/* style.css — 云锟智能官网样式优化版 */

/* ===== 字体 ===== */
/* fonts: system fallback */

/* ===== CSS Custom Properties (Design Tokens) ===== */
:root {
  /* Brand Colors */
  --vk-dark: #0A0E27;
  --vk-light: #F8F9FC;
  --vk-blue: #3399FF;
  --vk-pink: #FF66B2;
  --vk-purple: #9966FF;
  --vk-green: #33CC66;
  --vk-text: #1A1A2E;
  --vk-muted: #6B7280;

  /* Surface layers (depth via lightness) */
  --surface-0: #F8F9FC;
  --surface-1: #FFFFFF;
  --surface-2: #F1F3F8;
  --surface-3: #E8EBF2;

  /* Spacing scale (4px base) */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Shadows (layered, subtle) */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04), 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.06), 0 2px 4px -2px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.06), 0 4px 6px -4px rgba(0, 0, 0, 0.06);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.07), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.12);
  --shadow-glow-pink: 0 8px 30px rgba(255, 102, 178, 0.25);
  --shadow-glow-blue: 0 8px 30px rgba(51, 153, 255, 0.25);
  --shadow-glow-purple: 0 8px 30px rgba(153, 102, 255, 0.25);

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.25rem;
  --radius-3xl: 1.5rem;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --duration-fast: 150ms;
  --duration-normal: 250ms;
  --duration-slow: 400ms;

  /* Gradient brand */
  --gradient-brand: linear-gradient(135deg, var(--vk-pink), var(--vk-purple), var(--vk-blue));
  --gradient-brand-text: linear-gradient(135deg, var(--vk-pink), var(--vk-purple), var(--vk-blue));
}

/* ===== 基础 ===== */
* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  margin: 0;
  padding: 0;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  color: var(--vk-text);
  line-height: 1.6;
}

/* 语言字体切换 */
body.lang-zh { font-family: 'Noto Sans SC', 'Inter', system-ui, sans-serif; }
body.lang-en { font-family: 'Inter', 'Noto Sans SC', system-ui, sans-serif; }
body.lang-ru { font-family: 'Inter', 'Noto Sans SC', system-ui, sans-serif; }

/* Focus visible (Accessibility) */
:focus-visible {
  outline: 2px solid var(--vk-blue);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* Respect motion preferences */
@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;
  }
}

/* ===== 导航栏 ===== */
#navbar {
  transition: background-color 0.4s var(--ease-out),
              backdrop-filter 0.4s var(--ease-out),
              box-shadow 0.4s var(--ease-out);
}

#navbar.nav-scrolled {
  background-color: rgba(10, 14, 39, 0.75) !important;
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.06),
              0 4px 24px rgba(0, 0, 0, 0.25);
}

/* 导航链接 hover underline effect */
#navbar .hidden.md\:flex a {
  position: relative;
}

/* 语言切换按钮 */
.lang-btn {
  padding: var(--space-1) var(--space-2) var(--space-1) var(--space-3);
  border-radius: 9999px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: rgba(255, 255, 255, 0.6);
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-out);
  border: 1px solid transparent;
  text-transform: uppercase;
  line-height: 1.5;
}

.lang-btn:hover {
  color: rgba(255, 255, 255, 0.95);
  background: rgba(255, 255, 255, 0.08);
}

.lang-btn.active-lang {
  color: #fff;
  background: rgba(255, 102, 178, 0.15);
  border-color: rgba(255, 102, 178, 0.4);
  box-shadow: 0 0 12px rgba(255, 102, 178, 0.15);
}

/* 汉堡菜单 */
.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: rgba(255, 255, 255, 0.9);
  transition: all 0.35s var(--ease-out);
  border-radius: 2px;
  transform-origin: center;
}

.hamburger:hover span {
  background: #fff;
}

.hamburger.is-active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.hamburger.is-active span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}
.hamburger.is-active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* 移动端菜单 */
#mobile-menu {
  transition: opacity 0.3s var(--ease-out), transform 0.3s var(--ease-out);
}

