From 37c976499ead51c1d88e8e8213366240a72adebc Mon Sep 17 00:00:00 2001
From: Cotes Chung <11371340+cotes2020@users.noreply.github.com>
Date: Wed, 2 Aug 2023 05:18:35 +0800
Subject: [PATCH] perf(ui): improve web accessibility (#447)

- Make color and contrast meets WCAG 2 AA and above
- Fixes `aria-label` on button "copy link" in posts
---
 _includes/post-sharing.html                 |  8 ++--
 _javascript/modules/components/clipboard.js | 10 ++++-
 _sass/addon/commons.scss                    | 18 +++++----
 _sass/addon/module.scss                     |  7 +++-
 _sass/addon/syntax.scss                     |  1 +
 _sass/colors/dark-syntax.scss               | 36 ++++++++---------
 _sass/colors/dark-typography.scss           | 10 ++---
 _sass/colors/light-syntax.scss              | 45 +++++++++++----------
 _sass/colors/light-typography.scss          | 14 +++----
 _sass/layout/post.scss                      | 29 ++++++-------
 10 files changed, 95 insertions(+), 83 deletions(-)

diff --git a/_includes/post-sharing.html b/_includes/post-sharing.html
index f607ba203cc..40852708c6b 100644
--- a/_includes/post-sharing.html
+++ b/_includes/post-sharing.html
@@ -22,14 +22,16 @@
       </a>
     {% endfor %}
 
-    <i
+    <button
       id="copy-link"
-      class="fa-fw fas fa-link small"
+      aria-label="Copy link"
+      class="btn small"
       data-bs-toggle="tooltip"
       data-bs-placement="top"
       title="{{ site.data.locales[include.lang].post.button.share_link.title }}"
       data-title-succeed="{{ site.data.locales[include.lang].post.button.share_link.succeed }}"
     >
-    </i>
+      <i class="fa-fw fas fa-link pe-none"></i>
+    </button>
   </span>
 </div>
diff --git a/_javascript/modules/components/clipboard.js b/_javascript/modules/components/clipboard.js
index f8038430f65..f4634cf3a58 100644
--- a/_javascript/modules/components/clipboard.js
+++ b/_javascript/modules/components/clipboard.js
@@ -99,7 +99,9 @@ export function initClipboard() {
 
   /* --- Post link sharing --- */
 
-  $('#copy-link').on('click', (e) => {
+  const btnCopyLink = $('#copy-link');
+
+  btnCopyLink.on('click', (e) => {
     let target = $(e.target);
 
     if (isLocked(target)) {
@@ -120,4 +122,10 @@ export function initClipboard() {
       }, TIMEOUT);
     });
   });
+
+  btnCopyLink.on('mouseleave', function (e) {
+    const target = $(e.target);
+    target.tooltip('hide');
+    console.log('mouse leave...');
+  });
 }
diff --git a/_sass/addon/commons.scss b/_sass/addon/commons.scss
index 86b48991574..fd2dfde51cf 100644
--- a/_sass/addon/commons.scss
+++ b/_sass/addon/commons.scss
@@ -176,6 +176,8 @@ footer {
   font-size: 0.8rem;
   background-color: var(--main-bg);
 
+  @extend %text-color;
+
   div.d-flex {
     height: $footer-height;
     line-height: 1.2rem;
@@ -185,7 +187,7 @@ footer {
   }
 
   a {
-    @extend %text-color;
+    @extend %text-highlight;
 
     &:hover {
       @extend %link-hover;
@@ -243,7 +245,6 @@ i {
   .post-tag {
     line-height: 1.05rem;
     font-size: 0.85rem;
-    border: 1px solid var(--btn-border-color);
     border-radius: 0.8rem;
     padding: 0.3rem 0.5rem;
     margin: 0 0.35rem 0.5rem 0;
@@ -494,9 +495,10 @@ i {
   display: inline-block;
   min-width: 2rem;
   text-align: center;
-  border-radius: 0.3rem;
+  border-radius: 0.5rem;
+  border: 1px solid var(--btn-border-color);
   padding: 0 0.4rem;
-  color: inherit;
+  color: var(--text-muted-color);
   line-height: 1.3rem;
 
