:root {
  color: #14212b;
  background: #f4f7f8;
  font-family: Inter, "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  --ink: #14212b;
  --navy: #0e2433;
  --navy-2: #173647;
  --muted: #60717f;
  --paper: #ffffff;
  --soft: #edf3f5;
  --line: #d9e3e8;
  --teal: #0f766e;
  --teal-dark: #075e59;
  --copper: #a25b26;
  --gold: #d6a34b;
  --shadow: 0 22px 60px rgba(14, 36, 51, 0.12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 320px; background: var(--soft); }
body, button, input, select, textarea { font: inherit; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
p { margin: 0; }

.skip-link {
  position: fixed;
  left: 16px;
  top: -80px;
  z-index: 100;
  padding: 10px 14px;
  color: #fff;
  background: var(--navy);
  border-radius: 6px;
}
.skip-link:focus { top: 12px; }

.seo-shell { min-height: 100vh; background: var(--soft); }
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  padding: 0 5vw;
  background: rgba(255, 255, 255, 0.96);
  border-bottom: 1px solid rgba(217, 227, 232, 0.9);
  box-shadow: 0 10px 30px rgba(14, 36, 51, 0.06);
  backdrop-filter: blur(14px);
}
.site-header nav {
  width: min(1220px, 100%);
  min-height: 70px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 28px;
}
.site-header nav a {
  padding: 8px 0;
  color: #445766;
  font-size: 0.9rem;
  font-weight: 760;
  border-bottom: 2px solid transparent;
  transition: color 160ms ease, border-color 160ms ease;
}
.site-header nav a:first-child {
  margin-right: auto;
  color: var(--navy);
  font-size: 1.08rem;
  font-weight: 900;
  letter-spacing: -0.02em;
}
.site-header nav a:first-child::before {
  content: "";
  display: inline-block;
  width: 24px;
  height: 9px;
  margin-right: 10px;
  border: 3px solid var(--teal);
  border-radius: 999px;
  vertical-align: 1px;
}
.site-header nav a:last-child {
  padding: 10px 14px;
  color: #fff;
  background: var(--teal);
  border: 0;
  border-radius: 7px;
}
.site-header nav a:hover,
.site-header nav a:focus-visible { color: var(--teal-dark); border-color: var(--teal); }
.site-header nav a:last-child:hover,
.site-header nav a:last-child:focus-visible { color: #fff; background: var(--teal-dark); }

main { overflow: hidden; }
.seo-hero {
  position: relative;
  isolation: isolate;
  min-height: 650px;
  padding: 92px max(5vw, calc((100vw - 1220px) / 2));
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(330px, 0.72fr);
  gap: clamp(36px, 6vw, 88px);
  align-items: center;
  color: #fff;
  background: var(--navy);
}
.seo-hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  inset: 0 0 0 58%;
  background: rgba(6, 20, 29, 0.28);
  border-left: 1px solid rgba(255, 255, 255, 0.13);
}
.seo-hero > div:first-child { max-width: 760px; }
.seo-kicker {
  margin-bottom: 15px;
  color: #f0bd61;
  font-size: 0.76rem;
  font-weight: 850;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.seo-hero h1 {
  max-width: 780px;
  margin: 0 0 22px;
  font-family: "Bahnschrift Condensed", "Arial Narrow", Inter, sans-serif;
  font-size: clamp(3.2rem, 6.2vw, 6.1rem);
  font-stretch: condensed;
  font-weight: 760;
  line-height: 0.96;
  letter-spacing: -0.045em;
}
.seo-hero p {
  max-width: 690px;
  color: rgba(255, 255, 255, 0.78);
  font-size: clamp(1rem, 1.5vw, 1.14rem);
  line-height: 1.78;
}
.seo-cta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 48px;
  margin-top: 28px;
  padding: 12px 19px;
  color: #fff;
  background: var(--teal);
  border-radius: 7px;
  box-shadow: 0 15px 32px rgba(15, 118, 110, 0.32);
  font-weight: 850;
  transition: transform 160ms ease, background 160ms ease;
}
.seo-cta::after { content: "→"; font-size: 1.1rem; }
.seo-cta:hover,
.seo-cta:focus-visible { background: var(--teal-dark); transform: translateY(-2px); }

