高度等於動態寬度（CSS 流體佈局）[重複] - Height equal to dynamic width (CSS fluid layout) [duplicate]

問題：

This question already has answers here : 這個問題在這裏已經有了答案：

Maintain the aspect ratio of a div with CSS (35 answers) 使用 CSS 保持 div 的縱橫比（35 個回答）

Closed 6 years ago . 6年前關閉。

Is it possible to set same height as width (ratio 1:1)?是否可以設置與寬度相同的高度（比例爲 1:1）？

Example例子

+----------+
| body     |
| 1:3      |
|          |
| +------+ |
| | div  | |
| | 1:1  | |
| +------+ |
|          |
|          |
|          |
|          |
|          |
+----------+

CSS CSS

div {
  width: 80%;
  height: same-as-width
}

---

解決方案：

參考一： https://en.stackoom.com/question/MqcV
參考二： https://stackoom.com/question/MqcV