How to set CSS attributes to default values for a specific element (or prevent inheritance)

in your case you can use that :

.navigation input {    
    all: initial;
}

it will revert all attibutes of your input to initial value.

source : http://www.w3schools.com/cssref/css3_pr_all.asp

If you are saying about the browser defaults than look at CSS reset stylesheets, they are all over the web, those stylesheets reset each elements properties to a standardized value.

Few Examples

Meyer Web

HTML5 Doctor (CSS Reset With HTML5 Elements Included)

If you are saying manual style resets and ignore inheritance, than until now, there's no way to reset the styles completely unless and until you re-declare their values so for example

div {
   color: red;
   font-family: Arial;
}

div p {
   /* Here it will inherit the parents child unless and 
      until you re specify properties with different values */
}

CSS 4 CR has a provision for the revert keyword for values. It looks like intended for the exact purpose in the question and might be used like this:

.navigation input {    
    all: revert;
}

Still its browser support is not very impressive for the time of writing...