feat(frontend): replace lazy loading with zibll lazysizes

assets/css/frontend/enhancements/modal-motion/dark-mode-2.css

@@ -69,53 +69,34 @@
     }
 }
 
-/* ============================================================
- * 14. 图片懒加载 blur-to-sharp 过渡
- * 模仿 zibll 的 lazy_blur 效果
- * ============================================================ */
-img.lazyload,
-img.lazyloaded,
-img[data-src] {
-    transition: filter 0.6s var(--ease), opacity 0.4s var(--ease);
+/* Zibll lazySizes state and animation contract. */
+.lazyloaded {
+    transition: 0.3s;
+    --lazy-animation: lazy_blur;
 }
 
-img.lazyload,
-img[data-src] {
-    filter: blur(5px);
-    opacity: 0.7;
+.lazyloaded.img-icon {
+    --lazy-animation: lazy_fade;
 }
 
-img.lazyloaded {
-    filter: blur(0);
-    opacity: 1;
+img.lazyloaded:not(.lazyloadafter) {
+    -webkit-animation: var(--lazy-animation) 0.6s;
+    animation: var(--lazy-animation) 0.6s;
 }
 
-/* 14b. aksrt-lazy 动画变体（按 lazyload_animation 配置切换） */
-@keyframes aksrt-lazy-blur {
-    from { filter: blur(8px); opacity: 0.6; }
-    to   { filter: blur(0); opacity: 1; }
-}
-@keyframes aksrt-lazy-fade {
-    from { opacity: 0; }
-    to   { opacity: 1; }
-}
-@keyframes aksrt-lazy-scale {
-    from { transform: scale(1.08); opacity: 0.8; }
-    to   { transform: scale(1); opacity: 1; }
+@keyframes lazy_blur {
+    0% { filter: blur(5px); }
+    100% { filter: blur(0); }
 }
 
-img.aksrt-lazy {
-    transition: filter 0.5s var(--ease), opacity 0.5s var(--ease), transform 0.5s var(--ease);
+@keyframes lazy_fade {
+    0% { opacity: 0; }
+    100% { opacity: 1; }
 }
 
-img.aksrt-loaded[data-lazy-animation="blur"] {
-    animation: aksrt-lazy-blur 0.6s ease both;
-}
-img.aksrt-loaded[data-lazy-animation="fade"] {
-    animation: aksrt-lazy-fade 0.6s ease both;
-}
-img.aksrt-loaded[data-lazy-animation="scale"] {
-    animation: aksrt-lazy-scale 0.5s ease both;
+@keyframes lazy_scale {
+    0% { transform: scale(1.1); }
+    80% { transform: unset; }
 }
 
 /* ============================================================
@@ -308,21 +289,6 @@ input:focus, textarea:focus, select:focus,
     animation: aksrtPopIn var(--dur-fast) var(--ease-out) forwards;
 }
 
-/* --- 图片懒加载过渡 --- */
-img.lazyload, img.lazyloaded, img[data-src] {
-    transition: filter 0.6s var(--ease), opacity 0.4s var(--ease);
-}
-
-img.lazyload, img[data-src] {
-    filter: blur(5px);
-    opacity: 0.7;
-}
-
-img.lazyloaded {
-    filter: blur(0);
-    opacity: 1;
-}
-
 /* --- 滚动进度条动效 --- */
 .reading-progress-bar {
     transition: width 0.1s linear;