:root {
  --ink: #0f1115;
  --muted: #6b7280;
  --line: #e4e7eb;
  --paper: #f5f5f7;
  --panel: #ffffff;
  --red: #111827;
  --red-dark: #000000;
  --blue: #4b5563;
  --green: #374151;
  --gold: #f5f5f7;
  --charcoal: #0f1115;
  --shadow: 0 28px 80px rgba(15, 17, 21, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "PingFang SC",
    "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img,
svg {
  display: block;
}

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 24px;
  align-items: center;
  width: 100%;
  min-height: 64px;
  padding: 10px clamp(18px, 4vw, 54px);
  color: #fff;
  background: rgba(15, 17, 21, 0.12);
  backdrop-filter: blur(18px);
  transition:
    background 180ms ease,
    box-shadow 180ms ease,
    color 180ms ease;
}

.site-header.is-scrolled {
  color: var(--ink);
  background: rgba(245, 245, 247, 0.88);
  box-shadow: 0 1px 0 rgba(15, 17, 21, 0.08);
}

.brand,
.header-cta,
.nav {
  display: flex;
  align-items: center;
}

.brand {
  gap: 10px;
  font-weight: 800;
  white-space: nowrap;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: 1px solid rgba(255, 255, 255, 0.42);
  border-radius: 8px;
  font-size: 13px;
  letter-spacing: 0;
  background: rgba(255, 255, 255, 0.08);
}

.site-header.is-scrolled .brand-mark {
  border-color: rgba(15, 17, 21, 0.18);
  background: rgba(255, 255, 255, 0.72);
}

.nav {
  justify-content: center;
  gap: clamp(14px, 3vw, 34px);
  font-size: 13px;
  font-weight: 650;
}

.nav a {
  opacity: 0.9;
}

.nav a:hover {
  opacity: 1;
}

.header-cta {
  justify-content: center;
  gap: 8px;
  min-height: 40px;
  padding: 0 15px;
  border: 1px solid rgba(255, 255, 255, 0.52);
  border-radius: 8px;
  font-weight: 700;
  background: rgba(255, 255, 255, 0.08);
}

.site-header.is-scrolled .header-cta {
  border-color: rgba(15, 17, 21, 0.12);
  background: #fff;
}

.header-cta svg,
.primary-button svg,
.secondary-button svg,
.submit-button svg,
.scroll-cue svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.hero {
  position: relative;
  min-height: 100vh;
  overflow: hidden;
  color: #fff;
  background: var(--charcoal);
}

.hero-image,
.hero-shade {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-image {
  object-fit: cover;
}

.hero-shade {
  background:
    linear-gradient(90deg, rgba(6, 8, 12, 0.9) 0%, rgba(6, 8, 12, 0.58) 42%, rgba(6, 8, 12, 0.14) 78%),
    linear-gradient(0deg, rgba(6, 8, 12, 0.52), rgba(6, 8, 12, 0.04));
}

.hero-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  width: min(820px, calc(100% - 36px));
  min-height: 100vh;
  padding: 116px 0 88px clamp(18px, 6vw, 80px);
}

.eyebrow {
  margin: 0 0 16px;
  color: #f5f5f7;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
}

.eyebrow.dark {
  color: #6e7784;
}

.hero-series {
  display: inline-grid;
  width: fit-content;
  gap: 4px;
  padding: 10px 13px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(14px);
}

.hero-series span:first-child {
  color: #fff;
  font-size: 15px;
  font-weight: 850;
}

.hero-series span:last-child {
  color: rgba(255, 255, 255, 0.72);
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.06;
}

h1 {
  max-width: 800px;
  font-size: clamp(48px, 7.8vw, 96px);
  font-weight: 860;
}

h2 {
  font-size: clamp(34px, 5vw, 64px);
  font-weight: 820;
}

h3 {
  font-size: 20px;
  font-weight: 790;
}

.hero-copy {
  max-width: 690px;
  margin: 28px 0 0;
  color: rgba(255, 255, 255, 0.82);
  font-size: clamp(18px, 2vw, 23px);
  line-height: 1.55;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 38px;
}

.primary-button,
.secondary-button,
.submit-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 52px;
  padding: 0 24px;
  border-radius: 8px;
  font-weight: 800;
}

.primary-button {
  border: 0;
  color: #0f1115;
  background: rgba(255, 255, 255, 0.92);
}

