body,
html {
    font-size: 16px;
    color: #555;
    line-height: 1.3em;
}

body,
input,
textarea {
    font-family: Arial, Helvetica, sans-serif, "Microsoft JhengHei";
}

body{
    background-color: #555;
}

.container{
    max-width: 960px;
    margin: 0 auto;
    position: relative;
}

.image_container{
    position: relative;
}

img{
    display: block;
    width: 100%;
}

.image_container{
    display: block;
    width: 100%;
}

.btn{
    display: block;
    position: absolute;
    right: 3%;
    top: 2%;
    z-index: 100;
    width: 10%;
    /* background-image: url(../images/backtop.png);
    background-size: contain; */
}

.btn:hover{
    /* background-image: url(../images/backtop_2.png); */
    filter: brightness(0.7);
}

