:root {
  color-scheme: light;
  --ink: #14181d;
  --muted: #5c6670;
  --paper: #f6f7f9;
  --surface: #ffffff;
  --line: #d9dde2;
  --navy: #183449;
  --teal: #2f6f65;
  --brick: #913746;
  --gold: #bd781f;
  --shadow: 0 18px 55px rgba(18, 24, 29, 0.16);
  --max: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.7;
}

a {
  color: inherit;
  text-decoration: none;
}

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(18px, 4vw, 48px);
  color: #fff;
  transition: background 180ms ease, box-shadow 180ms ease, padding 180ms ease;
}

.site-header.is-scrolled {
  padding-top: 10px;
  padding-bottom: 10px;
  background: rgba(20, 24, 29, 0.92);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 260px;
}

.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.42);
  background: rgba(255, 255, 255, 0.11);
  font-weight: 800;
  letter-spacing: 0;
  flex: 0 0 auto;
}

.brand-copy,
.brand-title,
.brand-phone {
  display: block;
}

.brand-copy {
  min-width: 0;
}

.brand-title {
  font-size: 15px;
  font-weight: 800;
  line-height: 1.2;
  white-space: nowrap;
}

.brand-phone {
  width: fit-content;
  margin-top: 4px;
  color: rgba(255, 255, 255, 0.76);
  font-size: 12px;
  font-weight: 800;
  line-height: 1.2;
  white-space: nowrap;
}

.brand-phone:hover {
  color: #fff;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.site-nav a {
  padding: 8px 12px;
  color: rgba(255, 255, 255, 0.86);
  font-size: 14px;
  border: 1px solid transparent;
}

.site-nav a:hover,
.site-nav a.is-active {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.28);
  background: rgba(255, 255, 255, 0.1);
}

.nav-toggle {
  display: none;
  width: 46px;
  height: 42px;
  border: 1px solid rgba(255, 255, 255, 0.38);
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 4px auto;
  background: currentColor;
}

.nav-toggle b {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
}

.hero {
  position: relative;
  min-height: 74vh;
  display: grid;
  align-items: end;
  overflow: hidden;
  color: #fff;
  background: #142635;
}

.hero-media,
.hero-overlay {
  position: absolute;
  inset: 0;
}

.hero-media {
  background-image: url("./hero-changsha-investigation.png");
  background-size: cover;
  background-position: center;
  transform: scale(1.02);
}

.hero-overlay {
  background:
    linear-gradient(90deg, rgba(10, 15, 20, 0.88) 0%, rgba(10, 15, 20, 0.72) 42%, rgba(10, 15, 20, 0.2) 100%),
    linear-gradient(0deg, rgba(10, 15, 20, 0.62) 0%, rgba(10, 15, 20, 0.05) 52%);
}

.hero-inner {
  position: relative;
  z-index: 1;
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
  padding: 144px 0 48px;
}

.eyebrow,
.section-label {
  margin: 0 0 14px;
  color: var(--gold);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero h1 {
  width: min(850px, 100%);
  margin: 0;
  font-size: clamp(38px, 6vw, 76px);
  line-height: 1.04;
  letter-spacing: 0;
}

.hero-copy {
  width: min(720px, 100%);
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.86);
  font-size: clamp(16px, 2vw, 19px);
}

.hero-actions,
.keyword-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-actions {
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 18px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  color: var(--ink);
  font-weight: 700;
  cursor: pointer;
}

.button.primary {
  border-color: var(--gold);
  background: var(--gold);
  color: #15100a;
}

.button.secondary {
  border-color: rgba(255, 255, 255, 0.36);
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
}

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

.floating-contact {
  position: fixed;
  top: 50%;
  right: clamp(12px, 2vw, 28px);
  z-index: 40;
  display: grid;
  gap: 10px;
  justify-items: end;
  transform: translateY(-50%);
  pointer-events: none;
}

.floating-contact-button,
.floating-contact-value {
  pointer-events: auto;
}

.floating-contact-button {
  width: 78px;
  min-height: 78px;
  display: grid;
  place-items: center;
  gap: 5px;
  padding: 9px 8px;
  border: 1px solid rgba(255, 255, 255, 0.26);
  border-radius: 8px;
  background: rgba(17, 23, 29, 0.92);
  color: #fff;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.24);
  font: inherit;
  font-size: 14px;
  font-weight: 800;
  cursor: pointer;
  backdrop-filter: blur(14px);
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.floating-contact-button:hover,
.floating-contact-button.is-active {
  transform: translateX(-3px);
  border-color: rgba(255, 255, 255, 0.58);
}

