*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-cn);
  color: var(--ink);
  background: var(--surface);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--navy);
}

p {
  margin: 0;
}

ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 2rem;
  padding: 0 clamp(1.25rem, 4vw, 3rem);
  background: var(--white);
  border-bottom: 1px solid rgba(15, 23, 42, 0.06);
  transition: border-color 0.2s ease;
}

.site-header.is-scrolled {
  border-bottom-color: rgba(15, 23, 42, 0.08);
  box-shadow: none;
}

.brand-logo {
  height: 36px;
  width: auto;
}

.nav {
  display: flex;
  align-self: stretch;
  align-items: stretch;
  gap: 1.5rem;
  margin-left: auto;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--navy);
}

.nav > a,
.nav-item > a {
  position: relative;
  display: flex;
  align-items: center;
  height: 100%;
  padding: 0;
  transition: color 0.2s ease;
}

.nav > a:hover,
.nav-item > a:hover,
.nav > a.is-active {
  color: var(--cyan-deep);
}

.nav-item {
  position: relative;
  display: flex;
  align-items: stretch;
}

.submenu {
  /* 由 JS 设为：top = header.bottom - 10px；left = 导航项 left - 6px */
  position: fixed;
  top: calc(var(--header-h) - 10px);
  left: 0;
  transform: none;
  min-width: 140px;
  padding: 0.5rem 0;
  background: var(--white);
  border: 1px solid var(--line);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s ease;
  z-index: 60;
}

/* 菜单略侵入标题栏，hover 自然可点选，无需额外空隙桥接 */
.submenu::before {
  display: none;
}

.nav-item:hover .submenu,
.nav-item:focus-within .submenu {
  opacity: 1;
  pointer-events: auto;
}

.submenu a {
  display: block;
  padding: 0.6rem 1rem;
  font-size: 0.875rem;
  color: var(--muted);
}

.submenu a:hover {
  color: var(--navy);
  background: var(--soft);
}

.header-cta {
  flex-shrink: 0;
}

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  border: 0;
  background: transparent;
  margin-left: auto;
}
.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 5px auto;
  background: var(--navy);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 1.35rem;
  font-family: inherit;
  font-size: 0.9375rem;
  font-weight: 500;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn-primary {
  background: var(--cyan);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--cyan-deep);
  color: var(--white);
}

.btn-ghost {
  background: transparent;
  border-color: rgba(11, 31, 58, 0.25);
  color: var(--navy);
}

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

.btn-on-dark {
  background: transparent;
  border-color: rgba(255, 255, 255, 0.45);
  color: var(--white);
}

.btn-on-dark:hover {
  border-color: var(--white);
  color: var(--white);
  background: rgba(255, 255, 255, 0.08);
}

.text-link {
  display: inline-flex;
  margin-top: 1.5rem;
  font-weight: 500;
  color: var(--cyan-deep);
  transition: letter-spacing 0.2s ease;
}

.text-link:hover {
  letter-spacing: 0.02em;
}

/* Hero */
.hero {
  position: relative;
  min-height: calc(100vh - var(--header-h));
  display: flex;
  align-items: center;
  overflow: hidden;
  isolation: isolate;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -1;
  background: var(--white);
}

.hero-bg::after {
  display: none;
}

.hero-inner {
  --hero-inline-pad: clamp(1.25rem, 4vw, 3rem);
  width: min(100%, var(--max));
  margin: 0 auto;
  padding: 4.5rem var(--hero-inline-pad) 5rem;
  animation: rise 0.9s ease both;
  position: relative;
}

.eyebrow {
  font-family: var(--font-en);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cyan-deep);
  margin-bottom: 1rem;
}

.hero-title {
  font-size: clamp(2.4rem, 5.5vw, 4.25rem);
  font-weight: 900;
  max-width: 12em;
}

.hero-subtitle {
  margin-top: 1.1rem;
  font-size: clamp(1.15rem, 2vw, 1.5rem);
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1.4;
  color: var(--cyan);
}

