* {
    -webkit-box-sizing: border-box;
    box-sizing: border-box;
    padding: 0;
    margin: 0
}

body,
html {
    width: 100%
}

.app {
    width: 100%;
    height: 100vh;
    padding-top: 5px;
    background-image: url(bg.jpg);
    background-position: center;
    background-size: cover;
    background-repeat: no-repeat;
    position: relative
}

.overlay {
    width: 100%;
    height: 100vh;
    background: #000;
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0;
    -webkit-animation: back .5s ease;
    animation: back .5s ease;
    -webkit-animation-fill-mode: forwards;
    animation-fill-mode: forwards;
    -webkit-animation-delay: .4s;
    animation-delay: .4s
}

.main {
    width: 60%;
    position: absolute;
    left: 20%;
    top: 20%;
    opacity: 0;
    -webkit-animation: show .5s ease;
    animation: show .5s ease;
    -webkit-animation-fill-mode: forwards;
    animation-fill-mode: forwards;
    -webkit-animation-delay: 1s;
    animation-delay: 1s
}

.main .main-wrapper {
    position: relative;
    width: 100%
}

.main .main-wrapper img {
    width: 100%;
}

.bg {
    border-radius: 15px;
}

.main .main-wrapper .btn {
    width: 30%;
    position: absolute;
    left: 52%;
    top: 66%;
    -webkit-animation: btn 1s linear;
    animation: btn 1s linear;
    -webkit-animation-iteration-count: infinite;
    animation-iteration-count: infinite
}

.main .main-wrapper .btn .btn-wrapper {
    width: 100%;
    height: 100%;
    position: relative
}

.main .main-wrapper .btn .btn-wrapper img {
    width: 100%
}

@-webkit-keyframes back {
    form {
        opacity: 0
    }
    to {
        opacity: .7
    }
}

@keyframes back {
    form {
        opacity: 0
    }
    to {
        opacity: .3
    }
}

@-webkit-keyframes show {
    from {
        opacity: 0;
        -webkit-transform: translateY(-10%);
        transform: translateY(-10%)
    }
    to {
        opacity: 1;
        -webkit-transform: translateY(0);
        transform: translateY(0)
    }
}

@keyframes show {
    from {
        opacity: 0;
        -webkit-transform: translateY(-10%);
        transform: translateY(-10%)
    }
    to {
        opacity: 1;
        -webkit-transform: translateY(0);
        transform: translateY(0)
    }
}

@-webkit-keyframes btn {
    from {
        -webkit-transform: scale(1, 1);
        transform: scale(1, 1)
    }
    50% {
        -webkit-transform: scale(1.1, 1.1);
        transform: scale(1.1, 1.1)
    }
    to {
        -webkit-transform: scale(1, 1);
        transform: scale(1, 1)
    }
}

@keyframes btn {
    from {
        -webkit-transform: scale(1, 1);
        transform: scale(1, 1)
    }
    50% {
        -webkit-transform: scale(1.1, 1.1);
        transform: scale(1.1, 1.1)
    }
    to {
        -webkit-transform: scale(1, 1);
        transform: scale(1, 1)
    }
}