/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 全局样式 */
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;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

/* 头部样式 */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.subtitle {
    font-size: 1rem;
    opacity: 0.9;
}

/* 主内容区域 */
main {
    padding: 40px;
}

/* 区域标题 */
h2 {
    font-size: 1.5rem;
    color: #667eea;
    margin-bottom: 25px;
    padding-bottom: 10px;
    border-bottom: 3px solid #667eea;
}

/* 输入区域样式 */
.input-section {
    margin-bottom: 50px;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-weight: 600;
    margin-bottom: 8px;
    color: #555;
    font-size: 0.95rem;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.form-group input {
    width: 100%;
    padding: 12px 50px 12px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background: #f9f9f9;
}

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

.form-group input:hover {
    border-color: #667eea;
}

.unit {
    position: absolute;
    right: 15px;
    color: #999;
    font-size: 0.9rem;
}

.form-group small {
    margin-top: 5px;
    color: #888;
    font-size: 0.85rem;
}

/* 按钮组样式 */
.button-group {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-top: 20px;
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

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

.btn-secondary {
    background: #f0f0f0;
    color: #666;
}

.btn-secondary:hover {
    background: #e0e0e0;
    transform: translateY(-2px);
}

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

/* 结果区域样式 */
.result-section {
    background: #f9f9f9;
    padding: 30px;
    border-radius: 12px;
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}

.result-item {
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.result-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.result-item label {
    display: block;
    font-weight: 600;
    color: #555;
    margin-bottom: 10px;
    font-size: 0.9rem;
}

.result-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: #333;
    word-break: break-all;
}

.result-value.highlight {
    color: #667eea;
}

.result-value.total {
    color: #764ba2;
    font-size: 2.2rem;
}

.total-tax {
    grid-column: 1 / -1;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 25px;
    border-radius: 12px;
}

.total-tax label {
    color: white;
    font-size: 1.1rem;
}

.total-tax .result-value {
    color: white;
    font-size: 2.5rem;
}

/* 页脚样式 */
footer {
    background: #f5f5f5;
    padding: 20px;
    text-align: center;
    color: #888;
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    header {
        padding: 30px 20px;
    }

    header h1 {
        font-size: 1.8rem;
    }

    main {
        padding: 20px;
    }

    .form-grid {
        grid-template-columns: 1fr;
    }

    .result-grid {
        grid-template-columns: 1fr;
    }

    .button-group {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .result-value {
        font-size: 1.5rem;
    }

    .result-value.total {
        font-size: 2rem;
    }

    .total-tax .result-value {
        font-size: 2.2rem;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.5rem;
    }

    .subtitle {
        font-size: 0.85rem;
    }

    h2 {
        font-size: 1.2rem;
    }

    .result-value {
        font-size: 1.3rem;
    }

    .result-value.total {
        font-size: 1.8rem;
    }

    .total-tax .result-value {
        font-size: 2rem;
    }
}

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

.result-item {
    animation: fadeIn 0.5s ease-out;
}

.result-item:nth-child(1) { animation-delay: 0.1s; }
.result-item:nth-child(2) { animation-delay: 0.2s; }
.result-item:nth-child(3) { animation-delay: 0.3s; }
.result-item:nth-child(4) { animation-delay: 0.4s; }
.result-item:nth-child(5) { animation-delay: 0.5s; }
.result-item:nth-child(6) { animation-delay: 0.6s; }
.result-item:nth-child(7) { animation-delay: 0.7s; }
.result-item:nth-child(8) { animation-delay: 0.8s; }
.result-item:nth-child(9) { animation-delay: 0.9s; }