/* The outer document owns fullscreen; only the course frame changes. */
.lesson-frame{position:fixed;inset:0;z-index:1000;display:block;width:100%;height:100%;border:0;background:#b7e5f5}
.lesson-frame[hidden],.park[hidden]{display:none!important}
body.in-lesson{overflow:hidden;display:block}
body.in-lesson .fullscreen-notice{z-index:2000}