`display: flex`か`display: grid`で`gap`を使う。 --- ```html:横に50pxの要素を並べて、要素間は10px間隔 <div style="display: flex; gap: 10px"> <div class="grey-box">1</div> <div class="grey-box">2</div> <div class="grey-box">3</div> </div> ``` ↓ <div style="display: flex; gap: 10px"> <div class="grey-box">1</div> <div class="grey-box">2</div> <div class="grey-box">3</div> </div>