新增查下月按钮，优化按钮悬停效果

- 新增"查下月"按钮（getCustomMonthRange(-1)）
- 按钮按逻辑排列：查当下 → 查下月 → 查上月 → 查上上月 → 查上上上月
- 按钮 hover 时颜色变亮 + 底部淡白底线，增加 transition 过渡
- 增大 padding 到 14px，按钮间距更舒适

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

main.template.js

@@ -330,13 +330,26 @@
             display: "block",
             lineHeight: "60px",
             height: "60px",
-            padding: "0px 10px",
+            padding: "0px 14px",
             textDecoration: "none",
             color: "#e5e5e5",
             cursor: "pointer",
+            border: "none",
+            borderBottom: "2px solid transparent",
+            transition: "color 0.15s, border-bottom-color 0.15s",
+            outline: "none",
         };
         Object.assign(button.style, copiedStyles);
 
+        button.addEventListener('mouseenter', () => {
+            button.style.color = "#fff";
+            button.style.borderBottomColor = "rgba(255,255,255,0.4)";
+        });
+        button.addEventListener('mouseleave', () => {
+            button.style.color = "#e5e5e5";
+            button.style.borderBottomColor = "transparent";
+        });
+
         // 处理点击事件回调
         if (typeof options.onClick === 'function') {
             button.addEventListener('click', options.onClick);
@@ -413,6 +426,7 @@
     });
     const button4 = createQueryButton('查当周', getCurrentWeekRange);
     const button0 = createQueryButton('查当月', () => getCustomMonthRange(0));
+    const buttonNext = createQueryButton('查下月', () => getCustomMonthRange(-1));
     const button1 = createQueryButton('查上月', () => getCustomMonthRange(1));
     const button2 = createQueryButton('查上上月', () => getCustomMonthRange(2));
     const button3 = createQueryButton('查上上上月', () => getCustomMonthRange(3));
@@ -425,6 +439,7 @@
     container.appendChild(button);
     container.appendChild(button4);
     container.appendChild(button0);
+    container.appendChild(buttonNext);
     container.appendChild(button1);
     container.appendChild(button2);
     container.appendChild(button3);