.hero-lead {
  margin-top: 1rem;
  max-width: none;
  font-size: 1.0625rem;
  color: var(--muted);
  font-weight: 400;
  white-space: nowrap;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 2.25rem;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Sections */
.section {
  padding: clamp(4rem, 8vw, 6.5rem) clamp(1.25rem, 4vw, 3rem);
}

.solutions,
.cases {
  background: var(--soft);
}

.section-head {
  width: min(100%, var(--max));
  margin: 0 auto 3rem;
}

.section-head h2 {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 700;
}

.section-desc {
  margin-top: 0.75rem;
  max-width: 36rem;
  color: var(--muted);
}

/* Industry blocks */
.industry {
  width: min(100%, var(--max));
  margin: 0 auto 2.5rem;
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  align-items: stretch;
  min-height: 420px;
  background: var(--white);
  border: 1px solid var(--line);
  overflow: hidden;
}

.industry:last-child {
  margin-bottom: 0;
}

.industry-reverse {
  direction: rtl;
}

.industry-reverse > * {
  direction: ltr;
}

.industry-copy {
  height: 100%;
  padding: clamp(2rem, 4vw, 3.25rem);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.industry-tag {
  font-family: var(--font-en);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: var(--cyan-deep);
  margin-bottom: 0.85rem;
}

.industry-copy h3 {
  font-size: clamp(1.4rem, 2.4vw, 1.85rem);
  font-weight: 700;
  margin-bottom: 0.85rem;
}

.industry-copy > p {
  color: var(--muted);
  margin-bottom: 1.25rem;
}

.industry-copy ul li {
  position: relative;
  padding-left: 1rem;
  margin-bottom: 0.45rem;
  color: var(--navy);
  font-size: 0.95rem;
}

.industry-copy ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--cyan);
}

.industry-visual {
  position: relative;
  box-sizing: border-box;
  align-self: stretch;
  height: 100%;
  min-height: 100%;
  /* 配图相对容器各边收进 3px，高度与文字区网格拉伸对齐 */
  padding: 3px;
  background-color: var(--white);
  background-origin: content-box;
  background-clip: content-box;
}

.visual-auto {
  background:
    linear-gradient(135deg, rgba(11, 31, 58, 0.55), rgba(0, 56, 144, 0.25)),
    url("../assets/industry-auto.jpg") center/cover no-repeat;
  background-origin: content-box;
  background-clip: content-box;
}

.visual-mfg {
  background:
    linear-gradient(150deg, rgba(0, 56, 144, 0.2), rgba(11, 31, 58, 0.65)),
    url("../assets/industry-mfg.jpg") center/cover no-repeat;
  background-origin: content-box;
  background-clip: content-box;
}

.visual-ops {
  background:
    radial-gradient(circle at 70% 30%, rgba(0, 56, 144, 0.28), transparent 45%),
    linear-gradient(160deg, rgba(11, 31, 58, 0.55), rgba(6, 18, 36, 0.75)),
    url("../assets/industry-ops.jpg") center/cover no-repeat;
  background-origin: content-box;
  background-clip: content-box;
}

.industry-visual::after {
  content: "";
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.35), 40px 0 0 -3px rgba(0, 56, 144, 0.45);
  top: calc(18% + 3px);
  right: calc(18% + 3px);
}

/* Platforms */
.platforms {
  background: var(--white);
  border-block: 1px solid var(--line);
}

.platform-row {
  width: min(100%, var(--max));
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
}

.platform {
  padding: 1.75rem 1.5rem 1.75rem 0;
  border-top: 1px solid var(--line);
  transition: border-color 0.25s ease;
}

.platform + .platform {
  padding-left: 1.75rem;
  border-left: 1px solid var(--line);
}

.platform:hover {
  border-top-color: var(--cyan);
}

.platform-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan);
  margin-bottom: 1rem;
}

.platform h3 {
  font-family: var(--font-en);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.platform-full {
  margin: 0.35rem 0 0.85rem;
  font-size: 0.8125rem;
  color: var(--muted);
}

.platform > p:last-of-type {
  color: var(--muted);
  font-size: 0.9375rem;
}

/* Cases */
.case-grid {
  width: min(100%, var(--max));
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.case {
  display: block;
  padding: 1.75rem 1.5rem;
  background: var(--white);
  transition: background 0.25s ease;
}

