:root {
  color-scheme: light;
  --ink: #111827;
  --muted: #647083;
  --line: #d9e4f2;
  --blue: #155fb2;
  --blue-deep: #0d3f7d;
  --blue-soft: #eaf3ff;
  --paper: #ffffff;
  --bg: #eef4fa;
  --gold: #b78b45;
  --shadow: 0 18px 48px rgba(21, 67, 117, 0.13);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
}
a { color: inherit; }
img { max-width: 100%; display: block; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(170, 196, 224, 0.55);
}
.nav {
  width: min(1120px, 100%);
  margin: 0 auto;
  padding: 13px 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: 0;
  text-decoration: none;
}
.brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  color: #fff;
  background: linear-gradient(135deg, var(--blue), #0c2f64);
  box-shadow: 0 8px 18px rgba(21, 95, 178, 0.22);
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 16px;
  color: #374151;
  font-size: 14px;
}
.nav-links a { text-decoration: none; }
.nav-cta {
  color: #fff !important;
  background: var(--blue);
  padding: 8px 13px;
  border-radius: 999px;
  font-weight: 700;
}

.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 15% 20%, rgba(42, 111, 190, 0.13), transparent 32%),
    linear-gradient(180deg, #ffffff 0%, #edf5ff 52%, #eef4fa 100%);
}
.hero-inner {
  width: min(1120px, 100%);
  margin: 0 auto;
  min-height: 0;
  padding: 48px 18px 52px;
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(310px, 0.98fr);
  gap: 42px;
  align-items: center;
}
.eyebrow {
  margin: 0 0 12px;
  color: var(--blue);
  font-weight: 800;
  letter-spacing: 0;
}
h1 {
  margin: 0;
  font-size: clamp(42px, 8vw, 82px);
  line-height: 1.05;
  letter-spacing: 0;
}
.hero-copy {
  margin: 20px 0 0;
  font-size: 19px;
  color: #3f4a5d;
  max-width: 660px;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 18px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 800;
  border: 1px solid transparent;
}
.button.primary { color: #fff; background: var(--blue); }
.button.secondary { color: var(--blue-deep); background: #fff; border-color: #bdd3ef; }
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
  color: #526075;
  font-size: 14px;
}
.hero-meta span {
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid #d9e5f4;
  border-radius: 999px;
  padding: 7px 11px;
}

.device-stage {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  align-items: stretch;
  max-height: min(620px, calc(100vh - 110px));
}
.product-photo {
  margin: 0;
  background: rgba(255, 255, 255, 0.86);
  border: 1px solid rgba(185, 207, 232, 0.9);
  border-radius: 18px;
  padding: 10px;
  box-shadow: var(--shadow);
  min-height: 0;
  overflow: hidden;
}
.product-photo.main {
  grid-column: 1 / -1;
  height: min(360px, 48vh);
}
.product-photo:not(.main) {
  height: min(220px, 28vh);
}
.product-photo img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 12px;
  background: #fff;
}

.section {
  width: min(1120px, 100%);
  margin: 0 auto;
  padding: 54px 18px;
}
.section-head {
  max-width: 760px;
  margin-bottom: 24px;
}
.section-title {
  margin: 0;
  font-size: clamp(28px, 5vw, 44px);
  line-height: 1.18;
}
.section-subtitle {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 17px;
}
.grid {
  display: grid;
  gap: 16px;
}
.grid.cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid.cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.feature-card, .panel {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 22px;
  box-shadow: 0 10px 28px rgba(22, 70, 124, 0.07);
}
.feature-card h3, .panel h3 {
  margin: 0 0 8px;
  font-size: 20px;
}
.feature-card p, .panel p {
  margin: 0;
  color: var(--muted);
}
.icon {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  margin-bottom: 14px;
  border-radius: 14px;
  background: var(--blue-soft);
  color: var(--blue);
  font-weight: 900;
}
.steps {
  counter-reset: step;
  display: grid;
  gap: 12px;
}
.step {
  counter-increment: step;
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 16px 16px 16px 58px;
}
.step::before {
  content: counter(step);
  position: absolute;
  left: 16px;
  top: 16px;
  width: 30px;
  height: 30px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  color: #fff;
  background: var(--blue);
  font-weight: 800;
}
.step h3 { margin: 0 0 4px; font-size: 18px; }
.step p { margin: 0; color: var(--muted); }

.manual-page {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 10px;
  box-shadow: var(--shadow);
}
.manual-page img { border-radius: 12px; }
.site-footer {
  background: #102033;
  color: #dbe8f6;
  padding: 34px 18px;
}
.footer-inner {
  width: min(1120px, 100%);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}
.footer-inner p { margin: 4px 0; color: #aebfd4; }

.start-header {
  background: linear-gradient(180deg, #ffffff 0%, #edf5ff 100%);
  border-bottom: 1px solid var(--line);
  padding: 34px 18px 26px;
  text-align: center;
}
.start-header h1 {
  font-size: clamp(34px, 9vw, 58px);
}
.start-main {
  width: min(980px, 100%);
  margin: 0 auto;
  padding: 18px;
}
.notice {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 16px 18px;
  margin-bottom: 16px;
  box-shadow: 0 8px 24px rgba(31, 77, 121, 0.08);
}
.notice strong { color: var(--blue); }
.manual-grid {
  display: grid;
  gap: 16px;
}
figure {
  margin: 0;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 10px;
  box-shadow: var(--shadow);
}
figure img { border-radius: 10px; width: 100%; }
figcaption {
  color: var(--muted);
  text-align: center;
  font-size: 14px;
  padding-top: 8px;
}
.sticky-actions {
  position: sticky;
  bottom: 0;
  display: flex;
  gap: 8px;
  justify-content: center;
  padding: 10px 8px max(10px, env(safe-area-inset-bottom));
  background: rgba(238, 244, 250, 0.92);
  backdrop-filter: blur(8px);
  border-top: 1px solid var(--line);
}
.sticky-actions .button { flex: 1; max-width: 220px; }

@media (max-width: 860px) {
  .nav-links a:not(.nav-cta) { display: none; }
  .hero-inner { grid-template-columns: 1fr; padding-top: 30px; padding-bottom: 36px; }
  .device-stage { grid-template-columns: 1fr; }
  .product-photo.main { grid-column: auto; }
  .product-photo.main, .product-photo:not(.main) { height: auto; max-height: none; }
  .product-photo img { max-height: 380px; }
  .grid.cols-3, .grid.cols-2 { grid-template-columns: 1fr; }
}
@media (min-width: 860px) {
  .manual-grid { grid-template-columns: 1fr 1fr; align-items: start; }
  .sticky-actions { position: static; background: transparent; border: 0; padding-bottom: 16px; }
}
@media print {
  .site-header, .start-header, .notice, .panel, .site-footer, .sticky-actions { display: none; }
  body { background: #fff; }
  .start-main { width: 100%; padding: 0; }
  figure { box-shadow: none; border: 0; padding: 0; page-break-after: always; }
}