Make letter component more responsive

src/components/Letter.vue

@@ -8,7 +8,7 @@
 
   <v-layout row wrap v-if="letter">
     <!-- Author Data -->
-    <v-flex xs6>
+    <v-flex xs12 md6>
       <v-card flat>
         <v-card-text>
           <ul style="list-style-type:none;">
@@ -21,7 +21,7 @@
     </v-flex>
 
     <!-- Images -->
-    <v-flex xs6>
+    <v-flex xs12 md6>
       <v-layout row wrap>
         <v-flex d-flex v-for="(image,i) in images" :key="i" >
           <v-card flat hover target="_blank" :href="imgfolder(image._attributes.url)">
@@ -36,7 +36,7 @@
     </v-flex>
 
     <!-- Text -->
-    <v-flex xs5>
+    <v-flex xs12 md6>
       <v-card>
         <v-card-text>
           <v-checkbox label="Montrer commentaires" v-model="showComments"></v-checkbox>
@@ -56,7 +56,7 @@
     </v-flex>
 
     <!-- Features -->
-    <v-flex xs7>
+    <v-flex xs12 md6>
       <v-expansion-panel>
         <v-expansion-panel-content v-for="feature in features" :key="feature.text">
           <div slot="header">{{feature.text}}</div>
@@ -72,7 +72,7 @@
 
   <!-- Progress Bar -->
   <v-layout v-else>
-    <v-flex xs12 >
+    <v-flex xs12>
       <v-progress-linear indeterminate color="primary"></v-progress-linear>
     </v-flex>
   </v-layout>