mediawiki-skins-Citizen/resources/skins.citizen.styles/components/OverflowElements.less

@overflow-affordnance-size: 2rem;

.mask-gradient(@direction, @color1, @color2, @color3: null , @color4: null) {
	-webkit-mask-image: linear-gradient( @direction, @color1, @color2 );
	mask-image: linear-gradient( @direction, @color1, @color2 );

	& when not(@color3 = null), not(@color4 = null) {
		-webkit-mask-image: linear-gradient( @direction, @color1, @color2, @color3, @color4 );
		mask-image: linear-gradient( @direction, @color1, @color2, @color3, @color4 );
	}
}

// Elements enhanced by overflowElements.js
.citizen-overflow {
	&-wrapper {
		overflow-x: auto;

		.wikitable {
			display: table;
			max-width: none;
			overflow: initial;
		}
	}

	&--left {
		.mask-gradient(90deg, transparent, #000 @overflow-affordnance-size);
	}

	&--right {
		.mask-gradient(270deg, transparent, #000 @overflow-affordnance-size);
	}

	&--left&--right {
		.mask-gradient(90deg, transparent, #000 @overflow-affordnance-size, #000 ~'calc( 100% - @{overflow-affordnance-size} )', transparent);
	}
}