src/views/layouts/main.php
<html lang="ru">
<head>
<title>@page.title</title>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
@page.head
</head>
<body>
@page.content
@page.footer
</body>
</html>