Hi this is my example layout on mobile device.
https://codesandbox.io/s/cocky-dust-xuurof?file=/src/styles.css
On the wider screen the third element must be the same width like a second yellow element. The second and the third element. The second and third items together are the same height as the first item. The html structure cannot change, I need use Flexbox, not css grid.
.App {
font-family: sans-serif;
text-align: center;
display: flex;
border: 2px solid black;
flex-wrap: wrap;
}
.one {
background-color: red;
flex-basis: 120px;
height: 80px;
}
.two {
background-color: yellow;
flex-grow: 1;
}
.three {
background-color: green;
height: 30px;
flex-basis: 100%;
}
@media only screen and (min-width: 500px) {
.one {}
.two {}
.three {}
}
<div class="App">
<div class="one">1</div>
<div class="two">2</div>
<div class="three">3</div>
</div>