diff --git a/src/frontend/src/components/ui/Button.tsx b/src/frontend/src/components/ui/Button.tsx
index 65f0815..632a2f3 100644
--- a/src/frontend/src/components/ui/Button.tsx
+++ b/src/frontend/src/components/ui/Button.tsx
@@ -2,27 +2,41 @@ import type { ButtonHTMLAttributes, ReactNode } from 'react';
 import './button.css';
 
 type Variant = 'primary' | 'secondary' | 'ai' | 'ghost' | 'danger';
+type Size = 'sm' | 'md' | 'lg';
 
 interface ButtonProps extends ButtonHTMLAttributes<HTMLButtonElement> {
   variant?: Variant;
+  /** Nifty 3단 크기 — sm(32) · md(40, 기본) · lg(48). */
+  size?: Size;
   leadingIcon?: ReactNode;
+  /** 정사각 아이콘 전용 버튼(aria-label 필수). */
+  iconOnly?: boolean;
   block?: boolean;
 }
 
-/** design.md §1-4 — 주요 버튼(primary blue), AI 액션(ai-accent 보라). radius 4px. */
+/** design.md §1-4 / DESIGN_SYSTEM_NIFTY §2.1 — 주요 버튼(primary blue), AI 액션(ai-accent 보라). radius 4px. */
 export function Button({
   variant = 'primary',
+  size = 'md',
   leadingIcon,
+  iconOnly,
   block,
   className = '',
   children,
   ...rest
 }: ButtonProps) {
+  const classes = [
+    'kx-btn',
+    `kx-btn--${variant}`,
+    size !== 'md' && `kx-btn--${size}`,
+    iconOnly && 'kx-btn--icon',
+    block && 'kx-btn--block',
+    className,
+  ]
+    .filter(Boolean)
+    .join(' ');
   return (
-    <button
-      className={`kx-btn kx-btn--${variant} ${block ? 'kx-btn--block' : ''} ${className}`}
-      {...rest}
-    >
+    <button className={classes} {...rest}>
       {leadingIcon && <span className="kx-btn__icon" aria-hidden="true">{leadingIcon}</span>}
       {children}
     </button>
diff --git a/src/frontend/src/components/ui/button.css b/src/frontend/src/components/ui/button.css
index 76b44d5..1ea207e 100644
--- a/src/frontend/src/components/ui/button.css
+++ b/src/frontend/src/components/ui/button.css
@@ -20,11 +20,59 @@
   opacity: 0.5;
   cursor: not-allowed;
 }
+.kx-btn:focus-visible {
+  outline: 2px solid var(--focus-ring);
+  outline-offset: 2px;
+}
 .kx-btn__icon {
   display: inline-flex;
   font-size: 18px;
 }
 
+/* ── Nifty 3단 크기 (DESIGN_SYSTEM_NIFTY §2.1) — 기본 md(40) 불변 ── */
+.kx-btn--sm {
+  height: 32px;
+  padding: 0 var(--space-3);
+  font-size: var(--fs-caption);
+  gap: var(--space-1);
+}
+.kx-btn--lg {
+  height: 48px;
+  padding: 0 var(--space-5);
+  font-size: var(--fs-h3);
+}
+
+/* ── 아이콘 전용(정사각) — aria-label 필수 ── */
+.kx-btn--icon {
+  width: 40px;
+  padding: 0;
+}
+.kx-btn--icon.kx-btn--sm {
+  width: 32px;
+}
+.kx-btn--icon.kx-btn--lg {
+  width: 48px;
+}
+
+/* ── 버튼 그룹 — 인접 모서리 접합 ── */
+.kx-btn-group {
+  display: inline-flex;
+}
+.kx-btn-group .kx-btn {
+  border-radius: 0;
+}
+.kx-btn-group .kx-btn:first-child {
+  border-top-left-radius: var(--radius-sm);
+  border-bottom-left-radius: var(--radius-sm);
+}
+.kx-btn-group .kx-btn:last-child {
+  border-top-right-radius: var(--radius-sm);
+  border-bottom-right-radius: var(--radius-sm);
