Как создать кастомную форму?

.some-class input[type="text"] {
    width: 100%;
}
.some-class input[name="some_input"] {
    border: 1px solid red;
}

<form class="some-class">
    {{ form }}
</form>

class SomeForm(forms.Form):
    some_input = forms.CharField(label='Какое-то поле', widget=forms.TextInput(attrs={'class': 'some-class'}))