perf(ui): improve code snippet design

- Apply the new syntax color themes
- Center the text in the code snippet header
- Maintaining space to the left of a 3-digit line number or more

_sass/addon/syntax.scss

@@ -2,8 +2,8 @@
 * The syntax highlight.
 */
 
-@import 'colors/light-syntax';
+@import 'colors/syntax-light';
-@import 'colors/dark-syntax';
+@import 'colors/syntax-dark';
 
 html {
   @media (prefers-color-scheme: light) {
@@ -55,27 +55,35 @@ html {
   }
 
   overflow: auto;
-  padding-top: 0.5rem;
+  padding-bottom: 0.75rem;
-  padding-bottom: 1rem;
 
   pre {
     margin-bottom: 0;
     font-size: $code-font-size;
     line-height: 1.4rem;
     word-wrap: normal; /* Fixed Safari overflow-x */
-    color: var(--code-snippets-color);
   }
 
   table {
-    td pre {
+    td {
-      overflow: visible; /* Fixed iOS safari overflow-x */
+      &:first-child {
-      word-break: normal; /* Fixed iOS safari linenos code break */
+        display: inline-block;
+        margin-left: 1rem;
+        margin-right: 0.75rem;
+      }
+
+      &:last-child {
+        padding-right: 2rem !important;
+      }
+
+      pre {
+        overflow: visible; /* Fixed iOS safari overflow-x */
+        word-break: normal; /* Fixed iOS safari linenos code break */
+      }
     }
   }
 
   .lineno {
-    padding-right: 0.5rem;
-    min-width: 2.2rem;
     text-align: right;
     color: var(--highlight-lineno-color);
     -webkit-user-select: none;
@@ -90,6 +98,7 @@ code {
   -webkit-hyphens: none;
   -ms-hyphens: none;
   hyphens: none;
+  color: var(--code-color);
 
   &.highlighter-rouge {
     font-size: $code-font-size;
@@ -145,6 +154,11 @@ div[class^='language-'] {
 
     border-radius: 0;
   }
+
+  .highlight {
+    border-top-left-radius: 0;
+    border-top-right-radius: 0;
+  }
 }
 
 /* Hide line numbers for default, console, and terminal code snippets */
@@ -153,12 +167,13 @@ div {
   &.language-plaintext,
   &.language-console,
   &.language-terminal {
-    pre.lineno {
+    td:first-child {
-      display: none;
+      padding: 0 !important;
-    }
+      margin-right: 0;
 
-    td.rouge-code {
+      .lineno {
-      padding-left: 1.5rem;
+        display: none;
+      }
     }
   }
 }
@@ -166,21 +181,21 @@ div {
 .code-header {
   @extend %no-cursor;
 
-  $code-header-height: 2.25rem;
-
   display: flex;
   justify-content: space-between;
   align-items: center;
   height: $code-header-height;
-  margin-left: 1rem;
+  margin-left: 0.75rem;
   margin-right: 0.5rem;
 
   /* the label block */
   span {
+    line-height: $code-header-height;
+
     /* label icon */
     i {
       font-size: 1rem;
-      margin-right: 0.5rem;
+      width: $code-icon-width;
       color: var(--code-header-icon-color);
 
       &.small {
@@ -252,19 +267,25 @@ div {
     .code-header {
       @include ml-mr(0);
 
-      &::before {
+      $dot-margin: calc($code-header-height / 2);
-        $dot-size: 0.75rem;
-        $dot-margin: 0.5rem;
 
+      &::before {
         content: '';
         display: inline-block;
-        margin-left: 1rem;
+        margin-left: $dot-margin;
-        width: $dot-size;
+        width: $code-dot-size;
-        height: $dot-size;
+        height: $code-dot-size;
         border-radius: 50%;
         background-color: var(--code-header-muted-color);
-        box-shadow: ($dot-size + $dot-margin) 0 0 var(--code-header-muted-color),
+        box-shadow: ($code-dot-size + $code-dot-gap) 0 0
-          ($dot-size + $dot-margin) * 2 0 0 var(--code-header-muted-color);
+            var(--code-header-muted-color),
+          ($code-dot-size + $code-dot-gap) * 2 0 0
+            var(--code-header-muted-color);
+      }
+
+      span {
+        // center the text of label
+        margin-left: calc(($dot-margin + $code-dot-size) / 2 * -1);
       }
     }
   }

_sass/addon/variables.scss

@@ -20,6 +20,10 @@ $base-radius: 0.5rem;
 /* syntax highlight */
 
 $code-font-size: 0.85rem !default;
+$code-header-height: 2.25rem;
+$code-dot-size: 0.75rem;
+$code-dot-gap: 0.5rem;
+$code-icon-width: 1.75rem;
 
