/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 20px 30px;
    border-radius: 8px;
    margin-bottom: 30px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 2em;
    margin-bottom: 10px;
}

nav {
    display: flex;
    gap: 20px;
}

nav a {
    color: white;
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 4px;
    transition: background-color 0.3s;
}

nav a:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

/* Main Content */
main {
    flex: 1;
    background: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

/* Messages */
.messages {
    margin-bottom: 20px;
}

.alert {
    padding: 15px;
    border-radius: 4px;
    margin-bottom: 15px;
}

.alert-error {
    background-color: #fee;
    color: #c33;
    border: 1px solid #fcc;
}

.alert-warning {
    background-color: #fff3cd;
    color: #856404;
    border: 1px solid #ffeaa7;
}

.alert-success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

/* Forms */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
}

.form-control {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
    transition: border-color 0.3s;
}

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

.form-help {
    display: block;
    margin-top: 5px;
    font-size: 0.9em;
    color: #666;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background-color: #667eea;
    color: white;
}

.btn-primary:hover {
    background-color: #5568d3;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(102, 126, 234, 0.3);
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background-color: #5a6268;
}

.actions {
    margin-top: 30px;
    display: flex;
    gap: 15px;
}

/* Tables */
.table-container {
    overflow-x: auto;
    margin: 20px 0;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: white;
}

.data-table th {
    background-color: #667eea;
    color: white;
    padding: 12px;
    text-align: left;
    font-weight: 600;
}

.data-table td {
    padding: 10px 12px;
    border-bottom: 1px solid #eee;
}

.data-table tr:hover {
    background-color: #f8f9fa;
}

/* Info Boxes */
.info-box, .metrics-box {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: 4px;
    margin: 20px 0;
    border-left: 4px solid #667eea;
}

.info-box h3, .metrics-box h3 {
    margin-bottom: 15px;
    color: #667eea;
}

.metrics-table {
    width: 100%;
}

.metrics-table td {
    padding: 8px 0;
    border-bottom: 1px solid #e0e0e0;
}

.metrics-table td:first-child {
    width: 200px;
}

/* Sections */
.upload-section, .preview-section, .config-section, .train-section, .test-section, .results-section {
    max-width: 800px;
    margin: 0 auto;
}

.upload-section h2, .preview-section h2, .config-section h2, 
.train-section h2, .test-section h2, .results-section h2 {
    margin-bottom: 20px;
    color: #667eea;
}

/* Footer */
footer {
    margin-top: 30px;
    text-align: center;
    color: #666;
    padding: 20px;
}

/* Code */
code {
    background-color: #f4f4f4;
    padding: 2px 6px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    header {
        padding: 15px 20px;
    }
    
    header h1 {
        font-size: 1.5em;
    }
    
    nav {
        flex-direction: column;
        gap: 10px;
    }
    
    main {
        padding: 20px;
    }
    
    .actions {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        text-align: center;
    }
}