6 changed files with 48 additions and 155 deletions
--- a/src/app/chat/[id]/page.tsx
+++ b/src/app/chat/[id]/page.tsx
@ -490,7 +490,7 @@ export default function ChatPage({ params }: PageProps) {

        {/* 固定底部输入框 */}
        <div
-          className="sticky bottom-0 pt-4 z-20"
+          className="sticky bottom-0 pt-4"
          style={{
            background: `linear-gradient(to top, var(--color-bg-secondary) 0%, var(--color-bg-secondary) 80%, transparent 100%)`
          }}
--- a/src/components/features/ChatInput.tsx
+++ b/src/components/features/ChatInput.tsx
@ -127,7 +127,7 @@ export function ChatInput({
            onKeyDown={handleKeyDown}
            onPaste={handlePaste}
            placeholder={files.length > 0 ? '添加描述（可选）...' : placeholder}
-            className="w-full border-none outline-none text-[var(--color-text-primary)] bg-transparent py-2 placeholder:text-[var(--color-text-placeholder)]"
+            className="w-full border-none outline-none text-base text-[var(--color-text-primary)] bg-transparent py-2 placeholder:text-[var(--color-text-placeholder)]"
          />
        </div>

--- a/src/components/features/MessageBubble.tsx
+++ b/src/components/features/MessageBubble.tsx
@ -152,7 +152,7 @@ export function MessageBubble({ message, user, thinkingContent, isStreaming, err
              })}
            </div>
          )}
-          <div className="bg-[var(--color-message-user)] text-[var(--color-text-primary)] px-4 py-3 rounded-md leading-relaxed">
+          <div className="bg-[var(--color-message-user)] text-[var(--color-text-primary)] px-4 py-3 rounded-md text-base leading-relaxed">
            {message.content || ((uploadedImages && uploadedImages.length > 0) || (uploadedDocuments && uploadedDocuments.length > 0) ? '(附件)' : '')}
          </div>
          {/* 悬停显示复制按钮 */}
@ -216,7 +216,7 @@ export function MessageBubble({ message, user, thinkingContent, isStreaming, err
            </button>
            {thinkingExpanded && (
              <div className="mt-2 p-4 bg-purple-50 border border-purple-200 rounded-lg">
-                <pre className="text-purple-800 whitespace-pre-wrap font-mono">
+                <pre className="text-sm text-purple-800 whitespace-pre-wrap font-mono">
                  {thinkingContent}
                </pre>
              </div>
@ -228,13 +228,13 @@ export function MessageBubble({ message, user, thinkingContent, isStreaming, err
        {error && (
          <div className="mb-3 p-4 bg-red-50 border border-red-200 rounded-lg flex items-start gap-3">
            <AlertCircle size={20} className="text-red-500 flex-shrink-0 mt-0.5" />
-            <div className="text-red-700">{error}</div>
+            <div className="text-sm text-red-700">{error}</div>
          </div>
        )}

        {/* 主要内容 */}
        <div className="bg-[var(--color-message-assistant-bg)] border border-[var(--color-message-assistant-border)] rounded-md px-5 py-4 shadow-sm">
-          <div className="text-[var(--color-text-primary)] leading-[1.75]">
+          <div className="text-sm text-[var(--color-text-primary)] leading-[1.75]">
            {message.content ? (
              <MarkdownRenderer content={message.content} />
            ) : isStreaming ? (
--- a/src/components/markdown/CodeBlock.tsx
+++ b/src/components/markdown/CodeBlock.tsx
@ -1,7 +1,7 @@
 'use client';

 import { useEffect, useRef, useState, useMemo } from 'react';
-import { Copy, Check, Eye, ChevronDown, ChevronUp } from 'lucide-react';
+import { Copy, Check, Eye } from 'lucide-react';
 import { cn } from '@/lib/utils';
 import Prism from 'prismjs';
 import { HtmlPreviewModal } from '@/components/ui/HtmlPreviewModal';
@ -30,10 +30,6 @@ interface CodeBlockProps {
  language?: string;
  showLineNumbers?: boolean;
  className?: string;
-  /** 折叠阈值，超过此行数自动折叠，默认 60 */
-  maxCollapsedLines?: number;
-  /** 折叠时预览的行数，默认 30 */
-  previewLines?: number;
 }