#mobile-menu:not(.hidden) {
  opacity: 1;
}

#mobile-menu a {
  position: relative;
  transition: color var(--duration-fast) var(--ease-out),
              padding-left var(--duration-fast) var(--ease-out);
  padding-left: var(--space-1);
}

#mobile-menu a:hover {
  color: #fff;
  padding-left: var(--space-4);
}

/* ===== Hero ===== */
#hero {
  position: relative;
  overflow: hidden;
}

#hero-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
}

/* Hero渐变背景底层 */
.hero-bg-gradient {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(ellipse 80% 60% at 20% 80%, rgba(153, 102, 255, 0.18) 0%, transparent 70%),
    radial-gradient(ellipse 60% 50% at 80% 20%, rgba(51, 153, 255, 0.15) 0%, transparent 70%),
    radial-gradient(ellipse 40% 40% at 50% 50%, rgba(255, 102, 178, 0.10) 0%, transparent 70%),
    radial-gradient(ellipse 120% 60% at 50% 110%, rgba(51, 204, 102, 0.06) 0%, transparent 50%),
    linear-gradient(180deg, #0A0E27 0%, #0d1233 50%, #0f1540 100%);
  z-index: 0;
}

/* Hero subtitle line */
.hero-subtitle-divider {
  display: inline-block;
  width: 40px;
  height: 2px;
  background: var(--gradient-brand);
  border-radius: 1px;
  vertical-align: middle;
  margin: 0 var(--space-3);
}

/* CTA按钮 */
.cta-primary {
  background: var(--gradient-brand);
  color: #fff;
  padding: 14px 36px;
  border-radius: var(--radius-xl);
  font-weight: 600;
  font-size: 15px;
  letter-spacing: 0.01em;
  border: none;
  cursor: pointer;
  transition: transform var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-normal) var(--ease-out),
              filter var(--duration-fast);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  position: relative;
  overflow: hidden;
}

.cta-primary::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,0.15), transparent);
  opacity: 0;
  transition: opacity var(--duration-fast);
}

.cta-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow-purple), var(--shadow-xl);
}

.cta-primary:hover::after {
  opacity: 1;
}

.cta-primary:active {
  transform: translateY(0) scale(0.98);
  box-shadow: var(--shadow-md);
}

.cta-outline {
  background: transparent;
  color: rgba(255, 255, 255, 0.9);
  padding: 14px 36px;
  border-radius: var(--radius-xl);
  font-weight: 600;
  font-size: 15px;
  letter-spacing: 0.01em;
  border: 1.5px solid rgba(255, 255, 255, 0.25);
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-out);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
}

.cta-outline:hover {
  border-color: rgba(255, 255, 255, 0.6);
  background: rgba(255, 255, 255, 0.08);
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.cta-outline:active {
  transform: translateY(0) scale(0.98);
}

/* 向下滚动指示器 */
.scroll-indicator {
  animation: scrollBounce 2s ease-in-out infinite;
  opacity: 0.5;
  transition: opacity var(--duration-normal);
}

.scroll-indicator:hover {
  opacity: 0.8;
}

@keyframes scrollBounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(8px); }
}

/* ===== Section titles ===== */
.section-title {
  position: relative;
  display: inline-block;
}

.section-title-line {
  display: block;
  width: 48px;
  height: 3px;
  background: var(--gradient-brand);
  border-radius: 2px;
  margin: var(--space-4) auto 0;
}

/* ===== 产品卡片（增强动画版） ===== */

/* -- 卡片入场动画变量 -- */
.product-card {
  --tilt-max-angle: 5;
  --tilt-perspective: 800px;
  --tilt-transition: 0.4s;
  --card-hover-lift: -8px;
  --card-breathe-scale: 1.015;
  --gradient-flow-speed: 8s;
  --gradient-flow-speed-slow: 20s;

  background: var(--surface-1);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  border: 1.5px solid transparent;
  background-clip: padding-box;
  position: relative;
  overflow: hidden;
  /* 入场动画初始态 */
  opacity: 0;
  transform: translateY(40px) scale(0.95);
  transition:
    /* 入场动画（由 JS 触发 .animate-in 后生效） */
    opacity 0.7s var(--ease-out),
    transform 0.7s var(--ease-spring),
    /* 交互动画 */
    box-shadow 0.35s var(--ease-out),
    border-color 0.35s var(--ease-out);
  will-change: transform, opacity;
}

