:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --text-main: #1f2937;
  --text-muted: #4b5563;
  --text-light: #9ca3af;
  --bg-page: #f8fafc;
  --bg-card: #ffffff;
  --border-color: #e5e7eb;
  --border-hover: #3b82f6;
  --danger-bg: #fee2e2;
  --danger-text: #dc2626;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-page);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

.fade-in {
  animation: fadeIn 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid rgba(37, 99, 235, 0.15);
  border-left-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.checkerboard {
  background-color: #ffffff;
  background-image: 
    linear-gradient(45deg, #f1f5f9 25%, transparent 25%),
    linear-gradient(-45deg, #f1f5f9 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #f1f5f9 75%),
    linear-gradient(-45deg, transparent 75%, #f1f5f9 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
}

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.25);
  }
}