:root {
  color-scheme: light;
  --bg: #f4f7fb;
  --surface: #ffffff;
  --surface-2: #edf3fa;
  --ink: #162033;
  --muted: #5c6b80;
  --line: #d8e1ec;
  --brand: #3177b8;
  --brand-2: #74a9dc;
  --brand-dark: #123a5f;
  --green: #1f8a5f;
  --amber: #b66b14;
  --shadow: 0 18px 45px rgba(18, 58, 95, 0.12);
  --radius: 8px;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.65;
}

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

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

p {
  margin: 0;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(244, 247, 251, 0.92);
  border-bottom: 1px solid rgba(216, 225, 236, 0.86);
  backdrop-filter: blur(16px);
}

.nav {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  letter-spacing: 0;
}

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

.brand small {
  display: block;
  color: var(--muted);
  font-size: 12px;
  font-weight: 600;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
  color: #2c3c51;
  font-size: 15px;
  font-weight: 650;
}

.nav-links a {
  padding: 8px 0;
  border-bottom: 2px solid transparent;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--brand);
  border-bottom-color: var(--brand);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  background: var(--brand);
  color: #fff;
  font-weight: 750;
  font-size: 15px;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
  background: #286ca9;
  box-shadow: 0 10px 22px rgba(49, 119, 184, 0.22);
}

.btn.secondary {
  background: #fff;
  color: var(--brand-dark);
  border-color: var(--line);
}

.btn.secondary:hover {
  background: #f7fbff;
  box-shadow: 0 10px 22px rgba(18, 58, 95, 0.08);
}

.btn.ghost {
  background: transparent;
  color: var(--brand-dark);
  border-color: var(--line);
}

.hero {
  padding: 82px 0 72px;
  background:
    radial-gradient(circle at 80% 18%, rgba(116, 169, 220, 0.22), transparent 32%),
    linear-gradient(180deg, #f8fbff 0%, #eef4fb 100%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 0.98fr 1.02fr;
  gap: 54px;
  align-items: center;
}

.hero h1 {
  margin: 0 0 20px;
  color: #102033;
  font-size: clamp(42px, 5vw, 68px);
  line-height: 1.05;
  letter-spacing: 0;
}

.lead {
  color: #405269;
  font-size: 19px;
  line-height: 1.85;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 30px 0;
}

.trust-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 26px;
}

.trust-item {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.72);
}

.trust-item strong {
  display: block;
  color: var(--brand-dark);
  font-size: 20px;
}

.trust-item span {
  color: var(--muted);
  font-size: 13px;
}

.hero-media {
  position: relative;
}

.hero-panel {
  overflow: hidden;
  border: 1px solid #cfddeb;
  border-radius: var(--radius);
  background: #fff;
  box-shadow: var(--shadow);
}

.hero-panel img {
  width: 100%;
}

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

.status-strip div {
  padding: 14px 16px;
  background: #f8fbff;
}

.status-strip strong {
  display: block;
  color: var(--brand-dark);
  font-size: 14px;
}

.status-strip span {
  color: var(--muted);
  font-size: 12px;
}

.section {
  padding: 78px 0;
}

.section.tight {
  padding: 52px 0;
}

.section.white {
  background: #fff;
}

.section.dark {
  background: #102033;
  color: #f6fbff;
}

.section.dark .section-title p,
.section.dark .muted,
.section.dark .card p,
.section.dark .step p {
  color: #c8d7e7;
}

.section-title {
  max-width: 760px;
  margin-bottom: 34px;
}

.section-title.center {
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

.section-title h2,
.page-title h1 {
  margin: 0 0 12px;
  font-size: clamp(30px, 3.5vw, 46px);
  line-height: 1.15;
  letter-spacing: 0;
}

.section-title p,
.page-title p {
  color: var(--muted);
  font-size: 17px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
}

.card {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 0 12px 30px rgba(18, 58, 95, 0.06);
}

.section.dark .card {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.13);
  box-shadow: none;
}

.icon {
  width: 42px;
  height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  border-radius: var(--radius);
  background: #e8f2fb;
  color: var(--brand-dark);
  font-size: 22px;
}

.card h3,
.step h3,
.download-box h3 {
  margin: 0 0 10px;
  font-size: 21px;
  line-height: 1.3;
}

.card p,
.step p,
.download-box p,
.muted {
  color: var(--muted);
}

.media-row {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  gap: 36px;
  align-items: center;
}

.media-frame {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  box-shadow: var(--shadow);
}

.list {
  display: grid;
  gap: 14px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
}

.list li {
  position: relative;
  padding-left: 30px;
  color: #34465c;
}

.list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 14px;
  height: 14px;
  border-radius: 4px;
  background: var(--brand);
  box-shadow: inset 0 0 0 3px #d9ecfb;
}

.scenario {
  display: grid;
  grid-template-columns: 0.8fr 1.2fr;
  gap: 22px;
  align-items: stretch;
}

