Add CYD browser flasher with Next.js, i18n, and Web Serial install.

Replace the starter app with a public/local flasher that discovers sibling firmwares, supports en/zh, and documents HTTPS deploy.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/globals.css

@@ -1,26 +1,96 @@
 @import "tailwindcss";
 
 :root {
-  --background: #ffffff;
-  --foreground: #171717;
+  --bg: #12100c;
+  --bg-elev: #1c1812;
+  --ink: #f4efe4;
+  --muted: #9a9080;
+  --line: rgba(244, 239, 228, 0.12);
+  --accent: #f0c50a;
+  --accent-hot: #ffd54a;
+  --accent-ink: #1a1408;
+  --warn: #e8a45a;
+  --background: var(--bg);
+  --foreground: var(--ink);
 }
 
 @theme inline {
   --color-background: var(--background);
   --color-foreground: var(--foreground);
-  --font-sans: var(--font-geist-sans);
-  --font-mono: var(--font-geist-mono);
-}
-
-@media (prefers-color-scheme: dark) {
-  :root {
-    --background: #0a0a0a;
-    --foreground: #ededed;
-  }
+  --font-sans: var(--font-body);
+  --font-display: var(--font-display);
 }
 
 body {
-  background: var(--background);
-  color: var(--foreground);
-  font-family: Arial, Helvetica, sans-serif;
+  background: var(--bg);
+  color: var(--ink);
+  font-family: var(--font-body), "PingFang SC", "Microsoft YaHei", "Noto Sans SC",
+    system-ui, sans-serif;
+  min-height: 100vh;
+}
+
+.bg-grid {
+  position: fixed;
+  inset: 0;
+  z-index: 0;
+  pointer-events: none;
+  background-image:
+    linear-gradient(rgba(240, 197, 10, 0.04) 1px, transparent 1px),
+    linear-gradient(90deg, rgba(240, 197, 10, 0.04) 1px, transparent 1px);
+  background-size: 48px 48px;
+  mask-image: radial-gradient(ellipse 80% 60% at 50% 20%, #000 20%, transparent 75%);
+}
+
+.bg-glow {
+  position: fixed;
+  inset: 0;
+  z-index: 0;
+  pointer-events: none;
+  background:
+    radial-gradient(ellipse 50% 40% at 70% -10%, rgba(240, 197, 10, 0.22), transparent 55%),
+    radial-gradient(ellipse 40% 35% at 10% 80%, rgba(180, 90, 20, 0.12), transparent 50%);
+}
+
+.cta-btn {
+  appearance: none;
+  border: none;
+  font: inherit;
+  font-family: var(--font-display), system-ui, sans-serif;
+  font-weight: 700;
+  letter-spacing: -0.01em;
+  font-size: 1.05rem;
+  padding: 0.85rem 1.5rem;
+  border-radius: 999px;
+  cursor: pointer;
+  color: var(--accent-ink);
+  background: linear-gradient(180deg, var(--accent-hot), var(--accent));
+  box-shadow: 0 8px 24px rgba(240, 197, 10, 0.25);
+  transition: transform 0.15s, filter 0.15s, opacity 0.15s;
+}
+
+.cta-btn:hover:not(:disabled) {
+  filter: brightness(1.05);
+  transform: translateY(-1px);
+}
+
+.cta-btn:disabled {
+  opacity: 0.45;
+  cursor: not-allowed;
+  box-shadow: none;
+  transform: none;
+}
+
+@keyframes rise {
+  from {
+    opacity: 0;
+    transform: translateY(12px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.animate-rise {
+  animation: rise 0.65s ease-out both;
 }