/* ==========================================================================
   闪电机场 (ShanDianJiChang) - 速度隧道 + 超频闪电 + 动感科技 样式表
   零重型框架 | 纯原生 CSS | 毫秒级秒开 | 极致 3D 隧道动效
   ========================================================================== */

:root {
  /* 【配色规范】 */
  --bg-main: #000000;              /* 主背景：纯黑 */
  --primary-red: #EF4444;          /* 主色：超频红 */
  --lightning-yellow: #FCD34D;     /* 次色：闪电黄 */
  --text-main: #FFFFFF;            /* 文字：纯白 */
  --text-muted: rgba(255, 255, 255, 0.7); /* 次级文本 */
  --text-dim: rgba(255, 255, 255, 0.45);
  
  --bg-card: rgba(12, 10, 16, 0.85);
  --bg-card-hover: rgba(22, 14, 28, 0.95);
  --border-color: rgba(239, 68, 68, 0.22);
  --border-yellow: rgba(252, 211, 77, 0.35);

  --font-heading: 'Russo One', Impact, 'Arial Black', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, 'PingFang SC', 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  --radius-btn: 8px;
}

/* 锚点防固定页眉遮挡 (页眉高度 72px) */
section[id], article[id], div[id], h1[id], h2[id], h3[id] {
  scroll-margin-top: 84px;
}

/* 键盘无障碍跳过主要内容链接 (Skip link) */
.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  background: var(--lightning-yellow);
  color: #000000;
  padding: 12px 20px;
  font-weight: 700;
  border-radius: var(--radius-btn);
  z-index: 99999;
  text-decoration: none;
  box-shadow: 0 4px 14px rgba(252, 211, 77, 0.5);
  transition: top 0.2s ease;
}
.skip-link:focus {
  top: 16px;
  outline: 3px solid var(--primary-red);
}

/* 键盘焦点指示器 */
:focus-visible {
  outline: 2px solid var(--lightning-yellow);
  outline-offset: 3px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-main);
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  -webkit-font-smoothing: antialiased;
}

/* ==========================================================================
   【背景动效】：20条速度光线 + 底部50%透视网格 + 细密扫描线纹理
   ========================================================================== */

/* 1. 细密扫描线纹理 */
.scanlines-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: repeating-linear-gradient(
    0deg,
    rgba(0, 0, 0, 0.35) 0px,
    rgba(0, 0, 0, 0.35) 1px,
    transparent 1px,
    transparent 3px
  );
  pointer-events: none;
  z-index: 99;
}

/* 2. 底部 50% 区域透视网格（红/黄混合，3秒一周期快速向观察者滚动） */
.perspective-grid-floor {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 50%;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
  perspective: 320px;
  mask-image: linear-gradient(to top, rgba(0, 0, 0, 1) 0%, rgba(0, 0, 0, 0.6) 65%, transparent 100%);
  -webkit-mask-image: linear-gradient(to top, rgba(0, 0, 0, 1) 0%, rgba(0, 0, 0, 0.6) 65%, transparent 100%);
}

.perspective-grid-inner {
  position: absolute;
  top: -60%;
  left: -50%;
  width: 200%;
  height: 200%;
  transform: rotateX(76deg);
  transform-origin: center bottom;
  background-image: 
    linear-gradient(to right, rgba(239, 68, 68, 0.45) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(252, 211, 77, 0.4) 1px, transparent 1px);
  background-size: 50px 50px;
  animation: gridRollForward 3s linear infinite;
}

@keyframes gridRollForward {
  0% {
    background-position: 0 0;
  }
  100% {
    background-position: 0 50px;
  }
}

/* 3. 20 条红/黄速度光线从顶部斜向下穿过屏幕（1-2秒周期，角度各异 ±30°，带辉光阴影） */
.speed-lines-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
  overflow: hidden;
}

.speed-line {
  position: absolute;
  top: -160px;
  width: 2px;
  height: 140px;
  opacity: 0;
  will-change: transform, opacity;
  animation: speedLineShoot linear infinite;
}

/* 红光线与黄光线辉光 */
.line-red {
  background: linear-gradient(180deg, transparent 0%, #EF4444 80%, #fff 100%);
  box-shadow: 0 0 14px #EF4444, 0 0 28px rgba(239, 68, 68, 0.6);
}

.line-yellow {
  background: linear-gradient(180deg, transparent 0%, #FCD34D 80%, #fff 100%);
  box-shadow: 0 0 14px #FCD34D, 0 0 28px rgba(252, 211, 77, 0.6);
}

@keyframes speedLineShoot {
  0% {
    transform: translateY(0) rotate(var(--angle, 15deg));
    opacity: 0;
  }
  15% {
    opacity: 0.95;
  }
  85% {
    opacity: 0.95;
  }
  100% {
    transform: translateY(125vh) rotate(var(--angle, 15deg));
    opacity: 0;
  }
}

