[Android] Problem with search input in subheader

Hi, i’m new to ionic/cordova dev and i’m facing a problem with this simple code :

<div class="bar bar-subheader item-input-inset">
  <label class="item-input-wrapper input-search">
        <i class="icon ion-ios7-search placeholder-icon"></i>
        <input id="searchKey" type="search" placeholder="Search" ng-model="searchKey" autocorrect="off">
  </label>
  <button class="button button-positive button-search" ng-click="search()">
        <i class="icon ion-search"></i>
   </button>
</div>

How it looks like on my android emulator :

I expected the search input and the button to fit well in the subheader. Is there something I didn’t understand right ? How can I fix this search input width ? (I can fix the button position by adding margin properties but if there is a better idea I’d like to know).

Thanks in advance !