:root {
  --ink: #16201c;
  --ink-soft: #52605a;
  --paper: #f7f8f4;
  --white: #ffffff;
  --line: #dfe4dd;
  --accent: #1e5b43;
  --accent-bright: #a9e7c5;
  --accent-pale: #e9f3ed;
  --dark: #17382b;
  --radius: 18px;
  --shadow: 0 18px 50px rgba(25, 55, 43, 0.08);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 100;
  padding: 8px 12px;
  color: var(--white);
  background: var(--ink);
  border-radius: 6px;
  transform: translateY(-160%);
}

.skip-link:focus { transform: translateY(0); }

.shell {
  width: min(1160px, calc(100% - 40px));
  margin-inline: auto;
}

.site-header {
  position: relative;
  z-index: 10;
  border-bottom: 1px solid rgba(22, 32, 28, 0.08);
  background: rgba(247, 248, 244, 0.94);
}

.header-inner {
  min-height: 78px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
}

.brand-mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  color: var(--white);
  background: var(--accent);
  border-radius: 10px;
  font-size: 18px;
  font-weight: 800;
  line-height: 1;
}

.brand-copy { display: grid; line-height: 1.25; }
.brand-copy strong { font-size: 16px; letter-spacing: 0.08em; }
.brand-copy small { margin-top: 3px; color: var(--ink-soft); font-size: 10px; }

.header-link {
  color: var(--ink-soft);
  font-size: 14px;
  font-weight: 650;
  text-underline-offset: 5px;
  text-decoration-thickness: 1px;
}

.hero {
  padding: 72px 0 80px;
  overflow: hidden;
}

.hero-grid { display: grid; gap: 48px; }

.eyebrow,
.section-index {
  margin: 0 0 18px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.eyebrow { display: flex; align-items: center; gap: 9px; }
.eyebrow span { width: 7px; height: 7px; background: var(--accent); border-radius: 50%; }

h1,
h2,
p { margin-top: 0; }

h1 {
  max-width: 720px;
  margin-bottom: 25px;
  font-size: clamp(52px, 14vw, 84px);
  font-weight: 760;
  letter-spacing: -0.065em;
  line-height: 0.99;
}

h2 {
  margin-bottom: 20px;
  font-size: clamp(32px, 8.5vw, 52px);
  font-weight: 730;
  letter-spacing: -0.045em;
  line-height: 1.12;
}

.hero-lead {
  max-width: 600px;
  margin-bottom: 18px;
  font-size: clamp(21px, 5.5vw, 30px);
  letter-spacing: -0.025em;
  line-height: 1.4;
}

.hero-lead strong { color: var(--accent); font-weight: 760; }

.hero-description {
  max-width: 650px;
  margin-bottom: 30px;
  color: var(--ink-soft);
  font-size: 16px;
}

.hero-actions { display: flex; flex-direction: column; align-items: flex-start; gap: 16px; }

.button {
  min-height: 52px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 34px;
  padding: 12px 21px;
  color: var(--white);
  background: var(--accent);
  border: 2px solid var(--accent);
  border-radius: 9px;
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  transition: color 160ms ease, background 160ms ease, transform 160ms ease;
}

.button:hover { color: var(--accent); background: transparent; transform: translateY(-1px); }
.button:focus-visible, .header-link:focus-visible, .brand:focus-visible { outline: 3px solid var(--accent-bright); outline-offset: 4px; }
.hero-actions p { margin: 0; color: var(--ink-soft); font-size: 12px; line-height: 1.55; }

.signal-card {
  position: relative;
  padding: 24px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 22px;
  box-shadow: var(--shadow);
}

.signal-card::before {
  content: "";
  position: absolute;
  top: -24px;
  right: -24px;
  width: 92px;
  height: 92px;
  border: 1px solid rgba(30, 91, 67, 0.17);
  border-radius: 50%;
  z-index: -1;
}

.signal-top {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 18px;
  color: var(--ink-soft);
  border-bottom: 1px solid var(--line);
  font-size: 11px;
  font-weight: 650;
  letter-spacing: 0.08em;
}

.status-dot { width: 7px; height: 7px; background: #4cb980; border-radius: 50%; box-shadow: 0 0 0 4px #e8f6ef; }
.scene-note {
  margin-left: auto;
  padding: 2px 6px;
  color: var(--accent);
  background: var(--accent-pale);
  border-radius: 999px;
  font-size: 9px;
  letter-spacing: 0;
  white-space: nowrap;
}

