feat: use twemoji to display flags in win

src/assets/styles/fonts.scss

@@ -0,0 +1,16 @@
+// 这个字体是为了解决在 Windows 系统下，微软因为政策问题，不支持显示国旗 emoji 的问题
+@font-face {
+  font-family: "Color Emoji Flags";
+  src: local("Apple Color Emoji"), local("Noto Color Emoji"),
+    url("../fonts/Twemoji.Mozilla.ttf");
+  unicode-range: U+1F1E6-1F1FF;
+}
+
+@font-face {
+  font-family: "Color Emoji";
+  src: local("Apple Color Emoji"), local("Segoe UI Emoji"),
+    local("Segoe UI Symbol"), local("Noto Color Emoji"),
+    url("../fonts/Twemoji.Mozilla.ttf");
+
+  // use local emoji font for better backward compatibility
+}

src/assets/styles/index.scss

@@ -1,12 +1,22 @@
 @import "./layout.scss";
 @import "./page.scss";
+@import "./fonts.scss";
 
 body {
   margin: 0;
   overflow: hidden;
-  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen",
-    "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue",
-    sans-serif;
+  font-family:
+    system-ui,
+    -apple-system,
+    BlinkMacSystemFont,
+    Segoe UI,
+    Roboto,
+    "Helvetica Neue",
+    Arial,
+    "Noto Sans",
+    sans-serif,
+    "Color Emoji Flags",
+    "Color Emoji";
   user-select: none;
   -webkit-font-smoothing: antialiased;
 }

src/pages/_theme.tsx

@@ -8,7 +8,7 @@ export const defaultTheme = {
   error_color: "#d32f2f",
   warning_color: "#ed6c02",
   success_color: "#2e7d32",
-  font_family: `"Roboto", "Helvetica", "Arial", sans-serif`,
+  font_family: `"Roboto", "Helvetica", "Arial", sans-serif, "Color Emoji Flags"," Color Emoji"`,
 };
 
 // dark mode