.wpcf7-math_captcha {
  border: none;
  border-bottom: 1px solid #707070;
  border-radius: 0;
  height: 50px;
  color: #fff;
  font-size: 14px;
  font-weight: 500;
  width: 100%;
  background: transparent;
  outline: none;
}
button.regenrate-captcha {
    padding: 5px 10px;
    color: inherit;
    position: absolute;
    top: 12px;
    left: 185px;
    border: none;
    background: transparent;
    outline: none;
}