.signal-code { color: #87938d; }

.question-bubble {
  margin: 30px 0 27px;
  padding: 20px;
  background: var(--accent-pale);
  border-radius: 14px 14px 14px 4px;
}

.bubble-label { display: block; margin-bottom: 8px; color: var(--accent); font-size: 11px; font-weight: 750; }
.question-bubble p { margin: 0; font-size: 18px; font-weight: 680; letter-spacing: -0.015em; line-height: 1.45; }

.scan-line { position: relative; height: 1px; background: var(--line); }
.scan-line span { position: absolute; top: -2px; left: 18%; width: 34%; height: 5px; background: var(--accent); border-radius: 4px; }

.signal-result { padding: 24px 2px 22px; }
.signal-result span { display: block; margin-bottom: 7px; color: var(--ink-soft); font-size: 11px; }
.signal-result strong { display: block; font-size: 17px; line-height: 1.5; }

.platform-row { display: grid; grid-template-columns: 1fr 1fr; gap: 7px; }
.platform-row span { padding: 9px; color: var(--ink-soft); background: #f5f7f4; border-radius: 7px; font-size: 11px; text-align: center; }

.section { padding: 82px 0; }
.scene-section { background: var(--white); }
.section-heading { margin-bottom: 38px; }
.section-heading h2 { margin-bottom: 0; }
.section-heading > p:last-child { max-width: 460px; margin-bottom: 0; color: var(--ink-soft); }

.question-grid { display: grid; gap: 12px; }
.question-grid blockquote {
  margin: 0;
  padding: 19px 20px;
  background: var(--paper);
  border: 1px solid transparent;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 630;
  line-height: 1.5;
}

.scene-callout {
  margin: 24px 0 0;
  padding: 20px;
  color: var(--white);
  background: var(--accent);
  border-radius: 12px;
  font-size: 17px;
  text-align: center;
}

.check-grid {
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
  list-style: none;
  counter-reset: none;
}

.check-grid li {
  min-height: 168px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 20px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 15px;
}

.check-grid span { color: var(--accent); font-size: 11px; font-weight: 750; }
.check-grid strong { font-size: 20px; line-height: 1.42; }
.support-note { max-width: 700px; margin: 22px 0 0; color: var(--ink-soft); font-size: 13px; }

.platform-section { padding: 82px 0; color: var(--white); background: var(--dark); }
.section-index.light { color: var(--accent-bright); }
.platform-layout > div > p:last-child { max-width: 480px; margin-bottom: 0; color: #bdcec5; }
.platform-list { margin: 40px 0 0; padding: 0; list-style: none; border-top: 1px solid rgba(255,255,255,0.16); }
.platform-list li { display: flex; align-items: center; justify-content: space-between; padding: 16px 0; border-bottom: 1px solid rgba(255,255,255,0.16); font-size: 18px; font-weight: 650; }
.platform-list span { color: #9eb0a7; font-size: 11px; font-weight: 600; }

.steps { margin: 0; padding: 0; display: grid; gap: 13px; list-style: none; }
.steps li { position: relative; padding: 24px; background: var(--white); border: 1px solid var(--line); border-radius: 15px; }
.step-number { display: block; margin-bottom: 30px; color: var(--accent); font-size: 11px; font-weight: 750; }
.steps strong { display: block; margin-bottom: 8px; font-size: 18px; line-height: 1.5; }
.steps p { margin: 0; color: var(--ink-soft); font-size: 13px; }

.audience-section { background: var(--white); }
.tag-list { margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 9px; list-style: none; }
.tag-list li { padding: 9px 13px; color: var(--accent); background: var(--accent-pale); border-radius: 999px; font-size: 13px; font-weight: 650; }
.audience-note { max-width: 620px; margin: 22px 0 0; color: var(--ink-soft); font-size: 13px; }

.test-note-card { padding: 26px; background: #edf1eb; border: 1px solid #d8dfd6; border-radius: var(--radius); }
.test-note-card h2 { font-size: clamp(29px, 7.8vw, 44px); }
.test-note-copy p { margin-bottom: 14px; color: var(--ink-soft); font-size: 14px; }
.test-note-copy p:last-child { margin-bottom: 0; color: var(--ink); font-weight: 600; }

