.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 {
    background-color: #555 !important;
    color: #fff !important;
    border-radius: 50% !important;
    width: 35px;
    height: 35px;
    padding: 5px 10px;
    color: inherit;
    position: absolute;
    top: 12px;
    left: 185px;
    border: none;
    background: transparent;
    outline: none;
    display: block;
}
.captcha-error-text + input.captcha-input {
    border: 1px solid red;
}
.custom-math-captcha-wrap input.captcha-input {
    border: 1px solid #ccc;
}
.custom-math-captcha-wrap .captcha-error-text {
    color: red;
    font-size: 0.9em;
    margin-top: 4px;
}

.custom-math-captcha-wrap{
  position: relative;
  margin: 20px 0;
}

.custom-math-captcha-wrap input.captcha-input {
    border: 1px solid #ccc;
    border: none;
    border-bottom: 1px solid #707070;
    border-radius: 0;
    height: 40px;
    color: #000000;
    font-size: 14px;
    font-weight: 500;
    width: 100%;
    background: transparent;
    outline: none;
}