:root {
  --bg: #ffffff;
  --ink: #1b1f23;
  --muted: #5f6975;
  --faint: #eef4f6;
  --line: #d7e1e4;
  --line-strong: #aebfc5;
  --graphite: #1b1f23;
  --teal: #3a8798;
  --teal-dark: #2c6f7c;
  --copper: var(--teal);
  --copper-dark: var(--teal-dark);
  --steel: #3a8798;
  --steel-soft: #eef6f8;
  --panel: rgba(255, 255, 255, 0.86);
  --shadow: 0 24px 70px rgba(18, 35, 42, 0.12);
  --max: 1180px;
  --header-h: 76px;
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.5;
  letter-spacing: 0;
}

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

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

button,
input,
textarea {
  font: inherit;
}

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 0 max(28px, calc((100vw - var(--max)) / 2));
  border-bottom: 1px solid rgba(216, 222, 229, 0.86);
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(16px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 248px;
}

.brand-logo {
  width: 156px;
  height: auto;
}

.brand-tagline {
  border-left: 1px solid var(--line-strong);
  padding-left: 12px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  line-height: 1.2;
  white-space: nowrap;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 28px;
  color: #202832;
  font-size: 14px;
  white-space: nowrap;
}

.nav a {
  position: relative;
  padding: 28px 0;
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 20px;
  height: 2px;
  background: var(--copper);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 180ms ease;
}

.nav a:hover::after,
.nav a.is-active::after {
  transform: scaleX(1);
}

.header-cta,
.lang-toggle,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: 2px;
  font-size: 14px;
  font-weight: 700;
  white-space: nowrap;
  transition: transform 180ms ease, background 180ms ease, border-color 180ms ease;
}

.lang-toggle {
  min-width: 48px;
  padding: 0 14px;
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, 0.72);
  color: var(--steel);
  cursor: pointer;
}

.lang-toggle:hover {
  border-color: var(--steel);
  transform: translateY(-1px);
}

.header-cta,
.button.primary {
  background: var(--copper);
  color: #fff;
}

.header-cta:hover,
.button.primary:hover {
  background: var(--copper-dark);
  transform: translateY(-1px);
}

.button.secondary {
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, 0.7);
  color: var(--ink);
}

.button.secondary:hover {
  border-color: var(--steel);
  transform: translateY(-1px);
}

.menu-button {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 2px;
  color: var(--ink);
}

.menu-button span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 5px auto;
  background: currentColor;
}

.hero {
  min-height: 720px;
  padding-top: var(--header-h);
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
}

.hero-media {
  position: absolute;
  inset: var(--header-h) 0 0 0;
  background: #f5f7f9;
}

.hero-media::before {
  content: "";
  position: absolute;
  z-index: 1;
  inset: 0;
  background: linear-gradient(90deg, #fff 0%, rgba(255, 255, 255, 0.96) 25%, rgba(255, 255, 255, 0.52) 48%, rgba(255, 255, 255, 0.12) 72%);
}

.hero-media::after {
  content: "";
  position: absolute;
  z-index: 1;
  inset: auto 0 0 0;
  height: 190px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0), #fff 90%);
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center right;
}

.hero-inner {
  position: relative;
  z-index: 2;
  width: min(var(--max), calc(100% - 56px));
  min-height: calc(720px - var(--header-h));
  margin: 0 auto;
  display: flex;
  align-items: center;
}

.hero-copy {
  width: min(560px, 100%);
  padding: 70px 0 58px;
}

html[lang="en"] .hero-copy {
  width: min(640px, 100%);
}

.section-index {
  margin: 0 0 20px;
  color: var(--copper);
  font-size: 13px;
  font-weight: 700;
  line-height: 1.2;
}

.hero h1,
.section h2 {
  margin: 0;
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: 0;
}

.hero h1 {
  max-width: 480px;
  font-size: 64px;
}

html[lang="en"] .hero h1 {
  max-width: 620px;
  font-size: 58px;
  line-height: 1.06;
}

.hero-lead {
  max-width: 520px;
  margin: 26px 0 0;
  color: #25313d;
  font-size: 19px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.hero-proof {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  max-width: 520px;
  margin: 48px 0 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.hero-proof div {
  padding: 18px 18px 18px 0;
  border-right: 1px solid var(--line);
}