.scenario-nav {
  display: grid;
  gap: 12px;
}

.scenario-nav button {
  width: 100%;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  color: #26384d;
  font: inherit;
  font-weight: 750;
  text-align: left;
  cursor: pointer;
}

.scenario-nav button.active,
.scenario-nav button:hover {
  border-color: var(--brand);
  background: #eef6fd;
  color: var(--brand-dark);
}

.scenario-panel {
  padding: 30px;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid var(--line);
}

.scenario-panel h3 {
  margin: 0 0 12px;
  font-size: 26px;
}

.review-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.review {
  display: flex;
  flex-direction: column;
  min-height: 220px;
  padding: 24px;
  border: 1px solid rgba(255, 255, 255, 0.13);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.06);
}

.review p {
  flex: 1;
  color: #e4eef8;
  font-size: 16px;
}

.review cite {
  margin-top: 20px;
  color: #91c4f2;
  font-style: normal;
  font-weight: 750;
}

.page-hero {
  padding: 64px 0 50px;
  background: linear-gradient(180deg, #f8fbff 0%, #edf3fa 100%);
}

.page-title {
  max-width: 860px;
}

.crumbs {
  margin-bottom: 12px;
  color: var(--brand);
  font-size: 14px;
  font-weight: 750;
}

.feature-table {
  width: 100%;
  border-collapse: collapse;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.feature-table th,
.feature-table td {
  padding: 16px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.feature-table th {
  background: #eef5fc;
  color: var(--brand-dark);
}

.feature-table tr:last-child td {
  border-bottom: 0;
}

.steps {
  display: grid;
  gap: 18px;
  counter-reset: step;
}

.step {
  position: relative;
  padding: 24px 24px 24px 76px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.step::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 24px;
  top: 26px;
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--brand-dark);
  color: #fff;
  font-weight: 800;
}

.download-layout {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 24px;
  align-items: start;
}

.download-box {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  box-shadow: 0 12px 30px rgba(18, 58, 95, 0.06);
}

.download-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.meta-list {
  display: grid;
  gap: 10px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.meta-list li {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
}

.meta-list strong {
  color: var(--ink);
}

.faq-list {
  display: grid;
  gap: 14px;
}

.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.faq-item summary {
  padding: 18px 20px;
  color: var(--brand-dark);
  font-weight: 800;
  cursor: pointer;
}

.faq-item p {
  padding: 0 20px 20px;
  color: var(--muted);
}

.cta-band {
  padding: 44px;
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: center;
  border-radius: var(--radius);
  background: #122f4c;
  color: #fff;
}

.cta-band h2 {
  margin: 0 0 8px;
  font-size: 30px;
  line-height: 1.2;
}

.cta-band p {
  color: #c9d9e9;
}

.site-footer {
  padding: 38px 0;
  background: #0f1d2d;
  color: #c8d7e7;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: center;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-weight: 650;
}

.modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: none;
}

.modal[aria-hidden="false"] {
  display: block;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(10, 20, 32, 0.62);
}

.modal-dialog {
  position: relative;
  width: min(760px, calc(100% - 32px));
  margin: 8vh auto;
  border-radius: var(--radius);
  background: #fff;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.28);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
  padding: 22px 24px;
  border-bottom: 1px solid var(--line);
}

.modal-header h2 {
  margin: 0;
  font-size: 24px;
}

.modal-close {
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  color: var(--ink);
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
}

.modal-body {
  padding: 24px;
}

.qr-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 20px;
}

.qr-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  text-align: center;
}

.qr-card img {
  width: 160px;
  height: 160px;
  margin: 0 auto 12px;
}

.qr-card h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.qr-card p {
  color: var(--muted);
  font-size: 14px;
}

.modal-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

body.modal-open {
  overflow: hidden;
}

@media (max-width: 980px) {
  .nav {
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 0;
  }

  .nav-links {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .header-actions {
    width: 100%;
  }

  .hero-grid,
  .media-row,
  .scenario,
  .download-layout {
    grid-template-columns: 1fr;
  }

  .grid-3,
  .review-grid {
    grid-template-columns: 1fr 1fr;
  }

  .trust-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 680px) {
  .container {
    width: min(100% - 28px, var(--max));
  }

  .hero,
  .section,
  .page-hero {
    padding: 46px 0;
  }

  .grid-2,
  .grid-3,
  .review-grid,
  .qr-grid,
  .status-strip {
    grid-template-columns: 1fr;
  }

  .nav-links {
    gap: 16px;
    font-size: 14px;
  }

  .hero-actions,
  .download-actions,
  .modal-links {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .cta-band,
  .footer-grid {
    grid-template-columns: 1fr;
    display: grid;
  }

  .cta-band {
    padding: 26px;
  }

  .meta-list li {
    flex-direction: column;
    gap: 4px;
  }
}