:root{--bg:#fafafa;--fg:#222;--muted:#666;--primary:#1e88e5;--card:#fff}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{background:var(--bg);color:var(--fg);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,"Hiragino Kaku Gothic ProN",Meiryo,sans-serif;line-height:1.6}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
input[type=radio]{accent-color:var(--primary)}
code,pre{font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace}