* {
    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: 15px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    overflow: hidden;
}

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

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    font-weight: 300;
}

header p {
    font-size: 1.1em;
    opacity: 0.9;
}

main {
    padding: 40px;
}

.upload-section {
    margin-bottom: 30px;
}

.upload-area {
    border: 3px dashed #ddd;
    border-radius: 10px;
    padding: 60px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #fafafa;
}

.upload-area:hover {
    border-color: #4facfe;
    background: #f0f8ff;
}

.upload-area.dragover {
    border-color: #4facfe;
    background: #e6f3ff;
    transform: scale(1.02);
}

.upload-icon {
    font-size: 4em;
    margin-bottom: 20px;
}

.upload-area p {
    font-size: 1.2em;
    color: #666;
    margin-bottom: 10px;
}

.file-types {
    font-size: 0.9em !important;
    color: #999 !important;
}

.file-info {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    margin-top: 20px;
}

.file-info h3 {
    color: #333;
    margin-bottom: 10px;
}

.preview-section {
    margin-bottom: 30px;
}

.preview-section h3 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.5em;
}

.table-container {
    max-height: 400px;
    overflow: auto;
    border: 1px solid #ddd;
    border-radius: 8px;
    margin-bottom: 20px;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: white;
}

th, td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #eee;
    white-space: nowrap;
}

th {
    background: #f8f9fa;
    font-weight: 600;
    color: #333;
    position: sticky;
    top: 0;
    z-index: 10;
}

tr:hover {
    background: #f5f5f5;
}

.actions {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1em;
    text-decoration: none;
    display: inline-block;
    text-align: center;
    transition: all 0.3s ease;
    font-weight: 500;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(79, 172, 254, 0.4);
}

.btn-secondary {
    background: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
    color: #333;
}

.btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(168, 237, 234, 0.4);
}

.btn-success {
    background: linear-gradient(135deg, #81c784 0%, #4caf50 100%);
    color: white;
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(76, 175, 80, 0.4);
}

.result-section {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 10px;
    text-align: center;
}

.result-section h3 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.5em;
}

.result-info p {
    font-size: 1.1em;
    color: #666;
    margin-bottom: 20px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        margin: 10px;
        border-radius: 10px;
    }
    
    header {
        padding: 30px 20px;
    }
    
    header h1 {
        font-size: 2em;
    }
    
    main {
        padding: 20px;
    }
    
    .upload-area {
        padding: 40px 20px;
    }
    
    .actions {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #4facfe;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-right: 10px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}