:root {
  --ink: #111827;
  --muted: #667085;
  --line: #e3e5e8;
  --soft: #f6f7f8;
  --yellow: #f5c744;
  --yellow-strong: #eab318;
  --dark: #131c27;
  --max: 1200px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: #fff;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", sans-serif;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  width: 100%;
  min-height: 74px;
  align-items: center;
  padding: 0 max(24px, calc((100vw - var(--max)) / 2));
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid rgba(17, 24, 39, 0.09);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  justify-self: start;
  font-size: 20px;
  font-weight: 900;
  letter-spacing: -0.04em;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  color: #171717;
  font-size: 13px;
  font-weight: 900;
  background: var(--yellow);
  border-radius: 9px;
}

nav {
  display: flex;
  gap: 38px;
  font-size: 14px;
  font-weight: 750;
}

nav a:hover,
.footer-links a:hover {
  color: #9a6b00;
}

.header-action {
  min-height: 44px;
  padding: 12px 20px;
  justify-self: end;
  font-size: 14px;
  font-weight: 800;
  background: var(--yellow);
  border-radius: 8px;
  box-shadow: 0 8px 22px rgba(197, 143, 0, 0.15);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(460px, 0.9fr);
  width: min(var(--max), calc(100% - 48px));
  min-height: 650px;
  align-items: center;
  gap: 80px;
  margin: 0 auto;
  padding: 72px 0;
}

.hero h1 {
  max-width: 680px;
  margin: 0;
  font-size: clamp(52px, 5vw, 76px);
  line-height: 1.07;
  letter-spacing: -0.065em;
}

.hero-copy > p {
  max-width: 650px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.9;
}

.hero-actions {
  display: flex;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  min-width: 148px;
  min-height: 50px;
  align-items: center;
  justify-content: center;
  padding: 0 22px;
  font-size: 14px;
  font-weight: 850;
  border-radius: 8px;
}

.primary {
  background: var(--yellow);
  border: 1px solid var(--yellow);
}

.secondary {
  background: #fff;
  border: 1px solid #1e2530;
}

.hero-visual {
  position: relative;
  min-height: 470px;
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(245, 199, 68, 0.16), transparent 48%),
    var(--soft);
  border: 1px solid var(--line);
  border-radius: 26px;
}

.visual-label {
  position: absolute;
  top: 38px;
  left: 40px;
  font-size: 15px;
  font-weight: 850;
}

.visual-phone {
  position: absolute;
  top: 90px;
  left: 50%;
  display: grid;
  width: 235px;
  height: 295px;
  align-content: start;
  gap: 20px;
  padding: 32px 26px;
  background: #fff;
  border: 9px solid #17191d;
  border-radius: 26px;
  box-shadow: 0 28px 60px rgba(18, 24, 33, 0.18);
  transform: translateX(-50%);
}

.visual-phone > span {
  position: absolute;
  top: 0;
  left: 50%;
  width: 76px;
  height: 16px;
  background: #17191d;
  border-radius: 0 0 10px 10px;
  transform: translateX(-50%);
}

.visual-phone strong {
  margin-top: 12px;
  font-size: 20px;
}

.visual-phone i {
  display: block;
  height: 42px;
  background: #f2f3f5;
  border-left: 6px solid var(--yellow);
  border-radius: 6px;
}

.visual-flow {
  position: absolute;
  right: 28px;
  bottom: 26px;
  left: 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 17px 20px;
  font-size: 12px;
  font-weight: 800;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
}

.visual-flow b {
  color: var(--yellow-strong);
}

.section {
  padding: 108px max(24px, calc((100vw - var(--max)) / 2));
  scroll-margin-top: 74px;
}

.section-heading > span,
.security-copy > span {
  color: #9a6b00;
  font-size: 13px;
  font-weight: 850;
  letter-spacing: 0.12em;
}

.section-heading h2,
.security h2 {
  max-width: 760px;
  margin: 16px 0 0;
  font-size: clamp(34px, 4vw, 54px);
  line-height: 1.16;
  letter-spacing: -0.045em;
}

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

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  margin-top: 54px;
}

.about-grid > p {
  margin: 0;
  color: #424b57;
  font-size: 17px;
  line-height: 2;
}

dl {
  margin: 0;
  border-top: 1px solid #d4d8dd;
}

dl div {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 24px;
  padding: 19px 0;
  border-bottom: 1px solid #d4d8dd;
}

dt {
  color: var(--muted);
  font-size: 13px;
}

dd {
  margin: 0;
  font-size: 14px;
  font-weight: 750;
}

.product-heading {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: end;
  column-gap: 80px;
}

