fix(ui): broken sidebar, table of content and header on linux (#315)

* move squircle to only to active and hover states

* fix hover

* fix squircle in header

* fix toc

* rm redundant line

src/frontend/styles/components/header.pcss

@@ -40,7 +40,10 @@ html {
 
     @media (--not-mobile) {
       padding: 4px 10px;
-      @apply --squircle;
+
+      &:hover {
+        @apply --squircle;
+      }
     }
 
     &:hover {

src/frontend/styles/components/sidebar.pcss

@@ -182,13 +182,16 @@
     transition-property: background-color;
     transition-duration: 0.1s;
 
-    @apply --squircle;
-
     &--selected {
       border-radius: 8px;
       /* border using box-shadow which doesn't increase the height */
       box-shadow: 0 0 0 2px rgba(147, 166, 233, 0.5) inset;
     }
+
+    &--active,
+    &:hover {
+      @apply --squircle;
+    }
   }
 
   &__section-title > span,

src/frontend/styles/components/table-of-content.pcss

@@ -31,7 +31,10 @@
     gap: 2px;
 
     &-item {
-      @apply --squircle;
+      &:hover,
+      &--active {
+        @apply --squircle;
+      }
 
       &:hover {
         background-color: var(--color-link-hover);