Merge branch 'css-shorthand' into 'master'

Follow the CSS Style Guide rules for using shorthand where possible.

Fixes violations of the Shorthand rule. All of these were done manually and I reviewed each change to verify, so they should all be right.

Discussed in #14299.

cc: @jschatz1 

See merge request !3313

app/assets/stylesheets/framework/blocks.scss

@@ -107,7 +107,7 @@
     margin: 0;
     font-size: 23px;
     font-weight: normal;
-    margin: 16px 0 5px 0;
+    margin: 16px 0 5px;
     color: #4c4e54;
     font-size: 23px;
     line-height: 1.1;

app/assets/stylesheets/framework/dropdowns.scss

@@ -75,7 +75,7 @@
   width: 240px;
   margin-top: 2px;
   margin-bottom: 0;
-  padding: 10px 10px;
+  padding: 10px;
   font-size: 14px;
   font-weight: normal;
   background-color: $dropdown-bg;

app/assets/stylesheets/framework/layout.scss

@@ -16,7 +16,7 @@ body {
 }
 
 .container .content {
-  margin: 0 0;
+  margin: 0;
 }
 
 .navless-container {

app/assets/stylesheets/framework/typography.scss

@@ -39,8 +39,8 @@
   h1 {
     font-size: 1.3em;
     font-weight: 600;
-    margin: 24px 0 12px 0;
-    padding: 0 0 10px 0;
+    margin: 24px 0 12px;
+    padding: 0 0 10px;
     border-bottom: 1px solid #e7e9ed;
     color: #313236;
   }
@@ -48,27 +48,27 @@
   h2 {
     font-size: 1.2em;
     font-weight: 600;
-    margin: 24px 0 12px 0;
+    margin: 24px 0 12px;
     color: #313236;
   }
 
   h3 {
-    margin: 24px 0 12px 0;
+    margin: 24px 0 12px;
     font-size: 1.1em;
   }
 
   h4 {
-    margin: 24px 0 12px 0;
+    margin: 24px 0 12px;
     font-size: 0.98em;
   }
 
   h5 {
-    margin: 24px 0 12px 0;
+    margin: 24px 0 12px;
     font-size: 0.95em;
   }
 
   h6 {
-    margin: 24px 0 12px 0;
+    margin: 24px 0 12px;
     font-size: 0.90em;
   }
 
@@ -76,7 +76,7 @@
     color: #7f8fa4;
     font-size: inherit;
     padding: 8px 21px;
-    margin: 12px 0 12px;
+    margin: 12px 0;
     border-left: 3px solid #e7e9ed;
   }
 
@@ -88,13 +88,13 @@
 
   p {
     color: #5c5d5e;
-    margin: 6px 0 0 0;
+    margin: 6px 0 0;
   }
 
   table {
     @extend .table;
     @extend .table-bordered;
-    margin: 12px 0 12px 0;
+    margin: 12px 0;
     color: #5c5d5e;
     th {
       background: #f8fafc;
@@ -102,7 +102,7 @@
   }
 
   pre {
-    margin: 12px 0 12px 0;
+    margin: 12px 0;
     font-size: 13px;
     line-height: 1.6em;
     overflow-x: auto;
@@ -191,7 +191,7 @@ body {
   line-height: 1.3;
   font-size: 1.25em;
   font-weight: 600;
-  margin: 12px 7px 12px 7px;
+  margin: 12px 7px;
 }
 
 h1, h2, h3, h4, h5, h6 {

app/assets/stylesheets/pages/diff.scss

@@ -132,7 +132,7 @@
     }
     .image-info {
       font-size: 12px;
-      margin: 5px 0 0 0;
+      margin: 5px 0 0;
       color: grey;
     }
 

app/assets/stylesheets/pages/issuable.scss

@@ -183,7 +183,7 @@
     .block {
       width: $sidebar_collapsed_width - 1px;
       margin-left: -19px;
-      padding: 15px 0 0 0;
+      padding: 15px 0 0;
       border-bottom: none;
       overflow: hidden;
     }
@@ -273,12 +273,12 @@
 }
 
 .participants-list {
-  margin: -5px -5px;
+  margin: -5px;
 }
 
 .participants-author {
   display: inline-block;
-  padding: 5px 5px;
+  padding: 5px;
 
   .author_link {
     display: block;

app/assets/stylesheets/pages/login.scss

@@ -45,7 +45,7 @@
     .login-heading h3 {
       font-weight: 300;
       line-height: 1.5;
-      margin: 0 0 10px 0;
+      margin: 0 0 10px;
     }
 
     .login-footer {

app/assets/stylesheets/pages/profile.scss

@@ -54,7 +54,7 @@
 }
 
 .account-well {
-  padding: 10px 10px;
+  padding: 10px;
   background-color: $help-well-bg;
   border: 1px solid $help-well-border;
   border-radius: $border-radius-base;

app/assets/stylesheets/pages/projects.scss

@@ -333,7 +333,7 @@ pre.light-well {
 }
 
 .git-empty {
-  margin: 0 7px 0 7px;
+  margin: 0 7px;
 
   h5 {
     color: #5c5d5e;

app/assets/stylesheets/pages/stat_graph.scss

@@ -16,7 +16,7 @@
 
 #contributors {
   .contributors-list {
-    margin: 0 0 10px 0;
+    margin: 0 0 10px;
     list-style: none;
     padding: 0;
   }