Saffron 디자인 시스템 적용: 브랜드 컬러 + Pretendard 폰트 + 크림 배경

- CSS 변수 기반 brand-50~950 컬러 팔레트 추가 (Tailwind @theme inline)
- Pretendard Variable 폰트 로드 및 기본 폰트로 설정
- 라이트모드 배경 #FFFAF5 크림색 적용 (다크모드 기본 유지)
- 전체 컴포넌트 orange-* → brand-* 마이그레이션
- 식당 리스트 채널명에 YouTube SVG 아이콘 추가
- 디자인 컨셉 문서 추가 (docs/design-concepts.md)

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

frontend/src/components/LoginMenu.tsx

@@ -15,7 +15,7 @@ export default function LoginMenu({ onGoogleSuccess }: LoginMenuProps) {
     <>
       <button
         onClick={() => setOpen(true)}
-        className="px-3 py-1.5 text-sm font-medium text-gray-600 dark:text-gray-300 hover:text-orange-600 dark:hover:text-orange-400 border border-gray-300 dark:border-gray-600 hover:border-orange-400 dark:hover:border-orange-500 rounded-lg transition-colors"
+        className="px-3 py-1.5 text-sm font-medium text-gray-600 dark:text-gray-300 hover:text-brand-600 dark:hover:text-brand-400 border border-gray-300 dark:border-gray-600 hover:border-brand-400 dark:hover:border-brand-500 rounded-lg transition-colors"
       >
         로그인
       </button>

frontend/src/components/MapView.tsx

@@ -231,7 +231,7 @@ export default function MapView({ restaurants, selected, onSelectRestaurant, onB
       {onMyLocation && (
         <button
           onClick={onMyLocation}
-          className="absolute top-2 right-2 w-9 h-9 bg-white dark:bg-gray-900 rounded-lg shadow-md flex items-center justify-center text-gray-600 dark:text-gray-300 hover:text-orange-500 dark:hover:text-orange-400 transition-colors z-10"
+          className="absolute top-2 right-2 w-9 h-9 bg-white dark:bg-gray-900 rounded-lg shadow-md flex items-center justify-center text-gray-600 dark:text-gray-300 hover:text-brand-500 dark:hover:text-brand-400 transition-colors z-10"
           title="내 위치"
         >
           <svg viewBox="0 0 24 24" className="w-5 h-5 fill-current">

frontend/src/components/RestaurantDetail.tsx

@@ -117,7 +117,7 @@ export default function RestaurantDetail({
         {restaurant.phone && (
           <p>
             <span className="text-gray-500 dark:text-gray-400">전화:</span>{" "}
-            <a href={`tel:${restaurant.phone}`} className="text-orange-600 dark:text-orange-400 hover:underline">
+            <a href={`tel:${restaurant.phone}`} className="text-brand-600 dark:text-brand-400 hover:underline">
               {restaurant.phone}
             </a>
           </p>
@@ -128,7 +128,7 @@ export default function RestaurantDetail({
               href={`https://www.google.com/maps/search/?api=1&query=${encodeURIComponent(restaurant.name + (restaurant.address ? " " + restaurant.address : restaurant.region ? " " + restaurant.region.replace(/\|/g, " ") : ""))}`}
               target="_blank"
               rel="noopener noreferrer"
-              className="text-orange-600 dark:text-orange-400 hover:underline text-xs"
+              className="text-brand-600 dark:text-brand-400 hover:underline text-xs"
             >
               Google Maps에서 보기
             </a>
@@ -223,7 +223,7 @@ export default function RestaurantDetail({
                     {v.foods_mentioned.map((f, i) => (
                       <span
                         key={i}
-                        className="px-2 py-0.5 bg-orange-50 dark:bg-orange-900/30 text-orange-700 dark:text-orange-400 rounded text-xs"
+                        className="px-2 py-0.5 bg-brand-50 dark:bg-brand-900/30 text-brand-700 dark:text-brand-400 rounded text-xs"
                       >
                         {f}
                       </span>

