fix: resolve preview size issue

js/preview.js

@@ -7,7 +7,11 @@ export function updateLivePreview(state) {
   const cw = container.clientWidth;
   if (cw <= 0) return;
 
-  const scale = cw / state.fieldW;
+  const maxH = window.innerHeight - 140;
+  const scaleW = cw / state.fieldW;
+  const scaleH = maxH / state.fieldH;
+  const scale = Math.min(scaleW, scaleH);
+
   const field = $('field');
   field.style.width = state.fieldW + 'px';
   field.style.height = state.fieldH + 'px';

style.css

@@ -441,7 +441,9 @@ main {
 }
 
 #field {
-  position: relative;
+  position: absolute;
+  top: 0;
+  left: 0;
   transform-origin: 0 0;
   background: #0c1018;
 }
@@ -502,7 +504,6 @@ body.mode-preview .right-col {
 }
 
 body.mode-preview .left-col {
-  max-width: 900px;
   width: 100%;
 }