:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --dark-bg: #1f2937;
    --light-bg: #f9fafb;
    --text-dark: #111827;
    --text-light: #6b7280;
    --border-color: #e5e7eb;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
}

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

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

/* Navbar Styling */
.navbar {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    padding: 1rem 0;
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
    color: white !important;
    transition: transform 0.3s ease;
}

.navbar-brand:hover {
    transform: scale(1.05);
}

.nav-link {
    color: rgba(255, 255, 255, 0.9) !important;
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 0.5rem 1rem !important;
    border-radius: 0.375rem;
}

.nav-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: white !important;
}

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 5rem 0;
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="rgba(255,255,255,0.1)" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,122.7C672,117,768,139,864,138.7C960,139,1056,117,1152,106.7C1248,96,1344,96,1392,96L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
    background-size: cover;
}

.hero-section h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    position: relative;
    z-index: 1;
}

.hero-section p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    position: relative;
    z-index: 1;
}

/* Cards */
.card {
    border: none;
    border-radius: 1rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.07);
    transition: all 0.3s ease;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
}

.card-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    font-weight: 600;
    border: none;
    padding: 1.25rem;
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    font-weight: 600;
    border-radius: 0.5rem;
    transition: all 0.3s ease;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    box-shadow: 0 4px 6px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(37, 99, 235, 0.4);
}

.btn-success {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #059669 100%);
    box-shadow: 0 4px 6px rgba(16, 185, 129, 0.3);
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(16, 185, 129, 0.4);
}

.btn-warning {
    background: linear-gradient(135deg, var(--accent-color) 0%, #d97706 100%);
    box-shadow: 0 4px 6px rgba(245, 158, 11, 0.3);
}

.btn-warning:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(245, 158, 11, 0.4);
}

/* Forms */
.form-control, .form-select {
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 0.75rem;
    transition: all 0.3s ease;
}

.form-control:focus, .form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(37, 99, 235, 0.15);
}

.form-label {
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

/* Tables */
.table {
    background: white;
    border-radius: 0.75rem;
    overflow: hidden;
}

.table thead {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
}

.table tbody tr {
    transition: background-color 0.2s ease;
}

.table tbody tr:hover {
    background-color: rgba(37, 99, 235, 0.05);
}

/* Badges */
.badge {
    padding: 0.5rem 0.75rem;
    font-weight: 600;
    border-radius: 0.375rem;
}

/* Footer */
.footer {
    background-color: var(--dark-bg);
    color: white;
    padding: 2rem 0;
    margin-top: 4rem;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* Dashboard Sidebar */
.dashboard-sidebar {
    background: white;
    border-radius: 1rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.07);
    padding: 1.5rem;
    height: 100%;
}

.dashboard-sidebar .nav-link {
    color: var(--text-dark) !important;
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
    border-radius: 0.5rem;
    transition: all 0.3s ease;
}

.dashboard-sidebar .nav-link:hover,
.dashboard-sidebar .nav-link.active {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white !important;
}

/* File Upload Area */
.file-upload-area {
    border: 2px dashed var(--border-color);
    border-radius: 0.75rem;
    padding: 2rem;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
}

.file-upload-area:hover {
    border-color: var(--primary-color);
    background-color: rgba(37, 99, 235, 0.05);
}

.file-upload-area.dragover {
    border-color: var(--primary-color);
    background-color: rgba(37, 99, 235, 0.1);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-section h1 {
        font-size: 2rem;
    }
    
    .hero-section p {
        font-size: 1rem;
    }
}

/* Loading Spinner */
.spinner-border-sm {
    width: 1rem;
    height: 1rem;
    border-width: 0.15em;
}

/* Custom Checkbox */
.form-check-input:checked {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

/* Alert Styling */
.alert {
    border-radius: 0.75rem;
    border: none;
    padding: 1rem 1.25rem;
}

.alert-success {
    background-color: rgba(16, 185, 129, 0.1);
    color: #065f46;
}

.alert-danger {
    background-color: rgba(239, 68, 68, 0.1);
    color: #991b1b;
}

.alert-warning {
    background-color: rgba(245, 158, 11, 0.1);
    color: #92400e;
}

.alert-info {
    background-color: rgba(37, 99, 235, 0.1);
    color: #1e3a8a;
}