@charset "UTF-8";

.box {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap
}

header {
    width: 100%;
    height: 0;
    padding-bottom: 34%;
	background-color: aquamarine;
	background-image: url("../image/top-bach.webp");
	background-repeat: no-repeat;
    background-position: center;
	background-size:cover;
    position: relative;
}

header h1 {
	/* text-align: center; */
	font-size: 38px;
	color: #fff;
	text-shadow: 2px 2px 2px darkslateblue, -2px 2px 2px darkslateblue, 2px -2px 2px darkslateblue, -2px -2px 2px darkslateblue;
    position: absolute;
    top:50%;
    left: 50%;
    transform: translate(-50%,-50%);
    /* position:relative; */
    /* top: 50%; */
}
main {
	max-width: 960px;
	width: 100%;
	margin: 0 auto;
	padding: 20px;
	flex: 1;
}
main figure{
    text-align: center;
}
main figure img{
    max-width: 100%;
}
.item {
    box-sizing: border-box;
    width: calc(100%/4 - 10px);
    /*	border: 1px solid #000;*/
    border-radius: 8px;
    box-sizing: border-box;
    padding-top: calc(75%/4 - 40px);
    background-repeat: no-repeat;
    background-size: cover;
    margin-bottom: 1em;
}

.schedule {
    background-image: url(../image/top01.jpg);
}

.report {
    background-image: url(../image/top02.jpg);
}

.post {
    background-image: url(../image/top03.jpg);
}

.meeting {
    background-image: url(../image/top04.jpg);
}

.tech {
    background-image: url(../image/top05.jpg);
}

.member {
    background-image:
        url(../image/top06.jpg);
}
.study {
    background-image:
        url(../image/top08.jpg);
}

.archives {
    background-image:
        url(../image/top07.jpg);
}

.preparate {
    background-image:
        url(../image/top4.jpg);
}

.record {
    background-image:
        url(../image/top5.jpg);
}

.usage {
    background-image:
        url(../image/top6.jpg);
}

.up {
    background-image:
        url(../image/top7.jpg);
}

.ch9 {
    background-image:
        url(../image/top8.jpg);
}

.ch10 {
    background-image:
        url(../image/top9.jpg);
}

.ch11 {
    background-image:
        url(../image/top10.jpg);
}

h2 {
    margin-top: -40%;
    text-shadow: 2px 2px 2px #fff, -2px 2px 2px #fff, 2px -2px 2px #fff, -2px -2px 2px #fff;
    font-size: 30px;
    text-align: center
}

.item h2 a {
    text-decoration: none;
    color: blue;
    display: block;
}
ul.nav{
    margin: 0;
    padding: 0;
    list-style-type: none;
    text-align: center;
}

ul.nav li{
    display: inline-block;
}
@media screen and (max-width:640px){
    .item {
        width: calc(100%/2 - 10px);
        padding-top: calc(100%/4 );
    }
}