:root{--bg:#f3f4f7;--fg:#14161a}[data-theme=dark]{--bg:#0e1014;--fg:#e7e9ee}*{box-sizing:border-box}body,html{margin:0;padding:0;height:100%}body{background:var(--bg);color:var(--fg);font-family:-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;transition:background .2s ease,color .2s ease}