.b-logo {
    width: 8.1rem
}

@media only screen and (max-width: 987px) {
    .b-logo {
        width: 5rem
    }
}

.b-logo a {
    position: relative;
    display: inline-block;
    padding-bottom: 50%;
    width: 100%;
    height: 0;
    color: inherit
}

.b-logo a:hover {
    color: inherit
}

.b-logo a:after {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--color-white);
    content: "";
    -webkit-mask: url("../images/logo/logo-head.png") no-repeat center/contain;
    mask: url("../images/logo/logo-head.png") no-repeat center/contain;
    mask-mode: alpha
}