:root {
  --primary: #1a2a4a;
  --primary-light: #2d4a7a;
  --primary-dark: #0f1a2e;
  --accent: #4a7ab5;
  --accent-light: #6b9fd4;
  --accent-glow: rgba(74, 122, 181, 0.35);
  --bg: #f0f2f5;
  --bg-alt: #e4e8ee;
  --card-bg: rgba(255, 255, 255, 0.72);
  --card-border: rgba(255, 255, 255, 0.5);
  --text: #1a1a2e;
  --text-secondary: #4a5568;
  --text-muted: #718096;
  --shadow: 0 8px 32px rgba(26, 42, 74, 0.1);
  --shadow-hover: 0 16px 48px rgba(26, 42, 74, 0.18);
  --radius: 16px;
  --radius-sm: 10px;
  --radius-lg: 24px;
  --transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --max-width: 1200px;
  --glass: blur(18px) saturate(180%);
}

@media (prefers-color-scheme: dark) {
  :root {
    --primary: #4a7ab5;
    --primary-light: #6b9fd4;
    --primary-dark: #0a1220;
    --accent: #6b9fd4;
    --accent-light: #8bb8e8;
    --accent-glow: rgba(107, 159, 212, 0.3);
    --bg: #0d1117;
    --bg-alt: #161b22;
    --card-bg: rgba(22, 27, 34, 0.78);
    --card-border: rgba(255, 255, 255, 0.08);
    --text: #e6edf3;
    --text-secondary: #b1bac4;
    --text-muted: #8b949e;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-hover: 0 16px 48px rgba(0, 0, 0, 0.55);
  }
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  font-size: 16px;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background var(--transition), color var(--transition);
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(ellipse 80% 60% at 10% 0%, rgba(74, 122, 181, 0.08) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 90% 20%, rgba(107, 159, 212, 0.06) 0%, transparent 55%),
    radial-gradient(ellipse 70% 60% at 50% 100%, rgba(26, 42, 74, 0.05) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

::selection {
  background: var(--accent);
  color: #fff;
}

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

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition), opacity var(--transition);
}

a:hover {
  color: var(--accent-light);
}

a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

ul, ol {
  list-style: none;
}

/* ===== Header / Nav ===== */
header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.65);
  backdrop-filter: var(--glass);
  -webkit-backdrop-filter: var(--glass);
  border-bottom: 1px solid var(--card-border);
  transition: background var(--transition), box-shadow var(--transition);
}

@media (prefers-color-scheme: dark) {
  header {
    background: rgba(13, 17, 23, 0.72);
  }
}

header:hover {
  box-shadow: 0 4px 24px rgba(26, 42, 74, 0.08);
}

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  gap: 16px;
}

nav > div {
  flex-shrink: 0;
}

nav > div a {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  transition: opacity var(--transition), transform var(--transition);
  display: inline-block;
}

nav > div a:hover {
  opacity: 0.85;
  transform: scale(1.02);
}

nav ul {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}

nav ul li a {
  display: inline-block;
  padding: 8px 14px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  position: relative;
  transition: color var(--transition), background var(--transition), transform var(--transition);
  white-space: nowrap;
}

nav ul li a::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-light));
  border-radius: 2px;
  transform: translateX(-50%);
  transition: width var(--transition);
}

nav ul li a:hover {
  color: var(--primary);
  background: rgba(74, 122, 181, 0.08);
  transform: translateY(-1px);
}

nav ul li a:hover::after {
  width: 60%;
}

/* ===== Main ===== */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 80px;
  position: relative;
  z-index: 1;
}

/* ===== Sections ===== */
section {
  margin-bottom: 56px;
  animation: fadeInUp 0.7s cubic-bezier(0.22, 1, 0.36, 1) both;
}

section:nth-child(1) { animation-delay: 0.05s; }
section:nth-child(2) { animation-delay: 0.1s; }
section:nth-child(3) { animation-delay: 0.15s; }
section:nth-child(4) { animation-delay: 0.2s; }
section:nth-child(5) { animation-delay: 0.25s; }
section:nth-child(6) { animation-delay: 0.3s; }
section:nth-child(7) { animation-delay: 0.35s; }
section:nth-child(8) { animation-delay: 0.4s; }

