[SalesForce] VisualForce page with SLDS: apex:inputField lookup button way too big

I have the following piece of code:

<div class="slds-p-horizontal--small slds-size--5-of-12">
    <label class="slds-form-element__label" for="select-01">Campaign</label>
    <div class="slds-form-element__control">
        <apex:inputField value="{!campaignLookup}" styleClass="slds-input"/>    
    </div>
</div>

It's all working as intended, except there is one style issue.

If I remove the styleClass, then the lookup button still works, it just looks hideous.

If I add the styleClass, it looks just like SLDS (in fact, it IS slds), and I get a text field that is 5-of-12 width, and a button besides it which opens a lookup window.
This button is ALSO 5-of-12 width, meaning I have twice the intended size (simply put: it's WAY too big).

How do I fix it so that I have only once a 5-of-12 size? I don't care if the textfield is 5-of-12 and the button is just slightly over the border, but I don't want the button to have an enormous div for only 32*32 pixels ever.

Edit: Fix:

<style>
    .lookupInput a { 
        border: none !important;
        width: 60px !important ;
    }
</style>

This removes the border and sets the width of the lookup icon to precisely 60 pixels, instead of the enormous div the text field also has.

Best Answer

Lightning design system do not supports apex input filed. Try to create custom CSS styles for lookups and other field types