:root {
    --primary-color: #0d6efd;
    --success-color: #198754;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --info-color: #0dcaf0;
    --sidebar-width: 280px;
    --navbar-height: 60px;
}

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

body {
    background-color: #f8f9fa;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* Sidebar Styles */
.sidebar {
    position: fixed;
    top: var(--navbar-height);
    left: 0;
    width: var(--sidebar-width);
    height: calc(100vh - var(--navbar-height));
    background: linear-gradient(180deg, #1e3a5f 0%, #2c5f8a 100%);
    color: white;
    z-index: 1000;
    overflow-y: auto;
    transition: transform 0.3s ease;
    box-shadow: 2px 0 10px rgba(0,0,0,0.1);
}

.sidebar.collapsed {
    transform: translateX(-100%);
}

.sidebar-header {
    padding: 1.5rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.sidebar-header h4 {
    margin: 0;
    font-size: 1.1rem;
    font-weight: 600;
}

.sidebar-stats {
    padding: 1rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.sidebar-stat {
    background: rgba(255,255,255,0.1);
    border-radius: 8px;
    padding: 0.75rem;
    margin-bottom: 0.5rem;
    text-align: center;
}

.sidebar-stat h6 {
    font-size: 1.5rem;
    margin: 0;
    color: #ffd700;
}

.sidebar-stat small {
    opacity: 0.8;
    font-size: 0.8rem;
}

.sidebar-nav {
    list-style: none;
    padding: 0;
    margin: 1rem 0;
}

.sidebar-nav .nav-item {
    margin: 0;
}

.sidebar-nav .nav-link {
    display: block;
    padding: 0.75rem 1.5rem;
    color: rgba(255,255,255,0.8);
    text-decoration: none;
    transition: all 0.3s ease;
    border-left: 3px solid transparent;
}

.sidebar-nav .nav-link:hover,
.sidebar-nav .nav-link.active {
    background: rgba(255,255,255,0.1);
    color: white;
    border-left-color: #ffd700;
}

.sidebar-section {
    padding: 1rem;
    border-top: 1px solid rgba(255,255,255,0.1);
}

.sidebar-heading {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    opacity: 0.8;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.sidebar-category {
    display: flex;
    align-items: center;
    padding: 0.5rem;
    margin-bottom: 0.25rem;
    background: rgba(255,255,255,0.05);
    border-radius: 6px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: background 0.3s ease;
}

.sidebar-category:hover {
    background: rgba(255,255,255,0.1);
}

.sidebar-category-icon {
    width: 8px;
    height: 8px;
    background: #ffd700;
    border-radius: 50%;
    margin-right: 0.5rem;
}

/* Main Content */
.main-content {
    margin-left: var(--sidebar-width);
    margin-top: var(--navbar-height);
    padding: 2rem;
    min-height: calc(100vh - var(--navbar-height));
    transition: margin-left 0.3s ease;
}

.main-content.sidebar-collapsed {
    margin-left: 0;
}

.content-header {
    margin-bottom: 2rem;
}

.content-header h2 {
    color: #2c3e50;
    font-weight: 600;
}

/* Navbar */
.navbar {
    z-index: 1001;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

#sidebarToggle {
    border: none;
    background: rgba(255,255,255,0.1);
}

/* Tab Content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* Stats Cards */
.stat-card {
    background: linear-gradient(135deg, var(--primary-color), #0b5ed7);
    color: white;
    border-radius: 12px;
    padding: 1.5rem;
    text-align: center;
    box-shadow: 0 4px 15px rgba(13,110,253,0.2);
    border: none;
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-2px);
}

.stat-card h3 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.stat-card p {
    margin-bottom: 0;
    opacity: 0.9;
}

/* Document Cards */
.document-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
}

.document-card {
    background: white;
    border: none;
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 2px 15px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.document-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--info-color));
}

.document-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
}

.document-preview {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 1rem;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.document-preview:hover {
    transform: scale(1.02);
}

.document-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.document-meta {
    font-size: 0.9rem;
    color: #6c757d;
    margin-bottom: 0.25rem;
}

/* Category Buttons */
.category-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.category-btn {
    padding: 0.5rem 1rem;
    border: 2px solid #e9ecef;
    border-radius: 25px;
    background: white;
    color: #495057;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    font-weight: 500;
    position: relative;
    overflow: hidden;
}

.category-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.4), transparent);
    transition: left 0.5s;
}

.category-btn:hover::before {
    left: 100%;
}

.category-btn:hover,
.category-btn.active {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(13,110,253,0.3);
}

/* File Upload */
.file-upload {
    border: 2px dashed #dee2e6;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #f8f9fa;
    position: relative;
    overflow: hidden;
}

.file-upload::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(13,110,253,0.1) 0%, transparent 70%);
    transform: scale(0);
    transition: transform 0.5s ease;
}

.file-upload:hover::before {
    transform: scale(1);
}

.file-upload:hover {
    border-color: var(--primary-color);
    background: rgba(13,110,253,0.02);
}

/* Similarity Badges */
.similarity-badge {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 0.75rem;
    border-radius: 15px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.similarity-high {
    background: linear-gradient(45deg, #10b981, #059669);
    color: white;
}

.similarity-medium {
    background: linear-gradient(45deg, #f59e0b, #d97706);
    color: white;
}

.similarity-low {
    background: linear-gradient(45deg, #ef4444, #dc2626);
    color: white;
}

/* Loading Animation */
.loading {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 2px solid #f3f3f3;
    border-top: 2px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-right: 0.5rem;
}

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

/* Result Boxes */
.result-box {
    padding: 1rem;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    white-space: pre-wrap;
    word-wrap: break-word;
    border-left: 4px solid;
}

.result-success {
    background: #f0f9ff;
    border-color: #0ea5e9;
    color: #0c4a6e;
}

.result-error {
    background: #fef2f2;
    border-color: #ef4444;
    color: #991b1b;
}

.result-warning {
    background: #fffbeb;
    border-color: #f59e0b;
    color: #92400e;
}

/* Responsive Design */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .sidebar.show {
        transform: translateX(0);
    }
    
    .document-grid {
        grid-template-columns: 1fr;
    }
    
    .category-buttons {
        justify-content: center;
    }
}

/* Custom Scrollbar */
.sidebar::-webkit-scrollbar {
    width: 6px;
}

.sidebar::-webkit-scrollbar-track {
    background: rgba(255,255,255,0.1);
}

.sidebar::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.3);
    border-radius: 3px;
}

.sidebar::-webkit-scrollbar-thumb:hover {
    background: rgba(255,255,255,0.5);
}