* {
    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;
    color: #333;
}

.container {
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    padding: 2rem;
    text-align: center;
    width: 90%;
    max-width: 500px;
}

h1 {
    margin-bottom: 1.5rem;
    color: #4a4a8c;
    font-size: 2rem;
}

.timer-display {
    margin-bottom: 2rem;
}

#timer {
    font-size: 4rem;
    font-weight: bold;
    color: #4a4a8c;
    margin-bottom: 0.5rem;
    font-family: 'Courier New', monospace;
}

#mode {
    font-size: 1.2rem;
    color: #666;
}

.progress-container {
    width: 100%;
    height: 20px;
    background-color: #e0e0e0;
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 2rem;
}

.progress-bar {
    width: 100%;
    height: 100%;
    background-color: #f0f0f0;
    border-radius: 10px;
}

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

.controls {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.btn {
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

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

#start-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
}

#pause-btn {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    color: white;
}

#pause-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
}

#reset-btn {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
}

#reset-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.2);
}

.stats {
    font-size: 1.2rem;
    color: #4a4a8c;
    font-weight: bold;
}

.stats span {
    font-size: 1.5rem;
    color: #667eea;
}

/* 响应式设计 */
@media (max-width: 600px) {
    .container {
        padding: 1.5rem;
        width: 95%;
    }
    
    h1 {
        font-size: 1.5rem;
    }
    
    #timer {
        font-size: 3rem;
    }
    
    .controls {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 80%;
    }
}