/**
 * ZOChat - Minimalistic Design System
 * Clean, fast, mobile-first
 * Version: 1.0.0
 */

/* =====================================================
   CSS Variables - Clean Palette
   ===================================================== */
:root {
    /* Primary Colors - Clean Blue */
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: #3b82f6;
    
    /* Neutrals - Grayscale */
    --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;
    
    /* Semantic */
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;
    
    /* Background */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    
    /* Text */
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    
    /* Borders */
    --border: #e5e7eb;
    --border-light: #f3f4f6;
    
    /* Shadows - Subtle */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    
    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-md: 0.625rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition: 200ms ease;
    --transition-slow: 300ms ease;
}

/* =====================================================
   Reset & Base
   ===================================================== */
*, *::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: var(--font-sans);
    font-size: 1rem;
    line-height: 1.5;
    color: var(--text-primary);
    background: var(--bg-secondary);
    min-height: 100vh;
}

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

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.125rem; }

p { color: var(--text-secondary); }

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

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

/* =====================================================
   Layout - Mobile First
   ===================================================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-4);
}

@media (min-width: 768px) {
    .container { padding: 0 var(--space-6); }
}

/* =====================================================
   Cards
   ===================================================== */
.card {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.card-body {
    padding: var(--space-4);
}

@media (min-width: 768px) {
    .card-body { padding: var(--space-6); }
}

/* =====================================================
   Buttons
   ===================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    font-size: 0.875rem;
    font-weight: 500;
    line-height: 1.5;
    border-radius: var(--radius);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

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

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

.btn-secondary {
    background: var(--bg-primary);
    color: var(--text-primary);
    border-color: var(--border);
}

.btn-secondary:hover {
    background: var(--bg-secondary);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
}

.btn-ghost:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.btn-lg {
    padding: var(--space-3) var(--space-6);
    font-size: 1rem;
}

.btn-block {
    width: 100%;
}

/* =====================================================
   Forms
   ===================================================== */
.form-group {
    margin-bottom: var(--space-4);
}

.form-label {
    display: block;
    margin-bottom: var(--space-2);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-input {
    width: 100%;
    padding: var(--space-3);
    font-size: 1rem;
    line-height: 1.5;
    color: var(--text-primary);
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

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

.form-input::placeholder {
    color: var(--text-muted);
}

.form-input-error {
    border-color: var(--danger);
}

.form-error {
    margin-top: var(--space-1);
    font-size: 0.75rem;
    color: var(--danger);
}

/* =====================================================
   Auth Pages - Clean Design
   ===================================================== */
.auth-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: var(--space-4);
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--gray-100) 100%);
}

.auth-container {
    width: 100%;
    max-width: 400px;
}

.auth-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    padding: var(--space-6);
}

.auth-header {
    text-align: center;
    margin-bottom: var(--space-6);
}

.auth-logo {
    width: 48px;
    height: 48px;
    margin-bottom: var(--space-4);
    background: var(--primary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    font-weight: 700;
}

.auth-title {
    font-size: 1.5rem;
    margin-bottom: var(--space-2);
}

.auth-subtitle {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.auth-footer {
    margin-top: var(--space-4);
    text-align: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.auth-divider {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin: var(--space-4) 0;
    color: var(--text-muted);
    font-size: 0.75rem;
}

.auth-divider::before,
.auth-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border);
}

/* =====================================================
   Alerts
   ===================================================== */
.alert {
    padding: var(--space-3) var(--space-4);
    border-radius: var(--radius);
    font-size: 0.875rem;
    margin-bottom: var(--space-4);
}

.alert-error {
    background: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.alert-success {
    background: #f0fdf4;
    color: #166534;
    border: 1px solid #bbf7d0;
}

.alert-info {
    background: #eff6ff;
    color: #1e40af;
    border: 1px solid #bfdbfe;
}

/* =====================================================
   Dashboard Layout
   ===================================================== */
.dashboard {
    min-height: 100vh;
    background: var(--bg-secondary);
}

.dashboard-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    padding: var(--space-3) var(--space-4);
}

.dashboard-nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
}

.dashboard-logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
}

.dashboard-main {
    padding: var(--space-4);
}

@media (min-width: 768px) {
    .dashboard-main {
        padding: var(--space-6);
    }
}

/* =====================================================
   Grid System
   ===================================================== */
.grid {
    display: grid;
    gap: var(--space-4);
}

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }

@media (min-width: 640px) {
    .sm\:grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 768px) {
    .md\:grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
    .md\:grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 1024px) {
    .lg\:grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
    .lg\:grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
}

/* =====================================================
   Stats Cards
   ===================================================== */
.stat-card {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
}

.stat-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-3);
}

.stat-icon.primary { background: #eff6ff; color: var(--primary); }
.stat-icon.success { background: #f0fdf4; color: var(--success); }
.stat-icon.warning { background: #fffbeb; color: var(--warning); }
.stat-icon.danger { background: #fef2f2; color: var(--danger); }

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-1);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* =====================================================
   Navigation
   ===================================================== */
.nav {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-2) var(--space-3);
    color: var(--text-secondary);
    border-radius: var(--radius);
    transition: all var(--transition-fast);
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
}

.nav-link:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.nav-link.active {
    background: var(--primary);
    color: white;
}

.nav-link i {
    width: 20px;
    text-align: center;
}

/* =====================================================
   Utilities
   ===================================================== */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-muted { color: var(--text-muted); }
.text-sm { font-size: 0.875rem; }
.text-xs { font-size: 0.75rem; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }

.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }

.hidden { display: none; }

@media (min-width: 768px) {
    .md\:hidden { display: none; }
    .md\:block { display: block; }
    .md\:flex { display: flex; }
}

/* =====================================================
   Badges
   ===================================================== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: var(--space-1) var(--space-2);
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: var(--radius-full);
}

.badge-primary {
    background: #eff6ff;
    color: var(--primary);
}

.badge-success {
    background: #f0fdf4;
    color: var(--success);
}

.badge-warning {
    background: #fffbeb;
    color: var(--warning);
}

.badge-danger {
    background: #fef2f2;
    color: var(--danger);
}

/* =====================================================
   Tables
   ===================================================== */
.table-container {
    overflow-x: auto;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}

.table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

.table th,
.table td {
    padding: var(--space-3) var(--space-4);
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.table th {
    background: var(--bg-secondary);
    font-weight: 600;
    color: var(--text-primary);
}

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

.table tr:hover td {
    background: var(--bg-secondary);
}

/* =====================================================
   Mobile Menu
   ===================================================== */
.mobile-menu-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: transparent;
    border: none;
    border-radius: var(--radius);
    color: var(--text-primary);
    cursor: pointer;
}

.mobile-menu-btn:hover {
    background: var(--bg-secondary);
}

@media (min-width: 768px) {
    .mobile-menu-btn {
        display: none;
    }
}

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

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

.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-8);
    color: var(--text-muted);
}

/* =====================================================
   Footer
   ===================================================== */
.footer {
    padding: var(--space-4);
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-muted);
    border-top: 1px solid var(--border);
    margin-top: auto;
}