woocommerce/plugins/woocommerce-blocks/packages/components/radio-control/style.scss

.wc-block-components-radio-control--highlight-checked {
	position: relative;

	div.wc-block-components-radio-control-accordion-option {
		position: relative;

		// This ::after element is to fake a transparent border-top on each option.
		// We can't just use border-top on the option itself because of the border around the entire accordion.
		// Both borders have transparency so there's an overlap where the border is darker (due to adding two
		// transparent colours together). Doing it with an ::after lets us bring the "border" in by one pixel on each
		// side to avoid the overlap.
		&::after {
			content: "";
			background: $universal-border-light;
			height: 1px;
			right: 1px;
			left: 1px;
			top: 0;
			position: absolute;
		}

		// The first child doesn't need a fake border-top because it's handled by its parent's border-top. This stops
		// a double border.
		&:first-child::after {
			display: none;
		}

		// This rule removes the fake border-top from the selected element to prevent a double border.
		&.wc-block-components-radio-control-accordion-option--checked-option-highlighted + div.wc-block-components-radio-control-accordion-option::after {
			display: none;
		}
	}

	// Adds a "border" around the selected option. This is done with a box-shadow to prevent a double border on the left
	// and right of the selected element, and top and bottom of the first/last elements.
	label.wc-block-components-radio-control__option--checked-option-highlighted,
	.wc-block-components-radio-control-accordion-option--checked-option-highlighted {
		box-shadow: 0 0 0 2px currentColor inset;
		border-radius: 4px;
	}

	// Defines a border around the radio control. Cannot be done with normal CSS borders or outlines because when
	// selecting an item we get a double border on the left and right. It's not possible to remove the outer border just
	// for the selected element, but using a pseudo element gives us more control.
	&::after {
		content: "";
		top: 0;
		right: 0;
		bottom: 0;
		left: 0;
		pointer-events: none;
		position: absolute;
		border: 1px solid $universal-border-light;
		border-radius: 4px;
		width: 100%;
		box-sizing: border-box;
	}

	// Remove the top border when the first element is selected, this is so we don't get a double border with the
	// box-shadow.
	&.wc-block-components-radio-control--highlight-checked--first-selected::after {
		border-top: 0;
		margin-top: 2px;
	}

	// Remove the bottom border when the last element is selected, this is so we don't get a double border with the
	// box-shadow.
	&.wc-block-components-radio-control--highlight-checked--last-selected::after {
		margin-bottom: 2px;
		border-bottom: 0;
	}

	// Remove the fake border-top from the item after the selected element, this is to prevent a double border with the
	// selected element's box-shadow.
	.wc-block-components-radio-control__option--checked-option-highlighted + .wc-block-components-radio-control__option::after {
		display: none;
	}

	.wc-block-components-radio-control__option {

		// Add a fake border to the top of each radio option. This is because using CSS borders would result in an
		// overlap and two transparent borders combining to make a darker pixel. This fake border allows us to bring the
		// border in by one pixel on each side to avoid the overlap.
		&::after {
			content: "";
			background: $universal-border-light;
			height: 1px;
			right: 1px;
			left: 1px;
			top: 0;
			position: absolute;
		}

		// The first child doesn't need a fake border-top because it's handled by its parent's border-top.
		&:first-child::after {
			display: none;
		}
	}
}

.wc-block-components-radio-control__option {
	@include reset-color();
	@include reset-typography();
	display: block;
	margin: em($gap) 0;
	margin-top: 0;
	padding: 0 0 0 em($gap-larger);
	position: relative;
	cursor: pointer;

	&:last-child {
		margin-bottom: 0;
	}
}

.wc-block-components-radio-control__option-layout {
	display: table;
	width: 100%;
}

.wc-block-components-radio-control__option
.wc-block-components-radio-control__option-layout {
	&::after {
		display: none;
	}
}

.wc-block-components-radio-control__label-group,
.wc-block-components-radio-control__description-group {
	display: table-row;

	> span {
		display: table-cell;
	}

	.wc-block-components-radio-control__secondary-label,
	.wc-block-components-radio-control__secondary-description {
		text-align: right;
		min-width: 50%;
	}
}

.wc-block-components-radio-control__label,
.wc-block-components-radio-control__secondary-label {
	// Currently, max() CSS function calls need to be wrapped with unquote.
	// See: https://github.com/sass/sass/issues/2378#issuecomment-367490840
	// These values should be the same as the control input height.
	line-height: string.unquote("max(1.5rem, 24px)");
}

.wc-block-components-radio-control__description,
.wc-block-components-radio-control__secondary-description {
	@include font-size(small);
	line-height: 1.55;
}

// Extra class for specificity.
.wc-block-components-radio-control {
	.wc-block-components-radio-control__input {
		appearance: none;
		background: #fff;
		border: 1px solid $universal-border-medium;
		border-radius: 50%;
		color: currentColor;
		display: inline-block;
		height: em(24px); // =1.5rem
		min-height: 24px;
		min-width: 24px;
		width: em(24px);
		// The code belows centers the input vertically.
		position: absolute;
		left: $gap;
		top: 50%;
		transform: translate(0, -45%);
		margin: inherit;
		cursor: pointer;
		&:checked {
			border: 1px solid currentColor;
		}

		&:focus {
			outline: 2px solid currentColor;
			outline-offset: 2px;
		}

		&:checked::before {
			background: currentColor;
			border-radius: 50%;
			content: "";
			display: block;
			height: em(12px);
			left: 50%;
			margin: 0;
			min-height: 12px;
			min-width: 12px;
			position: absolute;
			top: 50%;
			transform: translate(-50%, -50%);
			width: em(12px);
		}

		.has-dark-controls & {
			border-color: $controls-border-dark;
			background-color: $input-background-dark;

			&:checked::before {
				background: $input-text-dark;
			}
		}

		&[aria-disabled="true"],
		&[disabled] {
			cursor: not-allowed;
			opacity: 0.5;
			transition: opacity 200ms ease;
		}
	}
}

.theme-twentytwentyone {
	.wc-block-components-radio-control
	.wc-block-components-radio-control__input {
		&:checked {
			border-width: 2px;

			&::before {
				background-color: var(--form--color-text);
			}
		}

		&::after {
			display: none;
		}
	}
}