feat(splash): simplify multi-character home layout

src/app/splash/components/splash-screen.module.css

@@ -8,16 +8,13 @@
   overflow: hidden;
 }
 
-/* 渐变：accent (bottom-left) → transparent (center-right) */
-.gradientOverlay {
+.imageScrim {
   position: absolute;
   inset: 0;
-  background: linear-gradient(
-    to top right,
-    var(--color-accent),
-    transparent 60%
-  );
-  opacity: 0.5;
+  background: rgba(25, 17, 23, 0.08);
+  box-shadow:
+    inset 0 -290px 150px -145px rgba(20, 12, 18, 0.78),
+    inset 0 110px 90px -90px rgba(11, 8, 10, 0.42);
   z-index: 1;
   pointer-events: none;
 }
@@ -49,15 +46,9 @@
   flex: 1 1 auto;
 }
 
-.buttonArea {
-  margin-top: var(--page-section-gap-lg, 26px);
-}
-
-.bottom {
-  margin: var(--page-section-gap-lg, 32px) 0 0 0;
-  font-size: var(--responsive-body, var(--font-size-md));
-  font-weight: 400;
-  line-height: 1.5;
-  color: rgba(255, 255, 255, 0.9);
-  text-align: left;
+.bottomStack {
+  display: flex;
+  flex-direction: column;
+  gap: clamp(12px, 3.6vw, 18px);
+  padding-bottom: clamp(12px, 3.6vw, 18px);
 }