Make callout headings explicit

CONTENT_BRIDGE.md

@@ -94,7 +94,9 @@ forward, use normal Markdown and let Astro CSS handle presentation.
 
 ### Callouts
 
-Write callouts as portable blockquotes. This is the canonical form:
+Write callouts as portable blockquotes. The type controls the visual styling,
+but it does not create a visible heading by itself. This is the canonical form
+for a titleless note:
 
 ```markdown
 > **Note**
@@ -110,13 +112,31 @@ Supported labels are `Note`, `Tip`, `Warning`, `Caution`, and `Aside`:
 > This point needs attention.
 ```
 
-Obsidian-style labels also work:
+Obsidian-style bracket labels also work. A plain bracket label is still
+titleless:
 
 ```markdown
 > [!tip]
 > This is a tip.
 ```
 
+To show a heading, put it explicitly inside the bracket after `:` or `|`:
+
+```markdown
+> [!tip: Useful observation]
+>
+> Text of the callout.
+
+> [!warning|Check this assumption]
+>
+> This point needs attention.
+```
+
+The text after `:` or `|` is treated as the only callout heading. Do not write
+`> [!tip] Useful observation` for a heading; that form is interpreted as a
+titleless tip whose body begins with “Useful observation”. This keeps the
+Markdown unambiguous across Astro, Pandoc, and LaTeX.
+
 For quick writing, a few leading emoji markers are recognized and stripped:
 
 ```markdown
@@ -139,9 +159,9 @@ aside   -> blogasidebox
 
 The LaTeX boxes use `tcolorbox` with the `breakable` and `enhanced` libraries,
 a light tinted background, a thin frame, a stronger left rule, and a small
-attached title label. This follows the same design vocabulary as the DM book
-callouts: compact colored boxes that can split across pages without becoming
-visually heavy.
+attached title only when the Markdown explicitly provides one. This follows the
+same design vocabulary as the DM book callouts: compact colored boxes that can
+split across pages without becoming visually heavy.
 
 Quarto margin notes such as `[text]{.aside}` were converted to:
 

scripts/import-quarto-blog.mjs

@@ -279,7 +279,8 @@ authorName: "Neeldhara"
 - Standard Markdown headings, lists, links, tables, code fences, footnotes, and raw HTML are preserved.
 - Use colocated relative assets: \`![Caption](image.png)\`.
 - Quarto image attributes such as \`{width=70%}\` are removed during import. Use normal Markdown now; layout should be handled by Astro CSS.
-- Quarto callouts are converted to simple blockquotes:
+- Quarto callouts are converted to simple blockquotes. The callout type controls
+  styling only; it does not create a visible heading by default:
 
 \`\`\`markdown
 > **Note**
@@ -287,14 +288,22 @@ authorName: "Neeldhara"
 > Text of the callout.
 \`\`\`
 
-- For new notes, use the same blockquote convention for portable callouts:
+- For new notes, the bracket form is also supported:
 
 \`\`\`markdown
-> **Warning**
+> [!warning]
 >
 > This point needs attention.
 \`\`\`
 
+- To show a heading, put it explicitly inside the bracket after \`:\` or \`|\`:
+
+\`\`\`markdown
+> [!tip: Useful observation]
+>
+> Text of the callout.
+\`\`\`
+
 - Quarto margin notes such as \`[text]{.aside}\` are converted to:
 
 \`\`\`markdown

scripts/pandoc-filters/semantic-blocks.lua

@@ -101,6 +101,13 @@ local function first_inline_text(block)
   return inline_text(block.content[1])
 end
 
+local function paragraph_text(block)
+  if not block or block.t ~= "Para" then
+    return ""
+  end
+  return pandoc.utils.stringify(block)
+end
+
 local function latex_escape(value)
   value = tostring(value or "")
   value = value:gsub("\\", "\\textbackslash{}")
@@ -356,6 +363,70 @@ local function strip_text_prefix(block, pattern)
   end
 end
 
+local function cleanup_inline_start(block)
+  if not block or block.t ~= "Para" or not block.content then
+    return
+  end
+
+  while #block.content > 0 do
+    local first = block.content[1]
+    if first.t == "Space" or first.t == "SoftBreak" or first.t == "LineBreak" then
+      table.remove(block.content, 1)
+    elseif first.t == "Str" then
+      first.text = first.text:gsub("^%s+", "")
+      if first.text == "" then
+        table.remove(block.content, 1)
+      else
+        return
+      end
+    else
+      return
+    end
+  end
+end
+
+local function strip_bracket_callout(block)
+  if not block or block.t ~= "Para" or not block.content then
+    return
+  end
+
+  while #block.content > 0 do
+    local first = block.content[1]
+    local text = inline_text(first)
+    local close_index = text:find("%]")
+
+    if close_index then
+      local remaining = text:sub(close_index + 1):gsub("^%s+", "")
+      if first.t == "Str" and remaining ~= "" then
+        first.text = remaining
+      elseif remaining ~= "" then
+        block.content[1] = pandoc.Str(remaining)
+      else
+        table.remove(block.content, 1)
+      end
+      break
+    end
+
+    table.remove(block.content, 1)
+  end
+
+  cleanup_inline_start(block)
+end
+
+local function parse_bracket_callout(text)
+  local key, title = text:match("^%s*%[!([%a-]+)%s*[:|]%s*([^%]]+)%]")
+  if key then
+    return normalize_label(key), title:gsub("^%s+", ""):gsub("%s+$", "")
+  end
+
+  key = text:match("^%s*%[!([%a-]+)%]")
+  if key then
+    return normalize_label(key), ""
+  end
+
+  return nil, nil
+end
+
 local function detect_callout(block)
   local text = first_inline_text(block)
   if text == "" then
@@ -365,21 +436,18 @@ local function detect_callout(block)
   if block.content[1].t == "Strong" then
     local key = normalize_label(text)
     if callout_labels[key] then
-      return { key = key, label = callout_labels[key], remover = "strong" }
+      return { key = key, title = "", remover = "strong" }
     end
   end
 
-  local bracket = text:match("^%[!([%a-]+)%]")
-  if bracket then
-    local key = normalize_label(bracket)
-    if callout_labels[key] then
-      return { key = key, label = callout_labels[key], remover = "bracket" }
-    end
+  local key, title = parse_bracket_callout(paragraph_text(block))
+  if key and callout_labels[key] then
+    return { key = key, title = title or "", remover = "bracket" }
   end
 
   for _, item in ipairs(callout_markers) do
     if text:sub(1, #item.marker) == item.marker then
-      return { key = item.key, label = callout_labels[item.key], remover = "marker", marker = item.marker }
+      return { key = item.key, title = "", remover = "marker", marker = item.marker }
     end
   end
 
@@ -400,7 +468,7 @@ local function callout_to_latex(el)
   if callout.remover == "strong" then
     remove_first_inline(blocks[1])
   elseif callout.remover == "bracket" then
-    strip_text_prefix(blocks[1], "^%[![%a-]+%]%s*")
+    strip_bracket_callout(blocks[1])
   elseif callout.remover == "marker" then
     strip_text_prefix(blocks[1], "^" .. callout.marker .. "%s*")
   end
@@ -412,7 +480,7 @@ local function callout_to_latex(el)
   local env = callout_envs[callout.key] or "blognotebox"
   return pandoc.RawBlock(
     "latex",
-    "\\begin{" .. env .. "}{}\n"
+    "\\begin{" .. env .. "}{" .. latex_escape(callout.title or "") .. "}\n"
       .. blocks_to_latex(blocks)
       .. "\n\\end{" .. env .. "}"
   )

scripts/pandoc-templates/semantic-preamble.tex

@@ -46,49 +46,119 @@
   }
 }
 
-\newtcolorbox{blognotebox}[2][]{
