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

:root {
  --bg: #f7f9fc;
  --ink: #0b1220;
  --muted: #5f6f86;
  --line: #e4eaf3;
  --card: #ffffff;
  --soft: #eef5ff;
  --blue: #2563eb;
  --blue-2: #0ea5e9;
  --indigo: #4f46e5;
  --green: #10b981;
  --orange: #f59e0b;
  --shadow: 0 24px 70px rgba(15, 23, 42, .1);
  --radius: 24px;
}

html {
  scroll-behavior: smooth;
}

body {
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 6%, rgba(37, 99, 235, .14), transparent 26%),
    radial-gradient(circle at 92% 0%, rgba(14, 165, 233, .12), transparent 28%),
    var(--bg);
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  line-height: 1.7;
}

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

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

.container {
  width: min(1180px, 92%);
  margin: 0 auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid rgba(228, 234, 243, .9);
  background: rgba(255, 255, 255, .86);
  backdrop-filter: blur(20px);
}

.nav {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 22px;
  font-weight: 900;
  letter-spacing: -.03em;
}

.brand-mark {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  color: #fff;
  background: linear-gradient(135deg, var(--blue), var(--indigo));
  box-shadow: 0 14px 30px rgba(37, 99, 235, .25);
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 6px;
  color: #34445b;
  font-size: 14px;
  font-weight: 800;
}

.nav-links a,
.lang {
  padding: 9px 12px;
  border-radius: 999px;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--blue);
  background: var(--soft);
}

.lang {
  border: 1px solid var(--line);
  color: #334155;
  background: #fff;
  font-size: 13px;
  font-weight: 900;
}

.section {
  padding: 82px 0;
}

.hero {
  padding: 84px 0 64px;
}

.hero-grid,
.split {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 520px);
  align-items: center;
  gap: 54px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  padding: 8px 14px;
  border: 1px solid #cfe0ff;
  border-radius: 999px;
  color: #1d4ed8;
  background: rgba(255, 255, 255, .78);
  font-size: 13px;
  font-weight: 900;
}

h1,
h2,
h3 {
  line-height: 1.14;
  letter-spacing: -.045em;
}

h1 {
  max-width: 820px;
  font-size: clamp(42px, 7vw, 76px);
}

h2 {
  font-size: clamp(30px, 4.4vw, 50px);
}

h3 {
  font-size: 22px;
}

.lead {
  max-width: 780px;
  margin-top: 22px;
  color: var(--muted);
  font-size: 18px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 13px 23px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-weight: 900;
  transition: transform .2s ease, box-shadow .2s ease;
}

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

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--blue), var(--blue-2));
  box-shadow: 0 18px 38px rgba(37, 99, 235, .24);
}

.btn-light {
  color: var(--blue);
  border-color: #cfe0ff;
  background: #fff;
}

.trust {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  margin-top: 34px;
}

.trust-card,
.card,
.feature,
.platform,
.protocol,
.step,
.faq,
.download-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, .86);
  box-shadow: 0 14px 38px rgba(15, 23, 42, .05);
}

.trust-card {
  padding: 16px;
}

.trust-card strong {
  display: block;
  font-size: 20px;
}

.trust-card span,
.muted {
  color: var(--muted);
}

.hero-media {
  position: relative;
}

.hero-media img {
  width: 100%;
  border-radius: 32px;
  box-shadow: var(--shadow);
}

.status-card {
  position: absolute;
  left: -18px;
  bottom: 28px;
  width: min(290px, 72%);
  padding: 18px;
  border: 1px solid rgba(255, 255, 255, .74);
  border-radius: 22px;
  background: rgba(255, 255, 255, .82);
  box-shadow: 0 18px 42px rgba(15, 23, 42, .12);
  backdrop-filter: blur(18px);
}

.status-line {
  height: 8px;
  margin-top: 14px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--green), var(--blue-2), var(--blue));
}

.section-head {
  max-width: 840px;
  margin: 0 auto 42px;
  text-align: center;
}

.section-head p {
  margin-top: 14px;
  color: var(--muted);
}

.grid {
  display: grid;
  gap: 20px;
}

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

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

.grid-4 {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.card,
.feature,
.platform,
.protocol,
.step,
.faq,
.download-card {
  padding: 24px;
}

.platform-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.tag {
  display: inline-flex;
  width: fit-content;
  padding: 6px 10px;
  border-radius: 999px;
  color: #1d4ed8;
  background: #eaf2ff;
  font-size: 12px;
  font-weight: 900;
}

.ok {
  color: #047857;
  background: #dcfce7;
}

.feature {
  min-height: 230px;
}

.icon {
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  margin-bottom: 18px;
  border-radius: 16px;
  color: #fff;
  background: linear-gradient(135deg, var(--blue), var(--indigo));
  font-weight: 900;
}

.feature p,
.platform p,
.protocol p,
.step p,
.faq p,
.download-card p {
  margin-top: 12px;
}

.code-card {
  overflow: hidden;
  border-radius: var(--radius);
  background: #101827;
  box-shadow: var(--shadow);
}

.code-head {
  display: flex;
  gap: 8px;
  padding: 16px;
  border-bottom: 1px solid rgba(255, 255, 255, .08);
}

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: #fb7185;
}

.dot:nth-child(2) {
  background: #fbbf24;
}

.dot:nth-child(3) {
  background: #34d399;
}

pre {
  overflow-x: auto;
  padding: 22px;
  color: #dbeafe;
  font-size: 14px;
  line-height: 1.75;
}

.check-list {
  display: grid;
  gap: 12px;
  margin-top: 22px;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 28px;
  color: #334155;
}

.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--green);
  font-weight: 900;
}

.download-card img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  margin-bottom: 18px;
  border-radius: 20px;
}

.step-num {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  margin-bottom: 18px;
  border-radius: 14px;
  color: #fff;
  background: linear-gradient(135deg, var(--blue), var(--blue-2));
  font-weight: 900;
}

.notice {
  padding: 16px 18px;
  border: 1px solid #fde68a;
  border-radius: 18px;
  color: #854d0e;
  background: #fffbeb;
}

.cta {
  overflow: hidden;
  color: #fff;
  border-radius: 38px;
  background:
    radial-gradient(circle at 12% 20%, rgba(14, 165, 233, .34), transparent 34%),
    linear-gradient(135deg, #0b1220, #1d4ed8 58%, #0ea5e9);
  box-shadow: var(--shadow);
}

.cta-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 24px;
  padding: 42px;
}

.cta p {
  margin-top: 12px;
  color: #dbeafe;
}

.page-hero {
  padding: 72px 0 42px;
}

footer {
  padding: 56px 0 34px;
  color: #64748b;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(4, 1fr);
  gap: 24px;
}

.footer-col h3 {
  margin-bottom: 14px;
  color: var(--ink);
  font-size: 16px;
}

.footer-col a,
.footer-col span {
  display: block;
  margin-bottom: 8px;
  color: #64748b;
  font-size: 14px;
}

.copyright {
  margin-top: 32px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  font-size: 13px;
}

@media (max-width: 980px) {
  .hero-grid,
  .split,
  .cta-inner {
    grid-template-columns: 1fr;
  }

  .grid-3,
  .grid-4,
  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .nav {
    align-items: flex-start;
    flex-direction: column;
    padding: 16px 0;
  }
}

@media (max-width: 640px) {
  .grid-2,
  .grid-3,
  .grid-4,
  .trust,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 56px 0;
  }

  .status-card {
    position: static;
    width: 100%;
    margin-top: 16px;
  }
}