HTML / CSS

flex grid

.cssgrid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
grid-auto-rows: 1fr;
grid-gap: 0.8em;
border: 1px solid #ddd;
padding: 0.8em;
margin: 0 0 2em;
}

.cssgrid > div {
background: #ddd;
overflow: auto;
min-width: 0;
padding: 1em;
}

.cssgrid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
grid-auto-rows: 1fr;
grid-gap: 0.8em;
border: 1px solid #ddd;
padding: 0.8em;
margin: 0 0 2em;
}

.cssgrid > div {
background: #ddd;
overflow: auto;
min-width: 0;
padding: 1em;
}