// Functions
// --------------------------------------------------

replace(expr, str, val)
	expr = clone(expr)
	for e, i in expr
		if str == e
			expr[i] = val
	expr

// Convert typographic units
// 100% = 1em ~= 16px ~= 14pt
// ----------------------------
px(amount, ignore-base = false)
	if unit(amount) == "%"
		amount = percent(base-font-size, ignore-base) / percent(base-font-size, true) * (amount / 100) * 16
	else if unit(amount) == "em" or unit(amount) == "rem"
		amount = em(base-font-size, ignore-base) / em(base-font-size, true) * amount * 16
	else if unit(amount) == "pt"
		amount = pt(base-font-size, ignore-base) / pt(base-font-size, true) * (amount / 14) * 16
	else if unit(amount) == "px" or unit(amount) == ""
		if (unit(base-font-size) != "px") && !ignore-base
			amount = px(base-font-size, true) / 16 * amount
		else if !ignore-base
			amount = base-font-size / 16 * amount

	unit(amount, "px")

pt(amount, ignore-base = false)
	if unit(amount) == "%"
		amount = percent(base-font-size, ignore-base) / percent(base-font-size, true) * (amount / 100) * 14
	else if unit(amount) == "em" or unit(amount) == "rem"
		amount = em(base-font-size, ignore-base) / em(base-font-size, true) * amount * 14
	else if unit(amount) == "px"
		amount = px(base-font-size, ignore-base) / px(base-font-size, true) * (amount / 16) * 14
	else if unit(amount) == "pt" or unit(amount) == ""
		if (unit(base-font-size) != "pt") && !ignore-base
			amount = pt(base-font-size, true) / 14 * amount
		else if !ignore-base
			amount = base-font-size / 14 * amount

	unit(amount, "pt")

em(amount, ignore-base = false)
	if unit(amount) == "%"
		amount = percent(base-font-size, ignore-base) / percent(base-font-size, true) * (amount / 100)
	else if unit(amount) == "px"
		amount = px(base-font-size, ignore-base) / px(base-font-size, true) * (amount / 16)
	else if unit(amount) == "pt"
		amount = pt(base-font-size, ignore-base) / pt(base-font-size, true) * (amount / 14)
	else if unit(amount) == "em" or unit(amount) == "rem" or unit(amount) == ""
		if (unit(base-font-size) != "em") && !ignore-base
			amount = em(base-font-size, true) * amount
		else if !ignore-base
			amount = base-font-size * amount

	unit(amount, "em")

rem(amount, ignore-base = false)
	if support-for-ie
		add-property(current-property[0], replace(current-property[1], "__CALL__", px(em(amount, true), ignore-base)))
	unit(em(amount, ignore-base), "rem")

percent(amount, ignore-base = false)
	if unit(amount) == "px"
		amount = px(base-font-size, ignore-base) / px(base-font-size, true) * (amount / 16) * 100
	else if unit(amount) == "em" or unit(amount) == "rem"
		amount = em(base-font-size, ignore-base) / em(base-font-size, true) * amount * 100
	else if unit(amount) == "pt"
		amount = pt(base-font-size, ignore-base) / pt(base-font-size, true) * (amount / 14) * 100
	else if unit(amount) == "%" or unit(amount) == ""
		if (unit(base-font-size) != "%") && !ignore-base
			amount = percent(base-font-size, true) / 100 * amount
		else if !ignore-base
			amount = base-font-size / 100 * amount

	unit(amount, "%")