 // 语言别名映射
@ -55,12 +51,9 @@ export function CodeBlock({
  language = 'text',
  showLineNumbers = true,
  className,
-  maxCollapsedLines = 60,
-  previewLines = 30,
 }: CodeBlockProps) {
  const [copied, setCopied] = useState(false);
  const [previewOpen, setPreviewOpen] = useState(false);
-  const [isExpanded, setIsExpanded] = useState(false);

  // 规范化语言名称
  const normalizedLanguage = languageAliases[language.toLowerCase()] || language.toLowerCase();
@ -69,33 +62,17 @@ export function CodeBlock({
  const isHtmlPreviewable = ['html', 'htm', 'markup'].includes(normalizedLanguage) ||
                            ['html', 'htm'].includes(language.toLowerCase());

-  const lines = code.split('\n');
-  const totalLines = lines.length;
-  const shouldCollapse = totalLines > maxCollapsedLines;
-  const remainingLines = totalLines - previewLines;
-
-  // 根据折叠状态获取显示的代码
-  const displayCode = useMemo(() => {
-    if (shouldCollapse && !isExpanded) {
-      return lines.slice(0, previewLines).join('\n');
-    }
-    return code;
-  }, [code, lines, shouldCollapse, isExpanded, previewLines]);
-
-  const displayLines = displayCode.split('\n');
-
  // 使用 useMemo 缓存高亮后的 HTML，避免频繁重新高亮
  const highlightedCode = useMemo(() => {
    const grammar = Prism.languages[normalizedLanguage];
    if (grammar) {
-      return Prism.highlight(displayCode, grammar, normalizedLanguage);
+      return Prism.highlight(code, grammar, normalizedLanguage);
    }
-    return displayCode;
-  }, [displayCode, normalizedLanguage]);
+    return code;
+  }, [code, normalizedLanguage]);

  const handleCopy = async () => {
    try {
-      // 始终复制完整代码
      await navigator.clipboard.writeText(code);
      setCopied(true);
      setTimeout(() => setCopied(false), 2000);
@ -104,15 +81,13 @@ export function CodeBlock({
    }
  };

-  const toggleExpand = () => {
-    setIsExpanded(!isExpanded);
-  };
+  const lines = code.split('\n');

  return (
    <div className={cn('relative group rounded overflow-hidden my-4', className)}
         style={{ boxShadow: 'var(--color-code-shadow)' }}>
      {/* 顶部工具栏 */}
-      <div className="flex items-center justify-between px-4 py-2.5 text-[0.9em]"
+      <div className="flex items-center justify-between px-4 py-2.5 text-sm"
           style={{
             backgroundColor: 'var(--color-code-toolbar-bg)',
             color: 'var(--color-code-toolbar-text)',
@ -131,12 +106,6 @@ export function CodeBlock({
                  style={{ backgroundColor: '#27c93f', boxShadow: '0 0 0 1px rgba(0, 0, 0, 0.1) inset' }} />
          </div>
          <span className="font-mono text-[13px]">{language || 'code'}</span>
-          {/* 显示总行数 */}
-          {shouldCollapse && (
-            <span className="text-[12px] opacity-60">
-              ({totalLines} 行)
-            </span>
-          )}
        </div>

