(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:
.dropdown__menu position: absolute; top: 100%; left: 0; min-width: 160px; margin: 0; padding: 0.5rem 0; background: white; border-radius: 8px; box-shadow: 0 8px 20px rgba(0,0,0,0.15); list-style: none; opacity: 0; visibility: hidden; transform: translateY(-10px); transition: opacity 0.2s ease, visibility 0.2s, transform 0.2s ease; z-index: 1000; dropdown css
.dropdown__menu li a display: block; padding: 0.5rem 1rem; color: #1e293b; text-decoration: none; transition: background 0.15s; (JavaScript can toggle data-open ; CSS-only arrow change
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. (JavaScript can toggle data-open