:root {
  --bg: #f5f7fa;
  --bg-alt: #eef1f6;
  --surface: #ffffff;
  --surface-glass: rgba(255, 255, 255, 0.72);
  --surface-glass-strong: rgba(255, 255, 255, 0.9);
  --border: rgba(31, 41, 55, 0.1);
  --border-strong: rgba(31, 41, 55, 0.18);
  --text: #1f2937;
  --text-soft: #4b5563;
  --text-muted: #6b7280;
  --brand: #0f766e;
  --brand-2: #0ea5e9;
  --brand-3: #f59e0b;
  --brand-soft: rgba(15, 118, 110, 0.1);
  --shadow-sm: 0 4px 14px rgba(15, 23, 42, 0.06);
  --shadow: 0 12px 34px rgba(15, 23, 42, 0.1);
  --shadow-lg: 0 24px 60px rgba(15, 23, 42, 0.16);
  --radius-sm: 10px;
  --radius: 18px;
  --radius-lg: 28px;
  --radius-pill: 999px;
  --nav-h: 68px;
  --maxw: 1180px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --dur: 0.45s;
  --grad-banner: linear-gradient(135deg, #0f766e 0%, #0ea5e9 46%, #6366f1 100%);
  --grad-soft: linear-gradient(135deg, rgba(15, 118, 110, 0.12), rgba(14, 165, 233, 0.12));
  --grad-text: linear-gradient(120deg, #0f766e, #0ea5e9 55%, #6366f1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1120;
    --bg-alt: #0f172a;
    --surface: #131c31;
    --surface-glass: rgba(19, 28, 49, 0.7);
    --surface-glass-strong: rgba(19, 28, 49, 0.9);
    --border: rgba(148, 163, 184, 0.16);
    --border-strong: rgba(148, 163, 184, 0.28);
    --text: #e8eef7;
    --text-soft: #c3ccdb;
    --text-muted: #93a1b6;
    --brand: #2dd4bf;
    --brand-2: #38bdf8;
    --brand-3: #fbbf24;
    --brand-soft: rgba(45, 212, 191, 0.14);
    --shadow-sm: 0 4px 14px rgba(0, 0, 0, 0.4);
    --shadow: 0 14px 38px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 26px 64px rgba(0, 0, 0, 0.6);
    --grad-banner: linear-gradient(135deg, #0b3b3a 0%, #0c4a6e 46%, #312e81 100%);
    --grad-soft: linear-gradient(135deg, rgba(45, 212, 191, 0.14), rgba(56, 189, 248, 0.12));
    --grad-text: linear-gradient(120deg, #2dd4bf, #38bdf8 55%, #a5b4fc);
  }
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 16px);
}

body {
  margin: 0;
  padding: 0;
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    radial-gradient(1200px 600px at 12% -8%, rgba(14, 165, 233, 0.14), transparent 60%),
    radial-gradient(900px 520px at 92% 4%, rgba(99, 102, 241, 0.14), transparent 62%),
    radial-gradient(1000px 600px at 50% 110%, rgba(15, 118, 110, 0.1), transparent 65%);
  background-attachment: fixed;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.4s var(--ease), color 0.4s var(--ease);
}

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

a {
  color: var(--brand);
  text-decoration: none;
  transition: color 0.28s var(--ease), opacity 0.28s var(--ease);
}

a:hover,
a:focus-visible {
  color: var(--brand-2);
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--brand-2);
  outline-offset: 3px;
  border-radius: 6px;
}

::selection {
  background: var(--brand-soft);
  color: var(--text);
}

/* ---------- Header / Nav ---------- */

header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 0 20px;
  background: var(--surface-glass);
  -webkit-backdrop-filter: saturate(180%) blur(18px);
  backdrop-filter: saturate(180%) blur(18px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.04), var(--shadow-sm);
  animation: slideDown 0.6s var(--ease) both;
}

header nav {
  max-width: var(--maxw);
  margin: 0 auto;
  min-height: var(--nav-h);
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

header nav > a:first-child {
  font-size: 1.3rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  padding: 8px 4px;
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  white-space: nowrap;
  transition: transform 0.35s var(--ease), filter 0.35s var(--ease);
}

header nav > a:first-child:hover {
  transform: translateY(-1px) scale(1.02);
  filter: brightness(1.12);
}

header nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
  margin-left: auto;
}

header nav ul li a {
  display: inline-block;
  padding: 8px 13px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-soft);
  border-radius: var(--radius-pill);
  position: relative;
  transition: color 0.3s var(--ease), background-color 0.3s var(--ease), transform 0.3s var(--ease);
}

header nav ul li a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 3px;
  width: 0;
  height: 2px;
  border-radius: 2px;
  background: var(--grad-text);
  transform: translateX(-50%);
  transition: width 0.34s var(--ease);
}

header nav ul li a:hover,
header nav ul li a:focus-visible {
  color: var(--brand);
  background: var(--brand-soft);
  transform: translateY(-2px);
}

header nav ul li a:hover::after,
header nav ul li a:focus-visible::after {
  width: 46%;
}