+}
+.kx-btn-group .kx-btn + .kx-btn {
+  margin-left: -1px;
+}
+
 .kx-btn--primary {
   background: var(--color-primary-600);
   color: var(--color-on-accent);
diff --git a/src/frontend/src/screens/boothsales/boothsales.css b/src/frontend/src/screens/boothsales/boothsales.css
index d19fd0d..1e4675e 100644
--- a/src/frontend/src/screens/boothsales/boothsales.css
+++ b/src/frontend/src/screens/boothsales/boothsales.css
@@ -45,7 +45,7 @@
   border-radius: 999px;
   font-size: var(--fs-caption);
   background: var(--kx-surface-2, #f1f5f9);
-  border: 1px solid var(--kx-border, #e2e8f0);
+  border: 1px solid var(--color-neutral-200);
 }
 .kx-bsales__stat strong { font-size: 15px; font-weight: var(--fw-bold); }
 .kx-bsales__stat.is-available { color: #15803d; background: #f0fdf4; border-color: #bbf7d0; }
@@ -81,7 +81,7 @@
   padding: 14px;
   border-radius: 8px;
   background: var(--kx-surface, #fff);
-  border: 1px solid var(--kx-border, #e2e8f0);
+  border: 1px solid var(--color-neutral-200);
   border-left-width: 4px;
 }
 .kx-boothcard.is-available { border-left-color: #22c55e; }
diff --git a/src/frontend/src/screens/cms/cms.css b/src/frontend/src/screens/cms/cms.css
index 39b4326..381d0f1 100644
--- a/src/frontend/src/screens/cms/cms.css
+++ b/src/frontend/src/screens/cms/cms.css
@@ -1151,7 +1151,7 @@
   margin-left: auto;
   font-size: var(--fs-micro);
   color: var(--color-neutral-500);
-  border: 1px dashed var(--color-neutral-300);
+  border: 1px dashed var(--color-neutral-200);
   border-radius: 6px;
   padding: 1px 6px;
   cursor: help;
diff --git a/src/frontend/src/screens/design/studio.css b/src/frontend/src/screens/design/studio.css
index 6243f64..44185c5 100644
--- a/src/frontend/src/screens/design/studio.css
+++ b/src/frontend/src/screens/design/studio.css
@@ -512,7 +512,7 @@
   margin: var(--space-4) var(--space-5) 0;
   padding: var(--space-4);
   background: var(--color-surface, #fff);
-  border: 1px solid var(--color-border, #e5e8ef);
+  border: 1px solid var(--color-neutral-200);
   border-radius: var(--radius-lg);
 }
 .kx-studio__history-head {
diff --git a/src/frontend/src/screens/floorplan/auto-layout.css b/src/frontend/src/screens/floorplan/auto-layout.css
index 761b0f0..ba049f7 100644
--- a/src/frontend/src/screens/floorplan/auto-layout.css
+++ b/src/frontend/src/screens/floorplan/auto-layout.css
@@ -72,7 +72,7 @@
   min-width: 0;
   padding: var(--space-2) var(--space-3);
   font-size: var(--fs-body);
-  border: var(--border-input, 1px solid #d0d5dd);
+  border: 1px solid var(--color-neutral-200);
   border-radius: var(--radius-md);
   color: var(--color-neutral-900);
 }
diff --git a/src/frontend/src/screens/hallassign/hallassign.css b/src/frontend/src/screens/hallassign/hallassign.css
index 264d7e9..d6a9a54 100644
--- a/src/frontend/src/screens/hallassign/hallassign.css
+++ b/src/frontend/src/screens/hallassign/hallassign.css
@@ -86,7 +86,7 @@
