/* “§‰ßƒŠƒ“ƒN */
.opacityText{
    position: relative;
    margin: 12px 0;
}

.opacityText span.mask{
    position: relative;
    transition: .3s ease-in-out;
    display: block;
    line-height: 0;
}

.opacityText:hover span.mask::before{
    content:"";
    position: absolute;
    z-index:2;
    top:0;
    left:0;
    width: 100%;
    height: 100%;
    background: linear-gradient(-45deg, rgba(0, 184, 238, .6),
            rgba(155, 201, 84, .6),
            rgba(47, 89, 162, .6),
            rgba(247, 181, 44, .6));
}

.opacityText img{
    opacity:1;
    transition: .3s ease-in-out;
}

.opacityText:hover img{
    opacity:0.6;
}

.opacityText span.cap{
    opacity:0;
    transition: .5s ease-in-out;
    position: absolute;
    z-index:3;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    color: #fff;
    font-size: 1.1rem;
    font-weight: bold;
    line-height: 1.5;
}

.opacityText:hover span.cap{
    opacity:1;
}

/* footer */
footer {
    padding-top: 30px;
    background-color: #f2f2f2;
    text-align: center;
}

.footer-gallery {
    margin: 80px 50px 30px 50px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-gallery img {
    width: 100%;
}

.footer-box1 {
    width: 31%;
    height: 31%;
}

.footer-box2,.footer-box3,.footer-box4 {
    width: 22%;
}

.gallery{
    columns: 4;
    padding:0 15px;
    margin:0;
}

.gallery li {
    margin-bottom: 20px;
    list-style:none;
}

.gallery img{
    width:100%;
    height:auto;
    vertical-align: bottom;
}

#copyright {
    font-weight: bold;
    margin-top: 10px;
}

.footer-rikunabi {
    margin-bottom: 20px;
}

.footer-rikunabi p {
    font-size: .9rem;
}

@media only screen and (max-width: 960px) {
    .footer-gallery {
        margin: 80px 10px 30px 10px;
    }
}

@media only screen and (max-width: 640px) {
    .footer-box1 {
        width: 57%;
    }
    .footer-box2 {
        width: 39%;
    }
    .footer-box3,.footer-box4 {
        width: 48%;
    }
    .footer-gallery {
        flex-wrap: wrap;
    }
}