feat: 添加深度思考和联网搜索按钮，支持思考内容流式输出和折叠显示

www/style.css

@@ -582,6 +582,102 @@ body {
   font-weight: 600;
 }
 
+/* 功能开关栏 */
+.feature-bar {
+  display: flex;
+  gap: 8px;
+  padding: 8px 16px;
+  background: rgba(255,255,255,0.95);
+  border-top: 1px solid var(--border-color);
+}
+
+.feature-btn {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+  padding: 6px 12px;
+  background: white;
+  border: 1px solid var(--border-color);
+  border-radius: 20px;
+  font-size: 13px;
+  color: var(--text-light);
+  cursor: pointer;
+  transition: all 0.2s;
+}
+
+.feature-btn:hover {
+  border-color: var(--primary);
+  color: var(--primary);
+}
+
+.feature-btn.active {
+  background: linear-gradient(135deg, var(--primary) 0%, #764ba2 100%);
+  border-color: transparent;
+  color: white;
+}
+
+.feature-btn svg {
+  flex-shrink: 0;
+}
+
+/* 思考内容块 */
+.thinking-block {
+  margin-bottom: 12px;
+  background: rgba(102, 126, 234, 0.08);
+  border: 1px solid rgba(102, 126, 234, 0.2);
+  border-radius: 10px;
+  overflow: hidden;
+  cursor: pointer;
+  transition: all 0.2s;
+}
+
+.thinking-block:hover {
+  border-color: rgba(102, 126, 234, 0.4);
+}
+
+.thinking-header {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  padding: 8px 12px;
+  background: rgba(102, 126, 234, 0.12);
+  font-size: 13px;
+  color: var(--primary);
+  font-weight: 500;
+}
+
+.thinking-header svg:first-child {
+  color: var(--primary);
+}
+
+.thinking-arrow {
+  margin-left: auto;
+  transition: transform 0.2s;
+}
+
+.thinking-block.expanded .thinking-arrow {
+  transform: rotate(180deg);
+}
+
+.thinking-content {
+  padding: 0 12px;
+  max-height: 0;
+  overflow: hidden;
+  transition: max-height 0.3s ease, padding 0.3s ease;
+  color: var(--text-light);
+  font-size: 14px;
+  line-height: 1.6;
+}
+
+.thinking-block.expanded .thinking-content {
+  padding: 12px;
+  max-height: 500px;
+}
+
+.thinking-content p {
+  margin: 8px 0;
+}
+
 /* 输入区域 */
 .input-area {
   display: flex;