:root {
  --ink: #18313d;
  --muted: #5f7280;
  --soft: #f5f8f7;
  --line: #d9e5e4;
  --paper: #ffffff;
  --primary: #0f6f7a;
  --primary-strong: #0f3d4d;
  --accent: #d99a2b;
  --accent-soft: #fff4d8;
  --success: #1d8765;
  --danger: #b34242;
  --shadow: 0 18px 44px rgba(24, 49, 61, 0.12);
  --container: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

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

body.modal-open {
  overflow: hidden;
}

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

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

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(217, 229, 228, 0.9);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  font-weight: 800;
  letter-spacing: 0;
}

.brand-mark {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  background: var(--primary-strong);
  color: #fff;
  box-shadow: inset 0 -8px 0 rgba(255, 255, 255, 0.08);
}

.brand-mark svg {
  width: 24px;
  height: 24px;
}

.brand small {
  display: block;
  margin-top: -3px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 600;
}

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

.site-nav a {
  padding: 10px 13px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 700;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--primary-strong);
  background: var(--soft);
}

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

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.menu-toggle svg {
  width: 22px;
  height: 22px;
}

.button,
button.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: 6px;
  background: var(--primary);
  color: #fff;
  font: inherit;
  font-weight: 800;
  line-height: 1;
  cursor: pointer;
  transition: transform 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}

.button:hover,
button.button:hover {
  color: #fff;
  background: var(--primary-strong);
  transform: translateY(-1px);
}

.button svg {
  width: 18px;
  height: 18px;
}

.button.secondary {
  background: #fff;
  color: var(--primary-strong);
  border-color: var(--line);
}

.button.secondary:hover {
  color: var(--primary-strong);
  background: var(--soft);
}

.button.ghost {
  background: transparent;
  color: var(--primary-strong);
  border-color: var(--line);
}

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

.hero {
  padding: 78px 0 58px;
  background:
    linear-gradient(120deg, rgba(15, 111, 122, 0.1), transparent 52%),
    linear-gradient(0deg, #f8fbfa, #ffffff);
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(360px, 0.78fr);
  gap: 54px;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 18px;
  color: var(--primary-strong);
  font-weight: 800;
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 3px;
  border-radius: 999px;
  background: var(--accent);
}

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

h1 {
  max-width: 760px;
  font-size: clamp(40px, 6vw, 68px);
}

h2 {
  font-size: clamp(28px, 3.6vw, 42px);
}

h3 {
  font-size: 21px;
}

p {
  margin: 0;
}

.lead {
  max-width: 720px;
  margin-top: 22px;
  color: var(--muted);
  font-size: 18px;
}

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

.hero-note {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 28px;
  color: var(--muted);
  font-size: 14px;
}

.hero-note span {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.hero-note svg {
  width: 16px;
  height: 16px;
  color: var(--success);
}

.viewer-visual {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fdfefe;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.viewer-top {
  display: flex;
  gap: 8px;
  align-items: center;
  padding: 14px 16px;
  background: #edf5f4;
  border-bottom: 1px solid var(--line);
}

.window-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #98aaa9;
}

.viewer-title {
  margin-left: 8px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.viewer-body {
  display: grid;
  grid-template-columns: 112px 1fr;
  min-height: 350px;
}

.viewer-sidebar {
  padding: 18px 14px;
  border-right: 1px solid var(--line);
  background: #f6f9f8;
}

.viewer-line {
  height: 9px;
  margin-bottom: 12px;
  border-radius: 999px;
  background: #d6e4e3;
}

.viewer-page {
  display: grid;
  place-items: center;
  padding: 28px;
}

.paper-sheet {
  width: min(260px, 100%);
  min-height: 300px;
  padding: 34px 30px;
  border: 1px solid #dfe8e7;
  background: #fff;
  box-shadow: 0 14px 30px rgba(24, 49, 61, 0.1);
}

.paper-heading {
  width: 72%;
  height: 16px;
  margin-bottom: 22px;
  background: var(--primary);
}

.paper-line {
  height: 9px;
  margin-bottom: 12px;
  border-radius: 999px;
  background: #d9e5e4;
}