/* 20条光线的离散分布（1-2秒周期，±30°角度） */
.speed-line:nth-child(1)  { left: 3%;  --angle: -18deg; animation-duration: 1.2s; animation-delay: 0.1s; }
.speed-line:nth-child(2)  { left: 8%;  --angle: 12deg;  animation-duration: 1.8s; animation-delay: 0.7s; }
.speed-line:nth-child(3)  { left: 14%; --angle: -26deg; animation-duration: 1.1s; animation-delay: 0.3s; }
.speed-line:nth-child(4)  { left: 19%; --angle: 24deg;  animation-duration: 1.5s; animation-delay: 1.1s; }
.speed-line:nth-child(5)  { left: 25%; --angle: -8deg;  animation-duration: 1.3s; animation-delay: 0.5s; }
.speed-line:nth-child(6)  { left: 31%; --angle: 16deg;  animation-duration: 1.9s; animation-delay: 0.2s; }
.speed-line:nth-child(7)  { left: 37%; --angle: -22deg; animation-duration: 1.4s; animation-delay: 0.9s; }
.speed-line:nth-child(8)  { left: 43%; --angle: 28deg;  animation-duration: 1.6s; animation-delay: 0.4s; }
.speed-line:nth-child(9)  { left: 49%; --angle: -14deg; animation-duration: 1.2s; animation-delay: 1.3s; }
.speed-line:nth-child(10) { left: 54%; --angle: 8deg;   animation-duration: 1.7s; animation-delay: 0.6s; }
.speed-line:nth-child(11) { left: 60%; --angle: -28deg; animation-duration: 1.3s; animation-delay: 0.8s; }
.speed-line:nth-child(12) { left: 66%; --angle: 20deg;  animation-duration: 1.5s; animation-delay: 0.2s; }
.speed-line:nth-child(13) { left: 72%; --angle: -16deg; animation-duration: 1.1s; animation-delay: 1.0s; }
.speed-line:nth-child(14) { left: 77%; --angle: 25deg;  animation-duration: 1.9s; animation-delay: 0.5s; }
.speed-line:nth-child(15) { left: 82%; --angle: -10deg; animation-duration: 1.4s; animation-delay: 0.3s; }
.speed-line:nth-child(16) { left: 87%; --angle: 18deg;  animation-duration: 1.6s; animation-delay: 1.2s; }
.speed-line:nth-child(17) { left: 91%; --angle: -24deg; animation-duration: 1.2s; animation-delay: 0.7s; }
.speed-line:nth-child(18) { left: 94%; --angle: 14deg;  animation-duration: 1.8s; animation-delay: 0.4s; }
.speed-line:nth-child(19) { left: 97%; --angle: -30deg; animation-duration: 1.3s; animation-delay: 1.1s; }
.speed-line:nth-child(20) { left: 47%; --angle: 22deg;  animation-duration: 1.5s; animation-delay: 0.0s; }

/* 容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  position: relative;
  z-index: 2;
}

/* ==========================================================================
   导航条
   ========================================================================== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(0, 0, 0, 0.88);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(239, 68, 68, 0.3);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.8);
  padding: 16px 0;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
  font-family: var(--font-heading);
  font-size: 1.35rem;
  letter-spacing: 0.5px;
}

.brand .logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, #EF4444 0%, #FCD34D 100%);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #000;
  box-shadow: 0 0 16px rgba(252, 211, 77, 0.5), 3px 3px 0px #EF4444;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 26px;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 600;
  transition: all 0.2s ease;
  position: relative;
}

.nav-links a:hover {
  color: var(--lightning-yellow);
  text-shadow: 0 0 8px rgba(252, 211, 77, 0.6);
}

/* ==========================================================================
   【CTA 按钮规范】：红到黄对角渐变 + 圆角8px + 30px黄色辉光 + 4px红色硬阴影
   hover 时按钮和阴影都向右下移动 2px
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  text-decoration: none;
  font-family: var(--font-heading);
  font-size: 1rem;
  letter-spacing: 0.5px;
  border-radius: var(--radius-btn);
  padding: 14px 28px;
  cursor: pointer;
  border: none;
  text-align: center;
  transition: transform 0.15s ease, box-shadow 0.15s ease, filter 0.15s ease;
  position: relative;
}

/* 核心 CTA 规范按钮 */
.btn-primary {
  background: linear-gradient(135deg, #EF4444 0%, #FCD34D 100%);
  color: #000000;
  font-weight: 800;
  box-shadow: 4px 4px 0px #EF4444, 0 0 30px rgba(252, 211, 77, 0.6);
}

.btn-primary:hover {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0px #EF4444, 0 0 35px rgba(252, 211, 77, 0.85);
  filter: brightness(1.1);
}

.btn-secondary {
  background: rgba(18, 14, 22, 0.9);
  color: #FFFFFF;
  border: 1px solid rgba(252, 211, 77, 0.4);
  box-shadow: 3px 3px 0px #EF4444;
}

