:root {
  --color-primary: #1a3a5c;
  --color-primary-light: #2d5a87;
  --color-accent: #f2b705;
  --color-accent-soft: #ffd54a;
  --color-bg: #f4f7fa;
  --color-surface: #ffffff;
  --color-surface-glass: rgba(255, 255, 255, 0.72);
  --color-text: #1c2b3a;
  --color-text-soft: #4a5c6e;
  --color-muted: #7a8a9a;
  --color-border: rgba(26, 58, 92, 0.12);
  --color-shadow: rgba(26, 58, 92, 0.12);
  --gradient-banner: linear-gradient(135deg, #1a3a5c 0%, #2d5a87 48%, #3f7fb8 100%);
  --gradient-accent: linear-gradient(135deg, #f2b705 0%, #ffd54a 100%);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-pill: 999px;
  --space-xs: 0.5rem;
  --space-sm: 0.875rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --font-base: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --transition: 0.28s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 1180px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0e1620;
    --color-surface: #16212e;
    --color-surface-glass: rgba(22, 33, 46, 0.72);
    --color-text: #e6edf4;
    --color-text-soft: #b3c1cf;
    --color-muted: #8496a8;
    --color-border: rgba(255, 255, 255, 0.1);
    --color-shadow: rgba(0, 0, 0, 0.45);
    --gradient-banner: linear-gradient(135deg, #0b1520 0%, #16324c 50%, #1f4a70 100%);
  }
}

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

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

body {
  margin: 0;
  font-family: var(--font-base);
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text);
  background: var(--color-bg);
  background-image: radial-gradient(circle at 12% 0%, rgba(45, 90, 135, 0.1), transparent 45%),
    radial-gradient(circle at 88% 8%, rgba(242, 183, 5, 0.08), transparent 40%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

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

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

h1,
h2,
h3 {
  line-height: 1.35;
  font-weight: 700;
  color: var(--color-text);
  scroll-margin-top: 96px;
}

h1 {
  font-size: clamp(1.6rem, 4vw, 2.6rem);
  letter-spacing: 0.01em;
}

h2 {
  font-size: clamp(1.3rem, 2.6vw, 1.85rem);
  position: relative;
  padding-left: 16px;
  margin-top: 0;
}

h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.18em;
  bottom: 0.18em;
  width: 5px;
  border-radius: var(--radius-pill);
  background: var(--gradient-accent);
}

h3 {
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
  margin-bottom: 0.5em;
}

p {
  margin: 0 0 1em;
  color: var(--color-text-soft);
}

ul,
ol {
  padding-left: 1.4em;
  color: var(--color-text-soft);
}

li {
  margin-bottom: 0.35em;
}

blockquote {
  margin: 1rem 0;
  padding: 1rem 1.25rem;
  border-left: 4px solid var(--color-accent);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--color-surface-glass);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 4px 18px var(--color-shadow);
}

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

time {
  display: inline-block;
  font-size: 0.82rem;
  color: var(--color-muted);
  letter-spacing: 0.02em;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ============ Header ============ */
#site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface-glass);
  backdrop-filter: blur(16px) saturate(1.6);
  -webkit-backdrop-filter: blur(16px) saturate(1.6);
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 6px 24px rgba(26, 58, 92, 0.06);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.75rem var(--space-md);
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--color-text);
  font-weight: 800;
  font-size: 1.1rem;
  letter-spacing: 0.02em;
  flex-shrink: 0;
}

.brand svg {
  transition: transform var(--transition);
  filter: drop-shadow(0 3px 8px rgba(242, 183, 5, 0.35));
}

.brand:hover svg {
  transform: rotate(-12deg) scale(1.06);
}

.brand-name {
  background: var(--gradient-banner);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

@media (prefers-color-scheme: dark) {
  .brand-name {
    background: linear-gradient(135deg, #e6edf4, #ffd54a);
    -webkit-background-clip: text;
    background-clip: text;
  }
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  display: block;
  padding: 0.4rem 0.7rem;
  border-radius: var(--radius-pill);
  font-size: 0.9rem;
  color: var(--color-text-soft);
  transition: background var(--transition), color var(--transition), transform var(--transition);
}

.nav-list a:hover,
.nav-list a:focus-visible {
  background: rgba(45, 90, 135, 0.12);
  color: var(--color-primary-light);
  transform: translateY(-1px);
}

