/**
 * Admin Base Styles
 * Variables, reset, typography, forms, buttons, cards, utilities
 */

/* ========================================
   CSS Variables
   ======================================== */
:root {
    /* Colors */
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --primary-light: #dbeafe;
    
    --success: #22c55e;
    --success-hover: #16a34a;
    --success-light: #dcfce7;
    
    --danger: #ef4444;
    --danger-hover: #dc2626;
    --danger-light: #fee2e2;
    
    --warning: #f59e0b;
    --warning-hover: #d97706;
    --warning-light: #fef3c7;
    
    --info: #06b6d4;
    --info-light: #cffafe;
    
    /* Grays */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    
    /* Layout */
    --topbar-height: 60px;
    --nav-height: 50px;
    --sidebar-width: 240px;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    
    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
}

/* ========================================
   Reset
   ======================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    font-size: 0.9375rem;
    line-height: 1.5;
    color: var(--gray-800);
    background-color: var(--gray-100);
}

/* ========================================
   Typography
   ======================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.25;
    color: var(--gray-900);
}

h1 { font-size: 1.875rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.125rem; }
h5 { font-size: 1rem; }
h6 { font-size: 0.875rem; }

p { margin-bottom: var(--space-md); }
p:last-child { margin-bottom: 0; }

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-hover);
}

/* ========================================
   Layout
   ======================================== */
.admin-wrapper {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.admin-content {
    flex: 1;
    padding: var(--space-xl);
    margin-top: calc(var(--topbar-height) + var(--nav-height));
    max-width: 1400px;
    margin-left: auto;
    margin-right: auto;
    width: 100%;
}

.admin-footer {
    padding: var(--space-md) var(--space-xl);
    text-align: center;
    color: var(--gray-500);
    font-size: 0.8125rem;
    border-top: 1px solid var(--gray-200);
    background: white;
}

/* ========================================
   Page Header
   ======================================== */
.page-header {
    margin-bottom: var(--space-xl);
}

.page-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.page-subtitle {
    color: var(--gray-500);
    font-size: 0.9375rem;
}

.page-header-actions {
    display: flex;
    gap: var(--space-sm);
    margin-top: var(--space-md);
}

/* ========================================
   Cards
   ======================================== */
.card {
    background: white;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
}

.card-header {
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.card-title {
    font-size: 1rem;
    font-weight: 600;
}

.card-body {
    padding: var(--space-lg);
}

.card-footer {
    padding: var(--space-md) var(--space-lg);
    border-top: 1px solid var(--gray-200);
    background: var(--gray-50);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
}

/* ========================================
   Buttons
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    line-height: 1.5;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    color: white;
}

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

.btn-success:hover:not(:disabled) {
    background: var(--success-hover);
    color: white;
}

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

.btn-danger:hover:not(:disabled) {
    background: var(--danger-hover);
    color: white;
}

.btn-secondary {
    background: white;
    color: var(--gray-700);
    border-color: var(--gray-300);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--gray-50);
    color: var(--gray-900);
}

.btn-sm {
    padding: 0.25rem 0.75rem;
    font-size: 0.8125rem;
}

.btn-lg {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
}

.btn-icon {
    padding: 0.5rem;
    width: 36px;
    height: 36px;
}

/* ========================================
   Forms
   ======================================== */
.form-group {
    margin-bottom: var(--space-lg);
}

.form-label {
    display: block;
    margin-bottom: var(--space-sm);
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--gray-700);
}

.form-input,
.form-select,
.form-textarea {
    display: block;
    width: 100%;
    padding: 0.5rem 0.75rem;
    font-size: 0.9375rem;
    line-height: 1.5;
    color: var(--gray-800);
    background: white;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.form-textarea {
    min-height: 120px;
    resize: vertical;
}

.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    padding-right: 2.5rem;
}

.form-checkbox,
.form-radio {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    cursor: pointer;
}

.form-checkbox input,
.form-radio input {
    width: 18px;
    height: 18px;
    accent-color: var(--primary);
}

.form-hint {
    margin-top: var(--space-xs);
    font-size: 0.8125rem;
    color: var(--gray-500);
}

.form-error {
    margin-top: var(--space-xs);
    font-size: 0.8125rem;
    color: var(--danger);
}

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

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

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

.table th {
    font-weight: 600;
    font-size: 0.8125rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--gray-500);
    background: var(--gray-50);
}

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

/* ========================================
   Alerts & Messages
   ======================================== */
.alert {
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-lg);
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
}

.alert-success {
    background: var(--success-light);
    color: var(--success-hover);
    border: 1px solid var(--success);
}

.alert-danger {
    background: var(--danger-light);
    color: var(--danger-hover);
    border: 1px solid var(--danger);
}

.alert-warning {
    background: var(--warning-light);
    color: var(--warning-hover);
    border: 1px solid var(--warning);
}

.alert-info {
    background: var(--info-light);
    color: var(--info);
    border: 1px solid var(--info);
}

/* ========================================
   Badges
   ======================================== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.125rem 0.5rem;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: var(--radius-full);
}

.badge-success {
    background: var(--success-light);
    color: var(--success-hover);
}

.badge-danger {
    background: var(--danger-light);
    color: var(--danger-hover);
}

.badge-warning {
    background: var(--warning-light);
    color: var(--warning-hover);
}

.badge-info {
    background: var(--primary-light);
    color: var(--primary-hover);
}

.badge-gray {
    background: var(--gray-200);
    color: var(--gray-600);
}

/* ========================================
   Grid
   ======================================== */
.grid {
    display: grid;
    gap: var(--space-lg);
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 1024px) {
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
    .grid-4, .grid-3, .grid-2 { grid-template-columns: 1fr; }
}

/* ========================================
   Utilities
   ======================================== */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-muted { color: var(--gray-500); }
.text-success { color: var(--success); }
.text-danger { color: var(--danger); }
.text-sm { font-size: 0.8125rem; }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--space-sm); }
.mt-2 { margin-top: var(--space-md); }
.mt-3 { margin-top: var(--space-lg); }
.mt-4 { margin-top: var(--space-xl); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--space-sm); }
.mb-2 { margin-bottom: var(--space-md); }
.mb-3 { margin-bottom: var(--space-lg); }
.mb-4 { margin-bottom: var(--space-xl); }

.d-flex { display: flex; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: var(--space-sm); }
.gap-2 { gap: var(--space-md); }
.gap-3 { gap: var(--space-lg); }

.hidden { display: none !important; }

/* ========================================
   Modals
   ======================================== */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow: hidden;
    transform: scale(0.9);
    transition: transform var(--transition-normal);
}

.modal-overlay.active .modal {
    transform: scale(1);
}

.modal-header {
    padding: var(--space-lg);
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-title {
    font-size: 1.125rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--gray-400);
    line-height: 1;
}

.modal-close:hover {
    color: var(--gray-600);
}

.modal-body {
    padding: var(--space-lg);
    overflow-y: auto;
    max-height: calc(90vh - 140px);
}

.modal-footer {
    padding: var(--space-md) var(--space-lg);
    border-top: 1px solid var(--gray-200);
    display: flex;
    justify-content: flex-end;
    gap: var(--space-sm);
    background: var(--gray-50);
}

/* ========================================
   Loading States
   ======================================== */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--gray-200);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.skeleton {
    background: linear-gradient(90deg, var(--gray-200) 25%, var(--gray-100) 50%, var(--gray-200) 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: var(--radius-sm);
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}