nvim/lua/catppuccin/core/integrations/bufferline.lua

local M = {}

function M.get(cp)
	local cnf = require("catppuccin.config").options
	local transparent_background = cnf.transparent_background
	local dim_inactive = cnf.dim_inactive
	local bg_highlight = (transparent_background and dim_inactive and cp.dim)
		or (transparent_background and "NONE")
		or (dim_inactive and cp.dim)
		or cp.base

	local inactive_bg = transparent_background and "NONE" or cp.mantle

	return {
		BufferLineFill = { bg = bg_highlight },
		BufferLineBackcrust = { fg = cp.text, bg = inactive_bg }, -- others
		BufferLineBufferVisible = { fg = cp.surface1, bg = inactive_bg },
		BufferLineBufferSelected = { fg = cp.text, bg = cp.base, style = "bold,italic" }, -- current
		BufferLineTab = { fg = cp.surface1, bg = cp.base },
		BufferLineTabSelected = { fg = cp.red, bg = cp.blue },
		BufferLineTabClose = { fg = cp.red, bg = inactive_bg },
		BufferLineIndicatorSelected = { fg = cp.peach, bg = cp.base },
		-- separators
		BufferLineSeparator = { fg = inactive_bg, bg = inactive_bg },
		BufferLineSeparatorVisible = { fg = inactive_bg, bg = inactive_bg },
		BufferLineSeparatorSelected = { fg = inactive_bg, bg = inactive_bg },
		-- close buttons
		BufferLineCloseButton = { fg = cp.surface1, bg = inactive_bg },
		BufferLineCloseButtonVisible = { fg = cp.surface1, bg = inactive_bg },
		BufferLineCloseButtonSelected = { fg = cp.red, bg = cp.base },
	}
end

return M