#backTop {
    position: fixed;
    bottom: 60px;
    right: 2px;
    z-index: 9999;
    text-align: center;
    text-transform: uppercase;
    cursor: pointer;
    text-decoration: none;
    transition: opacity 0.2s ease-out;
    opacity: 0;
    border: 1px solid #797979;
    border:none;
}

#backTop span {
    color: #453c3c;
    display: block;
    font-weight: 900;
}

#backTopimg:hover{
    opacity: 0.8 !important;
}

#backTop.show {
    opacity: 1;
}

@media (max-width: 500px) {
    #backTop.show {
        display: block;
    }
}

.snowEffect {
position: fixed;
width: 100%;
height: 100%;
left: 0;
top: 0;
z-index: 99;
overflow: hidden;
pointer-events:none; /*Không có dòng này là ko click đc các phần tử khác*/
}
#snowcanvas{
position: fixed;
z-index: 0;
}