:root {
  color-scheme: light;
  --ink: #17202a;
  --muted: #5f6b7a;
  --line: #d9e1e8;
  --soft: #f4f8fb;
  --blue: #2f78b7;
  --red: #d94a45;
  --green: #2e8b57;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: #fff;
  color: var(--ink);
  font-family: "Microsoft YaHei", "Hiragino Sans GB", Arial, sans-serif;
}

a {
  color: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px clamp(18px, 5vw, 72px);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
}

.brand,
.site-header nav {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand {
  font-size: 20px;
  font-weight: 800;
  text-decoration: none;
}

.brand img {
  border-radius: 8px;
}

.site-header nav a {
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

.hero {
  min-height: 76vh;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(420px, 1.35fr);
  gap: clamp(28px, 6vw, 72px);
  align-items: center;
  padding: clamp(36px, 7vw, 88px) clamp(18px, 6vw, 86px);
  background: linear-gradient(180deg, #f7fbff 0%, #fff 78%);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--green);
  font-size: 13px;
  font-weight: 800;
}

h1,
h2 {
  margin: 0;
  letter-spacing: 0;
}

h1 {
  font-size: clamp(42px, 8vw, 88px);
  line-height: 0.95;
}

h2 {
  font-size: 30px;
  line-height: 1.2;
}

.intro {
  max-width: 680px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.primary-link,
.secondary-link {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 11px 18px;
  border-radius: 6px;
  font-weight: 800;
  text-decoration: none;
}

.primary-link {
  background: var(--blue);
  color: #fff;
}

.secondary-link {
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
}

.hero-media,
.feature-media {
  display: flex;
  justify-content: center;
}

.hero-media.slider {
  position: relative;
  align-items: center;
  width: 100%;
}

.hero-media.slider .slider-track {
  position: relative;
  width: 100%;
  max-width: 1280px;
  min-height: 440px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: #fff;
  box-shadow: 0 18px 50px rgba(22, 34, 48, 0.14);
}

.hero-media.slider .slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transform: scale(0.98);
  transition: opacity 0.45s ease, transform 0.45s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-media.slider .slide.active {
  opacity: 1;
  transform: scale(1);
  z-index: 1;
}

.hero-media.slider img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: contain;
  border-radius: 18px;
}

.slider-dots {
  position: absolute;
  left: 50%;
  bottom: 18px;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
  z-index: 2;
}

.slider-dots .dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 1px solid rgba(23, 35, 46, 0.18);
  background: rgba(255, 255, 255, 0.75);
  cursor: pointer;
  transition: transform 0.25s ease, background 0.25s ease;
}

.slider-dots .dot.active {
  transform: scale(1.15);
  background: var(--blue);
}

.hero-media img,
.feature-media img {
  max-width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 18px 50px rgba(22, 34, 48, 0.14);
}

.section-band,
.feature-grid,
.modes {
  padding: clamp(36px, 6vw, 76px) clamp(18px, 6vw, 86px);
}

.section-band {
  background: var(--soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.install-image {
  margin-top: 24px;
  display: flex;
  justify-content: center;
}

.install-image img {
  max-width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: 0 18px 50px rgba(22, 34, 48, 0.14);
}

.section-head {
  max-width: 760px;
  margin-bottom: 24px;
}

.steps,
.mode-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.steps article,
.mode-list article {
  min-height: 150px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.steps strong,
.mode-list span {
  display: block;
  color: var(--ink);
  font-size: 18px;
  font-weight: 800;
}

.steps p,
.mode-list p,
.feature-copy li {
  color: var(--muted);
  line-height: 1.75;
}

.feature-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 420px);
  gap: clamp(26px, 5vw, 64px);
  align-items: center;
}

.feature-copy ul {
  margin: 22px 0 0;
  padding-left: 20px;
}

.feature-copy li + li {
  margin-top: 10px;
}

.modes h2 {
  margin-bottom: 22px;
}

.mode-list span {
  color: var(--red);
}

@media (max-width: 820px) {
  .site-header {
    position: static;
    align-items: flex-start;
    flex-direction: column;
  }

  .site-header nav {
    flex-wrap: wrap;
  }

  .hero,
  .feature-grid,
  .steps,
  .mode-list {
    grid-template-columns: 1fr;
  }

  h1 {
    font-size: 48px;
  }
}