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

:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --surface-strong: #f0f7f4;
  --ink: #171717;
  --muted: #64615a;
  --line: rgba(23, 23, 23, 0.12);
  --green: #1f8a70;
  --green-dark: #146a56;
  --yellow: #ffc857;
  --red: #f05d5e;
  --blue: #3d84e6;
  --shadow: 0 24px 60px rgba(31, 46, 38, 0.14);
  --radius: 8px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111312;
    --surface: #1a1d1b;
    --surface-strong: #17241f;
    --ink: #f3f1eb;
    --muted: #b4ada2;
    --line: rgba(243, 241, 235, 0.14);
    --shadow: 0 24px 60px rgba(0, 0, 0, 0.38);
  }
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  background:
    linear-gradient(90deg, rgba(31, 138, 112, 0.07) 1px, transparent 1px),
    linear-gradient(180deg, rgba(31, 138, 112, 0.07) 1px, transparent 1px),
    var(--bg);
  background-size: 44px 44px;
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

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

img {
  display: block;
  max-width: 100%;
}

.container {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 90%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  gap: 24px;
}

.logo,
.nav-links,
.footer-links {
  display: flex;
  align-items: center;
}

.logo {
  gap: 10px;
  font-size: 1rem;
  font-weight: 800;
}

.logo img {
  border-radius: 10px;
}

.nav-links {
  gap: 22px;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 650;
}

.nav-links a:hover,
.footer a:hover {
  color: var(--green);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  background: var(--green);
  color: #fff;
  font-weight: 800;
  transition:
    background-color 0.16s ease,
    transform 0.16s ease;
  white-space: nowrap;
}

.btn:hover {
  background: var(--green-dark);
  color: #fff;
}

.btn:active,
.store-btn:active {
  transform: translateY(1px);
}

.btn-sm {
  min-height: 40px;
  padding: 0 16px;
  border-radius: 999px;
}

.hero {
  padding: 58px 0 44px;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(320px, 0.98fr);
  align-items: center;
  gap: 56px;
}

.eyebrow {
  color: var(--green);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  margin-bottom: 14px;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  line-height: 1.08;
}

.hero h1 {
  max-width: 660px;
  font-size: clamp(2.5rem, 5.8vw, 4.7rem);
  font-weight: 950;
  letter-spacing: 0;
}

.hero-sub {
  max-width: 560px;
  margin-top: 20px;
  color: var(--muted);
  font-size: 1.16rem;
}

.download-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}

.store-btn {
  display: inline-flex;
  align-items: center;
  min-height: 52px;
  transition:
    opacity 0.16s ease,
    transform 0.16s ease;
}

.store-btn:hover {
  opacity: 0.82;
}

.store-btn img {
  width: auto;
  height: 50px;
}

.download-note {
  max-width: 460px;
  margin-top: 14px;
  color: var(--muted);
  font-size: 0.94rem;
}

.hero-visual {
  display: flex;
  justify-content: center;
}

.cube-card {
  position: relative;
  width: min(100%, 410px);
  min-height: 520px;
  display: grid;
  place-items: center;
}

.cube-card::before {
  position: absolute;
  inset: 40px 0 10px 44px;
  z-index: -1;
  border: 1px solid var(--line);
  background:
    linear-gradient(135deg, rgba(255, 200, 87, 0.32), transparent 44%),
    linear-gradient(315deg, rgba(61, 132, 230, 0.18), transparent 45%),
    var(--surface-strong);
  box-shadow: var(--shadow);
  content: "";
  transform: rotate(2deg);
}

.floating-cube {
  position: absolute;
  top: 0;
  right: 12px;
  z-index: 2;
  width: 124px;
  filter: drop-shadow(0 18px 24px rgba(0, 0, 0, 0.18));
}

.mockup-frame {
  width: min(100%, 286px);
  padding: 12px;
  border: 1px solid rgba(255, 255, 255, 0.38);
  border-radius: 34px;
  background: #171717;
  box-shadow: 0 26px 46px rgba(0, 0, 0, 0.22);
}

.mockup-image {
  width: 100%;
  border-radius: 25px;
}

.solver-strip {
  padding: 22px 0 76px;
}

.strip-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--line);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.strip-grid > div {
  padding: 26px;
}

