Update all CSS to use logical properties

- Vendor CSS's are excluded for now
- Removed <IE7 asterisk prefix items

_sass/minimal-mistakes/_sidebar.scss

@@ -108,12 +108,12 @@
 .splash .sidebar__right {
   @include breakpoint($large) {
     position: relative;
-    float: right;
-    margin-right: 0;
+    float: inline-end;
+    margin-inline-end: 0;
   }
 
   @include breakpoint($x-large) {
-    margin-right: 0;
+    margin-inline-end: 0;
   }
 }
 
@@ -147,15 +147,13 @@
 .author__content {
   display: table-cell;
   vertical-align: top;
-  padding-left: 15px;
-  padding-right: 25px;
+  padding-inline: 15px 25px;
   line-height: 1;
 
   @include breakpoint($large) {
     display: block;
     width: 100%;
-    padding-left: 0;
-    padding-right: 0;
+    padding-inline: 0;
   }
 
   a {
@@ -219,7 +217,7 @@
         content: '';
         position: fixed;
         top: 0;
-        left: 0;
+        inset-inline-start: 0;
         width: 100%;
         height: 100%;
         pointer-events: none;
@@ -241,7 +239,7 @@
 .author__urls {
   display: none;
   position: absolute;
-  right: 0;
+  inset-inline-end: 0;
   margin-top: 15px;
   padding: 10px;
   list-style-type: none;
@@ -265,12 +263,12 @@
     box-shadow: none;
   }
 
-  &:before {
+  &::before {
     display: block;
     content: "";
     position: absolute;
     top: -11px;
-    left: calc(50% - 10px);
+    inset-inline-start: calc(50% - 10px);
     width: 0;
     border-style: solid;
     border-width: 0 10px 10px;
@@ -287,7 +285,7 @@
     content: "";
     position: absolute;
     top: -10px;
-    left: calc(50% - 10px);
+    inset-inline-start: calc(50% - 10px);
     width: 0;
     border-style: solid;
     border-width: 0 10px 10px;
@@ -333,10 +331,10 @@
   @include breakpoint($large) {
     position: initial;
     top: initial;
-    right: initial;
+    inset-inline-end: initial;
     width: initial;
-    margin-right: initial;
-    padding-left: initial;
+    margin-inline-end: initial;
+    padding-inline-start: initial;
     z-index: initial;
 
     &.sticky {
@@ -346,6 +344,6 @@
 
   @include breakpoint($x-large) {
     width: initial;
-    margin-right: initial;
+    margin-inline-end: initial;
   }
 }