refactor: uniform block border radius

scope:
- categories
- posts (prompt, code snippets)

_sass/layout/categories.scss

@@ -9,8 +9,14 @@
 .categories {
   margin-bottom: 2rem;
 
+  &.card,
+  .list-group {
+    @extend %rounded;
+  }
+
   .card-header {
     padding-right: 12px;
+    border-radius: $base-radius $base-radius 0 0;
   }
 
   i {
@@ -42,9 +48,7 @@
     position: relative;
     height: 0.7rem;
     width: 1rem;
-    transition: -webkit-transform 300ms ease;
     transition: transform 300ms ease;
-    transition: transform 300ms ease, -webkit-transform 300ms ease;
   }
 
   &:hover {
@@ -62,6 +66,5 @@
 }
 
 .rotate {
-  -webkit-transform: rotate(-90deg);
   transform: rotate(-90deg);
 }

_sass/layout/home.scss

@@ -19,7 +19,7 @@
 
   .card {
     %img-radius {
-      border-radius: $card-radius $card-radius 0 0;
+      border-radius: $base-radius $base-radius 0 0;
     }
 
     .preview-img {
@@ -146,7 +146,7 @@
 @media all and (min-width: 768px) {
   #post-list {
     %img-radius {
-      border-radius: 0 $card-radius $card-radius 0;
+      border-radius: 0 $base-radius $base-radius 0;
     }
 
     .card {

_sass/layout/post.scss

@@ -205,12 +205,12 @@ h1 + .post-meta {
     }
 
     &:first-child {
-      border-radius: $card-radius 0 0 $card-radius;
+      border-radius: $base-radius 0 0 $base-radius;
       left: 0.5px;
     }
 
     &:last-child {
-      border-radius: 0 $card-radius $card-radius 0;
+      border-radius: 0 $base-radius $base-radius 0;
       right: 0.5px;
     }
   }