+\NewDocumentEnvironment{blognotebox}{O{} m}{%
+  \if\relax\detokenize{#2}\relax
+    \begin{tcolorbox}[
       blog callout,
-  title={NOTE\if\relax\detokenize{#2}\relax\else: #2\fi},
       colback=BlogCalloutNoteBack,
       colframe=BlogCalloutNoteFrame,
       boxed title style={colback=BlogCalloutNoteBack},
       #1
+    ]%
+  \else
+    \begin{tcolorbox}[
+      blog callout,
+      title={#2},
+      colback=BlogCalloutNoteBack,
+      colframe=BlogCalloutNoteFrame,
+      boxed title style={colback=BlogCalloutNoteBack},
+      #1
+    ]%
+  \fi
+}{%
+  \end{tcolorbox}%
 }
 
-\newtcolorbox{blogtipbox}[2][]{
+\NewDocumentEnvironment{blogtipbox}{O{} m}{%
+  \if\relax\detokenize{#2}\relax
+    \begin{tcolorbox}[
       blog callout,
-  title={TIP\if\relax\detokenize{#2}\relax\else: #2\fi},
       colback=BlogCalloutTipBack,
       colframe=BlogCalloutTipFrame,
       boxed title style={colback=BlogCalloutTipBack},
       #1
+    ]%
+  \else
+    \begin{tcolorbox}[
+      blog callout,
+      title={#2},
+      colback=BlogCalloutTipBack,
+      colframe=BlogCalloutTipFrame,
+      boxed title style={colback=BlogCalloutTipBack},
+      #1
+    ]%
+  \fi
+}{%
+  \end{tcolorbox}%
 }
 
-\newtcolorbox{blogwarningbox}[2][]{
+\NewDocumentEnvironment{blogwarningbox}{O{} m}{%
+  \if\relax\detokenize{#2}\relax
+    \begin{tcolorbox}[
       blog callout,
-  title={WARNING\if\relax\detokenize{#2}\relax\else: #2\fi},
       colback=BlogCalloutWarningBack,
       colframe=BlogCalloutWarningFrame,
       boxed title style={colback=BlogCalloutWarningBack},
       #1
+    ]%
+  \else
+    \begin{tcolorbox}[
+      blog callout,
+      title={#2},
+      colback=BlogCalloutWarningBack,
+      colframe=BlogCalloutWarningFrame,
+      boxed title style={colback=BlogCalloutWarningBack},
+      #1
+    ]%
+  \fi
+}{%
+  \end{tcolorbox}%
 }
 
-\newtcolorbox{blogcautionbox}[2][]{
+\NewDocumentEnvironment{blogcautionbox}{O{} m}{%
+  \if\relax\detokenize{#2}\relax
+    \begin{tcolorbox}[
       blog callout,
-  title={CAUTION\if\relax\detokenize{#2}\relax\else: #2\fi},
       colback=BlogCalloutCautionBack,
       colframe=BlogCalloutCautionFrame,
       boxed title style={colback=BlogCalloutCautionBack},
       #1
+    ]%
+  \else
+    \begin{tcolorbox}[
+      blog callout,
+      title={#2},
+      colback=BlogCalloutCautionBack,
+      colframe=BlogCalloutCautionFrame,
+      boxed title style={colback=BlogCalloutCautionBack},
+      #1
+    ]%
+  \fi
+}{%
+  \end{tcolorbox}%
 }
 
-\newtcolorbox{blogasidebox}[2][]{
+\NewDocumentEnvironment{blogasidebox}{O{} m}{%
+  \if\relax\detokenize{#2}\relax
+    \begin{tcolorbox}[
       blog callout,
-  title={ASIDE\if\relax\detokenize{#2}\relax\else: #2\fi},
       colback=BlogCalloutAsideBack,
       colframe=BlogCalloutAsideFrame,
       boxed title style={colback=BlogCalloutAsideBack},
       #1
+    ]%
+  \else
+    \begin{tcolorbox}[
+      blog callout,
+      title={#2},
+      colback=BlogCalloutAsideBack,
+      colframe=BlogCalloutAsideFrame,
+      boxed title style={colback=BlogCalloutAsideBack},
+      #1
+    ]%
+  \fi
+}{%
+  \end{tcolorbox}%
 }
 
 \ExplSyntaxOn

sites/art/src/remark/callouts.mjs

@@ -1,19 +1,21 @@
-const CALLOUT_LABELS = new Map([
-  ["aside", "Aside"],
-  ["caution", "Caution"],
-  ["note", "Note"],
-  ["tip", "Tip"],
-  ["warning", "Warning"],
+const CALLOUT_TYPES = new Set([
+  "aside",
+  "caution",
+  "note",
+  "tip",
+  "warning",
 ]);
 
 const CALLOUT_MARKERS = new Map([
-  ["📝", "Note"],
-  ["💡", "Tip"],
-  ["⚡", "Tip"],
-  ["⚠️", "Warning"],
-  ["⚠", "Warning"],
+  ["📝", "note"],
+  ["💡", "tip"],
+  ["⚡", "tip"],
+  ["⚠️", "warning"],
+  ["⚠", "warning"],
 ]);
 
+const BRACKET_CALLOUT_PATTERN = /^\s*\[!(aside|caution|note|tip|warning)(?::\s*([^\]\r\n]+)|\|\s*([^\]\r\n]+))?\]\s*/i;
+
 function textFromInline(node) {
   if (!node) return "";
   if (typeof node.value === "string") return node.value;
@@ -21,7 +23,7 @@ function textFromInline(node) {
   return node.children.map(textFromInline).join("");
 }
 
-function normalizeLabel(value) {
+function normalizeType(value) {
   return value
     .trim()
     .replace(/^["“”]+|["“”]+$/g, "")
@@ -29,48 +31,99 @@ function normalizeLabel(value) {
     .toLowerCase();
 }
 
-function paragraphCalloutLabel(paragraph) {
+function calloutType(value) {
+  const type = normalizeType(value);
+  return CALLOUT_TYPES.has(type) ? type : null;
+}
+
+function parseBracketCallout(value) {
+  const match = value.match(BRACKET_CALLOUT_PATTERN);
+  if (!match) return null;
+
+  return {
+    kind: "bracket",
+    type: calloutType(match[1]),
+    title: (match[2] ?? match[3] ?? "").trim(),
+  };
+}
+
+function paragraphCallout(paragraph) {
   if (paragraph?.type !== "paragraph") return null;
 
   const first = paragraph.children?.[0];
   if (first?.type === "text") {
-    const match = first.value.match(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i);
-    if (match) {
-      return CALLOUT_LABELS.get(normalizeLabel(match[1]));
+    const bracket = parseBracketCallout(first.value);
+    if (bracket?.type) {
+      return bracket;
     }
 
     const trimmed = first.value.trimStart();
-    for (const [marker, label] of CALLOUT_MARKERS) {
+    for (const [marker, type] of CALLOUT_MARKERS) {
       if (trimmed.startsWith(marker)) {
-        return label;
+        return { kind: "marker", type, title: "", marker };
       }
     }
   }
 
   if (first?.type !== "strong") return null;
 
-  const label = CALLOUT_LABELS.get(normalizeLabel(textFromInline(first)));
-  if (!label) return null;
+  const type = calloutType(textFromInline(first));
+  if (!type) return null;
 
-  return label;
+  return { kind: "strong", type, title: "" };
 }
 
-function removeLeadingLabel(paragraph, label) {
+function cleanupParagraphStart(paragraph) {
+  while (paragraph.children?.length > 0) {
+    const first = paragraph.children[0];
+    if (first.type === "text") {
+      first.value = first.value.replace(/^\s+/, "");
+      if (first.value) return;
+      paragraph.children.shift();
+      continue;
+    }
+
+    if (first.type === "break") {
+      paragraph.children.shift();
+      continue;
+    }
+
+    return;
+  }
+}
+
+function calloutTitleParagraph(title) {
+  return {
+    type: "paragraph",
+    data: {
+      hName: "p",
+      hProperties: {
+        className: ["callout-title"],
+      },
+    },
+    children: [{ type: "text", value: title }],
+  };
+}
+
+function removeLeadingCallout(paragraph, callout) {
   if (paragraph?.type !== "paragraph") return;
 
   const first = paragraph.children?.[0];
-  if (first?.type === "text") {
-    first.value = first.value.replace(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i, "");
-    for (const marker of CALLOUT_MARKERS.keys()) {
-      const escapedMarker = marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
-      first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
-    }
-    if (!first.value) paragraph.children.shift();
+  if (callout.kind === "bracket" && first?.type === "text") {
+    first.value = first.value.replace(BRACKET_CALLOUT_PATTERN, "");
+    cleanupParagraphStart(paragraph);
     return;
   }
 
-  const firstText = normalizeLabel(textFromInline(first));
