fix(style): link color and wrap style (#283)

assets/css/_mixin/_compatibility.scss

@@ -90,3 +90,9 @@
   word-wrap: $value;
   overflow-wrap: $value;
 }
+
+@mixin line-break($value) {
+  -webkit-line-break: $value;
+  -ms-line-break: $value;
+  line-break: $value;
+}

assets/css/_mixin/_link.scss

@@ -1,5 +1,5 @@
 @mixin link($light, $dark) {
-  a {
+  a, a::before, a::after {
     color: if($light, $global-link-color, $single-link-color);
 
     [theme=dark] & {

assets/css/_mixin/_summary.scss

@@ -72,29 +72,17 @@
       h5,
       h6 {
         line-height: 2;
-
-        &::before {
-          content: "|";
-          margin-right: .3125rem;
-          color: $global-link-color;
-
-          [theme=dark] & {
-            color: $global-link-color-dark;
-          }
-        }
       }
 
       h2 {
         font-size: 1.2rem;
-
-        &::before {
-          content: "#";
-        }
       }
 
-      @include link(true, true);
+      @include link(false, true);
 
       b, strong {
+        color: $global-font-secondary-color;
+
         [theme=dark] & {
           color: $global-font-secondary-color-dark;
         }