simplify contain-svg css

sass/_default.scss

@@ -747,14 +747,6 @@ $thread_locked_background: none !default;
   align-items: center;
   justify-content: center;
   flex-direction: column;
-  &:not(.full) > svg, &:not(.full) > img {
-    height: 50%;
-    width: 50%;
-  }
-  &.full > svg, &.full > img {
-    height: 100%;
-    width: 100%;
-  }
 }
 
 $post_img_container_gap: $SMALL_PADDING !default;
@@ -797,11 +789,12 @@ $thread_info_header_gap: $SMALL_PADDING !default;
 .thread-info-header {
   display: flex;
   align-items: baseline;
+  justify-content: space-between;
   gap: $thread_info_header_gap;
 }
 
 .thread-info-bookmark-button {
-  margin-left: auto;
+  margin-left: auto !important; // :(
 }
 
 $thread_info_post_preview_margin_right: $post_inner_padding_right !default;