修复节气计算/佛历倒计时/顶部固定高度+老黄历方框

- 节气改用精确查表(2000-2060天文算法生成)，修复立秋等大偏差
- 佛历倒计时/节日速查以当前选中日期为基准，切换日期实时更新
- 大日历顶部节日区/佛历区固定高度，空着也占位不再跳动
- 大日期加老黄历式方框（双线边框，节假日红/工作日绿）

mini/pages/home/home.js

@@ -82,6 +82,7 @@ Page({
     const almanac = getAlmanacInfo(y, m, d);
     this.setData({ dayInfo, almanac, currentYear: y, currentMonth: m });
     this.refreshDerived();
+    this.loadUpcoming();
   },
 
   /** 计算派生数据（节假日/工作日/佛历/初一十五） */
@@ -92,12 +93,14 @@ Page({
     const workday = isWorkday(y, m, d);
     const termTime = dayInfo.solarTerm ? (SOLAR_TERM_TIMES[dayInfo.solarTerm] || '') : '';
     const isFirstOrFifteen = highlightLunar && (dayInfo.lunarDay === 1 || dayInfo.lunarDay === 15);
-    const nextBuddhist = showBuddhist ? getNextBuddhistFestival() : null;
+    const nextBuddhist = showBuddhist ? getNextBuddhistFestival(y, m, d) : null;
     this.setData({ legalHoliday, workday, termTime, isFirstOrFifteen, nextBuddhist });
   },
 
   loadUpcoming() {
-    this.setData({ upcoming: getUpcomingFestivals(5) });
+    const { dayInfo } = this.data;
+    const { solarYear: y, solarMonth: m, solarDay: d } = dayInfo;
+    this.setData({ upcoming: getUpcomingFestivals(5, y, m, d) });
   },
 
   prevDay() { this.shiftDay(-1); },

mini/pages/home/home.wxml

@@ -27,10 +27,12 @@
         </view>
       </view>
 
-      <!-- 大日期 -->
+      <!-- 大日期（老黄历方框） -->
       <view class="almanac-day-row" catchtap="noop">
         <view class="day-arrow" catchtap="prevDay">‹</view>
-        <view class="almanac-day-num font-chinese {{legalHoliday ? 'num-holiday' : (workday ? 'num-workday' : 'num-weekend')}}">{{dayInfo.solarDay}}</view>
+        <view class="day-frame {{legalHoliday ? 'frame-holiday' : (workday ? 'frame-workday' : 'frame-weekend')}}">
+          <view class="almanac-day-num font-chinese {{legalHoliday ? 'num-holiday' : (workday ? 'num-workday' : 'num-weekend')}}">{{dayInfo.solarDay}}</view>
+        </view>
         <view class="day-arrow" catchtap="nextDay">›</view>
       </view>
 
@@ -40,17 +42,17 @@
         <text class="almanac-lunar-sub">{{dayInfo.lunarYearGanzhi}}年 {{dayInfo.lunarMonthGanzhi}}月 {{dayInfo.lunarDayGanzhi}}日 · 属{{dayInfo.zodiac}}</text>
       </view>
 
-      <!-- 节日/节气/佛历 -->
-      <view class="almanac-fest" wx:if="{{legalHoliday || dayInfo.lunarFestival || dayInfo.solarFestival || dayInfo.solarTerm}}">
+      <!-- 节日/节气（固定高度，空着也占位） -->
+      <view class="almanac-fest">
         <text class="badge badge-holiday" wx:if="{{legalHoliday}}">{{legalHoliday}}</text>
         <text class="badge badge-festival" wx:if="{{dayInfo.lunarFestival && !legalHoliday}}">{{dayInfo.lunarFestival}}</text>
         <text class="badge badge-festival" wx:if="{{dayInfo.solarFestival && !legalHoliday}}">{{dayInfo.solarFestival}}</text>
         <text class="badge badge-term" wx:if="{{dayInfo.solarTerm}}">{{dayInfo.solarTerm}}{{termTime ? ' ' + termTime : ''}}</text>
       </view>
 
-      <!-- 佛历提醒 -->
-      <view class="buddhist-tip" wx:if="{{showBuddhist && nextBuddhist}}" catchtap="noop">
-        <text class="buddhist-text">🪷 距 {{nextBuddhist.name}} 还有 {{nextBuddhist.daysLeft}} 天（{{nextBuddhist.solarDate}}）</text>
+      <!-- 佛历提醒（固定高度，空着也占位） -->
+      <view class="buddhist-tip">
+        <text class="buddhist-text" wx:if="{{showBuddhist && nextBuddhist}}" catchtap="noop">🪷 距 {{nextBuddhist.name}} 还有 {{nextBuddhist.daysLeft}} 天（{{nextBuddhist.solarDate}}）</text>
       </view>
 
       <!-- 工作日/节假日提示 -->

mini/pages/home/home.wxss

@@ -128,13 +128,29 @@
 }
 
 .almanac-day-num {
-  font-size: 240rpx;
+  font-size: 200rpx;
   font-weight: 700;
   line-height: 1.05;
-  min-width: 400rpx;
   text-align: center;
 }
 
+/* 老黄历方框 */
+.day-frame {
+  min-width: 360rpx;
+  height: 300rpx;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  border: 6rpx solid;
+  border-radius: 16rpx;
+  background: #FFFDF8;
+  box-shadow: inset 0 0 0 4rpx #FFFDF8, inset 0 0 0 6rpx currentColor;
+}
+
+.frame-holiday { border-color: #C41E3A; color: #C41E3A; }
+.frame-workday { border-color: #2E7D32; color: #2E7D32; }
+.frame-weekend { border-color: #C41E3A; color: #C41E3A; }
+
 .num-holiday { color: #C41E3A; }
 .num-workday { color: #2E7D32; }
 .num-weekend { color: #C41E3A; }
@@ -165,13 +181,15 @@
   margin-top: 8rpx;
 }
 
-/* 节日 */
+/* 节日（固定高度占位） */
 .almanac-fest {
   display: flex;
   justify-content: center;
+  align-items: center;
   flex-wrap: wrap;
   gap: 12rpx;
   margin-bottom: 12rpx;
+  min-height: 52rpx;
 }
 
 .badge-holiday {
@@ -191,11 +209,15 @@
   color: #FFFFFF;
 }
 
-/* 佛历提醒 */
+/* 佛历提醒（固定高度占位） */
 .buddhist-tip {
   text-align: center;
   padding: 12rpx;
   margin-bottom: 8rpx;
+  min-height: 50rpx;
+  display: flex;
+  align-items: center;
+  justify-content: center;
 }
 
 .buddhist-text {