-  if (!first || first.type !== "strong" || firstText !== label.toLowerCase()) {
+  if (callout.kind === "marker" && first?.type === "text") {
+    const escapedMarker = callout.marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+    first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
+    cleanupParagraphStart(paragraph);
+    return;
+  }
+
+  const firstText = calloutType(textFromInline(first));
+  if (callout.kind !== "strong" || !first || first.type !== "strong" || firstText !== callout.type) {
     return;
   }
 
@@ -81,25 +134,30 @@ function removeLeadingLabel(paragraph, label) {
     next.value = next.value.replace(/^:\s*/, "").replace(/^\s+/, "");
     if (!next.value) paragraph.children.shift();
   }
+
+  cleanupParagraphStart(paragraph);
 }
 
 function transformBlockquote(node) {
   if (node.type !== "blockquote") return;
 
   const first = node.children?.[0];
-  const label = paragraphCalloutLabel(first);
-  if (!label) return;
+  const callout = paragraphCallout(first);
+  if (!callout) return;
 
-  removeLeadingLabel(first, label);
+  removeLeadingCallout(first, callout);
   if (first.children?.length === 0) {
     node.children.shift();
   }
 
+  if (callout.title) {
+    node.children.unshift(calloutTitleParagraph(callout.title));
+  }
+
   node.data = {
     hName: "aside",
     hProperties: {
-      className: ["callout", `callout-${label.toLowerCase()}`],
-      dataCalloutLabel: label,
+      className: ["callout", `callout-${callout.type}`],
     },
   };
 }

sites/art/src/styles/article.css

@@ -221,6 +221,15 @@
   margin-top: 0.8rem;
 }
 
+.article-content :where(.callout-title) {
+  margin: 0 0 0.45rem;
+  color: color-mix(in srgb, hsl(var(--primary)) 78%, hsl(var(--foreground)));
+  font-family: var(--font-fraunces);
+  font-size: 1rem;
+  font-weight: 650;
+  line-height: 1.35;
+}
+
 .article-content :where(.callout h1) {
   font-size: 1.35rem;
 }

sites/poetry/src/remark/callouts.mjs

@@ -1,19 +1,21 @@
-const CALLOUT_LABELS = new Map([
-  ["aside", "Aside"],
-  ["caution", "Caution"],
-  ["note", "Note"],
-  ["tip", "Tip"],
-  ["warning", "Warning"],
+const CALLOUT_TYPES = new Set([
+  "aside",
+  "caution",
+  "note",
+  "tip",
+  "warning",
 ]);
 
 const CALLOUT_MARKERS = new Map([
-  ["📝", "Note"],
-  ["💡", "Tip"],
-  ["⚡", "Tip"],
-  ["⚠️", "Warning"],
-  ["⚠", "Warning"],
+  ["📝", "note"],
+  ["💡", "tip"],
+  ["⚡", "tip"],
+  ["⚠️", "warning"],
+  ["⚠", "warning"],
 ]);
 
+const BRACKET_CALLOUT_PATTERN = /^\s*\[!(aside|caution|note|tip|warning)(?::\s*([^\]\r\n]+)|\|\s*([^\]\r\n]+))?\]\s*/i;
+
 function textFromInline(node) {
   if (!node) return "";
   if (typeof node.value === "string") return node.value;
@@ -21,7 +23,7 @@ function textFromInline(node) {
   return node.children.map(textFromInline).join("");
 }
 
-function normalizeLabel(value) {
+function normalizeType(value) {
   return value
     .trim()
     .replace(/^["“”]+|["“”]+$/g, "")
@@ -29,48 +31,99 @@ function normalizeLabel(value) {
     .toLowerCase();
 }
 
-function paragraphCalloutLabel(paragraph) {
+function calloutType(value) {
+  const type = normalizeType(value);
+  return CALLOUT_TYPES.has(type) ? type : null;
+}
+
+function parseBracketCallout(value) {
+  const match = value.match(BRACKET_CALLOUT_PATTERN);
+  if (!match) return null;
+
+  return {
+    kind: "bracket",
+    type: calloutType(match[1]),
+    title: (match[2] ?? match[3] ?? "").trim(),
+  };
+}
+
+function paragraphCallout(paragraph) {
   if (paragraph?.type !== "paragraph") return null;
 
   const first = paragraph.children?.[0];
   if (first?.type === "text") {
-    const match = first.value.match(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i);
-    if (match) {
-      return CALLOUT_LABELS.get(normalizeLabel(match[1]));
+    const bracket = parseBracketCallout(first.value);
+    if (bracket?.type) {
+      return bracket;
     }
 
     const trimmed = first.value.trimStart();
-    for (const [marker, label] of CALLOUT_MARKERS) {
+    for (const [marker, type] of CALLOUT_MARKERS) {
       if (trimmed.startsWith(marker)) {
-        return label;
+        return { kind: "marker", type, title: "", marker };
       }
     }
   }
 
   if (first?.type !== "strong") return null;
 
-  const label = CALLOUT_LABELS.get(normalizeLabel(textFromInline(first)));
-  if (!label) return null;
+  const type = calloutType(textFromInline(first));
+  if (!type) return null;
 
-  return label;
+  return { kind: "strong", type, title: "" };
 }
 
-function removeLeadingLabel(paragraph, label) {
+function cleanupParagraphStart(paragraph) {
+  while (paragraph.children?.length > 0) {
+    const first = paragraph.children[0];
+    if (first.type === "text") {
+      first.value = first.value.replace(/^\s+/, "");
+      if (first.value) return;
+      paragraph.children.shift();
+      continue;
+    }
+
+    if (first.type === "break") {
+      paragraph.children.shift();
+      continue;
+    }
+
+    return;
+  }
+}
+
+function calloutTitleParagraph(title) {
+  return {
+    type: "paragraph",
+    data: {
+      hName: "p",
+      hProperties: {
+        className: ["callout-title"],
+      },
+    },
+    children: [{ type: "text", value: title }],
+  };
+}
+
+function removeLeadingCallout(paragraph, callout) {
   if (paragraph?.type !== "paragraph") return;
 
   const first = paragraph.children?.[0];
-  if (first?.type === "text") {
-    first.value = first.value.replace(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i, "");
-    for (const marker of CALLOUT_MARKERS.keys()) {
-      const escapedMarker = marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
-      first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
-    }
-    if (!first.value) paragraph.children.shift();
+  if (callout.kind === "bracket" && first?.type === "text") {
+    first.value = first.value.replace(BRACKET_CALLOUT_PATTERN, "");
+    cleanupParagraphStart(paragraph);
     return;
   }
 
-  const firstText = normalizeLabel(textFromInline(first));
-  if (!first || first.type !== "strong" || firstText !== label.toLowerCase()) {
+  if (callout.kind === "marker" && first?.type === "text") {
+    const escapedMarker = callout.marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+    first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
+    cleanupParagraphStart(paragraph);
+    return;
+  }
+
+  const firstText = calloutType(textFromInline(first));
+  if (callout.kind !== "strong" || !first || first.type !== "strong" || firstText !== callout.type) {
     return;
   }
 
@@ -81,25 +134,30 @@ function removeLeadingLabel(paragraph, label) {
     next.value = next.value.replace(/^:\s*/, "").replace(/^\s+/, "");
     if (!next.value) paragraph.children.shift();
   }
+
+  cleanupParagraphStart(paragraph);
 }
 
 function transformBlockquote(node) {
   if (node.type !== "blockquote") return;
 
   const first = node.children?.[0];
-  const label = paragraphCalloutLabel(first);
-  if (!label) return;
+  const callout = paragraphCallout(first);
+  if (!callout) return;
 
-  removeLeadingLabel(first, label);
+  removeLeadingCallout(first, callout);
   if (first.children?.length === 0) {
     node.children.shift();
   }
 
+  if (callout.title) {
+    node.children.unshift(calloutTitleParagraph(callout.title));
+  }
+
