feat: 完成全站深色主题改造

Yi.Ai.Vue3/src/components/SystemAnnouncementDialog/index.vue

@@ -444,7 +444,7 @@ watch(isDialogVisible, async (newValue) => {
   :deep(.el-tabs__header) {
     flex-shrink: 0;
     margin: 0 20px;
-    padding-top: 16px;
+    //padding-top: 16px;
     background-color: #f8f9fa;
   }
 
@@ -518,7 +518,7 @@ watch(isDialogVisible, async (newValue) => {
   .activity-list {
     display: flex;
     flex-direction: column;
-    gap: 20px;
+    gap: 12px;
   }
 
   .activity-item {
@@ -923,11 +923,11 @@ watch(isDialogVisible, async (newValue) => {
 
   .announcement-item {
     position: relative;
-    padding: 24px;
+    padding: 20px;
     background: #fff;
     border-radius: 12px;
     overflow: hidden;
-    margin-bottom: 16px;
+    margin-bottom: 10px;
     transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
     box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
     border: 1px solid #e8e9eb;

Yi.Ai.Vue3/src/components/userPersonalCenter/components/UsageStatistics.vue

@@ -1166,7 +1166,7 @@ onBeforeUnmount(() => {
     <el-card v-loading="loading" class="chart-card today-model-card">
       <template #header>
         <div class="card-header">
-          <span class="card-title">📋 今日各模型使用量统计</span>
+          <span class="card-title">📋 今日各模型使用量统计(凌晨零点至现在)</span>
           <el-tag v-if="todayModelUsageData.length > 0" type="success" effect="plain">
             共 {{ todayModelUsageData.length }} 个模型
           </el-tag>
@@ -1469,7 +1469,7 @@ onBeforeUnmount(() => {
 
 .model-cards-grid {
   display: grid;
-  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
+  grid-template-columns: repeat(4, 1fr);
   gap: 14px;
 }