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(32px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Banner ===== */
#banner {
  margin-top: 32px;
  padding: 64px 48px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, #1a2a4a 0%, #2d4a7a 40%, #4a7ab5 100%);
  color: #fff;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(26, 42, 74, 0.3);
  animation: bannerGlow 6s ease-in-out infinite alternate;
}

@keyframes bannerGlow {
  0% { box-shadow: 0 20px 60px rgba(26, 42, 74, 0.3); }
  100% { box-shadow: 0 20px 80px rgba(74, 122, 181, 0.45); }
}

#banner::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.12) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  animation: floatOrb 12s ease-in-out infinite;
}

#banner::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(107, 159, 212, 0.15) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
  animation: floatOrb 15s ease-in-out infinite reverse;
}

@keyframes floatOrb {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(30px, -20px) scale(1.05); }
  66% { transform: translate(-20px, 15px) scale(0.95); }
}

#banner h1 {
  font-size: clamp(1.6rem, 4vw, 2.6rem);
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
  position: relative;
  z-index: 1;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.15);
}

#banner p {
  font-size: clamp(0.95rem, 1.8vw, 1.1rem);
  line-height: 1.85;
  opacity: 0.92;
  max-width: 820px;
  position: relative;
  z-index: 1;
}

/* ===== Section Headings ===== */
section > h2 {
  font-size: clamp(1.4rem, 3vw, 1.9rem);
  font-weight: 700;
  color: var(--text);
  margin-bottom: 28px;
  padding-bottom: 14px;
  position: relative;
  letter-spacing: -0.01em;
  line-height: 1.35;
}

section > h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 56px;
  height: 4px;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent), var(--accent-light));
  transition: width var(--transition);
}

section:hover > h2::after {
  width: 100px;
}

section > h3 {
  font-size: clamp(1.1rem, 2.2vw, 1.3rem);
  font-weight: 650;
  color: var(--primary);
  margin: 28px 0 12px;
  padding-left: 16px;
  border-left: 4px solid var(--accent);
  line-height: 1.4;
  transition: border-color var(--transition), padding-left var(--transition);
}

section > h3:hover {
  border-left-color: var(--accent-light);
  padding-left: 20px;
}

section > h4 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  margin: 20px 0 10px;
  line-height: 1.4;
}

section > p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.85;
  margin-bottom: 14px;
  max-width: 900px;
}

/* ===== Card-like sections ===== */
#brand,
#products,
#advantages,
#solutions,
#applications,
#cases,
#reviews,
#news,
#articles,
#knowledge,
#faq,
#howto,
#contact,
#sitemap,
#links,
#author,
#legal,
#updatetime {
  background: var(--card-bg);
  backdrop-filter: var(--glass);
  -webkit-backdrop-filter: var(--glass);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 36px 40px;
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}

#brand:hover,
#products:hover,
#advantages:hover,
#solutions:hover,
#applications:hover,
#cases:hover,
#reviews:hover,
#news:hover,
#articles:hover,
#knowledge:hover,
#faq:hover,
#howto:hover,
#contact:hover,
#sitemap:hover,
#links:hover,
#author:hover,
#legal:hover,
#updatetime:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
  border-color: rgba(74, 122, 181, 0.2);
}

/* ===== Blockquote / Reviews ===== */
blockquote {
  position: relative;
  padding: 24px 28px 24px 56px;
  margin: 16px 0;
  background: linear-gradient(135deg, rgba(74, 122, 181, 0.06) 0%, rgba(107, 159, 212, 0.04) 100%);
  border-radius: var(--radius-sm);
  border-left: 4px solid var(--accent);
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
}

blockquote::before {
  content: '\201C';
  position: absolute;
  top: 8px;
  left: 16px;
  font-size: 3rem;
  line-height: 1;
  color: var(--accent);
  opacity: 0.35;
  font-family: Georgia, serif;
}

blockquote:hover {
  background: linear-gradient(135deg, rgba(74, 122, 181, 0.1) 0%, rgba(107, 159, 212, 0.07) 100%);
  transform: translateX(6px);
  box-shadow: 0 4px 20px rgba(74, 122, 181, 0.1);
}

blockquote p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.8;
  font-style: italic;
}

/* ===== Articles ===== */
#news article,
#articles article {
  padding: 24px 0;
  border-bottom: 1px solid rgba(74, 122, 181, 0.1);
  transition: padding var(--transition), background var(--transition);
}

#news article:last-child,
#articles article:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

