Reorder items to utilize space optimally-CodePudding

Imagine this set of items in a container (I'm trying with flexbox):

1 2 3

4 5

7 8 9

Where item 6 is 100% width, whereas the other items have 33% width. I don't want the space to the right of item 5 to be left empty, instead I would want this:

1 2 3

4 5 7

8 9

Is this possible to do with CSS? I could solve this backend for content that doesn't change. But we have media queries that change the number of columns depending on the device you're using.

Code:

.container {
  display: flex;
  flex-wrap: wrap;
}
.container > * {
  width: 33%;
}
.fullsize {
  width: 100%;
}

<div >
  <div>1</div>
  <div>2</div>
  <div>3</div>
  <div>4</div>
  <div>5</div>
  <div >6</div>
  <div>7</div>
  <div>8</div>
  <div>9</div>
</div>

CodePudding user response：

This is a use case of CSS grid

.box {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr; /* 3 columns */
  gap: 5px;
  grid-auto-flow: dense; /* don't leave empty areas */
}

.box > div {
  border: 1px solid red;
  font-size: 30px;
}
.big {
  grid-column: 1/-1; /* 100% width */
}

@media (max-width: 600px) {
 .box {
    grid-template-columns: 1fr 1fr; /* 2 columns */
 }
}

<div >
  <div>1</div>
  <div>2</div>
  <div>3</div>
  <div>4</div>
  <div>5</div>
  <div >6</div>
  <div>7</div>
  <div>8</div>
  <div>9</div>
</div>

CodePudding user response：

My approach using flexbox

* {
  box-sizing: border-box;
}

.container {
  max-width: 600px;
  min-width: fit-content;
  max-height: fit-content;
  margin: auto;
  background-color: rgba(20, 20, 20, .2);
  display: flex;
  flex-flow: wrap row;
}

.container-items:nth-child(n) {
  flex-basis: 33.3%;
  outline: 1px solid black;
  text-align: center;
  padding: 1em;
}


/* Put item 6th to ordinal group 1  */

.container-items:nth-child(6) {
  flex-basis: 100%;
  order: 1;
}


/* Put items 1st to 5th to ordinal group 0  */

.container-items:nth-child(n 1):nth-child(-n 5) {
  order: 0;
}


/* Put items 8th to 9th to ordinal group 2  */

.container-items:nth-child(n 8):nth-child(-n 9) {
  order: 2;
}

<div >
  <div >1</div>
  <div >2</div>
  <div >3</div>
  <div >4</div>
  <div >5</div>
  <div >6</div>
  <div >7</div>
  <div >8</div>
  <div >9</div>
</div>

The order property controls the order in which flex items appear within the flex container, by assigning them to ordinal groups. It takes a single value, which specifies which ordinal group the flex item belongs to. For more about order - link