Ligne claire is the world drawn so cleanly that a child and a cartographer both trust it: one uniform black outline around every object, one flat unmodulated color poured inside, and a horizon that never smudges. Born in 1929 with Hergé's Tintin, it refuses hatching, gradients, and cast-shadow drama so the eye reads a whole page instantly, like a travel poster.

As an interface it borrows album-cover logic — a bold framed vignette, a spot-color sky, a hand-lettered logotype arced across the top, and generous white gutters between panels. Pillar-box red and cobalt carry the accents, poster yellow and meadow green fill the world, and everything sits calm and orthogonal on the printed daylight of a 1940s Petit Vingtième cover.