/* 入场后切换到交互态 transition */
.product-card.animate-in {
  opacity: 1;
  transform: translateY(0) scale(1);
  transition:
    opacity 0.01ms,
    transform var(--tilt-transition) var(--ease-out),
    box-shadow 0.35s var(--ease-out),
    border-color 0.35s var(--ease-out);
}

/* Stagger 延迟 */
.product-card:nth-child(1) { transition-delay: 0s, 0s, 0s, 0s; }
.product-card:nth-child(2) { transition-delay: 0.08s, 0.08s, 0s, 0s; }
.product-card:nth-child(3) { transition-delay: 0.16s, 0.16s, 0s, 0s; }
.product-card:nth-child(4) { transition-delay: 0.24s, 0.24s, 0s, 0s; }
.product-card:nth-child(5) { transition-delay: 0.32s, 0.32s, 0s, 0s; }

/* 入场后清除 stagger delay */
.product-card.animate-in:nth-child(1),
.product-card.animate-in:nth-child(2),
.product-card.animate-in:nth-child(3),
.product-card.animate-in:nth-child(4),
.product-card.animate-in:nth-child(5) {
  transition-delay: 0s;
}

/* -- 渐变边框（hover 出现） -- */
.product-card-border {
  position: absolute;
  inset: -1.5px;
  border-radius: inherit;
  background: linear-gradient(135deg, var(--card-color-from), var(--card-color-to));
  opacity: 0;
  z-index: -1;
  transition: opacity 0.35s var(--ease-out);
}

.product-card:hover .product-card-border {
  opacity: 1;
}

/* -- Spotlight / 光追效果 -- */
.product-card-spotlight {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-radius: inherit;
  background: radial-gradient(600px circle at var(--mouse-x, 50%) var(--mouse-y, 50%),
    rgba(153, 102, 255, 0.04), transparent 40%);
  opacity: 0;
  transition: opacity 0.35s;
  pointer-events: none;
  z-index: 1;
}

.product-card:hover .product-card-spotlight {
  opacity: 1;
}

/* -- 顶部渐变装饰区域 -- */
.product-card-header {
  position: relative;
  height: 4px;
  width: 100%;
  margin-bottom: var(--space-6);
  border-radius: 4px;
  background: linear-gradient(90deg, #ffffff, #ffffff);
  background-size: 200% 100%;
  opacity: 0.3;
  transition: all 0.35s var(--ease-out);
  /* 持续微弱流动 */
  animation: gradientFlowSlow var(--gradient-flow-speed-slow) linear infinite;
  transform-origin: left center;
}

/* hover 时变为品牌色渐变 + 加深 */
.product-card:hover .product-card-header {
  animation: gradientFlow var(--gradient-flow-speed) linear infinite;
  opacity: 1;
  height: 8px;
  background: linear-gradient(90deg, #ffffff, var(--card-color-to), var(--card-color-from), #ffffff);
  background-size: 200% 100%;
}

@keyframes gradientFlow {
  0%   { background-position: 0% 50%; }
  100% { background-position: 200% 50%; }
}

@keyframes gradientFlowSlow {
  0%   { background-position: 0% 50%; }
  100% { background-position: 200% 50%; }
}

/* -- Hover 状态 -- */
.product-card:hover {
  box-shadow: var(--shadow-xl),
              0 8px 32px rgba(0, 0, 0, 0.08);
  border-color: transparent;
}

/* 3D tilt 由 JS 内联 style 控制，不写在 :hover 中避免冲突 */

/* -- 标题 hover 颜色变化 -- */
.product-card-title {
  transition: color 0.35s var(--ease-out);
}

.product-card:hover .product-card-title {
  color: #1A1A2E;
  font-weight: 700;
}

/* -- 描述文字 hover 展开 -- */
.product-card-desc {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  transition: -webkit-line-clamp 0.3s;
}

