<!DOCTYPE html>
<html>
<head>
  <style>
    .container {
        width: 6ch;
        font-size: 100px;
        font-family: Ahem;
        outline: 1px solid gray;
        overflow: hidden;
    }
    .shadowed {
        color: transparent;
        line-height: 160px;
        border-radius: 80px;
        box-shadow: black 0px 0px 0px 40px inset;
    }
  </style>
</head>
<body>
<div class="container">
    <span class="shadowed">
        000000000000
    </span>
    <span class="shadowed" style="margin-left: -4ex">
        000000000000
    </span>
    <span class="shadowed" style="margin-left: -1ch">
        0000000
    </span>
</div>
</body>
</html>