.seo-hero > .seo-card {
  position: relative;
  min-height: 430px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  overflow: hidden;
  padding: 28px;
  color: #fff;
  background-color: #e6ecef;
  background-image: url("/assets/fiber-drum-slim.jpg");
  background-repeat: no-repeat;
  background-position: center 35%;
  background-size: contain;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 9px;
  box-shadow: 0 28px 70px rgba(0, 0, 0, 0.28);
}
.seo-hero > .seo-card::before {
  content: "";
  position: absolute;
  inset: 55% 0 0;
  background: rgba(9, 31, 43, 0.94);
}
.seo-hero > .seo-card strong,
.seo-hero > .seo-card span { position: relative; z-index: 1; }
.seo-hero > .seo-card strong {
  margin-bottom: 8px;
  color: #fff;
  font-size: 1.2rem;
}
.seo-hero > .seo-card span { color: rgba(255, 255, 255, 0.72); line-height: 1.65; }

.seo-specs {
  position: relative;
  z-index: 2;
  width: min(1120px, calc(100% - 10vw));
  margin: -42px auto 0;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border: 1px solid var(--line);
  background: var(--paper);
  box-shadow: var(--shadow);
}
.seo-specs .seo-card {
  min-height: 118px;
  padding: 24px;
  border-right: 1px solid var(--line);
}
.seo-specs .seo-card:last-child { border-right: 0; }
.seo-specs strong { display: block; margin-bottom: 8px; color: var(--navy); font-size: 1.55rem; }
.seo-specs span { color: var(--muted); line-height: 1.5; }

.seo-section,
.seo-columns {
  width: min(1120px, calc(100% - 10vw));
  margin: 0 auto;
}
.seo-section {
  position: relative;
  padding: 84px 0;
}
.seo-section + .seo-section { border-top: 1px solid var(--line); }
.seo-section h2 {
  max-width: 820px;
  margin: 0 0 24px;
  color: var(--ink);
  font-family: "Bahnschrift Condensed", "Arial Narrow", Inter, sans-serif;
  font-size: clamp(2.15rem, 4vw, 3.65rem);
  line-height: 1.04;
  letter-spacing: -0.035em;
}
.seo-section p,
.seo-section li {
  max-width: 880px;
  color: var(--muted);
  font-size: 1.02rem;
  line-height: 1.82;
}
.seo-section p + p { margin-top: 18px; }
.seo-section ul {
  max-width: 880px;
  margin: 30px 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}
.seo-section li {
  position: relative;
  min-height: 100px;
  padding: 22px 22px 22px 52px;
  background: var(--paper);
}
.seo-section li::before {
  content: "";
  position: absolute;
  left: 23px;
  top: 29px;
  width: 13px;
  height: 13px;
  border: 3px solid var(--teal);
  border-radius: 50%;
}
.seo-section a { color: var(--teal-dark); font-weight: 850; border-bottom: 1px solid rgba(15, 118, 110, 0.35); }
.seo-section a:hover,
.seo-section a:focus-visible { border-color: var(--teal); }

.seo-columns {
  padding: 16px 0 72px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}
.seo-columns .seo-card {
  min-height: 275px;
  padding: 28px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-top: 4px solid var(--teal);
  box-shadow: 0 14px 38px rgba(14, 36, 51, 0.07);
}
.seo-columns .seo-card:nth-child(2) { border-top-color: var(--copper); }
.seo-columns .seo-card:nth-child(3) { border-top-color: #4d6f8b; }
.seo-columns .seo-section { width: auto; margin: 0; }
.seo-columns h2 { margin: 0 0 15px; font-size: 1.55rem; letter-spacing: -0.02em; }
.seo-columns p { margin-bottom: 24px; font-size: 0.98rem; }

