expenses_manager/.env.example

@@ -0,0 +1,17 @@
+# Django
+DEBUG=True
+SECRET_KEY=genera-una-clave-aqui
+
+# Hosts (separados por comas). En producción, tu dominio real.
+ALLOWED_HOSTS=localhost,127.0.0.1
+CSRF_TRUSTED_ORIGINS=
+
+# Base de datos.
+# En local puedes dejar DB_ENGINE vacío o en sqlite3 para usar SQLite sin más.
+# Para PostgreSQL, pon DB_ENGINE=postgresql y rellena el resto.
+DB_ENGINE=sqlite3
+DB_NAME=
+DB_USER=
+DB_PASSWORD=
+DB_HOST=localhost
+DB_PORT=5432

expenses_manager/expenses/forms.py

@@ -122,15 +122,15 @@ class GoalForm(forms.ModelForm):
     class Meta:
         model = Goal
         fields = [
-            'name',
+            "name",
-            'kind',
+            "kind",
-            'target_amount', 
+            "target_amount",
-            'category',  
+            "category",
             "include_subcategories",
             "account",
             "start_date",
             "period",
-            "show_on_home"
+            "show_on_home",
         ]
         widgets = {
             "start_date": forms.DateInput(

expenses_manager/expenses/models.py

@@ -5,7 +5,6 @@ from django.conf import settings
 from django.db.models import Sum
 from functools import cached_property
 from django.utils.text import slugify
-from django.db.models.fields import related
 from django.db.models.functions import ExtractMonth
 
 

expenses_manager/expenses/static/expenses/js/charts.js

@@ -0,0 +1,88 @@
+(function () {
+    function getActiveTheme() {
+        return document.documentElement.getAttribute('data-theme') === 'dark' ? 'dark' : 'light';
+    }
+
+    function getChartColors() {
+        var styles = getComputedStyle(document.documentElement);
+        var theme = getActiveTheme();
+    
+        return {
+            theme: theme,
+            gridColor: styles.getPropertyValue('--chart-grid-color').trim() || 'rgba(0, 0, 0, 0.1)',
+            tickColor: styles.getPropertyValue('--color-text-muted').trim() || '#6b6560',
+            primaryColor: styles.getPropertyValue('--color-primary').trim() || '#0f766e',
+            primaryFill: styles.getPropertyValue('--chart-fill-color').trim() || 'rgba(15, 118, 110, 0.2)',
+            palette: ['#ff6384', '#36a2eb', '#cc65fe', '#ffce56', '#4bc0c0', '#ffa1b5']
+        };
+    }
+
+    // Aplica los colores de grid/ticks a las escalas cartesianas (x/y) de un gráfico.
+    // Se usa tanto al crear el gráfico (colores embebidos en las opciones iniciales)
+    // como al refrescar el tema en caliente sobre un gráfico ya existente.
+    function applyCartesianColors(chart, colors) {
+        var scales = chart.options.scales;
+
+        if (!scales) {
+            return;
+        }
+
+        Object.keys(scales).forEach(function (axis) {
+            var scale = scales[axis];
+
+            if (!scale) {
+                return;
+            }
+
+            // Object.assign crea un objeto grid/ticks nuevo en vez de mutar en el
+            // sitio (scale.grid.color = ...). Chart.js reconstruye internamente los
+            // objetos de opciones de un gráfico 'line' ya creado, y mutar una
+            // propiedad suelta sobre esa estructura reactiva provoca
+            // "TypeError: t.startsWith is not a function" al redibujar. Reemplazar
+            // el objeto entero evita tocar esas referencias internas.
+            if (typeof colors.gridColor === 'string' && colors.gridColor) {
+                scale.grid = Object.assign({}, scale.grid, { color: colors.gridColor });
+            }
+
+            if (typeof colors.tickColor === 'string' && colors.tickColor) {
+                scale.ticks = Object.assign({}, scale.ticks, { color: colors.tickColor });
+            }
+        });
+    }
+
+    // Los colores de tema se fijan en las opciones al CREAR cada gráfico (evita el
+    // bug de mutar un gráfico 'line' recién construido). Para que el gráfico
+    // reaccione a un cambio de tema posterior sin recrearlo, cada plantilla registra
+    // aquí su instancia junto con un callback que sabe cómo reaplicar sus colores.
+    var registeredCharts = [];
+
+    function registerThemedChart(chart, applyColors) {
+        registeredCharts.push({ chart: chart, applyColors: applyColors });
+    }
+
+    function refreshThemedCharts() {
+        var colors = getChartColors();
+
+        registeredCharts.forEach(function (entry) {
+            entry.applyColors(entry.chart, colors);
+            // 'none' desactiva la animación de la actualización: solo repinta con
+            // los nuevos colores, sin la transición de entrada de datos.
+            entry.chart.update('none');
+        });
+    }
+
+    // Observa el atributo data-theme del <html> (lo cambia el toggle de tema) para
+    // refrescar todos los gráficos registrados en cuanto el usuario cambia de tema,
+    // sin necesidad de recargar la página.
+    new MutationObserver(function (mutations) {
+        var themeChanged = mutations.some(function (m) { return m.attributeName === 'data-theme'; });
+
+        if (themeChanged) {
+            refreshThemedCharts();
+        }
+    }).observe(document.documentElement, { attributes: true, attributeFilter: ['data-theme'] });
+
+    window.getChartColors = getChartColors;
+    window.applyCartesianColors = applyCartesianColors;
+    window.registerThemedChart = registerThemedChart;
+})();

expenses_manager/expenses/static/expenses/js/nav.js

@@ -0,0 +1,30 @@
+document.addEventListener('DOMContentLoaded', function () {
+    var toggle = document.getElementById('navToggle');
+    var nav = document.getElementById('mainNav');
+
+    if (!toggle || !nav) {
+        return;
+    }
+
+    toggle.addEventListener('click', function () {
+        var isOpen = nav.classList.toggle('nav--open');
+        toggle.setAttribute('aria-expanded', isOpen ? 'true' : 'false');
+    });
+
+    var dropdownToggle = document.getElementById('dropdownToggle');
+    var dropdown = document.getElementById('settingsDropdown');
+
+    if (dropdownToggle && dropdown) {
+        dropdownToggle.addEventListener('click', function () {
+            var isOpen = dropdown.classList.toggle('dropdown--open');
+            dropdownToggle.setAttribute('aria-expanded', isOpen ? 'true' : 'false');
+        });
+
+        document.addEventListener('click', function (event) {
+            if (!dropdown.contains(event.target)) {
+                dropdown.classList.remove('dropdown--open');
+                dropdownToggle.setAttribute('aria-expanded', 'false');
+            }
+        });
+    }
+});

