/* ========================================
   视频大脑官网 - 设计系统
   ======================================== */

/* 字体引入 */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800;900&display=swap');

/* 基础重置 */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  background-color: #ffffff;
  color: #1f2937;
  line-height: 1.6;
}

/* ========================================
   品牌色扩展
   ======================================== */

:root {
  --brand-50:  #F5F3FF;
  --brand-100: #EDE9FE;
  --brand-200: #DDD6FE;
  --brand-300: #C4B5FD;
  --brand-400: #A78BFA;
  --brand-500: #8B5CF6;
  --brand-600: #7C3AED;
  --brand-700: #6D28D9;
  --brand-800: #5B21B6;
  --brand-900: #4C1D95;
}

/* ========================================
   工具类 / Utilities
   ======================================== */

/* 文字渐变 */
.text-gradient {
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-image: linear-gradient(90deg, #6B46C1, #3B82F6);
}

/* 背景渐变 */
.bg-gradient-primary {
  background-image: linear-gradient(90deg, #8B5CF6, #D946EF);
}

.bg-gradient-hero {
  background-image: radial-gradient(circle at 50% 0%, rgba(139, 92, 246, 0.08) 0%, transparent 70%);
}

/* Hero 图形居中 */
.hero-graphic-center {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

/* 轨道动画 */
.orbit-circle {
  position: absolute;
  border: 1px dashed #E5E7EB;
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.orbit-item {
  position: absolute;
  transform-origin: center;
}

/* ========================================
   全局质感升级
   ======================================== */

/* 微妙噪点纹理 */
.noise-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
  opacity: 0.03;
  pointer-events: none;
  z-index: 1;
}

/* 多层阴影 - 卡片悬浮 */
.shadow-card {
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.04),
    0 4px 8px rgba(0, 0, 0, 0.03),
    0 12px 24px rgba(0, 0, 0, 0.02);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.shadow-card:hover {
  box-shadow:
    0 2px 4px rgba(0, 0, 0, 0.04),
    0 8px 16px rgba(0, 0, 0, 0.04),
    0 24px 48px rgba(0, 0, 0, 0.06);
  transform: translateY(-2px);
}

/* 卡片3D hover */
.card-3d {
  transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  transform-style: preserve-3d;
  perspective: 1000px;
}

.card-3d:hover {
  transform: translateY(-4px) rotateX(2deg);
  box-shadow:
    0 20px 40px -12px rgba(124, 58, 237, 0.15),
    0 8px 16px -4px rgba(0, 0, 0, 0.04);
}

/* 数字计数动画 */
@keyframes countUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.count-animate {
  animation: countUp 0.8s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

/* 连接线脉冲动画 */
@keyframes pulse-line {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}

.pulse-arrow {
  animation: pulse-line 2s ease-in-out infinite;
}

/* Tab滑动指示器 */
.tab-indicator {
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 大数字展示 */
.stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.02em;
}

/* 玻璃拟态 */
.glassmorphism {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid rgba(255, 255, 255, 0.5);
}

/* 平滑过渡 */
a, button {
  transition: all 0.2s ease-in-out;
}

/* ========================================
   功能列表选中状态
   ======================================== */

#feature-list .feature-item {
  border-left: 3px solid transparent;
}

#feature-list .feature-item:hover {
  background-color: #F9FAFB;
}

#feature-list .feature-item.active {
  background-color: #F5F3FF;
  border-left-color: #8B5CF6;
}

#feature-list .feature-item.active .feature-title {
  color: #7C3AED;
}

/* ========================================
   痛点卡片 - 左侧色条标识
   ======================================== */

.pain-card {
  position: relative;
  overflow: hidden;
}

.pain-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 100%;
  background: linear-gradient(to bottom, var(--card-accent, #8B5CF6), transparent);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.pain-card:hover::before {
  opacity: 1;
}

/* ========================================
   工作流程步骤 - 连接线效果
   ======================================== */

.workflow-step {
  position: relative;
}

/* ========================================
   表单区域玻璃效果
   ======================================== */

.glass-form-bg {
  background: linear-gradient(135deg, rgba(124, 58, 237, 0.95) 0%, rgba(139, 92, 246, 0.9) 50%, rgba(217, 70, 239, 0.85) 100%);
  position: relative;
  overflow: hidden;
}

.glass-form-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  opacity: 0.04;
  mix-blend-mode: overlay;
}

/* ========================================
   滚动条隐藏
   ======================================== */

.hide-scrollbar::-webkit-scrollbar {
  display: none;
}

/* ========================================
   响应式字体层级
   ======================================== */

@media (min-width: 768px) {
  .section-title {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.15;
  }
}

@media (max-width: 767px) {
  .section-title {
    font-size: 1.75rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    line-height: 1.2;
  }
}

/* ========================================
   工作流程 - 编号Badge颜色
   ======================================== */

.step-num {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 800;
  color: white;
  flex-shrink: 0;
}

.step-num-01 { background: linear-gradient(135deg, #3B82F6, #60A5FA); }
.step-num-02 { background: linear-gradient(135deg, #8B5CF6, #A78BFA); }
.step-num-03 { background: linear-gradient(135deg, #6366F1, #818CF8); }
.step-num-04 { background: linear-gradient(135deg, #EC4899, #F472B6); }
.step-num-05 { background: linear-gradient(135deg, #F97316, #FB923C); }
.step-num-06 { background: linear-gradient(135deg, #EF4444, #F87171); }
.step-num-07 { background: linear-gradient(135deg, #10B981, #34D399); }
.step-num-08 { background: linear-gradient(135deg, #06B6D4, #22D3EE); }