   &:not(:last-child) {
@@ -745,19 +747,20 @@ $btn-mb: 0.5rem;
     font-size: 1.75rem;
     line-height: 1.2;
     letter-spacing: 0.25px;
-    color: rgba(134, 133, 133, 0.99);
     margin-top: 1.25rem;
     margin-bottom: 0.5rem;
 
     a {
       @extend %clickable-transition;
       @extend %sidebar-link-hover;
+
+      color: var(--site-title-color);
     }
   }
 
   .site-subtitle {
     font-size: 95%;
-    color: var(--sidebar-muted-color);
+    color: var(--site-subtitle-color);
     margin-top: 0.25rem;
     word-spacing: 1px;
     -webkit-user-select: none;
@@ -915,7 +918,7 @@ $btn-mb: 0.5rem;
 
   #breadcrumb {
     font-size: 1rem;
-    color: gray;
+    color: var(--text-muted-color);
     padding-left: 0.5rem;
 
     a:hover {
@@ -1102,7 +1105,6 @@ $btn-mb: 0.5rem;
 /* --- main wrapper --- */
 
 #main-wrapper {
-  background-color: var(--main-bg);
   position: relative;
   min-height: calc(100vh - $footer-height-mobile);
 
diff --git a/_sass/addon/module.scss b/_sass/addon/module.scss
index 10e0d69ceb9..a7e5e068d04 100644
--- a/_sass/addon/module.scss
+++ b/_sass/addon/module.scss
@@ -107,7 +107,7 @@
 }
 
 %sidebar-links {
-  color: rgba(117, 117, 117, 0.9);
+  color: var(--sidebar-muted-color);
   -webkit-user-select: none;
   -moz-user-select: none;
   -ms-user-select: none;
@@ -122,6 +122,11 @@
   -webkit-box-orient: vertical;
 }
 
+%text-highlight {
+  color: inherit;
+  font-weight: 600;
+}
+
 /* ---------- scss mixin --------- */
 
 @mixin mt-mb($value) {
diff --git a/_sass/addon/syntax.scss b/_sass/addon/syntax.scss
index df756a7b101..182b95f08b7 100644
--- a/_sass/addon/syntax.scss
+++ b/_sass/addon/syntax.scss
@@ -63,6 +63,7 @@ html {
     font-size: $code-font-size;
     line-height: 1.4rem;
     word-wrap: normal; /* Fixed Safari overflow-x */
+    color: var(--code-snippets-color);
   }
 
   table {
diff --git a/_sass/colors/dark-syntax.scss b/_sass/colors/dark-syntax.scss
index 36e96511094..f14c5207c50 100644
--- a/_sass/colors/dark-syntax.scss
+++ b/_sass/colors/dark-syntax.scss
@@ -5,44 +5,40 @@
 @mixin dark-syntax {
   --language-border-color: rgba(84, 83, 83, 0.27);
   --highlight-bg-color: #252525;
-  --highlighter-rouge-color: #de6b18;
-  --highlight-lineno-color: #6c6c6d;
+  --highlighter-rouge-color: #ff6e4e;
+  --highlight-lineno-color: #666666;
   --inline-code-bg: #272822;
   --code-header-text-color: #6a6a6a;
   --code-header-muted-color: rgb(60, 60, 60);
   --code-header-icon-color: rgb(86, 86, 86);
   --clipboard-checked-color: #2bcc2b;
-  --filepath-text-color: #bdbdbd;
-
-  /* override Bootstrap */
-  pre {
-    color: #bfbfbf;
-  }
+  --filepath-text-color: #cacaca;
+  --code-snippets-color: #c2c2c2;
 
   .highlight .gp {
-    color: #818c96;
+    color: #87939d;
   }
 
   /* syntax highlight colors from https://raw.githubusercontent.com/jwarby/pygments-css/master/monokai.css */
 
   .highlight pre { background-color: var(--highlight-bg-color); }
   .highlight .hll { background-color: var(--highlight-bg-color); }
-  .highlight .c { color: #75715e; } /* Comment */
+  .highlight .c { color: #938d75; } /* Comment */
   .highlight .err { color: #960050; background-color: #1e0010; } /* Error */
   .highlight .k { color: #66d9ef; } /* Keyword */
   .highlight .l { color: #ae81ff; } /* Literal */
   .highlight .n { color: #f8f8f2; } /* Name */
-  .highlight .o { color: #f92672; } /* Operator */
+  .highlight .o { color: #ff329c; } /* Operator */
   .highlight .p { color: #f8f8f2; } /* Punctuation */
-  .highlight .cm { color: #75715e; } /* Comment.Multiline */
-  .highlight .cp { color: #75715e; } /* Comment.Preproc */
-  .highlight .c1 { color: #75715e; } /* Comment.Single */
-  .highlight .cs { color: #75715e; } /* Comment.Special */
+  .highlight .cm { color: #938d75; } /* Comment.Multiline */
+  .highlight .cp { color: #938d75; } /* Comment.Preproc */
+  .highlight .c1 { color: #938d75; } /* Comment.Single */
+  .highlight .cs { color: #938d75; } /* Comment.Special */
   .highlight .ge { color: inherit; font-style: italic; } /* Generic.Emph */
   .highlight .gs { font-weight: bold; } /* Generic.Strong */
   .highlight .kc { color: #66d9ef; } /* Keyword.Constant */
   .highlight .kd { color: #66d9ef; } /* Keyword.Declaration */
-  .highlight .kn { color: #f92672; } /* Keyword.Namespace */
+  .highlight .kn { color: #ff329c; } /* Keyword.Namespace */
   .highlight .kp { color: #66d9ef; } /* Keyword.Pseudo */
   .highlight .kr { color: #66d9ef; } /* Keyword.Reserved */
   .highlight .kt { color: #66d9ef; } /* Keyword.Type */
@@ -61,9 +57,9 @@
   .highlight .nn { color: #f8f8f2; } /* Name.Namespace */
   .highlight .nx { color: #a6e22e; } /* Name.Other */
   .highlight .py { color: #f8f8f2; } /* Name.Property */
-  .highlight .nt { color: #f92672; } /* Name.Tag */
+  .highlight .nt { color: #ff329c; } /* Name.Tag */
   .highlight .nv { color: #f8f8f2; } /* Name.Variable */
-  .highlight .ow { color: #f92672; } /* Operator.Word */
+  .highlight .ow { color: #ff329c; } /* Operator.Word */
   .highlight .w { color: #f8f8f2; } /* Text.Whitespace */
   .highlight .mf { color: #ae81ff; } /* Literal.Number.Float */
   .highlight .mh { color: #ae81ff; } /* Literal.Number.Hex */
@@ -85,7 +81,7 @@
   .highlight .vg { color: #f8f8f2; } /* Name.Variable.Global */
   .highlight .vi { color: #f8f8f2; } /* Name.Variable.Instance */
   .highlight .il { color: #ae81ff; } /* Literal.Number.Integer.Long */
-  .highlight .gu { color: #75715e; } /* Generic.Subheading & Diff Unified/Comment? */
-  .highlight .gd { color: #f92672; background-color: #561c08; } /* Generic.Deleted & Diff Deleted */
+  .highlight .gu { color: #938d75; } /* Generic.Subheading & Diff Unified/Comment? */
+  .highlight .gd { color: #ff329c; background-color: #561c08; } /* Generic.Deleted & Diff Deleted */
   .highlight .gi { color: #a6e22e; background-color: #0b5858; } /* Generic.Inserted & Diff Inserted */
 }
diff --git a/_sass/colors/dark-typography.scss b/_sass/colors/dark-typography.scss
index 310828eb68c..715fbd91b31 100644
--- a/_sass/colors/dark-typography.scss
+++ b/_sass/colors/dark-typography.scss
@@ -10,10 +10,11 @@
 