expenses_manager/expenses/static/expenses/js/theme.js

@@ -0,0 +1,20 @@
+document.addEventListener('DOMContentLoaded', function () {
+    var toggle = document.getElementById('themeToggle');
+
+    if (!toggle) {
+        return;
+    }
+
+    function applyIcon(theme) {
+        toggle.textContent = theme === 'dark' ? '☀️' : '🌙';
+    }
+
+    applyIcon(document.documentElement.getAttribute('data-theme'));
+
+    toggle.addEventListener('click', function () {
+        var next = document.documentElement.getAttribute('data-theme') === 'dark' ? 'light' : 'dark';
+        document.documentElement.setAttribute('data-theme', next);
+        localStorage.setItem('theme', next);
+        applyIcon(next);
+    });
+});

expenses_manager/expenses/templates/categories/confirm_delete.html

@@ -1,14 +1,12 @@
-{% extends "expenses/base.html" %}
+{% extends "expenses/_confirm_delete.html" %}
 
-{% block title %}
+{% block title %}Categorías{% endblock %}
-    Categorías
-{% endblock %}
 
-{% block content %}
+{% block delete_heading %}Eliminar categoría{% endblock %}
-    <h2>Eliminar categoría</h2>
 
-    <p>¿Seguro que quieres eliminar la categoría <strong>{{ category.name }}</strong>?</p>
+{% block delete_question %}¿Seguro que quieres eliminar la categoría <strong>{{ category.name }}</strong>?{% endblock %}
 
+{% block delete_warnings %}
     {% if expense_count %}
         <p class="form-errors">
             Esta categoría tiene {{ expense_count }} gasto{{ expense_count|pluralize }} asociado{{ expense_count|pluralize }}
@@ -28,11 +26,6 @@
             </p>
         {% endif %}
     {% endif %}
-
-    <form method="post">
-        {% csrf_token %}
-        {{ form.as_p }}
-        <button class="btn danger">Eliminar</button>
-        <a class="btn" href="{% url 'category_list' %}">Cancelar</a>
-    </form>
 {% endblock %}
+
+{% block cancel_url %}{% url 'category_list' %}{% endblock %}

expenses_manager/expenses/templates/categories/form.html

@@ -10,7 +10,9 @@
     <form method="post">
         {% csrf_token %}
         {{ form.as_p }}
-        <button type="submit">Guardar</button>
+        <div class="form-actions">
-        <a class="btn" href="{% url 'category_list' %}">Cancelar</a>
+            <button type="submit" class="btn btn-primary">Guardar</button>
+            <a class="btn btn-secondary" href="{% url 'category_list' %}">Cancelar</a>
+        </div>
     </form>
 {% endblock %}

expenses_manager/expenses/templates/categories/list.html

@@ -12,12 +12,13 @@
     <form method="post">
         {% csrf_token %}
         {{ form.as_p }}
-        <button type="submit">Crear</button>   
+        <button type="submit" class="btn btn-primary">Crear</button>   
     </form>
 
     <hr>
 
     <h3>Listado</h3>
+    <div class="table-wrap">
     <table>
         <thead>
             <tr>
@@ -38,5 +39,6 @@
             {% endfor %}
         </tbody>
     </table>
+    </div>
 
 {% endblock %}

expenses_manager/expenses/templates/expenses/_confirm_delete.html

@@ -0,0 +1,20 @@
+{% extends "expenses/base.html" %}
+
+{% block title %}Eliminar{% endblock %}
+
+{% block content %}
+    <h1>{% block delete_heading %}Eliminar{% endblock %}</h1>
+
+    <p>{% block delete_question %}¿Seguro que quieres eliminar este elemento?{% endblock %}</p>
+
+    {% block delete_warnings %}{% endblock %}
+
+    <form method="post">
+        {% csrf_token %}
+        {% block delete_extra_fields %}{% endblock %}
+        <div class="form-actions">
+            <button class="btn btn-danger">{% block delete_button %}Eliminar{% endblock %}</button>
+            <a class="btn btn-secondary" href="{% block cancel_url %}{% endblock %}">Cancelar</a>
+        </div>
+    </form>
+{% endblock %}

expenses_manager/expenses/templates/expenses/account_confirm_delete.html

@@ -1,18 +1,11 @@
-{% extends "expenses/base.html" %}
+{% extends "expenses/_confirm_delete.html" %}
+
 {% block title %}Eliminar{% endblock %}
-{% block content %}
 
-    <h1>Eliminar cuenta</h1>
+{% block delete_heading %}Eliminar cuenta{% endblock %}
 
-    <p>
+{% block delete_question %}¿Seguro que quieres eliminar la cuenta <strong>{{ account.name }}</strong>?{% endblock %}
-        ¿Seguro que quieres eliminar la cuenta
-        <strong>{{ account.name }}</strong>
-    </p>
 
-    <form method="post">
+{% block delete_button %}Sí, eliminar{% endblock %}
-        {% csrf_token %}
-        <button class="btn">Sí, eliminar</button>
-        <a class="btn secondary" href="{% url 'account_list' %}">Cancelar</a>
-    </form>
 
-{% endblock %}
+{% block cancel_url %}{% url 'account_list' %}{% endblock %}

expenses_manager/expenses/templates/expenses/account_form.html

@@ -14,8 +14,10 @@
         {% csrf_token %}
         {{ form.as_p }}
 
-        <button type="submit">Guardar</button>
+        <div class="form-actions">
-        <a class="btn secondary" href="{% url 'account_list' %}">Cancelar</a>
+            <button type="submit" class="btn btn-primary">Guardar</button>
+            <a class="btn btn-secondary" href="{% url 'account_list' %}">Cancelar</a>
+        </div>
     </form>
 
