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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background-color: white;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

header {
    background: linear-gradient(90deg, #4b6cb7 0%, #182848 100%);
    color: white;
    padding: 2rem;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    font-weight: 300;
}

main {
    padding: 2rem;
}

.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background-color: #f8f9fa;
    border-radius: 8px;
    border: 1px solid #eaeaea;
}

.file-input-container {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.file-input-container label {
    font-weight: 600;
    color: #182848;
}

.file-input {
    padding: 0.75rem 1rem;
    border: 2px solid #4b6cb7;
    border-radius: 6px;
    background-color: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.file-input:hover {
    border-color: #182848;
    background-color: #f8f9ff;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.95rem;
}

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

.btn.secondary:hover {
    background-color: #545b62;
    transform: translateY(-2px);
}

.table-info {
    display: flex;
    gap: 2rem;
    font-weight: 500;
    color: #495057;
}

.table-info div {
    padding: 0.5rem 1rem;
    background-color: white;
    border-radius: 4px;
    border: 1px solid #dee2e6;
}

.table-container {
    margin-bottom: 2rem;
    border-radius: 8px;
    overflow-x: scroll;
    overflow-y: hidden;
    border: 1px solid #dee2e6;
}

.dataTables_wrapper {
    padding: 0;
}

.dataTables_filter input {
    border: 2px solid #4b6cb7 !important;
    border-radius: 4px !important;
    padding: 0.5rem !important;
    margin-left: 0.5rem !important;
}

.dataTables_length select {
    border: 2px solid #4b6cb7 !important;
    border-radius: 4px !important;
    padding: 0.25rem !important;
}

th {
    background-color: #4b6cb7 !important;
    color: white !important;
    font-weight: 600 !important;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.9rem;
}

th:hover {
    background-color: #3a5795 !important;
    cursor: pointer;
}

tr:nth-child(even) {
    background-color: #f8f9fa !important;
}

tr:hover {
    background-color: #e9ecef !important;
}

.json-preview {
    margin-top: 2rem;
    padding: 1.5rem;
    background-color: #f8f9fa;
    border-radius: 8px;
    border: 1px solid #eaeaea;
}

.json-preview h3 {
    margin-bottom: 1rem;
    color: #182848;
    font-size: 1.25rem;
}

#jsonPreview {
    background-color: #2d3748;
    color: #e2e8f0;
    padding: 1.5rem;
    border-radius: 6px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
    max-height: 300px;
    overflow-y: auto;
    white-space: pre-wrap;
    word-wrap: break-word;
}

footer {
    text-align: center;
    padding: 1.5rem;
    background-color: #f8f9fa;
    color: #6c757d;
    font-size: 0.9rem;
    border-top: 1px solid #eaeaea;
}

/* Responsive design */
@media (max-width: 768px) {
    .controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    .file-input-container {
        flex-direction: column;
        align-items: stretch;
    }
    
    .file-input-container label {
        text-align: center;
    }
    
    .table-info {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    header h1 {
        font-size: 2rem;
    }
}