.paper-line.short {
  width: 64%;
}

.visual-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
}

.visual-stat {
  padding: 16px;
  border-right: 1px solid var(--line);
}

.visual-stat:last-child {
  border-right: 0;
}

.visual-stat strong {
  display: block;
  color: var(--primary-strong);
  font-size: 20px;
}

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

.section {
  padding: 76px 0;
}

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

.section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 28px;
  margin-bottom: 34px;
}

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

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

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

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

.card {
  min-width: 0;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.card p {
  margin-top: 12px;
  color: var(--muted);
}

.icon-box {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  margin-bottom: 18px;
  border-radius: 8px;
  background: #e8f5f4;
  color: var(--primary-strong);
}

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

.mini-kicker {
  display: inline-flex;
  margin-bottom: 12px;
  padding: 4px 9px;
  border-radius: 4px;
  background: var(--accent-soft);
  color: #7b5515;
  font-size: 13px;
  font-weight: 800;
}

.split {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 42px;
  align-items: start;
}

.check-list {
  display: grid;
  gap: 14px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  display: flex;
  gap: 10px;
  color: var(--muted);
}

.check-list svg {
  flex: 0 0 18px;
  width: 18px;
  height: 18px;
  margin-top: 4px;
  color: var(--success);
}

.workflow {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  overflow: hidden;
}

.workflow-step {
  padding: 28px;
  border-right: 1px solid var(--line);
}

.workflow-step:last-child {
  border-right: 0;
}

.step-number {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  margin-bottom: 16px;
  border-radius: 50%;
  background: var(--primary-strong);
  color: #fff;
  font-weight: 900;
}

.format-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.format-list span,
.tag {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
  color: var(--primary-strong);
  font-size: 14px;
  font-weight: 800;
}

.page-hero {
  padding: 58px 0 44px;
  background: linear-gradient(0deg, #f8fbfa, #ffffff);
  border-bottom: 1px solid var(--line);
}

.page-hero .lead {
  max-width: 780px;
}

.breadcrumb {
  margin-bottom: 18px;
  color: var(--muted);
  font-size: 14px;
}

.breadcrumb a {
  color: var(--muted);
}

.download-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 330px;
  gap: 24px;
  padding: 30px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  box-shadow: var(--shadow);
}

.version-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
  padding: 8px 12px;
  border-radius: 999px;
  background: #e8f5f4;
  color: var(--primary-strong);
  font-weight: 900;
}

.download-meta {
  display: grid;
  gap: 12px;
  align-content: start;
}

.meta-row {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
}

.meta-row span:first-child {
  color: var(--muted);
}

.meta-row strong {
  text-align: right;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

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

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

th {
  background: #f1f6f5;
  color: var(--primary-strong);
  font-size: 14px;
}

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

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

.notice {
  padding: 18px 20px;
  border-left: 4px solid var(--accent);
  border-radius: 6px;
  background: var(--accent-soft);
  color: #5d4214;
}

.feature-row {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 24px;
  padding: 28px 0;
  border-bottom: 1px solid var(--line);
}

.feature-row:last-child {
  border-bottom: 0;
}

.feature-row p {
  color: var(--muted);
}

.compare-table td:first-child,
.compare-table th:first-child {
  min-width: 180px;
}

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

.guide-step {
  position: relative;
  padding: 26px 26px 26px 76px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.guide-step::before {
  counter-increment: guide;
  content: counter(guide);
  position: absolute;
  left: 24px;
  top: 26px;
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--primary-strong);
  color: #fff;
  font-weight: 900;
}

.guide-step p {
  margin-top: 10px;
  color: var(--muted);
}

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

.shortcut {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

kbd {
  display: inline-flex;
  min-width: 44px;
  justify-content: center;
  padding: 4px 8px;
  border: 1px solid #cbd8d7;
  border-bottom-width: 2px;
  border-radius: 5px;
  background: #f7faf9;
  color: var(--primary-strong);
  font: 700 13px/1.2 Consolas, "Courier New", monospace;
}