 {% endblock %}

expenses_manager/expenses/templates/expenses/account_list.html

@@ -6,6 +6,7 @@
 
     <a class="btn" href="{% url 'account_create' %}">➕ Nueva cuenta</a>
 
+    <div class="table-wrap">
     <table>
         <thead>
             <tr>
@@ -46,4 +47,5 @@
             {% endfor %}
         </tbody>
     </table>
+    </div>
 {% endblock %}

expenses_manager/expenses/templates/expenses/base.html

@@ -1,18 +1,34 @@
 {% load static %}
-<!DOCTYPE>
+<!DOCTYPE html>
-<html>
+<html lang="es">
     <head>
         <meta charset="utf-8">
+        <meta name="viewport" content="width=device-width, initial-scale=1.0">
         <title>{% block title %}Expenses manager{% endblock %}</title>
+        <script>
+            (function() {
+                var theme = localStorage.getItem('theme');
+                if (!theme) {
+                    theme = window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
+                }
+                document.documentElement.setAttribute('data-theme', theme);
+            })();
+        </script>
         <link rel="stylesheet" href="{% static 'expenses/css/base.css' %}">
         <script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
+        <script src="{% static 'expenses/js/charts.js' %}"></script>
         {% block extra_css %}{% endblock %}
     </head>
 
     <body>
         {% if user.is_authenticated %}
             <header class="topbar">
-                <nav class="nav">
+                <button type="button" class="nav-toggle" id="navToggle" aria-label="Abrir menú" aria-expanded="false" aria-controls="mainNav">
+                    <span class="nav-toggle-bar"></span>
+                    <span class="nav-toggle-bar"></span>
+                    <span class="nav-toggle-bar"></span>
+                </button>
+                <nav class="nav" id="mainNav">
                     <a href="{% url 'home' %}" class="nav-item {% if active_menu == 'home' %}active{% endif %} ">Home</a>
                     <a href="{% url 'dashboard' %}" class="nav-item {% if active_menu == 'dashboard' %}active{% endif %} ">Dashboard</a>
                     <a href="{% url 'expense_list' %}" class="nav-item {% if active_menu == 'expenses' %}active{% endif %} ">Gastos</a>
@@ -21,10 +37,10 @@
                     <!-- <a href="{% url 'tag_list' %}" class="nav-item {% if active_menu == 'tags' %}active{% endif %} ">Etiquetas</a> -->
                     <a href="{% url 'fuel_list' %}" class="nav-item {% if active_menu == 'fuel' %}active{% endif %} ">Repostajes</a>
                     <!-- <a href="{% url 'category_list' %}" class="nav-item {% if active_menu == 'categories' %}active{% endif %} ">Categorías</a> -->
-                    <div class="nav-item dropdown {% if active_menu == 'settings' %}active{% endif %}">
+                    <div class="nav-item dropdown {% if active_menu == 'settings' %}active{% endif %}" id="settingsDropdown">
-                        <span class="dropdown-toggle">Configuraciones ▼</span>
+                        <button type="button" class="dropdown-toggle" id="dropdownToggle" aria-haspopup="true" aria-expanded="false" aria-controls="dropdownMenu">Configuraciones ▼</button>
 
-                        <div class="dropdown-menu">
+                        <div class="dropdown-menu" id="dropdownMenu">
                             <a href="{% url 'category_list' %}">Categorías</a>
                             <a href="{% url 'tag_list' %}">Etiquetas</a>
                             <a href="{% url 'goal_list' %}">Objetivos</a>
@@ -33,6 +49,8 @@
 
                     <span class="spacer"></span>
 
+                    <button type="button" class="theme-toggle" id="themeToggle" aria-label="Cambiar tema" title="Cambiar tema"></button>
+
                     <a href="{% url 'password_change' %}">{{ request.user.username }}</a>
 
                     <form method="post" action="{% url 'logout' %}" class="logout-form">
@@ -58,5 +76,7 @@
         </main>
 
         {% block extra_js %}{% endblock %}
+        <script src="{% static 'expenses/js/nav.js' %}" defer></script>
+        <script src="{% static 'expenses/js/theme.js' %}" defer></script>
     </body>
 </html>

expenses_manager/expenses/templates/expenses/base_auth.html

@@ -1,9 +1,19 @@
 {% load static %}
 <!DOCTYPE html>
-<html>
+<html lang="es">
     <head>
         <meta charset="utf-8">
+        <meta name="viewport" content="width=device-width, initial-scale=1.0">
         <title>{% block title %}Login{% endblock %}</title>
+        <script>
+            (function() {
+                var theme = localStorage.getItem('theme');
+                if (!theme) {
+                    theme = window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
+                }
+                document.documentElement.setAttribute('data-theme', theme);
+            })();
+        </script>
         <link rel="stylesheet" href="{% static 'expenses/css/base.css' %}">
     </head>
     <body>

expenses_manager/expenses/templates/expenses/dashboard.html

@@ -41,11 +41,14 @@
             <a href="{% url 'dashboard' %}?period=this_year" class="preset {% if period == 'this_year' %}active{% endif %}">
                 Este año
             </a>
-            {% if period %}
-                <a href="{% url 'dashboard' %}" style="color: red; margin-left: 10px;">❌ Quitar filtros temporales</a>
-            {% endif %}
         </div>
 
+        {% if period %}
+            <div class="clear-filters-row">
+                <a href="{% url 'dashboard' %}" class="clear-filters">❌ Quitar filtros temporales</a>
+            </div>
+        {% endif %}
+
         <br>
 
         <form method="get" action="{% url 'dashboard' %}" id="filtered_form">
@@ -86,7 +89,7 @@
                 Comparar periodo anterior
             </label>
 
-            <button type="submit">Aplicar Filtros</button>
+            <button type="submit" class="btn btn-primary">Aplicar Filtros</button>
         </form>
     </section>
     <script>
@@ -149,10 +152,10 @@
         </div>
         
         {% if selected_month == today.month and selected_year == today.year %}
-            <div class="kpi-card" style="border-left: 4px solid #ff9f43;">
+            <div class="kpi-card" style="border-left: 4px solid var(--color-warning-accent);">
                 <span class="kpi-label">Proyección fin de mes</span>
                 <span class="kpi-value">{{ projected_end_of_month|floatformat:2 }}€</span>
-                <small style="color: gray; display:block;">Basado en tu ritmo de gasto actual</small>
+                <small style="color: var(--color-text-muted); display:block;">Basado en tu ritmo de gasto actual</small>
             </div>
         {% endif %}
     </section>
@@ -164,15 +167,16 @@
                 Gastos periodo actual: <strong>{{ kpi_total|floatformat:2 }} €</strong><br>
                 Gastos periodo anterior: <strong>{{ kpi_previous_total|floatformat:2 }} €</strong><br>
                 Diferencia:
-                <strong style="color: {% if kpi_trend == 'up' %}#d9534f{% else %}#5cb85c{% endif %};">
+                <strong style="color: {% if kpi_trend == 'up' %}var(--color-danger-accent){% else %}var(--color-success-accent){% endif %};">
                     {% if kpi_trend == "up" %}+{% endif %}{{ kpi_difference|floatformat:2 }}€ ({{ kpi_percentage|floatformat:1 }}%)
                 </strong>
-                <small style="display:block; color:gray;">
+                <small style="display:block; color: var(--color-text-muted);">
                     {% if kpi_trend == "up" %}⚠️ Has gastado más que el periodo pasado. {% else %} ¡Bien! Has reducido tus gastos. {% endif %}
                 </small>
             </p>
 
