How can I make four responsove children that change to a 2 by 2 grid when making the window smaller?

问题

I want to create four children that are next to each other. Now, when the viewport-width gets smaller, these are supposed to collaps to a two by two grid. (Less important: When it gets even smaller they shall be 100% of the parent's width.) Now my problem is not to create this with media queries. The problem is that the first child has a bigger height than the height of the second child. When they collaps to a 2 by 2 grid the third child is always placed below the second child and not (how I want it to be) below the first.
I've also tried flexbox but as far as I know there is no possibility to make it either 4 by 1, 2 by 2 or 1 by 4. The problem only occurs in some specific viewport widths because the number of lines is (in some situations) equal in the first and second child.
To see what I mean, here is a snippet:

*{
  padding: 0px;
  margin: 0px;
}

#parent{
  width: 960px;
  max-width: 90%;
  font-size: 1rem;
  margin: auto;
  background-color: green;
}

.child{
  width: 23%;
  margin: 0px 1%;
  background-color: yellow;
  float: left;
}

@media (max-width: 60rem){
  .child{
    width: 46%;
    margin: 2%;
    float: left;
  }
}

@media (max-width: 30rem){
  .child{
    width: 100%;
    margin: 0;
    float: none;
  }
}

<div id="parent">
  <div class="child">
    <h1>Lorem ipsum</h1>
    <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed</p>
  </div>
  <div class="child">
    <h1>Lorem ipsum</h1>
    <p>Lorem ipsum dolor sit amet, consetetur sadipscing</p>
  </div>
  <div class="child">
    <h1>Lorem ipsum</h1>
    <p>Lorem ipsum dolor sit amet, consetetur</p>
  </div>
  <div class="child">
    <h1>Lorem ipsum</h1>
    <p>Lorem ipsum dolor sit amet</p>
  </div>
</div>

回答1:

You can do it with the Grid:

* {margin: 0; padding: 0; box-sizing: border-box}

#parent {
  display: grid;
  grid-template-columns: repeat(4, 1fr); /* 4 x 25% / can also use 1fr 1fr 1fr 1fr or 25% 25% 25% 25%, without the repeat(), fr stands for fraction */
  grid-gap: 10px; /* 10px horizontal and vertical gap between child elements */
  width: 960px;
  max-width: 90%;
  font-size: 1rem;
  margin: auto;
  background: green;
}

.child {background: yellow}

@media (max-width: 60rem){
  #parent {
    grid-template-columns: repeat(2, 1fr); /* 2 x 50% / can also use 1fr 1fr or 50% 50%, without the repeat() */
  }
}

@media (max-width: 30rem){
  #parent {
    grid-template-columns: 1fr; /* 1 x 100% / can also use 100% */
  }
}

<div id="parent">
  <div class="child">
    <h1>Lorem ipsum</h1>
    <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed</p>
  </div>
  <div class="child">
    <h1>Lorem ipsum</h1>
    <p>Lorem ipsum dolor sit amet, consetetur sadipscing</p>
  </div>
  <div class="child">
    <h1>Lorem ipsum</h1>
    <p>Lorem ipsum dolor sit amet, consetetur</p>
  </div>
  <div class="child">
    <h1>Lorem ipsum</h1>
    <p>Lorem ipsum dolor sit amet</p>
  </div>
</div>

回答2:

add height property do class .child

来源：https://stackoverflow.com/questions/47237948/how-can-i-make-four-responsove-children-that-change-to-a-2-by-2-grid-when-making