Where is your html Code?
Fact is, you have only two containers, this will not working,becouse you need three of them, look at the following example:
<div class="container0">
<div class="container1"></div>
<div class="container2"></div>
</div>
<style>
.container0 {
display:flex;
height:500px; <-- height must be selected when there is a value on
align-items!
width:500px; <-- width must be always selected when there is a
display:flex
}
.container1 {
width:250px;
height:100%;
background:Red;
}
.container2 {
width:250px;
height:100%;
background:blue;
}
</style>
I’ve edited your post for readability. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.
You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.