This chapter introduces how to implement a back-to-top effect for web pages using JS/CSS.
CSS Button Styles:
#myBtn {
display: none; /*Hidden by default*/
position: fixed;
bottom: 20px;
right: 30px;
z-index: 99;
border: none;
outline: none;
background-color: red; /*Set the background color. You can set the color or image you want.*/
color: white; /*Text color*/
cursor: pointer;
padding: 15px;
border-radius: 10px; /*Rounded corners*/
}
#myBtn:hover {
background-color: #555;
}
JS Code:
//The "Back to Top" button appears when the page scrolls down 20px.
window.onscroll = function() {scrollFunction()};
function scrollFunction() {console.log(121);
if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) {
document.getElementById("myBtn").style.display = "block";
} else {
document.getElementById("myBtn").style.display = "none";
}
}
//Click the button to return to the top.
function topFunction() {
document.body.scrollTop = 0;
document.documentElement.scrollTop = 0;
}
Try it »