             <h3>Desglose de cambios por categoría</h3>
+            <div class="table-wrap">
             <table>
                 <thead>
                     <tr>
@@ -188,13 +192,14 @@
                             <td>{{ cat.category }}</td>
                             <td>{{ cat.previous|floatformat:2 }}€</td>
                             <td>{{ cat.current|floatformat:2 }}€</td>
-                            <td style="font-weight: bold; color: {% if cat.difference > 0 %}#d9534f{% else %}#5cb85c{% endif %};">
+                            <td style="font-weight: bold; color: {% if cat.difference > 0 %}var(--color-danger-accent){% else %}var(--color-success-accent){% endif %};">
                                 {% if cat.difference > 0 %}+{% endif %}{{ cat.difference|floatformat:2 }}€
                             </td>
                         </tr>
                     {% endfor %}
                 </tbody>
             </table>
+            </div>
         </section>
     {% endif %}
 
@@ -203,22 +208,23 @@
     <!-- ========================= -->
     
     <div class="charts-container">
-        <section class="chart-box" style="width: 45%; min-width: 300px; max-width: 550px;">
+        <section>
             <h3>Evolución de Gastos ({% if chart_type == 'day' %}Por día {% else %} Por Meses{% endif %})</h3>
-            <div style="position: relative; width: 100%; height: 350px; padding-bottom: 20px;">
+            <div class="chart-box">
                 <canvas id="mainChart"></canvas>
             </div>
         </section>
 
-        <section class="chart-box" style="width: 30%; min-width: 280px; max-width: 400px;">
+        <section>
             <h3>Distribución por Categorías</h3>
-            <div style="position: relative; width: 100%; height: 350px; display: flex; align-items: center; justify-content: center">
+            <div class="chart-box">
                 <canvas id="categoryChart"></canvas>
             </div>
         </section>
 
         <section>
             <h3>Gastos Recientes</h3>
+            <div class="table-wrap">
             <table class="table">
                 <thead>
                     <tr>
@@ -236,13 +242,14 @@
                             <td>{{ exp.account.name }}</td>
                             <td>{{ exp.category.name }}</td>
                             <td>{{ exp.description|default:"-" }}</td>
-                            <td style="color: #d9534f; font-weight: bold;">{{ exp.amount|floatformat:2 }}</td>
+                            <td style="color: var(--color-danger-accent); font-weight: bold;">{{ exp.amount|floatformat:2 }}</td>
                         </tr>
                     {% empty %}
                         <tr><td colspan="7">No hay gastos recientes registrados</td></tr>
                     {% endfor %}
                 </tbody>
             </table>
+            </div>
         </section>
     </div>
     
@@ -252,24 +259,31 @@
         const catLabels = [{% for row in by_category_chart %}"{{ row.category__name }}",{% endfor %}];
         const catData = [{% for row in by_category_chart %}{{ row.total|unlocalize }},{% endfor %}];
 
-        new Chart(document.getElementById('categoryChart'), {
+        const categoryChartColors = getChartColors();
+
+        const categoryChart = new Chart(document.getElementById('categoryChart'), {
             type: 'pie',
             data: {
                 labels: catLabels,
                 datasets: [{
                     data: catData,
-                    backgroundColor: [
+                    backgroundColor: categoryChartColors.palette
-                        '#ff6384', '#36a2eb', '#cc65fe', '#ffce56', '#4bc0c0', '#ffa1b5'
-                    ]
                 }]
             },
             options: {
                 responsive: true,
                 maintainAspectRatio: false,
                 plugins: {
-                    legend: { position: 'right' }
+                    legend: {
+                        position: 'right',
+                        labels: { color: categoryChartColors.tickColor }
                     }
                 }
+            }
+        });
+
+        registerThemedChart(categoryChart, function (chart, colors) {
+            chart.options.plugins.legend.labels.color = colors.tickColor;
         });
     </script>
 
@@ -290,24 +304,39 @@
         const labels = {{ chart_labels|safe }};
         const data = {{ chart_data|safe }};
         const ctx = document.getElementById('mainChart');
+        const mainChartColors = getChartColors();
 
-        new Chart(ctx, {
+        const mainChart = new Chart(ctx, {
             type: 'bar',
             data: {
                 labels: labels,
                 datasets:[{
                     label: 'Gastos (€)',
                     data: data,
-                    backgroundColor: 'rgba(54, 162, 235, 0.6)',
+                    backgroundColor: mainChartColors.primaryColor,
-                    backgroundColor: 'rgba(54, 162, 235, 1)',
                     borderWidth: 1
                 }]
             },
             options: {
                 responsive: true,
                 maintainAspectRatio: false,
-                scales: { y: { beginAtZero: true } }
+                scales: {
+                    x: {
+                        grid: { color: mainChartColors.gridColor },
+                        ticks: { color: mainChartColors.tickColor }
+                    },
+                    y: {
+                        beginAtZero: true,
+                        grid: { color: mainChartColors.gridColor },
+                        ticks: { color: mainChartColors.tickColor }
                     }
+                }
+            }
+        });
+
+        registerThemedChart(mainChart, function (chart, colors) {
+            chart.data.datasets[0].backgroundColor = colors.primaryColor;
+            applyCartesianColors(chart, colors);
         });
 
         const allMonths = ["Ene", "Feb", "Mar", "Abr", "May", "Jun", "Jul", "Ago", "Sep", "Oct", "Nov", "Dic"];
@@ -316,8 +345,9 @@
             (function() {
                 const dataAccount = {{ acc.data|safe }};
                 const filteredLabels = allMonths.slice(0, dataAccount.length);
+                const accountChartColors = getChartColors();
 
