:root {
  color-scheme: light;
  --ink: #17201c;
  --ink-strong: #07110d;
  --muted: #61706a;
  --subtle: #8d9a94;
  --paper: #f7f4ed;
  --paper-warm: #efe6d8;
  --surface: #ffffff;
  --surface-soft: #f3eee5;
  --line: rgba(23, 32, 28, 0.12);
  --green: #1f8f63;
  --green-dark: #116546;
  --blue: #286bd8;
  --coral: #da654e;
  --gold: #bd8426;
  --shadow: 0 22px 56px rgba(31, 42, 36, 0.16);
  --radius: 18px;
  font-family:
    -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
}

body,
button,
input {
  font: inherit;
}

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

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

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 16px clamp(18px, 4vw, 56px);
  color: #fff;
  transition:
    background-color 180ms ease,
    color 180ms ease,
    box-shadow 180ms ease,
    padding 180ms ease;
}

.site-header.is-scrolled {
  padding-top: 11px;
  padding-bottom: 11px;
  color: var(--ink);
  background: rgba(247, 244, 237, 0.92);
  border-bottom: 1px solid var(--line);
  box-shadow: 0 12px 36px rgba(23, 32, 28, 0.08);
  backdrop-filter: blur(16px);
}

.brand,
.nav-links,
.header-action {
  display: inline-flex;
  align-items: center;
}

.brand {
  gap: 10px;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.18);
}

.nav-links {
  gap: clamp(16px, 3vw, 32px);
  font-size: 15px;
  font-weight: 650;
}

.nav-links a {
  opacity: 0.86;
}

.nav-links a:hover {
  opacity: 1;
}

.header-action {
  min-height: 40px;
  justify-content: center;
  padding: 0 15px;
  border: 1px solid currentColor;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 700;
}

.hero {
  min-height: 94vh;
  position: relative;
  overflow: hidden;
  display: grid;
  align-items: center;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  gap: clamp(28px, 6vw, 72px);
  padding: 112px clamp(20px, 6vw, 92px) 72px;
  color: #fff;
  isolation: isolate;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -3;
  background:
    linear-gradient(90deg, rgba(7, 17, 13, 0.88), rgba(18, 52, 42, 0.68) 52%, rgba(11, 33, 27, 0.72)),
    url("assets/achieve-icon.png") center / min(760px, 92vw) no-repeat,
    #143b31;
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  z-index: -2;
  height: 28%;
  background: linear-gradient(180deg, rgba(247, 244, 237, 0), var(--paper));
}

.hero-media {
  position: absolute;
  z-index: -1;
  right: clamp(-160px, -8vw, -56px);
  top: 70px;
  width: min(600px, 72vw);
  opacity: 0.22;
  filter: saturate(1.08);
}

.hero-media img {
  border-radius: 30%;
}

.hero-copy {
  max-width: 740px;
  padding-top: 24px;
}

.eyebrow {
  margin: 0 0 12px;
  color: currentColor;
  opacity: 0.72;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin: 0;
}

h1 {
  font-size: clamp(64px, 12vw, 148px);
  line-height: 0.9;
  letter-spacing: 0;
  font-weight: 850;
}

h2 {
  font-size: clamp(32px, 5vw, 58px);
  line-height: 1.02;
  letter-spacing: 0;
  font-weight: 820;
}

h3 {
  font-size: 21px;
  line-height: 1.22;
  letter-spacing: 0;
}

.hero-subtitle {
  max-width: 650px;
  margin-top: 24px;
  color: rgba(255, 255, 255, 0.84);
  font-size: clamp(19px, 2.4vw, 27px);
  line-height: 1.42;
  font-weight: 560;
}

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

.button {
  min-height: 50px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 22px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 800;
  transition:
    transform 160ms ease,
    background-color 160ms ease,
    border-color 160ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button.primary {
  color: #fff;
  background: var(--green);
}

.button.primary:hover {
  background: var(--green-dark);
}

.button.secondary {
  color: inherit;
  border: 1px solid currentColor;
  background: rgba(255, 255, 255, 0.1);
}

.product-stage {
  display: grid;
  justify-items: center;
}

.phone-shell {
  width: min(360px, 78vw);
  min-height: 660px;
  padding: 14px;
  border: 1px solid rgba(255, 255, 255, 0.36);
  border-radius: 42px;
  background: #101713;
  box-shadow: 0 36px 80px rgba(0, 0, 0, 0.34);
}

.phone-top {
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 18px;
  color: rgba(255, 255, 255, 0.88);
  font-size: 13px;
  font-weight: 800;
}

.phone-sensors {
  width: 64px;
  height: 22px;
  border-radius: 999px;
  background: #030504;
}

.app-preview {
  min-height: 590px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 22px;
  border-radius: 30px;
  background: #f5f1e8;
  color: var(--ink);
}

.preview-topline,
.meta-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.preview-topline span,
.challenge-strip span {
  color: var(--muted);
  font-size: 14px;
  font-weight: 750;
}

