style(front): color disabled player button

front/src/style/components/_player.scss

@@ -28,6 +28,7 @@
   margin: 0;
   z-index: 1001;
   height: $bottom-player-height;
+  cursor: pointer;
   .controls-row {
     height: $bottom-player-height;
     margin: 0 auto;
@@ -39,7 +40,6 @@
       justify-content: space-around;
     }
   }
-  cursor: pointer;
   .indicating.progress {
     overflow: hidden;
   }
@@ -137,6 +137,10 @@
           transform: scale(1.2);
         }
       }
+
+      &:disabled i {
+        color: var(--fw-gray-700);
+      }
     }
 
     #volume-slider {