Stow: use font-base for buttons

stow/sass/style-child-theme-editor.scss

@@ -164,6 +164,7 @@ a {
 		cursor: pointer;
 		font-weight: #{map-deep-get($config-button, "font", "weight")};
 		font-family: #{map-deep-get($config-button, "font", "family")};
+		font-family: var( --font-base, #{map-deep-get($config-button, "font", "family")} );
 		font-size: #{map-deep-get($config-button, "font", "size")};
 		background-color: #{map-deep-get($config-button, "color", "background")};
 		border-radius: #{map-deep-get($config-button, "border-radius")};

stow/style-editor.css

@@ -1111,6 +1111,7 @@ a {
 	cursor: pointer;
 	font-weight: 600;
 	font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;
+	font-family: var(--font-base, -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif);
 	font-size: 0.69444rem;
 	background-color: #f25f70;
 	border-radius: 9px;