* {
    padding: 0;
    margin: 0;
}
html,
body {
    width: 100%;
    height: 100%;
    box-sizing: border-box;
    overflow: hidden;
}
.activity {
    position: relative;
    width: 100%;
    height: 100%;
    overflow-y: auto;
}
.activity::-webkit-scrollbar {
    width:0;
}
.activity img {
    width: 100%;
    display: block;
}