-                new Chart(
+                const accountChart = new Chart(
                     document.getElementById('accountChart{{ acc.id }}'),
                     {
                         type: 'line',
@@ -327,8 +357,8 @@
                                 label: 'Saldo Real (€)',
                                 data: dataAccount,
                                 fill: false,
-                                borderColor: 'rgba(54, 162, 235, 1)',
+                                borderColor: accountChartColors.primaryColor,
-                                backgroundColor: 'rgba(54, 162, 235, 0.2)',
+                                backgroundColor: accountChartColors.primaryFill,
                                 tension: 0.1
                             }]
                         },
@@ -336,13 +366,25 @@
                             responsive: true,
                             maintainAspectRatio: false,
                             scales: {
+                                x: {
+                                    grid: { color: accountChartColors.gridColor },
+                                    ticks: { color: accountChartColors.tickColor }
+                                },
                                 y: {
-                                    beginAtZero: false
+                                    beginAtZero: false,
+                                    grid: { color: accountChartColors.gridColor },
+                                    ticks: { color: accountChartColors.tickColor }
                                 }
                             }
                         }
                     }
                 );
+
+                registerThemedChart(accountChart, function (chart, colors) {
+                    chart.data.datasets[0].borderColor = colors.primaryColor;
+                    chart.data.datasets[0].backgroundColor = colors.primaryFill;
+                    applyCartesianColors(chart, colors);
+                });
             })();
         {% endfor %}
     </script>
@@ -398,6 +440,7 @@
     <!-- ========================= -->
     <!-- Categories -->
     <!-- ========================= -->
+    <div class="table-wrap">
     <table>
         <thead>
             <tr>
@@ -414,5 +457,6 @@
             {% endfor %}
         </tbody>
     </table>
+    </div>
 
 {% endblock %}

expenses_manager/expenses/templates/expenses/expense_confirm_delete.html

@@ -1,21 +1,16 @@
-{% extends "expenses/base.html" %}
+{% extends "expenses/_confirm_delete.html" %}
 
 {% block title %}Eliminar gasto{% endblock %}
 
-{% block content %}
+{% block delete_heading %}Eliminar gasto{% endblock %}
-    <h1>Eliminar gasto</h1>
 
-    <p>
+{% block delete_question %}
     ¿Seguro que quieres eliminar el gasto de
     <strong>{{ expense.amount }}€</strong>
     del {{ expense.date }} perteneciente a
     <strong>{{ expense.account }}</strong>?
-    </p>
-
-    <form method="post">
-        {% csrf_token %}
-        <button class="btn">Sí, eliminar</button>
-        <a class="btn secondary" href="{% url 'expense_list' %}">Cancelar</a>
-    </form>
-
 {% endblock %}
+
+{% block delete_button %}Sí, eliminar{% endblock %}
+
+{% block cancel_url %}{% url 'expense_list' %}{% endblock %}

expenses_manager/expenses/templates/expenses/expense_form.html

@@ -46,14 +46,15 @@
             {% endif %}
         {% endfor %}
 
-        <button type="submit">
+        <div class="form-actions">
+            <button type="submit" class="btn btn-primary">
                 {% if form.instance.pk %}
                     Guardar gasto
                 {% else %}
                     Crear gasto
                 {% endif %}
             </button>
+            <a class="btn btn-secondary" href="{% url 'expense_list' %}">Volver</a>
+        </div>
     </form>
-
-    <a href="{% url 'expense_list' %}">Volver</a>
 {% endblock %}

expenses_manager/expenses/templates/expenses/expense_list.html

@@ -44,8 +44,8 @@
                 {% endfor %}
             </select>
 
-            <button type="submit">Filtrar</button>
+            <button type="submit" class="btn btn-primary">Filtrar</button>
-            <a href="{% url 'expense_list' %}" class="btn-secondary">Limpiar</a>
+            <a href="{% url 'expense_list' %}" class="btn btn-secondary">Limpiar</a>
         </div>
 
         <br>
@@ -100,6 +100,7 @@
         <strong>Categorías:</strong> {{ kpi_categories }}
     </section>
 
+    <div class="table-wrap">
     <table>
         <thead>
             <tr>
@@ -147,6 +148,7 @@
             {% endfor %}
         </tbody>
     </table>
+    </div>
 
     <div class="pagination">
         <span class="step-links">            

expenses_manager/expenses/templates/expenses/home.html

@@ -34,29 +34,49 @@
         <div class="dashboard-grid">
             <div class="card card-chart">
                 <h2>Últimos meses</h2>
+                <div class="canvas-wrapper">
                     <canvas id="miniChart"></canvas>
                 </div>
             </div>
+        </div>
 
         <script>
             const labels = {{ mini_chart_labels|safe }};
             const data = {{ mini_chart_data|safe }};
             
             const ctx = document.getElementById('miniChart');
+            const miniChartColors = getChartColors();
 
-            new Chart(ctx, {
+            const miniChart = new Chart(ctx, {
                 type: 'bar',
                 data: {
                     labels: labels,
                     datasets:[{
                         label: 'Gastos',
                         data: data,
+                        backgroundColor: miniChartColors.primaryColor,
                     }]
                 },
                 options: {
                     responsive: true,
-                    maintainAspectRatio: false
+                    maintainAspectRatio: false,
+                    scales: {
+                        x: {
+                            grid: { color: miniChartColors.gridColor },
+                            ticks: { color: miniChartColors.tickColor }
+                        },
+                        y: {
+                            beginAtZero: true,
+                            grid: { color: miniChartColors.gridColor },
+                            ticks: { color: miniChartColors.tickColor }
                         }
+                    }
+                }
+            });
+
+            registerThemedChart(miniChart, function (chart, colors) {
+                chart.data.datasets[0].backgroundColor = colors.primaryColor;
+                applyCartesianColors(chart, colors);
             });
         </script>
 

expenses_manager/expenses/templates/expenses/income_confirm_delete.html

@@ -1,20 +1,16 @@
-{% extends "expenses/base.html" %}
+{% extends "expenses/_confirm_delete.html" %}
+
 {% block title %}Eliminar ingreso{% endblock %}
 
-{% block content %}        
+{% block delete_heading %}Eliminar ingreso{% endblock %}
-    <h1>Eliminar ingreso</h1>
 