   /* Common color */
   --text-color: rgb(175, 176, 177);
-  --text-muted-color: rgb(107, 116, 124);
+  --text-muted-color: rgb(125, 136, 146);
   --heading-color: #cccccc;
+  --label-color: #a4a4c2;
   --blockquote-border-color: rgb(66, 66, 66);
-  --blockquote-text-color: rgb(117, 117, 117);
+  --blockquote-text-color: #868686;
   --link-color: rgb(138, 180, 248);
   --link-underline-color: rgb(82, 108, 150);
   --button-bg: rgb(39, 40, 43);
@@ -22,7 +23,6 @@
   --btn-backtotop-border-color: var(--btn-border-color);
   --btn-box-shadow: var(--main-bg);
   --card-header-bg: rgb(48, 48, 48);
-  --label-color: rgb(108, 117, 125);
   --checkbox-color: rgb(118, 120, 121);
   --checkbox-checked-color: var(--link-color);
   --img-bg: radial-gradient(circle, rgb(22, 22, 24) 0%, rgb(32, 32, 32) 100%);
@@ -34,6 +34,8 @@
   );
 
   /* Sidebar */
+  --site-title-color: #717070;
+  --site-subtitle-color: #6d6c6b;
   --sidebar-bg: radial-gradient(circle, #242424 0%, #1d1f27 100%);
   --sidebar-muted-color: #6d6c6b;
   --sidebar-active-color: rgb(255, 255, 255, 0.95);
@@ -58,7 +60,6 @@
 
   /* Posts */
   --toc-highlight: rgb(116, 178, 243);
-  --tag-bg: rgb(41, 40, 40);
   --tag-hover: rgb(43, 56, 62);
   --tb-odd-bg: rgba(42, 47, 53, 0.52); /* odd rows of the posts' table */
   --tb-even-bg: rgb(31, 31, 34); /* even rows of the posts' table */
@@ -66,7 +67,6 @@
   --footnote-target-bg: rgb(63, 81, 181);
   --btn-share-color: #6c757d;
   --btn-share-hover-color: #bfc1ca;
-  --relate-post-date: var(--text-muted-color);
   --card-bg: #1e1e1e;
   --card-hovor-bg: #464d51;
   --card-shadow: rgb(21, 21, 21, 0.72) 0 6px 18px 0,
diff --git a/_sass/colors/light-syntax.scss b/_sass/colors/light-syntax.scss
index 040a5f50c50..e966312b344 100644
--- a/_sass/colors/light-syntax.scss
+++ b/_sass/colors/light-syntax.scss
@@ -3,22 +3,22 @@
  */
 
