:root {
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --primary-light: #e0e7ff;
  --secondary: #ec4899;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --bg: #f8fafc;
  --bg-card: #ffffff;
  --bg-sidebar: #ffffff;
  --text: #1e293b;
  --text-muted: #64748b;
  --text-light: #94a3b8;
  --border: #e2e8f0;
  --border-light: #f1f5f9;
  --shadow: 0 1px 3px rgba(0,0,0,.08),0 1px 2px rgba(0,0,0,.06);
  --shadow-md: 0 4px 6px rgba(0,0,0,.07),0 2px 4px rgba(0,0,0,.06);
  --shadow-lg: 0 10px 15px rgba(0,0,0,.1),0 4px 6px rgba(0,0,0,.05);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-lg: 16px;
  --transition: 0.2s ease;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', sans-serif;
  --nav-height: 60px;
  --sidebar-width: 260px;
}

[data-theme="dark"] {
  --bg: #0f172a;
  --bg-card: #1e293b;
  --bg-sidebar: #1e293b;
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --text-light: #64748b;
  --border: #334155;
  --border-light: #1e293b;
  --shadow: 0 1px 3px rgba(0,0,0,.3);
  --shadow-md: 0 4px 6px rgba(0,0,0,.3);
  --shadow-lg: 0 10px 15px rgba(0,0,0,.4);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  transition: background var(--transition), color var(--transition);
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }
img { max-width: 100%; height: auto; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 16px; }
.container-sm { max-width: 720px; margin: 0 auto; padding: 0 16px; }

/* Cards */
.card {
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  overflow: hidden;
}
.card-body { padding: 20px; }
.card-header { padding: 16px 20px; border-bottom: 1px solid var(--border); font-weight: 600; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  line-height: 1;
}
.btn:disabled { opacity: .6; cursor: not-allowed; }
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); color: #fff; }
.btn-secondary { background: var(--border); color: var(--text); }
.btn-secondary:hover { background: var(--border-light); }
.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { background: #dc2626; color: #fff; }
.btn-success { background: var(--success); color: #fff; }
.btn-outline { background: transparent; border: 1.5px solid var(--primary); color: var(--primary); }
.btn-outline:hover { background: var(--primary); color: #fff; }
.btn-sm { padding: 6px 14px; font-size: 13px; }
.btn-lg { padding: 14px 28px; font-size: 16px; }
.btn-block { width: 100%; justify-content: center; }
.btn-icon { padding: 8px; border-radius: 8px; }

/* Forms */
.form-group { margin-bottom: 16px; }
.form-label { display: block; font-size: 13px; font-weight: 600; color: var(--text-muted); margin-bottom: 6px; }
.form-control {
  width: 100%;
  padding: 11px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text);
  background: var(--bg-card);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.form-control:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(99,102,241,.15); }
.form-control::placeholder { color: var(--text-light); }
.form-control-lg { padding: 14px 16px; font-size: 16px; }
select.form-control { cursor: pointer; }
textarea.form-control { resize: vertical; min-height: 100px; }
.form-hint { font-size: 12px; color: var(--text-muted); margin-top: 4px; }
.form-error { font-size: 12px; color: var(--danger); margin-top: 4px; }
.input-group { display: flex; }
.input-group .form-control { border-radius: var(--radius-sm) 0 0 var(--radius-sm); border-right: none; }
.input-group .btn { border-radius: 0 var(--radius-sm) var(--radius-sm) 0; }

/* Alerts */
.alert { padding: 12px 16px; border-radius: var(--radius-sm); margin-bottom: 16px; font-size: 14px; display: flex; align-items: flex-start; gap: 10px; }
.alert-danger { background: #fef2f2; color: #991b1b; border: 1px solid #fecaca; }
.alert-success { background: #f0fdf4; color: #166534; border: 1px solid #bbf7d0; }
.alert-warning { background: #fffbeb; color: #92400e; border: 1px solid #fde68a; }
.alert-info { background: #eff6ff; color: #1e40af; border: 1px solid #bfdbfe; }
[data-theme="dark"] .alert-danger { background: #450a0a; color: #fca5a5; border-color: #7f1d1d; }
[data-theme="dark"] .alert-success { background: #052e16; color: #86efac; border-color: #14532d; }

/* Badges */
.badge { display: inline-flex; align-items: center; padding: 3px 8px; border-radius: 20px; font-size: 11px; font-weight: 700; }
.badge-primary { background: var(--primary-light); color: var(--primary-dark); }
.badge-success { background: #d1fae5; color: #065f46; }
.badge-danger { background: #fee2e2; color: #991b1b; }
.badge-warning { background: #fef3c7; color: #92400e; }
.badge-muted { background: var(--border); color: var(--text-muted); }
[data-theme="dark"] .badge-success { background: #064e3b; color: #6ee7b7; }
[data-theme="dark"] .badge-danger { background: #450a0a; color: #fca5a5; }