.preview-topline strong {
  color: var(--green-dark);
}

.achievement-card {
  min-height: 300px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 14px;
  padding: 22px;
  border-radius: 24px;
  color: #fff;
  background:
    linear-gradient(rgba(31, 60, 48, 0.1), rgba(20, 34, 29, 0.82)),
    url("assets/achieve-icon.png") center / cover no-repeat;
}

.achievement-card h2 {
  font-size: 32px;
}

.achievement-card p {
  color: rgba(255, 255, 255, 0.82);
  line-height: 1.45;
}

.medal {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.9);
  color: var(--green-dark);
  font-weight: 900;
}

.meta-row {
  color: rgba(255, 255, 255, 0.88);
  font-size: 14px;
  font-weight: 800;
}

.mini-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.mini-grid div,
.challenge-strip {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.mini-grid div {
  min-height: 96px;
  display: grid;
  align-content: center;
  gap: 4px;
  padding: 16px;
}

.mini-grid strong {
  font-size: 34px;
  line-height: 1;
}

.mini-grid span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.challenge-strip {
  display: grid;
  gap: 6px;
  padding: 16px;
}

.challenge-strip strong {
  color: var(--green-dark);
}

.section {
  padding: clamp(70px, 10vw, 118px) clamp(20px, 6vw, 92px);
}

.section-heading {
  max-width: 840px;
  margin-bottom: 34px;
}

.section-heading .eyebrow,
.privacy-copy .eyebrow,
.download-panel .eyebrow {
  color: var(--green-dark);
  opacity: 1;
}

.section-heading p:not(.eyebrow),
.privacy-copy p,
.download-panel p {
  max-width: 760px;
  margin-top: 16px;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.62;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.feature-card {
  min-height: 270px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 24px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 0 12px 34px rgba(23, 32, 28, 0.06);
}

.feature-icon,
.scene-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  color: #fff;
  background: var(--green);
  font-size: 14px;
  font-weight: 900;
}

.feature-card p {
  color: var(--muted);
  line-height: 1.55;
}

.scenes-section {
  background: #e7efe8;
}

.section-heading.compact {
  margin-bottom: 20px;
}

.scene-list {
  display: grid;
  gap: 12px;
}

.scene-row {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 22px;
  align-items: start;
  padding: 24px 0;
  border-bottom: 1px solid rgba(23, 32, 28, 0.14);
}

.scene-row h3 {
  font-size: clamp(22px, 3vw, 34px);
}

.scene-row p {
  max-width: 820px;
  margin-top: 10px;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.55;
}

.privacy-section {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 0.85fr);
  gap: clamp(28px, 6vw, 76px);
  align-items: start;
  background: #f6f0e4;
}

.privacy-list {
  display: grid;
  gap: 12px;
}

.privacy-list div {
  display: grid;
  gap: 8px;
  padding: 18px;
  border: 1px solid rgba(23, 32, 28, 0.13);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.68);
}

.privacy-list strong {
  font-size: 18px;
}

.privacy-list span {
  color: var(--muted);
  line-height: 1.5;
}

.download-section {
  padding: 0 clamp(20px, 6vw, 92px) clamp(72px, 9vw, 110px);
}

.download-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 24px;
  align-items: center;
  padding: clamp(24px, 4vw, 42px);
  border-radius: 22px;
  background: var(--ink-strong);
  color: #fff;
  box-shadow: var(--shadow);
}

.download-panel p {
  color: rgba(255, 255, 255, 0.78);
}

.download-panel a:not(.button) {
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}

.download-actions {
  justify-content: flex-end;
  margin-top: 0;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 18px;
  padding: 28px 20px 34px;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.site-footer span {
  color: var(--ink);
  font-weight: 850;
}

@media (max-width: 980px) {
  .site-header {
    padding-inline: 18px;
  }

  .nav-links {
    display: none;
  }

  .hero {
    min-height: auto;
    grid-template-columns: 1fr;
    padding-top: 96px;
  }

  .hero-copy {
    padding-top: 0;
  }

  .product-stage {
    justify-items: start;
  }

  .feature-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .privacy-section,
  .download-panel {
    grid-template-columns: 1fr;
  }

  .download-actions {
    justify-content: flex-start;
  }
}

@media (max-width: 640px) {
  .site-header {
    gap: 10px;
  }

  .header-action {
    min-height: 36px;
    padding-inline: 12px;
    font-size: 13px;
  }

  .hero {
    padding-inline: 18px;
    padding-bottom: 54px;
  }

  .hero-actions,
  .download-actions {
    width: 100%;
  }

  .button {
    width: 100%;
  }

  .phone-shell {
    width: 100%;
    min-height: 600px;
  }

  .app-preview {
    min-height: 532px;
  }

  .achievement-card {
    min-height: 250px;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .scene-row {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .section {
    padding-inline: 18px;
  }
}