/**
 * PinnableElement
 * Pinned containers are typically dropdown menus that have been
 * placed in a sidebar column, e.g. page tools menu, main menu.
 */

.vector-pinnable-element {
	font-size: @font-size-dropdown;
}

.vector-pinned-container {
	.mixin-vector-content-box();
	padding: @padding-vertical-dropdown-menu @padding-horizontal-dropdown-menu;
	margin-bottom: @grid-column-gap;
}

// Applies styles for making a pinned element sticky
// Mixin should be applied to the container element of `.vector-pinned-container`;
.vector-sticky-pinned-container {
	height: 100%;

	.vector-pinned-container {
		// stylelint-disable-next-line plugin/no-unsupported-browser-features
		position: sticky;
		top: @grid-row-gap;
	}

	.vector-pinnable-element {
		max-height: ~'calc( 100vh - @{grid-row-gap} - @{padding-vertical-dropdown-menu} - @{padding-vertical-dropdown-menu} - @{grid-row-gap} )';
		overflow-y: auto;

		&::after {
			content: '';
			display: block;
			position: absolute;
			// Offset position to account for menu borders.
			bottom: @border-width-base;
			// Offset to account for border radius.
			left: @border-radius-content-box;
			right: @border-radius-content-box;
			height: @height-scroll-indicator;
			background: linear-gradient( rgba( 255, 255, 255, 0 ), @background-color-page-container );
			background-repeat: no-repeat;
			background-position: -12px; // T311436 Hacky way to prevent the fade from covering the scrollbar
			pointer-events: none; // Make the link below the fade clickable
		}
	}
}

/**
 * At lower resolutions, we want to hide the pinned containers when JS is enabled since these
 * elements collapse (become unpinned) at this resolution via PinnableElement.js.
 * Although this is handled in JS, this rule prevents the pinned menu from
 * appearing on pageload, at low resolutions, before the JS kicks in.
 *
 * When JS is disabled, we still want to hide the pinned containers at lower resolutions
 * to fallback to the gradeC, single column layout.
 */
@media ( max-width: @max-width-tablet ) {
	// .client-js and .client-nojs selectors needed to increase specificity to override gradeC.less
	// Prefered to using !important as this still needs to be overridable to handle
	// the anon, no-js TOC case found in layouts/toc/unpinned.less
	&.client-js,
	&.client-nojs {
		.vector-pinned-container {
			display: none;
		}
	}
}