.product-card:hover .product-card-desc {
  -webkit-line-clamp: unset;
}

/* -- 底部装饰线（hover 从左到右展开） -- */
.product-card-footer-line {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--card-color-from), var(--card-color-to));
  border-radius: 0 0 var(--radius-2xl) var(--radius-2xl);
  transition: width 0.5s var(--ease-out);
  z-index: 2;
}

.product-card:hover .product-card-footer-line {
  width: 100%;
}

/* -- 图标 -- */
.product-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: var(--space-5);
  transition: transform var(--duration-normal) var(--ease-spring);
}

.product-card:hover .product-icon {
  transform: scale(1.1) translateY(-2px);
}

/* -- 减弱动画偏好 -- */
@media (prefers-reduced-motion: reduce) {
  .product-card {
    opacity: 1;
    transform: none;
    transition: box-shadow 0.15s var(--ease-out),
                border-color 0.15s var(--ease-out);
  }

  .product-card-header {
    animation: none;
  }

  .product-card-footer-line {
    transition: none;
  }

  .product-card-title {
    transition: none;
  }
}

/* ===== 优势板块 ===== */
.advantage-item {
  display: flex;
  gap: var(--space-6);
  align-items: flex-start;
}

.advantage-num {
  font-size: 52px;
  font-weight: 800;
  line-height: 1;
  background: var(--gradient-brand-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  flex-shrink: 0;
  width: 80px;
  opacity: 0.7;
  transition: opacity var(--duration-normal) var(--ease-out);
}

.advantage-item:hover .advantage-num {
  opacity: 1;
}

.advantage-visual {
  width: 100%;
  height: 200px;
  border-radius: var(--radius-xl);
  overflow: hidden;
  position: relative;
  border: 1px solid var(--surface-3);
  transition: box-shadow var(--duration-normal) var(--ease-out);
}

.advantage-visual:hover {
  box-shadow: var(--shadow-lg);
}

/* ===== 数据卡片 ===== */
.result-card {
  text-align: center;
  padding: var(--space-10) var(--space-6);
  border-radius: var(--radius-2xl);
  background: var(--surface-1);
  border: 1px solid var(--surface-3);
  transition: transform var(--duration-normal) var(--ease-out),
              box-shadow var(--duration-normal) var(--ease-out),
              border-color var(--duration-normal) var(--ease-out);
  position: relative;
  overflow: hidden;
}

.result-card::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-brand);
  opacity: 0;
  transition: opacity var(--duration-normal) var(--ease-out);
}

.result-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(153, 102, 255, 0.12);
}

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

.result-number {
  font-size: 56px;
  font-weight: 800;
  background: var(--gradient-brand-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

/* ===== 联系表单 ===== */
.form-input {
  width: 100%;
  padding: 14px 18px;
  border: 1.5px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-lg);
  font-size: 15px;
  transition: border-color var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-fast) var(--ease-out),
              background var(--duration-fast);
  background: rgba(255, 255, 255, 0.04);
  outline: none;
  font-family: inherit;
  color: #fff;
}

.form-input::placeholder {
  color: rgba(255, 255, 255, 0.35);
}

.form-input:hover {
  border-color: rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.06);
}

.form-input:focus {
  border-color: var(--vk-blue);
  box-shadow: 0 0 0 3px rgba(51, 153, 255, 0.15);
  background: rgba(255, 255, 255, 0.08);
}

.form-submit {
  width: 100%;
  padding: 15px;
  background: var(--gradient-brand);
  color: #fff;
  border: none;
  border-radius: var(--radius-lg);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: transform var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-normal) var(--ease-out),
              filter var(--duration-fast);
  position: relative;
  overflow: hidden;
}

.form-submit:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow-purple), var(--shadow-xl);
}

.form-submit:active {
  transform: translateY(0) scale(0.98);
  box-shadow: var(--shadow-md);
}

/* ===== 合作对象卡片 ===== */
.partner-card {
  padding: var(--space-6);
  border-radius: var(--radius-xl);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  transition: all var(--duration-normal) var(--ease-out);
}

.partner-card:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 102, 178, 0.25);
  transform: translateX(4px);
}

