.fsp-jetpack-campaign-form { width:100%; }
.fsp-jetpack-campaign-fields { display:flex; gap:10px; align-items:stretch; }
.fsp-jetpack-campaign-form input[type="email"] {
  flex:1 1 auto; min-width:0; box-sizing:border-box;
  padding:14px 16px; border:1px solid #c8ced6; border-radius:9px;
  font:inherit; line-height:1.2; background:#fff;
}
.fsp-jetpack-campaign-form button {
  flex:0 0 auto; box-sizing:border-box; padding:14px 20px;
  border:0; border-radius:9px; font:inherit; font-weight:800;
  cursor:pointer; line-height:1.2;
}
@media (max-width:600px) {
  .fsp-jetpack-campaign-fields { flex-direction:column; }
  .fsp-jetpack-campaign-form button { width:100%; }
}