Fix Safari iframe size

customize.dist/src/less/toolbar.less

@@ -43,8 +43,6 @@
     right: 0;
     display: flex;
     flex-flow: column;
-    height: 100vh;
-    width: 100vw;
 }
 .cke_toolbox_main {
     display: inline-block;
@@ -56,7 +54,7 @@
     display: flex;
     overflow: visible;
     iframe {
-        height: 100%;
+        min-height: 100%;
         width: 100%;
     }
 }