Loss of pixels in input from one form and another not

Question

I got the following input

<label class="labelPequeno">Endereço</label>
<input type="text" class="typeTextGrande" 
required maxlength="400" id="endereco" name="endereco" />

With class="typeTextGrande"

CSS

.typeTextGrande, .typeTextMedio, .typeTextPequeno {
    height: 36px;
    padding: 4px;
}
.typeTextPequeno {
    width: 100px;
}
.typeTextMedio {
    width: 200px;
}
.typeTextGrande {
    width: 550px;
}
label {
    height: 40px;
    line-height: 40px;
    display: inline-block;
    vertical-align: middle;
}
.labelPequeno {
    width: 100px;
}
.labelMedio {
    width: 200px;
}
.labelGrande {
    width: 300px;
}

It turns out that this input is part of a customer registration form that exists both in the ambiente administrativo how much in the ambiente do cliente. And when I "Inspect" the element in the two forms I notice that in the administrative environment there is some loss exatamente of 12px so much on the width how much in the height of all elements.

But I don’t think these 12px.