.floating-contact-button.phone.is-active {
  background: rgba(189, 120, 31, 0.94);
}

.floating-contact-button.wechat.is-active {
  background: rgba(21, 150, 86, 0.96);
}

.floating-icon {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
}

.floating-icon svg {
  width: 100%;
  height: 100%;
  display: block;
}

.floating-contact-button.phone .floating-icon svg {
  fill: none;
  stroke: #f1c579;
  stroke-width: 2.2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.floating-contact-button.phone .floating-icon circle {
  fill: #f1c579;
  stroke: none;
}

.wechat-bg {
  fill: #1aad19;
}

.wechat-bubble-main,
.wechat-bubble-small {
  fill: #fff;
}

.wechat-dot,
.wechat-dot-green {
  fill: #1aad19;
}

.floating-contact-value {
  position: absolute;
  top: 50%;
  right: calc(100% + 12px);
  min-width: 220px;
  padding: 12px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  background: rgba(17, 23, 29, 0.95);
  color: #fff;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.22);
  transform: translateY(-50%);
  backdrop-filter: blur(14px);
}

.floating-contact-value[hidden] {
  display: none;
}

.contact-label,
.contact-text,
.contact-copy-status {
  display: block;
}

.contact-label {
  color: rgba(255, 255, 255, 0.68);
  font-size: 12px;
}

.contact-text {
  margin-top: 2px;
  color: #fff;
  font-size: 17px;
  user-select: text;
}

.contact-copy {
  width: 100%;
  min-height: 36px;
  margin-top: 10px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 6px;
  background: var(--gold);
  color: #15100a;
  font: inherit;
  font-weight: 900;
  cursor: pointer;
}

.contact-copy-status {
  min-height: 20px;
  margin-top: 6px;
  color: #9be1be;
  font-size: 12px;
  text-align: center;
}

.keyword-tabs {
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
}

.keyword-tabs li {
  padding: 8px 12px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  background: rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.86);
  font-size: 13px;
}

.section {
  width: min(var(--max), calc(100% - 36px));
  margin: 0 auto;
  padding: 84px 0;
  scroll-margin-top: 86px;
}

.band {
  width: 100%;
  padding-left: max(18px, calc((100% - var(--max)) / 2));
  padding-right: max(18px, calc((100% - var(--max)) / 2));
  background: #eef2f5;
}

.section-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 410px);
  gap: clamp(28px, 6vw, 72px);
  align-items: start;
}

.section-heading {
  width: min(760px, 100%);
  margin-bottom: 34px;
}

h2,
h3,
p {
  margin-top: 0;
}

h2 {
  margin-bottom: 16px;
  font-size: clamp(28px, 4vw, 48px);
  line-height: 1.12;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 12px;
  font-size: 21px;
  line-height: 1.25;
}

.lead {
  color: #2f3840;
  font-size: clamp(18px, 2.2vw, 23px);
  line-height: 1.55;
}

.intro-section {
  padding-top: 72px;
}

.answer-box,
.checklist-panel,
.boundary-panel,
.service-card,
.faq-list details {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 8px;
}

.answer-box {
  padding: 28px;
  box-shadow: var(--shadow);
  border-top: 5px solid var(--teal);
}

.answer-box h3,
.checklist-panel h3 {
  color: var(--navy);
}

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

.service-card {
  min-height: 242px;
  padding: 24px;
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.service-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 36px rgba(24, 52, 73, 0.13);
}

.card-index {
  display: inline-block;
  margin-bottom: 26px;
  color: var(--brick);
  font-weight: 900;
}

.boundary-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.boundary-panel {
  padding: 30px;
}

.boundary-panel h3 {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.boundary-panel h3::before {
  content: "";
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--teal);
}

.boundary-panel.denied h3::before {
  background: var(--brick);
}

.boundary-panel ul,
.checklist-panel ul {
  margin: 0;
  padding-left: 20px;
}

.boundary-panel li,
.checklist-panel li {
  margin: 9px 0;
}

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

.timeline li {
  position: relative;
  min-height: 210px;
  padding: 24px 20px;
  border-top: 4px solid var(--navy);
  background: var(--surface);
  box-shadow: 0 10px 28px rgba(20, 24, 29, 0.08);
}

