Merge pull request #2075 from hypothesis/fix-thread-overflow

Fix overflow on Thread contents

src/styles/sidebar/components/thread.scss

@@ -53,7 +53,8 @@
 
   &__content {
     flex-grow: 1;
-    // Prevent annotation content from overflowing the container
-    max-width: 100%;
+    // Prevent long, non-wrapping content (typically URLs) from exceeding
+    // the width of the annotation card
+    overflow: hidden;
   }
 }