fix(all): game window size and unused files

css/style.css

@@ -1,7 +1,14 @@
+/* Use border-box globally to avoid unexpected overflow from padding/borders */
+*, *::before, *::after {
+  box-sizing: border-box;
+}
+
 html,
 body {
   margin: 0;
-  min-height: 100%;
+  height: 100%;
+  /* Prevent global scrollbars — inner panels manage their own scrolling */
+  overflow: hidden;
 }
 
 body.maze-page {
@@ -17,22 +24,24 @@ canvas {
 
 .canvas-stage {
   position: relative;
+  height: 100%;
 }
 
 .maze-layout {
   width: 100vw;
-  margin: 0;
+  padding: 12px; /* use padding instead of margin to avoid adding to viewport height */
   display: grid;
   grid-template-columns: 1fr;
   gap: 0;
   align-items: start;
   min-height: 100vh;
+  box-sizing: border-box;
 }
 
 .maze-layout > .panel:first-child {
-  margin: 12px;
+  margin: 0;
   border-radius: 16px;
-  height: calc(100vh - 24px);
+  height: calc(100vh - 24px); /* accounts for container padding */
 }
 
 .panel {
@@ -54,7 +63,8 @@ canvas {
 
 #renderCanvas {
   width: 100%;
-  height: min(76vh, 820px);
+  height: 100%;
+  display: block;
 }
 
 .canvas-hud {