/* ===== 滚动动画 (enhanced) ===== */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}

.animate-on-scroll.animate-in {
  opacity: 1;
  transform: translateY(0);
}

/* 延迟类 */
.delay-1 { transition-delay: 0.08s; }
.delay-2 { transition-delay: 0.16s; }
.delay-3 { transition-delay: 0.24s; }
.delay-4 { transition-delay: 0.32s; }
.delay-5 { transition-delay: 0.40s; }

/* ===== Footer ===== */
.footer-link {
  color: rgba(255, 255, 255, 0.5);
  text-decoration: none;
  transition: color var(--duration-fast) var(--ease-out),
              padding-left var(--duration-fast) var(--ease-out);
  font-size: 14px;
  padding-left: 0;
}

.footer-link:hover {
  color: #fff;
  padding-left: var(--space-1);
}

/* ===== 几何装饰 SVG ===== */
.geo-pattern {
  position: absolute;
  opacity: 0.06;
  pointer-events: none;
}

/* ===== About 板块视觉 ===== */
.about-visual {
  width: 100%;
  border-radius: var(--radius-2xl);
  overflow: hidden;
  box-shadow: var(--shadow-2xl);
  transition: transform var(--duration-slow) var(--ease-out);
}

.about-visual:hover {
  transform: scale(1.01);
}

.about-svg {
  display: block;
  width: 100%;
  height: auto;
}

.about-iot-img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--radius-2xl);
}

/* ===== Hero 背景图片 ===== */
.hero-bg-image {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: url('../images/hero-v2.jpg');
  background-size: cover;
  background-position: center;
  opacity: 0.3;
  z-index: 0;
}

/* ===== 产品卡片图片 ===== */
.product-card-image-wrap {
  width: 100%;
  height: 200px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: var(--space-5);
  background: var(--surface-2);
}

.product-card-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform var(--duration-slow) var(--ease-out);
}

.product-card:hover .product-card-image {
  transform: scale(1.05);
}

/* ===== 联系我们背景图片 ===== */
.contact-bg-image {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: url('../images/contact-bg.jpg');
  background-size: cover;
  background-position: center;
  opacity: 0.15;
  z-index: 0;
  pointer-events: none;
}

/* ===== 移动端图片自适应 ===== */
@media (max-width: 768px) {
  .product-card-image-wrap {
    height: 160px;
  }

  .about-visual {
    max-height: 320px;
  }
}

/* ===== Products 板块背景装饰 ===== */
.products-bg-decor {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 0;
}

.products-bg-svg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* ===== Results 板块背景装饰 ===== */
.results-bg-decor {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 0;
}

.results-bg-svg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* ===== Contact 板块增强光斑 ===== */
.contact-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
}

.contact-blob-1 {
  top: -10%;
  left: 15%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(153, 102, 255, 0.08) 0%, transparent 70%);
}

.contact-blob-2 {
  bottom: -15%;
  right: 10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(51, 153, 255, 0.07) 0%, transparent 70%);
}

.contact-blob-3 {
  top: 40%;
  left: 50%;
  transform: translateX(-50%);
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(255, 102, 178, 0.04) 0%, transparent 70%);
}

/* ===== 页面加载动画 ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-content h1 {
  animation: fadeInUp 0.8s var(--ease-out) 0.2s both;
}

.hero-content p {
  animation: fadeInUp 0.8s var(--ease-out) 0.4s both;
}

.hero-content .cta-primary {
  animation: fadeInUp 0.8s var(--ease-out) 0.6s both;
}

.hero-content .cta-outline {
  animation: fadeInUp 0.8s var(--ease-out) 0.7s both;
}

/* ===== Selection color ===== */
::selection {
  background: rgba(153, 102, 255, 0.25);
  color: var(--vk-text);
}

/* ===== Scrollbar (Webkit) ===== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--surface-0);
}

::-webkit-scrollbar-thumb {
  background: var(--surface-3);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #c5c9d4;
}

/* ===== Loading 动画 ===== */
#loading-screen {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: var(--vk-dark);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  transition: opacity 0.4s ease, visibility 0.4s ease;
}