 /* fonts */
 

_sass/colors/dark-syntax.scss

@@ -1,87 +0,0 @@
-/*
- * The syntax dark mode styles.
- */
-
-@mixin dark-syntax {
-  --language-border-color: rgba(84, 83, 83, 0.27);
-  --highlight-bg-color: #252525;
-  --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: #cacaca;
-  --code-snippets-color: #c2c2c2;
-
-  .highlight .gp {
-    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: #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: #ff329c; } /* Operator */
-  .highlight .p { color: #f8f8f2; } /* Punctuation */
-  .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: #ff329c; } /* Keyword.Namespace */
-  .highlight .kp { color: #66d9ef; } /* Keyword.Pseudo */
-  .highlight .kr { color: #66d9ef; } /* Keyword.Reserved */
-  .highlight .kt { color: #66d9ef; } /* Keyword.Type */
-  .highlight .ld { color: #e6db74; } /* Literal.Date */
-  .highlight .m { color: #ae81ff; } /* Literal.Number */
-  .highlight .s { color: #e6db74; } /* Literal.String */
-  .highlight .na { color: #a6e22e; } /* Name.Attribute */
-  .highlight .nb { color: #f8f8f2; } /* Name.Builtin */
-  .highlight .nc { color: #a6e22e; } /* Name.Class */
-  .highlight .no { color: #66d9ef; } /* Name.Constant */
-  .highlight .nd { color: #a6e22e; } /* Name.Decorator */
-  .highlight .ni { color: #f8f8f2; } /* Name.Entity */
-  .highlight .ne { color: #a6e22e; } /* Name.Exception */
-  .highlight .nf { color: #a6e22e; } /* Name.Function */
-  .highlight .nl { color: #f8f8f2; } /* Name.Label */
-  .highlight .nn { color: #f8f8f2; } /* Name.Namespace */
-  .highlight .nx { color: #a6e22e; } /* Name.Other */
-  .highlight .py { color: #f8f8f2; } /* Name.Property */
-  .highlight .nt { color: #ff329c; } /* Name.Tag */
-  .highlight .nv { color: #f8f8f2; } /* Name.Variable */
-  .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 */
-  .highlight .mi { color: #ae81ff; } /* Literal.Number.Integer */
-  .highlight .mo { color: #ae81ff; } /* Literal.Number.Oct */
-  .highlight .sb { color: #e6db74; } /* Literal.String.Backtick */
-  .highlight .sc { color: #e6db74; } /* Literal.String.Char */
-  .highlight .sd { color: #e6db74; } /* Literal.String.Doc */
-  .highlight .s2 { color: #e6db74; } /* Literal.String.Double */
-  .highlight .se { color: #ae81ff; } /* Literal.String.Escape */
-  .highlight .sh { color: #e6db74; } /* Literal.String.Heredoc */
-  .highlight .si { color: #e6db74; } /* Literal.String.Interpol */
-  .highlight .sx { color: #e6db74; } /* Literal.String.Other */
-  .highlight .sr { color: #e6db74; } /* Literal.String.Regex */
-  .highlight .s1 { color: #e6db74; } /* Literal.String.Single */
-  .highlight .ss { color: #e6db74; } /* Literal.String.Symbol */
-  .highlight .bp { color: #f8f8f2; } /* Name.Builtin.Pseudo */
-  .highlight .vc { color: #f8f8f2; } /* Name.Variable.Class */
-  .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: #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 */
-}

