captcha.css

#captcha {
    background-color: #FFF;
    height: 20vh;
    min-height: 10px;
    max-width: 580px;
    margin: 0 auto;
}

#captcha .title {
    text-align: center;
    border-bottom: 2px solid #eee;
    margin-bottom: 30px;
    padding: 30px 0;
}

#captcha .captcha-from {
    max-width: 70%;
    margin: 0 auto;
}

#captcha .captcha-from label{
    font-weight: normal;
}

#captcha .form-control{
    border-radius: 0;
}
#captcha .input-group-addon {
    border-top-left-radius: 0 ;
    border-bottom-left-radius: 0;
}

#captcha .captcha-group div{
    display: inline-block;
}

#captcha .captcha-code .code{
    width: 200px;
    height: 10px;
    box-shadow: inset 0 1px 1px rgba(0,0,0,.075);
    
    transition: border-color ease-in-out .15s,box-shadow ease-in-out .15s;
}

#captcha .captcha-code .code .dynamic-code{
    text-shadow: 4px 4px 5px rgba(150, 150, 150, 1);
    color: #2d2d2;
    text-align: center;
    font-size: 28px;
    font-weight: 900;
    -webkit-touch-callout: none; /* iOS Safari */
    -webkit-user-select: none;   /* Chrome/Safari/Opera */
    -khtml-user-select: none;    /* Konqueror */
    -moz-user-select: none;      /* Firefox */
    -ms-user-select: none;       /* Internet Explorer/Edge */
    user-select: none;           /* Non-prefixed version, currently */
    cursor: help;

}

#captcha .captcha-code .code .dynamic-code:first-letter{
    font-size: 48px;

}

#captcha .captcha-code .captcha-reload{
    cursor: pointer;
    font-size: 36px;
    font-weight: bold;
    margin-top: 0;
    max-width: 36px;
}

#captcha .captcha-code .captcha-reload:hover{
    color: #00B16A;
}

#captcha #captcha-input{
    max-width: 200px;
    margin-top: 10px;
     border: 3px solid black;
}

#captcha .btn{
    border-radius:0;
}