:root {
  --ink: #15181b;
  --muted: #5a646b;
  --paper: #f5f7f4;
  --panel: #ffffff;
  --line: #d9dfd9;
  --green: #2f776a;
  --green-dark: #174f48;
  --copper: #b56d2b;
  --amber: #f0b653;
  --shadow: 0 18px 50px rgba(21, 24, 27, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: "Aptos", "Microsoft YaHei UI", "Noto Sans SC", Arial, sans-serif;
  background: linear-gradient(180deg, #eef3ef 0%, #f8f6f0 48%, #eef2f1 100%);
}

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

.topbar,
main,
footer {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  padding: 18px 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 180px;
}

.brand img {
  width: 42px;
  height: 42px;
}

.brand strong,
.brand small {
  display: block;
  line-height: 1.1;
}

.brand strong {
  font-size: 20px;
  font-weight: 900;
}

.brand small {
  color: var(--muted);
  font-size: 12px;
}

nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

nav a {
  padding: 9px 12px;
  border-radius: 999px;
  color: #2d373b;
  font-size: 14px;
  font-weight: 700;
}

nav a:hover {
  background: rgba(47, 119, 106, 0.12);
  color: var(--green-dark);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 0.82fr);
  gap: 44px;
  align-items: center;
  padding: 52px 0 46px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--copper);
  font-size: 13px;
  font-weight: 900;
}

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

h1 {
  margin-bottom: 20px;
  font-size: 64px;
  line-height: 1;
}

h2 {
  margin-bottom: 14px;
  font-size: 36px;
  line-height: 1.15;
}

h3 {
  margin-bottom: 10px;
  font-size: 20px;
}

.lead,
.section-heading p,
.grid p,
.download-panel p,
.steps span {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.75;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 28px 0 22px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 20px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-weight: 900;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.button:hover {
  transform: translateY(-1px);
  box-shadow: 0 12px 30px rgba(21, 24, 27, 0.14);
}

.button.primary {
  color: #fff;
  border-color: var(--green-dark);
  background: linear-gradient(135deg, var(--green-dark), var(--green));
}

.button.disabled {
  cursor: not-allowed;
  opacity: 0.68;
}

.button.disabled:hover {
  box-shadow: none;
  transform: none;
}

.button.secondary {
  background: rgba(255, 255, 255, 0.7);
}

.facts {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.facts li {
  padding: 8px 12px;
  border: 1px solid rgba(47, 119, 106, 0.22);
  border-radius: 999px;
  color: var(--green-dark);
  background: rgba(255, 255, 255, 0.62);
  font-size: 13px;
  font-weight: 800;
}

.hero-visual {
  padding: 18px;
  border: 1px solid rgba(255, 255, 255, 0.8);
  border-radius: 8px;
  background: #202629;
  box-shadow: var(--shadow);
}

.surface {
  position: relative;
  min-height: 360px;
  overflow: hidden;
  border-radius: 8px;
  background:
    linear-gradient(160deg, rgba(255, 255, 255, 0.16), transparent 34%),
    repeating-linear-gradient(170deg, rgba(255, 255, 255, 0.09) 0 2px, transparent 2px 24px),
    linear-gradient(135deg, #2f776a, #11181b);
}

.surface::before {
  content: "";
  position: absolute;
  left: -12%;
  right: -12%;
  bottom: 42px;
  height: 130px;
  background: linear-gradient(180deg, rgba(240, 182, 83, 0.35), rgba(240, 182, 83, 0.05));
  transform: rotate(-7deg);
}

.engraved-text {
  position: absolute;
  left: 46px;
  top: 118px;
  color: rgba(255, 255, 255, 0.9);
  font-size: 72px;
  font-weight: 900;
  text-shadow: 0 8px 0 rgba(0, 0, 0, 0.28), 0 -2px 0 rgba(255, 255, 255, 0.18);
  transform: rotate(-7deg) skewX(-5deg);
}

.groove-line {
  position: absolute;
  left: 42px;
  right: 48px;
  bottom: 104px;
  height: 8px;
  border-radius: 999px;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.78), transparent);
  transform: rotate(-7deg);
}

.axis {
  position: absolute;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border: 1px solid rgba(255, 255, 255, 0.26);
  border-radius: 50%;
  color: #fff;
  background: rgba(21, 24, 27, 0.45);
  font-weight: 900;
}

.h-axis {
  right: 28px;
  bottom: 76px;
}

.v-axis {
  right: 82px;
  bottom: 150px;
}

.visual-caption {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-top: 14px;
  color: rgba(255, 255, 255, 0.76);
  font-size: 13px;
  font-weight: 800;
}

.visual-caption img {
  width: 28px;
  height: 28px;
}

.section {
  padding: 58px 0;
}

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

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

.grid article {
  min-height: 210px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
  box-shadow: 0 12px 36px rgba(21, 24, 27, 0.06);
}

.download-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 28px;
  align-items: center;
  padding: 30px;
  border: 1px solid rgba(23, 79, 72, 0.24);
  border-radius: 8px;
  color: #fff;
  background: linear-gradient(135deg, #15181b, #174f48);
  box-shadow: var(--shadow);
}

.download-panel p {
  color: rgba(255, 255, 255, 0.72);
}

.download-panel .eyebrow {
  color: var(--amber);
}

.hash {
  margin: 16px 0 0;
  overflow-wrap: anywhere;
  font-size: 13px !important;
}

.hash span {
  color: rgba(255, 255, 255, 0.88);
  font-family: Consolas, "Courier New", monospace;
}

.notice {
  margin: 14px 0 0;
  padding: 12px 14px;
  border: 1px solid rgba(240, 182, 83, 0.42);
  border-radius: 8px;
  background: rgba(240, 182, 83, 0.1);
  font-size: 14px !important;
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: steps;
}

.steps li {
  counter-increment: steps;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
}

.steps li::before {
  content: "0" counter(steps);
  display: block;
  margin-bottom: 28px;
  color: var(--copper);
  font-size: 28px;
  font-weight: 900;
}

.steps strong,
.steps span {
  display: block;
}

.steps strong {
  margin-bottom: 8px;
  font-size: 20px;
}

footer {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 34px 0 44px;
  color: var(--muted);
  font-size: 14px;
  text-align: center;
}

footer strong,
footer span {
  display: block;
}

footer strong {
  color: var(--ink);
}

.footer-legal {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.footer-legal p {
  margin: 0;
}

.beian-links {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px 18px;
}

.police-beian {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.police-beian img {
  width: 20px;
  height: 20px;
  object-fit: contain;
  flex: 0 0 auto;
}

@media (max-width: 860px) {
  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }

  nav {
    flex-wrap: wrap;
  }

  .hero,
  .download-panel,
  .grid,
  .steps {
    grid-template-columns: 1fr;
  }

  h1 {
    font-size: 48px;
  }

  h2 {
    font-size: 30px;
  }

  .hero {
    padding-top: 28px;
  }

  .download-panel .button {
    justify-self: start;
  }
}

@media (max-width: 520px) {
  .topbar,
  main,
  footer {
    width: min(100% - 24px, 1120px);
  }

  h1 {
    font-size: 40px;
  }

  .actions {
    align-items: stretch;
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .surface {
    min-height: 280px;
  }

  .engraved-text {
    left: 28px;
    top: 98px;
    font-size: 52px;
  }

  footer {
    align-items: flex-start;
    text-align: left;
  }

  .footer-legal {
    align-items: flex-start;
  }

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