修复动画掉帧的问题，增加昼夜切换的过渡动画

themes/Ying/assets/css/main.css

@@ -41,6 +41,32 @@
     --card-shadow-dark: 0 18px 45px rgba(0, 0, 0, 0.9), 0 0 0 1px rgba(148, 163, 184, 0.45);
 }
 
+/* ── Theme switch transition ── */
+::view-transition-old(root),
+::view-transition-new(root) {
+    animation-duration: 0.45s;
+    animation-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
+}
+
+::view-transition-old(root) {
+    animation-name: theme-fade-out;
+}
+
+::view-transition-new(root) {
+    animation-name: theme-fade-in;
+    animation-delay: 0.04s;
+}
+
+@keyframes theme-fade-out {
+    from { opacity: 1; }
+    to   { opacity: 0; }
+}
+
+@keyframes theme-fade-in {
+    from { opacity: 0; }
+    to   { opacity: 1; }
+}
+
 [data-theme="dark"] body {
     color: var(--text-content-dark-color);
     background-color: var(--background-dark-color);
@@ -3736,6 +3762,79 @@ input[type=submit] {
     }
 }
 
+/* ── Toast ── */
+.ying-toast-container {
+    position: fixed;
+    top: 18px;
+    left: 50%;
+    transform: translateX(-50%);
+    z-index: 10000;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 8px;
+    pointer-events: none;
+}
+
+.ying-toast {
+    padding: 9px 18px;
+    border-radius: 6px;
+    font-size: 13px;
+    font-weight: 500;
+    line-height: 1.3;
+    opacity: 0;
+    transform: translateY(-10px);
+    transition: opacity 0.28s ease, transform 0.28s ease;
+    pointer-events: auto;
+    -webkit-backdrop-filter: blur(20px) saturate(180%);
+    backdrop-filter: blur(20px) saturate(180%);
+    will-change: transform, opacity;
+}
+
+.ying-toast--visible {
+    opacity: 1;
+    transform: translateY(0);
+}
+
+.ying-toast--success {
+    background: rgba(34, 197, 94, 0.88);
+    color: #fff;
+    box-shadow: 0 8px 32px rgba(34, 197, 94, 0.18);
+}
+
+.ying-toast--error {
+    background: rgba(239, 68, 68, 0.88);
+    color: #fff;
+    box-shadow: 0 8px 32px rgba(239, 68, 68, 0.18);
+}
+
+.ying-toast--warning {
+    background: rgba(245, 158, 11, 0.88);
+    color: #fff;
+    box-shadow: 0 8px 32px rgba(245, 158, 11, 0.18);
+}
+
+.ying-toast--info {
+    background: rgba(29, 61, 108, 0.85);
+    color: #f0f4fb;
+    box-shadow: 0 8px 32px rgba(29, 61, 108, 0.18);
+}
+
+[data-theme="dark"] .ying-toast--info {
+    background: rgba(159, 196, 244, 0.22);
+    color: #f3f7fd;
+    -webkit-backdrop-filter: blur(24px) saturate(180%);
+    backdrop-filter: blur(24px) saturate(180%);
+}
+
+@media screen and (max-width: 480px) {
+    .ying-toast {
+        padding: 8px 14px;
+        font-size: 12px;
+        border-radius: 5px;
+    }
+}
+
 .floating-tools a {
     width: 40px;
     height: 40px;