#news article:first-child,
#articles article:first-child {
  padding-top: 0;
}

#news article:hover,
#articles article:hover {
  padding-left: 12px;
  background: rgba(74, 122, 181, 0.03);
  border-radius: var(--radius-sm);
}

#news article h3,
#articles article h3 {
  font-size: 1.1rem;
  font-weight: 650;
  color: var(--primary);
  margin: 0 0 8px;
  padding: 0;
  border: none;
  line-height: 1.45;
  transition: color var(--transition);
}

#news article:hover h3,
#articles article:hover h3 {
  color: var(--accent);
}

#news article p,
#articles article p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.75;
  margin-bottom: 6px;
}

#articles article p:first-of-type {
  font-size: 0.82rem;
  color: var(--text-muted);
  opacity: 0.8;
}

#articles article a {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent);
  padding: 4px 0;
  position: relative;
  transition: color var(--transition), transform var(--transition);
}

#articles article a::after {
  content: ' →';
  transition: transform var(--transition);
  display: inline-block;
}

#articles article a:hover {
  color: var(--accent-light);
  transform: translateX(4px);
}

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

/* ===== FAQ Details ===== */
#faq details {
  margin-bottom: 10px;
  border-radius: var(--radius-sm);
  background: rgba(74, 122, 181, 0.04);
  border: 1px solid rgba(74, 122, 181, 0.08);
  overflow: hidden;
  transition: background var(--transition), border-color var(--transition), box-shadow var(--transition);
}

#faq details:hover {
  background: rgba(74, 122, 181, 0.07);
  border-color: rgba(74, 122, 181, 0.15);
}

#faq details[open] {
  background: rgba(74, 122, 181, 0.06);
  border-color: rgba(74, 122, 181, 0.18);
  box-shadow: 0 4px 16px rgba(74, 122, 181, 0.08);
}

#faq details summary {
  padding: 16px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  transition: color var(--transition), background var(--transition);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

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

#faq details summary::after {
  content: '+';
  font-size: 1.3rem;
  font-weight: 300;
  color: var(--accent);
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(74, 122, 181, 0.1);
  transition: transform var(--transition), background var(--transition), color var(--transition);
}

#faq details[open] summary::after {
  content: '−';
  transform: rotate(180deg);
  background: var(--accent);
  color: #fff;
}

#faq details summary:hover {
  color: var(--accent);
  background: rgba(74, 122, 181, 0.05);
}

#faq details p {
  padding: 0 20px 18px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.85;
  animation: revealContent 0.35s ease both;
}

@keyframes revealContent {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Sitemap & Links lists ===== */
#sitemap ul,
#links ul {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

#sitemap ul li a,
#links ul li a {
  display: inline-block;
  padding: 8px 18px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: rgba(74, 122, 181, 0.06);
  border: 1px solid rgba(74, 122, 181, 0.1);
  border-radius: 50px;
  transition: all var(--transition);
}

#sitemap ul li a:hover,
#links ul li a:hover {
  color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--accent-glow);
}

/* ===== Contact info ===== */
#contact p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.9;
  margin-bottom: 6px;
}

#contact h3 {
  margin-top: 24px;
}

#contact h3:first-of-type {
  margin-top: 0;
}

/* ===== HowTo steps ===== */
#howto h4 {
  position: relative;
  padding-left: 32px;
  margin-top: 24px;
}

#howto h4::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  box-shadow: 0 2px 8px var(--accent-glow);
}

#howto h4::after {
  content: '';
  position: absolute;
  left: 6px;
  top: calc(50% + 10px);
  width: 3px;
  height: 24px;
  background: linear-gradient(180deg, var(--accent), transparent);
  border-radius: 2px;
}

#howto h4:last-of-type::after {
  display: none;
}

/* ===== Footer ===== */
footer {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 100%);
  color: rgba(255, 255, 255, 0.85);
  padding: 48px 24px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(107, 159, 212, 0.4), transparent);
}

footer p {
  font-size: 0.85rem;
  line-height: 2;
  opacity: 0.8;
  transition: opacity var(--transition);
}

footer p:hover {
  opacity: 1;
}

footer p:first-child {
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 4px;
}

/* ===== Scroll reveal (CSS-only enhancement) ===== */
@media (prefers-reduced-motion: no-preference) {
  section {
    opacity: 0;
    animation: fadeInUp 0.7s cubic-bezier(0.22, 1, 0.36, 1) forwards;
  }
}

