:root {
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --secondary: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  --bg: #f3f4f6;
  --card-bg: #ffffff;
  --text: #111827;
  --text-muted: #6b7280;
  --border: #e5e7eb;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --radius: 12px;
  --sidebar-width: 260px;
}

[data-theme="dark"] {
  --bg: #0f172a;
  --card-bg: #1e293b;
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --border: #334155;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.5);
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; }

body { background-color: var(--bg); color: var(--text); transition: background-color 0.3s, color 0.3s; }

.hidden { display: none !important; }

/* Loading Overlay */
#loading-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.5); display: flex; justify-content: center; align-items: center; z-index: 9999; }
.spinner { width: 40px; height: 40px; border: 4px solid var(--border); border-top-color: var(--primary); border-radius: 50%; animation: spin 1s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* Offline Indicator */
#offline-indicator { position: fixed; bottom: 20px; right: 20px; background: var(--danger); color: white; padding: 10px 20px; border-radius: var(--radius); font-weight: 600; z-index: 1000; box-shadow: var(--shadow); }

/* Auth Container */
#auth-container { min-height: 100vh; display: flex; justify-content: center; align-items: center; background: linear-gradient(135deg, var(--primary), #818cf8); }
.auth-box { background: var(--card-bg); padding: 40px; border-radius: var(--radius); box-shadow: var(--shadow); width: 100%; max-width: 420px; }
.auth-box h1 { font-size: 1.8rem; margin-bottom: 8px; color: var(--primary); }
.auth-box p { color: var(--text-muted); margin-bottom: 24px; }
.form-group { margin-bottom: 16px; }
.form-group label { display: block; margin-bottom: 6px; font-weight: 500; font-size: 0.9rem; }
.form-control { width: 100%; padding: 10px 14px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg); color: var(--text); font-size: 1rem; transition: border-color 0.2s; }
.form-control:focus { outline: none; border-color: var(--primary); }
.btn { width: 100%; padding: 12px; border: none; border-radius: 8px; font-size: 1rem; font-weight: 600; cursor: pointer; transition: opacity 0.2s, transform 0.1s; }
.btn:active { transform: scale(0.98); }
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-hover); }
.btn-secondary { background: var(--secondary); color: white; margin-top: 10px; }
.btn-danger { background: var(--danger); color: white; }
.btn-sm { padding: 6px 12px; font-size: 0.85rem; width: auto; }
.auth-footer { margin-top: 20px; text-align: center; font-size: 0.9rem; color: var(--text-muted); }
.auth-footer a { color: var(--primary); cursor: pointer; text-decoration: none; }

/* Layout */
#main-app { display: flex; min-height: 100vh; }

/* Sidebar */
#sidebar { width: var(--sidebar-width); background: var(--card-bg); border-right: 1px solid var(--border); display: flex; flex-direction: column; position: fixed; height: 100vh; transition: transform 0.3s; z-index: 100; }
.sidebar-header { padding: 20px; display: flex; align-items: center; gap: 12px; border-bottom: 1px solid var(--border); }
.sidebar-header i { font-size: 1.5rem; color: var(--primary); }
.sidebar-header h2 { font-size: 1.25rem; }
.nav-menu { list-style: none; padding: 10px; flex: 1; overflow-y: auto; }
.nav-item { margin-bottom: 4px; }
.nav-link { display: flex; align-items: center; gap: 12px; padding: 12px 16px; border-radius: 8px; color: var(--text-muted); text-decoration: none; font-weight: 500; cursor: pointer; transition: background 0.2s, color 0.2s; }
.nav-link:hover, .nav-link.active { background: rgba(79, 70, 229, 0.1); color: var(--primary); }
.nav-link i { width: 24px; text-align: center; }
.sidebar-footer { padding: 20px; border-top: 1px solid var(--border); }
.user-profile { display: flex; align-items: center; gap: 10px; }
.user-avatar { width: 36px; height: 36px; border-radius: 50%; background: var(--primary); color: white; display: flex; justify-content: center; align-items: center; font-weight: 600; }
.user-info { flex: 1; }
.user-info p { font-size: 0.85rem; font-weight: 600; }
.user-info span { font-size: 0.75rem; color: var(--text-muted); }