   node.data = {
     hName: "aside",
     hProperties: {
-      className: ["callout", `callout-${label.toLowerCase()}`],
-      dataCalloutLabel: label,
+      className: ["callout", `callout-${callout.type}`],
     },
   };
 }

sites/poetry/src/styles/article.css

@@ -221,6 +221,15 @@
   margin-top: 0.8rem;
 }
 
+.article-content :where(.callout-title) {
+  margin: 0 0 0.45rem;
+  color: color-mix(in srgb, hsl(var(--primary)) 78%, hsl(var(--foreground)));
+  font-family: var(--font-fraunces);
+  font-size: 1rem;
+  font-weight: 650;
+  line-height: 1.35;
+}
+
 .article-content :where(.callout h1) {
   font-size: 1.35rem;
 }

sites/puzzles/src/remark/callouts.mjs

@@ -1,19 +1,21 @@
-const CALLOUT_LABELS = new Map([
-  ["aside", "Aside"],
-  ["caution", "Caution"],
-  ["note", "Note"],
-  ["tip", "Tip"],
-  ["warning", "Warning"],
+const CALLOUT_TYPES = new Set([
+  "aside",
+  "caution",
+  "note",
+  "tip",
+  "warning",
 ]);
 
 const CALLOUT_MARKERS = new Map([
-  ["📝", "Note"],
-  ["💡", "Tip"],
-  ["⚡", "Tip"],
-  ["⚠️", "Warning"],
-  ["⚠", "Warning"],
+  ["📝", "note"],
+  ["💡", "tip"],
+  ["⚡", "tip"],
+  ["⚠️", "warning"],
+  ["⚠", "warning"],
 ]);
 
+const BRACKET_CALLOUT_PATTERN = /^\s*\[!(aside|caution|note|tip|warning)(?::\s*([^\]\r\n]+)|\|\s*([^\]\r\n]+))?\]\s*/i;
+
 function textFromInline(node) {
   if (!node) return "";
   if (typeof node.value === "string") return node.value;
@@ -21,7 +23,7 @@ function textFromInline(node) {
   return node.children.map(textFromInline).join("");
 }
 
-function normalizeLabel(value) {
+function normalizeType(value) {
   return value
     .trim()
     .replace(/^["“”]+|["“”]+$/g, "")
@@ -29,48 +31,99 @@ function normalizeLabel(value) {
     .toLowerCase();
 }
 
-function paragraphCalloutLabel(paragraph) {
+function calloutType(value) {
+  const type = normalizeType(value);
+  return CALLOUT_TYPES.has(type) ? type : null;
+}
+
+function parseBracketCallout(value) {
+  const match = value.match(BRACKET_CALLOUT_PATTERN);
+  if (!match) return null;
+
+  return {
+    kind: "bracket",
+    type: calloutType(match[1]),
+    title: (match[2] ?? match[3] ?? "").trim(),
+  };
+}
+
+function paragraphCallout(paragraph) {
   if (paragraph?.type !== "paragraph") return null;
 
   const first = paragraph.children?.[0];
   if (first?.type === "text") {
-    const match = first.value.match(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i);
-    if (match) {
-      return CALLOUT_LABELS.get(normalizeLabel(match[1]));
+    const bracket = parseBracketCallout(first.value);
+    if (bracket?.type) {
+      return bracket;
     }
 
     const trimmed = first.value.trimStart();
-    for (const [marker, label] of CALLOUT_MARKERS) {
+    for (const [marker, type] of CALLOUT_MARKERS) {
       if (trimmed.startsWith(marker)) {
-        return label;
+        return { kind: "marker", type, title: "", marker };
       }
     }
   }
 
   if (first?.type !== "strong") return null;
 
-  const label = CALLOUT_LABELS.get(normalizeLabel(textFromInline(first)));
-  if (!label) return null;
+  const type = calloutType(textFromInline(first));
+  if (!type) return null;
 
-  return label;
+  return { kind: "strong", type, title: "" };
 }
 
-function removeLeadingLabel(paragraph, label) {
+function cleanupParagraphStart(paragraph) {
+  while (paragraph.children?.length > 0) {
+    const first = paragraph.children[0];
+    if (first.type === "text") {
+      first.value = first.value.replace(/^\s+/, "");
+      if (first.value) return;
+      paragraph.children.shift();
+      continue;
+    }
+
+    if (first.type === "break") {
+      paragraph.children.shift();
+      continue;
+    }
+
+    return;
+  }
+}
+
+function calloutTitleParagraph(title) {
+  return {
+    type: "paragraph",
+    data: {
+      hName: "p",
+      hProperties: {
+        className: ["callout-title"],
+      },
+    },
+    children: [{ type: "text", value: title }],
+  };
+}
+
+function removeLeadingCallout(paragraph, callout) {
   if (paragraph?.type !== "paragraph") return;
 
   const first = paragraph.children?.[0];
-  if (first?.type === "text") {
-    first.value = first.value.replace(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i, "");
-    for (const marker of CALLOUT_MARKERS.keys()) {
-      const escapedMarker = marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
-      first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
-    }
-    if (!first.value) paragraph.children.shift();
+  if (callout.kind === "bracket" && first?.type === "text") {
+    first.value = first.value.replace(BRACKET_CALLOUT_PATTERN, "");
+    cleanupParagraphStart(paragraph);
     return;
   }
 
-  const firstText = normalizeLabel(textFromInline(first));
-  if (!first || first.type !== "strong" || firstText !== label.toLowerCase()) {
+  if (callout.kind === "marker" && first?.type === "text") {
+    const escapedMarker = callout.marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+    first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
+    cleanupParagraphStart(paragraph);
+    return;
+  }
+
+  const firstText = calloutType(textFromInline(first));
+  if (callout.kind !== "strong" || !first || first.type !== "strong" || firstText !== callout.type) {
     return;
   }
 
@@ -81,25 +134,30 @@ function removeLeadingLabel(paragraph, label) {
     next.value = next.value.replace(/^:\s*/, "").replace(/^\s+/, "");
     if (!next.value) paragraph.children.shift();
   }
+
+  cleanupParagraphStart(paragraph);
 }
 
 function transformBlockquote(node) {
   if (node.type !== "blockquote") return;
 
   const first = node.children?.[0];
-  const label = paragraphCalloutLabel(first);
-  if (!label) return;
+  const callout = paragraphCallout(first);
+  if (!callout) return;
 
-  removeLeadingLabel(first, label);
+  removeLeadingCallout(first, callout);
   if (first.children?.length === 0) {
     node.children.shift();
   }
 
+  if (callout.title) {
+    node.children.unshift(calloutTitleParagraph(callout.title));
+  }
+
   node.data = {
     hName: "aside",
     hProperties: {
-      className: ["callout", `callout-${label.toLowerCase()}`],
-      dataCalloutLabel: label,
+      className: ["callout", `callout-${callout.type}`],
     },
   };
 }

sites/puzzles/src/styles/article.css

@@ -221,6 +221,15 @@
   margin-top: 0.8rem;
 }
 
+.article-content :where(.callout-title) {
+  margin: 0 0 0.45rem;
+  color: color-mix(in srgb, hsl(var(--primary)) 78%, hsl(var(--foreground)));
+  font-family: var(--font-fraunces);
+  font-size: 1rem;
+  font-weight: 650;
+  line-height: 1.35;
+}
+
 .article-content :where(.callout h1) {
   font-size: 1.35rem;
 }

sites/reflections/src/remark/callouts.mjs

@@ -1,19 +1,21 @@
-const CALLOUT_LABELS = new Map([
-  ["aside", "Aside"],
-  ["caution", "Caution"],
-  ["note", "Note"],
-  ["tip", "Tip"],
-  ["warning", "Warning"],
+const CALLOUT_TYPES = new Set([
+  "aside",
+  "caution",
+  "note",
+  "tip",
+  "warning",
 ]);
 
 const CALLOUT_MARKERS = new Map([
-  ["📝", "Note"],
-  ["💡", "Tip"],
-  ["⚡", "Tip"],
-  ["⚠️", "Warning"],
-  ["⚠", "Warning"],
+  ["📝", "note"],
+  ["💡", "tip"],
+  ["⚡", "tip"],
+  ["⚠️", "warning"],
+  ["⚠", "warning"],
 ]);
 
+const BRACKET_CALLOUT_PATTERN = /^\s*\[!(aside|caution|note|tip|warning)(?::\s*([^\]\r\n]+)|\|\s*([^\]\r\n]+))?\]\s*/i;
