:root {
--side-bar-width: 220px;
--sb-shadow-width: 20px;
}
html {
background:
linear-gradient(90deg, rgba(2,0,36,1) 0%, rgba(0,0,0,1) var(--side-bar-width), rgba(15,15,15,1) calc(var(--side-bar-width) + 0.1px), rgba(255,255,255,0) calc(var(--side-bar-width) + var(--sb-shadow-width)), rgba(255,255,255,0) 100%);
}