message: fix styling issues
  - grow/shrink between min and max height correctly
  - don't grow wider than available space
  - some space between editor and buttons
diff: @@ -16,17 +16,22 @@ limitations under the License.
  .mx_SendMessageComposer {
  flex: 1;
  - min-height: 50px;
  display: flex;
  flex-direction: column;
  font-size: 14px;
  justify-content: center;
  display: flex;
  + margin-right: 6px;
  + // don't grow wider than available space
  + min-width: 0;
  .mx_BasicMessageComposer {
  flex: 1;
  display: flex;
  flex-direction: column;
  + // min-height at this level so the mx_BasicMessageComposer_input
  + // still stays vertically centered when less than 50px
  + min-height: 50px;
  .mx_BasicMessageComposer_input {
  padding: 3px 0;
  @@ -35,6 +40,9 @@ limitations under the License.
  // while keeping the autocomplete at the top
  // of the composer. The parent needs to be a flex container for this to work.
  margin: auto 0;
  + // max-height at this level so autocomplete doesn't get scrolled too
  + max-height: 140px;
  + overflow-y: auto;
  }
  }
  }
  