-    <p>
+{% block delete_question %}
     ¿Seguro que quieres eliminar el ingreso de
     <strong>{{ income.amount }}€</strong>
     del {{ income.date }} perteneciente a
     <strong>{{ income.account }}</strong>?
-    </p>
-
-    <form method="post">
-        {% csrf_token %}
-        <button class="btn">Sí, eliminar</button>
-        <a class="btn secondary" href="{% url 'income_list' %}">Cancelar</a>
-    </form>
-
 {% endblock %}
+
+{% block delete_button %}Sí, eliminar{% endblock %}
+
+{% block cancel_url %}{% url 'income_list' %}{% endblock %}

expenses_manager/expenses/templates/expenses/income_form.html

@@ -19,14 +19,15 @@
     <form method="post">
         {% csrf_token %}
         {{ form.as_p }}
-        <button type="submit">
+        <div class="form-actions">
+            <button type="submit" class="btn btn-primary">
                 {% if form.instance.pk %}
                     Guardar ingreso
                 {% else %}
                     Crear ingreso
                 {% endif %}
             </button>
+            <a class="btn btn-secondary" href="{% url 'income_list' %}">Volver</a>
+        </div>
     </form>
-
-    <a class="btn secondary" href="{% url 'income_list' %}">Volver</a>
 {% endblock %}

expenses_manager/expenses/templates/expenses/income_list.html

@@ -5,6 +5,7 @@
 
     <a class="btn" href="{% url 'income_create' %}">➕ Nuevo ingreso</a>
 
+    <div class="table-wrap">
     <table>
         <thead>
             <tr>
@@ -37,5 +38,6 @@
             {% endfor %}
         </tbody>
     </table>
+    </div>
 
 {% endblock %}

expenses_manager/expenses/templates/expenses/tag_confirm_delete.html

@@ -1,17 +1,9 @@
-{% extends "expenses/base.html" %}
+{% extends "expenses/_confirm_delete.html" %}
+
 {% block title %}Etiquetas{% endblock %}
-{% block content %}
-    <h1>Eliminar etiqueta</h1>
 
-    <p>
+{% block delete_heading %}Eliminar etiqueta{% endblock %}
-        ¿Seguro que quieres eliminar la etiqueta
-        <strong>{{ tag.name }}€</strong>?
-    </p>
 
-    <form method="post">
+{% block delete_question %}¿Seguro que quieres eliminar la etiqueta <strong>{{ tag.name }}</strong>?{% endblock %}
-        {% csrf_token %}
-        <button class="btn">Eliminar</button>
-        <a class="btn secondary" href="{% url 'tag_list' %}">Cancelar</a>
-    </form>
 
-{% endblock %}
+{% block cancel_url %}{% url 'tag_list' %}{% endblock %}

expenses_manager/expenses/templates/expenses/tag_form.html

@@ -6,8 +6,9 @@
     <form method="post">
         {% csrf_token %}
         {{ form.as_p }}
-        <button type="submit">Guardar</button>
+        <div class="form-actions">
+            <button type="submit" class="btn btn-primary">Guardar</button>
+            <a class="btn btn-secondary" href="{% url 'tag_list' %}">Volver</a>
+        </div>
     </form>
-
-    <a class="btn secondary" href="{% url 'tag_list' %}">Volver</a>
 {% endblock %}

expenses_manager/expenses/templates/fuel/confirm_delete.html

@@ -1,26 +1,23 @@
-{% extends "expenses/base.html" %}
+{% extends "expenses/_confirm_delete.html" %}
 
-{% block title %}
+{% block title %}Repostajes{% endblock %}
-    Repostajes
-{% endblock %}
 
-{% block content %}
+{% block delete_heading %}Eliminar repostaje.{% endblock %}
-    <h2>Eliminar repostaje.</h2>
 
-    <p>
+{% block delete_question %}
     ¿Seguro que quieres eliminar el repostaje del
     <strong>{{ fuel.expense.date }}</strong>
     ({{ fuel.liters }}L por {{ fuel.expense.amount }}€)?
-    </p>
+{% endblock %}
 
+{% block delete_warnings %}
     <p class="form-errors">
         Se eliminará también el gasto asociado en el listado de gastos.
     </p>
-
-    <form method="post">
-        {% csrf_token %}
-        {% if next %}<input type="hidden" name="next" value="{{ next }}">{% endif %}
-        <button class="btn danger">Eliminar</button>
-        <a class="btn" href="{% url 'fuel_list' %}">Cancelar</a>
-    </form>
 {% endblock %}
+
+{% block delete_extra_fields %}
+    {% if next %}<input type="hidden" name="next" value="{{ next }}">{% endif %}
+{% endblock %}
+
+{% block cancel_url %}{% if next %}{{ next }}{% else %}{% url 'fuel_list' %}{% endif %}{% endblock %}

expenses_manager/expenses/templates/fuel/create.html

@@ -21,20 +21,22 @@
         {% csrf_token %}
         {% if next %}<input type="hidden" name="next" value="{{ next }}">{% endif %}
         {{ form.as_p }}
-        <button type="submit">
+        <div class="form-actions">
+            <button type="submit" class="btn btn-primary">
                 {% if editing %}
                     Guardar repostaje
                 {% else %}
                     Crear repostaje
                 {% endif %}
             </button>
-    </form>
 
             {% if next %}
-        <a class="btn" href="{{ next }}">Volver</a>
+                <a class="btn btn-secondary" href="{{ next }}">Volver</a>
             {% elif editing %}
-        <a class="btn" href="{% url 'expense_list' %}">Volver</a>
+                <a class="btn btn-secondary" href="{% url 'expense_list' %}">Volver</a>
             {% else %}
-        <a class="btn" href="{% url 'fuel_list' %}">Volver</a>
+                <a class="btn btn-secondary" href="{% url 'fuel_list' %}">Volver</a>
             {% endif %}
+        </div>
+    </form>
 {% endblock %}

expenses_manager/expenses/templates/fuel/list.html

@@ -12,6 +12,7 @@
 
     </div>
 
+    <div class="table-wrap">
     <table>
         <thead>
             <tr>
@@ -41,6 +42,7 @@
             {% endfor %}
         </tbody>
     </table>
+    </div>
 
     <form method="get">
         <select name="year" onchange="this.form.submit()">
@@ -57,30 +59,72 @@
     
     <script>
         const monthlyData = {{ monthly_data|safe }};
+        const monthlyChartColors = getChartColors();
 
