Use spacing in config

resources/config

@@ -3,6 +3,7 @@
     // "position": "bottom", // Waybar position (top|bottom|left|right)
     "height": 30, // Waybar height (to be removed for auto height)
     // "width": 1280, // Waybar width
+    "spacing": 4, // Gaps between modules (4px)
     // Choose the order of the modules
     "modules-left": ["sway/workspaces", "sway/mode", "custom/media"],
     "modules-center": ["sway/window"],

resources/style.css

@@ -80,7 +80,6 @@ window#waybar.chromium {
 #idle_inhibitor,
 #mpd {
     padding: 0 10px;
-    margin: 0 4px;
     color: #ffffff;
 }