:root {
  --bg: #0f0f1a;
  --bg-alt: #16162a;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-solid: #1c1c30;
  --border: rgba(255, 255, 255, 0.08);
  --text: #e8e8f0;
  --text-muted: #a0a0b8;
  --text-dim: #70708a;
  --accent: #e94560;
  --accent-2: #9b51e0;
  --accent-3: #f5a623;
  --gradient-hero: linear-gradient(135deg, #1a1a2e 0%, #16213e 40%, #0f3460 70%, #533483 100%);
  --gradient-accent: linear-gradient(135deg, #e94560 0%, #9b51e0 100%);
  --gradient-card: linear-gradient(145deg, rgba(233, 69, 96, 0.08), rgba(155, 81, 224, 0.05));
  --radius-sm: 8px;
  --radius: 16px;
  --radius-lg: 24px;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
  --shadow-hover: 0 16px 48px rgba(0, 0, 0, 0.5);
  --glass-bg: rgba(28, 28, 48, 0.55);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-blur: blur(16px);
  --transition: 0.3s 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;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f5f5fa;
    --bg-alt: #ffffff;
    --surface: rgba(255, 255, 255, 0.7);
    --surface-solid: #ffffff;
    --border: rgba(0, 0, 0, 0.08);
    --text: #1a1a2e;
    --text-muted: #555570;
    --text-dim: #8888a0;
    --gradient-hero: linear-gradient(135deg, #e8e8f5 0%, #dce4f5 40%, #d0daf0 70%, #e4d8f5 100%);
    --gradient-card: linear-gradient(145deg, rgba(233, 69, 96, 0.06), rgba(155, 81, 224, 0.04));
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
    --shadow-hover: 0 16px 48px rgba(0, 0, 0, 0.14);
    --glass-bg: rgba(255, 255, 255, 0.6);
    --glass-border: rgba(0, 0, 0, 0.06);
  }
}

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

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

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

body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

a:hover {
  color: var(--accent-2);
}

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

.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  z-index: 9999;
  padding: 12px 24px;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: top var(--transition);
}

.skip-link:focus {
  top: 16px;
  color: #fff;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  transition: background var(--transition), box-shadow var(--transition);
}

.site-header:hover {
  box-shadow: var(--shadow);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.brand-logo {
  border-radius: var(--radius-sm);
  transition: transform var(--transition), box-shadow var(--transition);
}

.brand:hover .brand-logo {
  transform: rotate(-6deg) scale(1.08);
  box-shadow: 0 4px 20px rgba(233, 69, 96, 0.5);
}

.brand-name {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  white-space: nowrap;
}

.main-nav ul {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  flex-wrap: wrap;
}

.main-nav a {
  display: block;
  padding: 8px 14px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  position: relative;
  transition: color var(--transition), background var(--transition);
}

.main-nav a::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 4px;
  height: 2px;
  background: var(--gradient-accent);
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}

.main-nav a:hover {
  color: var(--text);
  background: var(--surface);
}

.main-nav a:hover::after {
  transform: scaleX(1);
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px 0;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  list-style: none;
  font-size: 0.85rem;
  color: var(--text-dim);
}

.breadcrumb li + li::before {
  content: "›";
  margin-right: 8px;
  color: var(--text-dim);
}

.breadcrumb a {
  color: var(--text-muted);
}

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

.breadcrumb [aria-current="page"] {
  color: var(--text);
  font-weight: 500;
}

/* ===== Main layout ===== */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 64px;
}

main > section {
  padding: 48px 0;
  border-bottom: 1px solid var(--border);
}

main > section:last-child {
  border-bottom: none;
}

/* ===== Typography ===== */
h1 {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 20px;
}

h2 {
  font-size: clamp(1.4rem, 2.6vw, 1.9rem);
  line-height: 1.3;
  font-weight: 700;
  margin-bottom: 20px;
  position: relative;
  padding-left: 18px;
}

h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.2em;
  bottom: 0.2em;
  width: 5px;
  border-radius: 3px;
  background: var(--gradient-accent);
}