.site-search {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-left: auto;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  padding: 0.25rem 0.25rem 0.25rem 0.9rem;
  box-shadow: inset 0 1px 3px rgba(26, 58, 92, 0.05);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.site-search:focus-within {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(242, 183, 5, 0.2);
}

.site-search input {
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--color-text);
  font-family: inherit;
  font-size: 0.9rem;
  width: 200px;
  padding: 0.35rem 0;
}

.site-search input::placeholder {
  color: var(--color-muted);
}

.site-search button {
  border: 0;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  color: #1a2b3a;
  background: var(--gradient-accent);
  padding: 0.45rem 1rem;
  border-radius: var(--radius-pill);
  transition: transform var(--transition), box-shadow var(--transition), filter var(--transition);
}

.site-search button:hover,
.site-search button:focus-visible {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(242, 183, 5, 0.4);
  filter: brightness(1.05);
}

/* ============ Layout ============ */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md) var(--space-xl);
}

main > section {
  margin-top: var(--space-lg);
  padding: var(--space-lg) var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: 0 10px 34px var(--color-shadow);
  animation: fadeUp 0.7s cubic-bezier(0.22, 0.61, 0.36, 1) both;
}

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

@supports (animation-timeline: view()) {
  main > section {
    animation: fadeUp 0.7s linear both;
    animation-timeline: view();
    animation-range: entry 0% entry 40%;
  }
}

/* ============ Breadcrumb ============ */
.breadcrumb {
  margin-top: var(--space-md);
  font-size: 0.85rem;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  list-style: none;
  margin: 0;
  padding: 0;
  color: var(--color-muted);
}

.breadcrumb li + li::before {
  content: "/";
  margin-right: 0.4rem;
  color: var(--color-border);
}

/* ============ Banner ============ */
#banner {
  position: relative;
  overflow: hidden;
  background: var(--gradient-banner);
  border: 0;
  color: #eaf2f9;
  padding: var(--space-xl) var(--space-md);
  box-shadow: 0 20px 50px rgba(26, 58, 92, 0.3);
}

#banner::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 85% 15%, rgba(242, 183, 5, 0.28), transparent 45%),
    radial-gradient(circle at 10% 90%, rgba(63, 127, 184, 0.35), transparent 50%);
  pointer-events: none;
}

#banner h1,
#banner .lead,
#banner .banner-carousel {
  position: relative;
  z-index: 1;
}

#banner h1 {
  color: #ffffff;
  padding-left: 0;
  margin-bottom: 0.6em;
  text-shadow: 0 2px 18px rgba(0, 0, 0, 0.25);
}

#banner h1::before {
  display: none;
}

#banner .lead {
  max-width: 860px;
  color: rgba(234, 242, 249, 0.88);
  font-size: 1.02rem;
}

.banner-carousel {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

.banner-slide {
  padding: 1.4rem;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.22);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: transform var(--transition), background var(--transition), box-shadow var(--transition);
}

.banner-slide:hover {
  transform: translateY(-6px);
  background: rgba(255, 255, 255, 0.18);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.25);
}

.banner-slide h2 {
  color: #ffffff;
  font-size: 1.15rem;
  padding-left: 0;
  margin-bottom: 0.4em;
}

.banner-slide h2::before {
  display: none;
}

.banner-slide p {
  color: rgba(234, 242, 249, 0.82);
  font-size: 0.92rem;
  margin-bottom: 0.9em;
}

.banner-slide a {
  display: inline-block;
  font-size: 0.88rem;
  font-weight: 700;
  color: #1a2b3a;
  background: var(--gradient-accent);
  padding: 0.45rem 1.1rem;
  border-radius: var(--radius-pill);
  transition: transform var(--transition), box-shadow var(--transition);
}

.banner-slide a:hover,
.banner-slide a:focus-visible {
  color: #1a2b3a;
  transform: translateX(4px);
  box-shadow: 0 8px 20px rgba(242, 183, 5, 0.45);
}

/* ============ Timeline ============ */
.timeline {
  list-style: none;
  padding: 0;
  margin: 1rem 0 1.5rem;
  position: relative;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--color-accent), rgba(45, 90, 135, 0.4));
  border-radius: var(--radius-pill);
}

.timeline li {
  position: relative;
  padding-left: 2rem;
  margin-bottom: 0.9rem;
  color: var(--color-text-soft);
  transition: transform var(--transition), color var(--transition);
}

