*{
    border: 0;
    padding: 0;
    margin: 0;
}

#index{
    width: 100%;
    height: 100vh;
    display: flex;
    overflow: hidden;
    position: relative;
    background-color: rgba(253,249,240, 0.5);
}
#index video{
    width: 100%;
    position: absolute;
    top: 0;
    left: 0;
}
#left{
    width: 0.95rem;
    height: 100vh;
}
#middle{
    width: 2.65rem;
    height: 100vh;
}
.middle-menu{
    width: 4.5rem;
    height: 4.8rem;
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 3.05rem;
    left: 7.54rem;
    /* background-color: white; */
}
.middle-menu .title{
    display: block;
    height: 0.65rem;
}
.middle-menu .title-text{
    margin-top: 0.45rem;
    font-size: 0.20rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: #333;
}
.middle-nav{
    margin-top: 0.4rem;
    height: 8rem;
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    align-items: center;
    font-size: 0.28rem;
    font-weight: 500;
}
.middle-nav li{
    width: 100%;
    display: flex;
    justify-content: center;
    background-size: contain;
}
.middle-nav li.midddle-active{
    background: url("../img/selected.png") no-repeat;
    background-position-x: 50%;
    background-position-y: 50%;
}
.middle-nav a{
    text-decoration: none;
    color: black;
    padding-bottom: 0.2rem;
}
.tree{
    display: block;
    width: 8.6rem;
    position: absolute;
    top: -0.8rem;
    right: 0;
    z-index: 10;
}
#nav{
    width: 2.65rem;
    height: 100vh;
    position: fixed;
    top: 0;
    left: 0.95rem;
    z-index: 1;
    background-color: white;
    /* opacity: 0.6; */
}
#right{
    width: 15.6rem;
    display: flex;
    justify-content: flex-end;
    align-items: center;
}
#right img{
    width: 100%;
}

.master{
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    background-color: rgba(253,249,240, 0.5);
}