/* Avatar */
.avatar {
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
  background: var(--primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--primary);
}
.avatar-sm { width: 32px; height: 32px; font-size: 13px; }
.avatar-md { width: 44px; height: 44px; font-size: 16px; }
.avatar-lg { width: 80px; height: 80px; font-size: 28px; }
.avatar-xl { width: 120px; height: 120px; font-size: 40px; }

/* Grid */
.grid { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* Utilities */
.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-gap { display: flex; align-items: center; gap: 10px; }
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.text-small { font-size: 13px; }
.mt-1 { margin-top: 8px; } .mt-2 { margin-top: 16px; } .mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; } .mb-2 { margin-bottom: 16px; } .mb-3 { margin-bottom: 24px; }
.p-2 { padding: 16px; } .p-3 { padding: 24px; }
.w-100 { width: 100%; }
.hidden { display: none !important; }
.divider { border: none; border-top: 1px solid var(--border); margin: 20px 0; }

/* Theme toggle */
.theme-toggle {
  width: 44px; height: 24px;
  background: var(--border);
  border-radius: 12px;
  border: none;
  cursor: pointer;
  position: relative;
  transition: background var(--transition);
}
.theme-toggle::after {
  content: '';
  position: absolute;
  width: 18px; height: 18px;
  background: #fff;
  border-radius: 50%;
  top: 3px; left: 3px;
  transition: transform var(--transition);
  box-shadow: var(--shadow);
}
[data-theme="dark"] .theme-toggle { background: var(--primary); }
[data-theme="dark"] .theme-toggle::after { transform: translateX(20px); }

/* Loading spinner */
.spinner {
  width: 20px; height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Skeleton */
.skeleton { background: linear-gradient(90deg, var(--border) 25%, var(--border-light) 50%, var(--border) 75%); background-size: 200% 100%; animation: shimmer 1.5s infinite; border-radius: 6px; }
@keyframes shimmer { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

/* Tables */
.table-wrapper { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--border); }
table { width: 100%; border-collapse: collapse; }
thead th { padding: 12px 16px; text-align: left; font-size: 12px; font-weight: 700; color: var(--text-muted); text-transform: uppercase; letter-spacing: .05em; background: var(--bg); border-bottom: 1px solid var(--border); }
tbody td { padding: 12px 16px; font-size: 14px; border-bottom: 1px solid var(--border-light); vertical-align: middle; }
tbody tr:last-child td { border-bottom: none; }
tbody tr:hover { background: var(--border-light); }

/* Post cards */
.post-card { border-radius: var(--radius); overflow: hidden; background: var(--bg-card); box-shadow: var(--shadow); border: 1px solid var(--border); transition: box-shadow var(--transition), transform var(--transition); }
.post-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-2px); }
.post-card-cover { width: 100%; height: 200px; object-fit: cover; }
.post-card-body { padding: 16px; }
.post-card-title { font-size: 17px; font-weight: 700; color: var(--text); margin-bottom: 8px; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.post-card-excerpt { font-size: 14px; color: var(--text-muted); display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.post-card-meta { display: flex; align-items: center; gap: 12px; margin-top: 12px; font-size: 13px; color: var(--text-light); }
.post-card-actions { display: flex; gap: 8px; align-items: center; margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--border-light); }

/* Modals */
.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,.5); z-index: 1000; display: flex; align-items: center; justify-content: center; padding: 16px; backdrop-filter: blur(4px); }
.modal { background: var(--bg-card); border-radius: var(--radius-lg); width: 100%; max-width: 500px; max-height: 90vh; overflow: auto; box-shadow: var(--shadow-lg); animation: modalIn .2s ease; }
@keyframes modalIn { from { transform: scale(.95); opacity: 0; } to { transform: scale(1); opacity: 1; } }
.modal-header { padding: 20px 24px; border-bottom: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; font-weight: 700; font-size: 18px; }
.modal-body { padding: 24px; }
.modal-footer { padding: 16px 24px; border-top: 1px solid var(--border); display: flex; gap: 10px; justify-content: flex-end; }

/* Toast */
.toast-container { position: fixed; bottom: 24px; right: 24px; z-index: 2000; display: flex; flex-direction: column; gap: 8px; }
.toast { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 12px 16px; font-size: 14px; box-shadow: var(--shadow-lg); display: flex; align-items: center; gap: 10px; min-width: 260px; animation: toastIn .3s ease; }
.toast.success { border-left: 4px solid var(--success); }
.toast.error { border-left: 4px solid var(--danger); }
@keyframes toastIn { from { transform: translateX(100%); opacity: 0; } to { transform: translateX(0); opacity: 1; } }

/* Responsive */
@media (max-width: 768px) {
  .grid-3, .grid-4 { grid-template-columns: 1fr 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
  .hide-mobile { display: none !important; }
}
@media (max-width: 480px) {
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
  .modal { border-radius: var(--radius) var(--radius) 0 0; align-self: flex-end; max-height: 85vh; }
  .modal-overlay { align-items: flex-end; padding: 0; }
  .toast-container { bottom: 80px; right: 12px; left: 12px; }
  .toast { min-width: auto; }
}