Css | Dropdown

(JavaScript can toggle data-open ; CSS-only arrow change requires :focus-within plus sibling selectors — omitted for brevity.) For mobile, convert absolute positioning to full-width block:

Abstract Dropdown menus remain a critical UI component for navigation and form inputs. This paper presents a CSS-only approach to building accessible, responsive, and visually consistent dropdowns without JavaScript, leveraging pseudo-classes, transitions, and the :focus-within selector. 1. HTML Structure A semantic foundation ensures accessibility and styling hooks. dropdown css

.dropdown__trigger:focus-visible outline: 2px solid #3b82f6; outline-offset: 2px; (JavaScript can toggle data-open ; CSS-only arrow change

:focus-within keeps the dropdown open when tabbing into menu items, enabling full keyboard accessibility. 4. Arrow Rotation & State .dropdown[data-open="true"] .dropdown__arrow transform: rotate(180deg); Arrow Rotation & State

.dropdown__menu li a display: block; padding: 0.5rem 1rem; color: #1e293b; text-decoration: none; transition: background 0.15s;

.dropdown__menu li a:hover, .dropdown__menu li a:focus-visible background-color: #f1f5f9; outline: none;