: center;
    }
    .download-grid {
        grid-template-columns: 1fr;
    }
    .why-grid {
        grid-template-columns: 1fr;
    }
    .extra-section {
        padding: 25px 20px;
    }
    .footer-row {
        flex-direction: column;
    }
}