HTMLify

html {
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
}

* {
    box-sizing: inherit;
}

*:before,
*:after {
    box-sizing: inherit;
}

body {
    min-height: 100vh;
    display: flex;
    font-family: "Roboto", Arial;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    background: #0D0F18;
}

.button {
    --color: #fff;
    --background: #a958ff;
    --height: 41px;
    --width: 160px;
    --icon: #fff;
    padding: 0;
    cursor: pointer;
    text-align: center;
    position: relative;
    border: none;
    outline: none;
    background: none;
    appearance: none;
    -webkit-tap-highlight-color: transparent;
    width: var(--width);
    letter-spacing: 0.5px;
    font-size: 14px;
    font-weight: 700;
    color: var(--color);
    line-height: var(--height);
}

.button::before,
.button::after {
    content: "";
    display: block;
    position: absolute;
    top: 50%;
    left: 50%;
}

.button::before {
    transform: translate(-50%, -50%);
    width: var(--before-w, var(--width));
    height: var(--before-h, var(--height));
    border-radius: var(--before-r, 7px);
    background: var(--background);
    transform-origin: 50% 50%;
    transition: width 0.3s, height 0.3s, border-radius 0.2s;
    transition-delay: 0.2s;
}

.button::after {
    width: 16px;
    height: 16px;
    margin: -8px 0 0 -8px;
    background: var(--icon);
    z-index: 2;
    border-radius: 50%;
    transform: scale(0);
}

.button span {
    z-index: 1;
    display: block;
    position: relative;
    opacity: var(--span-o, 1);
    transform: scale(var(--span-s, 1));
    transition: opacity 0.3s, transform 0.2s;
    transition-delay: 0.2s;
}

.button svg {
    width: 15px;
    height: 13px;
    display: block;
    position: absolute;
    left: 50%;
    top: 50%;
    stroke: var(--icon);
    stroke-width: 2px;
    stroke-linecap: round;
    stroke-linejoin: round;
    fill: none;
    transform: translate(-50%, -50%);
    stroke-dasharray: 17px;
    stroke-dashoffset: var(--svg-o, 17px);
    transition: stroke-dashoffset 0.3s ease;
}

.button.processing {
    --before-w: 41px;
    --before-h: 41px;
    --before-r: 22px;
    --span-o: 0;
    --span-s: .6;
    --after-s: 1;
    --svg-o: 34px;
}

.button.processing::before {
    animation: pulse 3s linear forwards;
}

.button.processing::after {
    animation: dot 3s linear forwards;
}

.button.processing svg {
    transition-delay: 3s;
}

@keyframes pulse {
    4% {
        transform: translate(-50%, -50%) scaleX(1.1);
    }

    8% {
        transform: translate(-50%, -50%);
    }

    24%,
    56%,
    88% {
        transform: translate(-50%, -50%) scale(0.8);
    }

    40%,
    72% {
        transform: translate(-50%, -50%) scale(1.2);
    }
}

@keyframes dot {
    8% {
        transform: scale(0);
    }

    16% {
        transform: scale(1) rotate(30deg) translateX(48px);
    }

    95% {
        transform: scale(1) rotate(1000deg) translateX(48px);
    }

    100% {
        transform: scale(0.125) rotate(1050deg) translate(52px, -6px);
    }
}