:root {
  --bg: #f4f7fb;
  --surface: #ffffff;
  --surface-soft: #eef5fb;
  --ink: #0f172a;
  --muted: #475569;
  --line: #d7e2ed;
  --primary: #0f6cbd;
  --primary-dark: #0b4f8a;
  --primary-soft: #dbeafe;
  --accent: #0f766e;
  --warning: #b45309;
  --success: #15803d;
  --shadow: 0 18px 45px rgba(15, 23, 42, 0.08);
  --radius: 8px;
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.72;
}

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

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

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

button,
input,
select,
textarea {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid rgba(215, 226, 237, 0.9);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(16px);
}

.nav {
  width: min(100% - 40px, var(--max));
  min-height: 72px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  font-weight: 700;
  letter-spacing: 0;
  white-space: nowrap;
}

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

.brand span {
  display: block;
  font-size: 18px;
  line-height: 1.2;
}

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

.nav-links a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 12px;
  color: #334155;
  border-radius: 6px;
  font-size: 15px;
  font-weight: 600;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--primary);
  background: var(--primary-soft);
}

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

.mobile-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
}

.mobile-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  background: currentColor;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: 6px;
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}

.btn:hover {
  color: #fff;
  background: var(--primary-dark);
  box-shadow: 0 10px 24px rgba(15, 108, 189, 0.2);
  transform: translateY(-1px);
}

.btn.secondary {
  color: var(--primary);
  border-color: #b7d7f2;
  background: #fff;
}

.btn.secondary:hover {
  color: var(--primary-dark);
  background: #f0f7ff;
  box-shadow: none;
}

.btn.dark {
  background: #0f172a;
}

.btn.dark:hover {
  background: #1e293b;
}

.btn.small {
  min-height: 38px;
  padding: 0 14px;
  font-size: 14px;
}

.icon {
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
}

.hero {
  background: linear-gradient(180deg, #ffffff 0%, #f4f7fb 100%);
  border-bottom: 1px solid var(--line);
}

.hero-inner {
  width: min(100% - 40px, var(--max));
  margin: 0 auto;
  padding: 72px 0 42px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 0.92fr);
  gap: 48px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 16px;
  color: var(--primary-dark);
  font-size: 14px;
  font-weight: 800;
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 2px;
  background: var(--primary);
}

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

h1 {
  max-width: 780px;
  margin-bottom: 18px;
  font-size: 52px;
  line-height: 1.1;
  letter-spacing: 0;
}

.hero p {
  max-width: 720px;
  color: var(--muted);
  font-size: 19px;
}

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

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
  padding: 0;
  list-style: none;
}

.hero-meta li {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: #334155;
  font-size: 14px;
  font-weight: 700;
}

.hero-visual {
  position: relative;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  box-shadow: var(--shadow);
}

.hero-visual img {
  border-radius: 6px;
}

.section {
  padding: 72px 0;
  background: var(--surface);
}

.section.alt {
  background: var(--bg);
}

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

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

.section-head {
  max-width: 780px;
  margin-bottom: 34px;
}

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

.section-head h2,
.page-title h1 {
  margin-bottom: 12px;
  font-size: 36px;
  line-height: 1.2;
  letter-spacing: 0;
}

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

.page-title {
  padding: 56px 0 34px;
  border-bottom: 1px solid var(--line);
  background: #fff;
}

.page-title .container {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 28px;
  align-items: end;
}

.breadcrumb {
  color: #64748b;
  font-size: 14px;
  font-weight: 700;
}

.breadcrumb a {
  color: #64748b;
}

.grid {
  display: grid;
  gap: 18px;
}

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

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

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

.card,
.feature-card,
.stat-card,
.download-card,
.faq-item,
.timeline-item,
.guide-step {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.card,
.feature-card,
.download-card,
.guide-step {
  padding: 24px;
}

.feature-card h3,
.card h3,
.download-card h3,
.guide-step h3 {
  margin-bottom: 8px;
  font-size: 20px;
  line-height: 1.3;
}

.feature-card p,
.card p,
.download-card p,
.guide-step p {
  color: var(--muted);
  margin-bottom: 0;
}

.feature-icon {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  margin-bottom: 16px;
  border-radius: 8px;
  background: var(--primary-soft);
  color: var(--primary);
}

.feature-icon svg {
  width: 22px;
  height: 22px;
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.stat-card {
  padding: 22px;
}

.stat-card strong {
  display: block;
  color: var(--primary-dark);
  font-size: 28px;
  line-height: 1.1;
}

.stat-card span {
  display: block;
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

.band {
  background: #0f172a;
  color: #fff;
}

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

.band h2 {
  margin-bottom: 8px;
  font-size: 30px;
}

.band p {
  margin-bottom: 0;
  color: #cbd5e1;
}

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

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 760px;
}

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

th {
  background: #f8fafc;
  color: #334155;
  font-size: 14px;
}

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

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}

.tag-list li,
.pill {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #f8fafc;
  color: #334155;
  font-size: 13px;
  font-weight: 700;
}

.download-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 22px;
  align-items: start;
}

.download-card.featured {
  border-color: #b7d7f2;
  box-shadow: var(--shadow);
}

.download-meta {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 20px 0;
}

.download-meta div {
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #f8fafc;
}

