.frame {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 400px;
    height: 400px;
    margin-top: -200px;
    margin-left: -200px;
    border-radius: 2px;
    box-shadow: 1px 2px 10px 0px rgba(0, 0, 0, 0.3);
    background: rgb(246, 232, 215);
    background: -moz-radial-gradient(center, ellipse cover, rgba(246, 232, 215, 1) 0%, rgba(218, 190, 155, 1) 100%);
    background: -webkit-radial-gradient(center, ellipse cover, rgba(246, 232, 215, 1) 0%, rgba(218, 190, 155, 1) 100%);
    background: radial-gradient(ellipse at center, rgba(246, 232, 215, 1) 0%, rgba(218, 190, 155, 1) 100%);
    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#f6e8d7', endColorstr='#dabe9b', GradientType=1);
    overflow: hidden;
}

.floor {
    position: absolute;
    top: 244px;
    left: 0;
    right: 0;
    bottom: 0;
    background: #232323;
}

.invisible-men {
    animation: fade-in .8s ease-out 1s;
    animation-fill-mode: both;
}

.leg {
    position: absolute;
    top: 0px;
    left: 147px;
    width: 151px;
    height: 245px;
    transform-origin: 50% 0;
}

.shoe {
    position: absolute;
    width: 151px;
    height: 128px;
    left: 0;
    bottom: 0;
    background: url('https://100dayscss.com/codepen/doc-martens.svg') center center no-repeat;
    transform-origin: 0 95%;
}

.left {
    animation: leg-swing 2s ease-in-out infinite;

    .shoe {
        animation: shoe-turn 2s ease-in-out infinite;
    }
}

.right {
    animation: leg-swing 2s ease-in-out 1s infinite;

    .shoe {
        animation: shoe-turn 2s ease-in-out 1s infinite;
    }
}

@keyframes leg-swing {

    0%,
    100% {
        transform: rotate(-22deg);
    }

    50% {
        transform: rotate(40deg);
    }
}

@keyframes shoe-turn {

    0%,
    100% {
        transform: rotate(-10deg) translateY(-5px) translateX(10px);
    }

    25% {
        transform: rotate(0deg) translateY(0px) translateX(0);
    }

    50% {
        transform: rotate(10deg) translateY(-10px) translateX(10px);
    }

    75% {
        transform: rotate(0deg) translateY(-30px) translateX(0);
    }
}

@keyframes fade-in {
    0% {
        opacity: 0;
    }

    100% {
        opacity: 1;
    }
}