.frm{top:-.17em;right:-.17em;bottom:-.17em;left:-.17em;color:red;box-shadow:0 0 .4px;filter:hue-rotate(40deg)}
.frm:after{border:solid .05em;background:
url(../mask/corner9a.svg).017em .017em/.75em,
url(../mask/corner9b.svg)calc(100% - .017em) .017em/.75em,
url(../mask/corner9c.svg)calc(100% - .017em) calc(100% - .017em)/.75em,
url(../mask/corner9d.svg).017em calc(100% - .017em)/.75em;
background-repeat:no-repeat;
filter:brightness(.5)url(#lightF4)
}