        {/* 右侧：操作按钮 */}
@ -176,93 +145,40 @@ export function CodeBlock({
      </div>

      {/* 代码区域 */}
-      <div style={{ backgroundColor: 'var(--color-code-bg)' }}>
-        {/* 代码内容 - 使用 flex 布局 */}
-        <div className="flex overflow-x-auto">
-          {/* 行号列 */}
-          {showLineNumbers && (
-            <div
-              className="flex-shrink-0 w-12 select-none py-4 px-2 text-right"
-              style={{
-                backgroundColor: 'var(--color-code-bg)',
-                borderRight: '1px solid var(--color-code-line-border)'
-              }}
-            >
-              {displayLines.map((_, index) => (
+      <div className="relative overflow-x-auto"
+           style={{ backgroundColor: 'var(--color-code-bg)' }}>
+        {showLineNumbers && (
+          <div className="absolute left-0 top-0 bottom-0 w-12 select-none"
+               style={{
+                 backgroundColor: 'var(--color-code-bg)',
+                 borderRight: '1px solid var(--color-code-line-border)'
+               }}>
+            <div className="py-4 px-2 text-right">
+              {lines.map((_, index) => (
                <div
                  key={index}
-                  className="font-mono leading-6"
+                  className="text-sm font-mono leading-6"
                  style={{ color: 'var(--color-code-line-number)' }}
                >
                  {index + 1}
                </div>
              ))}
            </div>
-          )}
-          {/* 代码列 */}
-          <pre
-            className="flex-1 p-4 overflow-x-auto"
-            style={{ margin: 0, background: 'transparent' }}
-          >
-            <code
-              className={`language-${normalizedLanguage} leading-6`}
-              style={{ color: 'var(--color-code-text)' }}
-              dangerouslySetInnerHTML={{ __html: highlightedCode }}
-            />
-          </pre>
-        </div>
-
-        {/* 渐变遮罩和展开按钮（仅在折叠状态下显示） */}
-        {shouldCollapse && !isExpanded && (
-          <>
-            {/* 渐变遮罩 */}
-            <div
-              className="h-16 -mt-16 pointer-events-none relative z-10"
-              style={{
-                background: `linear-gradient(to bottom, transparent, var(--color-code-bg))`
-              }}
-            />
-            {/* 展开按钮 */}
-            <div
-              className="py-3 text-center cursor-pointer transition-colors hover:opacity-80"
-              style={{ backgroundColor: 'var(--color-code-bg)' }}
-              onClick={toggleExpand}
-            >
-              <button
-                className="inline-flex items-center gap-2 px-4 py-2 rounded-lg text-[0.9em] font-medium transition-colors"
-                style={{
-                  color: 'var(--color-primary)',
-                  backgroundColor: 'var(--color-primary-alpha)'
-                }}
-              >
-                <ChevronDown size={16} />
-                <span>展开剩余 {remainingLines} 行代码</span>
-              </button>
-            </div>
-          </>
-        )}
-
-        {/* 收起按钮（仅在展开状态下显示） */}
-        {shouldCollapse && isExpanded && (
-          <div
-            className="py-3 text-center cursor-pointer transition-colors"
-            style={{
-              backgroundColor: 'var(--color-code-bg)',
-              borderTop: '1px solid var(--color-code-line-border)'
-            }}
-            onClick={toggleExpand}
-          >
-            <button
-              className="inline-flex items-center gap-2 px-4 py-2 rounded-lg text-[0.9em] font-medium transition-colors"
-              style={{
-                color: 'var(--color-code-toolbar-text)'
-              }}
-            >
-              <ChevronUp size={16} />
-              <span>收起代码</span>
-            </button>
          </div>
        )}
+        <pre
+          className={cn(
+            'p-4 overflow-x-auto',
+            showLineNumbers && 'pl-16'
+          )}
+          style={{ margin: 0, background: 'transparent' }}
+        >
+          <code
+            className={`language-${normalizedLanguage} text-sm leading-6`}
+            style={{ color: 'var(--color-code-text)' }}
+            dangerouslySetInnerHTML={{ __html: highlightedCode }}
+          />
+        </pre>
      </div>

      {/* HTML 预览模态框 */}
--- a/src/components/markdown/MarkdownRenderer.tsx
+++ b/src/components/markdown/MarkdownRenderer.tsx
@ -48,31 +48,31 @@ const markdownComponents = {
    );
  },

