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

body {
    font-family: 'Microsoft YaHei', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    overflow: hidden;
}

.header {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
    text-align: center;
    padding: 40px 20px;
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.header p {
    font-size: 1.2em;
    opacity: 0.9;
}

.tools-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    padding: 40px;
}

.tool-card {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.15);
}

.tool-card h3 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.5em;
    text-align: center;
    padding-bottom: 10px;
    border-bottom: 3px solid #4facfe;
}

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

.input-group label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: bold;
}

.input-group input, .input-group textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

.input-group input:focus, .input-group textarea:focus {
    outline: none;
    border-color: #4facfe;
    box-shadow: 0 0 0 3px rgba(79, 172, 254, 0.1);
}

/* 单位选择器样式 */
.unit-selector {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 20px;
}

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

.unit-group label {
    margin-bottom: 8px;
    color: #555;
    font-weight: bold;
    font-size: 14px;
}

.unit-group select {
    padding: 10px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 14px;
    background: white;
    transition: border-color 0.3s ease;
}

.unit-group select:focus {
    outline: none;
    border-color: #4facfe;
    box-shadow: 0 0 0 3px rgba(79, 172, 254, 0.1);
}

/* 计算区域样式 */
.calc-section {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 20px;
    border: 1px solid #e9ecef;
}

.calc-section h4 {
    color: #495057;
    margin-bottom: 15px;
    font-size: 1.1em;
    text-align: center;
    padding-bottom: 8px;
    border-bottom: 2px solid #dee2e6;
}

.calc-section:last-of-type {
    margin-bottom: 0;
}

.btn {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 25px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
    font-weight: bold;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(79, 172, 254, 0.3);
}

.result {
    margin-top: 20px;
    padding: 15px;
    background: #e8f5e8;
    border-radius: 8px;
    border-left: 4px solid #28a745;
    min-height: 50px;
}

.result h4 {
    color: #28a745;
    margin-bottom: 10px;
}

.result p {
    color: #333;
    line-height: 1.6;
}

/* 结果操作按钮区域 */
.result-actions {
    margin-top: 15px;
    padding-top: 15px;
    border-top: 1px solid #d4edda;
}

/* 复制按钮样式 */
.btn-copy {
    background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
    color: white;
    border: none;
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.btn-copy:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 15px rgba(40, 167, 69, 0.3);
    background: linear-gradient(135deg, #218838 0%, #1ea085 100%);
}

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

/* 复制成功提示 */
.copy-success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 12px;
    margin-top: 10px;
    display: none;
    animation: fadeInOut 2s ease-in-out;
}

@keyframes fadeInOut {
    0% { opacity: 0; transform: translateY(-10px); }
    20% { opacity: 1; transform: translateY(0); }
    80% { opacity: 1; transform: translateY(0); }
    100% { opacity: 0; transform: translateY(-10px); }
}

.footer {
    text-align: center;
    padding: 20px;
    background: #f8f9fa;
    color: #666;
    border-top: 1px solid #e1e5e9;
}

@media (max-width: 768px) {
    .tools-container {
        grid-template-columns: 1fr;
        padding: 20px;
    }
    
    .header h1 {
        font-size: 2em;
    }
}