Add EN/JA RFC2119 quiz and update authoring manifest

Author: thinksyncs

education/quiz.css

@@ -1,4 +1,7 @@
 :root{
+  --font-sans: system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,"Apple Color Emoji","Segoe UI Emoji";
+  --font-sans-ja: system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,"Hiragino Sans","Hiragino Kaku Gothic ProN","Yu Gothic","Meiryo","Apple Color Emoji","Segoe UI Emoji";
+  --font-mono: ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;
   --bg-gradient-top:#0b0f14;
   --bg-gradient-bottom:#0d141c;
   --fg:#e7eef6;
@@ -17,8 +20,12 @@
 }
 *{box-sizing:border-box}
 html,body{height:100%}
-body{margin:0;background:linear-gradient(180deg,var(--bg-gradient-top),var(--bg-gradient-top) 40%,var(--bg-gradient-bottom) 100%);color:var(--fg);font:16px/1.6 system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,"Apple Color Emoji","Segoe UI Emoji";transition:background .3s ease,color .3s ease}
+body{margin:0;background:linear-gradient(180deg,var(--bg-gradient-top),var(--bg-gradient-top) 40%,var(--bg-gradient-bottom) 100%);color:var(--fg);font:17px/1.75 var(--font-sans);text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;transition:background .3s ease,color .3s ease}
+html[lang="ja"] body{font-family:var(--font-sans-ja)}
 a{color:var(--accent)}
+.q h4{line-height:1.35}
+code,pre,kbd,samp{font-family:var(--font-mono)}
+code{font-size:.95em}
 .container{max-width:980px;margin:0 auto;padding:28px 16px 48px}
 header{display:flex;gap:16px;align-items:center;justify-content:space-between;margin-bottom:12px;flex-wrap:wrap}
 h1{font-size:clamp(20px,3.6vw,34px);margin:0 0 6px}