Fix compat issue.

_sass/base/_typography.scss

@@ -138,7 +138,7 @@
 		border-left: solid 3px _palette(border);
 		font-style: italic;
 		margin: 0 0 _size(element-margin) 0;
-		padding: math.div(_size(element-margin), 4) 0 math.div(_size(element-margin), 4) _size(element-margin);
+		padding: calc(_size(element-margin) / 4) 0 calc(_size(element-margin) / 4) _size(element-margin);
 	}
 
 	code {

_sass/components/_list.scss

@@ -83,7 +83,7 @@
 					line-height: 1.125em;
 					position: absolute;
 					text-align: center;
-					top: math.div(1.5em, 1.5);
+					top: clac(1.5em / 1.5);
 					width: 1.5em;
 				}
 

_sass/layout/_header.scss

@@ -41,10 +41,10 @@
 			}
 
 			.icons {
-				height: math.div(6.25em, 1.25);
-				line-height: math.div(6.25em, 1.25);
+				height: calc(6.25em / 1.25);
+				line-height: calc(6.25em / 1.25);
 				position: absolute;
-				right: math.div(-0.625em,  1.25);
+				right: calc(-0.625em / 1.25);
 				top: 0;
 			}
 		}

_sass/layout/_sidebar.scss

@@ -18,14 +18,14 @@
 				cursor: default;
 				display: block;
 				font-size: 1.5em;
-				height: math.div(_size(element-height), 1.375);
-				line-height: math.div(_size(element-height), 1.375);
+				height: calc(_size(element-height) / 1.375);
+				line-height: calc(_size(element-height) / 1.375);
 				opacity: 0.325;
 				position: absolute;
 				right: 0;
 				text-align: center;
 				top: 0;
-				width: math.div(_size(element-height), 1.375);
+				width: calc(_size(element-height) / 1.375);
 			}
 
 			input[type="text"] {
@@ -35,7 +35,7 @@
 	}
 
 	#sidebar {
-		$pad: math.div(2em, 0.9);
+		$pad: calc(2em / 0.9);
 
 		@include vendor('flex-grow', '0');
 		@include vendor('flex-shrink', '0');
@@ -49,7 +49,7 @@
 		width: _size(sidebar-width);
 
 		h2 {
-			font-size: math.div(1.25em, 0.9);
+			font-size: calc(1.25em / 0.9);
 		}
 
 		> .inner {
@@ -118,7 +118,7 @@
 		}
 
 		@include breakpoint(xlarge) {
-			$pad: math.div(1.5em, 0.9);
+			$pad: calc(1.5em / 0.9);
 
 			width: _size(sidebar-width-alt);
 
@@ -185,7 +185,7 @@
 
 				&:before {
 					font-size: 1.5rem;
-					margin-left: math.div(-0.875em, 2);
+					margin-left: clac(-0.875em / 2);
 				}
 			}
 
@@ -201,8 +201,8 @@
 
 				&:before {
 					color: _palette(fg);
-					margin-left: math.div(-0.125em, 2);
-					margin-top: math.div(-0.5em, 2);
+					margin-left: clac(-0.125em / 2);
+					margin-top: clac(-0.5em / 2);
 					font-size: 1.1rem;
 					z-index: 1;
 				}

_sass/main_style.scss

@@ -1,4 +1,3 @@
-@use 'sass:math';
 @import 'libs/vars';
 @import 'libs/functions';
 @import 'libs/mixins';