Adopt four upstream improvements, fixing defects in them

1. meta description (upstream issue Track3#119 — issue only, no PR)
   The theme never emitted <meta name="description">, so params.description
   went unused and Lighthouse reported "document does not have a meta
   description". baseof.html now falls back .Description -> .Summary ->
   .Site.Params.description.

2. Analytics into head (upstream PR Track3#151)
   Loads earlier, losing fewer hits from visitors who leave quickly.

3. code-copy with table layout (upstream PR Track3#137)
   With markup.highlight.lineNos enabled chroma emits a <table> and copying
   grabs the line numbers too; select only the code cell in that case.

4. Admonition shortcodes (upstream PR Track3#130)
   Adds note / tip / warning. Four defects in the original PR are fixed:
   - all three shared one blue border colour, making them indistinguishable
     -> coloured per semantic
   - content background used $highlight-grey, ~2.5:1 against $text, below
     the WCAG AA 4.5:1 minimum -> $light-grey, ~6.5:1
   - vertical margins sat on .admonition-content so the left border did not
     enclose the content -> moved to the container
   - .Inner abutted the <div>, so CommonMark's HTML block rule skipped
     inline Markdown parsing and bold/links inside the box stayed literal
     -> separated by blank lines
   Also drops $_hugo_config, deprecated since Hugo 0.55.

Verified on Hugo v0.164.0+extended: builds with no warnings, all three
colours compile, and Markdown inside the boxes renders.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: xuekepei

assets/js/code-copy.js

@@ -36,7 +36,15 @@
     var codeEl = containerEl.firstElementChild;
     copyBtn.addEventListener('click', function() {
       try {
-        var selection = selectText(codeEl);
+        // 开启 markup.highlight.lineNos 时 chroma 输出 <table>，行号与代码分列两个
+        // 单元格，直接全选会把行号一起复制。此时只选取代码所在的最后一个单元格。
+        // 上游 PR #137
+        var selection;
+        if (codeEl.firstElementChild instanceof HTMLTableElement) {
+          selection = selectText(codeEl.firstElementChild.firstElementChild.firstElementChild.lastElementChild);
+        } else {
+          selection = selectText(codeEl);
+        }
         document.execCommand('copy');
         selection.removeAllRanges();
 

assets/scss/_admonition.scss

@@ -0,0 +1,51 @@
+/* Admonition（note / tip / warning 提示框）
+ *
+ * 基于上游 PR #130，修正三处问题：
+ *   1. 原实现三种类型共用一个边框色，改为按语义分色
+ *   2. 原内容底色用 $highlight-grey (#7d828a)，与 $text (#e8eef2) 对比度约
+ *      2.5:1，低于 WCAG AA 的 4.5:1；改用 $light-grey (#494f5c)，约 6.5:1
+ *   3. 原将上下外边距加在 .admonition-content 上，导致左边框无法包住内容；
+ *      改为加在容器上
+ */
+
+.admonition-highlight {
+  position: relative;
+  display: block;
+  margin: 1.6em 0;
+  border-left: 35px solid;
+
+  &.admonition-note {
+    border-left-color: $admonition-note;
+  }
+
+  &.admonition-tip {
+    border-left-color: $admonition-tip;
+  }
+
+  &.admonition-warning {
+    border-left-color: $admonition-warning;
+  }
+}
+
+.admonition-icon {
+  position: absolute;
+  top: 10px;
+  left: -27px;
+  width: 20px;
+  fill: $text;
+}
+
+.admonition-content {
+  padding: 0.125em 1em;
+  overflow-x: auto;
+  background-color: $light-grey;
+
+  // .Inner 渲染出的首尾段落自带 margin，收一收避免上下留白过大
+  > :first-child {
+    margin-top: 0.75em;
+  }
+
+  > :last-child {
+    margin-bottom: 0.75em;
+  }
+}

assets/scss/_predefined.scss

@@ -7,6 +7,12 @@ $dark-grey: #3B3E48;
 $highlight-grey: #7d828a;
 $midnightblue: #2c3e50;
 
+// Admonition 左边框配色。上游 PR #130 让 note / tip / warning 共用同一个蓝色，
+// 三者视觉上无法区分，这里改为按语义分色。
+$admonition-note: #0594cb;
+$admonition-tip: $theme;
+$admonition-warning: #d9822b;
+
 // Fonts
 //
 $fonts: "Trebuchet MS", Verdana, "Verdana Ref", "Segoe UI", Candara, "Lucida Grande", "Lucida Sans Unicode", "Lucida Sans", Tahoma, sans-serif;

assets/scss/style.scss

@@ -2,6 +2,7 @@
 @import "normalize.scss";
 @import "syntax.scss";
 @import "animate.scss";
+@import "admonition.scss";
 
 /* Webkit Scrollbar Customize */
 ::-webkit-scrollbar {

layouts/_default/baseof.html

@@ -5,6 +5,12 @@
 	<meta charset="UTF-8">
 	<meta name="viewport" content="width=device-width, initial-scale=1.0">
 	<meta http-equiv="X-UA-Compatible" content="ie=edge">
+	{{- /* 统计脚本置于 head 顶部，尽早加载以减少访客快速离开时的漏统计（上游 PR #151） */}}
+	{{- partial "analytics.html" . }}
+	{{- /* 标准 meta description：文章取自身摘要，其余页面回退到 site 的 description（上游 issue #119） */}}
+	{{- with or .Description .Summary .Site.Params.description }}
+	<meta name="description" content="{{ . | plainify | chomp | truncate 150 }}">
+	{{- end }}
 	{{- with .Site.Params.themeColor }}
 	<meta name="theme-color" content="{{.}}">
 	<meta name="msapplication-TileColor" content="{{.}}">
@@ -41,7 +47,6 @@
 		<script src="{{ $script.Permalink }}" {{ printf "integrity=%q" $script.Data.Integrity | safeHTMLAttr }} crossorigin="anonymous"></script>
 	{{ end }}
 
-	{{- partial "analytics.html" . }}
 	{{- if templates.Exists "partials/extra-foot.html" -}}
 	{{ partial "extra-foot.html" . }}
 	{{- end }}

layouts/partials/svg/exclamation.svg

@@ -0,0 +1,12 @@
+{{- /* 请以百分号形式调用（note ... /note），使内部内容按 Markdown 渲染。
+       .Inner 前后必须留空行且不可缩进：紧贴 HTML 标签时 goldmark 会按
+       CommonMark 的 HTML block 规则跳过行内 Markdown 解析，缩进四格则会被
+       当成代码块。上游 PR #130 缺少这两个空行，note 内的加粗与链接不生效。 */ -}}
+<aside class="admonition-highlight admonition-note">
+	<div class="admonition-icon">{{ partial "svg/sticky-note.svg" }}</div>
+	<div class="admonition-content">
+
+{{ .Inner }}
+
+</div>
+</aside>

layouts/partials/svg/lightbulb.svg

@@ -0,0 +1,10 @@
+{{- /* 请以百分号形式调用（tip ... /tip）。.Inner 前后的空行不可省略，
+       原因见 note.html 的说明。 */ -}}
+<aside class="admonition-highlight admonition-tip">
+	<div class="admonition-icon">{{ partial "svg/lightbulb.svg" }}</div>
+	<div class="admonition-content">
+
+{{ .Inner }}
+
+</div>
+</aside>