+
 function textFromInline(node) {
   if (!node) return "";
   if (typeof node.value === "string") return node.value;
@@ -21,7 +23,7 @@ function textFromInline(node) {
   return node.children.map(textFromInline).join("");
 }
 
-function normalizeLabel(value) {
+function normalizeType(value) {
   return value
     .trim()
     .replace(/^["“”]+|["“”]+$/g, "")
@@ -29,48 +31,99 @@ function normalizeLabel(value) {
     .toLowerCase();
 }
 
-function paragraphCalloutLabel(paragraph) {
+function calloutType(value) {
+  const type = normalizeType(value);
+  return CALLOUT_TYPES.has(type) ? type : null;
+}
+
+function parseBracketCallout(value) {
+  const match = value.match(BRACKET_CALLOUT_PATTERN);
+  if (!match) return null;
+
+  return {
+    kind: "bracket",
+    type: calloutType(match[1]),
+    title: (match[2] ?? match[3] ?? "").trim(),
+  };
+}
+
+function paragraphCallout(paragraph) {
   if (paragraph?.type !== "paragraph") return null;
 
   const first = paragraph.children?.[0];
   if (first?.type === "text") {
-    const match = first.value.match(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i);
-    if (match) {
-      return CALLOUT_LABELS.get(normalizeLabel(match[1]));
+    const bracket = parseBracketCallout(first.value);
+    if (bracket?.type) {
+      return bracket;
     }
 
     const trimmed = first.value.trimStart();
-    for (const [marker, label] of CALLOUT_MARKERS) {
+    for (const [marker, type] of CALLOUT_MARKERS) {
       if (trimmed.startsWith(marker)) {
-        return label;
+        return { kind: "marker", type, title: "", marker };
       }
     }
   }
 
   if (first?.type !== "strong") return null;
 
-  const label = CALLOUT_LABELS.get(normalizeLabel(textFromInline(first)));
-  if (!label) return null;
+  const type = calloutType(textFromInline(first));
+  if (!type) return null;
 
-  return label;
+  return { kind: "strong", type, title: "" };
 }
 
-function removeLeadingLabel(paragraph, label) {
+function cleanupParagraphStart(paragraph) {
+  while (paragraph.children?.length > 0) {
+    const first = paragraph.children[0];
+    if (first.type === "text") {
+      first.value = first.value.replace(/^\s+/, "");
+      if (first.value) return;
+      paragraph.children.shift();
+      continue;
+    }
+
+    if (first.type === "break") {
+      paragraph.children.shift();
+      continue;
+    }
+
+    return;
+  }
+}
+
+function calloutTitleParagraph(title) {
+  return {
+    type: "paragraph",
+    data: {
+      hName: "p",
+      hProperties: {
+        className: ["callout-title"],
+      },
+    },
+    children: [{ type: "text", value: title }],
+  };
+}
+
+function removeLeadingCallout(paragraph, callout) {
   if (paragraph?.type !== "paragraph") return;
 
   const first = paragraph.children?.[0];
-  if (first?.type === "text") {
-    first.value = first.value.replace(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i, "");
-    for (const marker of CALLOUT_MARKERS.keys()) {
-      const escapedMarker = marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
-      first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
-    }
-    if (!first.value) paragraph.children.shift();
+  if (callout.kind === "bracket" && first?.type === "text") {
+    first.value = first.value.replace(BRACKET_CALLOUT_PATTERN, "");
+    cleanupParagraphStart(paragraph);
     return;
   }
 
-  const firstText = normalizeLabel(textFromInline(first));
-  if (!first || first.type !== "strong" || firstText !== label.toLowerCase()) {
+  if (callout.kind === "marker" && first?.type === "text") {
+    const escapedMarker = callout.marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+    first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
+    cleanupParagraphStart(paragraph);
+    return;
+  }
+
+  const firstText = calloutType(textFromInline(first));
+  if (callout.kind !== "strong" || !first || first.type !== "strong" || firstText !== callout.type) {
     return;
   }
 
@@ -81,25 +134,30 @@ function removeLeadingLabel(paragraph, label) {
     next.value = next.value.replace(/^:\s*/, "").replace(/^\s+/, "");
     if (!next.value) paragraph.children.shift();
   }
+
+  cleanupParagraphStart(paragraph);
 }
 
 function transformBlockquote(node) {
   if (node.type !== "blockquote") return;
 
   const first = node.children?.[0];
-  const label = paragraphCalloutLabel(first);
-  if (!label) return;
+  const callout = paragraphCallout(first);
+  if (!callout) return;
 
-  removeLeadingLabel(first, label);
+  removeLeadingCallout(first, callout);
   if (first.children?.length === 0) {
     node.children.shift();
   }
 
+  if (callout.title) {
+    node.children.unshift(calloutTitleParagraph(callout.title));
+  }
+
   node.data = {
     hName: "aside",
     hProperties: {
-      className: ["callout", `callout-${label.toLowerCase()}`],
-      dataCalloutLabel: label,
+      className: ["callout", `callout-${callout.type}`],
     },
   };
 }

sites/reflections/src/styles/article.css

@@ -221,6 +221,15 @@
   margin-top: 0.8rem;
 }
 
+.article-content :where(.callout-title) {
+  margin: 0 0 0.45rem;
+  color: color-mix(in srgb, hsl(var(--primary)) 78%, hsl(var(--foreground)));
+  font-family: var(--font-fraunces);
+  font-size: 1rem;
+  font-weight: 650;
+  line-height: 1.35;
+}
+
 .article-content :where(.callout h1) {
   font-size: 1.35rem;
 }

sites/research/src/remark/callouts.mjs

@@ -1,19 +1,21 @@
-const CALLOUT_LABELS = new Map([
-  ["aside", "Aside"],
-  ["caution", "Caution"],
-  ["note", "Note"],
-  ["tip", "Tip"],
-  ["warning", "Warning"],
+const CALLOUT_TYPES = new Set([
+  "aside",
+  "caution",
+  "note",
+  "tip",
+  "warning",
 ]);
 
 const CALLOUT_MARKERS = new Map([
-  ["📝", "Note"],
-  ["💡", "Tip"],
-  ["⚡", "Tip"],
-  ["⚠️", "Warning"],
-  ["⚠", "Warning"],
+  ["📝", "note"],
+  ["💡", "tip"],
+  ["⚡", "tip"],
+  ["⚠️", "warning"],
+  ["⚠", "warning"],
 ]);
 
+const BRACKET_CALLOUT_PATTERN = /^\s*\[!(aside|caution|note|tip|warning)(?::\s*([^\]\r\n]+)|\|\s*([^\]\r\n]+))?\]\s*/i;
+
 function textFromInline(node) {
   if (!node) return "";
   if (typeof node.value === "string") return node.value;
@@ -21,7 +23,7 @@ function textFromInline(node) {
   return node.children.map(textFromInline).join("");
 }
 
-function normalizeLabel(value) {
+function normalizeType(value) {
   return value
     .trim()
     .replace(/^["“”]+|["“”]+$/g, "")
@@ -29,48 +31,99 @@ function normalizeLabel(value) {
     .toLowerCase();
 }
 
-function paragraphCalloutLabel(paragraph) {
+function calloutType(value) {
+  const type = normalizeType(value);
+  return CALLOUT_TYPES.has(type) ? type : null;
+}
+
+function parseBracketCallout(value) {
+  const match = value.match(BRACKET_CALLOUT_PATTERN);
+  if (!match) return null;
+
+  return {
+    kind: "bracket",
+    type: calloutType(match[1]),
+    title: (match[2] ?? match[3] ?? "").trim(),
+  };
+}
+
+function paragraphCallout(paragraph) {
   if (paragraph?.type !== "paragraph") return null;
 
   const first = paragraph.children?.[0];
   if (first?.type === "text") {
-    const match = first.value.match(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i);
-    if (match) {
-      return CALLOUT_LABELS.get(normalizeLabel(match[1]));
