.otc {
    position: relative;
    width: 0px;
    margin: 0 auto;
}

.otc fieldset {
    border: 0;
    padding: 0;
    margin: 0;
}

.otc fieldset div {
    display: flex;
    align-items: center;
    justify-content: center
}

.otc button {
    position: absolute;
    left: -100px;
}

.otc .alert {
    width: 500px;
    position: relative;
    left: -250px;
}
input[type="number"] {
    width: .86em;
    line-height: 1;
    margin: .1em;
    padding: 8px 0 4px;
    font-size: 2.65em;
    text-align: center;
    appearance: textfield;
    -webkit-appearance: textfield;
    border: 0;
    border-radius: 6px;
}

input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

/* 2 groups of 3 items */
input[type="number"]:nth-child(n+4) {
    order: 2;
}
.otc div::before {
    content: '';
    height: 2px;
    width: 12px;
    margin: 0 .25em;
    order: 1;
    background: #fff;
    border-radius: 2px;
    opacity: .4;
}

/* From: https://gist.github.com/ffoodd/000b59f431e3e64e4ce1a24d5bb36034 */
.otc label {
    border: 0 !important;
    clip: rect(1px, 1px, 1px, 1px) !important;
    -webkit-clip-path: inset(50%) !important;
    clip-path: inset(50%) !important;
    height: 1px !important;
    margin: -1px !important;
    overflow: hidden !important;
    padding: 0 !important;
    position: absolute !important;
    width: 1px !important;
    white-space: nowrap !important;
}

.storeLink {
    position: relative;
    display: inline-block;
    width: 150px;
    height: 50px;
    border-radius: 16px;
    overflow: hidden;
    background-color: black;
}
.storeLink > img {
    --width: 100%;
    position: absolute;
    width: var(--width);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}