.must-icon{
    position: relative;
}
.must-icon::before {
	content: "必須";
    display: inline-block;
	color: #fff;
    background-color: #b92222;
	padding: 0.1rem 0.8rem;
    margin-right: 0.4rem;
	font-size: 0.7rem;
    vertical-align: text-top;
}

.btn-active{
    box-shadow: 3px 3px 3px rgb(0 0 0 / 20%);
}

.btn-active::before{
    display: block;
    position: absolute;
    z-index: 2;
    left: -30%;
    top: -50%;
    content: "";
    width: 50px;
    height: 200px;
    transform: rotate(30deg);
    background-image: linear-gradient(to left, rgba(255, 255, 255, 0) 0%, white 50%, rgba(255, 255, 255, 0) 100%);
    -webkit-animation: activeButton 3s infinite linear;
    animation: activeButton 3s infinite linear;
}

.slide-next::after{
    content: '';
    position: absolute;
    top: 50%;
    right: 11px;
    display: block;
    width: 8px;
    height: 8px;
    border-top: 1px solid;
    border-right: 1px solid;
    border-color: #fff;
    transform: translateY(-50%) rotate(45deg);
}

@keyframes activeButton {
    0% {
        left: -30%;
    }
    20% {
        left: 100%;
    }
    100% {
        left: 100%;
    }
}