_sass/colors/light-syntax.scss

@@ -1,84 +0,0 @@
-/*
- * The syntax light mode code snippet colors.
- */
-
-@mixin light-syntax {
-  /* based on: <https://raw.githubusercontent.com/jwarby/pygments-css/master/github.css> */
-  .highlight .hll { background-color: #ffffcc; }
-  .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: #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: #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 */
-  .highlight .gt { color: #aa0000; } /* Generic.Traceback */
-  .highlight .kc { color: #000000; font-weight: bold; } /* Keyword.Constant */
-  .highlight .kd { color: #000000; font-weight: bold; } /* Keyword.Declaration */
-  .highlight .kn { color: #000000; font-weight: bold; } /* Keyword.Namespace */
-  .highlight .kp { color: #000000; font-weight: bold; } /* Keyword.Pseudo */
-  .highlight .kr { color: #000000; font-weight: bold; } /* Keyword.Reserved */
-  .highlight .kt { color: #445588; font-weight: bold; } /* Keyword.Type */
-  .highlight .m { color: #009999; } /* Literal.Number */
-  .highlight .s { color: #d01040; } /* Literal.String */
-  .highlight .na { color: #005e5e; } /* Name.Attribute */
-  .highlight .nb { color: #0078a1; } /* Name.Builtin */
-  .highlight .nc { color: #445588; font-weight: bold; } /* Name.Class */
-  .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 */
-  .highlight .nf { color: #990000; font-weight: bold; } /* Name.Function */
-  .highlight .nl { color: #990000; font-weight: bold; } /* Name.Label */
-  .highlight .nn { color: #555555; } /* Name.Namespace */
-  .highlight .nt { color: #000080; } /* Name.Tag */
-  .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 */
-  .highlight .mh { color: #009999; } /* Literal.Number.Hex */
-  .highlight .mi { color: #009999; } /* Literal.Number.Integer */
-  .highlight .mo { color: #009999; } /* Literal.Number.Oct */
-  .highlight .sb { color: #d01040; } /* Literal.String.Backtick */
-  .highlight .sc { color: #d01040; } /* Literal.String.Char */
-  .highlight .sd { color: #d01040; } /* Literal.String.Doc */
-  .highlight .s2 { color: #d01040; } /* Literal.String.Double */
-  .highlight .se { color: #d01040; } /* Literal.String.Escape */
-  .highlight .sh { color: #d01040; } /* Literal.String.Heredoc */
-  .highlight .si { color: #d01040; } /* Literal.String.Interpol */
-  .highlight .sx { color: #d01040; } /* Literal.String.Other */
-  .highlight .sr { color: #009926; } /* Literal.String.Regex */
-  .highlight .s1 { color: #d01040; } /* Literal.String.Single */
-  .highlight .ss { color: #990073; } /* Literal.String.Symbol */
-  .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: #fcfcfc;
-  --highlighter-rouge-color: #3f596f;
-  --highlight-lineno-color: #959595;
-  --inline-code-bg: #f6f6f7;
-  --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;
-  }
-} /* light-syntax */

_sass/colors/syntax-dark.scss

@@ -0,0 +1,138 @@
+/*
+ * The syntax dark mode styles.
+ */
+
+@mixin dark-syntax {
+  --language-border-color: #2d2d2d;
+  --highlight-bg-color: #151515;
+  --highlighter-rouge-color: #ff6e4e;
+  --highlight-lineno-color: #808080;
+  --inline-code-bg: #272822;
+  --code-color: #b0b0b0;
+  --code-header-text-color: #6a6a6a;
+  --code-header-muted-color: #353535;
+  --code-header-icon-color: #565656;
+  --clipboard-checked-color: #2bcc2b;
+  --filepath-text-color: #cacaca;
+
+  .highlight .gp {
+    color: #87939d;
+  }
+
+  /* --- Syntax highlight theme from `rougify style base16.dark` --- */
+
+  .highlight table td {
+    padding: 5px;
+  }
+  .highlight table pre {
+    margin: 0;
+  }
+  .highlight,
+  .highlight .w {
+    color: #d0d0d0;
+    background-color: #151515;
+  }
+  .highlight .err {
+    color: #151515;
+    background-color: #ac4142;
+  }
+  .highlight .c,
+  .highlight .ch,
+  .highlight .cd,
+  .highlight .cm,
+  .highlight .cpf,
+  .highlight .c1,
+  .highlight .cs {
+    color: #848484;
+  }
+  .highlight .cp {
+    color: #f4bf75;
+  }
+  .highlight .nt {
+    color: #f4bf75;
+  }
+  .highlight .o,
+  .highlight .ow {
+    color: #d0d0d0;
+  }
+  .highlight .p,
+  .highlight .pi {
+    color: #d0d0d0;
+  }
+  .highlight .gi {
+    color: #90a959;
+  }
+  .highlight .gd {
+    color: #f08a8b;
+    background-color: #320000;
+  }
+  .highlight .gh {
+    color: #6a9fb5;
+    background-color: #151515;
+    font-weight: bold;
+  }
+  .highlight .k,
+  .highlight .kn,
+  .highlight .kp,
+  .highlight .kr,
+  .highlight .kv {
+    color: #aa759f;
+  }
+  .highlight .kc {
+    color: #d28445;
+  }
+  .highlight .kt {
+    color: #d28445;
+  }
+  .highlight .kd {
+    color: #d28445;
+  }
+  .highlight .s,
+  .highlight .sb,
+  .highlight .sc,
+  .highlight .dl,
+  .highlight .sd,
+  .highlight .s2,
+  .highlight .sh,
+  .highlight .sx,
+  .highlight .s1 {
+    color: #90a959;
+  }
+  .highlight .sa {
+    color: #aa759f;
+  }
+  .highlight .sr {
+    color: #75b5aa;
+  }
+  .highlight .si {
+    color: #b76d45;
+  }
+  .highlight .se {
+    color: #b76d45;
+  }
+  .highlight .nn {
+    color: #f4bf75;
+  }
+  .highlight .nc {
+    color: #f4bf75;
+  }
+  .highlight .no {
+    color: #f4bf75;
+  }
+  .highlight .na {
+    color: #6a9fb5;
+  }
+  .highlight .m,
+  .highlight .mb,
+  .highlight .mf,
+  .highlight .mh,
+  .highlight .mi,
+  .highlight .il,
+  .highlight .mo,
+  .highlight .mx {
+    color: #90a959;
+  }
+  .highlight .ss {
+    color: #90a959;
+  }
+}