.primary-button:hover {
  background: #fff;
}

.secondary-button {
  border: 1px solid rgba(255, 255, 255, 0.38);
  color: #fff;
  background: rgba(15, 17, 21, 0.36);
  backdrop-filter: blur(10px);
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  width: min(860px, 100%);
  margin-top: 54px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(16px);
}

.hero-metrics div {
  padding: 20px 20px;
  border-right: 1px solid rgba(255, 255, 255, 0.16);
}

.hero-metrics div:last-child {
  border-right: 0;
}

.hero-metrics strong,
.hero-metrics span {
  display: block;
}

.hero-metrics strong {
  font-size: clamp(21px, 2.5vw, 30px);
  line-height: 1.2;
}

.hero-metrics span {
  margin-top: 4px;
  color: rgba(255, 255, 255, 0.76);
  font-size: 13px;
}

.scroll-cue {
  position: absolute;
  right: 36px;
  bottom: 28px;
  z-index: 2;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 8px;
  color: #fff;
}

.section-shell {
  width: min(1180px, calc(100% - 36px));
  margin: 0 auto;
}

.analysis-band,
.product-section,
.consult-section {
  padding: clamp(76px, 10vw, 136px) 0;
}

.analysis-band {
  background: #f5f5f7;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: clamp(36px, 6vw, 92px);
  align-items: start;
}

.analysis-grid,
.value-layout,
.risk-grid {
  display: grid;
  gap: 18px;
}

.analysis-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.analysis-grid article,
.feature-card,
.risk-grid article {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.analysis-grid article {
  padding: 28px;
  box-shadow: 0 1px 0 rgba(15, 17, 21, 0.03);
}

.analysis-grid span,
.timeline span {
  display: inline-grid;
  place-items: center;
  width: 36px;
  height: 36px;
  margin-bottom: 18px;
  border-radius: 8px;
  color: var(--ink);
  background: #eef0f3;
  font-weight: 800;
}

.analysis-grid p,
.feature-card p,
.risk-grid p,
.timeline p,
.section-heading p,
.product-copy > p,
.consult-copy p,
.consult-copy li,
.footer-content p {
  color: var(--muted);
}

.section-shell:not(.split):not(.product-grid):not(.consult-grid):not(.footer-content) {
  padding-top: clamp(82px, 11vw, 150px);
  padding-bottom: clamp(82px, 11vw, 150px);
}

.section-heading {
  max-width: 860px;
  margin-bottom: 50px;
}

.section-heading.compact {
  max-width: 680px;
}

.section-heading p {
  margin: 22px 0 0;
  font-size: clamp(18px, 2vw, 22px);
  line-height: 1.62;
}

.value-layout {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.feature-card {
  position: relative;
  min-height: 292px;
  padding: 34px;
  overflow: hidden;
  box-shadow: 0 1px 0 rgba(15, 17, 21, 0.03);
}

.feature-card::before {
  position: absolute;
  inset: 0 0 auto;
  height: 3px;
  content: "";
}

.accent-red::before {
  background: #111827;
}

.accent-blue::before {
  background: #6b7280;
}

.accent-green::before {
  background: #374151;
}

.icon-box {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  margin-bottom: 22px;
  border-radius: 8px;
  color: #111827;
  background: #f1f3f6;
}

.accent-blue .icon-box {
  color: #4b5563;
  background: #eef0f3;
}

.accent-green .icon-box {
  color: #374151;
  background: #e6e8eb;
}

.icon-box svg {
  width: 26px;
  height: 26px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.product-section {
  background: #fff;
}

.product-grid,
.consult-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.75fr);
  gap: clamp(34px, 6vw, 82px);
  align-items: start;
}

.spec-list {
  display: grid;
  gap: 0;
  margin-top: 42px;
  border-top: 1px solid rgba(15, 17, 21, 0.12);
}

.spec-list div {
  display: grid;
  grid-template-columns: 82px minmax(120px, 180px) 1fr;
  gap: 18px;
  align-items: start;
  padding: 24px 0;
  border-top: 1px solid rgba(23, 32, 42, 0.16);
}

.spec-list div:first-child {
  border-top: 0;
}

.spec-list span {
  color: #6e7784;
  font-size: 14px;
  font-weight: 800;
}

.spec-list strong {
  font-size: 22px;
  line-height: 1.25;
}

.spec-list p {
  margin: 0;
  color: var(--muted);
}

.simulation-panel {
  position: sticky;
  top: 96px;
  padding: 34px;
  border-radius: 8px;
  color: #fff;
  background:
    linear-gradient(145deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0)),
    var(--charcoal);
  box-shadow: 0 28px 80px rgba(15, 17, 21, 0.18);
}