-        new Chart(document.getElementById('monthlyChart'), {
+        const monthlyChart = new Chart(document.getElementById('monthlyChart'), {
             type: 'bar',
             data: {
                 labels: ['Ene','Feb','Mar','Abr','May','Jun','Jul','Ago','Sep','Oct','Nov','Dic'],
                 datasets: [{
                     label: 'Gasto mensual',
-                    data: monthlyData
+                    data: monthlyData,
+                    backgroundColor: monthlyChartColors.primaryColor
                 }]
+            },
+            options: {
+                scales: {
+                    x: {
+                        grid: { color: monthlyChartColors.gridColor },
+                        ticks: { color: monthlyChartColors.tickColor }
+                    },
+                    y: {
+                        beginAtZero: true,
+                        grid: { color: monthlyChartColors.gridColor },
+                        ticks: { color: monthlyChartColors.tickColor }
                     }
+                }
+            }
+        });
+
+        registerThemedChart(monthlyChart, function (chart, colors) {
+            chart.data.datasets[0].backgroundColor = colors.primaryColor;
+            applyCartesianColors(chart, colors);
         });
 
         const kmData = {{ km_data|safe }};
         const kmDates = {{ km_dates|safe }};
+        const kmChartColors = getChartColors();
 
-        new Chart(document.getElementById('kmChart'), {
+        const kmChart = new Chart(document.getElementById('kmChart'), {
             type: 'line',
             data: {
                 labels: kmDates,
                 datasets: [{
                     label: 'Km entre repostajes',
-                    data: kmData
+                    data: kmData,
+                    borderColor: kmChartColors.primaryColor,
+                    backgroundColor: kmChartColors.primaryFill
                 }]
+            },
+            options: {
+                scales: {
+                    x: {
+                        grid: { color: kmChartColors.gridColor },
+                        ticks: { color: kmChartColors.tickColor }
+                    },
+                    y: {
+                        beginAtZero: true,
+                        grid: { color: kmChartColors.gridColor },
+                        ticks: { color: kmChartColors.tickColor }
                     }
+                }
+            }
+        });
+
+        registerThemedChart(kmChart, function (chart, colors) {
+            chart.data.datasets[0].borderColor = colors.primaryColor;
+            chart.data.datasets[0].backgroundColor = colors.primaryFill;
+            applyCartesianColors(chart, colors);
         });
     </script>
 

expenses_manager/expenses/templates/goals/confirm_delete.html

@@ -1,18 +1,9 @@
-{% extends "expenses/base.html" %}
+{% extends "expenses/_confirm_delete.html" %}
+
 {% block title %}Objetivos{% endblock %}
-{% block content %}
 
-<h1>Eliminar objetivo</h1>
+{% block delete_heading %}Eliminar objetivo{% endblock %}
 
-<p>
+{% block delete_question %}¿Seguro que quieres eliminar el objetivo <strong>{{ goal.name }}</strong>?{% endblock %}
-    ¿Seguro que quieres eliminar el objetivo
-    <strong>{{ goal.name }}</strong>?
-</p>
 
-<form method="post">
+{% block cancel_url %}{% url 'goal_list' %}{% endblock %}
-    {% csrf_token %}
-    <button class="btn">Eliminar</button>
-    <a class="btn secondary" href="{% url 'goal_list' %}">Cancelar</a>
-</form>
-
-{% endblock %}

expenses_manager/expenses/templates/goals/form.html

@@ -11,10 +11,11 @@
     <form method="post">
         {% csrf_token %}
         {{ form.as_p }}
-        <button type="submit">
+        <div class="form-actions">
+            <button type="submit" class="btn btn-primary">
                 Guardar
             </button>
+            <a class="btn btn-secondary" href="{% url 'goal_list' %}">Volver</a>
+        </div>
     </form>
-
-    <a class="btn secondary" href="{% url 'goal_list' %}">Volver</a>
 {% endblock %}

expenses_manager/expenses/templates/goals/list.html

@@ -9,8 +9,9 @@
 {% block content %}
 <h2>Objetivos</h2>
 
-<a class=btn href="{% url 'goal_create' %}">➕ Nuevo objetivo</a>
+<a class="btn btn-primary" href="{% url 'goal_create' %}">➕ Nuevo objetivo</a>
 
+<div class="table-wrap">
 <table>
     <tr>
         <th>Nombre</th>
@@ -53,5 +54,6 @@
     </tr>
     {% endfor %}
 </table>
+</div>
 
 {% endblock %}

expenses_manager/expenses/templates/registration/login.html

@@ -7,7 +7,7 @@
 <form method="post">
     {% csrf_token %}
     {{ form.as_p }}
-    <button type="submit">Entrar</button>
+    <button type="submit" class="btn btn-primary">Entrar</button>
 </form>
 
 <p class="auth-help">

expenses_manager/expenses/templates/registration/password_change_form.html

@@ -5,6 +5,6 @@
     <form method="post">
         {% csrf_token %}
         {{ form.as_p }}
-        <button type="submit">Cambiar</button>
+        <button type="submit" class="btn btn-primary">Cambiar</button>
     </form>
 {% endblock %}

expenses_manager/expenses/tests/test_fuel.py

@@ -67,3 +67,165 @@ def test_fuel_delete_post_cascades_to_fuelentry(auth_client, user, account, cate
 
