W3School TIY Editor

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<style>
* {
  box-sizing: border-box;
}

body {
  font-family: Arial, Helvetica, sans-serif;
}

/* 四个列并排浮动 */
.column {
  float: left;
  width: 25%;
  padding: 0 10px;
}

/* 移除由于内边距产生的额外左右外边距 */
.row {margin: 0 -5px;}

/* 在列之后清除浮动 */
.row:after {
  content: "";
  display: table;
  clear: both;
}

/* 响应式列  */
@media screen and (max-width: 600px) {
  .column {
    width: 100%;
    display: block;
    margin-bottom: 20px;
  }
}

/* 设置计数卡片的样式 */
.card {
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
  padding: 16px;
  text-align: center;
  background-color: #f1f1f1;
}
</style>
</head>
<body>

<h2>响应式列卡片</h2>
<p>调整浏览器窗口大小可查看效果。</p>

</body>
</html>