.timeline li::before {
  counter-increment: steps;
  content: "0" counter(steps);
  display: block;
  margin-bottom: 36px;
  color: var(--gold);
  font-size: 13px;
  font-weight: 900;
}

.timeline strong,
.timeline span {
  display: block;
}

.timeline strong {
  margin-bottom: 10px;
  font-size: 20px;
}

.timeline span {
  color: var(--muted);
}

.geo-section {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.code-readable-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  clip-path: inset(50%);
  border: 0;
  white-space: normal;
}

.geo-facts {
  margin-top: 30px;
}

.geo-facts dl {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 0;
}

.geo-facts div {
  padding: 18px;
  background: #edf4f2;
  border-left: 4px solid var(--teal);
}

.geo-facts dt {
  margin-bottom: 8px;
  color: var(--navy);
  font-weight: 800;
}

.geo-facts dd {
  margin: 0;
  color: var(--muted);
}

.checklist-panel {
  padding: 28px;
  border-top: 5px solid var(--gold);
}

.copy-button {
  width: 100%;
  margin-top: 18px;
  border-color: var(--navy);
  background: var(--navy);
  color: #fff;
}

.copy-status {
  min-height: 26px;
  margin: 10px 0 0;
  color: var(--teal);
  font-size: 14px;
}

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

.faq-list details {
  padding: 0 22px;
}

.faq-list summary {
  min-height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  font-weight: 800;
  cursor: pointer;
}

.faq-list summary::after {
  content: "+";
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  border: 1px solid var(--line);
  color: var(--navy);
}

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

.faq-list details p {
  padding-bottom: 22px;
  color: var(--muted);
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 36px max(18px, calc((100% - var(--max)) / 2));
  background: #11171d;
  color: rgba(255, 255, 255, 0.82);
}

.site-footer p {
  margin: 4px 0 0;
  color: rgba(255, 255, 255, 0.62);
}

.site-footer a {
  color: #fff;
  font-weight: 800;
}

@media (max-width: 940px) {
  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 8px);
    left: 18px;
    right: 18px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 10px;
    background: rgba(20, 24, 29, 0.96);
    border: 1px solid rgba(255, 255, 255, 0.16);
  }

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

  .site-nav a {
    padding: 12px;
  }

  .section-grid,
  .boundary-grid,
  .timeline {
    grid-template-columns: 1fr;
  }

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

  .timeline li {
    min-height: auto;
  }

  .timeline li::before {
    margin-bottom: 18px;
  }
}

@media (max-width: 640px) {
  .site-header {
    padding-left: 16px;
    padding-right: 16px;
  }

  .brand {
    min-width: 0;
    flex: 1 1 auto;
    gap: 10px;
  }

  .brand-title {
    font-size: 13px;
  }

  .brand-phone {
    margin-top: 3px;
    font-size: 12px;
  }

  .hero {
    min-height: 82vh;
  }

  .hero-inner {
    width: calc(100% - 32px);
    padding-top: 112px;
    padding-bottom: 32px;
  }

  .hero h1 {
    font-size: 40px;
  }

  .hero-actions .button {
    width: 100%;
  }

  .floating-contact {
    right: 10px;
  }

  .floating-contact-button {
    width: 64px;
    min-height: 66px;
    font-size: 13px;
  }

  .floating-icon {
    width: 28px;
    height: 28px;
  }

  .floating-contact-value {
    min-width: 166px;
    max-width: calc(100vw - 92px);
    padding: 9px 12px;
  }

  .keyword-tabs {
    gap: 8px;
  }

  .keyword-tabs li {
    flex: 1 1 100%;
    text-align: center;
  }

  .section {
    width: calc(100% - 32px);
    padding: 58px 0;
  }

  .band {
    width: 100%;
    padding-left: 16px;
    padding-right: 16px;
  }

  .service-grid,
  .geo-facts dl {
    grid-template-columns: 1fr;
  }

  .service-card {
    min-height: auto;
  }

  .site-footer {
    display: block;
  }

  .site-footer a {
    display: inline-block;
    margin-top: 18px;
  }
}