fix: 修复错误滚动到底部的问题。删除字数显示，添加toast提示超过字数。输入框扩大按钮移动至左侧。删除侧边栏边框。

src/components/chat/MessageList.vue

@@ -229,7 +229,10 @@ defineExpose({
 });
 
 onMounted(() => {
+  // 只有当有消息时才滚动到底部，否则保持在顶部显示欢迎界面
+  if (visibleMessages.value.length > 0) {
     scrollToBottom(false);
+  }
 });
 </script>
 

src/components/input/ChatInput.vue

@@ -54,6 +54,7 @@
           v-model="inputText"
           :placeholder="placeholder"
           :rows="1"
+          @beforeinput="handleBeforeInput"
           @input="autoResize"
           @focus="isFocused = true"
           @blur="isFocused = false"
@@ -90,6 +91,11 @@
     <!-- 底部工具栏 -->
     <div class="input-toolbar">
       <div class="toolbar-left">
+        <!-- 展开/收起 -->
+        <button class="toolbar-btn" title="展开输入框" @click="toggleExpand">
+          <Maximize2 v-if="!isExpanded" :size="16" />
+          <Minimize2 v-else :size="16" />
+        </button>
         <!-- 深度思考开关 -->
         <button
           class="toolbar-btn"
@@ -126,23 +132,6 @@
           <span>联网搜索</span>
         </button>
 
-        <!-- 展开/收起 -->
-        <button class="toolbar-btn" title="展开输入框" @click="toggleExpand">
-          <Maximize2 v-if="!isExpanded" :size="16" />
-          <Minimize2 v-else :size="16" />
-        </button>
-      </div>
-
-      <div class="toolbar-right">
-        <span
-          class="char-count"
-          :class="{ warning: charCount > maxChars * 0.9 }"
-        >
-          {{ charCount }} / {{ maxChars }}
-        </span>
-        <span class="send-hint">
-          {{ sendOnEnter ? "Enter 发送, Shift+Enter 换行" : "Ctrl+Enter 发送" }}
-        </span>
       </div>
     </div>
   </div>
@@ -190,7 +179,7 @@ const props = withDefaults(
     placeholder: "输入你的问题...",
     isStreaming: false,
     sendOnEnter: false,
-    maxChars: 4000,
+    maxChars: 10,
     disabled: false,
     // 默认全部支持
     supports_thinking: true,
@@ -231,6 +220,18 @@ const textareaRef = ref<HTMLTextAreaElement | null>(null);
 const fileInputRef = ref<HTMLInputElement | null>(null);
 const imageInputRef = ref<HTMLInputElement | null>(null);
 
+// toast 节流
+let lastToastTime = 0;
+const toastThrottleMs = 2000;
+
+function showThrottledToast(message: string, type: 'error'  = 'error') {
+  const now = Date.now();
+  if (now - lastToastTime >= toastThrottleMs) {
+    lastToastTime = now;
+    window.$toast?.(message, type);
+  }
+}
+
 // 计算属性
 const charCount = computed(() => inputText.value.length);
 const isUploading = computed(() => attachments.value.some((a) => a.uploading));
@@ -254,6 +255,27 @@ function autoResize() {
   textarea.style.height = `${Math.min(textarea.scrollHeight, maxHeight)+1}px`;
 }
 
+// 处理输入前事件，限制字数
+function handleBeforeInput(event: InputEvent) {
+  // 如果不是插入文本的操作（如删除、退格等），允许
+  if (!event.data) return;
+
+  // 检查输入后是否会超过限制
+  const currentLength = inputText.value.length;
+  const insertLength = event.data?.length || 0;
+  const selectionStart = (event.target as HTMLTextAreaElement).selectionStart || 0;
+  const selectionEnd = (event.target as HTMLTextAreaElement).selectionEnd || 0;
+  const selectedLength = selectionEnd - selectionStart;
+
+  // 计算输入后的长度
+  const newLength = currentLength - selectedLength + insertLength;
+
+  if (newLength > props.maxChars) {
+    event.preventDefault();
+    showThrottledToast(`已超${props.maxChars}字上限，请删除部分内容`);
+  }
+}
+
 // 处理键盘事件
 function handleKeydown(event: KeyboardEvent) {
   // Ctrl+Enter 或 Cmd+Enter 发送
@@ -298,6 +320,22 @@ async function handlePaste(event: ClipboardEvent) {
   const items = event.clipboardData?.items;
   if (!items) return;
 
+  // 检查粘贴文本是否会超过字数限制
+  const text = event.clipboardData?.getData('text');
+  if (text) {
+    const textarea = event.target as HTMLTextAreaElement;
+    const selectionStart = textarea.selectionStart || 0;
+    const selectionEnd = textarea.selectionEnd || 0;
+    const selectedLength = selectionEnd - selectionStart;
+    const newLength = inputText.value.length - selectedLength + text.length;
+
+    if (newLength > props.maxChars) {
+      event.preventDefault();
+      showThrottledToast(`已超${props.maxChars}字上限，请删除部分内容`);
+      return;
+    }
+  }
+
   for (const item of items) {
     if (item.type.startsWith("image/")) {
       event.preventDefault();
@@ -718,26 +756,6 @@ onMounted(() => {
   }
 }
 
-.toolbar-right {
-  display: flex;
-  align-items: center;
-  gap: 16px;
-}
-
-.char-count {
-  font-size: 12px;
-  color: #9ca3af;
-
-  &.warning {
-    color: #f59e0b;
-  }
-}
-
-.send-hint {
-  font-size: 12px;
-  color: #9ca3af;
-}
-
 @keyframes pulse {
   0%,
   100% {

src/components/sidebar/ChatSidebar.vue

@@ -279,7 +279,6 @@ if (typeof window !== "undefined") {
   position: relative;
   height: 100vh;
   background: #ffffff;
-  border-right: 1px solid #e2e8f0;
   transition: width 0.3s ease;
   overflow: hidden;
   flex-shrink: 0;
@@ -690,8 +689,6 @@ if (typeof window !== "undefined") {
   cursor: col-resize;
   z-index: 10;
 
-  &:hover {
-    background: rgba(59, 130, 246, 0.3);
-  }
+
 }
 </style>