textarea{line-height:2rem;background-image:repeating-linear-gradient(180deg,transparent,transparent 2rem,black 0,black calc(2rem + 1px))}.dark textarea{line-height:2rem;background-color:#1e293b;background-image:repeating-linear-gradient(180deg,transparent,transparent 2rem,#d1d5db 0,#d1d5db calc(2rem + 1px))}