 @mixin light-syntax {
-  /* see: <https://raw.githubusercontent.com/jwarby/pygments-css/master/github.css> */
+  /* based on: <https://raw.githubusercontent.com/jwarby/pygments-css/master/github.css> */
   .highlight .hll { background-color: #ffffcc; }
-  .highlight .c { color: #999988; font-style: italic; } /* Comment */
+  .highlight .c { color: #717165; font-style: italic; } /* Comment */
   .highlight .err { color: #a61717; background-color: #e3d2d2; } /* Error */
   .highlight .k { color: #000000; font-weight: bold; } /* Keyword */
   .highlight .o { color: #000000; font-weight: bold; } /* Operator */
-  .highlight .cm { color: #999988; font-style: italic; } /* Comment.Multiline */
-  .highlight .cp { color: #999999; font-weight: bold; font-style: italic; } /* Comment.Preproc */
-  .highlight .c1 { color: #999988; font-style: italic; } /* Comment.Single */
-  .highlight .cs { color: #999999; font-weight: bold; font-style: italic; } /* Comment.Special */
+  .highlight .cm { color: #717165; font-style: italic; } /* Comment.Multiline */
+  .highlight .cp { color: #707070; font-style: italic; } /* Comment.Preproc */
+  .highlight .c1 { color: #717165; font-style: italic; } /* Comment.Single */
+  .highlight .cs { color: #707070; font-weight: bold; font-style: italic; } /* Comment.Special */
   .highlight .gd { color: #d01040; background-color: #ffdddd; } /* Generic.Deleted */
   .highlight .ge { color: #000000; font-style: italic; } /* Generic.Emph */
   .highlight .gr { color: #aa0000; } /* Generic.Error */
-  .highlight .gh { color: #999999; } /* Generic.Heading */
-  .highlight .gi { color: #008080; background-color: #ddffdd; } /* Generic.Inserted */
-  .highlight .go { color: #888888; } /* Generic.Output */
+  .highlight .gh { color: #707070; } /* Generic.Heading */
+  .highlight .gi { color: #005e5e; background-color: #ddffdd; } /* Generic.Inserted */
+  .highlight .go { color: #707070; } /* Generic.Output */
   .highlight .gp { color: #555555; } /* Generic.Prompt */
   .highlight .gs { font-weight: bold; } /* Generic.Strong */
   .highlight .gu { color: #aaaaaa; } /* Generic.Subheading */
@@ -31,10 +31,10 @@
   .highlight .kt { color: #445588; font-weight: bold; } /* Keyword.Type */
   .highlight .m { color: #009999; } /* Literal.Number */
   .highlight .s { color: #d01040; } /* Literal.String */
-  .highlight .na { color: #008080; } /* Name.Attribute */
-  .highlight .nb { color: #0086b3; } /* Name.Builtin */
+  .highlight .na { color: #005e5e; } /* Name.Attribute */
+  .highlight .nb { color: #0078a1; } /* Name.Builtin */
   .highlight .nc { color: #445588; font-weight: bold; } /* Name.Class */
-  .highlight .no { color: #008080; } /* Name.Constant */
+  .highlight .no { color: #005e5e; } /* Name.Constant */
   .highlight .nd { color: #3c5d5d; font-weight: bold; } /* Name.Decorator */
   .highlight .ni { color: #800080; } /* Name.Entity */
   .highlight .ne { color: #990000; font-weight: bold; } /* Name.Exception */
@@ -42,7 +42,7 @@
   .highlight .nl { color: #990000; font-weight: bold; } /* Name.Label */
   .highlight .nn { color: #555555; } /* Name.Namespace */
   .highlight .nt { color: #000080; } /* Name.Tag */
-  .highlight .nv { color: #008080; } /* Name.Variable */
+  .highlight .nv { color: #005e5e; } /* Name.Variable */
   .highlight .ow { color: #000000; font-weight: bold; } /* Operator.Word */
   .highlight .w { color: #bbbbbb; } /* Text.Whitespace */
   .highlight .mf { color: #009999; } /* Literal.Number.Float */
@@ -60,22 +60,23 @@
   .highlight .sr { color: #009926; } /* Literal.String.Regex */
   .highlight .s1 { color: #d01040; } /* Literal.String.Single */
   .highlight .ss { color: #990073; } /* Literal.String.Symbol */
-  .highlight .bp { color: #999999; } /* Name.Builtin.Pseudo */
-  .highlight .vc { color: #008080; } /* Name.Variable.Class */
-  .highlight .vg { color: #008080; } /* Name.Variable.Global */
-  .highlight .vi { color: #008080; } /* Name.Variable.Instance */
+  .highlight .bp { color: #707070; } /* Name.Builtin.Pseudo */
+  .highlight .vc { color: #005e5e; } /* Name.Variable.Class */
+  .highlight .vg { color: #005e5e; } /* Name.Variable.Global */
+  .highlight .vi { color: #005e5e; } /* Name.Variable.Instance */
   .highlight .il { color: #009999; } /* Literal.Number.Integer.Long */
 
   /* --- custom light colors --- */
   --language-border-color: rgba(172, 169, 169, 0.2);
-  --highlight-bg-color: #f7f7f7;
+  --highlight-bg-color: #fcfcfc;
   --highlighter-rouge-color: #3f596f;
-  --highlight-lineno-color: #c2c6cc;
+  --highlight-lineno-color: #959595;
   --inline-code-bg: #f6f6f7;
-  --code-header-text-color: #a3a3b1;
-  --code-header-muted-color: #ebebeb;
-  --code-header-icon-color: #d1d1d1;
+  --code-header-text-color: #a3a3a3;
+  --code-header-muted-color: #e2e1e1;
+  --code-header-icon-color: #c9c8c8;
   --clipboard-checked-color: #43c743;
+  --code-snippets-color: #b01662;
 
