Simplified: .fa-border border-color is var(--fa-border-color #eee) border-radius is var(--fa-border-radius 0.1em) border-style is var(--fa-border-style solid) bor...
Simplified: .fa-li left is calc(-1 * var(--fa-li-width 2em)) position is absolute text-align is center width is var(--fa-li-width 2em) line-height is inherit