+    const bracket = parseBracketCallout(first.value);
+    if (bracket?.type) {
+      return bracket;
     }
 
     const trimmed = first.value.trimStart();
-    for (const [marker, label] of CALLOUT_MARKERS) {
+    for (const [marker, type] of CALLOUT_MARKERS) {
       if (trimmed.startsWith(marker)) {
-        return label;
+        return { kind: "marker", type, title: "", marker };
       }
     }
   }
 
   if (first?.type !== "strong") return null;
 
-  const label = CALLOUT_LABELS.get(normalizeLabel(textFromInline(first)));
-  if (!label) return null;
+  const type = calloutType(textFromInline(first));
+  if (!type) return null;
 
-  return label;
+  return { kind: "strong", type, title: "" };
 }
 
-function removeLeadingLabel(paragraph, label) {
+function cleanupParagraphStart(paragraph) {
+  while (paragraph.children?.length > 0) {
+    const first = paragraph.children[0];
+    if (first.type === "text") {
+      first.value = first.value.replace(/^\s+/, "");
+      if (first.value) return;
+      paragraph.children.shift();
+      continue;
+    }
+
+    if (first.type === "break") {
+      paragraph.children.shift();
+      continue;
+    }
+
+    return;
+  }
+}
+
+function calloutTitleParagraph(title) {
+  return {
+    type: "paragraph",
+    data: {
+      hName: "p",
+      hProperties: {
+        className: ["callout-title"],
+      },
+    },
+    children: [{ type: "text", value: title }],
+  };
+}
+
+function removeLeadingCallout(paragraph, callout) {
   if (paragraph?.type !== "paragraph") return;
 
   const first = paragraph.children?.[0];
-  if (first?.type === "text") {
-    first.value = first.value.replace(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i, "");
-    for (const marker of CALLOUT_MARKERS.keys()) {
-      const escapedMarker = marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
-      first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
-    }
-    if (!first.value) paragraph.children.shift();
+  if (callout.kind === "bracket" && first?.type === "text") {
+    first.value = first.value.replace(BRACKET_CALLOUT_PATTERN, "");
+    cleanupParagraphStart(paragraph);
     return;
   }
 
-  const firstText = normalizeLabel(textFromInline(first));
-  if (!first || first.type !== "strong" || firstText !== label.toLowerCase()) {
+  if (callout.kind === "marker" && first?.type === "text") {
+    const escapedMarker = callout.marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+    first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
+    cleanupParagraphStart(paragraph);
+    return;
+  }
+
+  const firstText = calloutType(textFromInline(first));
+  if (callout.kind !== "strong" || !first || first.type !== "strong" || firstText !== callout.type) {
     return;
   }
 
@@ -81,25 +134,30 @@ function removeLeadingLabel(paragraph, label) {
     next.value = next.value.replace(/^:\s*/, "").replace(/^\s+/, "");
     if (!next.value) paragraph.children.shift();
   }
+
+  cleanupParagraphStart(paragraph);
 }
 
 function transformBlockquote(node) {
   if (node.type !== "blockquote") return;
 
   const first = node.children?.[0];
-  const label = paragraphCalloutLabel(first);
-  if (!label) return;
+  const callout = paragraphCallout(first);
+  if (!callout) return;
 
-  removeLeadingLabel(first, label);
+  removeLeadingCallout(first, callout);
   if (first.children?.length === 0) {
     node.children.shift();
   }
 
+  if (callout.title) {
+    node.children.unshift(calloutTitleParagraph(callout.title));
+  }
+
   node.data = {
     hName: "aside",
     hProperties: {
-      className: ["callout", `callout-${label.toLowerCase()}`],
-      dataCalloutLabel: label,
+      className: ["callout", `callout-${callout.type}`],
     },
   };
 }

sites/research/src/styles/article.css

@@ -221,6 +221,15 @@
   margin-top: 0.8rem;
 }
 
+.article-content :where(.callout-title) {
+  margin: 0 0 0.45rem;
+  color: color-mix(in srgb, hsl(var(--primary)) 78%, hsl(var(--foreground)));
+  font-family: var(--font-fraunces);
+  font-size: 1rem;
+  font-weight: 650;
+  line-height: 1.35;
+}
+
 .article-content :where(.callout h1) {
   font-size: 1.35rem;
 }

sites/reviews/src/remark/callouts.mjs

@@ -1,19 +1,21 @@
-const CALLOUT_LABELS = new Map([
-  ["aside", "Aside"],
-  ["caution", "Caution"],
-  ["note", "Note"],
-  ["tip", "Tip"],
-  ["warning", "Warning"],
+const CALLOUT_TYPES = new Set([
+  "aside",
+  "caution",
+  "note",
+  "tip",
+  "warning",
 ]);
 
 const CALLOUT_MARKERS = new Map([
-  ["📝", "Note"],
-  ["💡", "Tip"],
-  ["⚡", "Tip"],
-  ["⚠️", "Warning"],
-  ["⚠", "Warning"],
+  ["📝", "note"],
+  ["💡", "tip"],
+  ["⚡", "tip"],
+  ["⚠️", "warning"],
+  ["⚠", "warning"],
 ]);
 
+const BRACKET_CALLOUT_PATTERN = /^\s*\[!(aside|caution|note|tip|warning)(?::\s*([^\]\r\n]+)|\|\s*([^\]\r\n]+))?\]\s*/i;
+
 function textFromInline(node) {
   if (!node) return "";
   if (typeof node.value === "string") return node.value;
@@ -21,7 +23,7 @@ function textFromInline(node) {
   return node.children.map(textFromInline).join("");
 }
 
-function normalizeLabel(value) {
+function normalizeType(value) {
   return value
     .trim()
     .replace(/^["“”]+|["“”]+$/g, "")
@@ -29,48 +31,99 @@ function normalizeLabel(value) {
     .toLowerCase();
 }
 
-function paragraphCalloutLabel(paragraph) {
+function calloutType(value) {
+  const type = normalizeType(value);
+  return CALLOUT_TYPES.has(type) ? type : null;
+}
+
+function parseBracketCallout(value) {
+  const match = value.match(BRACKET_CALLOUT_PATTERN);
+  if (!match) return null;
+
+  return {
+    kind: "bracket",
+    type: calloutType(match[1]),
+    title: (match[2] ?? match[3] ?? "").trim(),
+  };
+}
+
+function paragraphCallout(paragraph) {
   if (paragraph?.type !== "paragraph") return null;
 
   const first = paragraph.children?.[0];
   if (first?.type === "text") {
-    const match = first.value.match(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i);
-    if (match) {
-      return CALLOUT_LABELS.get(normalizeLabel(match[1]));
+    const bracket = parseBracketCallout(first.value);
+    if (bracket?.type) {
+      return bracket;
     }
 
     const trimmed = first.value.trimStart();
-    for (const [marker, label] of CALLOUT_MARKERS) {
+    for (const [marker, type] of CALLOUT_MARKERS) {
       if (trimmed.startsWith(marker)) {
-        return label;
+        return { kind: "marker", type, title: "", marker };
       }
     }
   }
 
   if (first?.type !== "strong") return null;
 
-  const label = CALLOUT_LABELS.get(normalizeLabel(textFromInline(first)));
-  if (!label) return null;
+  const type = calloutType(textFromInline(first));
+  if (!type) return null;
 
-  return label;
+  return { kind: "strong", type, title: "" };
 }
 
-function removeLeadingLabel(paragraph, label) {
+function cleanupParagraphStart(paragraph) {
+  while (paragraph.children?.length > 0) {
+    const first = paragraph.children[0];
+    if (first.type === "text") {
+      first.value = first.value.replace(/^\s+/, "");
+      if (first.value) return;
+      paragraph.children.shift();
+      continue;
+    }
+
+    if (first.type === "break") {
+      paragraph.children.shift();
+      continue;
+    }
+
+    return;
+  }
+}
+
+function calloutTitleParagraph(title) {
+  return {
