feat: 优化全局样式与组件视觉升级

- 更新 globals.css 全局样式
- 优化 not-found 404 页面
- 升级 footer, mega-dropdown, mobile-tab-bar 布局组件
- 改进 challenge, cta, hero 等核心 section 组件
- 优化 challenge-card, ink-glow-card, product-card 等 UI 组件
- 更新产品常量配置

src/app/globals.css

@@ -158,8 +158,8 @@
   --color-text-primary: #E5E5E5;
   --color-text-secondary: #B0B0B0;
   --color-text-tertiary: #A0A0A0;
-  --color-text-muted: #8C8C8C;
-  --color-text-subtle: #666666;
+  --color-text-muted: #999999;
+  --color-text-subtle: #777777;
   --color-text-placeholder: #737373;
   --color-text-hint: #5C5C5C;
 
@@ -197,10 +197,10 @@
   --color-footer-bg: #000000;
   --color-cta-bg: #141414;
   --color-hero-dark-end: #1A0A10;
-  --color-footer-text: #8C8C8C;
-  --color-footer-text-muted: #525252;
-  --color-footer-text-dim: #737373;
-  --color-footer-text-link: #B0B0B0;
+  --color-footer-text: #999999;
+  --color-footer-text-muted: #6B6B6B;
+  --color-footer-text-dim: #858585;
+  --color-footer-text-link: #C0C0C0;
   --color-footer-border: #262626;
 
   --color-challenge-isolation: rgba(196, 30, 58, 0.12);
@@ -536,7 +536,7 @@ body {
 }
 
 .ink-glow-border {
-  animation: rotateBorder 4s linear infinite;
+  animation: rotateBorder 4s linear infinite paused;
 }
 
 .ink-glow-border::before {
@@ -573,6 +573,10 @@ body {
   opacity: 0.3;
 }
 
+.ink-glow-border:hover {
+  animation-play-state: running;
+}
+
 @media (min-width: 768px) and (max-width: 1023px) {
   .container-wide,
   .container-full {