:root {
    --primary-color: #2563eb;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --text-color: #1f2937;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --border-color: #e5e7eb;
    --input-bg: #f3f4f6;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 1px 3px rgba(0, 0, 0, 0.06);
    --gradient-bg: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
}

/* Container styles */
.main-container {
    padding: 2rem 1rem;
    max-width: 1200px;
    margin: 0 auto;
}

/* Header styles */
.header-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 1rem;
}

.header-subtitle {
    font-size: 1.125rem;
    color: #6b7280;
    max-width: 600px;
    margin: 0 auto 2rem;
    line-height: 1.7;
}

/* Upload area styles */
.upload-area {
    background: white;
    border-radius: 1rem;
    padding: 3rem 2rem;
    box-shadow: var(--shadow-md);
    border: 2px dashed var(--border-color);
    transition: all 0.3s ease;
    margin-bottom: 2rem;
}

.upload-area:hover {
    border-color: var(--primary-color);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.15);
}

.upload-icon {
    text-align: center;
    margin-bottom: 1.5rem;
}

.upload-icon i {
    font-size: 3rem;
    color: var(--primary-color);
}

/* File upload sections */
.file-upload-section {
    background: #f8fafc;
    border-radius: 0.75rem;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    transition: all 0.2s ease;
}

.file-upload-section:hover {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.file-upload-section .form-label {
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 0.75rem;
}

.file-upload-section .form-control {
    border: 2px dashed var(--border-color);
    background: white;
    padding: 0.75rem;
    border-radius: 0.5rem;
    transition: all 0.2s ease;
}

.file-upload-section .form-control:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.file-upload-section .form-text {
    font-size: 0.875rem;
    color: #6b7280;
    margin-top: 0.5rem;
}

/* Step cards */
.step-card {
    text-align: center;
    padding: 2rem 1rem;
    background: white;
    border-radius: 0.75rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    height: 100%;
    transition: all 0.3s ease;
}

.step-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 3rem;
    height: 3rem;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.step-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 0.75rem;
}

.step-description {
    color: #6b7280;
    font-size: 0.875rem;
    line-height: 1.6;
    margin: 0;
}

/* Info cards */
.info-card {
    margin-bottom: 2rem;
}

.info-card .card {
    border: none;
    box-shadow: var(--shadow-sm);
    border-radius: 0.75rem;
    overflow: hidden;
}

.info-card .card-header {
    background: var(--gradient-bg);
    color: white;
    border: none;
    padding: 1rem 1.5rem;
}

.info-card .card-header h5 {
    margin: 0;
    font-weight: 600;
}

.info-card .card-body {
    padding: 1.5rem;
}

/* Button styles */
.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    font-weight: 500;
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
    transition: all 0.2s ease;
}

.btn-primary:hover {
    background-color: #1d4ed8;
    border-color: #1d4ed8;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.btn-success {
    background-color: var(--success-color);
    border-color: var(--success-color);
    font-weight: 500;
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
}

.btn-success:hover {
    background-color: #059669;
    border-color: #059669;
}

/* Results area styles */
#result {
    margin-top: 2rem;
}

/* Comment section styles */
#commentSection {
    background: white;
    border-radius: 0.75rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

#commentSection .card-body {
    padding: 1.5rem;
}

#commentSection .card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 1rem;
}

#commentSection textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background-color: var(--input-bg);
    resize: vertical;
    min-height: 100px;
    transition: all 0.2s ease;
}

#commentSection textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Action buttons styles */
#actionButtons {
    margin-top: 1.5rem;
}

#actionButtons .btn {
    min-width: 200px;
    font-weight: 600;
    letter-spacing: 0.025em;
}

/* Table styles for compatibility with existing JavaScript */
table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin: 1.5rem 0;
    background-color: var(--card-bg);
    border-radius: 0.75rem;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

th, td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: var(--input-bg);
    font-weight: 600;
}

tr:last-child td {
    border-bottom: none;
}

/* Input styles for compatibility */
input[type="number"] {
    width: 80px;
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 0.375rem;
    background-color: var(--input-bg);
}

.editable {
    background-color: var(--input-bg);
    transition: all 0.2s;
}

.editable:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Collapsible styles for compatibility */
.collapsible-header {
    cursor: pointer;
    display: flex;
    align-items: center;
    user-select: none;
}

.collapsible-header::after {
    content: '▼';
    margin-left: 10px;
    font-size: 0.8rem;
    transition: transform 0.3s ease;
}

.collapsible-header.collapsed::after {
    transform: rotate(-90deg);
}

.collapsible-content {
    overflow: hidden;
    transition: max-height 0.3s ease;
    max-height: 2000px;
}

.collapsible-content.collapsed {
    max-height: 0;
}

/* Download button styles for compatibility */
.download-button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background-color: var(--success-color);
    color: white;
    border: none;
    border-radius: 0.375rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
    font-size: 0.875rem;
}

.download-button:hover {
    background-color: #059669;
    color: white;
}

/* Card header styles for compatibility */
.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding: 1rem 1.5rem;
    background: var(--input-bg);
    border-radius: 0.75rem 0.75rem 0 0;
}

.card-header h2 {
    margin: 0;
    font-size: 1.25rem;
    font-weight: 600;
}

/* Loading spinner animation */
@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-spinner {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
    margin-right: 0.5rem;
}

/* Hidden class for compatibility - MUST NOT USE !important to allow JavaScript show */
.hidden {
    display: none;
}

/* Alert styles */
.alert {
    border-radius: 0.5rem;
    border: none;
}

.alert-info {
    background-color: #eff6ff;
    color: #1e40af;
    border-left: 4px solid #3b82f6;
}

/* Responsive design */
@media (max-width: 768px) {
    .main-container {
        padding: 1rem;
    }
    
    .header-title {
        font-size: 2rem;
    }
    
    .upload-area {
        padding: 2rem 1rem;
    }
    
    .step-card {
        margin-bottom: 1rem;
    }
}

@media (max-width: 576px) {
    .header-title {
        font-size: 1.75rem;
    }
    
    .upload-icon i {
        font-size: 2rem;
    }
    
    .file-upload-section {
        padding: 1rem;
    }
}