.case:hover {
  background: var(--soft);
}

.case-label {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--cyan-deep);
  margin-bottom: 0.65rem;
}

.case h3 {
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
}

.case p {
  color: var(--muted);
  font-size: 0.9375rem;
}

/* About */
.about {
  background: var(--soft);
}

.about-grid {
  width: min(100%, var(--max));
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 3rem;
  align-items: start;
}

.about-lead {
  margin-top: 1rem;
  font-size: 1.0625rem;
  color: var(--navy);
}

.about-meta {
  margin-top: 1rem;
  color: var(--muted);
  font-size: 0.95rem;
}

.about-values {
  display: grid;
  gap: 1.25rem;
}

.about-values > div {
  padding-bottom: 1.25rem;
  border-bottom: 1px solid rgba(11, 31, 58, 0.12);
}

.about-values h3 {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--cyan-deep);
  margin-bottom: 0.35rem;
}

.about-values p {
  font-size: 1.05rem;
  color: var(--navy);
}

/* CTA */
.cta-band {
  background: var(--cyan);
  color: var(--white);
  padding: clamp(3.5rem, 7vw, 5rem) clamp(1.25rem, 4vw, 3rem);
}

.cta-inner {
  width: min(100%, var(--max));
  margin: 0 auto;
  text-align: center;
}

.cta-inner h2 {
  color: var(--white);
  font-size: clamp(1.6rem, 3vw, 2.25rem);
}

.cta-inner > p {
  margin: 0.85rem auto 0;
  max-width: 28rem;
  color: rgba(255, 255, 255, 0.72);
}

.cta-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.85rem;
  margin-top: 1.75rem;
}

/* Footer */
.site-footer {
  background: #071525;
  color: rgba(255, 255, 255, 0.7);
  padding: 3rem clamp(1.25rem, 4vw, 3rem) 1.5rem;
}

.footer-grid {
  width: min(100%, var(--max));
  margin: 0 auto;
  display: grid;
  /* 品牌列 + 解决方案 / 产品与平台 / 联系我们 三列同宽 */
  grid-template-columns: 1.4fr repeat(3, minmax(0, 1fr));
  gap: 2rem;
  align-items: start;
}

.footer-logo {
  height: 32px;
  width: auto;
  margin-bottom: 1rem;
  filter: brightness(0) invert(1);
}

.footer-brand {
  display: flex;
  align-items: center;
  align-self: center;
  gap: 1rem;
}

.footer-logo-v {
  display: block;
  width: auto;
  flex-shrink: 0;
  /* 高度由 JS 严格限定为文字块高度 + 2px */
  height: auto;
  max-height: none;
  object-fit: contain;
}

.footer-brand p {
  margin: 0;
  line-height: 1.55;
  max-width: 16em;
}

.footer-grid h4 {
  color: var(--white);
  font-size: 0.875rem;
  margin-bottom: 0.85rem;
}

.footer-grid a,
.footer-grid p {
  display: block;
  font-size: 0.875rem;
  margin-bottom: 0.4rem;
  color: rgba(255, 255, 255, 0.65);
}

.footer-grid a:hover {
  color: var(--accent-on-dark);
}

/* 联系我们：与另两列同宽；邮箱不换行；地址可换行 */
.footer-contact {
  width: 100%;
  min-width: 0;
}

.footer-contact-line {
  white-space: nowrap;
}

.footer-contact-addr {
  white-space: normal;
}

.footer-contact a {
  display: inline;
}

.copyright {
  width: min(100%, var(--max));
  margin: 2.5rem auto 0;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.4);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 0.75rem 1.25rem;
}

.copyright .beian {
  color: rgba(255, 255, 255, 0.4);
  cursor: pointer;
  text-decoration: none;
}

.copyright .beian:hover {
  color: var(--accent-on-dark);
  text-decoration: underline;
}

/* Responsive */
@media (max-width: 960px) {
  .site-header {
    justify-content: space-between;
  }

