CSS remove empty space by translate-CodePudding

The expected result should be that the .item ( green color ) is followed by any element like p without any empty space like below:

I was trying to do this by translateY, but it just move the div .item going up and left an empty white space like the below:

.main {
  background-color: gray;
  display: flex;
  flex-direction: column;
  justify-content: center;
  margin-top: 150px;  /* For illustratoin purpose only to see the result */
  padding: 30px;
}

.item {
  background-color: green;
  height: 200px;
  transform: translateY(calc(-50% - 30px)); /* Here is my try */
  width: 100%;
}

<div >
  <div ></div>
  <p>Helloooooooooooooooooooooooooo</p>
</div>

I have also tried margin-top: -50%;, I thought it should work but it just going up which I think is not "50%", going so much more than -50% although I don't know why like below.

Edited: negative margin will only work if I know exactly what's its height, say its height is 200px, then I can do margin-top: -100px;. But now the height of .item is unknown/flexible where the height: 200px; in the code is just for illustration purposes.

.main {
  background-color: gray;
  display: flex;
  flex-direction: column;
  justify-content: center;
  margin-top: 150px;  /* For illustratoin purpose only to see the result */
  padding: 30px;
}

.item {
  background-color: green;
  height: 200px;
  margin-top: calc(-50% - 30px); /* Here is my try */
  width: 100%;
}

<div >
  <div ></div>
  <p>Helloooooooooooooooooooooooooo</p>
</div>

CodePudding user response：

The only way I can think of, is to
create a white background ::before pseudo element inside of your Item element, that way you can position it at top 50% but most importantly at height 50% - making that height actually relative to the Item's height:

/* QuickReset */
*, ::before, ::after  {margin:0; box-sizing: border-box;}

/* Just to visualize */
*, ::before, ::after {
  outline: 2px solid red;
  outline-offset: -1px;
}

body {
  background: #000;
}

.card {
  --padd: 30px;
  max-width: 70%;
  margin: 0 auto;
  padding: var(--padd) 0;
}

.card-item {
  position: relative;
  background-color: #3de821;
  margin: 0 var(--padd);
}

.card-item::before {
  content: "";
  position: absolute;
  z-index: -1;
  width: calc(100%   (var(--padd) * 2));
  height: 50%;
  top: 50%;
  left: calc(var(--padd) * -1);
  background-color: #fff;
}

.card-desc {
  background-color: #fff;
  padding: var(--padd);
}

<div >
  <div  style="height:140px;">140px height</div>
  <div >
    Hello.<br>Scroll down.....
  </div>
</div>

<div >
  <div  style="height:250px;">250px height</div>
  <div >
    Lorem ipsum dolor sit amet, consectetur adipisicing elit. Nulla a optio magni. Neque sed repellendus fugiat. Earum necessitatibus deleniti consectetur sequi, nemo iure, omnis molestias minima culpa ipsa rem nam.
  </div>
</div>

<div >
  <div  style="height:60px;">60px height</div>
  <div >
    Lorem ipsum dolor sit amet, consectetur adipisicing elit. Nulla a optio magni. Neque sed repellendus fugiat. Earum necessitatibus deleniti consectetur sequi, nemo iure, omnis molestias minima culpa ipsa rem nam.
  </div>

the reason for this solution being: margin cannot relate to the element height, and translate cannot act on sibling elements positions.

CodePudding user response：

Use another nested div:

.main {
  background-color: gray;
  display: flex;
  flex-direction: column;
  justify-content: center;
  margin-top: 150px;
  padding: 30px;
  padding-top: 0px;
}

.item {
  background-color: green;
  height: 200px;
  width: 100%;
}

.container {
  transform: translateY(calc(-50% - 30px));
}

<div >
  <div >
    <div ></div>
    <p>Helloooooooooooooooooooooooooo</p>
  </div>
</div>

CodePudding user response：

you can also use position absolute.

  .main {
            background-color: gray;
            position: relative;
            display: flex;
            flex-direction: column;
            justify-content: center;
            margin-top: 150px;  /* For illustratoin purpose only to see the result */
            padding: 30px;
          }
          
          .item {
            background-color: green;
            height: 300px;

            width: 70%;
            position: absolute;
            left: 50%;
            bottom: 50%;
            transform: translate(-50%, 0);
          }

  <div >
      <div ></div>
      <p>Helloooooooooooooooooooooooooo</p>
    </div>