Use mixins for typography instead of placeholder selectors (#9072)

Using extend would not work inside of some css, namely
inside of media queries. This made it a clear choice to
use mixins for these styles.

ui/app/components/app/modals/add-to-addressbook-modal/index.scss

@@ -9,7 +9,7 @@
     border-bottom: 1px solid $Grey-100;
 
     &__header {
-      @extend %H3;
+      @include H3;
     }
   }
 

ui/app/components/app/modals/new-account-modal/index.scss

@@ -9,7 +9,7 @@
     border-bottom: 1px solid $Grey-100;
 
     &__header {
-      @extend %H4;
+      @include H4;
 
       font-weight: bold;
       display: flex;

ui/app/components/app/permission-page-container/index.scss

@@ -31,7 +31,7 @@
   }
 
   &__title {
-    @extend %H4;
+    @include H4;
 
     line-height: 25px;
     text-align: center;
@@ -84,7 +84,7 @@
   }
 
   &__permissions-header {
-    @extend %H6;
+    @include H6;
 
     line-height: 20px;
     color: #6a737d;

ui/app/components/app/permissions-connect-footer/index.scss

@@ -5,7 +5,7 @@
   align-items: center;
 
   &__text {
-    @extend %H7;
+    @include H7;
 
     line-height: 17px;
     color: #6a737d;

ui/app/components/app/permissions-connect-header/index.scss

@@ -26,7 +26,7 @@
   }
 
   &__title {
-    @extend %H3;
+    @include H3;
 
     text-align: center;
     color: $Black-100;
@@ -35,7 +35,7 @@
 
   &__text,
   &__subtitle {
-    @extend %H6;
+    @include H6;
 
     text-align: center;
     color: $Grey-500;

ui/app/components/ui/button/buttons.scss

@@ -11,7 +11,7 @@ $hover-orange: #ffd3b5;
 $warning-light-orange: #f8b588;
 
 %button {
-  @extend %H6;
+  @include H6;
 
   font-weight: 500;
   font-family: Roboto, Arial;
@@ -34,7 +34,7 @@ $warning-light-orange: #f8b588;
 }
 
 %link {
-  @extend %H4;
+  @include H4;
 
   color: $Blue-500;
   line-height: 1.25rem;
@@ -60,7 +60,8 @@ $warning-light-orange: #f8b588;
 
 %small-link {
   @extend %link;
-  @extend %H6;
+
+  @include H6;
 }
 
 .button {

ui/app/components/ui/list-item/index.scss

@@ -5,7 +5,7 @@
   background: #fff;
   padding: 24px 16px;
 
-  @extend %Paragraph;
+  @include Paragraph;
 
   border-top: 1px solid $mercury;
   border-bottom: 1px solid $mercury;

ui/app/components/ui/popover/index.scss

@@ -33,7 +33,7 @@
       align-items: center;
       justify-content: space-between;
 
-      @extend %H4;
+      @include H4;
 
       font-weight: bold;
       line-height: 25px;
@@ -51,7 +51,7 @@
     }
 
     &__subtitle {
-      @extend %H6;
+      @include H6;
 
       line-height: 20px;
     }

ui/app/css/design-system/typography.scss

@@ -70,7 +70,7 @@ $fa-font-path: 'fonts/fontawesome';
 $font-family: Roboto, Helvetica, Arial, sans-serif;
 
 // Typography
-%H1 {
+@mixin H1 {
   font-style: normal;
   font-weight: normal;
   font-size: 2.5rem;
@@ -78,7 +78,8 @@ $font-family: Roboto, Helvetica, Arial, sans-serif;
   line-height: 140%;
 }
 
-%H2 {
+
+@mixin H2 {
   font-style: normal;
   font-weight: normal;
   font-size: 2rem;
@@ -86,7 +87,7 @@ $font-family: Roboto, Helvetica, Arial, sans-serif;
   line-height: 140%;
 }
 
-%H3 {
+@mixin H3 {
   font-style: normal;
   font-weight: normal;
   font-size: 1.5rem;
@@ -94,7 +95,7 @@ $font-family: Roboto, Helvetica, Arial, sans-serif;
   line-height: 140%;
 }
 
