diff --git a/src/material/BottomSheet.tsx b/src/material/BottomSheet.tsx
index 130a7a2..1258c81 100644
--- a/src/material/BottomSheet.tsx
+++ b/src/material/BottomSheet.tsx
@@ -11,6 +11,8 @@ import {
 import "./BottomSheet.css";
 import { useHeroSignal } from "../platform/anim";
 import material from "./material.module.css";
+import { ANIM_CURVE_ACELERATION, ANIM_CURVE_DECELERATION } from "./theme";
+import { animateSlideInFromRight, animateSlideOutToRight } from "../platform/anim";
 
 export type BottomSheetProps = {
   open?: boolean;
@@ -39,7 +41,7 @@ function composeAnimationFrame(
   };
 }
 
-const MOVE_SPEED = 1200;
+const MOVE_SPEED = 1600;
 
 const BottomSheet: ParentComponent<BottomSheetProps> = (props) => {
   let element: HTMLDialogElement;
@@ -87,11 +89,16 @@ const BottomSheet: ParentComponent<BottomSheetProps> = (props) => {
         onClose();
         return;
       }
-      const animation = props.bottomUp
+      const onAnimationEnd = () => {
+        element.classList.remove("animated")
+        onClose()
+      }
+      element.classList.add("animated")
+      animation = props.bottomUp
         ? animateSlideInFromBottom(element, true)
-        : animateSlideInFromRight(element, true);
-      animation.addEventListener("finish", onClose);
-      animation.addEventListener("cancel", onClose);
+        : animateSlideOutToRight(element, { easing: ANIM_CURVE_ACELERATION });
+      animation.addEventListener("finish", onAnimationEnd);
+      animation.addEventListener("cancel", onAnimationEnd);
     }
   };
 
@@ -109,37 +116,16 @@ const BottomSheet: ParentComponent<BottomSheetProps> = (props) => {
     } else if (props.bottomUp) {
       animateSlideInFromBottom(element);
     } else if (window.innerWidth <= 560) {
-      animateSlideInFromRight(element);
+      element.classList.add("animated")
+      const onAnimationEnd = () => {
+        element.classList.remove("animated")
+      }
+      animation = animateSlideInFromRight(element, { easing: ANIM_CURVE_DECELERATION });
+      animation.addEventListener("finish", onAnimationEnd)
+      animation.addEventListener("cancel", onAnimationEnd)
     }
   };
 
-  const animateSlideInFromRight = (element: HTMLElement, reserve?: boolean) => {
-    const rect = element.getBoundingClientRect();
-    const easing = "cubic-bezier(0.4, 0, 0.2, 1)";
-    element.classList.add("animated");
-    const oldOverflow = document.body.style.overflow;
-    document.body.style.overflow = "hidden";
-    const distance = Math.abs(rect.left - window.innerWidth);
-    const duration = (distance / MOVE_SPEED) * 1000;
-
-    animation = element.animate(
-      {
-        left: reserve
-          ? [`${rect.left}px`, `${window.innerWidth}px`]
-          : [`${window.innerWidth}px`, `${rect.left}px`],
-      },
-      { easing, duration },
-    );
-    const onAnimationEnd = () => {
-      element.classList.remove("animated");
-      document.body.style.overflow = oldOverflow;
-      animation = undefined;
-    };
-    animation.addEventListener("cancel", onAnimationEnd);
-    animation.addEventListener("finish", onAnimationEnd);
-    return animation;
-  };
-
   const animateSlideInFromBottom = (
     element: HTMLElement,
     reserve?: boolean,
diff --git a/src/platform/anim.ts b/src/platform/anim.ts
index 3dd0ead..3369e09 100644
--- a/src/platform/anim.ts
+++ b/src/platform/anim.ts
@@ -195,3 +195,105 @@ export function animateShrinkToTopRight(
 
   return animation;
 }
+
+// Contribution to the animation speed:
+// - the screen size: mobiles should have longer transition,
+//   the transition time should be longer as the travelling distance longer,
+//   but it's not linear. The larger screen should have higher velocity,
+//   to avoid the transition is too long.
+//   As the screen larger, on desktops, the transition should be simpler and
+//   signficantly faster.
+//   On much smaller screens, like wearables, the transition should be shorter
+//   than on mobiles.
+// - Animation complexity: On mobile:
+//   - large, complex, full-screen transitions may have longer durations, over 375ms
+//   - entering screen over 225ms
+//   - leaving screen over 195ms
+
+function transitionSpeedForEnter(innerWidth: number) {
+  if (innerWidth < 300) {
+    return 2.4;
+  } else if (innerWidth < 560) {
+    return 1.6;
+  } else if (innerWidth < 1200) {
+    return 2.4;
+  } else {
+    return 2.55;
+  }
+}
+
+function transitionSpeedForLeave(innerWidth: number) {
+  if (innerWidth < 300) {
+    return 2.8;
+  } else if (innerWidth < 560) {
+    return 1.96;
+  } else if (innerWidth < 1200) {
+    return 2.8;
+  } else {
+    return 2.55;
+  }
+}
+
+export function animateSlideInFromRight(
+  root: HTMLElement,
+  options?: Omit<KeyframeAnimationOptions, "duration">,
+) {
+  const { left } = root.getBoundingClientRect();
+  const { innerWidth } = window;
+
+  const oldOverflow = document.body.style.overflow;
+  document.body.style.overflow = "hidden";
+
+  const distance = Math.abs(left - innerWidth);
+  const duration = Math.floor(distance / transitionSpeedForEnter(innerWidth));
+
+  const opts = Object.assign({ duration }, options);
+
+  const animation = root.animate(
+    {
+      left: [`${innerWidth}px`, `${left}px`],
+    },
+    opts,
+  );
+
+  const restore = () => {
+    document.body.style.overflow = oldOverflow;
+  };
+
+  animation.addEventListener("cancel", restore);
+  animation.addEventListener("finish", restore);
+
+  return animation;
+}
+
+export function animateSlideOutToRight(
+  root: HTMLElement,
+  options?: Omit<KeyframeAnimationOptions, "duration">,
+) {
+  const { left } = root.getBoundingClientRect();
+  const { innerWidth } = window;
+
+  const oldOverflow = document.body.style.overflow;
+  document.body.style.overflow = "hidden";
+
+  const distance = Math.abs(left - innerWidth);
+  const duration = Math.floor(distance / transitionSpeedForLeave(innerWidth));
+
+  const opts = Object.assign({ duration }, options);
+
+  const animation = root.animate(
+    {
+      left: [`${left}px`, `${innerWidth}px`],
+    },
+    opts,
+  );
+
+  const restore = () => {
+    document.body.style.overflow = oldOverflow;
+  };
+
+  animation.addEventListener("cancel", restore);
+  animation.addEventListener("finish", restore);
+
+  return animation;
+}