To debug the HTML webpage, you can check which file the corresponding attribute is set in through the browser F12, so it is easier to find the corresponding style file, and then modify it on the corresponding basis, as shown below:
Then you can find the corresponding style file according to the html code path:
<!-- CSS -->
<link rel="stylesheet" href="assets/bootstrap/css/bootstrap.min.css">
<link rel="stylesheet" href="assets/font-awesome/css/font-awesome.min.css">
<link rel="stylesheet" href="assets/css/animate.css">
<link rel="stylesheet" href="assets/css/magnific-popup.css">
<link rel="stylesheet" href="assets/flexslider/flexslider.css">
<link rel="stylesheet" href="assets/css/form-elements.css">
<link rel="stylesheet" href="assets/css/style.css">
<link rel="stylesheet" href="assets/css/language.css">Use "debugger" to set breakpoints in html.