:root {
  --black: #111111;
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --line: #d8d8dc;
  --soft: #f5f5f7;
  --white: #ffffff;
  --blue: #0071e3;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  background: var(--white);
}

a {
  color: inherit;
  text-decoration: none;
}

.header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
  padding: 0 clamp(20px, 5vw, 72px);
  background: rgba(255, 255, 255, .82);
  border-bottom: 1px solid rgba(0, 0, 0, .08);
  backdrop-filter: saturate(180%) blur(20px);
}

.brand,
.nav {
  display: flex;
  align-items: center;
}

.brand {
  gap: 10px;
  font-size: 15px;
  font-weight: 700;
}

.brand-dot {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: linear-gradient(135deg, #111, #777);
}

.nav {
  gap: 34px;
  color: #424245;
  font-size: 13px;
}

.nav a:hover {
  color: var(--blue);
}

.menu-btn {
  display: none;
  width: 40px;
  height: 40px;
  border: 0;
  background: transparent;
}

.menu-btn span {
  display: block;
  width: 18px;
  height: 1.5px;
  margin: 6px auto;
  background: var(--ink);
}

.hero {
  min-height: calc(100vh - 56px);
  padding: clamp(60px, 9vw, 104px) clamp(20px, 7vw, 96px) 56px;
  text-align: center;
  overflow: hidden;
  background: linear-gradient(180deg, #fbfbfd 0%, #f5f5f7 100%);
}

.overline {
  margin: 0 0 14px;
  color: var(--blue);
  font-size: 13px;
  font-weight: 700;
}

.center {
  text-align: center;
}

.hero h1,
.section h2 {
  max-width: 980px;
  margin: 0 auto;
  font-size: clamp(42px, 6.8vw, 86px);
  line-height: 1.04;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 760px;
  margin: 22px auto 28px;
  color: var(--muted);
  font-size: clamp(19px, 2vw, 25px);
  line-height: 1.55;
}

.hero-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 24px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 700;
  cursor: pointer;
}

.btn.dark {
  color: var(--white);
  background: var(--blue);
}

.btn.light {
  color: var(--blue);
  border-color: var(--blue);
}

.btn.full {
  width: 100%;
  border-radius: 12px;
}

.hero-image {
  display: block;
  width: min(1120px, 118%);
  margin: clamp(32px, 6vw, 70px) auto 0;
  filter: drop-shadow(0 36px 54px rgba(0, 0, 0, .15));
}

.section {
  padding: clamp(76px, 10vw, 124px) clamp(20px, 7vw, 96px);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
  gap: clamp(36px, 7vw, 90px);
  align-items: start;
}

.section h2 {
  font-size: clamp(34px, 5vw, 64px);
}

.text-block p,
.contact-copy p {
  margin: 0;
  color: var(--muted);
  font-size: 21px;
  line-height: 1.7;
}

.mini-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-top: 34px;
}

.mini-grid article,
.product-card,
.company-grid div,
.form {
  border-radius: 18px;
  background: var(--soft);
}

.mini-grid article {
  display: grid;
  gap: 10px;
  padding: 24px;
}

.mini-grid span,
.product-card p,
.promise-list span,
.company-grid span {
  color: var(--muted);
  line-height: 1.65;
}

.products {
  background: var(--black);
  color: var(--white);
}

.products h2 {
  color: var(--white);
  text-align: center;
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
  margin-top: 42px;
}

.product-card {
  min-height: 370px;
  padding: 24px;
  color: var(--ink);
  overflow: hidden;
}

.product-visual {
  display: block;
  width: 100%;
  height: 190px;
  margin-bottom: 20px;
  border-radius: 18px;
  background: radial-gradient(circle at 50% 42%, #fff, #d9d9df 62%, #b7b7bf);
  position: relative;
}

.product-visual::before,
.product-visual::after {
  content: "";
  position: absolute;
  border-radius: 999px;
  background: #1d1d1f;
  opacity: .82;
}

.cable::before { width: 130px; height: 12px; top: 88px; left: 22%; transform: rotate(-28deg); }
.cable::after { width: 44px; height: 20px; top: 72px; right: 24%; }
.power::before { width: 116px; height: 68px; top: 62px; left: 26%; border-radius: 18px; }
.power::after { width: 34px; height: 8px; top: 92px; left: 40%; background: #f5f5f7; }
.stand::before { width: 92px; height: 120px; top: 34px; left: 34%; border-radius: 20px; transform: rotate(7deg); }
.stand::after { width: 116px; height: 12px; top: 146px; left: 25%; }
.audio::before { width: 90px; height: 58px; top: 74px; left: 34%; border-radius: 28px; }
.audio::after { width: 18px; height: 18px; top: 95px; left: 47%; background: #f5f5f7; }

.product-card h3 {
  margin: 0 0 10px;
  font-size: 24px;
}

.product-card p {
  margin: 0;
}

.promise {
  background: var(--soft);
}

.promise-panel {
  max-width: 1120px;
  margin: 0 auto;
  padding: clamp(42px, 7vw, 74px);
  border-radius: 28px;
  color: var(--white);
  background: linear-gradient(145deg, #151515, #2d2d30);
}

.promise-panel h2 {
  margin-left: 0;
}

.promise-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 42px;
}

.promise-list div {
  display: grid;
  gap: 10px;
  padding: 24px;
  border-radius: 18px;
  background: rgba(255, 255, 255, .08);
}

.promise-list span {
  color: rgba(255, 255, 255, .7);
}

.company {
  text-align: center;
}

.company-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  margin-top: 38px;
  text-align: left;
}

.company-grid div {
  display: grid;
  gap: 10px;
  padding: 24px;
}

.company-grid strong {
  font-size: 17px;
  line-height: 1.5;
  word-break: break-word;
}

.contact {
  display: grid;
  grid-template-columns: minmax(0, .85fr) minmax(340px, .65fr);
  gap: clamp(34px, 7vw, 86px);
  align-items: start;
  background: #fbfbfd;
}

.form {
  display: grid;
  gap: 18px;
  padding: 28px;
}

.form label {
  display: grid;
  gap: 8px;
  font-weight: 700;
}

.form input,
.form textarea,
.form select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 14px 15px;
  color: var(--ink);
  font: inherit;
  background: var(--white);
  outline: none;
}

.form input:focus,
.form textarea:focus,
.form select:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 4px rgba(0, 113, 227, .12);
}

.form-tip {
  min-height: 22px;
  margin: 0;
  color: var(--blue);
}

.footer {
  display: flex;
  justify-content: space-between;
  gap: 22px;
  padding: 34px clamp(20px, 7vw, 96px);
  color: #a1a1a6;
  background: var(--black);
}

.footer strong {
  display: block;
  margin-bottom: 8px;
  color: var(--white);
}

.footer p {
  margin: 0;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 18px;
}

.footer a:hover {
  color: var(--white);
}

@media (max-width: 1060px) {
  .product-grid,
  .company-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .mini-grid,
  .promise-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .menu-btn {
    display: block;
  }

  .nav {
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    display: none;
    padding: 10px 20px 20px;
    background: rgba(255, 255, 255, .96);
    border-bottom: 1px solid rgba(0, 0, 0, .08);
  }

  .nav.is-open {
    display: grid;
    gap: 0;
  }

  .nav a {
    padding: 16px 0;
    border-bottom: 1px solid var(--line);
  }

  .split,
  .product-grid,
  .company-grid,
  .contact {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .hero-image {
    width: 150%;
    margin-left: -25%;
  }

  .footer {
    flex-direction: column;
  }

  .footer-links {
    justify-content: flex-start;
  }
}