Fix referral invite mobile layout

Author: jinwandalaohu66

docs/referral/referral.css

@@ -234,18 +234,33 @@ html[lang="en"] .language-toggle [data-lang="en"] {
 
 .invite-code {
   margin: 26px auto 18px;
+  width: 100%;
+  max-width: 100%;
   color: var(--ink);
   font-family: var(--mono);
-  font-size: clamp(50px, 15vw, 84px);
+  font-size: clamp(46px, 13vw, 84px);
   font-weight: 520;
-  letter-spacing: 0.22em;
+  letter-spacing: 0.18em;
   line-height: 1;
   text-align: center;
-  text-indent: 0.22em;
+  text-indent: 0.18em;
   white-space: nowrap;
+  overflow: hidden;
   transform: translateZ(0);
 }
 
+.invite-code.compact {
+  font-size: clamp(38px, 10.6vw, 64px);
+  letter-spacing: 0.12em;
+  text-indent: 0.12em;
+}
+
+.invite-code.ultra-compact {
+  font-size: clamp(32px, 8.8vw, 52px);
+  letter-spacing: 0.08em;
+  text-indent: 0.08em;
+}
+
 .invite-code span {
   display: inline-block;
   animation: codeEnter 760ms var(--ease) both;
@@ -661,7 +676,8 @@ html[lang="en"] .language-toggle [data-lang="en"] {
   .invite-code {
     margin-left: 0;
     text-align: left;
-    text-indent: 0.22em;
+    text-indent: 0.18em;
+    overflow: visible;
   }
 
   .actions {

docs/referral/referral.js

@@ -33,7 +33,7 @@ const copy = {
     valid: [
       ["首次使用的新用户", "老用户、重复设备和自邀不会计入"],
       ["绑定邀请码", "被邀请人只能绑定一次邀请码"],
-      ["完成核心行为", "运行 Python、创建项目或使用 AI 功能"],
+      ["完成核心行为", "运行 Python 或使用 AI 功能"],
       ["次日仍打开 App", "完成留存验证后才计入有效邀请"],
     ],
     other: [
@@ -73,7 +73,7 @@ const copy = {
     valid: [
       ["A first-time new user", "Existing users, duplicate devices, and self-invites are excluded"],
       ["Invite code is bound", "Each invited user can bind only one code"],
-      ["Core action completed", "Run Python, create a project, or use AI"],
+      ["Core action completed", "Run Python or use AI"],
       ["Returns the next day", "Retention must be verified before it becomes valid"],
     ],
     other: [
@@ -199,6 +199,9 @@ function renderInviteCode(code) {
   const target = document.querySelector("[data-invite-code]");
   if (!target) return;
   target.dataset.inviteCode = code;
+  target.dataset.length = String(code.length);
+  target.classList.toggle("compact", code.length >= 7);
+  target.classList.toggle("ultra-compact", code.length >= 10);
   target.innerHTML = code.split("").map((char, index) => `<span style="--i:${index}">${char}</span>`).join("");
 }