.eck-rahmen { --c: currentColor;  --s: 3px;  --rahmen-laenge: 300px;  --kappe: radial-gradient(circle closest-side, var(--c) calc(100% - 1px), transparent); position: relative; } .eck-rahmen::before, .eck-rahmen::after { content: ""; position: absolute; width: min(var(--rahmen-laenge), 50%); height: min(var(--rahmen-laenge), 50%); background-repeat: no-repeat; background-image: linear-gradient(var(--c), var(--c)), linear-gradient(var(--c), var(--c)), var(--kappe), var(--kappe); background-size: calc(100% - var(--s) / 2) var(--s), var(--s) calc(100% - var(--s) / 2), var(--s) var(--s), var(--s) var(--s); pointer-events: none; }  .eck-rahmen::before { top: 0; left: 0; background-position: left top, left top, right top, left bottom; }  .eck-rahmen::after { bottom: 0; right: 0; background-position: right bottom, right bottom, left bottom, right top; }  .eck-rahmen.eck-rahmen--gespiegelt::before { left: auto; right: 0; background-position: right top, right top, left top, right bottom; } .eck-rahmen.eck-rahmen--gespiegelt::after { right: auto; left: 0; background-position: left bottom, left bottom, right bottom, left top; }