_sass/colors/syntax-light.scss

@@ -0,0 +1,179 @@
+/*
+ * The syntax light mode code snippet colors.
+ */
+
+@mixin light-syntax {
+  /* --- custom light colors --- */
+  --language-border-color: #ececec;
+  --highlight-bg-color: #f6f8fa;
+  --highlighter-rouge-color: #3f596f;
+  --highlight-lineno-color: #9e9e9e;
+  --inline-code-bg: #f6f6f7;
+  --code-color: #3a3a3a;
+  --code-header-text-color: #a3a3a3;
+  --code-header-muted-color: #e5e5e5;
+  --code-header-icon-color: #c9c8c8;
+  --clipboard-checked-color: #43c743;
+
+  [class^='prompt-'] {
+    --inline-code-bg: #fbfafa;
+  }
+
+  /* --- Syntax highlight theme from `rougify style github` --- */
+
+  .highlight table td {
+    padding: 5px;
+  }
+  .highlight table pre {
+    margin: 0;
+  }
+  .highlight,
+  .highlight .w {
+    color: #24292f;
+    background-color: #f6f8fa;
+  }
+  .highlight .k,
+  .highlight .kd,
+  .highlight .kn,
+  .highlight .kp,
+  .highlight .kr,
+  .highlight .kt,
+  .highlight .kv {
+    color: #cf222e;
+  }
+  .highlight .gr {
+    color: #f6f8fa;
+  }
+  .highlight .gd {
+    color: #82071e;
+    background-color: #ffebe9;
+  }
+  .highlight .nb {
+    color: #953800;
+  }
+  .highlight .nc {
+    color: #953800;
+  }
+  .highlight .no {
+    color: #953800;
+  }
+  .highlight .nn {
+    color: #953800;
+  }
+  .highlight .sr {
+    color: #116329;
+  }
+  .highlight .na {
+    color: #116329;
+  }
+  .highlight .nt {
+    color: #116329;
+  }
+  .highlight .gi {
+    color: #116329;
+    background-color: #dafbe1;
+  }
+  .highlight .kc {
+    color: #0550ae;
+  }
+  .highlight .l,
+  .highlight .ld,
+  .highlight .m,
+  .highlight .mb,
+  .highlight .mf,
+  .highlight .mh,
+  .highlight .mi,
+  .highlight .il,
+  .highlight .mo,
+  .highlight .mx {
+    color: #0550ae;
+  }
+  .highlight .sb {
+    color: #0550ae;
+  }
+  .highlight .bp {
+    color: #0550ae;
+  }
+  .highlight .ne {
+    color: #0550ae;
+  }
+  .highlight .nl {
+    color: #0550ae;
+  }
+  .highlight .py {
+    color: #0550ae;
+  }
+  .highlight .nv,
+  .highlight .vc,
+  .highlight .vg,
+  .highlight .vi,
+  .highlight .vm {
+    color: #0550ae;
+  }
+  .highlight .o,
+  .highlight .ow {
+    color: #0550ae;
+  }
+  .highlight .gh {
+    color: #0550ae;
+    font-weight: bold;
+  }
+  .highlight .gu {
+    color: #0550ae;
+    font-weight: bold;
+  }
+  .highlight .s,
+  .highlight .sa,
+  .highlight .sc,
+  .highlight .dl,
+  .highlight .sd,
+  .highlight .s2,
+  .highlight .se,
+  .highlight .sh,
+  .highlight .sx,
+  .highlight .s1,
+  .highlight .ss {
+    color: #0a3069;
+  }
+  .highlight .nd {
+    color: #8250df;
+  }
+  .highlight .nf,
+  .highlight .fm {
+    color: #8250df;
+  }
+  .highlight .err {
+    color: #f6f8fa;
+    background-color: #82071e;
+  }
+  .highlight .c,
+  .highlight .ch,
+  .highlight .cd,
+  .highlight .cm,
+  .highlight .cp,
+  .highlight .cpf,
+  .highlight .c1,
+  .highlight .cs {
+    color: #68717a;
+  }
+  .highlight .gl {
+    color: #68717a;
+  }
+  .highlight .gt {
+    color: #68717a;
+  }
+  .highlight .ni {
+    color: #24292f;
+  }
+  .highlight .si {
+    color: #24292f;
+  }
+  .highlight .ge {
+    color: #24292f;
+    font-style: italic;
+  }
+  .highlight .gs {
+    color: #24292f;
+    font-weight: bold;
+  }
+} /* light-syntax */