/* 深色主题风格CSS - 快连VPN深色版 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #7c3aed;
    --primary-dark: #6d28d9;
    --primary-light: #8b5cf6;
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --bg-hover: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    --gradient: linear-gradient(135deg, #7c3aed 0%, #4f46e5 100%);
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-dark);
    overflow-x: hidden;
}

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

/* 导航栏 */
.navbar {
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo {
    font-size: 1.5rem;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.brand-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
    font-weight: 500;
}

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

/* 头部区域 */
.header {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 20% 80%, rgba(124, 58, 237, 0.1) 0%, transparent 50%);
}

.header-content {
    max-width: 600px;
    z-index: 2;
    position: relative;
}

.site-title {
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, #f1f5f9 0%, #cbd5e1 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.slogan {
    font-size: 1.5rem;
    color: var(--primary-light);
    margin-bottom: 1rem;
    font-weight: 600;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.6;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: var(--gradient);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(124, 58, 237, 0.3);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-hover);
    border-color: var(--primary-light);
}

/* 设备预览 */
.dark-theme-preview {
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 300px;
}

.device-mockup {
    background: var(--bg-card);
    border-radius: 20px;
    padding: 20px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.screen {
    background: #0f172a;
    border-radius: 10px;
    padding: 15px;
    min-height: 200px;
}

.app-interface {
    color: var(--text-primary);
}

.status-bar {
    height: 2px;
    background: var(--gradient);
    margin-bottom: 15px;
    border-radius: 1px;
}

.connection-status {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
}

.status-indicator {
    width: 8px;
    height: 8px;
    background: #10b981;
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.server-info {
    display: flex;
    justify-content: space-between;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* 功能区域 */
.features {
    padding: 80px 0;
    background: var(--bg-dark);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.feature-item {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    text-align: center;
}

.feature-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
    border-color: var(--primary-light);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature-content h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.feature-content p {
    color: var(--text-secondary);
    line-height: 1.5;
}

/* 优势区域 */
.advantages {
    padding: 80px 0;
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
    background: linear-gradient(135deg, #f1f5f9 0%, #cbd5e1 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.advantage-item {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.advantage-item h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--primary-light);
}

.advantage-item p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 下载区域 */
.download {
    padding: 80px 0;
    background: var(--bg-dark);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.download-item {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    text-align: center;
    transition: all 0.3s ease;
}

.download-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
    border-color: var(--primary-light);
}

.platform-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.download-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.download-item p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.btn-download {
    background: var(--gradient);
    color: white;
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-download:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(124, 58, 237, 0.3);
}

/* 页脚 */
.footer {
    background: var(--bg-card);
    padding: 3rem 0 1rem;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    text-align: center;
    margin-bottom: 2rem;
}

.footer-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.footer-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-copyright {
    text-align: center;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .site-title {
        font-size: 2rem;
    }
    
    .slogan {
        font-size: 1.25rem;
    }
    
    .dark-theme-preview {
        position: relative;
        width: 100%;
        margin-top: 2rem;
    }
    
    .cta-buttons {
        justify-content: center;
    }
    
    .features-grid,
    .advantages-grid,
    .download-grid {
        grid-template-columns: 1fr;
    }
}

/* 无障碍支持 */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}