:root {
  --bg: #F7F4EF;
  --surface: #FFFFFF;
  --ink: #1C1B1A;
  --muted: #5D5A52;
  --line: #E6E1D6;
  --accent: #2056C9;
  --accent-deep: #143A8C;
  --accent-tint: #E6EEFA;
  --dark: #141414;
  --dark-ink: #F2EFE9;
  --dark-muted: #9B968C;
  --sidebar-w: 264px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-size: 16px;
  font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.65;
  background: var(--bg);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
}

body.home-page {
  overflow-x: hidden;
}

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

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

/* ---------- Sidebar navigation ---------- */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  background: var(--dark);
  color: var(--dark-ink);
  display: flex;
  flex-direction: column;
  z-index: 50;
  border-right: 1px solid #242424;
}

.site-nav-inner {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 40px 28px 32px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: #fff;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  letter-spacing: 0.5px;
  border-radius: 10px;
  font-size: 15px;
}

.brand-text {
  font-weight: 700;
  line-height: 1.2;
  font-size: 17px;
  color: #fff;
}

.nav-links {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-top: 44px;
}

.nav-link {
  display: block;
  padding: 11px 14px;
  border-radius: 10px;
  color: var(--dark-muted);
  font-size: 15px;
  font-weight: 500;
  transition: background 0.2s ease, color 0.2s ease;
}

.nav-link:hover {
  color: #fff;
  background: #262626;
}

.nav-link.active {
  color: #fff;
  background: #1E3E7A;
}

.nav-contact {
  margin-top: auto;
  padding-top: 24px;
  border-top: 1px solid #2a2a2a;
}

.nav-contact-label {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--dark-muted);
  margin-bottom: 10px;
}

.nav-contact-link {
  display: block;
  color: #fff;
  font-size: 14px;
  margin-bottom: 4px;
}

.nav-cta {
  display: inline-block;
  margin-top: 14px;
  padding: 11px 16px;
  background: var(--accent);
  color: #fff;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 600;
  text-align: center;
}

.nav-cta:hover {
  background: var(--accent-deep);
}

/* Mobile toggle */
.nav-toggle {
  display: none;
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 60;
  width: 46px;
  height: 46px;
  background: var(--dark);
  border: none;
  border-radius: 10px;
  cursor: pointer;
  padding: 11px 10px;
  flex-direction: column;
  justify-content: space-between;
}

.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: #fff;
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.nav-toggle.open span:nth-child(1) {
  transform: translateY(9px) rotate(45deg);
}
.nav-toggle.open span:nth-child(2) {
  opacity: 0;
}
.nav-toggle.open span:nth-child(3) {
  transform: translateY(-9px) rotate(-45deg);
}

/* ---------- Main content ---------- */
.home-main {
  margin-left: var(--sidebar-w);
  min-height: 100vh;
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 40px;
}

/* ---------- Reveal animation ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 14px 26px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 15px;
  border: none;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-deep);
  transform: translateY(-2px);
}

.btn-ghost {
  background: transparent;
  color: var(--ink);
  border: 1.5px solid var(--line);
}

.btn-ghost:hover {
  border-color: var(--ink);
}

.btn-block {
  width: 100%;
}

/* ---------- Section scaffolding ---------- */
.kicker {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--accent);
  font-weight: 700;
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.15;
  letter-spacing: -0.5px;
  margin-bottom: 16px;
}

.section-lede {
  color: var(--muted);
  font-size: 17px;
  max-width: 640px;
}

.section-head {
  margin-bottom: 48px;
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  background:
    radial-gradient(900px 460px at 85% -10%, var(--accent-tint) 0%, transparent 60%),
    radial-gradient(700px 420px at -10% 110%, #EDE6F9 0%, transparent 55%),
    var(--bg);
  padding: 96px 0 60px;
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(230, 225, 214, 0.35) 1px, transparent 1px), linear-gradient(90deg, rgba(230, 225, 214, 0.35) 1px, transparent 1px);
  background-size: 46px 46px;
  pointer-events: none;
}

.hero-container {
  position: relative;
  z-index: 1;
}

.eyebrow {
  font-size: 13px;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 700;
  margin-bottom: 22px;
}

.hero-title {
  font-size: clamp(34px, 6vw, 60px);
  line-height: 1.05;
  letter-spacing: -1.5px;
  margin-bottom: 26px;
}

