html – 如何根据div内部制作一个可伸缩的div

这里有很多答案！

以下示例适用于所有屏幕尺寸/宽度,最多3个框.

@media用于在每个视口宽度处给出边框,一列最多三列.它还会为每个步骤重新调整外部div的大小,并根据需要更改背景颜色等.请参阅代码段中的注释,以获取有关正在进行的操作的基本说明.

此示例可以根据需要使用任意数量的盒子.全屏打开并调整大小以查看结果.

更新 – 我给了内部一个深绿色背景,外部显示：内联块以调整其内容的大小.

* {
  box-sizing: border-box;
  /* incorporate padding into width (.outer_div padding is excluded) */
}
.outer_div {
  margin: 50px;
  display: inline-block;
  max-width: 640px;
  min-width: 240px;
  /* 200 * 3 across + 40 .outer_div padding = 640 */
  padding: 20px;
  /* transition? yes! on re-size! */
  transition: background 1s;
  transition: max-width 0.05s;
}
.inner_div {
  min-height: 238px;
  /* BORDER ALL THE THINGS!!!*/
  border: 1px dashed #000;
  float: left;
  padding: 9px;
  /* padding is accounted for in the width thanks to border-box */
  width: 200px;
  background: #0a8f08;
}
/* Clear the floats at the very end */

.outer_div:after {
  content: ' ';
  display: block;
  clear: left;
}
/* 3 boxes across */

/*@media sizes increase and decrease dependant on inner box width and outer_div padding */

@media screen and (min-width: 756px) {
  .outer_div {
    background: #a3e9a4;
  }
  /* Remove all bottom borders */
  .inner_div {
    border-bottom: none
  }
  /* Remove every middle border  */
  .inner_div:nth-child(3n+2) {
    border-right: none;
    border-left: none;
  }
  /* Last child gets a right border  */
  .inner_div:last-child {
    border-right: 1px dashed #000;
  }
  /* last three get a bottom border */
  .inner_div:nth-last-child(-n+3) {
    border-bottom: 1px dashed #000;
  }
}
/* 2 boxes across */

@media screen and (min-width: 573px) and (max-width: 755px) {
  .outer_div {
    max-width: 440px;
    background: #dcedc8;
  }
  /* Remove all bottom borders */
  .inner_div {
    border-bottom: none;
  }
  /* Remove every second border */
  .inner_div:nth-child(2n) {
    border-left: none;
  }
  /* last two get a bottom border */
  .inner_div:nth-last-child(-n+2) {
    border-bottom: 1px dashed #000;
  }
}
/* 1 box across */

@media screen and (max-width: 572px) {
  .outer_div {
    max-width: 240px;
    background: #f0f4c3;
  }
  /* Remove all bottom borders */
  .inner_div {
    border-bottom: none;
  }
  /* last one gets a border */
  .inner_div:last-child {
    border-bottom: 1px dashed #000;
  }
}

<div class="outer_div">
  <div class="inner_div"></div>
  <div class="inner_div"></div>
  <div class="inner_div"></div>
  <div class="inner_div"></div>
  <div class="inner_div"></div>
  <div class="inner_div"></div>
</div>