:root {
  --bg: #f1f5f9;
  --surface: #ffffff;
  --surface-hover: #f8fafc;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --text: #0f172a;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --primary: #2563eb;
  --primary-light: #eff6ff;
  --primary-dark: #1d4ed8;
  --success: #10b981;
  --success-bg: #f0fdf4;
  --success-border: #86efac;
  --warning: #f59e0b;
  --warning-bg: #fffbeb;
  --warning-border: #fcd34d;
  --danger: #ef4444;
  --danger-bg: #fef2f2;
  --danger-border: #fecaca;
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 16px;
  --shadow: 0 1px 3px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08);
}

* { margin:0; padding:0; box-sizing:border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes spin {
  to { transform: rotate(360deg); }
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}
@keyframes slideIn {
  from { transform: translateX(-100%); }
  to { transform: translateX(0); }
}

.animate-fade-in { animation: fadeIn 0.3s ease-out; }
.animate-pulse { animation: pulse 2s ease-in-out infinite; }

/* Utility */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.font-bold { font-weight: 700; }
.font-semibold { font-weight: 600; }
.text-sm { font-size: 13px; }
.text-xs { font-size: 12px; }
.text-lg { font-size: 16px; }
.text-xl { font-size: 20px; }
.text-2xl { font-size: 24px; }
.text-3xl { font-size: 32px; }
.mt-2 { margin-top: 8px; }
.mt-3 { margin-top: 12px; }
.mt-4 { margin-top: 16px; }
.mb-2 { margin-bottom: 8px; }
.mb-3 { margin-bottom: 12px; }
.mb-4 { margin-bottom: 16px; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.gap-4 { gap: 16px; }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.flex-1 { flex: 1; }
.w-full { width: 100%; }
.hidden { display: none !important; }

/* Responsive */
@media (max-width: 768px) {
  .hide-mobile { display: none !important; }
}
@media (min-width: 769px) {
  .hide-desktop { display: none !important; }
}