/* ============================================
   System Demo Section
   外层圆角白卡 + 3 区结构（上白 / 中淡蓝 / 下白）
   遵守 7 条铁律：浅色 / clamp 字号 / iOS 兼容
   ============================================ */

#section-system.home-section {
  position: relative;
  width: 100%;
  padding: clamp(80px, 8vw, 160px) 0;
  background: var(--bg);
  color: var(--text);
  overflow: hidden;
}

.system-demo__inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 clamp(24px, 4vw, 80px);
}

/* ---- 外层大白卡 ---- */

.system-demo__card {
  position: relative;
  width: 100%;
  background: #FFFFFF;
  border: 1px solid rgba(10, 20, 40, .06);
  border-radius: clamp(20px, 1.8vw, 32px);
  box-shadow: 0 20px 60px rgba(10, 20, 40, .08);
  overflow: hidden;
  transform: translate3d(0, 0, 0);
  will-change: transform;
}

/* ---- 上区：标题 ---- */

.system-demo__head {
  padding: clamp(36px, 3.6vw, 64px) clamp(32px, 3.4vw, 64px) clamp(28px, 2.6vw, 48px);
  background: #FFFFFF;
}

.system-demo__title {
  margin: 0 0 clamp(12px, 1.2vw, 20px);
  font-size: clamp(26px, 3vw, 48px);
  font-weight: 600;
  line-height: 1.2;
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  letter-spacing: -0.01em;
}

.system-demo__subtitle {
  margin: 0;
  font-size: clamp(14px, 1.05vw, 18px);
  font-weight: 500;
  color: rgba(10, 20, 40, .55);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ---- 中区：浅蓝淡彩 + 图片 + 箭头 ---- */

.system-demo__stage {
  position: relative;
  background: linear-gradient(135deg, #EFF6FF 0%, #DBEAFE 100%);
  padding: clamp(40px, 4vw, 80px) clamp(40px, 4vw, 80px);
}

.system-demo__slide-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 1024 / 686;
  border-radius: clamp(8px, .8vw, 14px);
  overflow: hidden;
  background: #FFFFFF;
  box-shadow: 0 8px 24px rgba(10, 20, 40, .10);
}

.system-demo__track {
  display: flex;
  width: 500%;
  height: 100%;
  transform: translate3d(0, 0, 0);
  transition: transform .65s var(--ease);
  will-change: transform;
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}

.system-demo__slide {
  width: calc(100% / 5);
  height: 100%;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.system-demo__slide img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  display: block;
}

/* ---- 中区左右悬浮箭头 ---- */

.system-demo__nav {
  position: absolute;
  top: 50%;
  z-index: 5;
  width: clamp(40px, 3.4vw, 56px);
  height: clamp(40px, 3.4vw, 56px);
  border-radius: 50%;
  border: 1px solid rgba(10, 20, 40, .06);
  background: rgba(255, 255, 255, .9);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  color: var(--text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  box-shadow: 0 4px 14px rgba(10, 20, 40, .08);
  transform: translate3d(0, -50%, 0);
  transition:
    background .3s var(--ease),
    color .3s var(--ease),
    border-color .3s var(--ease),
    transform .3s var(--ease),
    box-shadow .3s var(--ease);
  -webkit-tap-highlight-color: transparent;
}

.system-demo__nav--prev {
  left: clamp(12px, 1.4vw, 28px);
}

.system-demo__nav--next {
  right: clamp(12px, 1.4vw, 28px);
}

.system-demo__nav svg {
  width: clamp(18px, 1.4vw, 24px);
  height: clamp(18px, 1.4vw, 24px);
  pointer-events: none;
}

@media (hover: hover) {
  .system-demo__nav:hover {
    background: var(--text);
    color: #FFFFFF;
    border-color: var(--text);
    transform: translate3d(0, -50%, 0) scale(1.05);
    box-shadow: 0 6px 20px rgba(10, 20, 40, .15);
  }
}

.system-demo__nav:active {
  transform: translate3d(0, -50%, 0) scale(0.94);
}

/* ---- 下区：caption + dots ---- */

.system-demo__footer {
  padding: clamp(28px, 2.6vw, 48px) clamp(32px, 3.4vw, 64px) clamp(36px, 3.6vw, 64px);
  background: #FFFFFF;
  display: flex;
  flex-direction: column;
  gap: clamp(20px, 2vw, 32px);
}

.system-demo__captions {
  position: relative;
  min-height: clamp(64px, 5.6vw, 88px);
  width: 100%;
}

.system-demo__caption {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: clamp(6px, .6vw, 12px);
  opacity: 0;
  transform: translate3d(0, 6px, 0);
  transition:
    opacity .45s var(--ease),
    transform .45s var(--ease);
  pointer-events: none;
}

.system-demo__caption.is-active {
  opacity: 1;
  transform: translate3d(0, 0, 0);
  pointer-events: auto;
}

.system-demo__caption h3 {
  margin: 0;
  font-size: clamp(20px, 2vw, 30px);
  font-weight: 600;
  color: var(--text);
  line-height: 1.25;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.system-demo__caption p {
  margin: 0;
  font-size: clamp(14px, 1vw, 17px);
  font-weight: 500;
  color: rgba(10, 20, 40, .55);
  line-height: 1.5;
}

.system-demo__dots {
  display: flex;
  gap: clamp(8px, .8vw, 14px);
}

.system-demo__dot {
  width: clamp(8px, .7vw, 12px);
  height: clamp(8px, .7vw, 12px);
  border-radius: 50%;
  border: none;
  background: rgba(10, 20, 40, .15);
  cursor: pointer;
  padding: 0;
  transition:
    background .3s var(--ease),
    transform .3s var(--ease);
  -webkit-tap-highlight-color: transparent;
}

.system-demo__dot.is-active {
  background: var(--accent);
  transform: scale(1.3);
}

@media (hover: hover) {
  .system-demo__dot:hover {
    background: rgba(56, 189, 248, .6);
  }
}

/* ---- SP 端 ---- */

@media (max-width: 767px) {
  .system-demo__head {
    padding: clamp(24px, 6vw, 36px) clamp(20px, 5vw, 28px) clamp(20px, 5vw, 28px);
  }

  .system-demo__title {
    font-size: clamp(22px, 6vw, 28px);
  }

  .system-demo__subtitle {
    font-size: clamp(13px, 3.6vw, 15px);
  }

  .system-demo__stage {
    padding: clamp(24px, 5vw, 36px) clamp(20px, 5vw, 32px);
  }

  .system-demo__nav {
    width: 36px;
    height: 36px;
  }

  .system-demo__nav--prev { left: 8px; }
  .system-demo__nav--next { right: 8px; }

  .system-demo__footer {
    padding: clamp(20px, 5vw, 28px) clamp(20px, 5vw, 28px) clamp(28px, 6vw, 36px);
    gap: clamp(16px, 4vw, 22px);
  }

  .system-demo__caption h3 {
    font-size: clamp(18px, 5vw, 22px);
  }

  .system-demo__caption p {
    font-size: clamp(13px, 3.6vw, 15px);
  }

  .system-demo__captions {
    min-height: clamp(58px, 14vw, 76px);
  }
}