Function handleModalKeydown

website/src/scripts/modal.ts:491–513

* Handle keyboard navigation within modal (focus trap)

(e: KeyboardEvent, modal: HTMLElement)

 * Handle keyboard navigation within modal (focus trap)
 */
function handleModalKeydown(e: KeyboardEvent, modal: HTMLElement): void {
  if (e.key === "Tab") {
    const focusableElements = getFocusableElements(modal);
    if (focusableElements.length === 0) return;

    const firstElement = focusableElements[0];
    const lastElement = focusableElements[focusableElements.length - 1];

    if (e.shiftKey) {
      // Shift+Tab: if on first element, wrap to last
      if (document.activeElement === firstElement) {
        e.preventDefault();
        lastElement.focus();
      }
    } else {
      // Tab: if on last element, wrap to first
      if (document.activeElement === lastElement) {
        e.preventDefault();
        firstElement.focus();
      }
    }
  }
}

/**
 * Setup modal functionality