Submitted solutions for "007 World"

@keyframes leftRight {
        from { transform: translate(-50%, -50%) translate(-3em, 0); }
        to { transform: translate(-50%, -50%) translate(3em, 0); }
}

.box {
        background-color: #000;
        color: #fff;
}

.box::before {
        content: 'Hello World';
}

.box::after {
        content: '';

        position: absolute;
        left: 50%; top: 50%;

        width: 1.5em;
        height: 1.5em;
        border-radius: 100%;

        background-color: #fff;
        mix-blend-mode: difference;

        animation: leftRight 3s linear infinite;
        animation-direction: alternate;
}

.box {
        background: #000;
        color: #fff;
}
.box:before, .box:after {
        position: absolute;
        content: "Hello World"
}

@keyframes derp {
        0%, 100% {
                clip-path: circle(20px at 15% 50%);
        }
        50% {
                clip-path: circle(20px at 82% 50%);
        }
}

.box:after {
        color: #000;
        background: #fff;
        padding: 20px;
        animation-iteration-count: infinite;
    animation-name: derp;
    animation-duration: 6s;
    animation-timing-function: linear;
}