CSS: Super simple design guides

Needed to see if I had lined some stuff up correctly on a website I’m making. Came up with this simple CSS to add two guides to the page that I can move around freely in the browser developer console (just nudge their position around to where I need them).

It’s really simple, but for some reason didn’t think of it until now…

html::after {
    content: "";
    height: 1px;
    width: 100%;
    background: red;
    position: fixed;
    left: 0;
    bottom: 5px; /* Change this to move the guide horizontally */
}
html::before {
    content: "";
    height: 100%;
    width: 1px;
    background: red;
    position: fixed;
    top: 0;
    right: 5px; /* Change this to move the guide vertically */
}