chore(header): remove all dummy-targets and update smooth scroll

assets/css/_core/_media.scss

@@ -32,7 +32,7 @@
 }
 
 @media only screen and (max-width: 960px) {
-  header.desktop {
+  #header-desktop {
     .header-wrapper {
       margin: 0 1rem;
     }
@@ -52,11 +52,11 @@
 }
 
 @media only screen and (max-width: 560px) {
-  header.desktop {
+  #header-desktop {
     display: none;
   }
 
-  header.mobile {
+  #header-mobile {
     display: block;
   }
 

assets/css/_page/_single.scss

@@ -54,13 +54,6 @@
   @import "../_partial/_single/toc";
 
   .content {
-    .post-dummy-target:target {
-      display: inline-block;
-      position: relative;
-      top: -5.6rem;
-      visibility: hidden;
-    }
-
     h1,
     h2,
     h3,
@@ -75,17 +68,6 @@
       }
     }
 
-    h2::before,
-    h3::before,
-    h4::before,
-    h5::before,
-    h6::before {
-      display: block;
-      content: "";
-      height: 1.2 * $header-height;
-      margin: -1.2 * $header-height 0 0;
-    }
-
     h2 > a:first-child::before {
       content: "#";
       margin-right: .3125rem;

assets/css/_partial/_header.scss

@@ -10,7 +10,7 @@ header {
   }
 }
 
-header.desktop {
+#header-desktop {
   display: block;
   z-index: 100;
 
@@ -45,7 +45,7 @@ header.desktop {
   }
 }
 
-header.mobile {
+#header-mobile {
   display: none;
   z-index: 100;
   transition: all 0.3s ease 0s;