Minor CSS changes

Author: pikinier20

scaladoc/resources/dotty_res/styles/colors.css

@@ -75,7 +75,7 @@
   --leftbar-current-fg: var(--blue500);
   --leftbar-hover-bg: var(--blue100);
   --leftbar-hover-fg: var(--grey900);
-  --leftbar-border: var(--grey200);
+  --leftbar-border: var(--grey300);
 
   --footer-bg: var(--white);
   --footer-fg: var(--grey700);

scaladoc/resources/dotty_res/styles/scalastyle.css

@@ -247,6 +247,10 @@ th {
   box-sizing: border-box;
 }
 
+#sideMenu2 a:hover {
+  color: var(--link-hover-fg);
+}
+
 #sideMenu2 a span:not(.micon) {
   margin-right: 0.75ex;
   text-indent: -1.5em;
@@ -274,7 +278,7 @@ span.ar {
 }
 
 span.ar::before {
-  content: "\e903"; /* arrow down */
+  content: "\e904"; /* arrow right */
   font-family: "dotty-icons" !important;
   font-size: 20px;
   color: var(--icon-color);
@@ -283,8 +287,8 @@ span.ar::before {
   align-items: center;
   justify-content: center;
 }
-.expanded>span.ar::before {
-  content: "\e905"; /* arrow up */
+.nav-item.expanded > .nav-header > span.ar::before {
+  content: "\e903"; /* arrow down */
 }
 
 .div:hover>span.ar::before {
@@ -599,7 +603,7 @@ footer .mode {
 
 .documentableElement .signature {
   color: var(--code-fg);
-  display: table-cell;
+  display: table-row;
   white-space: pre-wrap;
 }
 
@@ -623,7 +627,7 @@ footer .mode {
 }
 
 .expand .signature {
-  display: table-cell;
+  display: table-row;
 }
 
 .documentableFilter {
@@ -685,10 +689,23 @@ footer .mode {
   display: none;
 }
 
+.documentableElement:before {
+  content: ' ';
+  position: absolute;
+  width: 32px;
+  height: 100%;
+  top: 0px;
+  left: -32px;
+}
+
 .documentableElement:hover .documentableAnchor:before {
   display: flex;
 }
 
+.documentableElement::before:hover .documentableAnchor:before {
+  display: flex;
+}
+
 .documentableAnchor:before {
   content: "\e901"; /* arrow down */
   font-family: "dotty-icons" !important;
@@ -701,7 +718,7 @@ footer .mode {
   justify-content: center;
   position: absolute;
   top: 6px;
-  margin-left: 0.2em;
+  left: -32px;
 }
 
 .memberDocumentation {