How to lay out blocks on a grid using bootstrap?

Question

css

it is necessary that all blocks are equal in height and with equal indents, and on a mobile phone a large block is full width and 4 small ones under it are also full width

Answer 1

But on bootstrap everything is simple

<div class="row">
    <div class="col-md-6 block"></div>
    <div class="col-md-6 block">
        <div class="col-md-6 block"></div>
        <div class="col-md-6 block"></div>
        <div class="col-md-6 block"></div>
        <div class="col-md-6 block"></div>
    </div>
</div>

.block {
background: #f48942;
border-radius: 5px;

On the mobile version, write down your block sizes. And make adaptability the way you like it!
There are many guides on YouTube about it!