--- a/browser/components/loop/content/shared/css/common.css
+++ b/browser/components/loop/content/shared/css/common.css
@@ -76,28 +76,31 @@ p {
 
 /* A reset for all button-appearing elements, with the lowest-common
  * denominator of the needed rules.  Intended to be used as a base class
  * together with .btn-*
  */
 
 .btn {
   display: inline-block;
-  overflow: hidden;
   margin: 0;
   padding: 0;
   border: none;
   background: #a5a;
   color: #fff;
   text-align: center;
   text-decoration: none;
+  font-size: .9em;
+  cursor: pointer;
+}
+
+.btn.btn-constrained {
+  overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
-  font-size: .9em;
-  cursor: pointer;
 }
 
 .btn-info {
   background-color: #0096dd;
   border: 1px solid #0095dd;
   color: #fff;
 }
 

--- a/browser/components/loop/content/shared/css/conversation.css
+++ b/browser/components/loop/content/shared/css/conversation.css
@@ -257,17 +257,17 @@
 
 .call-action-group {
   display: flex;
   padding: 2.5em 4px 0 4px;
   width: 100%;
 }
 
 .call-action-group > .btn {
-  height: 26px;
+  min-height: 26px;
   border-radius: 2px;
   margin: 0 4px;
   min-width: 64px;
 }
 
 .call-action-group .btn-group-chevron,
 .call-action-group .btn-group {
   width: 100%;

--- a/browser/components/loop/standalone/content/js/webapp.js
+++ b/browser/components/loop/standalone/content/js/webapp.js
@@ -386,17 +386,17 @@ loop.webapp = (function($, _, OT, mozL10
       var chevronClasses = React.addons.classSet({
         "btn-chevron": true,
         "disabled": this.props.disabled
       });
       return (
         React.DOM.div({className: "standalone-btn-chevron-menu-group"}, 
           React.DOM.div({className: "btn-group-chevron"}, 
             React.DOM.div({className: "btn-group"}, 
-              React.DOM.button({className: "btn btn-large btn-accept", 
+              React.DOM.button({className: "btn btn-constrained btn-large btn-accept", 
                       onClick: this.props.startCall("audio-video"), 
                       disabled: this.props.disabled, 
                       title: mozL10n.get("initiate_audio_video_call_tooltip2")}, 
                 React.DOM.span({className: "standalone-call-btn-text"}, 
                   this.props.caption
                 ), 
                 React.DOM.span({className: "standalone-call-btn-video-icon"})
               ), 

--- a/browser/components/loop/standalone/content/js/webapp.jsx
+++ b/browser/components/loop/standalone/content/js/webapp.jsx
@@ -386,17 +386,17 @@ loop.webapp = (function($, _, OT, mozL10
       var chevronClasses = React.addons.classSet({
         "btn-chevron": true,
         "disabled": this.props.disabled
       });
       return (
         <div className="standalone-btn-chevron-menu-group">
           <div className="btn-group-chevron">
             <div className="btn-group">
-              <button className="btn btn-large btn-accept"
+              <button className="btn btn-constrained btn-large btn-accept"
                       onClick={this.props.startCall("audio-video")}
                       disabled={this.props.disabled}
                       title={mozL10n.get("initiate_audio_video_call_tooltip2")}>
                 <span className="standalone-call-btn-text">
                   {this.props.caption}
                 </span>
                 <span className="standalone-call-btn-video-icon" />
               </button>