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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

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

header {
    text-align: center;
    margin-bottom: 40px;
    color: white;
}

header h1 {
    font-size: 3rem;
    margin-bottom: 10px;
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

header p {
    font-size: 1.2rem;
    opacity: 0.9;
    font-weight: 300;
}

.clock-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    padding: 20px 0;
}

.clock-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 30px 25px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    overflow: hidden;
}

.clock-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
}

.clock-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #667eea, #764ba2);
}

.city-name {
    font-size: 1.4rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 8px;
    text-align: center;
}

.country {
    font-size: 1rem;
    color: #666;
    text-align: center;
    margin-bottom: 20px;
    font-weight: 300;
}

.time-display {
    text-align: center;
    margin-bottom: 15px;
}

.time {
    font-size: 2.5rem;
    font-weight: 700;
    color: #2c3e50;
    font-family: 'Courier New', monospace;
    margin-bottom: 5px;
    letter-spacing: 1px;
}

.date {
    font-size: 1rem;
    color: #7f8c8d;
    font-weight: 400;
}

.timezone-info {
    background: rgba(103, 126, 234, 0.1);
    border-radius: 10px;
    padding: 10px;
    text-align: center;
    font-size: 0.9rem;
    color: #5a6c7d;
    font-weight: 500;
}

.flag {
    font-size: 1.5rem;
    margin-right: 8px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2.5rem;
    }
    
    header p {
        font-size: 1rem;
    }
    
    .clock-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .clock-card {
        padding: 25px 20px;
    }
    
    .time {
        font-size: 2.2rem;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 2rem;
    }
    
    .time {
        font-size: 2rem;
    }
    
    .city-name {
        font-size: 1.2rem;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.clock-card {
    animation: fadeIn 0.6s ease-out;
}

/* 时间闪烁效果 */
.time.updating {
    animation: pulse 0.5s ease-in-out;
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.02); }
    100% { transform: scale(1); }
}