-  // 标题 - 使用相对单位保持与全局字体的比例
+  // 标题
  h1({ children }: { children?: React.ReactNode }) {
    return (
-      <h1 className="text-[1.25em] font-bold mt-5 mb-3 text-[var(--color-text-primary)]">
+      <h1 className="text-lg font-bold mt-5 mb-3 text-[var(--color-text-primary)]">
        {children}
      </h1>
    );
  },
  h2({ children }: { children?: React.ReactNode }) {
    return (
-      <h2 className="text-[1.125em] font-bold mt-4 mb-2 text-[var(--color-text-primary)]">
+      <h2 className="text-base font-bold mt-4 mb-2 text-[var(--color-text-primary)]">
        {children}
      </h2>
    );
  },
  h3({ children }: { children?: React.ReactNode }) {
    return (
-      <h3 className="text-[1em] font-semibold mt-3 mb-2 text-[var(--color-text-primary)]">
+      <h3 className="text-sm font-semibold mt-3 mb-2 text-[var(--color-text-primary)]">
        {children}
      </h3>
    );
  },
  h4({ children }: { children?: React.ReactNode }) {
    return (
-      <h4 className="text-[1em] font-semibold mt-2 mb-1 text-[var(--color-text-primary)]">
+      <h4 className="text-sm font-semibold mt-2 mb-1 text-[var(--color-text-primary)]">
        {children}
      </h4>
    );
@ -95,7 +95,7 @@ const markdownComponents = {
  },
  li({ children }: { children?: React.ReactNode }) {
    return (
-      <li className="leading-relaxed">
+      <li className="leading-relaxed text-sm">
        {children}
      </li>
    );
@ -136,7 +136,7 @@ const markdownComponents = {
  // 引用
  blockquote({ children }: { children?: React.ReactNode }) {
    return (
-      <blockquote className="border-l-3 border-[var(--color-primary)] pl-3 my-3 italic text-[var(--color-text-secondary)]">
+      <blockquote className="border-l-3 border-[var(--color-primary)] pl-3 my-3 italic text-sm text-[var(--color-text-secondary)]">
        {children}
      </blockquote>
    );
@ -153,7 +153,7 @@ const markdownComponents = {
  table({ children }: { children?: React.ReactNode }) {
    return (
      <div className="overflow-x-auto my-3">
-        <table className="min-w-full border border-[var(--color-border)] rounded-lg overflow-hidden text-[0.9em]">
+        <table className="min-w-full border border-[var(--color-border)] rounded-lg overflow-hidden text-sm">
          {children}
        </table>
      </div>
@ -182,14 +182,14 @@ const markdownComponents = {
  },
  th({ children }: { children?: React.ReactNode }) {
    return (
-      <th className="px-3 py-1.5 text-left text-[0.85em] font-semibold text-[var(--color-text-primary)]">
+      <th className="px-3 py-1.5 text-left text-xs font-semibold text-[var(--color-text-primary)]">
        {children}
      </th>
    );
  },
  td({ children }: { children?: React.ReactNode }) {
    return (
-      <td className="px-3 py-1.5 text-[0.85em] text-[var(--color-text-secondary)]">
+      <td className="px-3 py-1.5 text-xs text-[var(--color-text-secondary)]">
        {children}
      </td>
    );
--- a/src/components/ui/HtmlPreviewModal.tsx
+++ b/src/components/ui/HtmlPreviewModal.tsx
@ -1,6 +1,6 @@
 'use client';

-import { useState, useCallback, useEffect, useRef, useMemo } from 'react';
+import { useState, useCallback, useEffect, useRef } from 'react';
 import {
  X,
  Monitor,
@ -83,29 +83,6 @@ export function HtmlPreviewModal({
  // 获取当前设备配置
  const currentDevice = deviceConfigs.find((d) => d.type === device) || deviceConfigs[0];

-  // 处理 HTML 代码，注入 <base target="_blank"> 防止链接影响父窗口
-  const processedHtmlCode = useMemo(() => {
-    const baseTag = '<base target="_blank">';
-
-    // 检查是否已经有 <base> 标签
-    if (/<base\s/i.test(htmlCode)) {
-      return htmlCode;
-    }
-
-    // 尝试在 <head> 标签后注入
-    if (/<head[^>]*>/i.test(htmlCode)) {
-      return htmlCode.replace(/<head[^>]*>/i, `$&\n    ${baseTag}`);
-    }
-
-    // 尝试在 <html> 标签后注入
-    if (/<html[^>]*>/i.test(htmlCode)) {
-      return htmlCode.replace(/<html[^>]*>/i, `$&\n  <head>\n    ${baseTag}\n  </head>`);
-    }
-
-    // 如果都没有，在最前面添加
-    return `<head>${baseTag}</head>\n${htmlCode}`;
-  }, [htmlCode]);
-
  // ESC 关闭 / F11 全屏切换
  useEffect(() => {
    if (!isOpen) return;
@ -371,7 +348,7 @@ export function HtmlPreviewModal({
                {/* iframe 预览 */}
                <iframe
                  key={iframeKey}
-                  srcDoc={processedHtmlCode}
+                  srcDoc={htmlCode}
                  sandbox="allow-scripts allow-same-origin"
                  className="w-full bg-white"
                  style={{