:root{--answer:#0d6efd;--bg:#f5f7fb;--card:#fff;--text:#1f2937;--muted:#6b7280}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}.sc-shell{min-height:100vh;display:grid;place-items:center;padding:24px}.sc-card{width:min(760px,100%);background:var(--card);border-radius:20px;box-shadow:0 16px 40px rgba(15,23,42,.12);padding:24px}h1{font-size:24px;margin:0 0 20px}.sc-chat{display:flex;flex-direction:column;gap:12px;min-height:420px;max-height:60vh;overflow:auto;padding:8px}.bubble{max-width:82%;padding:12px 14px;border-radius:16px;line-height:1.65;white-space:pre-wrap}.bubble.system{align-self:flex-start;background:#eef2f7}.bubble.answer{align-self:flex-end;background:var(--answer);color:#fff}.back-btn{margin-top:8px;border:0;background:rgba(255,255,255,.2);color:inherit;border-radius:999px;padding:4px 10px;cursor:pointer}.sc-input{border-top:1px solid #e5e7eb;margin-top:16px;padding-top:16px}.sc-input input,.sc-input textarea,.sc-input select{width:100%;border:1px solid #d1d5db;border-radius:12px;padding:12px;font-size:16px}.sc-input textarea{min-height:120px}.sc-input button,.choice{border:0;border-radius:999px;background:#111827;color:#fff;padding:11px 16px;margin-top:10px;cursor:pointer}.choices{display:flex;flex-wrap:wrap;gap:8px}.choice{margin-top:0}.sc-progress{margin-top:16px;color:var(--muted);font-size:13px}.sc-progress div{height:8px;background:#e5e7eb;border-radius:999px;overflow:hidden;margin-top:6px}.sc-progress b{display:block;height:100%;width:0;background:#111827;transition:width .2s}