/*
 * Buttons
 * <button class="btn btn--primary">Save</button>
 * Variants: --primary, --secondary, --ghost, --danger, --danger-ghost
 * Sizes:    --sm, --lg     Modifiers: --block (full width), --icon (square)
 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  height: var(--control-height-md);
  padding: 0 var(--space-4);
  border: var(--border-width) solid transparent;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  line-height: var(--leading-none);
  white-space: nowrap;
  text-decoration: none;
  cursor: pointer;
  user-select: none;
  transition:
    background-color var(--duration-fast) var(--ease-out),
    border-color var(--duration-fast) var(--ease-out),
    color var(--duration-fast) var(--ease-out),
    box-shadow var(--duration-fast) var(--ease-out);

  &:hover {
    text-decoration: none;
  }

  &:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
  }

  &:disabled,
  &[aria-disabled="true"] {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
  }

  svg {
    width: var(--icon-sm);
    height: var(--icon-sm);
    flex-shrink: 0;
  }
}

.btn--primary {
  background: var(--color-primary);
  color: var(--color-on-primary);
  box-shadow: var(--shadow-xs);

  &:hover { background: var(--color-primary-hover); color: var(--color-on-primary); }
  &:active { background: var(--color-primary-active); }
}

.btn--secondary {
  background: var(--color-surface);
  border-color: var(--color-border-strong);
  color: var(--color-text);
  box-shadow: var(--shadow-xs);

  &:hover { background: var(--color-surface-hover); color: var(--color-text); }
  &:active { background: var(--color-surface-active); }
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-muted);

  &:hover { background: var(--color-surface-hover); color: var(--color-text); }
}

/* Opt-in underline on hover, for buttons that read as links (e.g. inside a table row).
   .btn turns text-decoration off on hover; this comes later, so it wins */
.btn--underline-hover:hover {
  text-decoration: underline;
}

.btn--danger {
  background: var(--color-danger);
  color: var(--white);

  &:hover { background: var(--color-danger-hover); color: var(--white); }
}

.btn--danger-ghost {
  background: transparent;
  color: var(--color-danger-text);

  &:hover { background: var(--color-danger-subtle); color: var(--color-danger-text); }
}

.btn--sm {
  height: var(--control-height-sm);
  padding: 0 var(--space-3);
  font-size: var(--text-xs);
}

.btn--lg {
  height: var(--control-height-lg);
  padding: 0 var(--space-5);
  font-size: var(--text-md);
}

.btn--block {
  width: 100%;
}

/* Square, icon-only button — always give it an aria-label */
.btn--icon {
  padding: 0;
  aspect-ratio: 1;
}

/* button_to wraps the button in a <form>; keep it from breaking layouts */
form.button_to {
  display: inline-flex;
}