.hero-proof div:last-child {
  border-right: 0;
  padding-right: 0;
  padding-left: 18px;
}

.hero-proof div:nth-child(2) {
  padding-left: 18px;
}

.hero-proof dt {
  color: var(--copper);
  font-size: 12px;
  font-weight: 700;
}

.hero-proof dd {
  margin: 6px 0 0;
  color: var(--ink);
  font-size: 15px;
  font-weight: 700;
}

.section {
  width: min(var(--max), calc(100% - 56px));
  margin: 0 auto;
  padding: 92px 0;
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(260px, 0.9fr) minmax(320px, 1.15fr);
  gap: 76px;
  align-items: end;
  margin-bottom: 40px;
}

.section-heading.compact {
  display: block;
  max-width: 580px;
  margin-bottom: 34px;
}

.section-heading h2,
.position-band h2 {
  font-size: 36px;
}

.section-heading p:not(.section-index),
.position-band > p,
.contact-copy p,
.contact-copy li {
  margin: 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.85;
}

.product-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.product-card {
  min-height: 220px;
  padding: 30px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: #fff;
}

.product-card.featured {
  background: linear-gradient(180deg, #fff, #f4fafb);
}

.product-card h3,
.workflow h3,
.scenario-list h3,
.package-flow h3 {
  margin: 18px 0 10px;
  color: var(--ink);
  font-size: 19px;
  line-height: 1.25;
}

.product-card p,
.workflow p,
.scenario-list p,
.package-flow p,
.form-note {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.line-icon {
  display: block;
  width: 54px;
  height: 54px;
  color: var(--copper);
  position: relative;
}

.line-icon::before,
.line-icon::after {
  content: "";
  position: absolute;
  border: 2px solid currentColor;
}

.flex-icon::before {
  width: 46px;
  height: 18px;
  left: 2px;
  top: 18px;
  border-left: 0;
  border-right: 0;
  border-radius: 50%;
  transform: rotate(-12deg);
}

.flex-icon::after {
  width: 44px;
  height: 32px;
  left: 6px;
  top: 10px;
  border-left: 0;
  border-right: 0;
  border-radius: 50%;
  transform: rotate(-12deg);
}

.braid-icon::before {
  width: 38px;
  height: 28px;
  left: 8px;
  top: 12px;
  border-radius: 999px;
  transform: skewX(-18deg);
}

.braid-icon::after {
  width: 38px;
  height: 0;
  left: 8px;
  top: 26px;
  border-left: 0;
  border-right: 0;
  border-bottom: 0;
  transform: skewX(-18deg);
}

.insulation-icon::before {
  width: 30px;
  height: 38px;
  left: 11px;
  top: 8px;
  transform: skewY(-12deg);
}

.insulation-icon::after {
  width: 22px;
  height: 30px;
  left: 19px;
  top: 15px;
  border-color: var(--steel);
  transform: skewY(-12deg);
}

.connector-icon::before {
  width: 44px;
  height: 22px;
  left: 5px;
  top: 16px;
}

.connector-icon::after {
  width: 6px;
  height: 6px;
  left: 15px;
  top: 24px;
  border-radius: 50%;
  box-shadow: 18px 0 0 -2px #fff, 18px 0 0 0 currentColor;
}

.ccs-icon::before {
  width: 24px;
  height: 38px;
  left: 17px;
  top: 8px;
}

.ccs-icon::after {
  width: 34px;
  height: 12px;
  left: 8px;
  top: 29px;
  border-color: var(--steel);
}

.cabinet-icon::before {
  width: 34px;
  height: 38px;
  left: 10px;
  top: 8px;
}

.cabinet-icon::after {
  width: 20px;
  height: 0;
  left: 17px;
  top: 24px;
  border-left: 0;
  border-right: 0;
  border-bottom: 0;
  box-shadow: 0 10px 0 0 currentColor;
}

.split-section {
  width: 100%;
  max-width: none;
  padding-left: max(28px, calc((100vw - var(--max)) / 2));
  padding-right: max(28px, calc((100vw - var(--max)) / 2));
  background: var(--steel-soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.workflow {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
  border-top: 1px solid var(--line-strong);
}