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

.faq-item {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  overflow: hidden;
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 20px;
  border: 0;
  background: #fff;
  color: var(--ink);
  font: inherit;
  font-weight: 900;
  text-align: left;
  cursor: pointer;
}

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

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

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

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

.cta-band {
  padding: 42px;
  border-radius: 8px;
  background: var(--primary-strong);
  color: #fff;
}

.cta-band h2,
.cta-band p {
  color: #fff;
}

.cta-band p {
  max-width: 720px;
  margin-top: 14px;
  opacity: 0.86;
}

.cta-band .hero-actions {
  margin-top: 24px;
}

.site-footer {
  padding: 44px 0;
  border-top: 1px solid var(--line);
  background: #f8fbfa;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.2fr repeat(2, 0.7fr);
  gap: 26px;
}

.footer-grid h3 {
  font-size: 16px;
}

.footer-grid p,
.footer-grid a {
  color: var(--muted);
  font-size: 14px;
}

.footer-links {
  display: grid;
  gap: 8px;
  margin-top: 12px;
}

.copyright {
  margin-top: 34px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
  background: rgba(14, 28, 34, 0.58);
}

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

.download-modal {
  width: min(900px, 100%);
  max-height: min(720px, calc(100vh - 40px));
  overflow: auto;
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 28px 70px rgba(0, 0, 0, 0.25);
}

.modal-header {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 18px;
  padding: 24px 26px;
  border-bottom: 1px solid var(--line);
}

.modal-header p {
  margin-top: 7px;
  color: var(--muted);
}

.modal-close {
  width: 40px;
  height: 40px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
  cursor: pointer;
}

.modal-close svg {
  width: 18px;
  height: 18px;
}

.modal-body {
  padding: 26px;
}

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

.qr-card {
  display: grid;
  gap: 16px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8fbfa;
  text-align: center;
}

.qr-card img {
  width: 196px;
  height: 196px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  margin: 0 auto;
}

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

.modal-footnote {
  margin-top: 18px;
  color: var(--muted);
  font-size: 14px;
}

.source-list {
  display: grid;
  gap: 10px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.source-list li {
  display: flex;
  gap: 10px;
  color: var(--muted);
}

.source-list li::before {
  content: "";
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  margin-top: 10px;
  border-radius: 50%;
  background: var(--primary);
}

@media (max-width: 980px) {
  .nav-actions .button {
    display: none;
  }

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

  .site-nav {
    position: absolute;
    left: 20px;
    right: 20px;
    top: 72px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fff;
    box-shadow: var(--shadow);
  }

  .site-nav.open {
    display: flex;
  }

  .hero-grid,
  .split,
  .download-panel,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .grid.three,
  .grid.four,
  .workflow,
  .qr-grid {
    grid-template-columns: 1fr 1fr;
  }

  .workflow-step:nth-child(2) {
    border-right: 0;
  }

  .workflow-step:nth-child(3) {
    border-top: 1px solid var(--line);
  }

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

@media (max-width: 640px) {
  .container {
    width: min(100% - 28px, var(--container));
  }

  .hero {
    padding: 52px 0 44px;
  }

  h1 {
    font-size: 38px;
  }

  .section {
    padding: 54px 0;
  }

  .section-head {
    display: block;
  }

  .section-head p {
    margin-top: 14px;
  }

  .grid.three,
  .grid.four,
  .workflow,
  .qr-grid,
  .shortcut-grid,
  .visual-stats {
    grid-template-columns: 1fr;
  }

  .workflow-step,
  .workflow-step:nth-child(2),
  .workflow-step:nth-child(3),
  .visual-stat {
    border-right: 0;
    border-top: 1px solid var(--line);
  }

  .workflow-step:first-child,
  .visual-stat:first-child {
    border-top: 0;
  }

  .viewer-body {
    grid-template-columns: 1fr;
  }

  .viewer-sidebar {
    display: none;
  }

  .download-panel,
  .cta-band,
  .card,
  .guide-step {
    padding: 22px;
  }

  .guide-step {
    padding-left: 68px;
  }

  .hero-actions,
  .cta-band .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .button {
    width: 100%;
  }

  .qr-card img {
    width: 180px;
    height: 180px;
  }
}