.dropdown:hover .dropdown__menu, .dropdown:focus-within .dropdown__menu, .dropdown__menu:hover opacity: 1; visibility: visible; transform: translateY(0);
: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); dropdown css
(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:hover opacity: 1
<div class="dropdown"> <button class="dropdown__trigger" aria-expanded="false" aria-haspopup="true"> Menu <span class="dropdown__arrow">▼</span> </button> <ul class="dropdown__menu" role="menu"> <li role="menuitem"><a href="#">Profile</a></li> <li role="menuitem"><a href="#">Settings</a></li> <li role="menuitem"><a href="#">Logout</a></li> </ul> </div> .dropdown position: relative; display: inline-block; (JavaScript can toggle data-open
.dropdown__menu li a:hover, .dropdown__menu li a:focus-visible background-color: #f1f5f9; outline: none;
.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;