.btn-secondary:hover {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0px #EF4444, 0 0 15px rgba(239, 68, 68, 0.4);
  color: var(--lightning-yellow);
}

.btn-blue {
  background: linear-gradient(135deg, #EF4444 0%, #FCD34D 100%);
  color: #000000;
  font-weight: 800;
  box-shadow: 4px 4px 0px #EF4444, 0 0 30px rgba(252, 211, 77, 0.6);
}

.btn-blue:hover {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0px #EF4444, 0 0 35px rgba(252, 211, 77, 0.85);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.88rem;
  box-shadow: 3px 3px 0px #EF4444, 0 0 20px rgba(252, 211, 77, 0.5);
}

.btn-sm:hover {
  transform: translate(1.5px, 1.5px);
  box-shadow: 1.5px 1.5px 0px #EF4444, 0 0 25px rgba(252, 211, 77, 0.7);
}

.btn-block {
  width: 100%;
}

/* ==========================================================================
   【主视觉区 (Hero Section)】
   左侧：H1「闪电机场」Russo One 粗体 + 4px红+8px黄双层硬阴影 + 简介 + CTA
   右侧：3D速度隧道透视 (5层圆环 Y轴旋转 + 3个发光数据粒子 + 70x120px 放电闪电)
   ========================================================================== */
.hero {
  padding: 80px 0 60px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  align-items: center;
  gap: 40px;
}

.hero-left {
  text-align: left;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(239, 68, 68, 0.15);
  border: 1px solid rgba(252, 211, 77, 0.4);
  padding: 6px 16px;
  border-radius: 999px;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--lightning-yellow);
  box-shadow: 0 0 15px rgba(239, 68, 68, 0.25);
  margin-bottom: 24px;
}

/* H1「闪电机场」使用 Russo One 粗体，4px 红色 + 8px 黄色双层硬阴影投影 */
.hero-title-main {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 3.4rem;
  line-height: 1.15;
  color: #FFFFFF;
  text-shadow: 4px 4px 0px #EF4444, 8px 8px 0px #FCD34D;
  margin-bottom: 12px;
  letter-spacing: 1.5px;
}

.hero-title-sub {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  color: var(--lightning-yellow);
  text-shadow: 0 0 16px rgba(252, 211, 77, 0.5);
  margin-bottom: 20px;
  letter-spacing: 0.5px;
}

.hero-intro {
  background: rgba(14, 10, 18, 0.7);
  border-left: 4px solid var(--primary-red);
  border-top: 1px solid rgba(239, 68, 68, 0.25);
  border-right: 1px solid rgba(252, 211, 77, 0.2);
  border-bottom: 1px solid rgba(252, 211, 77, 0.2);
  padding: 16px 20px;
  border-radius: 0 8px 8px 0;
  margin-bottom: 28px;
}

.hero-subtitle {
  font-size: 1.02rem;
  color: var(--text-muted);
  line-height: 1.75;
}

.hero-subtitle strong {
  color: #FFFFFF;
}

.hero-cta {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-bottom: 38px;
  flex-wrap: wrap;
}

/* 信任数据 */
.hero-badges {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  border-top: 1px solid rgba(239, 68, 68, 0.3);
  padding-top: 26px;
}

.badge-item {
  text-align: left;
}

.badge-value {
  font-family: var(--font-heading);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--lightning-yellow);
  text-shadow: 0 0 12px rgba(252, 211, 77, 0.4);
  margin-bottom: 2px;
}

.badge-label {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ==========================================================================
   【右侧 3D 速度隧道动画】
   5 层圆环（红/黄交替，带辉光，Y轴 360° 旋转 10秒一周期）
   3 个红/黄发光数据流粒子（远端飞向近端/近端飞向远端，1.2-1.8秒）
   70×120px 闪电符号 SVG（黄色填充+白色描边+双层红黄辉光，1.5秒放电）
   ========================================================================== */
.hero-right {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.speed-tunnel-stage {
  width: 380px;
  height: 380px;
  position: relative;
  perspective: 750px;
  transform-style: preserve-3d;
}

/* 隧道旋转核心：在 Y 轴 360° 旋转（10 秒一周期） */
.tunnel-rotator {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  animation: tunnelSpinY 10s linear infinite;
}

@keyframes tunnelSpinY {
  0% {
    transform: rotateY(0deg) rotateX(8deg);
  }
  100% {
    transform: rotateY(360deg) rotateX(8deg);
  }
}

/* 5 层不同大小、不同 Z 轴深度的圆环（红/黄交替，每个带辉光阴影） */
.tunnel-ring {
  position: absolute;
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform-style: preserve-3d;
  box-sizing: border-box;
}

/* Ring 1 (最深远端，红) */
.ring-1 {
  width: 120px;
  height: 120px;
  margin-top: -60px;
  margin-left: -60px;
  transform: translateZ(-160px);
  border: 3px solid #EF4444;
  box-shadow: 0 0 20px #EF4444, inset 0 0 15px rgba(239, 68, 68, 0.6);
}