#loading-screen.loaded {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

#loading-screen .loading-logo {
  width: 80px;
  height: 80px;
  animation: loadingShrink 1.2s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}

@keyframes loadingShrink {
  0% { transform: scale(1); opacity: 1; }
  60% { transform: scale(1.05); opacity: 1; }
  100% { transform: scale(0.3); opacity: 0; }
}

#loading-screen .loading-ring {
  position: absolute;
  width: 100px;
  height: 100px;
  border: 2px solid transparent;
  border-top-color: var(--vk-blue);
  border-right-color: var(--vk-purple);
  border-radius: 50%;
  animation: loadingSpin 0.8s linear infinite;
}

@keyframes loadingSpin {
  to { transform: rotate(360deg); }
}

/* ===== 粒子背景 (全页 fixed canvas) ===== */
#particles-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* ===== Scroll Reveal 动画 ===== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger delays for reveal children */
.reveal[data-reveal-delay="1"] { transition-delay: 0.1s; }
.reveal[data-reveal-delay="2"] { transition-delay: 0.2s; }
.reveal[data-reveal-delay="3"] { transition-delay: 0.3s; }
.reveal[data-reveal-delay="4"] { transition-delay: 0.4s; }
.reveal[data-reveal-delay="5"] { transition-delay: 0.5s; }
.reveal[data-reveal-delay="6"] { transition-delay: 0.6s; }
.reveal[data-reveal-delay="7"] { transition-delay: 0.7s; }

/* ===== 导航栏增强 ===== */
#navbar.nav-scrolled {
  background-color: rgba(10, 14, 39, 0.85) !important;
  backdrop-filter: blur(12px) saturate(180%);
  -webkit-backdrop-filter: blur(12px) saturate(180%);
  border-bottom: 1px solid transparent;
  border-image: linear-gradient(90deg, var(--vk-blue), var(--vk-purple)) 1;
  box-shadow: none;
}

/* 导航链接下划线动画 */
.nav-link {
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--gradient-brand);
  border-radius: 1px;
  transition: width 0.3s cubic-bezier(0.16, 1, 0.3, 1), left 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.nav-link:hover::after {
  width: 60%;
  left: 20%;
}

/* ===== AI 对话演示模块 ===== */
#ai-demo {
  position: relative;
  z-index: 1;
}

.ai-chat-container {
  max-width: 640px;
  margin: 0 auto;
  background: rgba(10, 14, 39, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: var(--radius-2xl);
  border: 1px solid rgba(255, 255, 255, 0.1);
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3),
              0 0 40px rgba(51, 153, 255, 0.05);
}

.ai-chat-header {
  padding: 16px 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  align-items: center;
  gap: 12px;
}

.ai-chat-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--gradient-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.ai-chat-header-text h4 {
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  margin: 0;
}

.ai-chat-header-text p {
  color: rgba(255, 255, 255, 0.4);
  font-size: 12px;
  margin: 2px 0 0 0;
}

.ai-chat-status {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--vk-green);
  margin-left: auto;
  flex-shrink: 0;
  animation: chatPulse 2s ease-in-out infinite;
}

@keyframes chatPulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(51, 204, 102, 0.4); }
  50% { opacity: 0.7; box-shadow: 0 0 0 4px rgba(51, 204, 102, 0); }
}

.ai-chat-messages {
  padding: 20px;
  height: 320px;
  overflow-y: auto;
  scroll-behavior: smooth;
}

.ai-chat-messages::-webkit-scrollbar {
  width: 4px;
}

.ai-chat-messages::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 2px;
}

.ai-msg {
  margin-bottom: 16px;
  display: flex;
  gap: 10px;
  opacity: 0;
  transform: translateY(10px);
  animation: msgFadeIn 0.4s ease forwards;
}

@keyframes msgFadeIn {
  to { opacity: 1; transform: translateY(0); }
}

.ai-msg-bot {
  flex-direction: row;
}

.ai-msg-user {
  flex-direction: row-reverse;
}

.ai-msg-bubble {
  max-width: 80%;
  padding: 10px 14px;
  border-radius: 16px;
  font-size: 14px;
  line-height: 1.6;
  word-break: break-word;
}