/* ---------- Main / Sections ---------- */

main {
  display: block;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px 40px;
}

section {
  position: relative;
  margin: 34px 0;
  padding: 34px 32px;
  background: var(--surface-glass);
  -webkit-backdrop-filter: saturate(160%) blur(16px);
  backdrop-filter: saturate(160%) blur(16px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  animation: fadeUp 0.7s var(--ease) both;
  transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease), border-color 0.4s var(--ease);
}

section:hover {
  box-shadow: var(--shadow);
  border-color: var(--border-strong);
}

section:nth-of-type(odd) {
  animation-delay: 0.05s;
}

section:nth-of-type(even) {
  animation-delay: 0.1s;
}

/* ---------- Hero ---------- */

#hero {
  margin-top: 30px;
  padding: 56px 40px 44px;
  border: none;
  border-radius: var(--radius-lg);
  background: var(--grad-banner);
  background-size: 200% 200%;
  color: #f8fafc;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  animation: fadeUp 0.7s var(--ease) both, bannerShift 16s ease-in-out infinite alternate;
}

#hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(560px 300px at 88% 0%, rgba(255, 255, 255, 0.22), transparent 65%),
    radial-gradient(480px 280px at 0% 100%, rgba(255, 255, 255, 0.16), transparent 62%);
  pointer-events: none;
}

#hero::after {
  content: "";
  position: absolute;
  top: -60%;
  left: -30%;
  width: 60%;
  height: 220%;
  background: linear-gradient(100deg, transparent, rgba(255, 255, 255, 0.14), transparent);
  transform: rotate(14deg);
  animation: sheen 7s ease-in-out infinite;
  pointer-events: none;
}

#hero > * {
  position: relative;
  z-index: 1;
}

#hero h1 {
  margin: 0 0 18px;
  font-size: clamp(1.7rem, 4.2vw, 2.9rem);
  line-height: 1.28;
  font-weight: 800;
  letter-spacing: 0.01em;
  text-shadow: 0 2px 18px rgba(0, 0, 0, 0.18);
}

#hero > p {
  margin: 0 0 26px;
  max-width: 62ch;
  font-size: clamp(0.98rem, 1.6vw, 1.08rem);
  line-height: 1.85;
  color: rgba(248, 250, 252, 0.94);
}

#hero nav {
  margin-top: 22px;
}

#hero nav ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 16px;
  padding: 0;
  font-size: 0.86rem;
}

#hero nav ol li {
  display: flex;
  align-items: center;
  gap: 8px;
  color: rgba(248, 250, 252, 0.82);
}

#hero nav ol li + li::before {
  content: "/";
  color: rgba(248, 250, 252, 0.5);
  margin-right: 2px;
}

#hero nav ol li a {
  color: rgba(248, 250, 252, 0.9);
  padding: 2px 6px;
  border-radius: 6px;
  transition: background-color 0.3s var(--ease), color 0.3s var(--ease);
}

#hero nav ol li a:hover {
  background: rgba(255, 255, 255, 0.16);
  color: #ffffff;
}

#hero nav[aria-label="页内导航"] ul {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

#hero nav[aria-label="页内导航"] ul li a {
  display: inline-block;
  padding: 8px 16px;
  font-size: 0.86rem;
  font-weight: 600;
  color: #f8fafc;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: var(--radius-pill);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: transform 0.3s var(--ease), background-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

#hero nav[aria-label="页内导航"] ul li a:hover,
#hero nav[aria-label="页内导航"] ul li a:focus-visible {
  background: rgba(255, 255, 255, 0.28);
  color: #ffffff;
  transform: translateY(-3px);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.22);
}

