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

/* 全屏背景图容器 - 默认渐变色占位，图片加载后覆盖 */
.bg-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    transition: opacity 0.8s ease;
    opacity: 0;
    will-change: opacity;
}

.bg-container.loaded {
    opacity: 1;
}

/* 背景暗色遮罩，让内容更清晰 */
.bg-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: rgba(0, 0, 0, 0.5);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 16px;
}

.container {
    width: 100%;
    max-width: 900px;
}

.header {
    text-align: center;
    margin-bottom: 30px;
    color: white;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 8px;
}

.logo-icon {
    width: 32px;
    height: 32px;
}

.logo h1 {
    font-size: 26px;
    font-weight: 700;
}

.subtitle {
    font-size: 14px;
    opacity: 0.9;
}

.main {
    background: white;
    border-radius: 16px;
    padding: 28px;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.12);
}

.mail-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 16px;
    margin-bottom: 28px;
}

.mail-card {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px;
    border-radius: 14px;
    text-decoration: none;
    color: white;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.mail-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.1);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.mail-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
}

.mail-card:hover::before {
    opacity: 1;
}

.mail-card-1 {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.mail-card-2 {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
}

.card-icon {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.card-icon svg {
    width: 22px;
    height: 22px;
}

.card-content {
    flex: 1;
}

.card-content h2 {
    font-size: 17px;
    font-weight: 600;
    margin-bottom: 2px;
}

.card-content p {
    font-size: 12px;
    opacity: 0.9;
    margin-bottom: 8px;
}

.card-btn {
    font-size: 12px;
    font-weight: 500;
    display: inline-block;
    padding: 4px 12px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 20px;
    transition: background 0.3s ease;
}

.mail-card:hover .card-btn {
    background: rgba(255, 255, 255, 0.3);
}

.info-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 14px;
    content-visibility: auto;
    contain-intrinsic-size: 200px;
}

.info-card {
    background: #f8fafc;
    border-radius: 10px;
    padding: 18px;
    border: 1px solid #e2e8f0;
}

.info-card h3 {
    font-size: 14px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 8px;
}

.info-card ul {
    list-style: none;
}

.info-card li {
    font-size: 13px;
    color: #64748b;
    padding: 4px 0;
    padding-left: 18px;
    position: relative;
}

.info-card li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: #667eea;
    font-weight: bold;
}

.footer {
    text-align: center;
    margin-top: 20px;
    color: rgba(255, 255, 255, 0.8);
    font-size: 12px;
}

@media (max-width: 640px) {
    .header {
        margin-bottom: 20px;
    }
    
    .logo h1 {
        font-size: 20px;
    }
    
    .subtitle {
        font-size: 12px;
    }
    
    .main {
        padding: 18px;
        border-radius: 12px;
    }
    
    .mail-cards {
        gap: 12px;
        margin-bottom: 20px;
    }
    
    .mail-card {
        padding: 16px;
        gap: 12px;
    }
    
    .card-icon {
        width: 40px;
        height: 40px;
    }
    
    .card-icon svg {
        width: 20px;
        height: 20px;
    }
    
    .card-content h2 {
        font-size: 15px;
    }
    
    .card-content p {
        font-size: 11px;
    }
    
    .info-section {
        gap: 12px;
    }
    
    .info-card {
        padding: 14px;
    }
}