diff --git a/public/changelog.txt b/public/changelog.txt
new file mode 100644
index 0000000..13426c6
--- /dev/null
+++ b/public/changelog.txt
@@ -0,0 +1,2 @@
+2025.09.19 更新了单词板，单词不再会重叠。
+2025.09.25 优化了主界面UI
diff --git a/src/constants.ts b/src/constants.ts
new file mode 100644
index 0000000..a01d175
--- /dev/null
+++ b/src/constants.ts
@@ -0,0 +1,4 @@
+export const BOARD_WIDTH = 1000;
+export const BOARD_HEIGHT = 600;
+export const TEXT_SIZE = 30;
+export const TEXT_WIDTH = TEXT_SIZE * 0.6;
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