.simulation-panel dl {
  display: grid;
  gap: 0;
  margin: 26px 0;
}

.simulation-panel div {
  display: grid;
  grid-template-columns: 94px 1fr;
  gap: 12px;
  padding: 15px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.18);
}

.simulation-panel dt {
  color: rgba(255, 255, 255, 0.58);
  font-weight: 800;
}

.simulation-panel dd {
  margin: 0;
  color: rgba(255, 255, 255, 0.82);
}

.simulation-panel small {
  display: block;
  margin-top: 5px;
  color: rgba(255, 255, 255, 0.58);
  font-size: 12px;
  line-height: 1.4;
}

.simulation-panel p {
  margin: 0;
  color: rgba(255, 255, 255, 0.76);
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  background: #fff;
}

.timeline article {
  min-height: 265px;
  padding: 30px;
  border-right: 1px solid var(--line);
  border-top: 0;
  background: #fff;
}

.timeline article:last-child {
  border-right: 0;
}

.proof-band {
  padding: clamp(92px, 12vw, 160px) 0;
  color: #fff;
  background:
    linear-gradient(120deg, rgba(6, 8, 12, 0.96), rgba(6, 8, 12, 0.68)),
    url("assets/hero-apartment-hidden-stair.png") center/cover fixed;
}

.proof-content {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(30px, 6vw, 74px);
  align-items: start;
}

.proof-points {
  display: grid;
  gap: 14px;
}

.proof-points div {
  padding: 26px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.22);
}

.proof-points strong {
  display: block;
  margin-bottom: 6px;
  font-size: 24px;
}

.proof-points span {
  color: rgba(255, 255, 255, 0.78);
}

.risk-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.risk-grid article {
  padding: 28px;
  min-height: 230px;
}

.consult-section {
  color: #fff;
  background:
    radial-gradient(circle at 82% 18%, rgba(255, 255, 255, 0.11), transparent 34%),
    #090b0f;
}

.consult-copy p,
.consult-copy li {
  color: rgba(255, 255, 255, 0.78);
}

.consult-copy ul {
  display: grid;
  gap: 10px;
  margin: 28px 0 0;
  padding-left: 20px;
}

.lead-form {
  display: grid;
  gap: 16px;
  padding: 30px;
  border-radius: 8px;
  color: var(--ink);
  background: #fff;
  box-shadow: 0 28px 80px rgba(0, 0, 0, 0.24);
}

.form-trap {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.lead-form label {
  display: grid;
  gap: 7px;
  color: var(--ink);
  font-size: 14px;
  font-weight: 800;
}

input,
select,
textarea {
  width: 100%;
  min-height: 46px;
  padding: 12px 13px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  font: inherit;
  background: #fff;
}

textarea {
  resize: vertical;
}

input:focus,
select:focus,
textarea:focus {
  outline: 3px solid rgba(15, 17, 21, 0.12);
  border-color: #111827;
}

.submit-button {
  width: 100%;
  cursor: pointer;
  font: inherit;
  border: 0;
  color: #fff;
  background: var(--ink);
}

.submit-button:hover {
  background: #000;
}

.form-note {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.form-note.is-success {
  color: #374151;
  font-weight: 800;
}

.site-footer {
  padding: 28px 0;
  background: #050609;
  color: #fff;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  gap: 28px;
  align-items: center;
}

.footer-content p {
  max-width: 620px;
  margin: 4px 0 0;
  color: rgba(255, 255, 255, 0.66);
  font-size: 13px;
}

@media (max-width: 980px) {
  .site-header {
    grid-template-columns: 1fr auto;
  }

  .nav {
    display: none;
  }

  .split,
  .product-grid,
  .proof-content,
  .consult-grid {
    grid-template-columns: 1fr;
  }

  .analysis-grid,
  .value-layout,
  .timeline,
  .risk-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .simulation-panel {
    position: static;
  }
}

@media (max-width: 680px) {
  .site-header {
    min-height: 62px;
    padding: 10px 14px;
  }

  .brand span:last-child {
    display: none;
  }

  .header-cta {
    min-height: 40px;
    padding: 0 12px;
    font-size: 14px;
  }