-%H4 {
+@mixin H4 {
   font-style: normal;
   font-weight: normal;
   font-size: 1.125rem;
@@ -102,7 +103,7 @@ $font-family: Roboto, Helvetica, Arial, sans-serif;
   line-height: 140%;
 }
 
-%H5 {
+@mixin H5 {
   font-style: normal;
   font-weight: normal;
   font-size: 1rem;
@@ -110,14 +111,14 @@ $font-family: Roboto, Helvetica, Arial, sans-serif;
   line-height: 140%;
 }
 
-%H6 {
+@mixin H6 {
   font-style: normal;
   font-weight: normal;
-  font-size: 0.875rem;
+  font-size: 0.875rem; // 14px @default
-  font-family: $font-family;
+  line-height: 140%;
 }
 
-%Paragraph {
+@mixin Paragraph {
   font-style: normal;
   font-weight: normal;
   font-size: 1rem;
@@ -125,7 +126,7 @@ $font-family: Roboto, Helvetica, Arial, sans-serif;
   line-height: 140%;
 }
 
-%H7 {
+@mixin H7 {
   font-style: normal;
   font-weight: normal;
   font-size: 0.75rem;
@@ -133,7 +134,7 @@ $font-family: Roboto, Helvetica, Arial, sans-serif;
   line-height: 140%;
 }
 
-%H8 {
+@mixin H8 {
   font-style: normal;
   font-weight: normal;
   font-size: 0.625rem;
@@ -141,7 +142,7 @@ $font-family: Roboto, Helvetica, Arial, sans-serif;
   line-height: 140%;
 }
 
-%H9 {
+@mixin H9 {
   font-style: normal;
   font-weight: normal;
   font-size: 0.5rem;

ui/app/css/itcss/components/modal.scss

@@ -287,7 +287,8 @@
   }
 
   &__button {
-    @extend %Paragraph;
+    @include Paragraph;
+
     @extend %button;
 
     width: 141px;

ui/app/pages/home/index.scss

@@ -43,7 +43,7 @@
     display: flex;
     flex-direction: column;
 
-    @extend %H6;
+    @include H6;
 
     padding-left: 24px;
     padding-right: 24px;

ui/app/pages/permissions-connect/choose-account/index.scss

@@ -24,13 +24,13 @@
 
 
   &__title {
-    @extend %H4;
+    @include H4;
   }
 
   &__text,
   &__text-blue,
   &__text-grey {
-    @extend %H6;
+    @include H6;
   }
 
   &__text-blue {
@@ -120,7 +120,7 @@
     }
 
     &__label {
-      @extend %H6;
+      @include H6;
 
       color: $Black-100;
       text-overflow: ellipsis;
@@ -129,13 +129,13 @@
     }
 
     &__balance {
-      @extend %H7;
+      @include H7;
 
       color: $Grey-500;
     }
 
     &__last-connected {
-      @extend %H8;
+      @include H8;
 
       display: flex;
       flex-direction: column;

ui/app/pages/permissions-connect/index.scss

@@ -24,7 +24,7 @@
   }
 
   &__back {
-    @extend %H6;
+    @include H6;
 
     color: $Grey-600;
     cursor: pointer;
@@ -35,7 +35,7 @@
   }
 
   &__page-count {
-    @extend %H7;
+    @include H7;
 
     color: #6a737d;
     grid-column: 2;

ui/app/pages/permissions-connect/redirect/index.scss

@@ -4,7 +4,7 @@
   justify-content: center;
 
   &__result {
-    @extend %H3;
+    @include H3;
 
     position: absolute;
     top: 30%;

ui/app/pages/send/send.scss

@@ -6,7 +6,7 @@
     padding: 14px 0 3px 0;
 
     .page-container__title {
-      @extend %H4;
+      @include H4;
 
       text-align: center;
     }
@@ -91,7 +91,7 @@
     }
 
     &__group-label {
-      @extend %H8;
+      @include H8;
 
       background-color: $Grey-000;
       color: $Grey-600;
@@ -136,7 +136,7 @@
       }
 
       &__subtitle {
-        @extend %H8;
+        @include H8;
 
         color: $Grey-500;
       }
@@ -186,7 +186,7 @@
     }
 
     &__input {
-      @extend %H6;
+      @include H6;
 
       flex: 1 1 auto;
       width: 0;