.semester {
	-webkit-flex: 1;
	flex: 1;

	padding: $block-edge-padding/2 $block-edge-padding;

	border-left: solid 1px #c4c4c4;

	-webkit-transition: 0.75s all;
	-moz-transition: 0.75s all;
	-ms-transition: 0.75s all;
	transition: 0.75s all;

	// &:hover, &:active, &:focus {
	// 	-webkit-flex: 1.1;
	// 	flex: 1.1;
	// }

	.semester-title {
		display: -webkit-flex;
		display: flex;
		-webkit-justify-content: space-between;
		justify-content: space-between;
	}

	&:hover {
		.remove-semester {
			display: inline-block;
		}
	}
}

.add-semester {
	@extend %add-button;
	border-left: solid 1px #c4c4c4;

	width: 32px;
	font-size: 1.25em;
}

.remove-semester {
	@extend %remove-button;
	display: none;

	border-radius: 50px;
}

$semester-divider: solid 1px $border-bottom-color;

.semester {
	-webkit-flex: 1;
	flex: 1;

	padding: $block-edge-padding/2 $block-edge-padding;

	border-left: $semester-divider;

	-webkit-transition: 0.75s all;
	-moz-transition: 0.75s all;
	-ms-transition: 0.75s all;
	transition: 0.75s all;

	// &:hover, &:active, &:focus {
	// 	-webkit-flex: 1.1;
	// 	flex: 1.1;
	// }

	.semester-title {
		display: -webkit-flex;
		display: flex;
		-webkit-justify-content: space-between;
		justify-content: space-between;
	}

	&:hover {
		.remove-semester {
			display: inline-block;
		}
	}
}

.add-semester {
	@extend %add-button;
	border-left: $semester-divider;

	width: 32px;
	font-size: 1.25em;
}

.remove-semester {
	@extend %remove-button;
	display: none;

	border-radius: 50px;
}

Use the new bottom-border color for the semester separation lines
Use the new bottom-border color for the semester separation lines
