I believe you need before and after selectors:
.example-number:before { content:""; position:absolute; bottom:-140px; right:0; border-width:0 0 140px 140px; border-style:solid; border-color:transparent #C91F2C; } .example-number:after { content:""; position:absolute; bottom:-140px; right:85px; border-width:0 0 140px 55px; border-style:solid; border-color:transparent #fff; }
Red is created using :before , and part of it is erased using :after .
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