:root{font-family:Inter,system-ui,sans-serif;color:#0f172a;background:#f8fafc}*{box-sizing:border-box}body{margin:0;min-height:100vh;background:#f1f5f9}.app-shell{padding:24px}.page{max-width:940px;margin:0 auto}.card{background:#fff;padding:20px;border-radius:12px;box-shadow:0 20px 45px #0f172a1a;display:flex;flex-direction:column;gap:12px}.card label{display:flex;flex-direction:column;font-weight:600;gap:4px}.card input,.card textarea{border:1px solid #cbd5f5;border-radius:8px;padding:10px;font:inherit}button{background:#0f172a;color:#fff;border:none;border-radius:8px;padding:12px 16px;cursor:pointer}button:disabled{opacity:.6;cursor:not-allowed}.error{color:#b91c1c;font-weight:600}.result{border-left:4px solid #0f172a;padding-left:12px}