.page__content {
    & .demo {
        background-color: lightcyan;
        border: 1px solid black;
        border-radius: 2rem;

        & .demo__menu {
            list-style: none;
            margin: 3rem;
            position: relative;

            &::after {
                background-color: red;
                clip-path: circle(1rem);
                content: '';
                height: 2rem;
                position: absolute;
                position-anchor: --thumb;
                right: calc(anchor(left) + 1rem);
                transition: top 0.5s ease;
                top: calc(anchor(top) + 1rem);
                width: 2rem;
            }

            & .demo__menu__item {
                border: 1px solid lightblue;
                cursor: pointer;
                margin: 0.25rem 0;
                padding: 1rem;
                user-select: none;

                &:first-child {
                    anchor-name: --thumb;
                }

                &:hover {
                    anchor-name: --thumb;
                    border: 1px solid blue;
                }
            }
        }
    }
}