Fix overflowing content with custom stage size

Author: GarboMuffin

src/playground/interface.css

@@ -46,8 +46,6 @@ a {
 }
 
 .editor {
-    min-width: 1024px;
-    min-height: 640px;
     height: 100%;
 }
 .editor .center {

src/playground/render-interface.jsx

@@ -218,6 +218,10 @@ class Interface extends React.Component {
                     [styles.playerOnly]: isHomepage,
                     [styles.editor]: isEditor
                 })}
+                style={{
+                    minWidth: isEditor ? 1024 + Math.max(0, this.props.customStageSize.width - 480) : '',
+                    minHeight: isEditor ? 640 + Math.max(0, this.props.customStageSize.height - 360) : ''
+                }}
             >
                 {isHomepage ? (
                     <div className={styles.menu}>