refactor(main): begin extracting styles from main.scss

public/views/modals/coinbase-tx-details.html

@@ -10,7 +10,7 @@
   </ion-header-bar>
 
   <ion-content>
-    <div class="modal-content fix-modals-touch">
+    <div class="fix-modals-touch">
       <div class="header-modal bg-gray text-center">
         <div class="p20">
           <img src="img/bought.svg" alt="bought" width="65" ng-show="(tx.type == 'buy' || (tx.type == 'send' && tx.to)) && tx.status == 'completed'">

public/views/modals/customAmount.html

@@ -9,7 +9,7 @@
   </ion-header-bar>
 
   <ion-content ng-style="{'background-color': '#f6f7f9'}">
-    <div class="modal-content fix-modals-touch">
+    <div class="fix-modals-touch">
       <div class="m20b" ng-show="customizedAmountBtc">
         <h4 class="title m0" translate>QR Code</h4>
         <ul class="no-bullet size-14 m0">

public/views/modals/wallets.html

@@ -13,7 +13,7 @@
 
   <ion-content ng-style="{'background-color': '#F6F7F9'}">
 
-    <div class="modal-content">
+    <div>
       <div class="box-notification text-center size-12 text-warning m10t" ng-show="error">
         <i class="fi-error"></i> {{error}}
       </div>