Remove an obsolete CSS declaration and add a test to `file-panel.spec.ts` (#10498)

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

cypress/e2e/right-panel/file-panel.spec.ts

@@ -210,6 +210,22 @@ describe("FilePanel", () => {
                 });
             });
         });
+
+        it("should not add inline padding to a tile when it is selected with right click", () => {
+            // Upload a file
+            uploadFile("cypress/fixtures/1sec.ogg");
+
+            cy.get(".mx_FilePanel .mx_RoomView_MessageList").within(() => {
+                // Wait until the spinner of the audio player vanishes
+                cy.get(".mx_InlineSpinner").should("not.exist");
+
+                // Right click the uploaded file to select the tile
+                cy.get(".mx_EventTile").rightclick();
+
+                // Assert that inline padding is not applied
+                cy.get(".mx_EventTile_selected .mx_EventTile_line").should("have.css", "padding-inline", "0px");
+            });
+        });
     });
 
     describe("download", () => {

res/css/structures/_FilePanel.pcss

@@ -111,10 +111,6 @@ limitations under the License.
     .mx_EventTile_line {
         margin-inline-end: 0;
         padding-inline-start: 0;
-
-        .mx_EventTile_selected & {
-            padding-inline-start: 0;
-        }
     }
 }