:root{color-scheme:dark;font-family:system-ui,sans-serif;background:#101510;color:#ecf4e8}body{margin:0;min-height:100dvh;display:grid;place-items:center}main{max-width:460px;padding:24px;margin:12px;border:1px solid #34412c;border-radius:20px;background:#1b2318}.brand{color:#b9ec78;font-weight:800;font-size:12px;letter-spacing:2px}h1{font-size:25px}p{line-height:1.5}small{display:block;color:#b1bda9;line-height:1.6;margin-top:20px}button{background:#b9ec78;color:#18200f;border:0;border-radius:12px;padding:12px 18px;font-weight:700;cursor:pointer}#challenge{min-height:70px}