[Glitch] Fix edit media modal on small screens, touch events

Port 1bea318197 to glitch-soc

Signed-off-by: Thibaut Girka <thib@sitedethib.com>

app/javascript/flavours/glitch/styles/components/modal.scss

@@ -829,6 +829,11 @@
   position: relative;
   cursor: move;
   overflow: hidden;
+  height: 100%;
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  background: $base-shadow-color;
 
   img,
   video {
@@ -879,6 +884,17 @@
       box-shadow: 0 0 14px rgba($base-shadow-color, 0.2);
     }
   }
+
+  @media screen and (max-width: 480px) {
+    img,
+    video {
+      max-height: 100%;
+    }
+
+    &__preview {
+      display: none;
+    }
+  }
 }
 
 .filtered-status-info {