   color: var(--color-neutral-700);
 }
 .kx-hall__chip.is-primary {
-  border-color: var(--color-brand-500, #1f29fc);
+  border-color: var(--color-primary-600);
 }
 .kx-hall__chip.is-conflict {
   background: #fef3f2;
@@ -104,7 +104,7 @@
   text-decoration: underline;
 }
 .kx-hall__chipbody:focus-visible {
-  outline: 2px solid var(--color-brand-500, #1f29fc);
+  outline: 2px solid var(--color-primary-600);
   outline-offset: 2px;
 }
 .kx-hall__chiptext {
@@ -303,12 +303,12 @@
   color: var(--color-neutral-700);
 }
 .kx-hall__statusbadge.is-primary {
-  border-color: var(--color-brand-500, #1f29fc);
-  color: var(--color-brand-500, #1f29fc);
+  border-color: var(--color-primary-600);
+  color: var(--color-primary-600);
 }
 .kx-hall__primarytag {
   font-size: var(--fs-caption);
-  color: var(--color-brand-500, #1f29fc);
+  color: var(--color-primary-600);
 }
 .kx-hall__detailsec {
   display: flex;
diff --git a/src/frontend/src/screens/movein/movein.css b/src/frontend/src/screens/movein/movein.css
index aedb1e9..c507cf2 100644
--- a/src/frontend/src/screens/movein/movein.css
+++ b/src/frontend/src/screens/movein/movein.css
@@ -413,7 +413,7 @@
   gap: 10px;
 }
 .kx-logi__item {
-  border: 1px solid var(--color-border, #e4e7ec);
+  border: 1px solid var(--color-neutral-200);
   border-radius: var(--radius-md, 10px);
   padding: 12px 14px;
   background: var(--color-surface, #fff);
@@ -444,7 +444,7 @@
   gap: 8px;
 }
 .kx-logi__act {
-  border: 1px solid var(--color-border, #e4e7ec);
+  border: 1px solid var(--color-neutral-200);
   background: var(--color-surface, #fff);
   border-radius: var(--radius-sm, 8px);
   padding: 6px 12px;
@@ -492,7 +492,7 @@
   width: 10px;
   height: 10px;
   border-radius: 999px;
-  background: var(--color-border, #e4e7ec);
+  background: var(--color-neutral-200);
 }
 .kx-logi__track-dot.is-done {
   background: var(--color-primary, #1f29fc);
diff --git a/src/frontend/src/screens/settlement/settlement.css b/src/frontend/src/screens/settlement/settlement.css
index 5c558e5..91c563a 100644
--- a/src/frontend/src/screens/settlement/settlement.css
+++ b/src/frontend/src/screens/settlement/settlement.css
@@ -426,7 +426,7 @@
 }
 .kx-settle__refund-row--em {
   padding-top: 4px;
-  border-top: 1px dashed var(--color-neutral-300, #d0d5dd);
+  border-top: 1px dashed var(--color-neutral-200);
   font-size: 13px;
 }
 .kx-settle__refund-row--em strong {
diff --git a/src/frontend/src/screens/shared.css b/src/frontend/src/screens/shared.css
index 1ab9303..f521eb7 100644
--- a/src/frontend/src/screens/shared.css
+++ b/src/frontend/src/screens/shared.css
@@ -141,15 +141,151 @@
   box-shadow: 0 1px 2px rgba(16, 24, 40, 0.08);
 }
 
-/* 셀렉트 */
+/* ══════════════════════════════════════════════════════════
+ * 셀렉트 / 드롭다운 — Nifty(§2.4) 계보
+ * 커스텀 캐럿(고정 중립 chevron, 양 테마 공용) + hover/focus/disabled 상태.
+ * appearance:none 로 OS별 기본 화살표 제거 후 kx 캐럿으로 통일.
