NodeBB/public/scss/modules/bottom-sheet.scss

.bottom-sheet {
	@include media-breakpoint-down(md) {
		.dropdown-menu {
			display: block;
			visibility: hidden;

			position: fixed!important;
			inset: auto 0 0 0!important;

			margin: 0 -1px -1px -1px;
			padding: $spacer * 0.25 !important;
			max-height: 60%;

			box-shadow: 0 2px 6px rgba(0,0,0,0.35);
			overflow: auto;
			-webkit-overflow-scrolling: touch;
			transform: translate3d(0, 350px, 0);
			transition: transform 0.3s, visibility 0s 0.3s;
			z-index: $zindex-popover;
			padding: 5px 0 10px;

			border-radius: 0;
			border: 0px;
			border-top: 1px solid $border-color;

			> li {
				> a, .dropdown-item {
					padding: 10px 20px;
					overflow: hidden;
					text-overflow: ellipsis;
					white-space: nowrap;
				}

				&.divider {
					padding: 0;
				}
			}
		}

		.dropdown-menu.show {
			transform: none!important;
			visibility: visible;
			transition-delay: 0s;
			top: auto;
			width: auto;
		}

		.dropdown-backdrop {
			background-color: rgba(0, 0, 0, .3);
		}
	}
}