I'm starting with materialize and obviously I'm a novice, the problem I have is that although in my code I have a margin: 0 puts me one on the top, and is out of any container and row ... How do I remove that margin? of my background? So it looks ...
.fondo_cabecera{
height: 860px;
background-color:red;
margin:0;
}
<!DOCTYPE html>
<html lang="es">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css">
<link rel="stylesheet" href="estilos.css">
<title>Landing Page</title>
</head>
<body>
<header class="fondo_cabecera">
<div class="container">
<h1 class="white-text">Hola Mundo</h1>
</div>
</header>
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/js/materialize.min.js"></script>
</body>
</html>