" Allow backspacing.
set backspace=indent,eol,start
" Syntax highlighting.
syntax on
" Vertical rule highlighting.
set colorcolumn=81
hi ColorColumn ctermbg=245
" Vertical line highlighting.
set cursorcolumn
hi CursorColumn ctermbg=238
" Horizontal line highlighting.
set cursorline
hi clear CursorLine
hi clear CursorLineNr
hi link CursorLine CursorColumn
hi link CursorLineNr CursorColumn
" Numbering.
set number
set relativenumber
" Indentation.
set expandtab
set shiftwidth=4
set tabstop=4
" Nix.
autocmd BufRead,BufNewFile *.nix set filetype=nix
autocmd Filetype nix set shiftwidth=2
autocmd Filetype nix set tabstop=2