Criei dois arquivos nomeados de "header.html" e "menu_lateral.html", contendo, respectivamente, os trechos de código a seguir:
{% load static %}
<header class="cabecalho">
<img src="{% static '/assets/logo/Logo(2).png' %}" alt="Logo da Alura Space" />
<div class="cabecalho__busca">
<div class="busca__fundo">
<input class="busca__input" type="text" placeholder="O que você procura?">
<img class="busca__icone" src="{% static '/assets/ícones/1x/search.png' %}" alt="ícone de search">
</div>
</div>
</header>{% load static %}
<section class="menu-lateral">
<nav class="menu-lateral__navegacao">
<a href="{% url 'index' %}"><img src="{% static '/assets/ícones/1x/Home - ativo.png' %}"> Home</a>
<a href="#"><img src="{% static '/assets/ícones/1x/Mais vistas - inativo.png' %}"> Mais vistas</a>
<a href="#"><img src="{% static '/assets/ícones/1x/Novas - inativo.png' %}"> Novas</a>
<a href="#"><img src="{% static '/assets/ícones/1x/Surpreenda-me - inativo.png' %}"> Surpreenda-me</a>
</nav>
</section>Reorganizei o arquivo "base.html" para incluir as duas "partials" criadas:
{% load static %}
<!DOCTYPE html>
<html lang="pt-br">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Alura Space</title>
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link href="https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600&display=swap" rel="stylesheet">
<link rel="stylesheet" href="{% static '/styles/style.css' %}">
</head>
<body>
<div class="pagina-inicial">
{% include 'galeria/partials/_header.html' %}
<main class="principal">
{% include 'galeria/partials/_menu_lateral.html' %}
{% block content %}{% endblock %}
</main>
{% include 'galeria/partials/_footer.html' %}
</div>
</body>
</html>