/* Spacing */
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }
.mb-2xl { margin-bottom: var(--space-2xl); }

/* Flexbox */
.flex { display: flex; }
.flex-between { display: flex; justify-content: space-between; align-items: center; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-gap-sm { gap: var(--space-sm); }
.flex-gap-md { gap: var(--space-md); }
.flex-wrap { flex-wrap: wrap; }

/* Grid */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-md); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-md); }

@media (max-width: 768px) {
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
}

/* Text */
.text-right { text-align: right; }
.text-center { text-align: center; }
.font-mono { font-family: var(--font-mono); }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* Visibility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.hidden { display: none !important; }

/* Action button groups (tables, cards) */
.btn-group {
  display: flex;
  gap: var(--space-xs);
  flex-wrap: wrap;
}

/* Skip to content */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  z-index: var(--z-overlay);
  padding: var(--space-sm) var(--space-md);
  background: var(--accent);
  color: var(--bg);
  border-radius: var(--radius-md);
  font-weight: var(--font-semibold);
}

.skip-link:focus {
  top: var(--space-md);
}