     assert not Expense.objects.filter(pk=expense.pk).exists()
     assert not FuelEntry.objects.filter(pk=entry.pk).exists()
+
+
+def _edit_payload(account, edit_date, amount, odometer, liters, next_url=None):
+    payload = {
+        "date": edit_date.strftime("%Y-%m-%d"),
+        "amount": str(amount),
+        "account": account.pk,
+        "odometer": str(odometer),
+        "liters": str(liters),
+    }
+    if next_url is not None:
+        payload["next"] = next_url
+    return payload
+
+
+def test_fuel_edit_post_updates_expense_and_fuelentry(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"), amount=Decimal("50"))
+    expense = entry.expense
+    new_date = date(2024, 3, 1)
+
+    response = auth_client.post(
+        reverse('fuel_edit', args=[expense.pk]),
+        _edit_payload(account, new_date, Decimal("45.50"), 1200, Decimal("22.5")),
+    )
+
+    assert response.status_code == 302
+
+    expense.refresh_from_db()
+    entry.refresh_from_db()
+
+    assert expense.amount == Decimal("45.50")
+    assert expense.date == new_date
+    assert expense.account_id == account.pk
+    assert entry.odometer == 1200
+    assert entry.liters == Decimal("22.5")
+
+
+def test_fuel_edit_invalid_post_returns_200_and_does_not_modify(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"), amount=Decimal("50"))
+    expense = entry.expense
+    original_date = expense.date
+
+    payload = _edit_payload(account, date(2024, 3, 1), Decimal("45.50"), 1200, Decimal("22.5"))
+    payload["liters"] = ""
+
+    response = auth_client.post(reverse('fuel_edit', args=[expense.pk]), payload)
+
+    assert response.status_code == 200
+
+    expense.refresh_from_db()
+    entry.refresh_from_db()
+
+    assert expense.amount == Decimal("50")
+    assert expense.date == original_date
+    assert entry.odometer == 1000
+    assert entry.liters == Decimal("20")
+
+
+def test_fuel_edit_redirects_to_next_when_relative(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"))
+    expense = entry.expense
+    next_url = reverse('expense_list')
+
+    response = auth_client.post(
+        reverse('fuel_edit', args=[expense.pk]),
+        _edit_payload(account, date(2024, 3, 1), Decimal("45.50"), 1200, Decimal("22.5"), next_url=next_url),
+    )
+
+    assert response.status_code == 302
+    assert response.url == next_url
+
+
+def test_fuel_edit_ignores_external_next(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"))
+    expense = entry.expense
+
+    response = auth_client.post(
+        reverse('fuel_edit', args=[expense.pk]),
+        _edit_payload(
+            account, date(2024, 3, 1), Decimal("45.50"), 1200, Decimal("22.5"),
+            next_url="https://evil.com",
+        ),
+    )
+
+    assert response.status_code == 302
+    assert response.url == reverse('expense_list')
+
+
+def test_fuel_delete_get_does_not_delete(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"))
+    expense = entry.expense
+
+    response = auth_client.get(reverse('fuel_delete', args=[expense.pk]))
+
+    assert response.status_code == 200
+    assert Expense.objects.filter(pk=expense.pk).exists()
+    assert FuelEntry.objects.filter(pk=entry.pk).exists()
+
+
+def test_fuel_delete_get_cancel_link_uses_next_when_provided(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"))
+    expense = entry.expense
+    next_url = reverse('expense_list')
+
+    response = auth_client.get(reverse('fuel_delete', args=[expense.pk]), {"next": next_url})
+
+    assert response.status_code == 200
+    assert f'<a class="btn btn-secondary" href="{next_url}">Cancelar</a>'.encode() in response.content
+
+
+def test_fuel_delete_get_cancel_link_falls_back_to_fuel_list_without_next(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"))
+    expense = entry.expense
+    fuel_list_url = reverse('fuel_list')
+
+    response = auth_client.get(reverse('fuel_delete', args=[expense.pk]))
+
+    assert response.status_code == 200
+    assert f'<a class="btn btn-secondary" href="{fuel_list_url}">Cancelar</a>'.encode() in response.content
+
+
+def test_fuel_delete_post_redirects_to_next_when_relative(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"))
+    expense = entry.expense
+    next_url = reverse('expense_list')
+
+    response = auth_client.post(reverse('fuel_delete', args=[expense.pk]), {"next": next_url})
+
+    assert response.status_code == 302
+    assert response.url == next_url
+
+
+def test_fuel_delete_post_ignores_external_next(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"))
+    expense = entry.expense
+
+    response = auth_client.post(reverse('fuel_delete', args=[expense.pk]), {"next": "https://evil.com"})
+
+    assert response.status_code == 302
+    assert response.url == reverse('fuel_list')
+
+
+def test_fuel_delete_get_ignores_unsafe_next_in_cancel_link(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"))
+    expense = entry.expense
+    fuel_list_url = reverse('fuel_list')
+
+    response = auth_client.get(reverse('fuel_delete', args=[expense.pk]), {"next": "javascript:alert(1)"})
+
+    assert response.status_code == 200
+    assert b"javascript:" not in response.content
+    assert f'<a class="btn btn-secondary" href="{fuel_list_url}">Cancelar</a>'.encode() in response.content
+
+
+def test_fuel_edit_get_ignores_unsafe_next_in_cancel_link(auth_client, user, account, category):
+    entry = _make_fuel_entry(user, account, category, odometer=1000, liters=Decimal("20"))
+    expense = entry.expense
+
+    response = auth_client.get(reverse('fuel_edit', args=[expense.pk]), {"next": "javascript:alert(1)"})
+
+    assert response.status_code == 200
+    assert b"javascript:" not in response.content

expenses_manager/expenses/views.py

@@ -30,7 +30,7 @@ def _get_int(value):
         return None
 
 
-def _redirect_back(request, fallback):
+def _safe_next(request):
     next_url = request.POST.get("next") or request.GET.get("next")
 
     if next_url and url_has_allowed_host_and_scheme(
@@ -38,9 +38,14 @@ def _redirect_back(request, fallback):
         allowed_hosts={request.get_host()},
         require_https=request.is_secure(),
     ):
-        return redirect(next_url)
+        return next_url
 
-    return redirect(fallback)
+    return ""
+
+
+def _redirect_back(request, fallback):
+    next_url = _safe_next(request)
+    return redirect(next_url or fallback)
 
 
 def sub_months(year, month, n):
@@ -237,7 +242,6 @@ def expense_create(request):
 
 @login_required
 def expense_edit(request, pk):
-    # sourcery skip: assign-if-exp, merge-else-if-into-elif
     expense = get_object_or_404(
         Expense,
         pk=pk,
@@ -805,20 +809,16 @@ def fuel_list(request):
 
 @login_required
 def fuel_edit(request, pk):
-    expense = get_object_or_404(
+    expense = get_object_or_404(Expense, pk=pk, owner=request.user)
-        Expense,
-        pk=pk,
-        owner=request.user,
-    )
 
     fuel = get_object_or_404(FuelEntry, expense=expense)
 
     if request.method == "POST":
-        form = FuelEntryForm(request.POST, user=request.user)
+        form = FuelEntryForm(request.POST, instance=expense, user=request.user)
 
         if form.is_valid():
             # Update expense
-            expense.date = form.save(commit=False)
+            expense = form.save(commit=False)
             expense.description = "Repostaje"
             expense.save()
 
@@ -831,7 +831,7 @@ def fuel_edit(request, pk):
     else:
         form = FuelEntryForm(instance=expense, user=request.user)
 
-    next_url = request.POST.get("next") or request.GET.get("next", "")
+    next_url = _safe_next(request)
 
     return render(
         request,
@@ -855,7 +855,7 @@ def fuel_delete(request, pk):
         messages.success(request, "Repostaje eliminado.")
         return _redirect_back(request, "fuel_list")
 
-    next_url = request.POST.get("next") or request.GET.get("next", "")
+    next_url = _safe_next(request)
 
     return render(
         request,