/* Ring 2 (黄，虚线) */
.ring-2 {
  width: 180px;
  height: 180px;
  margin-top: -90px;
  margin-left: -90px;
  transform: translateZ(-80px);
  border: 3px dashed #FCD34D;
  box-shadow: 0 0 22px #FCD34D, inset 0 0 15px rgba(252, 211, 77, 0.4);
}

/* Ring 3 (中心层，红) */
.ring-3 {
  width: 240px;
  height: 240px;
  margin-top: -120px;
  margin-left: -120px;
  transform: translateZ(0px);
  border: 3px solid #EF4444;
  box-shadow: 0 0 26px #EF4444, inset 0 0 20px rgba(239, 68, 68, 0.5);
}

/* Ring 4 (黄，点线) */
.ring-4 {
  width: 300px;
  height: 300px;
  margin-top: -150px;
  margin-left: -150px;
  transform: translateZ(80px);
  border: 4px dashed #FCD34D;
  box-shadow: 0 0 30px #FCD34D, inset 0 0 20px rgba(252, 211, 77, 0.4);
}

/* Ring 5 (最外近端，红) */
.ring-5 {
  width: 360px;
  height: 360px;
  margin-top: -180px;
  margin-left: -180px;
  transform: translateZ(160px);
  border: 4px solid #EF4444;
  box-shadow: 0 0 36px #EF4444, inset 0 0 25px rgba(239, 68, 68, 0.6);
}

/* 3 个红/黄发光数据流粒子（远端飞向近端 / 近端飞向远端，1.2-1.8 秒，缩放变化模拟透视） */
.tunnel-particle {
  position: absolute;
  top: 50%;
  left: 50%;
  border-radius: 50%;
  transform-style: preserve-3d;
  pointer-events: none;
}

/* 粒子 1：黄光粒子，从远端飞向近端 (1.4s) */
.particle-1 {
  width: 14px;
  height: 14px;
  margin-top: -7px;
  margin-left: -7px;
  background: #FCD34D;
  box-shadow: 0 0 18px #FCD34D, 0 0 30px #EF4444;
  animation: particleFlyFarToNear 1.4s ease-in-out infinite;
}

/* 粒子 2：红光粒子，从近端飞向远端 (1.8s) */
.particle-2 {
  width: 12px;
  height: 12px;
  margin-top: -6px;
  margin-left: -6px;
  background: #EF4444;
  box-shadow: 0 0 18px #EF4444, 0 0 28px #FCD34D;
  animation: particleFlyNearToFar 1.8s ease-in-out infinite 0.4s;
}

/* 粒子 3：红黄复合数据流，从远端飞向近端 (1.2s) */
.particle-3 {
  width: 16px;
  height: 16px;
  margin-top: -8px;
  margin-left: -8px;
  background: linear-gradient(135deg, #FCD34D, #EF4444);
  box-shadow: 0 0 22px #FCD34D, 0 0 36px #EF4444;
  animation: particleFlyFarToNear 1.2s cubic-bezier(0.4, 0, 0.2, 1) infinite 0.7s;
}

@keyframes particleFlyFarToNear {
  0% {
    transform: translateZ(-200px) scale(0.2);
    opacity: 0;
  }
  30% {
    opacity: 1;
  }
  80% {
    opacity: 1;
  }
  100% {
    transform: translateZ(220px) scale(2.2);
    opacity: 0;
  }
}

@keyframes particleFlyNearToFar {
  0% {
    transform: translateZ(200px) scale(2.0);
    opacity: 0;
  }
  30% {
    opacity: 1;
  }
  80% {
    opacity: 1;
  }
  100% {
    transform: translateZ(-220px) scale(0.15);
    opacity: 0;
  }
}

/* 隧道中心叠一个 70×120px 的闪电符号 SVG
   黄色填充 + 白色描边 + 双层红黄辉光，每 1.5 秒触发"放电"动画（缩放 + 透明度变化） */
.tunnel-center-lightning {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 70px;
  height: 120px;
  margin-top: -60px;
  margin-left: -35px;
  z-index: 10;
  transform: translateZ(0);
  pointer-events: none;
  animation: lightningDischarge 1.5s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.tunnel-center-lightning svg {
  width: 100%;
  height: 100%;
  fill: #FCD34D;
  stroke: #FFFFFF;
  stroke-width: 2.5px;
  stroke-linejoin: round;
  /* 双层红黄辉光 */
  filter: drop-shadow(0 0 10px #FCD34D) drop-shadow(0 0 25px #EF4444);
}

