:root{--primary: #6366f1;--bg: #f8fafc;--text: #1e293b}body{font-family:system-ui,sans-serif;background:var(--bg);color:var(--text);padding:2rem}.hidden{display:none}header{margin-bottom:2rem;border-bottom:1px solid #ddd;padding-bottom:1rem}button{padding:.5rem 1rem;cursor:pointer;border:none;background:var(--primary);color:#fff;border-radius:.5rem}section{background:#fff;padding:2rem;border-radius:1rem;box-shadow:0 4px 6px -1px #0000001a}