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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

h1 {
    text-align: center;
    color: white;
    margin-bottom: 30px;
    font-size: 28px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

.calculator {
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    margin-bottom: 30px;
}

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

.input-group label {
    display: block;
    margin-bottom: 8px;
    color: #333;
    font-weight: 500;
    font-size: 14px;
}

.input-group input,
.input-group select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 16px;
    transition: all 0.3s;
    outline: none;
}

.input-group input:focus,
.input-group select:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.calculate-btn {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    margin-top: 10px;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

.calculate-btn:active {
    transform: translateY(0);
}

.result {
    margin-top: 30px;
    padding-top: 30px;
    border-top: 2px solid #f0f0f0;
}

.result h2 {
    color: #333;
    margin-bottom: 20px;
    font-size: 20px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    padding: 12px 0;
    font-size: 16px;
    color: #666;
}

.result-item.total {
    margin-top: 15px;
    padding-top: 15px;
    border-top: 2px solid #f0f0f0;
    font-size: 20px;
    font-weight: 600;
    color: #667eea;
}

.info {
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
}

.info h3 {
    color: #333;
    margin-bottom: 20px;
    font-size: 20px;
}

.info-section {
    margin-bottom: 20px;
}

.info-section h4 {
    color: #667eea;
    margin-bottom: 10px;
    font-size: 16px;
}

.info-section ul {
    list-style: none;
    padding-left: 0;
}

.info-section li {
    padding: 6px 0;
    color: #666;
    font-size: 14px;
    line-height: 1.6;
}

.info-section li:before {
    content: "• ";
    color: #667eea;
    font-weight: bold;
    margin-right: 8px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    body {
        padding: 15px;
    }

    h1 {
        font-size: 22px;
        margin-bottom: 20px;
    }

    .calculator,
    .info {
        padding: 20px;
        border-radius: 15px;
    }

    .result h2,
    .info h3 {
        font-size: 18px;
    }

    .result-item {
        font-size: 14px;
    }

    .result-item.total {
        font-size: 18px;
    }

    .calculate-btn {
        font-size: 16px;
        padding: 12px;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 20px;
    }

    .calculator,
    .info {
        padding: 15px;
    }

    .input-group input,
    .input-group select {
        padding: 10px 12px;
        font-size: 14px;
    }
}