:root {
  --blue-950: #082044;
  --blue-900: #0b2d5b;
  --blue-700: #145fb8;
  --blue-600: #1976d2;
  --cyan-500: #19b6d2;
  --cyan-100: #e7f9fd;
  --green-500: #15a779;
  --amber-500: #e5a623;
  --red-500: #d94a4a;
  --ink: #132033;
  --muted: #627188;
  --line: #dce8f4;
  --soft: #f4f8fc;
  --white: #ffffff;
  --shadow: 0 18px 50px rgba(8, 32, 68, .12);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

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

body.modal-open {
  overflow: hidden;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 14px clamp(20px, 5vw, 72px);
  background: rgba(255, 255, 255, .94);
  border-bottom: 1px solid rgba(220, 232, 244, .88);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--blue-950);
  font-weight: 800;
  letter-spacing: 0;
  white-space: nowrap;
}

.nav {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 15px;
  color: #41516a;
}

.nav a {
  position: relative;
  padding: 6px 0;
}

.nav a[aria-current="page"],
.nav a:hover {
  color: var(--blue-700);
}

.nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--cyan-500);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font: inherit;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: transform .18s ease, box-shadow .18s ease, background .18s ease, border-color .18s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  color: var(--white);
  background: linear-gradient(135deg, var(--blue-700), var(--cyan-500));
  box-shadow: 0 10px 24px rgba(20, 95, 184, .22);
}

.btn-secondary {
  color: var(--blue-900);
  border-color: var(--line);
  background: var(--white);
}

.btn-light {
  color: var(--blue-900);
  background: var(--white);
  box-shadow: none;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, .95fr) minmax(420px, 1.05fr);
  align-items: center;
  gap: clamp(36px, 6vw, 78px);
  padding: clamp(44px, 6.4vw, 72px) clamp(20px, 5vw, 72px) 40px;
  background:
    linear-gradient(125deg, rgba(231, 249, 253, .86), rgba(255, 255, 255, .86) 42%, rgba(242, 247, 252, .95)),
    linear-gradient(180deg, #ffffff, #f8fbfe);
}

.hero-copy h1,
.page-hero h1 {
  margin: 0;
  color: var(--blue-950);
  font-size: clamp(38px, 5.4vw, 68px);
  line-height: 1.08;
  letter-spacing: 0;
}

.hero-copy p,
.page-hero p {
  max-width: 700px;
  margin: 24px 0 0;
  color: #43526a;
  font-size: 18px;
}

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

.hero-facts {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  max-width: 560px;
  margin: 28px 0 0;
}

.hero-facts div {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, .76);
}

.hero-facts dt {
  color: var(--muted);
  font-size: 13px;
}

.hero-facts dd {
  margin: 4px 0 0;
  color: var(--blue-950);
  font-weight: 800;
}

.hero-visual {
  min-width: 0;
}

.hero-visual img {
  width: 100%;
  filter: drop-shadow(0 28px 42px rgba(8, 32, 68, .18));
}

.section {
  padding: clamp(64px, 8vw, 104px) clamp(20px, 5vw, 72px);
}

.section-tight {
  padding-top: 78px;
}

.section-heading {
  max-width: 820px;
  margin-bottom: 34px;
}

.section-heading h2,
.scene-copy h2,
.cta-band h2,
.two-column h2,
.info-table-wrap h2,
.source-note h2,
.help-content h2 {
  margin: 0;
  color: var(--blue-950);
  font-size: clamp(28px, 3.4vw, 42px);
  line-height: 1.18;
  letter-spacing: 0;
}

.section-heading p,
.scene-copy p,
.cta-band p,
.two-column p,
.source-note p,
.help-content p {
  margin: 14px 0 0;
  color: var(--muted);
}

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

.feature-strip article,
.detail-list article,
.review-grid article,
.scene-grid article,
.checklist-grid div,
.download-box {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.feature-strip article {
  padding: 26px;
}

.icon-dot {
  display: block;
  width: 32px;
  height: 32px;
  margin-bottom: 18px;
  border-radius: 50%;
  background:
    radial-gradient(circle at 35% 35%, #ffffff 0 20%, transparent 21%),
    linear-gradient(135deg, var(--blue-700), var(--cyan-500));
}

h2,
h3,
p {
  overflow-wrap: anywhere;
}

h3 {
  margin: 0 0 10px;
  color: var(--blue-950);
  font-size: 20px;
  line-height: 1.3;
}

article p {
  margin: 0;
  color: var(--muted);
}

.scene-band {
  display: grid;
  grid-template-columns: .78fr 1.22fr;
  gap: 44px;
  padding: clamp(64px, 8vw, 100px) clamp(20px, 5vw, 72px);
  color: var(--white);
  background:
    linear-gradient(135deg, rgba(8, 32, 68, .96), rgba(11, 45, 91, .94)),
    var(--blue-950);
}

.scene-copy h2,
.scene-copy p {
  color: var(--white);
}

.scene-copy p {
  opacity: .78;
}

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

.scene-grid article {
  padding: 24px;
  border-color: rgba(255, 255, 255, .16);
  background: rgba(255, 255, 255, .08);
}

.scene-grid h3,
.scene-grid p {
  color: var(--white);
}

.scene-grid p {
  opacity: .78;
}

.reviews {
  background: var(--soft);
}

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

.review-grid article {
  min-height: 220px;
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-grid p {
  color: #263850;
  font-size: 17px;
}

.review-grid strong {
  margin-top: 24px;
  color: var(--blue-700);
}

.cta-band {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 26px;
  margin: 0 clamp(20px, 5vw, 72px) clamp(64px, 8vw, 96px);
  padding: clamp(34px, 5vw, 52px);
  color: var(--white);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, var(--blue-900), var(--blue-700) 68%, var(--cyan-500));
}

