styles.css

.gauge {
    position: relative;
    height: 16rem;
    width: 0.5rem;
    background: rgb(203 213 225);
}
.gauge__progress {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    background: rgb(99 102 241);
}
.gauge__tick {
    position: absolute;
    left: 100%;
    width: 0.5rem;
    height: 1px;
    background: rgb(203 213 225);
}
.gauge__tick--minor {
    width: 0.25rem;
}
.gauge__label {
    position: absolute;
    left: 50%;
    transform: translate(0.5rem, -50%);
}
.gauge__marker {
    position: absolute;
    top: -0.5rem;
    left: 0;
    width: 0.5rem;
    height: 1rem;

    cursor: move;
    user-select: none;
    touch-action: none;
}
.gauge__marker::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    transform: translateX(-100%);

    border-style: solid;
    height: 0;
    width: 0;

    border-color: transparent transparent transparent rgb(99 102 241);
    border-width: 0.5rem 0 0.5rem 0.5rem;
}