.ai-msg-bot .ai-msg-bubble {
  background: rgba(255, 255, 255, 0.08);
  color: rgba(255, 255, 255, 0.9);
  border-bottom-left-radius: 4px;
}

.ai-msg-user .ai-msg-bubble {
  background: linear-gradient(135deg, var(--vk-blue), var(--vk-purple));
  color: #fff;
  border-bottom-right-radius: 4px;
}

.ai-msg-avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  flex-shrink: 0;
  background: rgba(255, 255, 255, 0.1);
}

.ai-msg-user .ai-msg-avatar {
  background: var(--gradient-brand);
}

/* Typing indicator */
.ai-typing {
  display: flex;
  gap: 4px;
  padding: 12px 16px;
  align-items: center;
}

.ai-typing span {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  animation: typingBounce 1.4s ease-in-out infinite;
}

.ai-typing span:nth-child(2) { animation-delay: 0.2s; }
.ai-typing span:nth-child(3) { animation-delay: 0.4s; }

@keyframes typingBounce {
  0%, 60%, 100% { transform: translateY(0); opacity: 0.4; }
  30% { transform: translateY(-6px); opacity: 1; }
}

.ai-chat-quick-actions {
  padding: 16px 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.ai-quick-btn {
  padding: 8px 14px;
  border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  background: rgba(255, 255, 255, 0.05);
  color: rgba(255, 255, 255, 0.7);
  font-size: 13px;
  cursor: pointer;
  transition: all 0.25s ease;
  white-space: nowrap;
}

.ai-quick-btn:hover {
  border-color: var(--vk-blue);
  background: rgba(51, 153, 255, 0.1);
  color: #fff;
  transform: translateY(-1px);
}

.ai-quick-btn:active {
  transform: translateY(0) scale(0.97);
}

.ai-quick-btn.disabled {
  opacity: 0.4;
  pointer-events: none;
}

/* ===== 响应式补充 ===== */
@media (max-width: 768px) {
  .advantage-item {
    flex-direction: column;
    gap: var(--space-2);
  }

  .advantage-num {
    font-size: 40px;
    width: auto;
  }

  .result-number {
    font-size: 44px;
  }

  .cta-primary, .cta-outline {
    padding: 13px 28px;
    font-size: 14px;
    width: 100%;
  }

  .product-card {
    padding: var(--space-6);
  }

  /* About visual responsive */

  /* About visual responsive */
  .about-visual {
    max-height: 320px;
  }

  /* Products/Results background - simplify on mobile */
  .products-bg-decor,
  .results-bg-decor {
    opacity: 0.5;
  }

  /* Contact blobs - smaller on mobile */
  .contact-blob-1 { width: 250px; height: 250px; }
  .contact-blob-2 { width: 300px; height: 300px; }
  .contact-blob-3 { width: 200px; height: 200px; }
}

@media (max-width: 1024px) and (min-width: 769px) {
  .advantage-num {
    font-size: 44px;
    width: 64px;
  }
}

/* ===== Fluid Typography ===== */
.hero-content h1 {
  font-size: clamp(2rem, 5vw, 4.5rem);
  letter-spacing: -0.03em;
}

.hero-content p {
  font-size: clamp(1rem, 2vw, 1.375rem);
}

#about h2, #products h2, #advantages h2, #results h2, #contact h2 {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  letter-spacing: -0.02em;
}

/* ===== Smooth section separators ===== */
section {
  position: relative;
  z-index: 1;
}

/* ==========================================================
   EFFECT 1: 滚动视差 (Parallax)
   ========================================================== */

/* 视差层定义 — Hero 内部三层不同速率 */
.parallax-layer {
  will-change: transform;
  transition: none;
}

#hero-canvas {
  /* 粒子背景层：最慢（远离观察者） */
  --parallax-speed: 0.15;
}

.hero-content {
  /* Slogan+副标题层：中速 */
  --parallax-speed: 0.35;
}

.scroll-indicator {
  /* 最快（靠近观察者） */
  --parallax-speed: 0.55;
}

/* 移动端视差幅度减半 */
@media (max-width: 768px) {
  #hero-canvas { --parallax-speed: 0.08; }
  .hero-content { --parallax-speed: 0.18; }
  .scroll-indicator { --parallax-speed: 0.28; }
}