@keyframes lightningDischarge {
  0%, 75%, 100% {
    transform: scale(1);
    opacity: 0.9;
    filter: drop-shadow(0 0 10px #FCD34D) drop-shadow(0 0 22px #EF4444);
  }
  80% {
    transform: scale(1.28);
    opacity: 1;
    filter: drop-shadow(0 0 25px #FFFFFF) drop-shadow(0 0 45px #FCD34D) drop-shadow(0 0 70px #EF4444);
  }
  86% {
    transform: scale(0.92);
    opacity: 0.6;
    filter: drop-shadow(0 0 5px #FCD34D);
  }
  92% {
    transform: scale(1.18);
    opacity: 1;
    filter: drop-shadow(0 0 28px #FFFFFF) drop-shadow(0 0 50px #FCD34D);
  }
}

/* ==========================================================================
   模块通用标题与排版
   ========================================================================== */
.section {
  padding: 85px 0;
  position: relative;
  z-index: 2;
}

.section-alt {
  background: rgba(10, 6, 14, 0.7);
  border-top: 1px solid rgba(239, 68, 68, 0.25);
  border-bottom: 1px solid rgba(252, 211, 77, 0.2);
}

.section-header {
  text-align: center;
  margin-bottom: 54px;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-heading);
  color: var(--lightning-yellow);
  font-size: 0.88rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 10px;
  text-shadow: 0 0 10px rgba(252, 211, 77, 0.5);
}

.section-title {
  font-family: var(--font-heading);
  font-size: 2.3rem;
  font-weight: 700;
  letter-spacing: 1px;
  color: #FFFFFF;
  text-shadow: 2px 2px 0px #EF4444, 4px 4px 0px rgba(252, 211, 77, 0.6);
  margin-bottom: 14px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto;
}

/* ==========================================================================
   产品核心优势介绍 (3个图文卡片)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 36px 28px;
  transition: all 0.25s ease;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, #EF4444, #FCD34D);
  opacity: 0.5;
}

.feature-card:hover {
  transform: translateY(-6px);
  background: var(--bg-card-hover);
  border-color: rgba(252, 211, 77, 0.5);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.9), 0 0 25px rgba(239, 68, 68, 0.25);
}

.feature-icon-wrapper {
  width: 58px;
  height: 58px;
  border-radius: 8px;
  background: rgba(239, 68, 68, 0.15);
  border: 1px solid rgba(239, 68, 68, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: var(--primary-red);
  box-shadow: 0 0 15px rgba(239, 68, 68, 0.3);
}

.feature-icon-wrapper.icon-orange {
  background: rgba(252, 211, 77, 0.15);
  border-color: rgba(252, 211, 77, 0.4);
  color: var(--lightning-yellow);
  box-shadow: 0 0 15px rgba(252, 211, 77, 0.3);
}

.feature-icon-wrapper.icon-purple {
  background: linear-gradient(135deg, rgba(239, 68, 68, 0.2), rgba(252, 211, 77, 0.2));
  border-color: rgba(252, 211, 77, 0.4);
  color: #FFFFFF;
}

.feature-title {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  margin-bottom: 12px;
  color: #FFFFFF;
}

.feature-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.feature-bullets {
  list-style: none;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 16px;
}

.feature-bullets li {
  font-size: 0.88rem;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.feature-bullets li span.check {
  color: var(--lightning-yellow);
  font-weight: bold;
}

/* ==========================================================================
   流媒体与 AI 支持图卡
   ========================================================================== */
.unlock-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
}

.unlock-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 36px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.7);
}

.unlock-box-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.unlock-box-header h3 {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  color: #FFFFFF;
}

.unlock-box-header .tag {
  background: rgba(252, 211, 77, 0.15);
  color: var(--lightning-yellow);
  border: 1px solid rgba(252, 211, 77, 0.35);
  font-size: 0.78rem;
  padding: 3px 10px;
  border-radius: 999px;
  font-weight: 700;
}

.unlock-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin-top: 24px;
}

.unlock-item {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(239, 68, 68, 0.2);
  border-radius: 8px;
  padding: 14px 10px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  transition: all 0.2s ease;
}

.unlock-item:hover {
  border-color: var(--lightning-yellow);
  background: rgba(252, 211, 77, 0.08);
  box-shadow: 0 0 15px rgba(252, 211, 77, 0.2);
  transform: translateY(-2px);
}

.unlock-item-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.9rem;
}

.unlock-item-name {
  font-size: 0.9rem;
  font-weight: 700;
  color: #FFFFFF;
}

.unlock-item-sub {
  font-size: 0.75rem;
  color: var(--text-dim);
}

/* ==========================================================================
   套餐价格对比表
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 40px 30px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
}

.pricing-card:hover {
  transform: translateY(-6px);
  border-color: rgba(252, 211, 77, 0.4);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.8), 0 0 25px rgba(239, 68, 68, 0.3);
}