  .nav-toggle { display: inline-block; }
  .nav {
    display: none;
    position: fixed;
    inset: var(--header-h) 0 0 0;
    flex-direction: column;
    gap: 0;
    padding: 1rem 1.25rem 2rem;
    background: var(--surface);
    border-top: 1px solid var(--line);
  }
  .nav.is-open { display: flex; }
  .nav > a,
  .nav-item > a {
    height: auto;
    padding: 0.85rem 0;
    border-bottom: 1px solid var(--line);
  }
  .nav-item > a { border-bottom: none; }
  .submenu {
    position: static !important;
    top: auto !important;
    left: auto !important;
    transform: none !important;
    opacity: 1;
    pointer-events: auto;
    min-width: 0;
    padding: 0;
    background: transparent;
    border: 0;
  }
  .submenu::before {
    display: none;
  }
  .submenu a {
    padding: 0.65rem 0 0.65rem 1rem;
    font-size: 0.875rem;
    border-bottom: 1px solid var(--line);
  }
  body.nav-open { overflow: hidden; }

  .header-cta {
    margin-left: auto;
  }

  .industry,
  .industry-reverse {
    grid-template-columns: 1fr;
    direction: ltr;
  }

  .industry-visual {
    min-height: 280px;
    height: auto;
  }

  .platform-row {
    grid-template-columns: 1fr;
  }

  .platform + .platform {
    padding-left: 0;
    border-left: none;
  }

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

  .about-grid,
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.75rem;
  }

  .hero-title {
    max-width: none;
  }

  .hero-lead {
    white-space: normal;
  }
}

/* Mobile preview helper class applied via viewport */
@media (max-width: 480px) {
  .site-header {
    gap: 1rem;
  }

  .brand-logo {
    height: 28px;
  }

  .header-cta {
    font-size: 0.8125rem;
    min-height: 38px;
    padding: 0 0.9rem;
  }

  .hero {
    min-height: auto;
  }

  .hero-inner {
    padding-top: 3rem;
    padding-bottom: 3.5rem;
  }
}

/* FAQ：列表宽 98%，左缘与「常见问题」标题对齐 */
.faq-list {
  width: min(98%, calc(var(--max) * 0.98));
  max-width: none;
  margin: 0 auto 0 max(0px, calc((100% - min(100%, var(--max))) / 2));
  display: grid;
  gap: 0.75rem;
}

.faq-item {
  border-bottom: 1px solid var(--border, #e6e8ec);
  padding: 0.35rem 0 0.85rem;
}

.faq-item summary {
  cursor: pointer;
  list-style: none;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ink, #12151c);
  padding: 0.55rem 0;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  float: right;
  color: var(--brand, #003890);
  font-weight: 500;
}

.faq-item[open] summary::after {
  content: "–";
}

.faq-item p {
  margin: 0;
  color: var(--muted, #5a6070);
  line-height: 1.7;
  padding-bottom: 0.35rem;
}

.faq-item a {
  color: var(--brand, #003890);
}

/* Scroll reveal */
@media (prefers-reduced-motion: no-preference) {
  .reveal {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.6s ease, transform 0.6s ease;
  }

  .reveal.is-visible {
    opacity: 1;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .hero-inner {
    animation: none;
  }
}


/* Hero circle: absolute; 右边距与左侧留白一致 */
.hero-copy {
  position: relative;
  z-index: 1;
  max-width: max-content;
}

.hero .hero-lead {
  white-space: nowrap;
  max-width: none;
}

.hero-visual {
  position: absolute;
  /* 再略向右伸出内容区 */
  right: clamp(-1.75rem, -2.5vw, -0.75rem);
  top: 46%;
  z-index: 0;
  transform: translateY(-50%);
  pointer-events: none;
  width: min(48vw, 560px);
}

.hero-circle {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1;
  border-radius: 50%;
  object-fit: cover;
  background: #fff;
  opacity: 0.5;
}

@media (max-width: 960px) {
  .hero .hero-lead {
    white-space: normal;
  }

  .hero-copy {
    max-width: none;
  }

  .hero-visual {
    position: relative;
    right: auto;
    top: auto;
    margin: 0 auto 1.5rem;
    transform: none;
    width: min(70vw, 300px);
  }

  .hero-circle {
    opacity: 0.5;
  }
}