From cb5a703210e00bfb69395b474a276f11c4a918d4 Mon Sep 17 00:00:00 2001
From: Beta-Devin AI
 <248786709+beta-devin-ai-integration[bot]@users.noreply.github.com>
Date: Mon, 23 Mar 2026 22:23:59 +0000
Subject: [PATCH] Fix biased shuffle algorithm, broken CSS background-color,
 and implicit global variables

- Fix shuffle(): replace broken implementation with correct Fisher-Yates (Durstenfeld) algorithm. The old version used rand(i) which only selected from indices [0, i-1], producing heavily biased permutations where most orderings were unreachable.
- Fix settings modal background-color: add missing '#' prefix to hex color value (000000 -> #000000), introduced in Options panel WIP commit.
- Fix implicit global variable 'z' in isStandardSet() and isSuperSet(): add 'var' declaration to for-of loops to prevent global scope pollution.

Co-Authored-By: scott.wu46+coggitgrant323@gmail.com <scott.wu46@gmail.com>
---
 public/header.js   | 6 +++---
 public/index.css   | 2 +-
 public/variants.js | 6 +++---
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/public/header.js b/public/header.js
index faf8aed..4bcf110 100644
--- a/public/header.js
+++ b/public/header.js
@@ -20,9 +20,9 @@ function rand(x) {
 }
 
 function shuffle(lst) {
-  for (var i = 0; i < lst.length; ++i) {
-    var tmp = lst[i]
-    var j = rand(i);
+  for (var i = lst.length - 1; i > 0; --i) {
+    var j = Math.floor(Math.random() * (i + 1));
+    var tmp = lst[i];
     lst[i] = lst[j];
     lst[j] = tmp;
   }
diff --git a/public/index.css b/public/index.css
index a9157f4..34eb834 100644
--- a/public/index.css
+++ b/public/index.css
@@ -254,7 +254,7 @@ svg .stripe.purple {
     padding: 20px;
     border: 1px solid #888;
     width: 80%; /* Could be more or less, depending on screen size */
-    background-color: 000000;
+    background-color: #000000;
 }
 
 /* The Close Button */
diff --git a/public/variants.js b/public/variants.js
index 4261157..391b4dd 100644
--- a/public/variants.js
+++ b/public/variants.js
@@ -20,7 +20,7 @@ function isNotNull(set) {
 
 function isStandardSet(set) {
   if (isNotNull(set) && set.length == 3) {
-    for (z of ['count', 'color', 'shading', 'shape']) {
+    for (var z of ['count', 'color', 'shading', 'shape']) {
       var a = set[0][z], b = set[1][z], c = set[2][z];
       if ((a + b + c) % 3 != 0) {
         return false;
@@ -35,7 +35,7 @@ function isSuperSet(set) {
   if (isNotNull(set) && set.length == 4) {
     for (var j of [1, 2, 3]) {
       var cnt = 0;
-      for (z of ['count', 'color', 'shading', 'shape']) {
+      for (var z of ['count', 'color', 'shading', 'shape']) {
         var a = set[0][z], b = set[j][z];
         var cd = set[1][z] + set[2][z] + set[3][z] - b;
         if ((a + b - cd) % 3 != 0) {
@@ -220,4 +220,4 @@ Variants = {
   superset: superset,
   hiddenset: hiddenset,
   powerset: powerset
-}
\ No newline at end of file
+}