.workflow article {
  position: relative;
  min-height: 184px;
  padding: 28px 30px 20px 0;
  border-right: 1px solid var(--line-strong);
}

.workflow article + article {
  padding-left: 30px;
}

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

.workflow span {
  color: var(--steel);
  font-size: 26px;
  font-weight: 800;
}

.scenarios {
  padding-bottom: 76px;
}

.scenario-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.scenario-list article {
  min-height: 168px;
  padding: 28px 26px;
  border-right: 1px solid var(--line);
}

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

.application-visual {
  position: relative;
  margin: 42px 0 0;
  border: 1px solid var(--line);
  background: var(--graphite);
  overflow: hidden;
}

.application-visual img {
  width: 100%;
  height: 430px;
  object-fit: cover;
}

.application-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(27, 31, 35, 0.84) 0%, rgba(27, 31, 35, 0.52) 34%, rgba(27, 31, 35, 0.08) 68%);
  pointer-events: none;
}

.application-caption {
  position: absolute;
  z-index: 1;
  left: 34px;
  bottom: 34px;
  width: min(420px, calc(100% - 68px));
  color: #fff;
}

.application-caption .section-index {
  color: #7fc3cf;
}

.application-caption h3 {
  margin: 0 0 14px;
  font-size: 28px;
  line-height: 1.15;
}

.application-caption > p:not(.section-index) {
  margin: 0;
  color: #dce7ea;
  line-height: 1.75;
}

.position-band {
  width: 100%;
  max-width: none;
  display: grid;
  grid-template-columns: minmax(280px, 0.72fr) minmax(320px, 1fr);
  gap: 84px;
  align-items: center;
  padding-left: max(28px, calc((100vw - var(--max)) / 2));
  padding-right: max(28px, calc((100vw - var(--max)) / 2));
  background: var(--graphite);
  color: #fff;
}

.position-band .section-index {
  color: #7fc3cf;
}

.position-band > p {
  color: #d9e0e6;
  font-size: 18px;
}

.package-panel {
  display: grid;
  grid-template-columns: minmax(260px, 0.72fr) minmax(420px, 1fr);
  gap: 74px;
  padding: 42px;
  border: 1px solid var(--line);
  background: linear-gradient(135deg, #fff, #f7f9fb);
  box-shadow: var(--shadow);
}

.package-flow {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  align-items: stretch;
  border-left: 1px solid var(--line);
}

.package-flow article {
  padding: 0 26px;
  border-right: 1px solid var(--line);
}

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

.contact-section {
  display: grid;
  grid-template-columns: minmax(280px, 0.78fr) minmax(420px, 1fr);
  gap: 86px;
  align-items: start;
  padding-top: 24px;
}

.contact-copy h2 {
  margin: 0 0 22px;
  font-size: 40px;
  line-height: 1.12;
}

.contact-copy ul {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.contact-copy li {
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.contact-direct {
  display: grid;
  gap: 7px;
  margin-top: 26px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.contact-direct span {
  color: var(--steel);
  font-size: 13px;
  font-weight: 800;
}

.contact-direct a {
  width: fit-content;
  color: var(--ink);
  font-size: 24px;
  font-weight: 800;
  line-height: 1.15;
  border-bottom: 2px solid var(--teal);
}

.contact-direct a:hover {
  color: var(--teal-dark);
}

.contact-form {
  display: grid;
  gap: 18px;
  padding: 32px;
  border: 1px solid var(--line);
  background: #fff;
}

.contact-form label {
  display: grid;
  gap: 8px;
}

.contact-form span {
  color: var(--steel);
  font-size: 13px;
  font-weight: 700;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: #fbfcfd;
  color: var(--ink);
  padding: 13px 14px;
  outline: none;
  resize: vertical;
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--copper);
  background: #fff;
}

.contact-form .button {
  width: fit-content;
  min-width: 160px;
  cursor: pointer;
}

.form-note {
  min-height: 24px;
}

.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 28px max(28px, calc((100vw - var(--max)) / 2));
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