.timeline li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.55em;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-surface);
  border: 3px solid var(--color-accent);
  box-shadow: 0 0 0 3px rgba(242, 183, 5, 0.18);
}

.timeline li:hover {
  transform: translateX(4px);
  color: var(--color-text);
}

.timeline strong {
  color: var(--color-primary-light);
}

/* ============ Lists inside sections ============ */
#products > ul,
#howto ul {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}

#products > ul li,
#howto ul li {
  position: relative;
  padding: 0.75rem 1rem 0.75rem 2.4rem;
  background: var(--color-bg);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

#products > ul li::before,
#howto ul li::before {
  content: "✦";
  position: absolute;
  left: 0.9rem;
  top: 0.72rem;
  color: var(--color-accent);
  font-size: 0.95rem;
}

#products > ul li:hover,
#howto ul li:hover {
  transform: translateX(4px);
  border-color: rgba(242, 183, 5, 0.5);
  box-shadow: 0 6px 18px var(--color-shadow);
}

#howto ol {
  counter-reset: step;
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.7rem;
}

#howto ol li {
  counter-increment: step;
  position: relative;
  padding: 0.9rem 1rem 0.9rem 3.2rem;
  background: var(--color-bg);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  transition: transform var(--transition), box-shadow var(--transition);
}

#howto ol li::before {
  content: counter(step);
  position: absolute;
  left: 0.8rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1.7rem;
  height: 1.7rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  font-size: 0.82rem;
  font-weight: 700;
  color: #1a2b3a;
  background: var(--gradient-accent);
}

#howto ol li:hover {
  transform: translateX(4px);
  box-shadow: 0 6px 18px var(--color-shadow);
}

/* ============ News ============ */
.news-list {
  list-style: none;
  padding: 0;
  display: grid;
  gap: var(--space-md);
}

.news-list li {
  padding: 1.1rem 1.3rem;
  border-radius: var(--radius-md);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-accent);
  transition: transform var(--transition), box-shadow var(--transition);
}

.news-list li:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 28px var(--color-shadow);
}

.news-list h3 {
  margin: 0.3rem 0 0.4rem;
}

.news-list p {
  margin: 0;
  font-size: 0.94rem;
}

/* ============ Articles ============ */
#articles {
  display: grid;
  gap: var(--space-md);
}

#articles > h2 {
  grid-column: 1 / -1;
}

#articles article {
  padding: 1.3rem;
  border-radius: var(--radius-md);
  background: var(--color-surface-glass);
  border: 1px solid var(--color-border);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

#articles article:hover {
  transform: translateY(-5px);
  border-color: rgba(242, 183, 5, 0.45);
  box-shadow: 0 16px 36px var(--color-shadow);
}

#articles article h3 {
  margin: 0 0 0.35rem;
  font-size: 1.05rem;
}

#articles article h3 a {
  color: var(--color-text);
}

#articles article h3 a:hover {
  color: var(--color-primary-light);
}

#articles article p {
  font-size: 0.92rem;
}

#articles article > a:last-child {
  display: inline-block;
  margin-top: 0.3rem;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--color-primary-light);
  border-bottom: 2px solid transparent;
  transition: border-color var(--transition), color var(--transition);
}

#articles article > a:last-child:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

/* ============ FAQ ============ */
#faq details {
  margin-bottom: 0.7rem;
  border-radius: var(--radius-md);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  overflow: hidden;
  transition: box-shadow var(--transition), border-color var(--transition);
}

#faq details[open] {
  border-color: rgba(242, 183, 5, 0.5);
  box-shadow: 0 8px 24px var(--color-shadow);
}

#faq summary {
  cursor: pointer;
  list-style: none;
  position: relative;
  padding: 1rem 3rem 1rem 1.2rem;
  font-weight: 600;
  color: var(--color-text);
  transition: background var(--transition), color var(--transition);
}

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

#faq summary::after {
  content: "+";
  position: absolute;
  right: 1.1rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1.5rem;
  height: 1.5rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  font-size: 1.1rem;
  font-weight: 700;
  color: #1a2b3a;
  background: var(--gradient-accent);
  transition: transform var(--transition);
}

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

#faq summary:hover {
  background: rgba(45, 90, 135, 0.06);
  color: var(--color-primary-light);
}

