Align Checkbox inside a <div> - html

Question

I seem to be having a strange problem which I can't fully understand.
This is my html:
<div class="menu">
Por favor seleccione os conteúdos:
<br/>
<br/>
<br/>
Nome:
<input name="Nome" class="checkbox" type="checkbox" value="Nome" checked />
<br/>
<br/>
Data:
<input name="Data" class="checkbox" type="checkbox" value="Data" checked />
<br/>
<br/>
Cliente:
<input name="Cliente" class="checkbox" type="checkbox" value="Cliente" checked />
<br/>
<br/>
Observações:
<input name="Observações" class="checkbox" type="checkbox" value="Observações" checked />
</div>
Inside an Html page with nothing else except the default stuff from Dreamweaver, placed inside the body.
With this CSS attached:
#charset "UTF-8";
/* CSS Document */
.menu
{
width:300px;
margin-left: auto;
margin-right: auto;
padding:10px;
border: 1px solid #000;
}
.checkbox {
float:right;
}
Now this code renders properly in Safari, text on the left and check boxes aligned on the right inside a div.
In Firefox it does not.
The checkboxes seem like they dropped a line.
It seems to be related to a problem I can't understand, but If the checkbox comes first like:
<br/>
<input name="Cliente" class="checkbox" type="checkbox" value="Cliente" checked />Cliente:
<br/>
It renders the intended way in Firefox although as expected its not good on Safari.
I can't seem to find what's causing the line drop.

Answer 1

Floats only affect code that follows them in the html. Since you have the input after the label, it will be floated right but on a new line. Different browsers render <br> in different ways.
A good cross-browser way to do checkboxes is
.cb-row {margin: 10px;clear:both;overflow:hidden;}
.cb-row label {float:left;}
.cb-row input {float:right;}
<div class="menu">
Por favor seleccione os conteúdos:
<div class="cb-row">
<label for="nome">Nome:</label>
<input id="nome" name="Nome" type="checkbox" value="Nome" checked />
</div>
<div class="cb-row">
<label for="data">Data:</label>
<input id="data" name="Data" type="checkbox" value="Data" checked />
</div>
<div class="cb-row">
<label for="cliente">Cliente:</label>
<input id="cliente" name="Cliente" type="checkbox" value="Cliente" checked />
</div>
<div class="cb-row">
<label for="ob">Observações:</label>
<input id="ob" name="Observações" type="checkbox" value="Observações" checked />
</div>
</div>
The label is floated left and the checkbox is floated right. They are contained in a row div that controls the margins between rows. I removed the class= from the input and instead styled the input in .cb-row input
An advantage of using label with the for= and input with the matching id=, is that when you click on the label, the checkbox will be selected/unselected.