:root {
  --bg: #f6f8fb;
  --surface: #ffffff;
  --surface-soft: #edf3fa;
  --ink: #172033;
  --muted: #5f6f85;
  --line: #d9e2ee;
  --primary: #1f6feb;
  --primary-dark: #174ea6;
  --accent: #0f766e;
  --accent-soft: #d9f6ee;
  --warning: #a45b18;
  --warning-soft: #fff4df;
  --shadow: 0 18px 46px rgba(23, 32, 51, 0.10);
  --radius: 8px;
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

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

img,
svg {
  max-width: 100%;
}

a {
  color: var(--primary);
  text-decoration: none;
}

a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

.container {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.nav-wrap {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: 0;
}

.brand:hover {
  text-decoration: none;
}

.brand img {
  width: 36px;
  height: 36px;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: var(--radius);
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.nav-toggle span,
.nav-toggle span::before,
.nav-toggle span::after {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  content: "";
  border-radius: 2px;
}

.nav-toggle span::before {
  transform: translateY(-6px);
}

.nav-toggle span::after {
  transform: translateY(4px);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-links a {
  color: var(--muted);
  font-weight: 700;
  padding: 10px 13px;
  border-radius: var(--radius);
  font-size: 15px;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
  background: #eef5ff;
  text-decoration: none;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 11px 18px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  font-weight: 800;
  cursor: pointer;
  transition: transform .18s ease, box-shadow .18s ease, background .18s ease, border-color .18s ease;
  font-size: 15px;
  white-space: normal;
  text-align: center;
}

.btn:hover {
  transform: translateY(-1px);
  text-decoration: none;
}

.btn-primary {
  color: #fff;
  background: var(--primary);
  box-shadow: 0 10px 24px rgba(31, 111, 235, .24);
}

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

.btn-secondary {
  color: var(--primary);
  background: #eef5ff;
  border-color: #cfe0fb;
}

.btn-plain {
  color: var(--ink);
  background: #fff;
  border-color: var(--line);
}

.hero {
  padding: 74px 0 48px;
  background: linear-gradient(180deg, #fff 0%, #f4f8fd 100%);
  border-bottom: 1px solid var(--line);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(420px, .86fr);
  gap: 52px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 18px;
  padding: 7px 11px;
  border: 1px solid #cfe0fb;
  background: #eef5ff;
  color: var(--primary-dark);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 800;
}

h1,
h2,
h3 {
  margin: 0;
  color: var(--ink);
  line-height: 1.18;
  letter-spacing: 0;
}

h1 {
  font-size: clamp(36px, 5vw, 62px);
  max-width: 760px;
}

h2 {
  font-size: clamp(28px, 3.4vw, 42px);
}

h3 {
  font-size: 21px;
}

p {
  margin: 0;
}

.lead {
  margin-top: 20px;
  color: var(--muted);
  font-size: 18px;
  max-width: 720px;
}

.hero-actions,
.section-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.proof-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 34px;
}

.proof-item {
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.proof-value {
  display: block;
  font-size: 22px;
  font-weight: 900;
  color: var(--primary);
}

.proof-label {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-size: 13px;
}

.hero-visual {
  position: relative;
}

.hero-visual img {
  display: block;
  width: 100%;
  border-radius: 18px;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
  background: #fff;
}

.source-note {
  margin-top: 12px;
  color: var(--muted);
  font-size: 13px;
}

.section {
  padding: 72px 0;
}

.section-tight {
  padding: 48px 0;
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 28px;
  margin-bottom: 30px;
}

.section-head p {
  max-width: 620px;
  color: var(--muted);
}

.grid-3,
.grid-4,
.grid-2 {
  display: grid;
  gap: 18px;
}

.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 {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: 0 10px 28px rgba(23, 32, 51, .05);
}

.card h3 {
  margin-bottom: 10px;
}

.card p,
.card li {
  color: var(--muted);
}

.icon-box {
  width: 42px;
  height: 42px;
  border-radius: var(--radius);
  background: #eef5ff;
  border: 1px solid #cfe0fb;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  color: var(--primary);
}

.icon-box svg {
  width: 22px;
  height: 22px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.band {
  background: #172033;
  color: #fff;
}

.band h2,
.band h3 {
  color: #fff;
}

.band p,
.band li {
  color: #cbd6e5;
}

.band .card {
  background: rgba(255, 255, 255, .06);
  border-color: rgba(255, 255, 255, .16);
  box-shadow: none;
}

.media-row {
  display: grid;
  grid-template-columns: minmax(0, .92fr) minmax(0, 1fr);
  gap: 34px;
  align-items: center;
}

.media-frame {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px;
  box-shadow: var(--shadow);
}

.media-frame img {
  display: block;
  width: 100%;
  border-radius: 6px;
}

.list {
  margin: 16px 0 0;
  padding-left: 20px;
}

.list li + li {
  margin-top: 8px;
}

.steps {
  counter-reset: steps;
  display: grid;
  gap: 14px;
}

.step {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
}

.step::before {
  counter-increment: steps;
  content: counter(steps);
  width: 44px;
  height: 44px;
  border-radius: var(--radius);
  background: #eef5ff;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
}

