zotero/scss/components/_tabsMenu.scss

#zotero-tabs-menu-panel::part(content) {
	padding: 0;
	margin: 0;
}

#zotero-tabs-menu-wrapper {
	width: 350px;
	background: var(--material-sidepane);
	padding: 7px;
	border-radius: 5px;
	--width-focus-border: 2px;
}

#zotero-tabs-menu-filter {
	margin: 0 0 7px 0;
	border-radius: 5px;
	border: 1px solid transparent;
	padding-inline-start: 5px !important;
	padding: 2px;

	@media not (-moz-platform: windows) {
		@include focus-ring;
	}
}

#zotero-tabs-menu-list {
	appearance: none;
	margin: 0;

	.row {
		display: flex;
		padding-inline-start: 4px;
	}

	.zotero-tabs-menu-entry {
		@include focus-ring;
		border-radius: 6px;
		height: 22px;
		margin: 0;
		&.close {
			width: 22px;
			// Center the icon within the larger box
			display: flex;
			justify-content: center;
			align-items: center;
			&[hidden] {
				visibility: hidden;
			}
		}
		&.title {
			padding: 0;
			padding-inline-start: 6px;
			color: unset;
			// Align label with the icon
			display: flex;
			align-items: center;
			width: 100%;
			&.selected {
				font-weight: 600;
			}
			label {
				overflow: hidden;
				// override default description margins
				margin-bottom: 0;
				margin-block-start: 0;
				// show as much of the description as possible
				white-space: nowrap;
				min-width: 280px;
				text-overflow: ellipsis;
				// Fx115: make label have the right width
				max-width: 280px;
				display: inline-block;
			}
			.tab-icon {
				width: 16px;
				height: 16px;
				margin-inline-end: 4px;
			}
		}
		
		&:hover {
			background-color: var(--fill-quinary) !important;
		}
		&:active {
			background-color: var(--fill-quarternary) !important;
		}
	}
	#zotero-tabs-menu-dragged {
		opacity: 0;
	}	
}