/* ==================== 全局变量 ==================== */
:root {
    --primary: #0088CC;
    --primary-dark: #0077B5;
    --primary-light: #E8F4FD;
    --text-dark: #1A1A2E;
    --text-light: #4A4A68;
    --text-gray: #8B8BA7;
    --bg-light: #F5F7FA;
    --bg-white: #FFFFFF;
    --border: rgba(0, 0, 0, 0.06);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.06);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

img {
    max-width: 100%;
    display: block;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ==================== 导航栏 ==================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 18px;
    font-weight: 700;
    color: var(--text-dark);
}

.logo:hover {
    opacity: 0.8;
}

.nav {
    display: flex;
    align-items: center;
    gap: 4px;
}

.nav a {
    padding: 8px 16px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-light);
    border-radius: var(--radius-sm);
}

.nav a:hover {
    color: var(--primary);
    background: var(--primary-light);
}

.nav a.active {
    color: var(--primary);
    background: var(--primary-light);
}

/* ==================== Hero 区域 ==================== */
.hero {
    position: relative;
    min-height: 600px;
    display: flex;
    align-items: center;
    background: var(--bg-white);
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 60% 40%, rgba(0, 136, 204, 0.05) 0%, transparent 60%);
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero-content {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
    padding: 100px 0 60px;
}

.hero-title {
    font-size: 44px;
    font-weight: 800;
    margin-bottom: 20px;
    letter-spacing: -1px;
    line-height: 1.2;
}

.hero-title .highlight {
    color: var(--primary);
}

.hero-desc {
    font-size: 17px;
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 40px;
    max-width: 560px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-bottom: 56px;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 36px;
    background: var(--primary);
    color: white;
    font-size: 16px;
    font-weight: 600;
    border-radius: var(--radius-xl);
    box-shadow: 0 4px 20px rgba(0, 136, 204, 0.3);
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(0, 136, 204, 0.4);
}

.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 64px;
    padding-top: 40px;
    border-top: 1px solid var(--border);
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 32px;
    font-weight: 800;
    color: var(--text-dark);
    line-height: 1;
    margin-bottom: 6px;
}

.stat-label {
    font-size: 13px;
    color: var(--text-gray);
}

/* ==================== 亮点区域 ==================== */
.highlights {
    padding: 80px 0;
    background: var(--bg-light);
}

.highlights-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.highlight-item {
    background: var(--bg-white);
    border-radius: var(--radius-md);
    padding: 28px 20px;
    text-align: center;
    transition: all 0.3s ease;
}

.highlight-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.highlight-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 16px;
}

.highlight-item h3 {
    font-size: 15px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.highlight-item p {
    font-size: 13px;
    color: var(--text-gray);
    line-height: 1.6;
}

/* ==================== 下载页面 Hero ==================== */
.download-hero {
    padding: 120px 0 60px;
    background: var(--bg-white);
    text-align: center;
}

.download-hero-content h1 {
    font-size: 40px;
    font-weight: 800;
    color: var(--text-dark);
    margin-bottom: 12px;
}

.download-hero-content p {
    font-size: 16px;
    color: var(--text-gray);
}

/* ==================== 下载区块 ==================== */
.download-section {
    padding: 0 0 80px;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.download-card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    text-align: center;
    transition: all 0.3s ease;
}

.download-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: transparent;
}

.download-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
}

.download-info h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 6px;
}

.download-info p {
    font-size: 13px;
    color: var(--text-gray);
    margin-bottom: 20px;
}

.download-actions {
    display: flex;
    justify-content: center;
}

.btn-download {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 24px;
    background: var(--primary);
    color: white;
    font-size: 14px;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: all 0.3s ease;
}

.btn-download:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

/* ==================== 页脚 ==================== */
.footer {
    background: #0F0F1A;
    color: white;
    padding: 56px 0 32px;
}

.footer-main {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 40px;
}

.footer-brand {
    max-width: 280px;
}

.footer-brand .logo {
    margin-bottom: 14px;
    color: white;
}

.footer-brand p {
    font-size: 13px;
    color: #8888A0;
    line-height: 1.7;
}

.footer-col h4 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
    color: white;
}

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

.footer-col li {
    margin-bottom: 10px;
}

.footer-col a {
    font-size: 13px;
    color: #8888A0;
    transition: color 0.3s ease;
}

.footer-col a:hover {
    color: var(--primary);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding-top: 24px;
    text-align: center;
}

.footer-bottom p {
    font-size: 12px;
    color: #555568;
}

/* ==================== 响应式 ==================== */
@media (max-width: 1024px) {
    .highlights-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .footer-main {
        grid-template-columns: repeat(2, 1fr);
        gap: 36px;
    }
}

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

    .hero-title {
        font-size: 30px;
    }

    .hero-desc {
        font-size: 15px;
    }

    .hero-stats {
        flex-wrap: wrap;
        gap: 24px;
    }

    .stat-item {
        flex: 1 1 40%;
    }

    .highlights-grid {
        grid-template-columns: 1fr;
    }

    .download-grid {
        grid-template-columns: 1fr;
    }

    .download-hero h1 {
        font-size: 30px;
    }

    .footer-main {
        grid-template-columns: 1fr;
        gap: 28px;
    }

    .footer-brand {
        max-width: none;
    }
}

/* ==================== 滚动条 ==================== */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: var(--primary);
    border-radius: 3px;
}