feat(viewer): refine visual details to match design reference

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

apps/viewer/src/components/PhotoFeed.vue

@@ -311,23 +311,26 @@ onBeforeUnmount(() => {
   white-space: nowrap;
 }
 
-/* —— 新照片提示 pill：白底蓝字蓝icon，悬浮照片区顶部 —— */
+/* —— 新照片提示 pill（参考稿）：顶部 8px 居中悬浮、白底蓝字、34px 高、
+ *    22px 圆角、轻投影 0 3px 15px —— */
 .new-photo-bar {
   position: sticky;
-  top: 10px;
+  top: 8px;
   z-index: 2;
   display: flex;
   align-items: center;
+  justify-content: center;
   gap: 6px;
   width: fit-content;
+  min-height: 34px;
   margin: 0 auto 12px;
   border: none;
-  border-radius: var(--viewer-radius-pill, 20px);
+  border-radius: var(--viewer-radius-pill, 22px);
   background: var(--viewer-surface, #fff);
-  box-shadow: 0 2px 10px rgba(23, 32, 51, 0.16);
+  box-shadow: 0 3px 15px rgba(23, 32, 51, 0.14);
   color: var(--viewer-primary, #1a73e8);
-  padding: 8px 16px;
-  font-size: 0.8125rem;
+  padding: 0 17px;
+  font-size: 0.75rem;
   font-weight: 600;
   cursor: pointer;
 }
@@ -357,6 +360,18 @@ onBeforeUnmount(() => {
   background: var(--viewer-divider, #e5eaf1);
   cursor: pointer;
 }
+/* 参考稿：底部 40% 高度的轻渐变（transparent → rgba(0,0,0,.25)），
+ * 承托右下角白色点赞角标；不拦截指针（点击仍开大图）。 */
+.cell::after {
+  content: '';
+  position: absolute;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  height: 40%;
+  background: linear-gradient(transparent, rgba(0, 0, 0, 0.25));
+  pointer-events: none;
+}
 .cell-img {
   display: block;
   width: 100%;
@@ -364,32 +379,36 @@ onBeforeUnmount(() => {
   object-fit: cover;
 }
 
-/* —— 点赞角标：右下角半透明暗底（明亮照片上可读），白心 + 白色计数 —— */
+/* —— 点赞角标（参考稿）：右下 3px 贴边、无底色胶囊——白心 19px + 白色计数，
+ *    仅靠 text-shadow 保证明亮照片上的可读性 —— */
 .cell-like {
   position: absolute;
-  right: 6px;
-  bottom: 6px;
+  right: 3px;
+  bottom: 3px;
+  z-index: 1;
   display: inline-flex;
   align-items: center;
   gap: 4px;
   border: none;
-  border-radius: var(--viewer-radius-pill, 20px);
-  background: linear-gradient(to right, rgba(14, 18, 24, 0.42), rgba(14, 18, 24, 0.62));
+  background: transparent;
   color: #fff;
-  padding: 3px 8px;
+  padding: 2px 3px;
   font-size: 0.75rem;
   line-height: 1;
+  text-shadow: 0 1px 4px #222;
   cursor: pointer;
 }
 .cell-like .heart {
-  width: 16px;
-  height: 16px;
+  width: 19px;
+  height: 19px;
   fill: #fff;
+  filter: drop-shadow(0 1px 4px #222);
   animation: heart-pop 400ms ease-out;
 }
 .cell-like .count {
   color: #fff;
   font-variant-numeric: tabular-nums;
+  text-shadow: 0 1px 4px #222;
 }
 @keyframes heart-pop {
   0% {
@@ -459,11 +478,12 @@ onBeforeUnmount(() => {
   text-align: center;
   padding: 8px 0;
 }
+/* 参考稿：到底提示 #96a0b0、12px、24px 16px 收底 */
 .end-note {
   text-align: center;
-  color: var(--viewer-text-secondary, #647084);
-  font-size: 0.875rem;
-  padding: 12px 0;
+  color: #96a0b0;
+  font-size: 0.75rem;
+  padding: 24px 16px;
   margin: 0;
 }
 .sentinel {