/* about.html */
:root {
  --ink: #111827;
  --ink-soft: #334155;
  --muted: #64748b;
  --line: #e2e8f0;
  --surface: #ffffff;
  --surface-soft: #f8fafc;
  --surface-blue: #eef6ff;
  --blue: #2563eb;
  --cyan: #0891b2;
  --green: #059669;
  --amber: #b7791f;
  --shadow: 0 18px 54px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  background: #ffffff;
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.72;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

.top-navbar {
  position: sticky;
  top: 0;
  z-index: 20;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 clamp(18px, 4vw, 44px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.86);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
}

.nav-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-size: 18px;
  font-weight: 850;
  white-space: nowrap;
}

.nav-logo img {
  width: 30px;
  height: 30px;
  object-fit: contain;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 24px);
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
}

.nav-links a {
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--ink);
}

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

.hero-section {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(360px, 0.98fr);
  gap: clamp(34px, 6vw, 72px);
  align-items: center;
  min-height: calc(100vh - 68px);
  padding: clamp(52px, 8vw, 88px) 0 clamp(36px, 6vw, 70px);
}

.eyebrow,
.section-kicker {
  color: var(--cyan);
  font-size: 12px;
  font-weight: 850;
  letter-spacing: 0;
  margin-bottom: 12px;
  text-transform: uppercase;
}

h1 {
  max-width: 780px;
  color: var(--ink);
  font-size: clamp(38px, 5.7vw, 72px);
  font-weight: 880;
  line-height: 1.04;
  letter-spacing: 0;
  margin-bottom: 22px;
}

.lead {
  max-width: 740px;
  color: var(--ink-soft);
  font-size: clamp(16px, 1.45vw, 19px);
  line-height: 1.8;
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 800;
  text-decoration: none;
  transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

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

.button-primary {
  border: 1px solid #0f172a;
  background: #0f172a;
  color: #ffffff;
}

.button-secondary {
  border: 1px solid var(--line);
  background: #ffffff;
  color: var(--ink);
}

.hero-visual {
  display: grid;
  grid-template-columns: 1fr 0.58fr;
  gap: 14px;
  align-items: stretch;
}

.visual-main,
.visual-stack img {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-soft);
  box-shadow: var(--shadow);
}

.visual-main {
  min-height: 420px;
  aspect-ratio: 4 / 5;
}

.visual-main img,
.visual-stack img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.visual-main figcaption {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.visual-stack {
  display: grid;
  gap: 14px;
}

.visual-stack img {
  aspect-ratio: 1 / 1;
}

.entity-section,
.matrix-section,
.workflow-section,
.audience-section,
.answer-section,
.faq-section,
.contact-section {
  padding: clamp(58px, 8vw, 92px) 0;
  border-top: 1px solid var(--line);
}

.section-heading {
  max-width: 820px;
  margin-bottom: 26px;
}

h2 {
  color: var(--ink);
  font-size: clamp(28px, 3.3vw, 42px);
  font-weight: 850;
  line-height: 1.16;
  letter-spacing: 0;
}

.section-heading p:not(.section-kicker) {
  margin-top: 12px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
}

.entity-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.74fr);
  gap: 18px;
  align-items: stretch;
}

.quote-panel,
.facts-panel,
.product-card,
.audience-grid article,
.answer-grid article,
.faq-list details,
.contact-section {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.quote-panel {
  padding: clamp(24px, 4vw, 40px);
  background: var(--surface-blue);
}

.quote-panel p {
  color: #12304f;
  font-size: clamp(18px, 2.1vw, 26px);
  font-weight: 780;
  line-height: 1.55;
}

.facts-panel {
  padding: 24px;
  background: #ffffff;
}

.facts-panel dl {
  display: grid;
  gap: 16px;
}

.facts-panel div {
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.facts-panel div:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.facts-panel dt {
  color: var(--muted);
  font-size: 12px;
  font-weight: 800;
  margin-bottom: 4px;
}

.facts-panel dd {
  color: var(--ink);
  font-size: 15px;
  font-weight: 720;
}

.facts-panel a {
  color: var(--blue);
  text-decoration: none;
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.product-card {
  min-height: 230px;
  padding: 22px;
  color: var(--ink);
  text-decoration: none;
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

.product-card:hover {
  transform: translateY(-2px);
  border-color: #bfdbfe;
  box-shadow: 0 18px 44px rgba(37, 99, 235, 0.10);
}

.product-card span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 28px;
  margin-bottom: 20px;
  border: 1px solid #bfdbfe;
  border-radius: 8px;
  color: var(--blue);
  background: #eff6ff;
  font-size: 12px;
  font-weight: 850;
}

.product-card h3,
.audience-grid h3,
.answer-grid h3 {
  color: var(--ink);
  font-size: 18px;
  line-height: 1.35;
  margin-bottom: 10px;
}

.product-card p,
.audience-grid p,
.answer-grid p,
.workflow-list p,
.faq-list p,
.contact-section p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.82;
}

.workflow-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  list-style: none;
  counter-reset: workflow;
}

.workflow-list li {
  position: relative;
  min-height: 220px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  counter-increment: workflow;
}

.workflow-list li::before {
  content: counter(workflow, decimal-leading-zero);
  display: block;
  color: var(--green);
  font-size: 13px;
  font-weight: 900;
  margin-bottom: 44px;
}

.workflow-list strong {
  display: block;
  color: var(--ink);
  font-size: 17px;
  margin-bottom: 8px;
}

.audience-grid,
.answer-grid {
  display: grid;
  gap: 16px;
}

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

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

.audience-grid article,
.answer-grid article {
  padding: 22px;
}

.answer-grid article:nth-child(1) {
  border-color: #bfdbfe;
  background: #eff6ff;
}

.answer-grid article:nth-child(2) {
  border-color: #bae6fd;
  background: #f0f9ff;
}

.answer-grid article:nth-child(3) {
  border-color: #bbf7d0;
  background: #f0fdf4;
}

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

.faq-list details {
  padding: 18px 20px;
}

.faq-list summary {
  cursor: pointer;
  color: var(--ink);
  font-size: 16px;
  font-weight: 800;
  list-style: none;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  content: "+";
  float: right;
  color: var(--blue);
  font-weight: 800;
}

.faq-list details[open] summary::after {
  content: "-";
}

.faq-list p {
  margin-top: 12px;
  max-width: 880px;
}

.contact-section {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 30px;
  margin-bottom: 76px;
  background: #0f172a;
}

.contact-section h2,
.contact-section p,
.contact-section .section-kicker {
  color: #ffffff;
}

.contact-section p {
  opacity: 0.78;
  margin-top: 8px;
}

footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  padding: 28px 20px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

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

footer a:hover {
  color: var(--ink);
}

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

  .hero-section {
    min-height: auto;
  }

  .hero-visual {
    grid-template-columns: 1fr;
  }

  .visual-main {
    min-height: 320px;
    aspect-ratio: 16 / 10;
  }

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

  .product-grid,
  .workflow-list,
  .audience-grid,
  .answer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .top-navbar {
    height: auto;
    min-height: 62px;
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 18px;
  }

  .nav-links {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  main {
    width: calc(100% - 28px);
  }

  .hero-section {
    padding-top: 38px;
  }

  .hero-actions,
  .contact-section,
  footer {
    flex-direction: column;
    align-items: stretch;
  }

  .button {
    width: 100%;
  }

  .visual-stack,
  .product-grid,
  .workflow-list,
  .audience-grid,
  .answer-grid {
    grid-template-columns: 1fr;
  }

  .product-card,
  .workflow-list li {
    min-height: auto;
  }
}