+    type: "paragraph",
+    data: {
+      hName: "p",
+      hProperties: {
+        className: ["callout-title"],
+      },
+    },
+    children: [{ type: "text", value: title }],
+  };
+}
+
+function removeLeadingCallout(paragraph, callout) {
   if (paragraph?.type !== "paragraph") return;
 
   const first = paragraph.children?.[0];
-  if (first?.type === "text") {
-    first.value = first.value.replace(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i, "");
-    for (const marker of CALLOUT_MARKERS.keys()) {
-      const escapedMarker = marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
-      first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
-    }
-    if (!first.value) paragraph.children.shift();
+  if (callout.kind === "bracket" && first?.type === "text") {
+    first.value = first.value.replace(BRACKET_CALLOUT_PATTERN, "");
+    cleanupParagraphStart(paragraph);
     return;
   }
 
-  const firstText = normalizeLabel(textFromInline(first));
-  if (!first || first.type !== "strong" || firstText !== label.toLowerCase()) {
+  if (callout.kind === "marker" && first?.type === "text") {
+    const escapedMarker = callout.marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+    first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
+    cleanupParagraphStart(paragraph);
+    return;
+  }
+
+  const firstText = calloutType(textFromInline(first));
+  if (callout.kind !== "strong" || !first || first.type !== "strong" || firstText !== callout.type) {
     return;
   }
 
@@ -81,25 +134,30 @@ function removeLeadingLabel(paragraph, label) {
     next.value = next.value.replace(/^:\s*/, "").replace(/^\s+/, "");
     if (!next.value) paragraph.children.shift();
   }
+
+  cleanupParagraphStart(paragraph);
 }
 
 function transformBlockquote(node) {
   if (node.type !== "blockquote") return;
 
   const first = node.children?.[0];
-  const label = paragraphCalloutLabel(first);
-  if (!label) return;
+  const callout = paragraphCallout(first);
+  if (!callout) return;
 
-  removeLeadingLabel(first, label);
+  removeLeadingCallout(first, callout);
   if (first.children?.length === 0) {
     node.children.shift();
   }
 
+  if (callout.title) {
+    node.children.unshift(calloutTitleParagraph(callout.title));
+  }
+
   node.data = {
     hName: "aside",
     hProperties: {
-      className: ["callout", `callout-${label.toLowerCase()}`],
-      dataCalloutLabel: label,
+      className: ["callout", `callout-${callout.type}`],
     },
   };
 }

sites/reviews/src/styles/article.css

@@ -221,6 +221,15 @@
   margin-top: 0.8rem;
 }
 
+.article-content :where(.callout-title) {
+  margin: 0 0 0.45rem;
+  color: color-mix(in srgb, hsl(var(--primary)) 78%, hsl(var(--foreground)));
+  font-family: var(--font-fraunces);
+  font-size: 1rem;
+  font-weight: 650;
+  line-height: 1.35;
+}
+
 .article-content :where(.callout h1) {
   font-size: 1.35rem;
 }

sites/vibes/src/remark/callouts.mjs

@@ -1,19 +1,21 @@
-const CALLOUT_LABELS = new Map([
-  ["aside", "Aside"],
-  ["caution", "Caution"],
-  ["note", "Note"],
-  ["tip", "Tip"],
-  ["warning", "Warning"],
+const CALLOUT_TYPES = new Set([
+  "aside",
+  "caution",
+  "note",
+  "tip",
+  "warning",
 ]);
 
 const CALLOUT_MARKERS = new Map([
-  ["📝", "Note"],
-  ["💡", "Tip"],
-  ["⚡", "Tip"],
-  ["⚠️", "Warning"],
-  ["⚠", "Warning"],
+  ["📝", "note"],
+  ["💡", "tip"],
+  ["⚡", "tip"],
+  ["⚠️", "warning"],
+  ["⚠", "warning"],
 ]);
 
+const BRACKET_CALLOUT_PATTERN = /^\s*\[!(aside|caution|note|tip|warning)(?::\s*([^\]\r\n]+)|\|\s*([^\]\r\n]+))?\]\s*/i;
+
 function textFromInline(node) {
   if (!node) return "";
   if (typeof node.value === "string") return node.value;
@@ -21,7 +23,7 @@ function textFromInline(node) {
   return node.children.map(textFromInline).join("");
 }
 
-function normalizeLabel(value) {
+function normalizeType(value) {
   return value
     .trim()
     .replace(/^["“”]+|["“”]+$/g, "")
@@ -29,48 +31,99 @@ function normalizeLabel(value) {
     .toLowerCase();
 }
 
-function paragraphCalloutLabel(paragraph) {
+function calloutType(value) {
+  const type = normalizeType(value);
+  return CALLOUT_TYPES.has(type) ? type : null;
+}
+
+function parseBracketCallout(value) {
+  const match = value.match(BRACKET_CALLOUT_PATTERN);
+  if (!match) return null;
+
+  return {
+    kind: "bracket",
+    type: calloutType(match[1]),
+    title: (match[2] ?? match[3] ?? "").trim(),
+  };
+}
+
+function paragraphCallout(paragraph) {
   if (paragraph?.type !== "paragraph") return null;
 
   const first = paragraph.children?.[0];
   if (first?.type === "text") {
-    const match = first.value.match(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i);
-    if (match) {
-      return CALLOUT_LABELS.get(normalizeLabel(match[1]));
+    const bracket = parseBracketCallout(first.value);
+    if (bracket?.type) {
+      return bracket;
     }
 
     const trimmed = first.value.trimStart();
-    for (const [marker, label] of CALLOUT_MARKERS) {
+    for (const [marker, type] of CALLOUT_MARKERS) {
       if (trimmed.startsWith(marker)) {
-        return label;
+        return { kind: "marker", type, title: "", marker };
       }
     }
   }
 
   if (first?.type !== "strong") return null;
 
-  const label = CALLOUT_LABELS.get(normalizeLabel(textFromInline(first)));
-  if (!label) return null;
+  const type = calloutType(textFromInline(first));
+  if (!type) return null;
 
-  return label;
+  return { kind: "strong", type, title: "" };
 }
 
-function removeLeadingLabel(paragraph, label) {
+function cleanupParagraphStart(paragraph) {
+  while (paragraph.children?.length > 0) {
+    const first = paragraph.children[0];
+    if (first.type === "text") {
+      first.value = first.value.replace(/^\s+/, "");
+      if (first.value) return;
+      paragraph.children.shift();
+      continue;
+    }
+
+    if (first.type === "break") {
+      paragraph.children.shift();
+      continue;
+    }
+
+    return;
+  }
+}
+
+function calloutTitleParagraph(title) {
+  return {
+    type: "paragraph",
+    data: {
+      hName: "p",
+      hProperties: {
+        className: ["callout-title"],
+      },
+    },
+    children: [{ type: "text", value: title }],
+  };
+}
+
+function removeLeadingCallout(paragraph, callout) {
   if (paragraph?.type !== "paragraph") return;
 
   const first = paragraph.children?.[0];
-  if (first?.type === "text") {
-    first.value = first.value.replace(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i, "");
-    for (const marker of CALLOUT_MARKERS.keys()) {
-      const escapedMarker = marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
-      first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
-    }
-    if (!first.value) paragraph.children.shift();
+  if (callout.kind === "bracket" && first?.type === "text") {
+    first.value = first.value.replace(BRACKET_CALLOUT_PATTERN, "");
+    cleanupParagraphStart(paragraph);
     return;
   }
 
-  const firstText = normalizeLabel(textFromInline(first));
-  if (!first || first.type !== "strong" || firstText !== label.toLowerCase()) {
+  if (callout.kind === "marker" && first?.type === "text") {
+    const escapedMarker = callout.marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+    first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
