增加Django Admin中PositiveIntegerField的宽度

在Django Admin中，增加输入框宽度的正确方法是什么

更新

这些是我的文件：

型号.py

from django.db import models

class Report(models.Model):
    datum       = models.DateField(unique=True, help_text='Od koji je datuma izvjestaj.')
    osiguranika = models.PositiveIntegerField(help_text='Broj osiguranika.')
    /* lot of staf below*/

    def __unicode__(self):
        return str(self.datum)

from django import forms
from hzmo_web.apps.hzmo.models import Report

class ReportForm(forms.ModelForm):
    class Meta:
        model = Report

    def __init__(self, *args, **kw):
        super(ReportForm, self).__init__(*args, **kw)
        self.fields['osiguranika'].widget.attrs['class']  = 'form-text'

forms.py

from django.db import models

class Report(models.Model):
    datum       = models.DateField(unique=True, help_text='Od koji je datuma izvjestaj.')
    osiguranika = models.PositiveIntegerField(help_text='Broj osiguranika.')
    /* lot of staf below*/

    def __unicode__(self):
        return str(self.datum)

from django import forms
from hzmo_web.apps.hzmo.models import Report

class ReportForm(forms.ModelForm):
    class Meta:
        model = Report

    def __init__(self, *args, **kw):
        super(ReportForm, self).__init__(*args, **kw)
        self.fields['osiguranika'].widget.attrs['class']  = 'form-text'

css

.form-text{
    width:750px; 
    height:250px;
}

models.py

class Num(models.Models):
    number   = models.PositiveIntegerField()

forms.py

class NumForm(forms.ModelForm):
    class Meta:
        model = Num

    def __init__(self, *args, **kw):
        super(NumForm, self).__init__(*args, **kw)
        self.fields['number'].widget.attrs['class']  = 'form-text'

style.css

.form-text{
    width:250px; 
        height:25px;
}

管理员

class NumAdmin(AuditAdmin):
    form = NumForm
    list_display         = ('number', )

    class Media:
        css = {
             'all': (/style.css',) 
        }

---

我试过了，但不起作用。我把forms.py和css放在同一个文件夹中，其中是我的model.py。我应该把它放在别的地方吗，还是还有更多的事情要做？你也可以把一些关于你的回应的博客文章、文章或文档链接起来。谢谢，我已经用我的文件内容更新了我的帖子。如果你能看一下，那就太好了。据我所知，重要的是设置form=NumForm。我还有几个问题：1。你用的是AuditAdmin，我用的是ModelAdmin。有什么区别？。我创建了静态目录，并将may css放在那里。在admin.py中导入您的NumForm