,
{.label--checkbox input[type="checkbox"]{...}
right: -100%;
right: -300px;
либо transform: translateX(100%);
.b-sidebar__menu__item::after{
position: absolute;
top: 24px;
content: "";
width: 8px;
height: 8px;
border: 1px solid #000000;
border-width: 1px 0 0 1px;
transform: rotate(135deg);
right: 20px;
}
.b-sidebar__menu__item--clicked::after{
transform: rotate(77deg);
}
.e{
background-image: url("data:image/svg+xml;utf8,<svg>....</svg>")
}