要为<select>中的选项设置样式，您可以尝试运行以下代码，
<!DOCTYPE html>
<html>
<head>
<style>
select {
width: 100%;
padding: 10px 15px;
border: 1px dashed blue;
border-radius: 4px;
background-color: orange;
}
</style>
</head>
<body>
<p>Learn,</p>
<form>
<select id = "country" name = "country">
<option value = "java">Java</option>
<option value = "ruby">Ruby</option>
<option value = "oracle">Oracle</option>
<option value = "tableau">Tableau</option>
</select>
</form>
</body>
</html>