Style gameday playback controls

frontend/src/pages/GamedayPage.tsx

@@ -405,10 +405,15 @@ export function GamedayPage() {
             <span className="muted">{nowPlaying.subtitle}</span>
           </div>
           <div className="gameday-toolbar-actions">
-            <button type="button" className="btn btn-outline-secondary btn-sm" onClick={() => stopPlayback()}>
+            <button type="button" className="btn btn-danger btn-sm" onClick={() => stopPlayback()}>
               Stop
             </button>
-            <button type="button" className="btn btn-outline-secondary btn-sm" onClick={() => fadeOutPlayback()}>
+            <button
+              type="button"
+              className="btn btn-outline-secondary btn-sm d-inline-flex align-items-center gap-2"
+              onClick={() => fadeOutPlayback()}
+            >
+              <i className="bi bi-volume-down-fill" aria-hidden="true" />
               Fade out
             </button>
           </div>