背景固定(スマホ)さらなる今更感
body::before {
background: url('img/mainbg_sp.png') no-repeat center;
background-size: cover;
content: "";
display: block;
position: fixed;
width: 100%;
height: 100vh;
top: 0;
left: 0;
z-index: -1;
}
body::before {
background: url('img/mainbg_sp.png') no-repeat center;
background-size: cover;
content: "";
display: block;
position: fixed;
width: 100%;
height: 100vh;
top: 0;
left: 0;
z-index: -1;
}