优化多个页面样式及组件功能，优化课程、发现、训练、首页等核心页面样式

gym-manage-uniapp/pages/train/index.vue

@@ -53,7 +53,7 @@ function goCheckIn() {
 <style lang="scss" scoped>
 .tab-page {
   min-height: 100vh;
-  background-color: #f0f4f8;
+  background: $gradient-sky;
   padding-bottom: 160rpx;
 }
 
@@ -64,15 +64,15 @@ function goCheckIn() {
 .tab-page__title {
   display: block;
   font-size: 40rpx;
-  font-weight: 700;
-  color: #1a202c;
+  font-weight: $font-weight-bold;
+  color: $text-dark;
 }
 
 .tab-page__subtitle {
   display: block;
   margin-top: 8rpx;
   font-size: 24rpx;
-  color: #64748b;
+  color: $text-muted;
 }
 
 .train-cards {
@@ -84,23 +84,29 @@ function goCheckIn() {
 
 .train-card {
   padding: 28rpx 32rpx;
-  border-radius: 24rpx;
-  background: #fff;
-  box-shadow: 0 2rpx 12rpx rgba(0, 0, 0, 0.06);
+  border-radius: $radius-md;
+  background: $bg-white;
+  box-shadow: $shadow-sm;
+  border: 1px solid $border-light;
+  transition: all 0.2s ease;
+}
+
+.train-card:active {
+  transform: scale(0.98);
 }
 
 .train-card__title {
   display: block;
   font-size: 30rpx;
-  font-weight: 700;
-  color: #1e2a3a;
+  font-weight: $font-weight-bold;
+  color: $text-dark;
 }
 
 .train-card__desc {
   display: block;
   margin-top: 8rpx;
   font-size: 24rpx;
-  color: #64748b;
+  color: $text-muted;
 }
 
 .bottom-placeholder {