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

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  nav {
    padding: 0 20px;
    min-height: 60px;
  }

  nav ul li a {
    padding: 6px 10px;
    font-size: 0.82rem;
  }

  main {
    padding: 0 20px 64px;
  }

  #banner {
    padding: 48px 32px;
    border-radius: var(--radius);
  }

  #brand,
  #products,
  #advantages,
  #solutions,
  #applications,
  #cases,
  #reviews,
  #news,
  #articles,
  #knowledge,
  #faq,
  #howto,
  #contact,
  #sitemap,
  #links,
  #author,
  #legal,
  #updatetime {
    padding: 28px 28px;
  }
}

@media (max-width: 768px) {
  html {
    font-size: 15px;
  }

  nav {
    flex-direction: column;
    align-items: flex-start;
    padding: 12px 16px;
    gap: 8px;
    min-height: auto;
  }

  nav > div {
    width: 100%;
  }

  nav > div a {
    font-size: 1.2rem;
  }

  nav ul {
    width: 100%;
    gap: 2px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    padding-bottom: 4px;
  }

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

  nav ul li a {
    padding: 6px 10px;
    font-size: 0.78rem;
    white-space: nowrap;
  }

  main {
    padding: 0 16px 56px;
  }

  #banner {
    margin-top: 20px;
    padding: 36px 24px;
    border-radius: var(--radius-sm);
  }

  #banner h1 {
    font-size: 1.35rem;
    margin-bottom: 14px;
  }

  #banner p {
    font-size: 0.9rem;
    line-height: 1.75;
  }

  section {
    margin-bottom: 36px;
  }

  section > h2 {
    font-size: 1.25rem;
    margin-bottom: 20px;
    padding-bottom: 10px;
  }

  section > h3 {
    font-size: 1.05rem;
    margin: 20px 0 10px;
    padding-left: 12px;
    border-left-width: 3px;
  }

  section > p {
    font-size: 0.9rem;
  }

  #brand,
  #products,
  #advantages,
  #solutions,
  #applications,
  #cases,
  #reviews,
  #news,
  #articles,
  #knowledge,
  #faq,
  #howto,
  #contact,
  #sitemap,
  #links,
  #author,
  #legal,
  #updatetime {
    padding: 22px 18px;
    border-radius: var(--radius-sm);
  }

  blockquote {
    padding: 18px 18px 18px 44px;
  }

  blockquote::before {
    font-size: 2.4rem;
    left: 12px;
    top: 6px;
  }

  blockquote p {
    font-size: 0.88rem;
  }

  #news article h3,
  #articles article h3 {
    font-size: 1rem;
  }

  #news article p,
  #articles article p {
    font-size: 0.85rem;
  }

  #faq details summary {
    padding: 14px 16px;
    font-size: 0.9rem;
  }

  #faq details p {
    padding: 0 16px 16px;
    font-size: 0.85rem;
  }

  #sitemap ul,
  #links ul {
    gap: 8px;
  }

  #sitemap ul li a,
  #links ul li a {
    padding: 6px 14px;
    font-size: 0.8rem;
  }

  footer {
    padding: 36px 16px;
  }

  footer p {
    font-size: 0.8rem;
  }
}

@media (max-width: 480px) {
  html {
    font-size: 14px;
  }

  #banner {
    padding: 28px 18px;
  }

  #banner h1 {
    font-size: 1.2rem;
  }

  #banner p {
    font-size: 0.85rem;
  }

  section > h2 {
    font-size: 1.15rem;
  }

  section > h3 {
    font-size: 0.98rem;
  }

  #brand,
  #products,
  #advantages,
  #solutions,
  #applications,
  #cases,
  #reviews,
  #news,
  #articles,
  #knowledge,
  #faq,
  #howto,
  #contact,
  #sitemap,
  #links,
  #author,
  #legal,
  #updatetime {
    padding: 18px 14px;
  }

  nav ul li a {
    font-size: 0.75rem;
    padding: 5px 8px;
  }
}

/* ===== Print ===== */
@media print {
  header, footer, #banner::before, #banner::after, body::before {
    display: none;
  }

  body {
    background: #fff;
    color: #000;
  }

  section {
    box-shadow: none;
    border: 1px solid #ddd;
    break-inside: avoid;
    opacity: 1;
    animation: none;
  }

  a {
    color: #000;
    text-decoration: underline;
  }
}