#mainBox{
    width: 810px;
    height:690px;
    margin:auto;
    margin-top: 35px;
    background-color: aquamarine;
    display: flex;
    flex-direction: row;
    transition: background-color 0.3s, width 0.3s;
    border-radius: 30px;
}

#displayBox{
    width: 460px;
    height: 630px;
    margin-left: auto;
    margin-top: 15px;
    background-color: aqua;
    border: 15px solid white;
    border-radius: 40px;
    box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
    z-index:2;
    transition: background-color 0.3s, width 0.3s;
    /*overflow-y: scroll;*/
}

#contentBoxA{
    width: 425px;
    height: 600px;
    margin-left: 15px;
    margin-top: 15px;
    background-color: white;
    border-radius: 15px;
    z-index:2;
    transition: background-color 0.3s, width 0.3s, margin-left 0.3s ;
    /*overflow-y: scroll;*/
}

#contentBoxB{
    width: 425px;
    height: 600px;
    margin-left: 15px;
    margin-top: 15px;
    background-color: white;
    border-radius: 15px;
    z-index:2;
    transition: background-color 0.3s, width 0.3s, margin-left 0.3s ;
    display:none;
}

/***********************************************************/

#menuList{
    display: flex;
    flex-direction: column;
    margin-top: auto;
    margin-bottom: auto;
    margin-right: auto;
    margin-left: -6.5px;
}

.menuOption{
    float: right;
    width: 225px;
    height: 65px;
    margin: -7.5px;
    display: table-column;
    background-color: rgb(0, 219, 219);
    border-style: solid solid solid none;
    border-radius: 40px;
    border-bottom-left-radius: 0;
    border-top-left-radius: 0;
    border-color: rgb(48, 150, 150);
    border-width: 15px;
    z-index:0;
    text-align: center;
    line-height: 65px;
    user-select: none; 
    transition: background-color 0.07s, border-color 0.07s;
    color: rgb(48, 150, 150);
    text-shadow: 0px 0px 2px rgba(0, 0, 0, 0.2);
    font-size: 25px;
    font-family: "Russo One", sans-serif;
    font-weight: 400;
    font-style: normal;
}

.activeMenu{
    border-color: white;
    background-color: aqua;
    z-index:4;
    color: white;
    text-shadow: 0px 0px 3px rgba(0, 0, 0, 0.2);
    font-size: 30px;
    font-family: "Russo One", sans-serif;
    font-weight: 400;
    font-style: normal;
}

.menuOption:hover:not(.activeMenu){
    background-color: rgb(0, 185, 209);
    z-index: 1;
    box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
}

.activeMenu:hover{
    background-color: white;
    transition: background-color 0.3s, box-shadow 0.3s;
}

.selectedMenu:not(.activeMenu){
    background-color: rgb(0, 185, 209);
    z-index: 1;
    box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
}

@keyframes selectedActive {
    0% {background-color: white;}
    100% {background-color:  aqua;}
}

.selectedMenu.activeMenu{
    background-color: aqua;
    animation-name: selectedActive;
    animation-duration: 1s;
}