.footer p {
  margin: 0;
}

.footer a {
  color: var(--ink);
  font-weight: 700;
}

@media (max-width: 1060px) {
  .site-header {
    gap: 18px;
  }

  .nav {
    gap: 18px;
  }

  .hero h1 {
    font-size: 54px;
  }

  html[lang="en"] .hero h1 {
    font-size: 50px;
  }

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

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

  .workflow article:nth-child(2) {
    border-right: 0;
  }

  .workflow article:nth-child(n + 3) {
    border-top: 1px solid var(--line-strong);
  }

  .package-panel,
  .contact-section,
  .position-band {
    grid-template-columns: 1fr;
    gap: 36px;
  }
}

@media (max-width: 860px) {
  :root {
    --header-h: 68px;
  }

  .site-header {
    padding: 0 18px;
  }

  .brand {
    min-width: 0;
  }

  .brand-logo {
    width: 132px;
  }

  .brand-tagline,
  .header-cta {
    display: none;
  }

  .lang-toggle {
    min-width: 44px;
    height: 40px;
    padding: 0 10px;
  }

  .menu-button {
    display: block;
  }

  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 10px 18px 18px;
    border-bottom: 1px solid var(--line);
    background: #fff;
  }

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

  .nav a {
    padding: 15px 0;
    border-bottom: 1px solid var(--line);
  }

  .nav a::after {
    display: none;
  }

  .hero {
    min-height: auto;
  }

  .hero-media {
    position: relative;
    inset: auto;
    height: 360px;
    margin-top: var(--header-h);
  }

  .hero-media::before {
    background: linear-gradient(180deg, #fff 0%, rgba(255, 255, 255, 0.15) 70%);
  }

  .hero-media::after {
    height: 110px;
  }

  .hero-media img {
    object-position: center;
  }

  .hero-inner {
    min-height: auto;
    margin-top: -150px;
  }

  .hero-copy {
    padding: 32px 0 54px;
  }

  .hero h1 {
    max-width: 380px;
    font-size: 42px;
  }

  html[lang="en"] .hero h1 {
    font-size: 40px;
  }

  .hero-lead {
    font-size: 17px;
    line-height: 1.75;
  }

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

  .hero-proof div,
  .hero-proof div:nth-child(2),
  .hero-proof div:last-child {
    padding: 14px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .hero-proof div:last-child {
    border-bottom: 0;
  }

  .section {
    width: min(100% - 36px, var(--max));
    padding: 64px 0;
  }

  .section-heading {
    grid-template-columns: 1fr;
    gap: 18px;
    margin-bottom: 30px;
  }

  .section-heading h2,
  .position-band h2,
  .contact-copy h2 {
    font-size: 30px;
  }

  .product-grid,
  .scenario-list,
  .workflow,
  .package-flow {
    grid-template-columns: 1fr;
  }

  .product-card {
    min-height: auto;
    padding: 24px;
  }

  .workflow article,
  .workflow article + article {
    min-height: auto;
    padding: 24px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line-strong);
  }

  .workflow article:last-child {
    border-bottom: 0;
  }

  .scenario-list article {
    min-height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .scenario-list article:last-child {
    border-bottom: 0;
  }

  .application-visual {
    margin-top: 30px;
  }

  .application-visual img {
    height: 360px;
  }

  .application-visual::after {
    background: linear-gradient(180deg, rgba(27, 31, 35, 0.08) 0%, rgba(27, 31, 35, 0.76) 70%);
  }

  .application-caption {
    left: 22px;
    right: 22px;
    bottom: 22px;
    width: auto;
  }

  .application-caption h3 {
    font-size: 23px;
  }

  .position-band,
  .split-section {
    padding-left: 18px;
    padding-right: 18px;
  }

  .package-panel {
    padding: 28px;
  }

  .package-flow {
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .package-flow article {
    padding: 22px 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .package-flow article:last-child {
    border-bottom: 0;
  }

  .contact-section {
    padding-top: 0;
  }

  .contact-form {
    padding: 22px;
  }

  .footer {
    display: grid;
    padding: 24px 18px;
  }
}

@media (max-width: 480px) {
  .brand-logo {
    width: 122px;
  }

  .hero h1 {
    font-size: 36px;
  }

  html[lang="en"] .hero h1 {
    font-size: 35px;
  }

  .hero-actions {
    display: grid;
  }

  .button {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}