* { box-sizing: border-box; } .block > div{ margin: 0; padding: 0; } .block { max-width: 400px; width: 100%; height: 100%; float: left; padding: 15px; z-index: 10; background-color: white; overflow: hidden; } @media screen and (max-width: 599px) { .block { max-width: 100%; } } .block > div { display: block; position: relative; padding: 0 0 0 35px; border-bottom: 1px solid white; background-color:
![[CSS]レスポンシブ対応、高さ可変のアコーディオンをピュアCSSで実装するテクニック | コリス](https://cdn-ak-scissors.b.st-hatena.com/image/square/ed40b33996ad99527e2885410af7d472ef9e6b3b/height=288;version=1;width=512/https%3A%2F%2Fcoliss.com%2Fwp-content%2Fuploads-201604%2F2016110708.png)