From https://once.com/writebook

app/assets/stylesheets/animation.css

@@ -0,0 +1,69 @@
+/* Animation classes */
+.shake {
+  animation: shake 400ms both;
+}
+
+.wiggle {
+  animation: wiggle 400ms both;
+}
+
+/* Keyframes */
+@keyframes fade-out {
+  to { opacity: 0; }
+}
+
+@keyframes pulse {
+  0%   { opacity: 1; }
+  50%  { opacity: 0.6; }
+  100% { opacity: 1; }
+}
+
+@keyframes shake {
+  0%  { transform: translateX(-2rem); }
+  25% { transform: translateX(2rem); }
+  50% { transform: translateX(-1rem); }
+  75% { transform: translateX(1rem); }
+}
+
+@keyframes submitting {
+  0%    { -webkit-mask-position: 0% 0%,   50% 0%,   100% 0% }
+  12.5% { -webkit-mask-position: 0% 50%,  50% 0%,   100% 0% }
+  25%   { -webkit-mask-position: 0% 100%, 50% 50%,  100% 0% }
+  37.5% { -webkit-mask-position: 0% 100%, 50% 100%, 100% 50% }
+  50%   { -webkit-mask-position: 0% 100%, 50% 100%, 100% 100% }
+  62.5% { -webkit-mask-position: 0% 50%,  50% 100%, 100% 100% }
+  75%   { -webkit-mask-position: 0% 0%,   50% 50%,  100% 100% }
+  87.5% { -webkit-mask-position: 0% 0%,   50% 0%,   100% 50% }
+  100%  { -webkit-mask-position: 0% 0%,   50% 0%,   100% 0% }
+}
+
+@keyframes success {
+  0%  { background-color: var(--color-border-darker); scale: 0.8; }
+  20% { background-color: var(--color-border-darker); scale: 1; }
+}
+
+@keyframes wiggle {
+  0%   { transform: rotate(0deg); }
+  20%  { transform: rotate(3deg); }
+  40%  { transform: rotate(-3deg); }
+  60%  { transform: rotate(3deg); }
+  80%  { transform: rotate(-3deg); }
+  100% { transform: rotate(0deg); }
+}
+
+@keyframes zoom-fade {
+  100% { transform: translateY(-2em); opacity: 0; }
+}
+
+/* View Transitions */
+::view-transition-old(root) {
+  animation:
+    100ms cubic-bezier(0.4, 0, 1, 1) both fade-out,
+    300ms cubic-bezier(0.4, 0, 0.2, 1) both slide-to-left;
+}
+
+::view-transition-new(root) {
+  animation:
+    200ms cubic-bezier(0, 0, 0.2, 1) 90ms both fade-in,
+    300ms cubic-bezier(0.4, 0, 0.2, 1) both slide-from-right;
+}