:root{--bg:#f6f7fb;--card:#fff;--accent:#0b5cff}
body{font-family:Inter,system-ui,Segoe UI,Arial;background:var(--bg);color:#111;margin:0}
.container{max-width:820px;margin:32px auto;padding:16px}
h1{margin:0 0 16px}
.controls{margin-bottom:16px}
.card{background:var(--card);padding:12px;border-radius:8px;box-shadow:0 1px 6px rgba(0,0,0,.06);margin-bottom:12px}
.error{color:#b00020}