   [class^='prompt-'] {
     --inline-code-bg: #fbfafa;
diff --git a/_sass/colors/light-typography.scss b/_sass/colors/light-typography.scss
index 9fc8162aeab..07c31dbc77e 100644
--- a/_sass/colors/light-typography.scss
+++ b/_sass/colors/light-typography.scss
@@ -10,10 +10,11 @@
 
   /* Common color */
   --text-color: #34343c;
-  --text-muted-color: #8e8e8e;
+  --text-muted-color: #757575;
   --heading-color: black;
+  --label-color: #4d4d5b;
   --blockquote-border-color: #eeeeee;
-  --blockquote-text-color: #9a9a9a;
+  --blockquote-text-color: #757575;
   --link-color: #0153ab;
   --link-underline-color: #dee2e6;
   --button-bg: #ffffff;
@@ -36,8 +37,10 @@
   );
 
   /* Sidebar */
+  --site-title-color: rgb(113, 113, 113);
+  --site-subtitle-color: #717171;
   --sidebar-bg: #f6f8fa;
-  --sidebar-muted-color: #a2a19f;
+  --sidebar-muted-color: #545454;
   --sidebar-active-color: #1d1d1d;
   --sidebar-hover-bg: rgb(223, 233, 241, 0.64);
   --sidebar-btn-bg: white;
@@ -60,16 +63,13 @@
   --btn-text-color: #676666;
 
   /* Posts */
-  --toc-highlight: #563d7c;
+  --toc-highlight: #47566c;
   --btn-share-hover-color: var(--link-color);
   --card-bg: white;
   --card-hovor-bg: #e2e2e2;
   --card-shadow: rgb(104, 104, 104, 0.05) 0 2px 6px 0,
     rgba(211, 209, 209, 0.15) 0 0 0 1px;
-  --label-color: #616161;
-  --relate-post-date: rgba(30, 55, 70, 0.4);
   --footnote-target-bg: lightcyan;
-  --tag-bg: rgba(0, 0, 0, 0.075);
   --tag-border: #dee2e6;
   --tag-shadow: var(--btn-border-color);
   --tag-hover: rgb(222, 226, 230);
diff --git a/_sass/layout/post.scss b/_sass/layout/post.scss
index 3d01b4d65d0..15ea607136e 100644
--- a/_sass/layout/post.scss
+++ b/_sass/layout/post.scss
@@ -52,10 +52,10 @@ h1 + .post-meta {
   }
 
   em {
-    @extend %text-color;
+    color: var(--text-color);
 
     a {
-      @extend %text-color;
+      color: inherit;
     }
   }
 }
@@ -73,7 +73,7 @@ h1 + .post-meta {
     line-height: 1.2rem;
 
     > a {
-      color: var(--text-color);
+      @extend %text-highlight;
 
       &:hover {
         @extend %link-hover;
@@ -99,15 +99,18 @@ h1 + .post-meta {
     .share-icons {
       font-size: 1.2rem;
 
-      > i {
+      > *:hover {
+        i {
+          @extend %btn-share-hovor;
+        }
+      }
+
+      button {
         position: relative;
-        bottom: 1px;
+        bottom: 2px;
+        padding: 0;
 
         @extend %cursor-pointer;
-
-        &:hover {
-          @extend %btn-share-hovor;
-        }
       }
 
       a {
@@ -117,10 +120,6 @@ h1 + .post-meta {
 
         &:hover {
           text-decoration: none;
-
-          > i {
-            @extend %btn-share-hovor;
-          }
         }
       }
 
@@ -157,8 +156,6 @@ h1 + .post-meta {
   line-height: 2rem;
 
   .post-tag {
-    background: var(--tag-bg);
-
     &:hover {
       @extend %link-hover;
       @extend %tag-hover;
@@ -334,7 +331,7 @@ h1 + .post-meta {
   em {
     @extend %normal-font-style;
 
-    color: var(--relate-post-date);
+    color: var(--text-muted-color);
   }
 
   p {