.pricing-card.featured {
  background: linear-gradient(180deg, rgba(239, 68, 68, 0.16) 0%, rgba(12, 10, 16, 0.95) 100%);
  border: 2px solid var(--lightning-yellow);
  box-shadow: 0 0 35px rgba(239, 68, 68, 0.3), 0 0 20px rgba(252, 211, 77, 0.25);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #EF4444 0%, #FCD34D 100%);
  color: #000;
  font-family: var(--font-heading);
  font-size: 0.82rem;
  font-weight: 800;
  padding: 4px 18px;
  border-radius: 999px;
  letter-spacing: 0.5px;
  box-shadow: 0 4px 15px rgba(252, 211, 77, 0.5), 2px 2px 0px #EF4444;
}

.plan-name {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: #FFFFFF;
}

.plan-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 24px;
  min-height: 42px;
}

.price-wrapper {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.currency {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  color: var(--lightning-yellow);
}

.price {
  font-family: var(--font-heading);
  font-size: 3.2rem;
  font-weight: 700;
  color: #FFFFFF;
  letter-spacing: -1px;
  text-shadow: 2px 2px 0px #EF4444;
}

.period {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.billing-cycle {
  display: block;
  font-size: 0.82rem;
  color: var(--lightning-yellow);
  background: rgba(252, 211, 77, 0.1);
  border: 1px solid rgba(252, 211, 77, 0.3);
  padding: 5px 10px;
  border-radius: 6px;
  margin-bottom: 22px;
  text-align: center;
  font-weight: 600;
}

.plan-features {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}

.plan-features li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.plan-features li svg {
  flex-shrink: 0;
  margin-top: 3px;
  color: var(--lightning-yellow);
}

.plan-features li strong {
  color: var(--text-main);
}

/* ==========================================================================
   用户评价
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 30px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-stars {
  color: var(--lightning-yellow);
  margin-bottom: 14px;
  letter-spacing: 2px;
  text-shadow: 0 0 10px rgba(252, 211, 77, 0.5);
}

.review-text {
  font-size: 0.95rem;
  color: #e2e8f0;
  line-height: 1.7;
  margin-bottom: 20px;
  font-style: italic;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, #EF4444, #FCD34D);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: bold;
  font-size: 1rem;
  color: #000;
  box-shadow: 2px 2px 0px #EF4444;
}

.author-info h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: #FFFFFF;
}

.author-info p {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ==========================================================================
   常见问题解答 (FAQ)
   ========================================================================== */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

details.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 20px 24px;
  transition: all 0.25s ease;
}

details.faq-item[open] {
  border-color: var(--lightning-yellow);
  background: rgba(18, 12, 24, 0.95);
  box-shadow: 0 0 20px rgba(239, 68, 68, 0.2);
}

summary.faq-question {
  list-style: none;
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
  color: #FFFFFF;
}

summary.faq-question::-webkit-details-marker {
  display: none;
}

summary.faq-question::after {
  content: "+";
  font-size: 1.5rem;
  font-weight: 300;
  color: var(--lightning-yellow);
  transition: transform 0.2s ease;
}

details.faq-item[open] summary.faq-question::after {
  content: "−";
  color: var(--primary-red);
}

.faq-answer {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 页底呼吁性 Banner */
.final-cta {
  background: linear-gradient(135deg, rgba(239, 68, 68, 0.25) 0%, rgba(252, 211, 77, 0.15) 100%);
  border: 2px solid rgba(252, 211, 77, 0.4);
  border-radius: 16px;
  padding: 55px 40px;
  text-align: center;
  margin-top: 60px;
  box-shadow: 0 0 35px rgba(239, 68, 68, 0.3);
}

.final-cta h2 {
  font-family: var(--font-heading);
  font-size: 2.2rem;
  margin-bottom: 14px;
  color: #FFFFFF;
  text-shadow: 3px 3px 0px #EF4444;
}

.final-cta p {
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto 30px;
}

/* ==========================================================================
   规范页脚：只保留 4 个标题，并在新页面中展示
   ========================================================================== */
.footer {
  background: #020202;
  border-top: 1px solid rgba(239, 68, 68, 0.3);
  padding: 50px 0 35px;
  margin-top: 80px;
  position: relative;
  z-index: 2;
}

.footer-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 36px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.footer-nav-link {
  color: #cbd5e1;
  text-decoration: none;
  font-family: var(--font-heading);
  font-size: 1.05rem;
  letter-spacing: 0.5px;
  transition: all 0.2s ease;
  position: relative;
  padding: 6px 12px;
}

.footer-nav-link:hover {
  color: var(--lightning-yellow);
  text-shadow: 0 0 10px rgba(252, 211, 77, 0.7);
}

.footer-copy {
  text-align: center;
  color: var(--text-dim);
  font-size: 0.85rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 24px;
}

/* ==========================================================================
   子页面通用样式
   ========================================================================== */
.subpage-header {
  padding: 60px 0 40px;
  text-align: center;
  border-bottom: 1px solid rgba(239, 68, 68, 0.3);
  background: rgba(14, 10, 18, 0.5);
  position: relative;
  z-index: 2;
}

