/* 形のレイアウト */
.openbtn{
    position: relative;
    cursor: pointer;
    width: 50px;
    height: 50px;
    background-color: #fff;
    opacity: 0.8;
}
  
.openbtn span{
    display: inline-block;
    transition: all .4s;
    position: absolute;
    left: 14px;
    height: 2px;
    border-radius: 5px;
    background: #3ca6ce;
    width: 45%;
}

.openbtn p{
    padding: 0;
}

.nav_menu{
    position: absolute;
    font-size: 10px;
    color: #3ca6ce;
    font-weight: bold;
    left: 9px;
    top: 30px;
    transition: 1s;
}

.nav_close{
    position: absolute;
    font-size: 10px;
    color: #3ca6ce;
    font-weight: bold;
    left: 8px;
    top: 30px;
    opacity: 0;
    transition: 1s;
}

.openbtn span:nth-of-type(1) {
    top:13px; 
}

.openbtn span:nth-of-type(2) {
    top:19px;
}

.openbtn span:nth-of-type(3) {
    top:25px;
}

/*クリックしたときのボタンの動き*/ 
.openbtn.active span:nth-of-type(1) {
    -webkit-transform: translateY(4px) rotate(-315deg);
}

.openbtn.active span:nth-of-type(2) {
    opacity: 0;
}

.openbtn.active span:nth-of-type(3) {
    -webkit-transform: translateY(-8px) rotate(315deg);
}
  
.openbtn.active .nav_menu{
    opacity: 0;
}

.openbtn.active .nav_close{
    opacity: 1;
}

/*配置のレイアウト*/
header{
    position: relative;
}

.openbtn{
    position: fixed;
    right: 0px;
    top: 3px;
    z-index: 100;
}

/* メニューのレイアウト */
.nav_hamburgermenu{
    box-sizing: border-box;
    position: absolute;
    position: fixed;
    top: 0px;
    right: -100%;
    width: 100%;
    height: 100%;
    padding: 20px 10px 0;
    background-color: #eff3f6;
    text-align: center;
    transition: right 0.5s;
    font-weight: bold;
    opacity: 0.9;
    z-index: 10;
}
  
.nav_hamburgermenu.open{
    right: 0;
}

.nav_hamburgermenu_menu{
    height: 50%;
    display: flex;
    flex-flow: column;
    justify-content:space-around;
}

.nav_hamburgermenu_menu li{
    position: relative;
    list-style: none;
}


.nav_hamburgermenu_menu a{
    color: #3ca6ce;
    text-decoration: none;
}

body{
    overflow-x: hidden;
}

/*  640px以上 */
@media (min-width:640px) {
    .hamburgermenu{
        display: none;
    }
    
    .openbtn{
        position: fixed;
        right: 0px;
        top: 0px;
        z-index: 10;
        border-radius: 0;
    }

    .nav_hamburgermenu{
        width: 30%;
        height: 100%;
        transition: right 0.7s;
    }
}