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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: #f8fafc;
    color: #1e293b;
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

.header {
    background: linear-gradient(135deg, #1e40af 0%, #3b82f6 100%);
    color: white;
    padding: 2rem 0;
    margin-bottom: 2rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo {
    width: 60px;
    height: 60px;
    background: rgba(255,255,255,0.2);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
}

.header-text h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.header-text p {
    opacity: 0.9;
    font-size: 0.95rem;
}

.nav {
    background: white;
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 2rem;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
    border: 1px solid #e2e8f0;
}

.nav-links {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.nav a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    background: #f1f5f9;
    color: #475569;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.2s ease;
    border: 1px solid transparent;
}

.nav a:hover {
    background: #3b82f6;
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 2rem;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
    border: 1px solid #e2e8f0;
}

.card h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #374151;
    font-size: 0.9rem;
}

.form-group input, .form-group select, .form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    font-size: 0.95rem;
    transition: all 0.2s ease;
    background: white;
}

.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-group small {
    display: block;
    margin-top: 0.25rem;
    font-size: 0.8rem;
    color: #6b7280;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: #3b82f6;
    color: white;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.2s ease;
    text-decoration: none;
}

.btn:hover {
    background: #2563eb;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.btn-success {
    background: #10b981;
}

.btn-success:hover {
    background: #059669;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

.btn-danger {
    background: #ef4444;
}

.btn-danger:hover {
    background: #dc2626;
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.3);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
}

.table-container {
    overflow-x: auto;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
    margin-top: 1rem;
}

.table {
    width: 100%;
    border-collapse: collapse;
}

.table th, .table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid #e2e8f0;
}

.table th {
    background: #f8fafc;
    font-weight: 600;
    color: #374151;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.table tbody tr:hover {
    background: #f8fafc;
}

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

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
    transition: all 0.2s ease;
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.stat-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.stat-icon.blue { background: #dbeafe; }
.stat-icon.green { background: #d1fae5; }
.stat-icon.yellow { background: #fef3c7; }
.stat-icon.red { background: #fee2e2; }

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 0.5rem;
}

.stat-label {
    color: #64748b;
    font-size: 0.9rem;
    font-weight: 500;
}

.search-box {
    width: 100%;
    padding: 1rem 1.25rem;
    font-size: 1rem;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    transition: all 0.2s ease;
}

.search-box:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.alert {
    padding: 1rem 1.25rem;
    margin-bottom: 1.5rem;
    border-radius: 8px;
    border-left: 4px solid;
    font-weight: 500;
}

.alert-success {
    background: #f0fdf4;
    color: #166534;
    border-left-color: #22c55e;
}

.alert-danger {
    background: #fef2f2;
    color: #dc2626;
    border-left-color: #ef4444;
}

.alert-info {
    background: #eff6ff;
    color: #1d4ed8;
    border-left-color: #3b82f6;
}

.gecikme {
    background: #fef2f2 !important;
}

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.8rem;
    font-weight: 500;
}

.status-available {
    background: #dcfce7;
    color: #166534;
}

.status-borrowed {
    background: #fef3c7;
    color: #92400e;
}

.status-overdue {
    background: #fee2e2;
    color: #dc2626;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.quick-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.page-title {
    font-size: 1.875rem;
    font-weight: 700;
    color: #1e293b;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.search-results {
    max-height: 200px;
    overflow-y: auto;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    background: white;
    margin-top: 0.5rem;
    display: none;
}

.search-results:not(:empty) {
    display: block;
}

.search-item {
    padding: 0.75rem 1rem;
    cursor: pointer;
    border-bottom: 1px solid #f1f5f9;
    transition: background 0.2s;
}

.search-item:hover {
    background: #f8fafc;
}

.search-item:last-child {
    border-bottom: none;
}

.search-item strong {
    color: #1e293b;
}

.search-item small {
    color: #64748b;
    font-size: 0.8rem;
}

@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .nav-links {
        flex-direction: column;
    }
    
    .stats {
        grid-template-columns: 1fr;
    }
    
    .card {
        padding: 1.5rem;
    }
}