.step-bar-01 { background: linear-gradient(90deg, #3B82F6, #60A5FA); }
.step-bar-02 { background: linear-gradient(90deg, #8B5CF6, #A78BFA); }
.step-bar-03 { background: linear-gradient(90deg, #6366F1, #818CF8); }
.step-bar-04 { background: linear-gradient(90deg, #EC4899, #F472B6); }
.step-bar-05 { background: linear-gradient(90deg, #F97316, #FB923C); }
.step-bar-06 { background: linear-gradient(90deg, #EF4444, #F87171); }
.step-bar-07 { background: linear-gradient(90deg, #10B981, #34D399); }
.step-bar-08 { background: linear-gradient(90deg, #06B6D4, #22D3EE); }

/* 工作流程卡片 */
.workflow-card {
  background: white;
  border-radius: 16px;
  border: 1px solid #F3F4F6;
  padding: 24px 20px;
  position: relative;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  overflow: visible;
}

.workflow-card:hover {
  border-color: #DDD6FE;
  box-shadow: 0 8px 24px -4px rgba(124, 58, 237, 0.1);
  transform: translateY(-2px);
}

/* 桌面端U型连接 - SVG */
.u-connector {
  position: relative;
  height: 60px;
  margin: 8px 0;
}

.u-connector svg {
  width: 100%;
  height: 100%;
  overflow: visible;
}

/* 移动端时间线 */
.workflow-timeline {
  position: relative;
  padding-left: 44px;
}

.workflow-timeline::before {
  content: '';
  position: absolute;
  left: 14px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(to bottom, #C4B5FD, #A78BFA, #F472B6);
}

.workflow-timeline .timeline-step {
  position: relative;
  padding-bottom: 20px;
}

.workflow-timeline .timeline-step:last-child {
  padding-bottom: 0;
}

.workflow-timeline .timeline-badge {
  position: absolute;
  left: -38px;
  top: 0;
  z-index: 2;
}

/* ========================================
   移动端体验优化 - 新增工具类
   ======================================== */

/* 横向滚动提示：必须通过 --scroll-hint-bg 变量匹配容器背景色 */
.scroll-hint {
  position: relative;
}
.scroll-hint::after {
  content: '';
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 40px;
  background: linear-gradient(to right, transparent, var(--scroll-hint-bg, #ffffff));
  pointer-events: none;
  transition: opacity 0.3s ease;
}
.scroll-hint.scrolled-end::after {
  opacity: 0;
}

/* 底部固定 CTA 条 */
.mobile-sticky-cta {
  transform: translateY(100%);
  transition: transform 0.3s ease;
}
.mobile-sticky-cta.visible {
  transform: translateY(0);
}

/* 客户评价轮播吸附 */
.testimonial-track {
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}
.testimonial-card {
  scroll-snap-align: start;
}

/* 移动端菜单滑入动画 */
.mobile-menu-slide {
  transform: translateY(-10px);
  opacity: 0;
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.mobile-menu-slide.open {
  transform: translateY(0);
  opacity: 1;
}

/* ========================================
   毛玻璃效果
   ======================================== */

.glass {
  background: rgba(255, 255, 255, 0.55);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border: 1px solid rgba(255, 255, 255, 0.5);
}

.glass-strong {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid rgba(255, 255, 255, 0.6);
}

.glass-card {
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.5) 0%, rgba(255, 255, 255, 0.1) 100%);
  backdrop-filter: blur(12px) saturate(160%);
  -webkit-backdrop-filter: blur(12px) saturate(160%);
  border: 1px solid rgba(255, 255, 255, 0.45);
}

.glass-tint {
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.35) 0%, rgba(255, 255, 255, 0.05) 100%);
  backdrop-filter: blur(10px) saturate(140%);
  -webkit-backdrop-filter: blur(10px) saturate(140%);
  border: 1px solid rgba(255, 255, 255, 0.35);
}

/* ========================================
   滚动进入动画
   ======================================== */

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-stagger > * {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal-stagger.is-visible > *:nth-child(1) { transition-delay: 0ms; }
.reveal-stagger.is-visible > *:nth-child(2) { transition-delay: 80ms; }
.reveal-stagger.is-visible > *:nth-child(3) { transition-delay: 160ms; }
.reveal-stagger.is-visible > *:nth-child(4) { transition-delay: 240ms; }
.reveal-stagger.is-visible > *:nth-child(5) { transition-delay: 320ms; }
.reveal-stagger.is-visible > *:nth-child(6) { transition-delay: 400ms; }
.reveal-stagger.is-visible > *:nth-child(7) { transition-delay: 480ms; }
.reveal-stagger.is-visible > *:nth-child(8) { transition-delay: 560ms; }

.reveal-stagger.is-visible > * {
  opacity: 1;
  transform: translateY(0);
}

/* ========================================
   Hero 背景呼吸动画
   ======================================== */

@keyframes hero-breathe {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.hero-glow {
  animation: hero-breathe 8s ease-in-out infinite;
}

/* ========================================
   数字计数动画
   ======================================== */

.count-up {
  font-variant-numeric: tabular-nums;
}

.count-up[data-text="true"] {
  opacity: 0;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .mobile-menu-slide {
    transform: none;
    opacity: 1;
  }
  .reveal,
  .reveal-stagger > *,
  .count-up[data-text="true"] {
    opacity: 1 !important;
    transform: none !important;
  }
  .hero-glow {
    animation: none !important;
  }
}