style: standardize design token classes and spacing units

Standardize styling across all components:
1. Replace legacy color utilities and hardcoded hex values with official design token classes
2. Update margin/padding/rounded corner values to use wrapped [px] syntax for consistency
3. Fix inconsistent line-height class names to use leading-[value] format

src/pages/home/components/LongTextGuideCardPreview/index.vue

@@ -2,7 +2,7 @@
   <div class="w-full bg-white  border-ff overflow-hidden rounded-20 flex flex-col">
     <!-- 占位撑开 -->
     <div class="w-vw"></div>
-    <div class="flex flex-col px-16 pt-16 pb-12 " @click="openDetail(item)">
+    <div class="flex flex-col px-16 pt-16 pb-[12px] " @click="openDetail(item)">
 
       <div class="long-text-guide-card__badge text-[12px] font-900" :class="`is-${item.badgeTone}`">
         {{ item.badge }}