formulario.css

/* Página */
* {
    margin: 0;
    padding: 0;
    outline: none;
    font-family:Arial, Helvetica, sans-serif;
}
/* Estas declaraciones son para centrar el formulario y cambiar los fondos*/
body {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: url(CSS_Redes_Sociales/img_redes/banner-tec.jpg);
}
/* Aqui nos introducimos al formulario */
.container {
    width: 330px;
    background: #fff;
    border-radius: 5px;
    text-align: center;
    padding: 50px 35px 10px 35px;
}
.container header {
    font-size: 35px;
    font-weight: 600;
    margin: 0 0 30px 0;
}
.container .form-outer{
    width: 100%;
    overflow: hidden;
}
.form-outer form {
    display: flex;
    width: 400%;
}
/*** Aquí terminamos de centrar el formulario***/


/* A partir de aqui vamos dando forma a los elementos del fomulario */
.form-outer form .page {
    width: 25%; 
    transition: margin-left 0.3s ease-in-out;
}
.form-outer form .page .title {
    text-align: left;
    font-size: 25px;
    font-weight: 500;
}
.form-outer form .page .field {
    height: 45px;
    width: 330px;
    margin: 45px 0;
    display: flex;
    position: relative;
}
.form-outer form .page .field .label {
    position: absolute; 
    top: -30px;
    font-weight: 500;
}
.form-outer form .page .field input {
    height: 100%;
    width: 100%;
    border: 1px solid lightgrey;
    border-radius: 5px;
    font-size: 18px;
    padding-left: 15px;
}
form .page .field select {
    width: 100%;
    padding-left: 10px;
    font-size: 17px;
    font-weight: 500;
}
.form-outer form .page .field button {
    width: 100%;
    height: calc(100% + 5px);
    margin-top: -20px;
    border: none;
    background-image: linear-gradient(180deg, #b2eaff 0, #5389f2 50%, #003265 100%);
    border-radius: 5px;
    color: #fff;
    font-size: 18px;
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    cursor: pointer;
    transition: 0.3s ease;
}
.form-outer form .page .field button:hover {
    background: #000;
}
.form-outer form .page .btns button{
    margin-top: -20px!important;
}
form .page .btns button .prev {
    margin-right: 3px;
    font-size: 17px;
}
form .page .btns button .next {
    margin-left: 3px;
}
.container .progress-bar {
    display:flex;
    margin: 40px 0;
}
.container .progress-bar .step {
    position: relative;
    text-align: center;
    width: 100%;
}
.progress-bar .step p{
    font-size: 18px;
    font-weight: 500;
    color: #000;
    margin-bottom: 8px;
    transition: 0.2s;
}
.progress-bar .step p.active {
    color: #2980B9;
}
.progress-bar .step .bullet {
    position: relative;
    height: 25px;
    width: 25px;
    border: 2px solid #000;
    display: inline-block;
    border-radius: 50%;
    transition: 0.2s;
}

.progress-bar .step .bullet.active {
    border-color: #82E0AA ;
    background-image: linear-gradient(180deg, #b4f2a0 0, #a1ec9c 16.67%, #89e397 33.33%, #6cd890 50%, #49cd8a 66.67%, #10c488 83.33%, #00bd88 100%);
}

/* Los pseudo-elementos "before" y "after" sirven para insertar contenido mediante CSS,
"before" nos sirve para insertar por delante y "after" por detrás del contenido de un elemento HTML */

.progress-bar .step:last-child .bullet:before,
.progress-bar .step:last-child .bullet:after{
    display: none;
}
.progress-bar .step .bullet:before,
.progress-bar .step .bullet:after {
    position: absolute;
    content: "";
    bottom: 11px;
    right: -51px;
    height: 3px;
    width: 44px;
    background: #262626 ;
}
.progress-bar .step .bullet.active:after {
    background: #DAF7A6;
    transform: scaleX(0);
    transform-origin: left;
    animation: animate 0.3s linear forwards;
}

/* Resaltemos que la regla @keyframes permite construir animaciones, a partir de un elemento con 
transición */
@keyframes animate{
    100% {
        transform: scaleX(1);
    }
}

.progress-bar .step .bullet span {
    font-weight: 500;
    font-size: 17px;
    line-height: 25px;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}
.progress-bar .step .bullet.active span {
    display: none;
}
.progress-bar .step .check {
    position: absolute;
    left: 50%;
    top: 70%;
    font-size: 15px;
    transform: translate(-50%, -50%);
    display: none;
}
.progress-bar .step .check.active {
    display: block;
    color: #fff;
} 
/**/