<!DOCTYPE html>
<html>
<head>
<title>CSS border-bottom-width Property</title>
<style>
div {
background: #eee;
display: flex;
height: 30px;
margin-bottom: 10px;
align-items: center;
justify-content: center;
border-bottom-color: pink;
border-bottom-style: solid;
}
.border-1 {
border-bottom-width: medium;
}
.border-2 {
border-bottom-width: thin;
}
.border-3 {
border-bottom-width: thick;
}
.border-4 {
border-bottom-width: 5px;
}
</style>
</head>
<body>
<div class="border-1">medium</div>
<div class="border-2">thin</div>
<div class="border-3">thick</div>
<div class="border-4">5px</div>
</body>
</html>