fix: 3 display bugs found in full-page audit

1. MacroVibesPageClient — funding stats rendered "undefined%" when
   latest_rate_pct / last_24h_avg_pct were null. `?.toFixed()` returns
   undefined inside a template literal → shows as the string "undefined%".
   Fixed: explicit null check → '—' fallback.

2. SettingsClient — broken internal anchor: href="#btc-settings-panel"
   but the section id is "btc-settings". "Open panel ↓" link did nothing.
   Fixed: corrected href to "#btc-settings".

3. KolPageClient — undefined CSS variables throughout the file:
   --bg-card (transparent) and --border (no border) were never defined
   in the design system (globals.css uses --surface and --line).
   KOL cards rendered with transparent bg and invisible borders.
   Fixed: --bg-card → --surface, --border → --line, --accent → --amber.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/[locale]/kol/KolPageClient.tsx

@@ -163,8 +163,8 @@ function DigestWidget({
   return (
     <div style={{
       marginBottom: 16, padding: 'clamp(12px, 3vw, 18px)',
-      borderRadius: 12, background: 'var(--bg-card)',
+      borderRadius: 12, background: 'var(--surface)',
-      border: '1px solid var(--border)',
+      border: '1px solid var(--line)',
     }}>
       <div style={{
         display: 'flex', justifyContent: 'space-between',
@@ -451,8 +451,8 @@ function WalletCheckWidget({
   return (
     <div style={{
       marginBottom: 16, padding: 'clamp(12px, 3vw, 18px)',
-      borderRadius: 12, background: 'var(--bg-card)',
+      borderRadius: 12, background: 'var(--surface)',
-      border: '1px solid var(--border)',
+      border: '1px solid var(--line)',
     }}>
       <div style={{
         display: 'flex', justifyContent: 'space-between',
@@ -506,7 +506,7 @@ function WalletCheckWidget({
               padding: '14px 16px',
               borderRadius: 12,
               background: 'var(--bg-sunk)',
-              border: '1px solid var(--border)',
+              border: '1px solid var(--line)',
             }}>
               <div style={{ minWidth: 0 }}>
                 <div style={{ display: 'flex', alignItems: 'center', gap: 8, marginBottom: 6, flexWrap: 'wrap' }}>
@@ -860,7 +860,7 @@ export default function KolPage({
           <button
             onClick={() => setTickerFilter(null)}
             style={{
-              background: 'var(--bg-sunk)', border: '1px solid var(--border)',
+              background: 'var(--bg-sunk)', border: '1px solid var(--line)',
               borderRadius: 4, padding: '2px 8px',
               cursor: 'pointer', fontSize: 11, color: 'var(--ink-2)',
             }}
@@ -901,13 +901,13 @@ export default function KolPage({
               onClick={() => openDetail(p.id)}
               style={{
                 padding: 14, borderRadius: 10,
-                background: 'var(--bg-card)',
+                background: 'var(--surface)',
-                border: '1px solid var(--border)',
+                border: '1px solid var(--line)',
                 cursor: 'pointer',
                 transition: 'border-color 0.15s',
               }}
-              onMouseEnter={e => (e.currentTarget.style.borderColor = 'var(--accent)')}
+              onMouseEnter={e => (e.currentTarget.style.borderColor = 'var(--amber)')}
-              onMouseLeave={e => (e.currentTarget.style.borderColor = 'var(--border)')}
+              onMouseLeave={e => (e.currentTarget.style.borderColor = 'var(--line)')}
             >
               {/* 顶部：作者 + 右侧操作区 */}
               <div style={{ display: 'flex', justifyContent: 'space-between',

app/[locale]/macro/MacroVibesPageClient.tsx

@@ -274,12 +274,12 @@ function FundingPanel({
       }}>
         <StatBox
           label="Latest cycle"
-          value={`${snap.latest_rate_pct?.toFixed(4)}%`}
+          value={snap.latest_rate_pct == null ? '—' : `${snap.latest_rate_pct.toFixed(4)}%`}
           hint="The most recent funding payment, in % per cycle. Positive = longs pay shorts."
         />
         <StatBox
           label="Last 24h avg"
-          value={`${snap.last_24h_avg_pct?.toFixed(4)}%`}
+          value={snap.last_24h_avg_pct == null ? '—' : `${snap.last_24h_avg_pct.toFixed(4)}%`}
           hint="Average of the last 24 hours of funding cycles. Smooths out one-off prints."
         />
         <StatBox

app/[locale]/settings/SettingsClient.tsx

@@ -85,7 +85,7 @@ export default function SettingsClient() {
           <div className="settings-scope-copy">
             Strategy mode, BTC leverage, and de-risk behavior used by the Macro Vibes sleeve.
           </div>
-          <a href="#btc-settings-panel" className="settings-scope-link">Open panel ↓</a>
+          <a href="#btc-settings" className="settings-scope-link">Open panel ↓</a>
         </section>
 
         <section id="global-settings" className="settings-scope-card global">