<html>
<head>
<style>
::file-selector-button {
border: 2px solid black;
padding: 5px 10px;
border-radius: 5px;
background-color: lightgreen;
}
::file-selector-button:hover {
background-color: salmon;
cursor: pointer;
}
</style>
</head>
<body>
<h1>Demo of ::file-selector-button</h1>
<form>
<label for="fileUpload">Upload file: </label>
<input type="file" id="fileUpload" />
</form>
</body>
</html>