.about-section { color: var(--white); background: var(--accent); }
.about-section .section-index { color: var(--accent-bright); }
.about-copy p { color: #dcebe3; }
.about-copy .about-lead { margin-bottom: 16px; color: var(--white); font-size: 21px; font-weight: 620; line-height: 1.55; }
.about-copy p:last-child { margin-bottom: 0; }

.operator-section { padding: 82px 0; background: var(--white); }
.operator-grid h2 { max-width: 470px; font-size: clamp(28px, 7vw, 43px); }
.operator-facts { margin: 34px 0 0; }
.operator-facts div { padding: 15px 0; display: grid; grid-template-columns: minmax(94px, 0.8fr) 1.3fr; gap: 14px; border-bottom: 1px solid var(--line); }
.operator-facts dt { color: var(--ink-soft); font-size: 13px; }
.operator-facts dd { margin: 0; font-size: 14px; font-weight: 650; text-align: right; }

.contact-section { padding: 30px 0 82px; background: var(--white); }
.contact-card { padding: 28px; color: var(--white); background: var(--dark); border-radius: var(--radius); }
.contact-card h2 { max-width: 570px; margin-bottom: 28px; }
.contact-placeholder { padding-top: 22px; border-top: 1px solid rgba(255,255,255,0.17); }
.contact-placeholder span { display: block; color: #aebfb6; font-size: 11px; }
.contact-placeholder strong { display: block; margin: 5px 0; color: var(--accent-bright); font-size: 18px; }
.contact-placeholder p { margin: 0; color: #aebfb6; font-size: 12px; }

.site-footer { padding: 42px 0; color: #c5d1cb; background: #10271e; }
.footer-inner { display: grid; gap: 28px; }
.footer-inner strong { color: var(--white); font-size: 18px; letter-spacing: 0.08em; }
.footer-inner p { margin: 5px 0 0; font-size: 12px; }
.footer-meta { padding-top: 24px; border-top: 1px solid rgba(255,255,255,0.13); }

@media (min-width: 680px) {
  .shell { width: min(1160px, calc(100% - 72px)); }
  .hero { padding: 92px 0 100px; }
  .hero-grid { grid-template-columns: minmax(0, 1.25fr) minmax(310px, 0.75fr); align-items: center; gap: 56px; }
  .hero-actions { flex-direction: row; align-items: center; gap: 22px; }
  .question-grid, .check-grid { grid-template-columns: repeat(2, 1fr); }
  .split-heading { display: grid; grid-template-columns: 1.15fr 0.85fr; align-items: end; gap: 50px; }
  .platform-layout { display: grid; grid-template-columns: 1fr 0.9fr; align-items: center; gap: 90px; }
  .platform-list { margin-top: 0; }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .audience-layout, .about-grid, .operator-grid { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 76px; }
  .operator-facts { margin-top: 0; }
  .test-note-card { padding: 42px; display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 70px; }
  .contact-card { padding: 46px; display: grid; grid-template-columns: 1.2fr 0.8fr; align-items: end; gap: 60px; }
  .contact-card h2 { margin-bottom: 0; }
  .contact-placeholder { padding: 0 0 0 28px; border-top: 0; border-left: 1px solid rgba(255,255,255,0.17); }
  .footer-inner { grid-template-columns: 0.7fr 1.3fr; align-items: end; }
  .footer-meta { padding: 0; border-top: 0; text-align: right; }
}

@media (min-width: 980px) {
  .site-header { position: sticky; top: 0; backdrop-filter: blur(14px); }
  .hero { min-height: calc(100vh - 78px); padding-top: 140px; display: grid; align-items: start; }
  .hero-grid { grid-template-columns: 1.3fr 0.7fr; gap: 90px; }
  .signal-card { padding: 28px; }
  .section, .platform-section, .operator-section { padding: 112px 0; }
  .contact-section { padding: 40px 0 112px; }
  .question-grid { grid-template-columns: repeat(4, 1fr); }
  .question-grid blockquote { min-height: 122px; }
  .check-grid { grid-template-columns: repeat(4, 1fr); }
  .check-grid li { min-height: 210px; padding: 25px; }
  .check-grid strong { font-size: 21px; }
}

@media (max-width: 360px) {
  .shell { width: min(100% - 28px, 1160px); }
  .hero { padding-top: 58px; }
  h1 { font-size: 44px; line-height: 1.02; }
  .signal-card, .contact-card, .test-note-card { padding: 20px; }
  .operator-facts div { grid-template-columns: 1fr; gap: 2px; }
  .operator-facts dd { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.01ms !important; }
}