.subpage-title {
  font-family: var(--font-heading);
  font-size: 2.6rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #FFFFFF;
  text-shadow: 3px 3px 0px #EF4444, 6px 6px 0px var(--lightning-yellow);
}

.subpage-content {
  padding: 60px 0;
  max-width: 880px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
}

.article-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 45px;
  line-height: 1.8;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.8);
}

.article-box h2 {
  font-family: var(--font-heading);
  font-size: 1.55rem;
  margin: 32px 0 16px;
  color: #FFFFFF;
  border-left: 4px solid var(--primary-red);
  padding-left: 12px;
}

.article-box h2:first-of-type {
  margin-top: 0;
}

.article-box h3 {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  margin: 20px 0 10px;
  color: var(--lightning-yellow);
}

.article-box p {
  color: var(--text-muted);
  margin-bottom: 16px;
  font-size: 0.98rem;
}

.article-box ul, .article-box ol {
  color: var(--text-muted);
  margin-left: 24px;
  margin-bottom: 20px;
  font-size: 0.96rem;
}

.article-box li {
  margin-bottom: 8px;
}

.article-box .alert-box {
  background: rgba(239, 68, 68, 0.12);
  border: 1px solid rgba(252, 211, 77, 0.4);
  border-radius: 8px;
  padding: 16px 20px;
  margin: 24px 0;
  color: var(--lightning-yellow);
  font-size: 0.95rem;
}

.sitemap-group {
  margin-bottom: 36px;
}

.sitemap-links {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 14px;
}

.sitemap-card {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(239, 68, 68, 0.25);
  padding: 18px 22px;
  border-radius: 8px;
  text-decoration: none;
  color: var(--text-main);
  display: block;
  transition: all 0.2s ease;
}

.sitemap-card:hover {
  background: rgba(252, 211, 77, 0.08);
  border-color: var(--lightning-yellow);
  box-shadow: 0 0 15px rgba(252, 211, 77, 0.25);
}

.sitemap-card-title {
  font-family: var(--font-heading);
  font-size: 1.05rem;
  margin-bottom: 4px;
  color: #FFFFFF;
}

.sitemap-card-desc {
  font-size: 0.85rem;
  color: var(--text-dim);
}

/* ==========================================================================
   知识科普 SEO 9 篇专栏文章与目录索引样式
   ========================================================================== */
.seo-toc-container {
  background: var(--bg-card);
  border: 1px solid rgba(252, 211, 77, 0.35);
  border-radius: 14px;
  padding: 30px;
  margin-bottom: 50px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8), 0 0 20px rgba(239, 68, 68, 0.2);
}

.seo-toc-title {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  color: var(--lightning-yellow);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.seo-toc-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}

.seo-toc-item {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(239, 68, 68, 0.25);
  border-radius: 8px;
  padding: 12px 14px;
  text-decoration: none;
  color: #FFFFFF;
  font-size: 0.9rem;
  font-weight: 600;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  transition: all 0.2s ease;
  line-height: 1.45;
}

.seo-toc-item:hover {
  background: rgba(252, 211, 77, 0.1);
  border-color: var(--lightning-yellow);
  color: var(--lightning-yellow);
  transform: translateY(-2px);
}

.seo-toc-num {
  font-family: var(--font-heading);
  color: var(--primary-red);
  font-size: 0.85rem;
  flex-shrink: 0;
  margin-top: 1px;
}

.seo-article-card {
  background: var(--bg-card);
  border: 1px solid rgba(239, 68, 68, 0.28);
  border-radius: 14px;
  padding: 42px 38px;
  margin-bottom: 45px;
  box-shadow: 0 12px 35px rgba(0, 0, 0, 0.85);
  position: relative;
  overflow: hidden;
}

.seo-article-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, #EF4444, #FCD34D);
}

.seo-article-header {
  margin-bottom: 24px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  padding-bottom: 20px;
}

.seo-article-title {
  font-family: var(--font-heading);
  font-size: 1.7rem;
  color: #FFFFFF;
  line-height: 1.35;
  margin: 10px 0 14px;
  text-shadow: 1px 1px 0px #EF4444;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-dim);
  flex-wrap: wrap;
}

.article-tag-badge {
  background: rgba(239, 68, 68, 0.2);
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.4);
  padding: 2px 10px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.78rem;
}

.word-count-badge {
  background: rgba(252, 211, 77, 0.15);
  color: var(--lightning-yellow);
  border: 1px solid rgba(252, 211, 77, 0.35);
  padding: 2px 10px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.78rem;
}

.seo-article-body {
  font-size: 1rem;
  line-height: 1.85;
  color: #e2e8f0;
}

.seo-article-body h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  color: var(--lightning-yellow);
  margin: 26px 0 12px;
}

.seo-article-body p {
  margin-bottom: 16px;
  color: var(--text-muted);
}

.seo-article-body ul, .seo-article-body ol {
  margin: 14px 0 20px 24px;
  color: var(--text-muted);
}

