feat(website): 三轮视觉改造与页面过渡动画

改造概要（30项）：
- 第一轮：Hero重构/Section差异化/SocialProof强化/CTA对比度/About架构
- 第二轮：字体优化/背景交替/Solutions差异化/Footer五列/MegaDropdown修复
- 第三轮：卡片交互/表单层级/CTA统一/时间线标记/连接线/三列布局/移动导航/Button微交互/SEO Schema
- P3-2：template.tsx+Framer Motion页面过渡/loading.tsx加载状态
- 清理：删除未用组件/hooks，修复重复移动导航，清理冗余CSS

src/components/ui/button.tsx

@@ -7,22 +7,22 @@ import { cva, type VariantProps } from "class-variance-authority"
 import { cn } from "@/lib/utils"
 
 const buttonVariants = cva(
-  "inline-flex items-center justify-center gap-2 whitespace-nowrap rounded-lg text-sm font-medium transition-all duration-200 disabled:pointer-events-none disabled:opacity-50 [&_svg]:pointer-events-none [&_svg:not([class*='size-'])]:size-4 shrink-0 [&_svg]:shrink-0 outline-none focus-visible:ring-2 focus-visible:ring-[#1C1C1C] focus-visible:ring-offset-2 focus-visible:ring-offset-white min-h-[44px] min-w-[44px] touch-manipulation",
+  "inline-flex items-center justify-center gap-2 whitespace-nowrap rounded-lg text-sm font-medium transition-all duration-200 disabled:pointer-events-none disabled:opacity-50 [&_svg]:pointer-events-none [&_svg:not([class*='size-'])]:size-4 shrink-0 [&_svg]:shrink-0 outline-none focus-visible:ring-2 focus-visible:ring-[var(--color-primary)] focus-visible:ring-offset-2 focus-visible:ring-offset-white min-h-[44px] min-w-[44px] touch-manipulation",
   {
     variants: {
       variant: {
         default:
-          "bg-[#C41E3A] text-white hover:bg-[#A01830] hover:shadow-[0_4px_12px_rgba(196,30,58,0.25)] hover:-translate-y-0.5 active:scale-[0.98]",
+          "bg-[var(--color-brand-primary)] text-white hover:bg-[var(--color-brand-primary-hover)] hover:shadow-[0_4px_12px_rgba(var(--color-brand-primary-rgb),0.25)] hover:-translate-y-0.5 active:scale-[0.98]",
         secondary:
-          "bg-[#1C1C1C] text-white hover:bg-[#0A0A0A] hover:shadow-[0_4px_12px_rgba(28,28,28,0.25)] hover:-translate-y-0.5 active:scale-[0.98]",
+          "bg-[var(--color-primary)] text-white hover:bg-[var(--color-primary-hover)] hover:shadow-[0_4px_12px_rgba(var(--color-primary-rgb),0.25)] hover:-translate-y-0.5 active:scale-[0.98]",
         destructive:
-          "bg-[#C41E3A] text-white hover:bg-[#A01830] focus-visible:ring-[#C41E3A]",
+          "bg-[var(--color-brand-primary)] text-white hover:bg-[var(--color-brand-primary-hover)] focus-visible:ring-[var(--color-brand-primary)]",
         outline:
-          "border-2 border-[#1C1C1C] bg-transparent text-[#1C1C1C]",
+          "border-2 border-[var(--color-primary)] bg-transparent text-[var(--color-primary)] hover:bg-[var(--color-primary)] hover:text-white hover:-translate-y-0.5 active:scale-[0.98]",
         ghost:
-          "text-[#3D3D3D] hover:bg-[#F5F5F5] hover:text-[#1C1C1C]",
+          "text-[var(--color-primary-light)] hover:bg-[var(--color-primary-lighter)] hover:text-[var(--color-primary)]",
         link:
-          "text-[#1C1C1C] underline-offset-4 hover:underline hover:text-[#C41E3A]",
+          "text-[var(--color-primary)] underline-offset-4 hover:underline hover:text-[var(--color-brand-primary)]",
       },
       size: {
         default: "h-11 px-4 py-2",