.step p {
  color: var(--muted);
  margin-top: 6px;
}

.download-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 24px;
  align-items: stretch;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 30px;
  box-shadow: var(--shadow);
}

.release-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 18px 0 24px;
}

.pill {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  padding: 5px 10px;
  border-radius: 999px;
  background: #eef5ff;
  color: var(--primary-dark);
  border: 1px solid #cfe0fb;
  font-size: 13px;
  font-weight: 800;
}

.pill-warning {
  background: var(--warning-soft);
  border-color: #f5cf98;
  color: var(--warning);
}

.download-side {
  border-left: 1px solid var(--line);
  padding-left: 24px;
}

.qr-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.qr-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px;
  text-align: center;
}

.qr-card img {
  width: 132px;
  height: 132px;
  display: block;
  margin: 0 auto 8px;
}

.qr-card strong {
  display: block;
  color: var(--ink);
}

.qr-card span {
  display: block;
  color: var(--muted);
  font-size: 13px;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
}

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

th {
  background: #f3f7fc;
  color: var(--ink);
  font-size: 14px;
}

td {
  color: var(--muted);
}

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

.notice {
  padding: 18px;
  border-radius: var(--radius);
  border: 1px solid #f5cf98;
  background: var(--warning-soft);
  color: #66400f;
}

.notice strong {
  color: #553207;
}

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

.faq-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  border: 0;
  background: #fff;
  color: var(--ink);
  font-size: 17px;
  font-weight: 800;
  text-align: left;
  padding: 18px 20px;
  cursor: pointer;
}

.faq-question::after {
  content: "+";
  color: var(--primary);
  font-size: 22px;
  line-height: 1;
}

.faq-item.open .faq-question::after {
  content: "-";
}

.faq-answer {
  display: none;
  padding: 0 20px 18px;
  color: var(--muted);
}

.faq-item.open .faq-answer {
  display: block;
}

.site-footer {
  background: #101827;
  color: #cbd6e5;
  padding: 46px 0 28px;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) repeat(2, minmax(150px, 1fr));
  gap: 28px;
}

.site-footer h2,
.site-footer h3 {
  color: #fff;
}

.site-footer a {
  display: block;
  color: #cbd6e5;
  margin-top: 8px;
}

.footer-note {
  border-top: 1px solid rgba(255, 255, 255, .14);
  margin-top: 34px;
  padding-top: 20px;
  color: #93a4ba;
  font-size: 13px;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: none;
  align-items: center;
  justify-content: center;
  background: rgba(10, 17, 30, .62);
  padding: 24px;
}

.modal-backdrop.open {
  display: flex;
}

.modal {
  width: min(720px, 100%);
  max-height: min(92vh, 760px);
  overflow-y: auto;
  background: #fff;
  border-radius: 12px;
  border: 1px solid var(--line);
  box-shadow: 0 24px 72px rgba(0, 0, 0, .32);
}

.modal-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  padding: 24px 24px 12px;
}

.modal-head p {
  margin-top: 6px;
  color: var(--muted);
}

.modal-close {
  width: 40px;
  height: 40px;
  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: 12px 24px 24px;
}

.modal-actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 18px;
}

.modal .qr-card {
  background: #f8fbff;
}

.small {
  color: var(--muted);
  font-size: 13px;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 12px;
  background: #fff;
  color: var(--ink);
  padding: 8px 12px;
  z-index: 200;
  border: 1px solid var(--line);
}

.skip-link:focus {
  left: 12px;
}

@media (max-width: 980px) {
  .hero-grid,
  .media-row,
  .download-panel {
    grid-template-columns: 1fr;
  }

  .download-side {
    border-left: 0;
    border-top: 1px solid var(--line);
    padding-left: 0;
    padding-top: 24px;
  }

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

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

@media (max-width: 780px) {
  .container {
    width: min(100% - 28px, 1180px);
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav-wrap {
    min-height: 68px;
    flex-wrap: wrap;
  }

  .nav-links {
    order: 3;
    width: 100%;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding-bottom: 14px;
  }

  .site-header.menu-open .nav-links {
    display: flex;
  }

  .header-actions {
    display: none;
  }

  .hero {
    padding: 52px 0 34px;
  }

  .hero-grid {
    gap: 32px;
  }

  .proof-row,
  .grid-2,
  .grid-3,
  .grid-4,
  .modal-actions {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 54px 0;
  }

  .section-head {
    display: block;
  }

  .section-head p {
    margin-top: 12px;
  }

  .download-panel {
    padding: 20px;
  }

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

@media (max-width: 480px) {
  h1 {
    font-size: 34px;
  }

  .brand span {
    max-width: 190px;
    overflow-wrap: anywhere;
  }

  .btn {
    width: 100%;
  }

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

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

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