:root{--bg:#f4f4ef;--panel:#fff;--ink:#20231f;--muted:#5f655f;--accent:#1f5e4a}*{box-sizing:border-box}body{margin:0;font-family:Source Sans\ 3,Segoe UI,sans-serif;background:radial-gradient(circle at 15% 10%,#dde6d8 0,var(--bg) 45%);color:var(--ink)}main{max-width:920px;margin:48px auto;background:var(--panel);border:1px solid #d6ddd5;border-radius:16px;padding:24px}button{background:var(--accent);color:#fff;border:0;border-radius:8px;padding:10px 14px;cursor:pointer}small{color:var(--muted)}pre{background:#eef3ed;border-radius:8px;padding:12px;overflow:auto}