/* ---------- Typography ---------- */

h2 {
  position: relative;
  margin: 0 0 22px;
  padding-bottom: 14px;
  font-size: clamp(1.35rem, 2.6vw, 1.85rem);
  line-height: 1.35;
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--text);
}

h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 62px;
  height: 4px;
  border-radius: 4px;
  background: var(--grad-text);
  transition: width 0.5s var(--ease);
}

section:hover h2::after {
  width: 110px;
}

h3 {
  margin: 30px 0 12px;
  font-size: clamp(1.08rem, 1.9vw, 1.28rem);
  line-height: 1.5;
  font-weight: 700;
  color: var(--text);
}

h4 {
  margin: 20px 0 10px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--brand);
  letter-spacing: 0.02em;
}

p {
  margin: 0 0 16px;
  color: var(--text-soft);
  line-height: 1.9;
}

p:last-child {
  margin-bottom: 0;
}

strong {
  color: var(--text);
  font-weight: 700;
}

/* ---------- Cards: articles, news, cases, faq, solutions ---------- */

#products h3,
#solutions h3,
#cases h3,
#news h3,
#faq h3,
#howto h3,
#contact h3 {
  position: relative;
  padding: 18px 22px 16px;
  margin: 22px 0 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.38s var(--ease), box-shadow 0.38s var(--ease), border-color 0.38s var(--ease);
}

#products h3::before,
#solutions h3::before,
#cases h3::before,
#news h3::before,
#faq h3::before,
#howto h3::before,
#contact h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  bottom: 16px;
  width: 4px;
  border-radius: 0 4px 4px 0;
  background: var(--grad-text);
  opacity: 0.9;
}

#products h3:hover,
#solutions h3:hover,
#cases h3:hover,
#news h3:hover,
#faq h3:hover,
#howto h3:hover,
#contact h3:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: var(--border-strong);
}

#products h4 {
  display: inline-block;
  padding: 6px 14px;
  margin: 18px 0 10px;
  background: var(--brand-soft);
  border-radius: var(--radius-pill);
  font-size: 0.92rem;
}

article {
  position: relative;
  margin: 20px 0;
  padding: 24px 26px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: transform 0.42s var(--ease), box-shadow 0.42s var(--ease), border-color 0.42s var(--ease);
}

article::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 4px;
  background: var(--grad-text);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 0.45s var(--ease);
}

article:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow);
  border-color: var(--border-strong);
}

article:hover::before {
  transform: scaleY(1);
}

article h3 {
  margin: 0 0 10px;
  padding: 0;
  background: none;
  border: none;
  box-shadow: none;
  font-size: 1.12rem;
}

article h3::before {
  display: none;
}

article p:first-of-type {
  font-size: 0.84rem;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

article p a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  font-size: 0.88rem;
  font-weight: 600;
  color: #ffffff;
  background: var(--grad-banner);
  border-radius: var(--radius-pill);
  box-shadow: 0 6px 18px rgba(14, 165, 233, 0.28);
  transition: transform 0.32s var(--ease), box-shadow 0.32s var(--ease), filter 0.32s var(--ease);
}

article p a::after {
  content: "→";
  transition: transform 0.32s var(--ease);
}

article p a:hover,
article p a:focus-visible {
  color: #ffffff;
  transform: translateY(-2px);
  filter: brightness(1.08);
  box-shadow: 0 12px 26px rgba(14, 165, 233, 0.4);
}

article p a:hover::after {
  transform: translateX(4px);
}

#cases p:nth-of-type(odd) {
  position: relative;
  margin: 12px 0;
  padding: 16px 20px 16px 46px;
  background: var(--grad-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-style: italic;
  color: var(--text-soft);
  transition: transform 0.36s var(--ease), box-shadow 0.36s var(--ease);
}

#cases p:nth-of-type(odd)::before {
  content: "“";
  position: absolute;
  left: 16px;
  top: 8px;
  font-size: 2.4rem;
  line-height: 1;
  font-family: Georgia, "Times New Roman", serif;
  background: var(--grad-text);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
  opacity: 0.85;
}

#cases p:nth-of-type(odd):hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-sm);
}

/* ---------- FAQ ---------- */

#faq h3 {
  cursor: default;
}

#faq h3 + p {
  margin-top: -4px;
  padding: 0 22px 18px;
  color: var(--text-soft);
}

/* ---------- Lists: sitemap, links ---------- */

#sitemap ul,
#links ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 12px;
}

#sitemap ul li a,
#links ul li a {
  display: block;
  padding: 12px 18px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-soft);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
  transition: transform 0.34s var(--ease), color 0.34s var(--ease), border-color 0.34s var(--ease), box-shadow 0.34s var(--ease), background-color 0.34s var(--ease);
}

#sitemap ul li a:hover,
#links ul li a:hover,
#sitemap ul li a:focus-visible,
#links ul li a:focus-visible {
  color: var(--brand);
  background: var(--brand-soft);
  border-color: var(--brand);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}

