JSFiddle - React, Tailwind, and code Playground

HTML

<label class="looks_like_input">domain.com/usernamessssssssssssssssssssssssss/<input type="text" value="all-about-kitties"></label>

CSS

.looks_like_input {
    border: 1px inset;
    padding: 0 3px;
    font-weight: bold;
}
.looks_like_input input {
    border: 0;
    font-weight: normal;
}