details{border-block-end:1px solid #000;margin-block:.5rem;padding-block:.5rem}summary{position:relative;anchor-name:--summary;cursor:pointer;&::marker{content:""}&::before,&::after{content:"";border-block-start:2.5px solid #12617c;height:0;width:1rem;inset-block-start:50%;inset-inline-end:0;position:absolute;position-anchor:--summary;position-area:top end}&::after{transform:rotate(90deg);transform-origin:50%}}details[open] summary::after{transform:rotate(0deg)}