  .hero,
  .hero-content {
    min-height: 100svh;
  }

  .hero-shade {
    background:
      linear-gradient(0deg, rgba(8, 10, 14, 0.94) 0%, rgba(8, 10, 14, 0.72) 46%, rgba(8, 10, 14, 0.22) 100%),
      linear-gradient(90deg, rgba(8, 10, 14, 0.76), rgba(8, 10, 14, 0.1));
  }

  .hero-content {
    justify-content: center;
    width: 100%;
    padding: 86px 18px 44px;
  }

  h1 {
    font-size: 40px;
    line-height: 1.08;
  }

  h2 {
    font-size: 31px;
    line-height: 1.16;
  }

  h3 {
    font-size: 18px;
  }

  .hero-copy {
    margin-top: 20px;
    font-size: 16px;
    line-height: 1.62;
  }

  .hero-series {
    max-width: 100%;
    padding: 9px 11px;
  }

  .hero-series span:first-child {
    font-size: 13px;
  }

  .hero-series span:last-child {
    font-size: 12px;
  }

  .hero-actions {
    margin-top: 24px;
  }

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

  .hero-metrics {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    margin-top: 24px;
  }

  .hero-metrics div {
    min-height: 78px;
    padding: 14px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.18);
    border-right: 0;
  }

  .hero-metrics div:nth-child(odd) {
    border-right: 1px solid rgba(255, 255, 255, 0.16);
  }

  .hero-metrics strong {
    font-size: 22px;
  }

  .hero-metrics span {
    font-size: 12px;
  }

  .analysis-grid,
  .value-layout,
  .timeline,
  .risk-grid {
    grid-template-columns: 1fr;
  }

  .spec-list div {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .simulation-panel div {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .section-shell {
    width: min(100% - 28px, 1180px);
  }

  .analysis-band,
  .product-section,
  .consult-section {
    padding: 58px 0;
  }

  .section-shell:not(.split):not(.product-grid):not(.consult-grid):not(.footer-content) {
    padding-top: 58px;
    padding-bottom: 58px;
  }

  .section-heading {
    margin-bottom: 30px;
  }

  .section-heading p,
  .product-copy > p,
  .consult-copy p {
    font-size: 16px;
  }

  .feature-card,
  .analysis-grid article,
  .risk-grid article,
  .timeline article,
  .lead-form,
  .simulation-panel {
    padding: 22px;
  }

  .feature-card,
  .timeline article,
  .risk-grid article {
    min-height: auto;
  }

  .timeline {
    border: 0;
    background: transparent;
    gap: 14px;
  }

  .timeline article {
    border: 1px solid var(--line);
    border-radius: 8px;
  }

  .proof-band {
    background-attachment: scroll;
  }

  .lead-form {
    gap: 14px;
  }

  input,
  select,
  textarea {
    min-height: 50px;
    font-size: 16px;
  }

  .scroll-cue {
    display: none;
  }

  .footer-content {
    display: grid;
  }
}

@media (max-width: 390px) {
  .site-header {
    padding: 9px 12px;
  }

  .header-cta {
    padding: 0 10px;
    font-size: 13px;
  }

  .hero-content {
    padding: 78px 14px 34px;
  }

  h1 {
    font-size: 35px;
  }

  .hero-copy {
    font-size: 15px;
  }

  .hero-metrics {
    grid-template-columns: 1fr;
  }

  .hero-metrics div:nth-child(odd) {
    border-right: 0;
  }

  .hero-metrics div {
    min-height: auto;
    padding: 12px 14px;
  }
}

@media print {
  @page {
    size: A4;
    margin: 0;
  }

  * {
    print-color-adjust: exact;
    -webkit-print-color-adjust: exact;
  }

  body {
    background: #fff;
  }

  .site-header {
    position: absolute;
  }

  .scroll-cue {
    display: none;
  }

  .hero {
    min-height: 100vh;
    break-after: page;
  }

  .hero-content {
    min-height: 100vh;
  }

  .analysis-grid article,
  .feature-card,
  .timeline article,
  .risk-grid article,
  .simulation-panel,
  .lead-form {
    break-inside: avoid;
  }

  .proof-band {
    background:
      linear-gradient(120deg, rgba(6, 8, 12, 0.96), rgba(6, 8, 12, 0.68)),
      url("assets/hero-apartment-hidden-stair.png") center/cover;
  }
}