/* ==========================================================
   EFFECT 2: 鼠标跟随光效 (Mouse Follow Glow)
   ========================================================== */

/* 全局跟随光晕 */
#mouse-glow {
  position: fixed;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  background: radial-gradient(
    circle,
    rgba(51, 153, 255, 0.15) 0%,
    rgba(51, 153, 255, 0.05) 40%,
    transparent 70%
  );
  pointer-events: none;
  z-index: 9998;
  transform: translate(-50%, -50%);
  transition: left 0.1s ease-out, top 0.1s ease-out;
  opacity: 0;
  will-change: left, top, opacity;
}

#mouse-glow.active {
  opacity: 1;
}

/* 卡片光泽效果 — 在 .product-card hover 时叠加信用卡反光 */
.product-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-radius: inherit;
  background: radial-gradient(
    300px circle at var(--glow-x, 50%) var(--glow-y, 50%),
    rgba(255, 255, 255, 0.12) 0%,
    rgba(255, 255, 255, 0.03) 30%,
    transparent 60%
  );
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
  z-index: 3;
}

.product-card:hover::after {
  opacity: 1;
}

/* 移动端不显示鼠标光效 */
@media (hover: none) {
  #mouse-glow { display: none; }
  .product-card::after { display: none; }
}

/* ==========================================================
   EFFECT 3: 滚动进度条 + 章节过渡
   ========================================================== */

/* 顶部进度条 */
#scroll-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--vk-blue), var(--vk-purple));
  z-index: 100;
  transition: opacity 0.3s ease;
  will-change: width;
  border-radius: 0 2px 2px 0;
}

/* 进度条在导航栏区域内变为半透明 */
#navbar.nav-scrolled ~ #scroll-progress-bar,
#scroll-progress-bar.nav-transparent {
  opacity: 0.4;
}

/* 章节过渡动画 */
[data-section] {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-section].section-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Hero section 不需要章节过渡（它有自己的入场动画） */
#hero[data-section],
[data-section]#hero {
  opacity: 1;
  transform: none;
}

/* ===== 全局鼠标跟随光标 ===== */
#cursor-glow-dot {
  position: fixed;
  width: 8px;
  height: 8px;
  background: radial-gradient(circle, rgba(153, 102, 255, 0.9), rgba(255, 102, 178, 0.6));
  border-radius: 50%;
  pointer-events: none;
  z-index: 10000;
  transform: translate(-50%, -50%);
  transition: width 0.2s, height 0.2s, background 0.2s;
  mix-blend-mode: screen;
  filter: blur(0.5px);
}

#cursor-glow-dot.cursor-hover {
  width: 16px;
  height: 16px;
  background: radial-gradient(circle, rgba(255, 102, 178, 0.95), rgba(153, 102, 255, 0.7));
  filter: blur(1px);
}

#cursor-glow-trail {
  position: fixed;
  width: 40px;
  height: 40px;
  background: radial-gradient(circle, rgba(153, 102, 255, 0.15), transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  z-index: 9999;
  transform: translate(-50%, -50%);
  transition: width 0.3s, height 0.3s;
  mix-blend-mode: screen;
}

#cursor-glow-trail.cursor-hover {
  width: 60px;
  height: 60px;
  background: radial-gradient(circle, rgba(255, 102, 178, 0.2), transparent 70%);
}

.cursor-particle {
  position: fixed;
  width: 4px;
  height: 4px;
  background: rgba(153, 102, 255, 0.7);
  border-radius: 50%;
  pointer-events: none;
  z-index: 9998;
  transform: translate(-50%, -50%);
  mix-blend-mode: screen;
}


/* Loading screen fallback */
#loading-screen {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  z-index: 99999;
  background: #0A0E27;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.5s;
}
#loading-screen.fade-out {
  opacity: 0 !important;
  pointer-events: none;
}