fix: hero 字母不可见 (渐变不继承) + 升级 text.splitText API

- .hero-letter 加自己的渐变 + -webkit-background-clip:text
  原因: 父 h1 的 -webkit-text-fill-color:transparent 继承到 span 但
  background 不继承，span 变成 box 就切断 background-clip:text 的连贯，
  span 里文字就全透明看不见

- text.split(...) → text.splitText(...)
  修掉 v4.3 的 deprecation warning

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.memory/worklog.json

@@ -209,6 +209,20 @@
       "message": "chore: gitignore playwright QA 产物",
       "hash": "47c45e3",
       "files_changed": 1
+    },
+    {
+      "ts": "2026-04-24T01:12:29+08:00",
+      "type": "commit",
+      "message": "auto-save 2026-04-24 01:12 (+1, ~2)",
+      "hash": "71ad32f",
+      "files_changed": 3
+    },
+    {
+      "ts": "2026-04-24T01:16:46+08:00",
+      "type": "commit",
+      "message": "feat: 加 8 个 Live Demo + hero 文字 stagger 动画",
+      "hash": "d24821c",
+      "files_changed": 1
     }
   ]
 }

index.html

@@ -266,8 +266,13 @@
     will-change:transform;
   }
 
-  /* hero animated logo */
-  h1 .hero-letter{display:inline-block;will-change:transform,opacity,color}
+  /* hero animated logo —— 每个字母自带渐变剪影（父级 -webkit-text-fill-color:transparent 不继承背景，这里补回） */
+  h1 .hero-letter{
+    display:inline-block;will-change:transform,opacity,color;
+    background:linear-gradient(135deg,var(--accent) 0%,var(--accent3) 55%,var(--accent2) 100%);
+    -webkit-background-clip:text;background-clip:text;
+    -webkit-text-fill-color:transparent;
+  }
 
   /* online badge */
   .live-badge{
@@ -1591,8 +1596,8 @@ stickys.<span class="fn">forEach</span>(s =&gt; s.<span class="fn">revert</span>
   let splitInstance = null;
   function ensureSplit() {
     if (splitInstance) splitInstance.revert && splitInstance.revert();
-    if (text && text.split) {
-      splitInstance = text.split(textTarget, { chars: { class: 'letter' } });
+    if (text && text.splitText) {
+      splitInstance = text.splitText(textTarget, { chars: { class: 'letter' } });
     }
   }
   function textDemo(kind) {