Refactoring thumbnails. Fixes #564

- Adding a default discussion thumbnail
- Adding a cropping max-height, and consistent width.
- Getting rid of hover overlays, in favor of top right content-type icon.

ui/assets/css/main.css

@@ -131,8 +131,13 @@ blockquote {
 }
 
 .thumbnail {
-  max-height: 62px;
-  max-width: 400px;
+  object-fit: cover;
+  max-height: 80px;
+  width: 100%;
+}
+
+svg.thumbnail {
+  height: 40px;
 }
 
 .no-s-hows {
@@ -188,6 +193,16 @@ hr {
   border: unset;
 }
 
+.mini-overlay {
+  position: absolute;
+  top: 0;
+  right: 0;
+  padding: 2px;
+  background: rgba(0,0,0,.4);
+  border-bottom-left-radius: 0.25rem !important;
+  border-top-right-radius: 0.25rem !important;
+}
+
 .link-overlay:hover {
   transition: .1s;
   opacity: 1;

ui/src/components/symbols.tsx

@@ -15,6 +15,10 @@ export class Symbols extends Component<any, any> {
         xmlnsXlink="http://www.w3.org/1999/xlink"
       >
         <defs>
+          <symbol id="icon-bubble2" viewBox="0 0 32 32">
+            <title>bubble2</title>
+            <path d="M16 6c-1.717 0-3.375 0.271-4.928 0.804-1.46 0.502-2.76 1.211-3.863 2.108-2.069 1.681-3.209 3.843-3.209 6.088 0 1.259 0.35 2.481 1.039 3.63 0.711 1.185 1.781 2.268 3.093 3.133 0.949 0.625 1.587 1.623 1.755 2.747 0.056 0.375 0.091 0.753 0.105 1.129 0.233-0.194 0.461-0.401 0.684-0.624 0.755-0.755 1.774-1.172 2.828-1.172 0.168 0 0.336 0.011 0.505 0.032 0.655 0.083 1.325 0.126 1.99 0.126 1.717 0 3.375-0.271 4.928-0.804 1.46-0.502 2.76-1.211 3.863-2.108 2.069-1.681 3.209-3.843 3.209-6.088s-1.14-4.407-3.209-6.088c-1.104-0.897-2.404-1.606-3.863-2.108-1.553-0.534-3.211-0.804-4.928-0.804zM16 2v0c8.837 0 16 5.82 16 13s-7.163 13-16 13c-0.849 0-1.682-0.054-2.495-0.158-3.437 3.437-7.539 4.053-11.505 4.144v-0.841c2.142-1.049 4-2.961 4-5.145 0-0.305-0.024-0.604-0.068-0.897-3.619-2.383-5.932-6.024-5.932-10.103 0-7.18 7.163-13 16-13z"></path>
+          </symbol>
           <symbol id="icon-image" viewBox="0 0 32 32">
             <title>image</title>
             <path d="M29.996 4c0.001 0.001 0.003 0.002 0.004 0.004v23.993c-0.001 0.001-0.002 0.003-0.004 0.004h-27.993c-0.001-0.001-0.003-0.002-0.004-0.004v-23.993c0.001-0.001 0.002-0.003 0.004-0.004h27.993zM30 2h-28c-1.1 0-2 0.9-2 2v24c0 1.1 0.9 2 2 2h28c1.1 0 2-0.9 2-2v-24c0-1.1-0.9-2-2-2v0z"></path>