:root {
  --primary: #3498db;
  --secondary: #2c3e50;
  --success: #27ae60;
  --error: #e74c3c;
  --warning: #e67e22;
  --bg: #ecf0f1;
  --text: #333333;
  --border: #d7dee2;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", Tahoma, sans-serif;
  color: var(--text);
  background: var(--bg);
}

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

.admin-shell { display: flex; min-height: 100vh; }

.sidebar {
  width: 220px;
  flex-shrink: 0;
  background: var(--secondary);
  color: #fff;
  display: flex;
  flex-direction: column;
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px;
  font-weight: 700;
  font-size: 1.1rem;
  border-bottom: 1px solid rgba(255,255,255,0.15);
}

.sidebar-logo { height: 32px; width: auto; }

.sidebar nav { display: flex; flex-direction: column; padding: 12px 0; flex: 1; }

.nav-link {
  padding: 10px 16px;
  color: #cfd8dc;
  text-decoration: none;
  font-size: 0.92rem;
}

.nav-link:hover { background: rgba(255,255,255,0.08); color: #fff; }
.nav-link.active { background: var(--primary); color: #fff; font-weight: 600; }

.sidebar-logout { padding: 12px 16px; }
.sidebar-logout button {
  width: 100%;
  padding: 8px;
  background: transparent;
  border: 1px solid rgba(255,255,255,0.3);
  color: #fff;
  border-radius: 4px;
  cursor: pointer;
}
.sidebar-logout button:hover { background: rgba(255,255,255,0.1); }

.main { flex: 1; display: flex; flex-direction: column; min-width: 0; }

.topbar {
  height: 60px;
  background: #fff;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
}

.topbar h1 { font-size: 1.2rem; margin: 0; }
.topbar-right { display: flex; align-items: center; gap: 16px; }
.topbar-user { font-size: 0.85rem; color: #7f8c8d; }
.topbar-bell {
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff;
  background: var(--error);
  padding: 4px 10px;
  border-radius: 12px;
  text-decoration: none;
  animation: bell-pulse 1.2s ease-in-out infinite;
}
@keyframes bell-pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.6; } }

.content { padding: 24px; flex: 1; overflow-x: auto; }

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px;
  margin-bottom: 20px;
}

.card h2 { margin-top: 0; font-size: 1.05rem; }

.btn {
  display: inline-block;
  padding: 8px 16px;
  border: none;
  border-radius: 4px;
  font-size: 0.9rem;
  cursor: pointer;
  text-decoration: none;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-secondary { background: #bdc3c7; color: #222; }
.btn-danger { background: var(--error); color: #fff; }
.btn-success { background: var(--success); color: #fff; }
.btn-info { background: #2980b9; color: #fff; }
.btn:disabled { background: #ccc; cursor: not-allowed; }
.btn-sm { padding: 4px 10px; font-size: 0.8rem; }

.form-group { margin-bottom: 14px; }
.form-group label { display: block; font-weight: 600; margin-bottom: 4px; font-size: 0.88rem; }
.form-group input[type=text],
.form-group input[type=number],
.form-group input[type=password],
.form-group input[type=tel],
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.9rem;
  font-family: inherit;
}
.form-group .checkbox-inline { display: flex; align-items: center; gap: 6px; font-weight: normal; }
.form-row { display: flex; gap: 16px; flex-wrap: wrap; }
.form-row .form-group { flex: 1; min-width: 160px; }

table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
th, td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); }
th { background: #f5f7f8; font-weight: 600; }
tr:hover td { background: #f9fbfc; }

.badge { padding: 2px 8px; border-radius: 10px; font-size: 0.78rem; font-weight: 600; }
.badge-success { background: #e8f8f0; color: var(--success); }
.badge-warning { background: #fdf2e3; color: var(--warning); }
.badge-error { background: #fdecea; color: var(--error); }
.badge-info { background: #eaf3fb; color: #2980b9; }
.badge-muted { background: #eee; color: #777; }

.alert { padding: 10px 14px; border-radius: 6px; margin-bottom: 16px; font-size: 0.9rem; }
.alert-success { background: #e8f8f0; color: #1e824c; border: 1px solid #b7e4c7; }
.alert-error { background: #fdecea; color: #b03a2e; border: 1px solid #f5b7b1; }

.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 16px; }
.stat-tile { background: #fff; border: 1px solid var(--border); border-radius: 8px; padding: 16px; }
.stat-tile .value { font-size: 1.6rem; font-weight: 700; color: var(--secondary); }
.stat-tile .label { font-size: 0.82rem; color: #7f8c8d; }

.modal-overlay {
  display: none;
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.45);
  align-items: center; justify-content: center;
  z-index: 100;
}
.modal-overlay.open { display: flex; }
.modal {
  background: #fff; border-radius: 8px; padding: 20px;
  width: 90%; max-width: 480px; max-height: 90vh; overflow-y: auto;
}
.modal-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
.modal-close { background: none; border: none; font-size: 1.2rem; cursor: pointer; }

.login-page {
  min-height: 100vh; display: flex; align-items: center; justify-content: center; background: var(--secondary);
}
.login-card { background: #fff; padding: 32px; border-radius: 8px; width: 320px; }
.login-card h1 { font-size: 1.2rem; text-align: center; margin-bottom: 20px; }

.preview-box { border: 1px dashed var(--border); border-radius: 8px; padding: 16px; background: #fafcfd; }

@media (max-width: 768px) {
  .admin-shell { flex-direction: column; }
  .sidebar { width: 100%; }
  .sidebar nav { flex-direction: row; overflow-x: auto; }
}