design: 전 사이트 AI 템플릿 그라디언트 완전 제거 (Round 5)

- services/website: featured 가격 카드 linear-gradient → #0d1240 솔리드
- saju/input: blur-3xl orb + radial-gradient 도트 패턴 제거, bg-gradient-to-br → 솔리드+대각 패턴
- payment/fail + success: 헤더 그라디언트→#04102b, 로고 아이콘→#1a56db, 버튼→#1a56db 솔리드
- mypage: 탭 활성 상태·액센트 라인·버튼 전체 gradient → 솔리드 (#1a56db/amber-500)
  amber 알림 카드 gradient → bg-amber-50, 사주 결과 버튼 → #04102b

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

app/payment/fail/page.tsx

@@ -26,7 +26,7 @@ function FailContent() {
       <div className="flex justify-center gap-3 flex-wrap">
         <button
           onClick={() => window.history.back()}
-          className="inline-flex items-center gap-2 bg-gradient-to-r from-blue-600 to-violet-600 text-white px-6 py-3 rounded-xl font-semibold text-sm shadow-lg shadow-blue-600/20"
+          className="inline-flex items-center gap-2 bg-[#1a56db] hover:bg-[#1e4fc2] text-white px-6 py-3 rounded-xl font-semibold text-sm shadow-lg shadow-blue-600/20 transition"
         >
           다시 시도하기
         </button>
@@ -45,9 +45,9 @@ export default function PaymentFailPage() {
   return (
     <div className="min-h-full bg-[#f0f5ff] flex items-center justify-center px-6 py-16">
       <div className="w-full max-w-md bg-white rounded-2xl border border-[#dbe8ff] shadow-lg overflow-hidden">
-        <div className="bg-gradient-to-r from-[#04102b] to-[#0a1f5c] px-6 py-4">
+        <div className="bg-[#04102b] px-6 py-4" style={{ backgroundImage: 'repeating-linear-gradient(135deg, rgba(255,255,255,0.012) 0px, rgba(255,255,255,0.012) 1px, transparent 1px, transparent 40px)' }}>
           <div className="flex items-center gap-2">
-            <div className="w-7 h-7 rounded-lg bg-gradient-to-br from-blue-500 to-violet-600 flex items-center justify-center text-white font-bold text-xs">
+            <div className="w-7 h-7 rounded-lg bg-[#1a56db] flex items-center justify-center text-white font-bold text-xs">
               쟁
             </div>
             <span className="text-white font-bold text-sm">쟁승메이드 결제</span>