frontend/src/components/RestaurantList.tsx

@@ -39,7 +39,7 @@ export default function RestaurantList({
           onClick={() => onSelect(r)}
           className={`w-full text-left p-3 rounded-xl shadow-sm border transition-all hover:shadow-md hover:-translate-y-0.5 ${
             selectedId === r.id
-              ? "bg-orange-50 dark:bg-orange-900/20 border-orange-300 dark:border-orange-700 shadow-orange-100 dark:shadow-orange-900/10"
+              ? "bg-brand-50 dark:bg-brand-900/20 border-brand-300 dark:border-brand-700 shadow-brand-100 dark:shadow-brand-900/10"
               : "bg-white dark:bg-gray-900 border-gray-100 dark:border-gray-800 hover:bg-gray-50 dark:hover:bg-gray-800"
           }`}
         >
@@ -70,7 +70,7 @@ export default function RestaurantList({
               {r.foods_mentioned.slice(0, 5).map((f, i) => (
                 <span
                   key={i}
-                  className="px-1.5 py-0.5 bg-orange-50 dark:bg-orange-900/30 text-orange-700 dark:text-orange-400 rounded text-[10px]"
+                  className="px-1.5 py-0.5 bg-brand-50 dark:bg-brand-900/30 text-brand-700 dark:text-brand-400 rounded text-[10px]"
                 >
                   {f}
                 </span>
@@ -85,8 +85,9 @@ export default function RestaurantList({
               {r.channels.map((ch) => (
                 <span
                   key={ch}
-                  className="px-1.5 py-0.5 bg-orange-50 dark:bg-orange-900/30 text-orange-600 dark:text-orange-400 rounded-full text-[10px] font-medium"
+                  className="inline-flex items-center gap-0.5 px-1.5 py-0.5 bg-brand-50 dark:bg-brand-900/30 text-brand-600 dark:text-brand-400 rounded-full text-[10px] font-medium"
                 >
+                  <svg className="w-2.5 h-2.5 shrink-0 text-red-400" viewBox="0 0 24 24" fill="currentColor"><path d="M23.498 6.186a3.016 3.016 0 0 0-2.122-2.136C19.505 3.545 12 3.545 12 3.545s-7.505 0-9.377.505A3.017 3.017 0 0 0 .502 6.186C0 8.07 0 12 0 12s0 3.93.502 5.814a3.016 3.016 0 0 0 2.122 2.136c1.871.505 9.376.505 9.376.505s7.505 0 9.377-.505a3.015 3.015 0 0 0 2.122-2.136C24 15.93 24 12 24 12s0-3.93-.502-5.814zM9.545 15.568V8.432L15.818 12l-6.273 3.568z"/></svg>
                   {ch}
                 </span>
               ))}

frontend/src/components/ReviewSection.tsx

@@ -124,7 +124,7 @@ function ReviewForm({
         <button
           type="submit"
           disabled={submitting}
-          className="px-3 py-1 bg-orange-500 dark:bg-orange-600 text-white text-sm rounded hover:bg-orange-600 dark:hover:bg-orange-500 disabled:opacity-50"
+          className="px-3 py-1 bg-brand-500 dark:bg-brand-600 text-white text-sm rounded hover:bg-brand-600 dark:hover:bg-brand-500 disabled:opacity-50"
         >
           {submitting ? "저장 중..." : submitLabel}
         </button>
@@ -225,7 +225,7 @@ export default function ReviewSection({ restaurantId }: ReviewSectionProps) {
           {user && !myReview && !showForm && (
             <button
               onClick={() => setShowForm(true)}
-              className="mb-3 px-3 py-1 bg-orange-500 dark:bg-orange-600 text-white text-sm rounded hover:bg-orange-600 dark:hover:bg-orange-500"
+              className="mb-3 px-3 py-1 bg-brand-500 dark:bg-brand-600 text-white text-sm rounded hover:bg-brand-600 dark:hover:bg-brand-500"
             >
               리뷰 작성
             </button>

frontend/src/components/SearchBar.tsx

@@ -36,11 +36,11 @@ export default function SearchBar({ onSearch, isLoading }: SearchBarProps) {
         value={query}
         onChange={(e) => setQuery(e.target.value)}
         placeholder="식당, 지역, 음식 검색..."
-        className="w-full pl-9 pr-3 py-2 bg-gray-100 dark:bg-gray-800 border border-transparent focus:border-orange-400 focus:bg-white dark:focus:bg-gray-900 rounded-xl text-sm outline-none transition-all dark:text-gray-200 dark:placeholder-gray-500"
+        className="w-full pl-9 pr-3 py-2 bg-gray-100 dark:bg-gray-800 border border-transparent focus:border-brand-400 focus:bg-white dark:focus:bg-gray-900 rounded-xl text-sm outline-none transition-all dark:text-gray-200 dark:placeholder-gray-500"
       />
       {isLoading && (
         <div className="absolute right-3 top-1/2 -translate-y-1/2">
-          <div className="w-4 h-4 border-2 border-orange-400 border-t-transparent rounded-full animate-spin" />
+          <div className="w-4 h-4 border-2 border-brand-400 border-t-transparent rounded-full animate-spin" />
         </div>
       )}
     </form>