Generate type scale for TailwindCSS

genscale.rb

#!/usr/bin/env ruby
if ARGV.empty?
  puts 'Usage: genscale.rb 1.125'
  exit 1
end

scale = ARGV.first.to_f
steps = %w[xs sm base lg xl 2xl 3xl 4xl 5xl 6xl 7xl 8xl 9xl]
offset = -2

puts "  /* Type scale: #{scale} */"
steps.each.with_index do |step, i|
  val = 1
  n = i + offset
  if n.negative?
    (-n).times { val /= scale }
  else
    n.times { val *= scale }
  end
  puts format('  --text-%<step>s: %<val>0.3frem;', step: step, val: val)
end

output.txt

  /* Type scale: 1.2 */
  --text-xs: 0.694rem;
  --text-sm: 0.833rem;
  --text-base: 1.000rem;
  --text-lg: 1.200rem;
  --text-xl: 1.440rem;
  --text-2xl: 1.728rem;
  --text-3xl: 2.074rem;
  --text-4xl: 2.488rem;
  --text-5xl: 2.986rem;
  --text-6xl: 3.583rem;
  --text-7xl: 4.300rem;
  --text-8xl: 5.160rem;
  --text-9xl: 6.192rem;