+ * ══════════════════════════════════════════════════════════ */
 .kx-select {
   height: 36px;
-  padding: 0 var(--space-3);
+  padding: 0 calc(var(--space-5) + 2px) 0 var(--space-3);
+  border: var(--border-card);
+  border-radius: var(--radius-sm);
+  background-color: var(--color-white);
+  color: var(--color-neutral-700);
+  font-size: var(--fs-body);
+  font-family: inherit;
+  line-height: 1;
+  appearance: none;
+  -webkit-appearance: none;
+  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12' fill='none' stroke='%23667085' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M3 4.5 6 7.5 9 4.5'/%3E%3C/svg%3E");
+  background-repeat: no-repeat;
+  background-position: right var(--space-3) center;
+  transition: border-color 0.15s ease, box-shadow 0.15s ease;
+}
+.kx-select:not(:disabled):hover {
+  border-color: var(--color-neutral-500);
+}
+.kx-select:focus-visible {
+  outline: none;
+  border-color: var(--color-primary-600);
+  box-shadow: 0 0 0 3px var(--color-primary-050);
+}
+.kx-select:disabled {
+  opacity: 0.5;
+  cursor: not-allowed;
+  background-color: var(--color-neutral-050);
+}
+.kx-select--sm {
+  height: 32px;
+  font-size: var(--fs-caption);
+}
+
+/* ── 드롭다운 메뉴 (§2.4) — 트리거 + 카드형 메뉴 + 항목. ── */
+.kx-menu {
+  min-width: 180px;
+  padding: var(--space-1);
   border: var(--border-card);
   border-radius: var(--radius-sm);
   background: var(--color-white);
+  box-shadow: var(--shadow-level2);
+}
+.kx-menu__item {
+  display: flex;
+  align-items: center;
+  gap: var(--space-2);
+  width: 100%;
+  padding: var(--space-2) var(--space-3);
+  border: none;
+  border-radius: var(--radius-sm);
+  background: transparent;
   font-size: var(--fs-body);
   color: var(--color-neutral-700);
+  text-align: left;
+  cursor: pointer;
+}
+.kx-menu__item:not(:disabled):hover,
+.kx-menu__item.is-active {
+  background: var(--color-primary-050);
+  color: var(--color-primary-700);
+}
+.kx-menu__item--danger {
+  color: var(--color-error);
+}
+.kx-menu__item--danger:not(:disabled):hover {
+  background: var(--color-error-bg);
+  color: var(--color-error);
+}
+.kx-menu__item:disabled {
+  opacity: 0.5;
+  cursor: not-allowed;
+}
+.kx-menu__divider {
+  height: 1px;
+  margin: var(--space-1) 0;
+  background: var(--color-neutral-200);
+}
+
+/* ══════════════════════════════════════════════════════════
+ * 리스트 그룹 (§2.5) — 공지·활동·검색결과 등 목록형.
+ * 행 = 아이콘/점 + 제목/메타 + 우측 배지/시간. 구분선·hover.
+ * ══════════════════════════════════════════════════════════ */
+.kx-list-group {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+  border: var(--border-card);
+  border-radius: var(--radius-lg);
+  background: var(--color-white);
+  overflow: hidden;
+}
+.kx-list-group__item {
+  display: flex;
+  align-items: center;
+  gap: var(--space-3);
+  padding: var(--space-3) var(--space-4);
+  border-bottom: 1px solid var(--color-neutral-200);
+  font-size: var(--fs-body);
+  color: var(--color-neutral-700);
+}
+.kx-list-group__item:last-child {
+  border-bottom: none;
+}
+a.kx-list-group__item,
+button.kx-list-group__item {
+  width: 100%;
+  border-left: none;
+  border-right: none;
+  border-top: none;
+  background: transparent;
+  text-align: left;
+  cursor: pointer;
+}
+a.kx-list-group__item:hover,
+button.kx-list-group__item:hover,
+.kx-list-group__item.is-active {
+  background: var(--color-primary-050);
+}
+.kx-list-group__item.is-active {
+  color: var(--color-primary-700);
+}
+.kx-list-group__body {
+  flex: 1;
+  min-width: 0;
+}
+.kx-list-group__title {
+  font-weight: var(--fw-semibold);
+  color: var(--color-neutral-900);
+}
+.kx-list-group__meta {
+  font-size: var(--fs-caption);
+  color: var(--color-neutral-500);
+}
+.kx-list-group__aside {
+  margin-left: auto;
+  flex: none;
+  font-size: var(--fs-caption);
+  color: var(--color-neutral-500);
 }
 
 /* KPI 카드(공통) — 카드 정본과 동일 Nifty 엘리베이션 */