h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 28px 0 12px;
  color: var(--text);
}

h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 20px 0 8px;
  color: var(--accent);
}

p {
  margin-bottom: 14px;
  color: var(--text-muted);
}

strong {
  color: var(--text);
  font-weight: 600;
}

ul,
ol {
  margin: 0 0 16px 1.4em;
  color: var(--text-muted);
}

li {
  margin-bottom: 8px;
}

li::marker {
  color: var(--accent);
}

blockquote {
  margin: 20px 0;
  padding: 20px 24px;
  background: var(--gradient-card);
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  transition: transform var(--transition), box-shadow var(--transition);
}

blockquote:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow);
}

blockquote p {
  margin: 0;
  font-style: italic;
  color: var(--text);
}

/* ===== Hero ===== */
.hero {
  position: relative;
  margin: 32px 0 0;
  padding: 56px 40px !important;
  border-radius: var(--radius-lg);
  background: var(--gradient-hero);
  overflow: hidden;
  border: 1px solid var(--glass-border) !important;
  box-shadow: var(--shadow);
  animation: heroFadeIn 0.8s ease both;
}

.hero::before,
.hero::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.45;
  pointer-events: none;
}

.hero::before {
  width: 320px;
  height: 320px;
  background: var(--accent);
  top: -120px;
  right: -80px;
  animation: float 8s ease-in-out infinite;
}

.hero::after {
  width: 260px;
  height: 260px;
  background: var(--accent-2);
  bottom: -100px;
  left: -60px;
  animation: float 10s ease-in-out infinite reverse;
}

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

.hero h1 {
  background: linear-gradient(120deg, var(--text) 30%, var(--accent) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-lead {
  font-size: 1.02rem;
  color: var(--text-muted);
  max-width: 900px;
}

.hero-question {
  margin-top: 20px;
  padding: 16px 20px;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  color: var(--text-muted);
}

.hero-question strong {
  color: var(--accent);
}

/* ===== Cards (generic section enhancement) ===== */
#about,
#concept,
#products,
#solutions,
#howto,
#knowledge {
  scroll-margin-top: 96px;
}

#cases,
#articles,
#faq,
#contact,
#sitemap,
#links,
#legal,
#page-meta {
  scroll-margin-top: 96px;
}

/* ===== Article cards ===== */
#articles article {
  position: relative;
  margin-bottom: 20px;
  padding: 24px 28px;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

#articles article::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  background: var(--gradient-card);
  opacity: 0;
  transition: opacity var(--transition);
  pointer-events: none;
}

#articles article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(233, 69, 96, 0.35);
}

#articles article:hover::before {
  opacity: 1;
}

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

#articles article h3 {
  margin-top: 0;
  margin-bottom: 8px;
  font-size: 1.15rem;
  color: var(--text);
  transition: color var(--transition);
}

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

.meta {
  font-size: 0.82rem;
  color: var(--text-dim);
  margin-bottom: 10px;
  letter-spacing: 0.01em;
}

#articles article a {
  display: inline-block;
  margin-top: 6px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
  position: relative;
}

#articles article a::after {
  content: "→";
  margin-left: 6px;
  transition: margin-left var(--transition);
}

#articles article a:hover::after {
  margin-left: 12px;
}

/* ===== FAQ ===== */
#faq details {
  margin-bottom: 12px;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition);
}

#faq details:hover {
  border-color: rgba(233, 69, 96, 0.3);
}

#faq details[open] {
  box-shadow: var(--shadow);
  border-color: rgba(233, 69, 96, 0.4);
}

#faq summary {
  padding: 18px 24px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  position: relative;
  padding-right: 52px;
  transition: color var(--transition);
  user-select: none;
}

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

#faq summary::after {
  content: "+";
  position: absolute;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.4rem;
  font-weight: 300;
  color: var(--accent);
  transition: transform var(--transition);
  line-height: 1;
}

#faq details[open] summary::after {
  content: "−";
  transform: translateY(-50%) rotate(180deg);
}

