:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --success: #16a34a;
    --warning: #f59e0b;
    --danger: #dc2626;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-500: #6b7280;
    --gray-700: #374151;
    --gray-900: #111827;
    --radius: 8px;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-lg: 0 4px 6px rgba(0,0,0,0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--gray-50);
    color: var(--gray-900);
    line-height: 1.5;
}

/* Navbar */
.navbar {
    background: var(--primary);
    color: white;
    padding: 0 1rem;
    display: flex;
    align-items: center;
    height: 56px;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    margin-right: 2rem;
}

.nav-links {
    display: flex;
    gap: 0.5rem;
    flex: 1;
}

.nav-links a {
    color: rgba(255,255,255,0.8);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    transition: background 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
    background: rgba(255,255,255,0.2);
    color: white;
}

.nav-user {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.nav-user span {
    font-size: 0.875rem;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.5rem;
}

/* Cards */
.form-card {
    background: white;
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    margin-bottom: 1.5rem;
}

.stat-card {
    background: white;
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    text-align: center;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    color: var(--gray-500);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.25rem;
    font-size: 0.875rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 1rem;
    transition: border-color 0.2s;
}

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

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.form-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    background: white;
    color: var(--gray-700);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.btn:hover {
    background: var(--gray-50);
}

.btn-primary {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-sm {
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
}

.btn-block {
    width: 100%;
}

/* Tables */
.table-container {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}

th, td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--gray-200);
}

th {
    background: var(--gray-50);
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--gray-500);
}

tr:hover {
    background: var(--gray-50);
}

/* Badges */
.badge {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: capitalize;
}

.badge-available,
.badge-active {
    background: #dcfce7;
    color: #166534;
}

.badge-checked_out {
    background: #fef3c7;
    color: #92400e;
}

.badge-maintenance {
    background: #fee2e2;
    color: #991b1b;
}

.badge-retired,
.badge-inactive {
    background: var(--gray-100);
    color: var(--gray-500);
}

.badge-checkout {
    background: #dbeafe;
    color: #1e40af;
}

.badge-checkin {
    background: #dcfce7;
    color: #166534;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    border-bottom: 2px solid var(--gray-200);
    padding-bottom: 0.5rem;
}

.tab {
    padding: 0.5rem 1rem;
    border: none;
    background: none;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-500);
    cursor: pointer;
    border-radius: var(--radius) var(--radius) 0 0;
    transition: all 0.2s;
}

.tab:hover {
    color: var(--gray-700);
}

.tab.active {
    color: var(--primary);
    border-bottom: 2px solid var(--primary);
    margin-bottom: -2px;
}

.tab-content {
    display: none;
}

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

/* Section */
.section {
    margin-bottom: 1.5rem;
}

.section h2 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
    color: var(--gray-700);
}

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

/* Result messages */
.result-message {
    padding: 0.75rem 1rem;
    border-radius: var(--radius);
    margin-bottom: 1rem;
    font-size: 0.875rem;
}

.result-success {
    background: #dcfce7;
    color: #166534;
    border: 1px solid #bbf7d0;
}

.result-error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.error-message {
    background: #fee2e2;
    color: #991b1b;
    padding: 0.75rem;
    border-radius: var(--radius);
    margin-bottom: 1rem;
    font-size: 0.875rem;
}

/* Login */
.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 100%);
}

.login-container {
    width: 100%;
    max-width: 400px;
    padding: 1rem;
}

.login-card {
    background: white;
    border-radius: var(--radius);
    padding: 2rem;
    box-shadow: var(--shadow-lg);
}

.login-header {
    text-align: center;
    margin-bottom: 1.5rem;
}

.login-header h1 {
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.login-header p {
    color: var(--gray-500);
}

.login-footer {
    text-align: center;
    margin-top: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--gray-200);
}

.login-footer p {
    font-size: 0.75rem;
    color: var(--gray-500);
}

/* Chart */
.chart-container {
    background: white;
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

/* Responsive */
@media (max-width: 768px) {
    .navbar {
        flex-wrap: wrap;
        height: auto;
        padding: 0.5rem;
    }
    
    .nav-brand {
        margin-right: auto;
    }
    
    .nav-links {
        width: 100%;
        overflow-x: auto;
        padding: 0.5rem 0;
    }
    
    .nav-links a {
        padding: 0.5rem 0.75rem;
        font-size: 0.875rem;
    }
    
    .nav-user {
        width: 100%;
        justify-content: space-between;
        padding: 0.5rem 0;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
}