local hl = function(name, opts)
    vim.api.nvim_set_hl(0, name, opts)
end
local gbhl = function(name, color)
    hl(name, { bg = color })
end

-- highlight extra white space with red
hl("ExtraWhitespace", { ctermbg = "red", bg = "#ff8888" })
vim.cmd [[match ExtraWhitespace /\s\+$/]]

-- make background transparent
gbhl("Normal", "none")
gbhl("EndOfBuffer", "none")
gbhl("SignColumn", "none")
gbhl("NeoTreeNormal", "none")
gbhl("NeoTreeNormalNC", "none")
gbhl("NeoTreeEndOfBuffer", "none")