* {
    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;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    width: 100%;
    max-width: 900px;
    overflow: hidden;
    padding: 30px;
}

header {
    text-align: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 2px solid #f0f0f0;
}

header h1 {
    color: #333;
    font-size: 2.5rem;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
}

header h1 i {
    color: #667eea;
}

.subtitle {
    color: #666;
    font-size: 1.1rem;
}

.control-panel {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 30px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 600;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.input-group input {
    width: 100%;
    padding: 15px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.input-group input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.button-group {
    display: flex;
    gap: 15px;
    margin-top: 25px;
}

.btn {
    flex: 1;
    padding: 18px;
    border: none;
    border-radius: 10px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.start-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.start-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

.reset-btn {
    background: #f8f9fa;
    color: #666;
    border: 2px solid #e0e0e0;
}

.reset-btn:hover {
    background: #e9ecef;
    transform: translateY(-2px);
}

.countdown-display {
    background: white;
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    text-align: center;
}

.event-info {
    margin-bottom: 30px;
}

.event-info h2 {
    color: #333;
    font-size: 1.8rem;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.event-info p {
    color: #666;
    font-size: 1.1rem;
}

.countdown-timer {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    margin: 40px 0;
    flex-wrap: wrap;
}

.time-unit {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 15px;
    padding: 25px 15px;
    min-width: 120px;
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.2);
}

.time-value {
    font-size: 3.5rem;
    font-weight: 700;
    color: white;
    line-height: 1;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.time-label {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.1rem;
    margin-top: 10px;
    font-weight: 500;
}

.separator {
    font-size: 3rem;
    color: #667eea;
    font-weight: 700;
    margin: 0 5px;
}

.progress-container {
    background: #f0f0f0;
    border-radius: 10px;
    height: 12px;
    margin: 40px 0;
    overflow: hidden;
}

.progress-bar {
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
    height: 100%;
    width: 0%;
    border-radius: 10px;
    transition: width 1s ease;
}

.status-message {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 20px;
    color: #666;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.presets {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 30px;
}

.presets h3 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.4rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.preset-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
}

.preset-btn {
    padding: 15px;
    background: white;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    color: #555;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.preset-btn:hover {
    background: #667eea;
    color: white;
    border-color: #667eea;
    transform: translateY(-2px);
}

footer {
    text-align: center;
    color: #666;
    padding-top: 20px;
    border-top: 2px solid #f0f0f0;
}

footer p {
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.app-status {
    color: #28a745;
    font-weight: 600;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 20px;
    }
    
    header h1 {
        font-size: 2rem;
        flex-direction: column;
        gap: 10px;
    }
    
    .countdown-timer {
        gap: 10px;
    }
    
    .time-unit {
        min-width: 80px;
        padding: 15px 10px;
    }
    
    .time-value {
        font-size: 2.5rem;
    }
    
    .separator {
        font-size: 2rem;
    }
    
    .button-group {
        flex-direction: column;
    }
    
    .preset-buttons {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .time-unit {
        min-width: 70px;
        padding: 12px 8px;
    }
    
    .time-value {
        font-size: 2rem;
    }
    
    .time-label {
        font-size: 0.9rem;
    }
    
    .separator {
        font-size: 1.5rem;
    }
}

/* 动画效果 */
@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.pulse {
    animation: pulse 1s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fadeIn 0.5s ease-out;
}