body {
    font-family: Arial, "文泉驛正黑", "WenQuanYi Zen Hei", "微軟正黑體", "Microsoft JhengHei", "標楷體", DFKai-SB, sans-serif;
}

.btn-goDown {
    max-width: 150px;
    cursor: pointer;
}

.m-center {
    margin-left: auto;
    margin-right: auto;
}

.h-100 { height: 100%; }

#btn-side-top {
    max-width: 50px;
    position: fixed;
    bottom:20px;
    right:7%;
    opacity: 0.7;
    transition: opacity 0.5s;
    z-index: 1000;
}
#btn-side-top:hover {
    opacity: 1;
}