.hero-lede {
  font-size: 18px;
  color: var(--muted);
  max-width: 640px;
  margin-bottom: 32px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

/* Floating stat cluster */
.stat-cluster {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
}

.stat-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 22px 26px;
  min-width: 150px;
  box-shadow: 0 18px 40px rgba(28, 27, 26, 0.08);
  text-align: center;
}

.stat-card:nth-child(1) { transform: translateY(10px); }
.stat-card:nth-child(2) { transform: translateY(-6px); }
.stat-card:nth-child(3) { transform: translateY(14px); }
.stat-card:nth-child(4) { transform: translateY(0); }

.stat-number {
  font-size: 40px;
  font-weight: 800;
  line-height: 1;
  color: var(--accent);
  display: inline-block;
}

.stat-suffix {
  font-size: 24px;
  font-weight: 700;
  color: var(--accent);
}

.stat-label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  color: var(--muted);
}

/* ---------- About ---------- */
.about-section {
  background: var(--surface);
  padding: 96px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.about-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.9fr;
  gap: 56px;
  align-items: start;
}

.about-text p {
  color: var(--muted);
  font-size: 17px;
  margin-bottom: 18px;
}

.about-text p:first-child {
  color: var(--ink);
  font-size: 19px;
}

.about-facts {
  display: flex;
  flex-direction: column;
  gap: 22px;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 28px;
}

.fact {
  display: flex;
  gap: 18px;
  align-items: flex-start;
}

.fact-num {
  font-size: 15px;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: 1px;
}

.fact h3 {
  font-size: 17px;
  margin-bottom: 4px;
}

.fact p {
  color: var(--muted);
  font-size: 14.5px;
}

/* ---------- Services ---------- */
.services-section {
  background: var(--bg);
  padding: 96px 0;
}

.service-list {
  list-style: none;
  display: flex;
  flex-direction: column;
}

.service-item {
  display: flex;
  gap: 30px;
  padding: 34px 0;
  border-top: 1px solid var(--line);
  align-items: flex-start;
}

.service-item:last-child {
  border-bottom: 1px solid var(--line);
}

.service-index {
  font-size: 18px;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: 1px;
  padding-top: 4px;
  flex-shrink: 0;
}

.service-body h3 {
  font-size: 22px;
  margin-bottom: 8px;
}

.service-body p {
  color: var(--muted);
  max-width: 720px;
}

/* ---------- Comparison table ---------- */
.comparison-section {
  background: var(--surface);
  padding: 96px 0;
  border-top: 1px solid var(--line);
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 16px;
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
  min-width: 620px;
}

.compare-table thead th {
  background: var(--dark);
  color: #fff;
  text-align: left;
  padding: 18px 20px;
  font-weight: 600;
}

.compare-table thead th.col-dengxi {
  background: var(--accent);
}

.compare-table tbody th,
.compare-table tbody td {
  padding: 16px 20px;
  text-align: left;
  border-top: 1px solid var(--line);
  vertical-align: top;
}

.compare-table tbody th {
  font-weight: 700;
  color: var(--ink);
  white-space: nowrap;
}

.compare-table tbody td {
  color: var(--muted);
}

.compare-table tbody td.col-dengxi {
  color: var(--ink);
  background: var(--accent-tint);
  font-weight: 500;
}

/* ---------- Process timeline ---------- */
.process-section {
  background: var(--bg);
  padding: 96px 0;
}

.timeline {
  list-style: none;
  position: relative;
  padding-left: 34px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--line);
}

.timeline-item {
  position: relative;
  padding-bottom: 30px;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: -34px;
  top: 6px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 4px solid var(--bg);
  box-shadow: 0 0 0 2px var(--accent);
}

.timeline-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 22px 26px;
}

.timeline-step {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--accent);
  font-weight: 700;
}

.timeline-card h3 {
  font-size: 20px;
  margin: 6px 0 6px;
}

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

/* ---------- Engagement models ---------- */
.models-section {
  background: var(--surface);
  padding: 96px 0;
  border-top: 1px solid var(--line);
}

.models-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.model-card {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 30px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.model-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px rgba(28, 27, 26, 0.08);
}

.model-tag {
  display: inline-block;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--accent);
  font-weight: 700;
  border: 1px solid var(--accent);
  padding: 3px 10px;
  border-radius: 20px;
  margin-bottom: 16px;
}