.seo-article-body li {
  margin-bottom: 8px;
}

.seo-article-body strong {
  color: #FFFFFF;
}

/* 官网首页专用高亮内链 */
.home-internal-link {
  color: var(--lightning-yellow);
  text-decoration: underline;
  text-underline-offset: 4px;
  font-weight: 700;
  transition: all 0.2s ease;
  padding: 2px 4px;
  border-radius: 4px;
}

.home-internal-link:hover {
  background: rgba(252, 211, 77, 0.18);
  color: #FFFFFF;
  text-shadow: 0 0 8px rgba(252, 211, 77, 0.8);
}

.article-bottom-cta {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.article-keywords-list {
  font-size: 0.82rem;
  color: var(--text-dim);
}

.article-keywords-list span {
  color: rgba(252, 211, 77, 0.8);
  margin-right: 6px;
}

/* 每篇文章专属 FAQ 样式 */
.article-faq-container {
  margin-top: 26px;
  background: rgba(0, 0, 0, 0.45);
  border: 1px solid rgba(252, 211, 77, 0.25);
  border-radius: 10px;
  padding: 22px 20px;
}

.article-faq-header {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  color: var(--lightning-yellow);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.article-faq-item {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(239, 68, 68, 0.2);
  border-radius: 8px;
  margin-bottom: 10px;
  padding: 14px 18px;
  transition: all 0.2s ease;
}

.article-faq-item[open] {
  border-color: var(--lightning-yellow);
  background: rgba(239, 68, 68, 0.08);
}

.article-faq-question {
  list-style: none;
  font-family: var(--font-heading);
  font-size: 0.98rem;
  font-weight: 700;
  cursor: pointer;
  color: #FFFFFF;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.article-faq-question::-webkit-details-marker {
  display: none;
}

.article-faq-question::after {
  content: "+";
  font-size: 1.3rem;
  color: var(--lightning-yellow);
  transition: transform 0.2s ease;
}

.article-faq-item[open] .article-faq-question::after {
  content: "−";
  color: var(--primary-red);
}

.article-faq-answer {
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 篇章之间网状互链栏 */
.article-cross-links {
  margin-top: 22px;
  padding: 14px 18px;
  background: rgba(239, 68, 68, 0.08);
  border-left: 3px solid var(--lightning-yellow);
  border-radius: 0 8px 8px 0;
  font-size: 0.88rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.article-cross-links a {
  color: var(--lightning-yellow);
  text-decoration: none;
  font-weight: 600;
  transition: color 0.2s ease;
}

.article-cross-links a:hover {
  text-decoration: underline;
  color: #FFFFFF;
}

/* ==========================================================================
   响应式媒体查询 (@media)
   确保手机端完美单栏自适应与流畅触控
   ========================================================================== */
@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  
  .hero-right {
    order: -1; /* 移动端隧道在上，视觉冲击先行 */
  }
  
  .speed-tunnel-stage {
    width: 320px;
    height: 320px;
  }
  
  .hero-title-main {
    font-size: 2.8rem;
  }
  
  .features-grid,
  .pricing-grid,
  .reviews-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .unlock-wrapper {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .seo-toc-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .hero {
    padding: 40px 0 30px;
  }
  
  .hero-title-main {
    font-size: 2.2rem;
    text-shadow: 3px 3px 0px #EF4444, 6px 6px 0px #FCD34D;
  }
  
  .hero-title-sub {
    font-size: 1.25rem;
  }
  
  .hero-cta {
    flex-direction: column;
    width: 100%;
    gap: 14px;
  }
  
  .hero-cta .btn {
    width: 100%;
    padding: 15px 20px;
  }
  
  .hero-badges {
    grid-template-columns: repeat(2, 1fr);
    gap: 18px 12px;
  }
  
  .section {
    padding: 50px 0;
  }
  
  .section-title {
    font-size: 1.8rem;
  }
  
  .unlock-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .article-box {
    padding: 24px 18px;
  }
  
  .footer-nav {
    flex-direction: column;
    gap: 16px;
  }
  
  .sitemap-links {
    grid-template-columns: 1fr;
  }
  
  .seo-toc-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .speed-tunnel-stage {
    width: 270px;
    height: 270px;
  }
  
  .hero-title-main {
    font-size: 1.85rem;
  }
  
  .pricing-card {
    padding: 30px 18px;
  }
  
  .price {
    font-size: 2.7rem;
  }
}

/* 移动端 44x44px 最小安全触摸热区 */
@media (max-width: 768px) {
  .btn,
  .nav-links a,
  .footer-nav-link,
  .seo-toc-item,
  .article-faq-question {
    min-height: 44px;
    display: inline-flex;
    align-items: center;
  }
}

/* 前庭功能减弱动效偏好规范 (prefers-reduced-motion) */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  
  .speed-line,
  .perspective-grid-inner,
  .tunnel-rotator,
  .tunnel-ring,
  .tunnel-particle,
  .lightning-center {
    animation: none !important;
  }
}