#faq summary:hover {
  color: var(--accent);
}

#faq details p {
  padding: 0 24px 20px;
  margin: 0;
  animation: fadeIn 0.35s ease both;
}

/* ===== Contact / info lists ===== */
#contact ul,
#sitemap ul,
#links ul,
#page-meta ul {
  list-style: none;
  margin-left: 0;
  display: grid;
  gap: 10px;
}

#contact ul li,
#page-meta ul li {
  padding: 12px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  transition: transform var(--transition), border-color var(--transition), background var(--transition);
}

#contact ul li:hover,
#page-meta ul li:hover {
  transform: translateX(4px);
  border-color: rgba(233, 69, 96, 0.35);
  background: var(--gradient-card);
}

#sitemap ul,
#links ul {
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}

#sitemap ul li,
#links ul li {
  margin: 0;
}

#sitemap a,
#links a {
  display: block;
  padding: 12px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-weight: 500;
  transition: transform var(--transition), border-color var(--transition), color var(--transition), background var(--transition);
}

#sitemap a:hover,
#links a:hover {
  transform: translateY(-3px);
  border-color: rgba(233, 69, 96, 0.4);
  color: var(--text);
  background: var(--gradient-card);
  box-shadow: var(--shadow);
}

/* ===== Scroll animations ===== */
main > section {
  animation: fadeUp 0.7s ease both;
}

@supports (animation-timeline: view()) {
  main > section {
    animation: fadeUp linear both;
    animation-timeline: view();
    animation-range: entry 0% entry 40%;
  }
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(28px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes heroFadeIn {
  from {
    opacity: 0;
    transform: scale(0.98);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes float {
  0%,
  100% {
    transform: translate(0, 0);
  }
  50% {
    transform: translate(20px, -20px);
  }
}

/* ===== Footer ===== */
.site-footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 40px 24px;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.88rem;
}

.site-footer p {
  margin-bottom: 8px;
  color: var(--text-dim);
}

.site-footer nav {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 24px;
}

.site-footer nav a {
  color: var(--text-muted);
  font-size: 0.88rem;
  position: relative;
  transition: color var(--transition);
}

.site-footer nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -3px;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transition: transform var(--transition);
}

.site-footer nav a:hover {
  color: var(--accent);
}

.site-footer nav a:hover::after {
  transform: scaleX(1);
}

/* ===== Responsive ===== */
@media (max-width: 960px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .main-nav {
    width: 100%;
  }

  .main-nav ul {
    gap: 2px;
  }

  .main-nav a {
    padding: 6px 10px;
    font-size: 0.85rem;
  }

  .hero {
    padding: 40px 28px !important;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 15px;
  }

  main {
    padding: 0 16px 48px;
  }

  .header-inner {
    padding: 10px 16px;
  }

  .breadcrumb {
    padding: 12px 16px 0;
  }

  .main-nav ul {
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: 4px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

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

  .main-nav a {
    white-space: nowrap;
    font-size: 0.82rem;
  }

  .hero {
    margin-top: 20px;
    padding: 32px 20px !important;
    border-radius: var(--radius);
  }

  .hero::before {
    width: 200px;
    height: 200px;
    top: -80px;
    right: -60px;
  }

  .hero::after {
    width: 160px;
    height: 160px;
    bottom: -60px;
    left: -40px;
  }

  main > section {
    padding: 32px 0;
  }

  h2 {
    padding-left: 14px;
  }

  h2::before {
    width: 4px;
  }

  #articles article {
    padding: 20px;
  }

  #faq summary {
    padding: 16px 18px;
    padding-right: 46px;
    font-size: 0.95rem;
  }

  #faq summary::after {
    right: 18px;
  }

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

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

  blockquote {
    padding: 16px 18px;
  }

  .site-footer {
    padding: 32px 16px;
  }
}

/* ===== Print ===== */
@media print {
  .site-header,
  .breadcrumb,
  .skip-link,
  .site-footer {
    display: none;
  }

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

  main > section {
    animation: none;
    border-bottom: 1px solid #ccc;
  }

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