.model-card h3 {
  font-size: 21px;
  margin-bottom: 10px;
}

.model-card p {
  color: var(--muted);
}

/* ---------- FAQ ---------- */
.faq-section {
  background: var(--bg);
  padding: 96px 0;
}

.faq-container {
  max-width: 800px;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  overflow: hidden;
}

.faq-question {
  width: 100%;
  text-align: left;
  background: transparent;
  border: none;
  padding: 20px 24px;
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.faq-question::after {
  content: "+";
  font-size: 22px;
  color: var(--accent);
  font-weight: 400;
  transition: transform 0.25s ease;
}

.faq-item.active .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease;
}

.faq-answer p {
  padding: 0 24px 20px;
  color: var(--muted);
}

.faq-item.active .faq-answer {
  max-height: 400px;
}

/* ---------- Contact ---------- */
.contact-section {
  background: var(--surface);
  padding: 96px 0;
  border-top: 1px solid var(--line);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
}

.contact-intro p {
  color: var(--muted);
  margin-bottom: 28px;
}

.contact-meta {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.contact-meta-item {
  display: flex;
  flex-direction: column;
}

.contact-meta-label {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--muted);
  margin-bottom: 2px;
}

.contact-meta-item a,
.contact-meta-item span {
  font-weight: 600;
  color: var(--ink);
}

.contact-form {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 32px;
}

.field {
  margin-bottom: 18px;
}

.field label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--ink);
}

.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  color: var(--ink);
  font-size: 15px;
  font-family: inherit;
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: 2px solid var(--accent);
  outline-offset: 0;
}

.form-note {
  margin-top: 14px;
  font-size: 14px;
  color: var(--accent-deep);
  font-weight: 600;
}

/* ---------- Footer ---------- */
.footer {
  background: var(--dark);
  color: var(--dark-ink);
}

.newsletter-band {
  background: var(--accent);
  padding: 40px 0;
}

.newsletter-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.newsletter-text {
  color: #fff;
  font-size: 17px;
  font-weight: 600;
  max-width: 420px;
}

.newsletter-form {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.newsletter-form input {
  padding: 13px 16px;
  border-radius: 10px;
  border: none;
  font-size: 15px;
  min-width: 240px;
  font-family: inherit;
}

.newsletter-form input:focus {
  outline: 2px solid #fff;
}

.footer-main {
  position: relative;
  overflow: hidden;
  padding: 64px 0 40px;
}

.footer-columns {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col h4 {
  color: #fff;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 8px;
}

.footer-col a,
.footer-col span {
  color: var(--dark-muted);
  font-size: 15px;
}

.footer-col a:hover {
  color: #fff;
}

.brand-light .brand-text {
  color: #fff;
}

.footer-tagline {
  color: var(--dark-muted);
  font-size: 14px;
  margin-top: 14px;
  max-width: 260px;
}

.footer-watermark {
  position: absolute;
  right: -20px;
  bottom: -30px;
  font-size: clamp(120px, 18vw, 240px);
  font-weight: 800;
  line-height: 1;
  color: #1E1E1E;
  pointer-events: none;
  user-select: none;
  letter-spacing: -4px;
  visibility: hidden;
}

.footer-bottom {
  border-top: 1px solid #2a2a2a;
  padding: 20px 0;
}

.footer-bottom-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.footer-bottom p {
  color: var(--dark-muted);
  font-size: 13px;
}

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .about-grid,
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .models-grid {
    grid-template-columns: 1fr;
  }

  .footer-columns {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 760px) {
  .site-nav {
    transform: translateX(-100%);
    transition: transform 0.3s ease;
  }

  .site-nav.open {
    transform: translateX(0);
  }

  .nav-toggle {
    display: flex;
  }

  .home-main {
    margin-left: 0;
  }

  .container {
    padding: 0 22px;
  }

  .hero {
    padding: 84px 0 48px;
  }

  .stat-cluster {
    gap: 14px;
  }

  .stat-card {
    min-width: 130px;
    padding: 16px 18px;
  }

  .service-item {
    flex-direction: column;
    gap: 12px;
  }

  .section-head {
    margin-bottom: 34px;
  }

  .about-section,
  .services-section,
  .comparison-section,
  .process-section,
  .models-section,
  .faq-section,
  .contact-section {
    padding: 64px 0;
  }

  .footer-columns {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .footer-watermark {
    font-size: 100px;
  }
}