From c86227faf973d8f553da8186e0527cf397a6cd39 Mon Sep 17 00:00:00 2001
From: tiennm99 <tiennm99@outlook.com>
Date: Mon, 20 Apr 2026 22:45:49 +0700
Subject: [PATCH] fix(wordle): render letters as emoji-class characters for
 exact alignment
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Previous fullwidth-Latin approach (U+FF21..FF3A) failed on mobile
Telegram clients because their monospace fonts don't ship fullwidth
glyphs — the codepoints fall back to base Latin at 1 cell, making the
letter row half as wide as the marker row.

Switch to Negative Squared Latin Capital Letters (U+1F170..1F189,
🅰🅱🅲..🆉) — these are emoji-class characters, so both rows are
drawn by the same emoji font at the same cell width. Column alignment
becomes a property of Unicode, not of the client's monospace font.

  🟩🟨⬜🟩🟩
  🅲🆁🅰🅽🅴
---
 src/modules/wordle/render.js | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/modules/wordle/render.js b/src/modules/wordle/render.js
index 5210794..a35b1e6 100644
--- a/src/modules/wordle/render.js
+++ b/src/modules/wordle/render.js
@@ -15,22 +15,26 @@
 
 const MARKER = { correct: "🟩", partial: "🟨", wrong: "⬜" };
 
-// In a Telegram <pre> block, color-square emoji render at ~2 monospace cells
-// wide, while ASCII letters render at 1 cell — so a plain "A B C" row never
-// lines up under the markers. Fullwidth Latin (U+FF21..U+FF3A) is East Asian
-// Width = Fullwidth, which renders at exactly 2 cells per character and
-// matches the emoji column width 1-to-1.
-const FULLWIDTH_OFFSET = 0xff21 - 0x41; // 'A' (0x41) → 'Ａ' (0xFF21)
+// Alignment under Telegram <pre>: the color markers are emoji; to guarantee
+// the letter row is the same width, render letters as emoji too. Unicode
+// block "Enclosed Alphanumeric Supplement" has emoji-class capitals at
+// U+1F170..FF189 (🅰🅱🅲..🆉 — "Negative Squared Latin Capital Letter").
+// Because both rows draw from the emoji font, column widths match 1-to-1
+// on every client, regardless of the monospace font shipped with it.
+const EMOJI_A = 0x1f170;
+const ASCII_A = 0x41;
 
-function toFullwidthUpper(ch) {
+function toEmojiLetter(ch) {
   const code = ch.toUpperCase().charCodeAt(0);
-  if (code >= 0x41 && code <= 0x5a) return String.fromCharCode(code + FULLWIDTH_OFFSET);
+  if (code >= ASCII_A && code <= 0x5a) {
+    return String.fromCodePoint(EMOJI_A + (code - ASCII_A));
+  }
   return ch;
 }
 
 function rowPair(results) {
   const markers = results.map((r) => MARKER[r.result] ?? "⬜").join("");
-  const letters = results.map((r) => toFullwidthUpper(r.letter)).join("");
+  const letters = results.map((r) => toEmojiLetter(r.letter)).join("");
   return `${markers}\n${letters}`;
 }