diff --git a/src/app/globals.css b/src/app/globals.css
index a2dc41e..d8a490b 100644
--- a/src/app/globals.css
+++ b/src/app/globals.css
@@ -1,26 +1,264 @@
 @import "tailwindcss";
 
+/* ========================================
+   cchcode UI - 设计令牌
+   基于原型图: https://openclaude.me/chat
+   ======================================== */
+
 :root {
-  --background: #ffffff;
-  --foreground: #171717;
+  /* 品牌色 */
+  --color-primary: #E06B3E;
+  --color-primary-hover: #D4643E;
+  --color-primary-light: #FEF3EF;
+  --color-primary-alpha: rgba(224, 107, 62, 0.1);
+
+  /* 背景色 */
+  --color-bg-primary: #FFFFFF;
+  --color-bg-secondary: #FAFAF9;
+  --color-bg-tertiary: #F7F7F8;
+  --color-bg-hover: #F3F4F6;
+
+  /* 文字色 */
+  --color-text-primary: #111827;
+  --color-text-secondary: #6B7280;
+  --color-text-tertiary: #9CA3AF;
+  --color-text-placeholder: #A0AEC0;
+
+  /* 边框色 */
+  --color-border: #E5E5E5;
+  --color-border-light: #F0F0F0;
+  --color-border-focus: #E06B3E;
+
+  /* 消息气泡色 */
+  --color-message-user: #EDE4DE;
+  --color-message-assistant-bg: #F7F7F6;
+  --color-message-assistant-border: #E8E8E8;
+
+  /* 阴影 */
+  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
+  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
+  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
+  --shadow-dropdown: 0 4px 12px rgba(0, 0, 0, 0.1);
+  --shadow-input: 0 2px 8px rgba(0, 0, 0, 0.04);
+  --shadow-input-focus: 0 4px 16px rgba(224, 107, 62, 0.1);
+
+  /* 布局 */
+  --sidebar-width: 260px;
+  --header-height: 56px;
+  --input-max-width: 900px;
+
+  /* 圆角 */
+  --radius-sm: 6px;
+  --radius-md: 8px;
+  --radius-lg: 12px;
+  --radius-xl: 16px;
+  --radius-2xl: 18px;
+  --radius-full: 9999px;
+
+  /* 过渡 */
+  --transition-fast: 0.15s ease;
+  --transition-base: 0.2s ease;
+  --transition-slow: 0.3s ease;
 }
 
 @theme inline {
-  --color-background: var(--background);
-  --color-foreground: var(--foreground);
-  --font-sans: var(--font-geist-sans);
-  --font-mono: var(--font-geist-mono);
+  /* 品牌色 */
+  --color-primary: var(--color-primary);
+  --color-primary-hover: var(--color-primary-hover);
+  --color-primary-light: var(--color-primary-light);
+
+  /* 背景色 */
+  --color-background: var(--color-bg-secondary);
+  --color-foreground: var(--color-text-primary);
+
+  /* 字体 */
+  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
+  --font-mono: 'SF Mono', Monaco, 'Courier New', monospace;
 }
 
-@media (prefers-color-scheme: dark) {
-  :root {
-    --background: #0a0a0a;
-    --foreground: #ededed;
-  }
+/* ========================================
+   全局样式
+   ======================================== */
+* {
+  box-sizing: border-box;
+}
+
+html {
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
 }
 
 body {
-  background: var(--background);
-  color: var(--foreground);
-  font-family: Arial, Helvetica, sans-serif;
+  background-color: var(--color-bg-secondary);
+  color: var(--color-text-primary);
+  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
+  line-height: 1.5;
+  min-height: 100vh;
+}
+
+/* ========================================
+   自定义滚动条
+   ======================================== */
+::-webkit-scrollbar {
+  width: 6px;
+  height: 6px;
+}
+
+::-webkit-scrollbar-track {
+  background: transparent;
+}
+
+::-webkit-scrollbar-thumb {
+  background-color: var(--color-border);
+  border-radius: var(--radius-full);
+}
+
+::-webkit-scrollbar-thumb:hover {
+  background-color: var(--color-text-tertiary);
+}
+
+/* ========================================
+   动画
+   ======================================== */
+@keyframes fadeIn {
+  from {
+    opacity: 0;
+  }
+  to {
+    opacity: 1;
+  }
+}
+
+@keyframes slideUp {
+  from {
+    opacity: 0;
+    transform: translateY(10px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+@keyframes slideDown {
+  from {
+    opacity: 0;
+    transform: translateY(-8px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.animate-fade-in {
+  animation: fadeIn var(--transition-base);
+}
+
+.animate-slide-up {
+  animation: slideUp var(--transition-base);
+}
+
+.animate-slide-down {
+  animation: slideDown var(--transition-fast);
+}
+
+/* ========================================
+   响应式设计
+   ======================================== */
+@media (max-width: 768px) {
+  :root {
+    --sidebar-width: 0px;
+  }
+}
+
+@media (min-width: 769px) and (max-width: 1024px) {
+  :root {
+    --sidebar-width: 220px;
+  }
+}
+
+/* ========================================
+   按钮样式
+   ======================================== */
+.btn-primary {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  padding: 8px 16px;
+  background-color: var(--color-primary);
+  color: white;
+  font-size: 14px;
+  font-weight: 500;
+  border-radius: var(--radius-md);
+  border: none;
+  cursor: pointer;
+  transition: background-color var(--transition-fast);
+}
+
+.btn-primary:hover {
+  background-color: var(--color-primary-hover);
+}
+
+.btn-ghost {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  padding: 8px 16px;
+  background-color: transparent;
+  color: var(--color-text-secondary);
+  font-size: 14px;
+  font-weight: 500;
+  border-radius: var(--radius-md);
+  border: 1px solid var(--color-border);
+  cursor: pointer;
+  transition: all var(--transition-fast);
+}
+
+.btn-ghost:hover {
+  background-color: var(--color-bg-hover);
+  color: var(--color-text-primary);
+}
+
+.btn-danger {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  padding: 8px 16px;
+  background-color: #DC2626;
+  color: white;
+  font-size: 14px;
+  font-weight: 500;
+  border-radius: var(--radius-md);
+  border: none;
+  cursor: pointer;
+  transition: background-color var(--transition-fast);
+}
+
+.btn-danger:hover {
+  background-color: #B91C1C;
+}
+
+/* ========================================
+   设置页面选择器
+   ======================================== */
+.settings-select {
+  appearance: none;
+  background-color: var(--color-bg-primary);
+  border: 1px solid var(--color-border);
+  border-radius: var(--radius-md);
+  padding: 8px 32px 8px 12px;
+  font-size: 14px;
+  color: var(--color-text-primary);
+  cursor: pointer;
+  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%236B7280' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
+  background-repeat: no-repeat;
+  background-position: right 8px center;
+  min-width: 140px;
+}
+
+.settings-select:focus {
+  outline: none;
+  border-color: var(--color-primary);
+  box-shadow: var(--shadow-input-focus);
 }