/* Content */
#content { flex: 1; margin-left: var(--sidebar-width); padding: 24px; overflow-y: auto; height: 100vh; }
.page-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 24px; flex-wrap: wrap; gap: 16px; }
.page-header h1 { font-size: 1.5rem; }
.search-box { position: relative; }
.search-box input { padding: 10px 14px 10px 36px; border: 1px solid var(--border); border-radius: 8px; background: var(--card-bg); color: var(--text); width: 300px; }
.search-box i { position: absolute; left: 12px; top: 50%; transform: translateY(-50%); color: var(--text-muted); }

/* Cards */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 20px; margin-bottom: 24px; }
.stat-card { background: var(--card-bg); padding: 20px; border-radius: var(--radius); box-shadow: var(--shadow); display: flex; flex-direction: column; gap: 8px; border-left: 4px solid var(--primary); }
.stat-card.occupied { border-left-color: var(--secondary); }
.stat-card.vacant { border-left-color: var(--warning); }
.stat-card.income { border-left-color: var(--primary); }
.stat-card.pending { border-left-color: var(--danger); }
.stat-card h3 { font-size: 0.9rem; color: var(--text-muted); font-weight: 500; }
.stat-card p { font-size: 1.5rem; font-weight: 700; }
.stat-card span { font-size: 0.8rem; color: var(--text-muted); }

/* Tables */
.data-table { width: 100%; border-collapse: collapse; background: var(--card-bg); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
.data-table th, .data-table td { padding: 14px 16px; text-align: left; border-bottom: 1px solid var(--border); }
.data-table th { background: rgba(0,0,0,0.02); font-weight: 600; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.5px; color: var(--text-muted); }
.data-table tr:hover { background: rgba(0,0,0,0.01); }
.badge { padding: 4px 10px; border-radius: 20px; font-size: 0.75rem; font-weight: 600; }
.badge-success { background: rgba(16, 185, 129, 0.1); color: var(--secondary); }
.badge-warning { background: rgba(245, 158, 11, 0.1); color: var(--warning); }
.badge-danger { background: rgba(239, 68, 68, 0.1); color: var(--danger); }

/* Modal */
.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.5); display: flex; justify-content: center; align-items: center; z-index: 1000; opacity: 0; pointer-events: none; transition: opacity 0.3s; }
.modal-overlay.active { opacity: 1; pointer-events: all; }
.modal-content { background: var(--card-bg); padding: 24px; border-radius: var(--radius); width: 90%; max-width: 600px; max-height: 90vh; overflow-y: auto; box-shadow: var(--shadow); transform: translateY(-20px); transition: transform 0.3s; }
.modal-overlay.active .modal-content { transform: translateY(0); }
.modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.modal-header h2 { font-size: 1.25rem; }
.close-btn { background: none; border: none; font-size: 1.25rem; cursor: pointer; color: var(--text-muted); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 768px) { .form-row { grid-template-columns: 1fr; } }

/* Charts */
.chart-container { background: var(--card-bg); padding: 20px; border-radius: var(--radius); box-shadow: var(--shadow); margin-bottom: 24px; }

/* Filters */
.filter-bar { display: flex; gap: 12px; margin-bottom: 20px; flex-wrap: wrap; }
.filter-bar select, .filter-bar input { padding: 8px 12px; border: 1px solid var(--border); border-radius: 8px; background: var(--card-bg); color: var(--text); }

/* Toast */
.toast-container { position: fixed; top: 20px; right: 20px; z-index: 2000; display: flex; flex-direction: column; gap: 10px; }
.toast { background: var(--card-bg); padding: 14px 20px; border-radius: 8px; box-shadow: var(--shadow); display: flex; align-items: center; gap: 10px; border-left: 4px solid var(--primary); animation: slideIn 0.3s ease-out; }
.toast.success { border-left-color: var(--secondary); }
.toast.error { border-left-color: var(--danger); }
@keyframes slideIn { from { transform: translateX(100%); opacity: 0; } to { transform: translateX(0); opacity: 1; } }

/* Responsive */
@media (max-width: 1024px) {
  #sidebar { transform: translateX(-100%); }
  #sidebar.open { transform: translateX(0); }
  #content { margin-left: 0; }
  .menu-toggle { display: block; }
}
@media (min-width: 1025px) { .menu-toggle { display: none; } }

/* Animations */
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
.page-section { animation: fadeIn 0.4s ease-out; }

/* Print */
@media print { #sidebar, .no-print { display: none !important; } #content { margin-left: 0; } }