.download-meta strong {
  display: block;
  font-size: 14px;
}

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

.notice {
  padding: 18px;
  border: 1px solid #fde68a;
  border-radius: var(--radius);
  background: #fffbeb;
  color: #78350f;
}

.notice p:last-child {
  margin-bottom: 0;
}

.steps {
  counter-reset: step;
}

.guide-step {
  position: relative;
  padding-left: 76px;
}

.guide-step::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 24px;
  top: 24px;
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: var(--primary);
  color: #fff;
  font-weight: 800;
}

.timeline {
  display: grid;
  gap: 14px;
}

.timeline-item {
  padding: 18px 20px;
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  gap: 20px;
}

.timeline-item time {
  color: var(--primary-dark);
  font-weight: 800;
}

.timeline-item h3 {
  margin-bottom: 6px;
  font-size: 18px;
}

.timeline-item p {
  margin-bottom: 0;
  color: var(--muted);
}

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

.faq-item {
  overflow: hidden;
}

.faq-question {
  width: 100%;
  min-height: 58px;
  padding: 0 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border: 0;
  background: #fff;
  color: var(--ink);
  text-align: left;
  font-weight: 800;
  cursor: pointer;
}

.faq-question svg {
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
  transition: transform 0.18s ease;
}

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

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

.faq-item.is-open .faq-question svg {
  transform: rotate(45deg);
}

.source-list {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
}

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

.site-footer {
  padding: 44px 0;
  border-top: 1px solid #1e293b;
  background: #0f172a;
  color: #cbd5e1;
}

.footer-grid {
  width: min(100% - 40px, var(--max));
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1fr) repeat(3, minmax(120px, 180px));
  gap: 28px;
}

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

.site-footer h2 {
  margin-bottom: 8px;
  font-size: 22px;
}

.site-footer h3 {
  margin-bottom: 10px;
  font-size: 15px;
}

.site-footer a {
  display: block;
  color: #cbd5e1;
  margin: 6px 0;
}

.site-footer a:hover {
  color: #fff;
}

.footer-note {
  width: min(100% - 40px, var(--max));
  margin: 28px auto 0;
  padding-top: 20px;
  border-top: 1px solid #334155;
  color: #94a3b8;
  font-size: 14px;
}

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

.modal.is-open {
  display: block;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(15, 23, 42, 0.62);
}

.modal-panel {
  position: relative;
  width: min(100% - 32px, 720px);
  max-height: calc(100vh - 40px);
  margin: 20px auto;
  overflow: auto;
  border-radius: var(--radius);
  background: #fff;
  box-shadow: 0 24px 80px rgba(15, 23, 42, 0.28);
}

.modal-head {
  padding: 22px 24px;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--line);
}

.modal-head h2 {
  margin-bottom: 4px;
  font-size: 24px;
}

.modal-head p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 14px;
}

.modal-close {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
  cursor: pointer;
}

.modal-body {
  padding: 24px;
}

.qr-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.qr-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #f8fafc;
  text-align: center;
}

.qr-card img {
  width: 190px;
  height: 190px;
  margin: 0 auto 14px;
  padding: 10px;
  border: 1px solid var(--line);
  background: #fff;
}

.qr-card h3 {
  margin-bottom: 6px;
  font-size: 18px;
}

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

.modal-foot {
  margin-top: 18px;
  padding: 14px;
  border-radius: 6px;
  background: #eef5fb;
  color: #334155;
  font-size: 14px;
}

.skip-link {
  position: absolute;
  top: -80px;
  left: 12px;
  z-index: 200;
  padding: 10px 12px;
  background: #fff;
  color: var(--ink);
  border: 1px solid var(--line);
}

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

:focus-visible {
  outline: 3px solid #93c5fd;
  outline-offset: 2px;
}

@media (max-width: 980px) {
  .hero-inner,
  .page-title .container,
  .download-layout,
  .band .container,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero-inner {
    padding-top: 54px;
  }

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

  .nav-actions .btn {
    display: none;
  }
}

@media (max-width: 760px) {
  .nav {
    width: min(100% - 28px, var(--max));
    min-height: 64px;
  }

  .mobile-toggle {
    display: inline-block;
  }

  .nav-links {
    position: absolute;
    left: 14px;
    right: 14px;
    top: 64px;
    display: none;
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: #fff;
    box-shadow: var(--shadow);
  }

  .nav-links.is-open {
    display: grid;
  }

  .nav-links a {
    justify-content: flex-start;
  }

  h1 {
    font-size: 38px;
  }

  .section-head h2,
  .page-title h1 {
    font-size: 30px;
  }

  .grid.two,
  .grid.three,
  .grid.four,
  .stat-row,
  .download-meta,
  .qr-grid {
    grid-template-columns: 1fr;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .guide-step {
    padding-left: 24px;
    padding-top: 72px;
  }

  .modal-panel {
    margin-top: 10px;
    max-height: calc(100vh - 20px);
  }
}

@media (max-width: 460px) {
  .container,
  .hero-inner,
  .footer-grid,
  .footer-note {
    width: min(100% - 28px, var(--max));
  }

  .hero-actions,
  .section-actions {
    display: grid;
  }

  .btn {
    width: 100%;
  }

  h1 {
    font-size: 32px;
  }

  .hero p {
    font-size: 17px;
  }
}