.quote-panel {
  width: min(1120px, calc(100% - 10vw));
  margin: 0 auto 84px;
  padding: 42px;
  color: #fff;
  background: var(--navy);
  border-radius: 9px;
  box-shadow: var(--shadow);
}
.quote-panel__heading { max-width: 760px; margin-bottom: 30px; }
.quote-panel h2 { margin: 0 0 12px; color: #fff; font-size: clamp(2rem, 3.5vw, 3.1rem); }
.quote-panel p { color: rgba(255, 255, 255, 0.7); line-height: 1.7; }
.quote-form { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.quote-form label { display: grid; gap: 8px; color: rgba(255, 255, 255, 0.86); font-size: 0.9rem; font-weight: 760; }
.quote-form input,
.quote-form select,
.quote-form textarea {
  width: 100%;
  min-height: 48px;
  padding: 12px 13px;
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 6px;
  outline: none;
}
.quote-form textarea { min-height: 130px; resize: vertical; }
.quote-form select option { color: var(--ink); background: #fff; }
.quote-form input::placeholder,
.quote-form textarea::placeholder { color: rgba(255, 255, 255, 0.42); }
.quote-form input:focus,
.quote-form select:focus,
.quote-form textarea:focus { border-color: var(--gold); box-shadow: 0 0 0 3px rgba(214, 163, 75, 0.15); }
.quote-form__wide { grid-column: 1 / -1; }
.quote-form button {
  width: fit-content;
  min-height: 48px;
  padding: 12px 20px;
  color: #fff;
  background: var(--teal);
  border: 0;
  border-radius: 7px;
  cursor: pointer;
  font-weight: 850;
}
.quote-form button:hover { background: var(--teal-dark); }
.quote-form button:disabled { cursor: wait; opacity: 0.65; }
.quote-form__message { min-height: 24px; margin-top: 2px; color: #bee8df; font-weight: 700; }
.quote-form__message[data-state="error"] { color: #fecaca; }
.form-honeypot { position: absolute !important; left: -10000px; width: 1px; height: 1px; overflow: hidden; }

.site-footer {
  padding: 30px 5vw;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px 28px;
  color: var(--muted);
  background: var(--paper);
  border-top: 1px solid var(--line);
  font-size: 0.88rem;
}
.site-footer p:first-child { font-weight: 720; }
.site-footer a { color: var(--teal-dark); }

@media (max-width: 980px) {
  .site-header nav { gap: 17px; }
  .seo-hero { grid-template-columns: minmax(0, 1fr) minmax(280px, 0.62fr); }
  .seo-columns { grid-template-columns: 1fr; }
  .seo-columns .seo-card { min-height: 0; }
}

@media (max-width: 760px) {
  .site-header { padding: 0 20px; }
  .site-header nav { min-height: 62px; overflow-x: auto; gap: 18px; }
  .site-header nav a { flex: 0 0 auto; }
  .site-header nav a:first-child { margin-right: 12px; }
  .site-header nav a:last-child { padding: 8px 11px; }
  .seo-hero { min-height: 0; padding: 68px 24px 54px; grid-template-columns: 1fr; gap: 30px; }
  .seo-hero::after { display: none; }
  .seo-hero h1 { font-size: clamp(2.75rem, 13vw, 4.3rem); }
  .seo-hero > .seo-card { min-height: 355px; }
  .seo-specs { width: calc(100% - 32px); grid-template-columns: repeat(2, minmax(0, 1fr)); margin-top: 16px; }
  .seo-specs .seo-card:nth-child(2) { border-right: 0; }
  .seo-specs .seo-card:nth-child(-n + 2) { border-bottom: 1px solid var(--line); }
  .seo-section,
  .seo-columns,
  .quote-panel { width: calc(100% - 40px); }
  .seo-section { padding: 62px 0; }
  .seo-section ul,
  .quote-form { grid-template-columns: 1fr; }
  .seo-columns { padding-bottom: 58px; }
  .quote-panel { margin-bottom: 62px; padding: 28px 20px; }
  .quote-form__wide { grid-column: auto; }
  .site-footer { padding: 26px 20px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}