/* ---------- Legal ---------- */

#legal h2 {
  margin-top: 34px;
}

#legal h2:first-child {
  margin-top: 0;
}

#legal p {
  padding-left: 18px;
  border-left: 3px solid var(--brand-soft);
}

/* ---------- Footer ---------- */

footer {
  position: relative;
  margin-top: 40px;
  padding: 44px 20px 36px;
  text-align: center;
  color: var(--text-muted);
  background: var(--surface-glass-strong);
  -webkit-backdrop-filter: saturate(160%) blur(16px);
  backdrop-filter: saturate(160%) blur(16px);
  border-top: 1px solid var(--border);
}

footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--grad-banner);
  background-size: 200% 100%;
  animation: bannerShift 8s linear infinite alternate;
}

footer p {
  max-width: var(--maxw);
  margin: 0 auto 10px;
  font-size: 0.88rem;
  line-height: 1.8;
  color: var(--text-muted);
}

footer p:first-child {
  font-weight: 600;
  color: var(--text-soft);
}

footer p:last-child {
  margin-bottom: 0;
}

/* ---------- Scroll animations ---------- */

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(26px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-100%);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes bannerShift {
  0% {
    background-position: 0% 50%;
  }
  100% {
    background-position: 100% 50%;
  }
}

@keyframes sheen {
  0% {
    transform: translateX(-40%) rotate(14deg);
    opacity: 0;
  }
  35% {
    opacity: 1;
  }
  100% {
    transform: translateX(320%) rotate(14deg);
    opacity: 0;
  }
}

/* ---------- Responsive: tablet ---------- */

@media (max-width: 900px) {
  :root {
    --radius-lg: 22px;
  }

  header {
    padding: 0 14px;
  }

  header nav {
    gap: 12px;
    padding: 10px 0;
  }

  header nav ul {
    width: 100%;
    margin-left: 0;
    gap: 2px;
    padding-bottom: 6px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  header nav ul::-webkit-scrollbar {
    display: none;
  }

  header nav ul li a {
    white-space: nowrap;
    font-size: 0.85rem;
    padding: 7px 11px;
  }

  main {
    padding: 0 14px 30px;
  }

  section {
    margin: 24px 0;
    padding: 26px 20px;
    border-radius: var(--radius);
  }

  #hero {
    padding: 40px 24px 34px;
  }

  #hero h1 {
    font-size: clamp(1.5rem, 5.4vw, 2.1rem);
  }

  article {
    padding: 20px 18px;
  }

  #products h3,
  #solutions h3,
  #cases h3,
  #news h3,
  #faq h3,
  #howto h3,
  #contact h3 {
    padding: 15px 18px 13px;
  }

  #faq h3 + p {
    padding: 0 18px 16px;
  }
}

/* ---------- Responsive: mobile ---------- */

@media (max-width: 560px) {
  body {
    font-size: 15.5px;
    line-height: 1.72;
  }

  :root {
    --nav-h: 60px;
  }

  header nav > a:first-child {
    font-size: 1.15rem;
  }

  #hero {
    padding: 32px 18px 28px;
    border-radius: var(--radius);
  }

  #hero > p {
    font-size: 0.96rem;
    line-height: 1.8;
  }

  #hero nav[aria-label="页内导航"] ul {
    gap: 8px;
  }

  #hero nav[aria-label="页内导航"] ul li a {
    padding: 7px 13px;
    font-size: 0.8rem;
  }

  section {
    padding: 22px 16px;
    margin: 18px 0;
  }

  h2 {
    font-size: 1.28rem;
    padding-bottom: 12px;
  }

  h2::after {
    width: 48px;
  }

  h3 {
    font-size: 1.04rem;
  }

  article {
    padding: 18px 15px;
  }

  #cases p:nth-of-type(odd) {
    padding: 14px 16px 14px 40px;
  }

  #sitemap ul,
  #links ul {
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }

  #sitemap ul li a,
  #links ul li a {
    padding: 10px 12px;
    font-size: 0.84rem;
    text-align: center;
  }

  footer {
    padding: 32px 16px 28px;
  }

  footer p {
    font-size: 0.82rem;
  }
}

/* ---------- Reduced motion ---------- */

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

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  #hero::after {
    display: none;
  }
}

/* ---------- Print ---------- */

@media print {
  header,
  footer,
  #hero nav,
  #links,
  #sitemap {
    display: none;
  }

  body {
    background: #ffffff;
    color: #000000;
  }

  section {
    box-shadow: none;
    border: 1px solid #cccccc;
    page-break-inside: avoid;
  }
}