.product-heading > span {
  grid-column: 1 / -1;
}

.product-heading p {
  margin: 16px 0 6px;
  color: var(--muted);
  line-height: 1.8;
}

.product-image {
  display: block;
  width: 100%;
  height: auto;
  margin-top: 58px;
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 28px 70px rgba(18, 24, 33, 0.1);
}

.product-features {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin-top: 64px;
  border-top: 1px solid var(--line);
}

.product-features article {
  padding: 28px 28px 10px 0;
  border-right: 1px solid var(--line);
}

.product-features article + article {
  padding-left: 28px;
}

.product-features article:last-child {
  border-right: 0;
}

.product-features span {
  color: #b07d00;
  font-size: 14px;
  font-weight: 900;
}

.product-features h3 {
  margin: 18px 0 0;
  font-size: 19px;
}

.product-features p {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.8;
}

.security {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 100px;
  color: #edf1f6;
  background: var(--dark);
}

.security h2 {
  color: #fff;
}

.security-copy p {
  max-width: 570px;
  margin: 24px 0 0;
  color: #aeb8c5;
  line-height: 1.9;
}

.security ul {
  padding: 0;
  margin: 8px 0 0;
  list-style: none;
  border-top: 1px solid #34404d;
}

.security li {
  padding: 19px 0;
  border-bottom: 1px solid #34404d;
}

.security li::before {
  margin-right: 12px;
  color: var(--yellow);
  content: "✓";
  font-weight: 900;
}

footer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 34px 60px;
  padding: 52px max(24px, calc((100vw - var(--max)) / 2));
  background: #fff;
  border-top: 1px solid var(--line);
}

footer > div:first-child strong,
footer > div:first-child span {
  display: block;
}

footer > div:first-child strong {
  font-size: 18px;
}

footer > div:first-child span {
  margin-top: 7px;
  color: var(--muted);
  font-size: 12px;
}

.footer-links {
  display: flex;
  gap: 30px;
  font-size: 13px;
}

footer > p {
  display: flex;
  grid-column: 1 / -1;
  flex-wrap: wrap;
  gap: 12px 24px;
  padding-top: 22px;
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  border-top: 1px solid var(--line);
}

footer > p a {
  color: #4a5563;
}

@media (max-width: 900px) {
  .site-header {
    grid-template-columns: 1fr auto;
  }

  .site-header nav {
    display: none;
  }

  .hero {
    grid-template-columns: 1fr;
    gap: 50px;
    padding-top: 58px;
  }

  .hero-visual {
    min-height: 430px;
  }

  .about-grid,
  .security {
    grid-template-columns: 1fr;
    gap: 50px;
  }

  .product-features {
    grid-template-columns: repeat(2, 1fr);
  }

  .product-features article:nth-child(2) {
    border-right: 0;
  }
}

@media (max-width: 600px) {
  .site-header {
    min-height: 66px;
    padding: 0 16px;
  }

  .brand {
    font-size: 18px;
  }

  .brand-mark {
    width: 34px;
    height: 34px;
  }

  .header-action {
    min-height: 40px;
    padding: 10px 14px;
    font-size: 12px;
  }

  .hero {
    width: calc(100% - 32px);
    min-height: auto;
    padding: 52px 0 66px;
  }

  .hero h1 {
    font-size: 46px;
  }

  .hero-copy > p {
    font-size: 15px;
  }

  .hero-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .button {
    min-width: 0;
    padding: 0 12px;
  }

  .hero-visual {
    min-height: 390px;
    border-radius: 18px;
  }

  .visual-label {
    top: 26px;
    left: 24px;
  }

  .visual-phone {
    top: 72px;
    width: 210px;
    height: 260px;
  }

  .visual-flow {
    right: 16px;
    bottom: 16px;
    left: 16px;
  }

  .section {
    padding: 76px 16px;
  }

  .section-heading h2,
  .security h2 {
    font-size: 36px;
  }

  .about-grid {
    margin-top: 38px;
  }

  dl div {
    grid-template-columns: 82px 1fr;
  }

  .product-heading {
    display: block;
  }

  .product-image {
    margin-top: 38px;
    border-radius: 10px;
  }

  .product-features {
    grid-template-columns: 1fr;
    margin-top: 42px;
  }

  .product-features article,
  .product-features article + article {
    padding: 24px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  footer {
    display: block;
    padding: 42px 16px;
  }

  .footer-links {
    margin-top: 28px;
  }

  footer > p {
    display: grid;
    margin-top: 28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}