feat: 添加字体样式工具栏，支持加粗、斜体、颜色、字体、字号调整

css/style.css

@@ -55,6 +55,86 @@ html, body {
     background: #3a7bc8;
 }
 
+/* 文本编辑器工具栏 */
+.text-editor-toolbar {
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    gap: 8px;
+    padding: 10px 16px;
+    background: #fff;
+    border-bottom: 1px solid #e0e0e0;
+    flex-shrink: 0;
+}
+
+.toolbar-btn {
+    width: 40px;
+    height: 40px;
+    font-size: 18px;
+    font-weight: bold;
+    border: 1px solid #ddd;
+    border-radius: 8px;
+    background: #fff;
+    color: #333;
+    cursor: pointer;
+    transition: all 0.2s;
+}
+
+.toolbar-btn:active {
+    background: #f0f0f0;
+}
+
+.toolbar-btn.active {
+    background: #4a90e2;
+    color: #fff;
+    border-color: #4a90e2;
+}
+
+.toolbar-btn.italic {
+    font-style: italic;
+}
+
+.toolbar-divider {
+    width: 1px;
+    height: 28px;
+    background: #ddd;
+    margin: 0 4px;
+}
+
+.toolbar-label {
+    display: flex;
+    align-items: center;
+    gap: 6px;
+    font-size: 13px;
+    color: #666;
+}
+
+.toolbar-label select {
+    padding: 6px 8px;
+    font-size: 13px;
+    border: 1px solid #ddd;
+    border-radius: 6px;
+    background: #fff;
+    cursor: pointer;
+}
+
+#fontSizePicker {
+    min-width: 60px;
+}
+
+#fontPicker {
+    min-width: 55px;
+}
+
+.toolbar-label input[type="color"] {
+    width: 36px;
+    height: 36px;
+    padding: 2px;
+    border: 1px solid #ddd;
+    border-radius: 6px;
+    cursor: pointer;
+}
+
 /* 图片展示区 */
 .canvas-area {
     flex: 1;