.cta-band h2,
.cta-band p {
  color: var(--white);
}

.page-hero {
  padding: clamp(58px, 8vw, 92px) clamp(20px, 5vw, 72px);
  background: linear-gradient(135deg, var(--cyan-100), #ffffff 62%, #f5f9fd);
}

.download-hero .btn {
  margin-top: 28px;
}

.two-column {
  display: grid;
  grid-template-columns: .72fr 1.28fr;
  gap: clamp(32px, 6vw, 70px);
}

.detail-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.detail-list article {
  padding: 24px;
}

.info-table-wrap {
  padding-top: 0;
}

.info-table {
  width: 100%;
  border-collapse: collapse;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow);
}

.info-table th,
.info-table td {
  padding: 18px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.info-table th {
  width: 24%;
  color: var(--blue-950);
  background: #f7fbff;
}

.info-table td {
  color: #3d4c62;
}

.workflow {
  display: grid;
  gap: 18px;
  padding: clamp(56px, 8vw, 92px) clamp(20px, 5vw, 72px);
}

.workflow article {
  display: grid;
  grid-template-columns: 86px 260px 1fr;
  gap: 24px;
  align-items: start;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.workflow span {
  color: var(--cyan-500);
  font-size: 28px;
  font-weight: 900;
}

.workflow h2 {
  margin: 0;
  color: var(--blue-950);
  font-size: 24px;
}

.workflow p {
  margin: 0;
  color: var(--muted);
}

.checklist-section {
  background: var(--soft);
}

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

.checklist-grid div {
  padding: 22px;
}

.checklist-grid strong {
  color: var(--blue-950);
}

.checklist-grid p {
  margin: 8px 0 0;
  color: var(--muted);
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.download-box {
  display: grid;
  justify-items: start;
  gap: 14px;
  padding: 30px;
  box-shadow: var(--shadow);
}

.download-box img {
  width: 148px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.download-box h2 {
  margin: 10px 0 0;
  color: var(--blue-950);
}

.download-box p {
  margin: 0;
  color: var(--muted);
}

.source-note {
  padding-top: 0;
}

.source-note ul {
  margin: 18px 0 0;
  padding-left: 20px;
  color: var(--blue-700);
}

.help-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 44px;
}

.help-nav {
  position: sticky;
  top: 94px;
  align-self: start;
  display: grid;
  gap: 8px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.help-nav a {
  padding: 10px 12px;
  border-radius: 6px;
  color: #44546b;
}

.help-nav a:hover {
  color: var(--blue-700);
  background: var(--cyan-100);
}

.help-content {
  display: grid;
  gap: 42px;
}

.faq-list details {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

.faq-list details + details {
  margin-top: 12px;
}

.faq-list summary {
  cursor: pointer;
  padding: 18px 20px;
  color: var(--blue-950);
  font-weight: 800;
}

.faq-list details p {
  margin: 0;
  padding: 0 20px 20px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 32px;
  padding: 36px clamp(20px, 5vw, 72px);
  color: #c7d4e3;
  background: var(--blue-950);
}

.site-footer p {
  max-width: 680px;
  margin: 8px 0 0;
  color: #9fb2ca;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  align-content: start;
}

.site-footer a:hover {
  color: var(--white);
}

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

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

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(8, 32, 68, .62);
}

.modal-panel {
  position: relative;
  width: min(680px, calc(100vw - 32px));
  margin: min(11vh, 92px) auto 0;
  padding: 34px;
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: 0 30px 90px rgba(0, 0, 0, .24);
}

.modal-panel h2 {
  margin: 0;
  color: var(--blue-950);
  font-size: 30px;
}

.modal-panel p {
  margin: 10px 0 24px;
  color: var(--muted);
}

.modal-close {
  position: absolute;
  top: 14px;
  right: 14px;
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  border-radius: 50%;
  color: var(--blue-950);
  background: var(--white);
  font-size: 26px;
  line-height: 1;
  cursor: pointer;
}

.download-options {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.download-card {
  display: grid;
  justify-items: center;
  gap: 12px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #f8fbfe;
  color: var(--blue-950);
  font-weight: 800;
}

.download-card img {
  width: 154px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
}

@media (max-width: 980px) {
  .site-header {
    flex-wrap: wrap;
  }

  .nav {
    order: 3;
    width: 100%;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .hero,
  .scene-band,
  .two-column,
  .help-layout {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .hero-visual {
    max-width: 760px;
  }

  .workflow article {
    grid-template-columns: 70px 1fr;
  }

  .workflow article p {
    grid-column: 2;
  }
}

@media (max-width: 720px) {
  .site-header {
    padding: 12px 16px;
  }

  .brand span {
    font-size: 16px;
  }

  .site-header > .btn {
    min-height: 40px;
    padding: 0 14px;
  }

  .hero,
  .page-hero,
  .section,
  .scene-band,
  .workflow {
    padding-left: 16px;
    padding-right: 16px;
  }

  .hero-copy h1,
  .page-hero h1 {
    font-size: 36px;
  }

  .hero-copy p,
  .page-hero p {
    font-size: 16px;
  }

  .hero-facts,
  .feature-strip,
  .scene-grid,
  .review-grid,
  .detail-list,
  .checklist-grid,
  .download-grid,
  .download-options {
    grid-template-columns: 1fr;
  }

  .cta-band,
  .site-footer {
    flex-direction: column;
    align-items: stretch;
  }

  .cta-band {
    margin-left: 16px;
    margin-right: 16px;
  }

  .workflow article {
    grid-template-columns: 1fr;
  }

  .workflow article p {
    grid-column: auto;
  }

  .info-table {
    display: block;
    overflow-x: auto;
  }

  .modal-panel {
    padding: 28px 18px;
  }
}