feat: 新增5种主题风格 + 风格快速切换按钮

新增主题：
- cherry 樱花粉：甜美可爱
- midnight 午夜：深紫高端
- gold 金色：奢华典雅
- coral 珊瑚：时尚活泼
- mint 薄荷：清新凉爽

UI改进：
- 在图表展示区下方添加15种风格快速切换按钮
- 每个按钮带渐变色预览，点击即切换
- 图表模式和表格模式都支持全部15种主题
- 下拉框和按钮状态双向同步

app.js

@@ -12,7 +12,17 @@ const colorPalettes = {
     dark: ['#4fc3f7', '#81c784', '#fff176', '#ff8a65', '#ba68c8', '#4dd0e1', '#ffab91', '#aed581', '#f48fb1'],
     macarons: ['#2ec7c9', '#b6a2de', '#5ab1ef', '#ffb980', '#d87a80', '#8d98b3', '#e5cf0d', '#97b552', '#95706d'],
     gradient: ['#7f7fd5', '#86a8e7', '#91eae4', '#ff6b6b', '#feca57', '#48dbfb', '#ff9ff3', '#54a0ff', '#5f27cd'],
-    retro: ['#d4a5a5', '#95b9c7', '#f6e8c3', '#dfceb4', '#a4c3b5', '#c9b1ff', '#f5c7b8', '#b8d4e3', '#e8c8a0']
+    retro: ['#d4a5a5', '#95b9c7', '#f6e8c3', '#dfceb4', '#a4c3b5', '#c9b1ff', '#f5c7b8', '#b8d4e3', '#e8c8a0'],
+    ocean: ['#0077b6', '#00b4d8', '#90e0ef', '#caf0f8', '#023e8a', '#48cae4', '#ade8f4', '#0096c7', '#03045e'],
+    forest: ['#2d6a4f', '#40916c', '#52b788', '#74c69d', '#95d5b2', '#b7e4c7', '#d8f3dc', '#1b4332', '#344e41'],
+    sunset: ['#e85d04', '#f48c06', '#faa307', '#ffba08', '#dc2f02', '#d00000', '#9d0208', '#6a040f', '#370617'],
+    lavender: ['#7c3aed', '#8b5cf6', '#a78bfa', '#c4b5fd', '#ddd6fe', '#ede9fe', '#5b21b6', '#4c1d95', '#6d28d9'],
+    minimal: ['#111827', '#374151', '#6b7280', '#9ca3af', '#d1d5db', '#e5e7eb', '#f3f4f6', '#4b5563', '#1f2937'],
+    cherry: ['#e91e63', '#f06292', '#f48fb1', '#f8bbd0', '#fce4ec', '#c2185b', '#ad1457', '#880e4f', '#d81b60'],
+    midnight: ['#6c63ff', '#5a52d5', '#483fb5', '#7c79ff', '#3d3d5c', '#8b89ff', '#9d9bff', '#2c2c4a', '#b3b2ff'],
+    gold: ['#b8860b', '#daa520', '#f0c040', '#ffd700', '#ffe066', '#996515', '#cc9900', '#e6b800', '#8b6914'],
+    coral: ['#ff6f61', '#ff8a70', '#ffa07a', '#ffab91', '#ffccbc', '#e64a19', '#f4511e', '#ff5722', '#d84315'],
+    mint: ['#00bfa5', '#26a69a', '#4db6ac', '#80cbc4', '#b2dfdb', '#00897b', '#00796b', '#004d40', '#009688']
 };
 
 // ===== 示例数据 =====
@@ -718,3 +728,41 @@ function exportTable(format) {
     a.click();
     URL.revokeObjectURL(url);
 }
+
+// ===== 快速切换风格 =====
+function quickSwitchTheme(theme) {
+    // 更新按钮状态
+    document.querySelectorAll('.theme-btn').forEach(btn => {
+        btn.classList.toggle('active', btn.dataset.theme === theme);
+    });
+
+    if (currentMode === 'chart') {
+        // 图表模式：更新主题选择器并重新渲染
+        document.getElementById('themeStyle').value = theme;
+        updateChart();
+    } else {
+        // 表格模式：更新主题选择器并重新请求
+        document.getElementById('tableTheme').value = theme;
+        updateTable();
+    }
+}
+
+// ===== 同步风格按钮状态（下拉框变更时） =====
+function syncThemeButtons(theme) {
+    document.querySelectorAll('.theme-btn').forEach(btn => {
+        btn.classList.toggle('active', btn.dataset.theme === theme);
+    });
+}
+
+// ===== 初始化风格按钮状态 =====
+function initThemeButtons() {
+    // 默认激活 default
+    document.querySelectorAll('.theme-btn').forEach(btn => {
+        btn.classList.toggle('active', btn.dataset.theme === 'default');
+    });
+}
+
+// 页面加载时初始化
+document.addEventListener('DOMContentLoaded', () => {
+    initThemeButtons();
+});