.strip-grid > div + div {
  border-left: 1px solid var(--line);
}

.strip-grid span {
  display: block;
  color: var(--red);
  font-size: 0.78rem;
  font-weight: 950;
  margin-bottom: 8px;
}

.strip-grid strong {
  display: block;
  font-size: 1.04rem;
  margin-bottom: 6px;
}

.strip-grid p {
  color: var(--muted);
  font-size: 0.94rem;
}

.features,
.faq {
  padding: 78px 0;
}

.features {
  background: color-mix(in srgb, var(--surface-strong) 82%, transparent);
  border-block: 1px solid var(--line);
}

.section-heading {
  max-width: 620px;
  margin-bottom: 34px;
}

.section-heading h2,
.details h2 {
  font-size: clamp(2rem, 4vw, 3.35rem);
  font-weight: 950;
  letter-spacing: 0;
}

.features-grid,
.faq-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.feature-card,
.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.feature-card {
  padding: 28px;
}

.feature-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 58px;
  min-height: 28px;
  margin-bottom: 26px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--green-dark);
  font-size: 0.76rem;
  font-weight: 900;
  text-transform: uppercase;
}

.feature-card:nth-child(2) .feature-mark {
  color: var(--blue);
}

.feature-card:nth-child(3) .feature-mark {
  color: #a36300;
}

.feature-card h3,
.faq-item h3 {
  font-size: 1.15rem;
  font-weight: 900;
  margin-bottom: 12px;
}

.feature-card p,
.faq-item p,
.article p,
.prose p,
.prose li {
  color: var(--muted);
}

.details {
  padding: 84px 0;
}

.details-grid {
  display: grid;
  grid-template-columns: 0.82fr 1fr;
  gap: 54px;
  align-items: start;
}

.article {
  border-left: 4px solid var(--yellow);
  padding-left: 28px;
}

.article p + p {
  margin-top: 20px;
}

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

.faq-item {
  padding: 24px;
}

.footer {
  padding: 28px 0;
  border-top: 1px solid var(--line);
  background: var(--surface);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  color: var(--muted);
  font-size: 0.9rem;
}

.footer-links {
  gap: 18px;
}

.prose {
  max-width: 760px;
  margin: 0 auto;
  padding: 58px 24px 84px;
}

.prose h1 {
  font-size: clamp(2.1rem, 5vw, 3.2rem);
  font-weight: 950;
  letter-spacing: 0;
  margin-bottom: 10px;
}

.prose .meta {
  margin-bottom: 38px;
  color: var(--muted);
  font-size: 0.92rem;
}

.prose h2 {
  font-size: 1.2rem;
  font-weight: 900;
  margin: 34px 0 12px;
}

.prose p,
.prose li {
  line-height: 1.75;
  margin-bottom: 12px;
}

.prose ul {
  padding-left: 20px;
}

.prose a {
  color: var(--green);
  font-weight: 750;
}

.prose a:hover {
  text-decoration: underline;
}

@media (max-width: 860px) {
  .hero {
    padding-top: 54px;
  }

  .hero-inner,
  .details-grid {
    grid-template-columns: 1fr;
  }

  .hero h1,
  .hero-sub,
  .section-heading,
  .details h2 {
    max-width: none;
  }

  .cube-card {
    min-height: 480px;
  }

  .strip-grid,
  .features-grid,
  .faq-grid {
    grid-template-columns: 1fr;
  }

  .strip-grid > div + div {
    border-top: 1px solid var(--line);
    border-left: 0;
  }
}

@media (max-width: 640px) {
  .container {
    width: min(100% - 28px, 1120px);
  }

  .header-inner {
    min-height: 58px;
  }

  .nav-links a:not(.btn) {
    display: none;
  }

  .hero {
    padding: 42px 0 34px;
  }

  .hero h1 {
    font-size: 2.7rem;
  }

  .download-btns {
    gap: 10px;
  }

  .store-btn img {
    height: 46px;
  }

  .cube-card {
    min-height: 410px;
  }

  .cube-card::before {
    inset: 34px 0 8px 18px;
  }

  .floating-cube {
    width: 96px;
  }

  .mockup-frame {
    width: 240px;
  }

  .solver-strip,
  .features,
  .details,
  .faq {
    padding-block: 54px;
  }

  .feature-card,
  .faq-item,
  .strip-grid > div {
    padding: 22px;
  }

  .article {
    padding-left: 20px;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}