.dropdown__lists {
    display: none;/*デフォルトでは非表示の状態にしておく*/
    width:30%;
    position: absolute;
    top: 30px;
    left: 0;
}
.gnavi__list:hover .dropdown__lists {
    display: block;/*Gナビメニューにホバーしたら表示*/
}
.dropdown__list {
    background-color: #004d80;
    height: 30px;
    transition: all .3s;
    position: relative;
}
.dropdown__list:not(:first-child)::before{
    content: "";
    width: 50%;
    height: 1px;
    background-color: #3492d1;
    position: absolute;
    top: 0;
    left: 0;
}
.dropdown__list:hover {
    background-color: #003558;
}
.dropdown__list a {
    display: flex;
    justify-content: left;
    align-items: center;
    color: #fff;
    text-decoration: none;
    position: relative;
}
.dropdown__list a::before {
    content: '';
    display: block;
    width: 6px;
    height: 6px;
    border-top: 2px solid #fff;
    border-left: 2px solid #fff;
    transform: rotate(135deg);
    position: absolute;
    right: 15px;
    top: calc(50% - 5px);
}