+    cleanupParagraphStart(paragraph);
+    return;
+  }
+
+  const firstText = calloutType(textFromInline(first));
+  if (callout.kind !== "strong" || !first || first.type !== "strong" || firstText !== callout.type) {
     return;
   }
 
@@ -81,25 +134,30 @@ function removeLeadingLabel(paragraph, label) {
     next.value = next.value.replace(/^:\s*/, "").replace(/^\s+/, "");
     if (!next.value) paragraph.children.shift();
   }
+
+  cleanupParagraphStart(paragraph);
 }
 
 function transformBlockquote(node) {
   if (node.type !== "blockquote") return;
 
   const first = node.children?.[0];
-  const label = paragraphCalloutLabel(first);
-  if (!label) return;
+  const callout = paragraphCallout(first);
+  if (!callout) return;
 
-  removeLeadingLabel(first, label);
+  removeLeadingCallout(first, callout);
   if (first.children?.length === 0) {
     node.children.shift();
   }
 
+  if (callout.title) {
+    node.children.unshift(calloutTitleParagraph(callout.title));
+  }
+
   node.data = {
     hName: "aside",
     hProperties: {
-      className: ["callout", `callout-${label.toLowerCase()}`],
-      dataCalloutLabel: label,
+      className: ["callout", `callout-${callout.type}`],
     },
   };
 }

sites/vibes/src/styles/article.css

@@ -221,6 +221,15 @@
   margin-top: 0.8rem;
 }
 
+.article-content :where(.callout-title) {
+  margin: 0 0 0.45rem;
+  color: color-mix(in srgb, hsl(var(--primary)) 78%, hsl(var(--foreground)));
+  font-family: var(--font-fraunces);
+  font-size: 1rem;
+  font-weight: 650;
+  line-height: 1.35;
+}
+
 .article-content :where(.callout h1) {
   font-size: 1.35rem;
 }

src/remark-callouts.mjs

@@ -1,11 +1,21 @@
-const CALLOUT_LABELS = new Map([
-  ["aside", "Aside"],
-  ["caution", "Caution"],
-  ["note", "Note"],
-  ["tip", "Tip"],
-  ["warning", "Warning"],
+const CALLOUT_TYPES = new Set([
+  "aside",
+  "caution",
+  "note",
+  "tip",
+  "warning",
 ]);
 
+const CALLOUT_MARKERS = new Map([
+  ["📝", "note"],
+  ["💡", "tip"],
+  ["⚡", "tip"],
+  ["⚠️", "warning"],
+  ["⚠", "warning"],
+]);
+
+const BRACKET_CALLOUT_PATTERN = /^\s*\[!(aside|caution|note|tip|warning)(?::\s*([^\]\r\n]+)|\|\s*([^\]\r\n]+))?\]\s*/i;
+
 function textFromInline(node) {
   if (!node) return "";
   if (typeof node.value === "string") return node.value;
@@ -13,7 +23,7 @@ function textFromInline(node) {
   return node.children.map(textFromInline).join("");
 }
 
-function normalizeLabel(value) {
+function normalizeType(value) {
   return value
     .trim()
     .replace(/^["“”]+|["“”]+$/g, "")
@@ -21,37 +31,99 @@ function normalizeLabel(value) {
     .toLowerCase();
 }
 
-function paragraphCalloutLabel(paragraph) {
+function calloutType(value) {
+  const type = normalizeType(value);
+  return CALLOUT_TYPES.has(type) ? type : null;
+}
+
+function parseBracketCallout(value) {
+  const match = value.match(BRACKET_CALLOUT_PATTERN);
+  if (!match) return null;
+
+  return {
+    kind: "bracket",
+    type: calloutType(match[1]),
+    title: (match[2] ?? match[3] ?? "").trim(),
+  };
+}
+
+function paragraphCallout(paragraph) {
   if (paragraph?.type !== "paragraph") return null;
 
   const first = paragraph.children?.[0];
   if (first?.type === "text") {
-    const match = first.value.match(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i);
-    if (match) {
-      return CALLOUT_LABELS.get(normalizeLabel(match[1]));
+    const bracket = parseBracketCallout(first.value);
+    if (bracket?.type) {
+      return bracket;
+    }
+
+    const trimmed = first.value.trimStart();
+    for (const [marker, type] of CALLOUT_MARKERS) {
+      if (trimmed.startsWith(marker)) {
+        return { kind: "marker", type, title: "", marker };
+      }
     }
   }
 
   if (first?.type !== "strong") return null;
 
-  const label = CALLOUT_LABELS.get(normalizeLabel(textFromInline(first)));
-  if (!label) return null;
+  const type = calloutType(textFromInline(first));
+  if (!type) return null;
 
-  return label;
+  return { kind: "strong", type, title: "" };
 }
 
-function removeLeadingLabel(paragraph, label) {
+function cleanupParagraphStart(paragraph) {
+  while (paragraph.children?.length > 0) {
+    const first = paragraph.children[0];
+    if (first.type === "text") {
+      first.value = first.value.replace(/^\s+/, "");
+      if (first.value) return;
+      paragraph.children.shift();
+      continue;
+    }
+
+    if (first.type === "break") {
+      paragraph.children.shift();
+      continue;
+    }
+
+    return;
+  }
+}
+
+function calloutTitleParagraph(title) {
+  return {
+    type: "paragraph",
+    data: {
+      hName: "p",
+      hProperties: {
+        className: ["callout-title"],
+      },
+    },
+    children: [{ type: "text", value: title }],
+  };
+}
+
+function removeLeadingCallout(paragraph, callout) {
   if (paragraph?.type !== "paragraph") return;
 
   const first = paragraph.children?.[0];
-  if (first?.type === "text") {
-    first.value = first.value.replace(/^\s*\[!(aside|caution|note|tip|warning)\]\s*/i, "");
-    if (!first.value) paragraph.children.shift();
+  if (callout.kind === "bracket" && first?.type === "text") {
+    first.value = first.value.replace(BRACKET_CALLOUT_PATTERN, "");
+    cleanupParagraphStart(paragraph);
     return;
   }
 
-  const firstText = normalizeLabel(textFromInline(first));
-  if (!first || first.type !== "strong" || firstText !== label.toLowerCase()) {
+  if (callout.kind === "marker" && first?.type === "text") {
+    const escapedMarker = callout.marker.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+    first.value = first.value.replace(new RegExp(`^\\s*${escapedMarker}\\s*`, "u"), "");
+    cleanupParagraphStart(paragraph);
+    return;
+  }
+
+  const firstText = calloutType(textFromInline(first));
+  if (callout.kind !== "strong" || !first || first.type !== "strong" || firstText !== callout.type) {
     return;
   }
 
@@ -62,25 +134,30 @@ function removeLeadingLabel(paragraph, label) {
     next.value = next.value.replace(/^:\s*/, "").replace(/^\s+/, "");
     if (!next.value) paragraph.children.shift();
   }
+
+  cleanupParagraphStart(paragraph);
 }
 
 function transformBlockquote(node) {
   if (node.type !== "blockquote") return;
 
   const first = node.children?.[0];
-  const label = paragraphCalloutLabel(first);
-  if (!label) return;
+  const callout = paragraphCallout(first);
+  if (!callout) return;
 
-  removeLeadingLabel(first, label);
+  removeLeadingCallout(first, callout);
   if (first.children?.length === 0) {
     node.children.shift();
   }
 
+  if (callout.title) {
+    node.children.unshift(calloutTitleParagraph(callout.title));
+  }
+
   node.data = {
     hName: "aside",
     hProperties: {
-      className: ["callout", `callout-${label.toLowerCase()}`],
-      dataCalloutLabel: label,
+      className: ["callout", `callout-${callout.type}`],
     },
   };
 }

src/styles/article.css

@@ -200,6 +200,15 @@
   margin-top: 0.8rem;
 }
 
+.article-content :where(.callout-title) {
+  margin: 0 0 0.45rem;
+  color: color-mix(in srgb, hsl(var(--primary)) 78%, hsl(var(--foreground)));
+  font-family: var(--font-fraunces);
+  font-size: 1rem;
+  font-weight: 650;
+  line-height: 1.35;
+}
+
 .article-content :where(.callout h1) {
   font-size: 1.35rem;
 }