To align vertically a "label" and "input" inside a "div" with CSS, we use flexbox.
For instance, we write
<div>
<label for="name">Name:</label>
<input type="text" id="name" />
</div>
to add a label and input.
Then we write
div {
height: 50px;
background: grey;
display: flex;
align-items: center;
}
to make the div a flex container with display: flex;
Then we vertically center the items in the div with align-items: center;
.