*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}body{font-family:Segoe UI,system-ui,-apple-system,sans-serif;background:#f8fafc;color:#1e293b;line-height:1.5}.fold-half{position:fixed;overflow:hidden;z-index:50;pointer-events:none;backface-visibility:hidden;-webkit-backface-visibility:hidden}