#faq details p {
  margin: 0;
  padding: 0 1.2rem 1.1rem;
  font-size: 0.94rem;
  animation: fadeUp 0.4s ease both;
}

/* ============ Contact / Address ============ */
address {
  font-style: normal;
  display: grid;
  gap: 0.4rem;
  padding: 1.2rem 1.4rem;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(45, 90, 135, 0.08), rgba(242, 183, 5, 0.08));
  border: 1px solid var(--color-border);
}

address p {
  margin: 0;
}

/* ============ Sitemap / Links ============ */
#sitemap ul,
#links ul {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

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

#sitemap a,
#links a {
  display: inline-block;
  padding: 0.4rem 0.95rem;
  font-size: 0.88rem;
  border-radius: var(--radius-pill);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  color: var(--color-text-soft);
  transition: background var(--transition), color var(--transition), transform var(--transition), border-color var(--transition);
}

#sitemap a:hover,
#links a:hover {
  background: var(--color-primary);
  color: #ffffff;
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

/* ============ Footer ============ */
footer {
  margin-top: var(--space-xl);
  padding: var(--space-xl) var(--space-md) var(--space-lg);
  background: var(--gradient-banner);
  color: rgba(234, 242, 249, 0.85);
}

footer > section,
footer > .copyright {
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
}

footer h2 {
  color: #ffffff;
  font-size: 1.15rem;
  padding-left: 14px;
}

footer h2::before {
  background: var(--gradient-accent);
}

footer h3 {
  color: var(--color-accent-soft);
  font-size: 0.98rem;
  margin-top: 1rem;
}

footer p {
  color: rgba(234, 242, 249, 0.78);
  font-size: 0.92rem;
}

footer a {
  color: var(--color-accent-soft);
}

footer a:hover {
  color: #ffffff;
}

footer > section {
  padding-bottom: var(--space-md);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

footer > section + section {
  padding-top: var(--space-md);
}

footer .copyright {
  padding-top: var(--space-md);
  text-align: center;
  font-size: 0.85rem;
  color: rgba(234, 242, 249, 0.6);
}

/* ============ Back to top ============ */
#back-to-top {
  position: fixed;
  right: 1.2rem;
  bottom: 1.2rem;
  z-index: 120;
  border: 0;
  cursor: pointer;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 700;
  color: #1a2b3a;
  background: var(--gradient-accent);
  padding: 0.7rem 1.1rem;
  border-radius: var(--radius-pill);
  box-shadow: 0 10px 26px rgba(242, 183, 5, 0.4);
  transition: transform var(--transition), box-shadow var(--transition), filter var(--transition);
}

#back-to-top:hover,
#back-to-top:focus-visible {
  transform: translateY(-4px);
  box-shadow: 0 16px 34px rgba(242, 183, 5, 0.55);
  filter: brightness(1.06);
}

#back-to-top:active {
  transform: translateY(-1px) scale(0.97);
}

/* ============ Focus states ============ */
a:focus-visible,
button:focus-visible,
input:focus-visible,
summary:focus-visible {
  outline: 3px solid rgba(242, 183, 5, 0.65);
  outline-offset: 2px;
}

/* ============ Responsive ============ */
@media (min-width: 720px) {
  #articles {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  #articles {
    grid-template-columns: repeat(3, 1fr);
  }

  main > section {
    padding: var(--space-lg) var(--space-lg);
  }
}

@media (max-width: 860px) {
  .header-inner {
    gap: var(--space-sm);
  }

  .nav-list {
    order: 3;
    width: 100%;
    justify-content: flex-start;
    padding-top: 0.4rem;
    border-top: 1px dashed var(--color-border);
  }

  .site-search {
    margin-left: auto;
  }

  .site-search input {
    width: 130px;
  }
}

@media (max-width: 600px) {
  body {
    font-size: 15px;
  }

  .header-inner {
    padding: 0.6rem var(--space-sm);
  }

  .brand-name {
    font-size: 1rem;
  }

  .nav-list {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    gap: 0.15rem;
  }

  .nav-list::-webkit-scrollbar {
    display: none;
  }

  .nav-list a {
    white-space: nowrap;
    font-size: 0.84rem;
    padding: 0.35rem 0.6rem;
  }

  .site-search {
    flex: 1 1 100%;
    order: 2;
  }

  .site-search input {
    width: 100%;
  }

  main {
    padding: 0 var(--space-sm) var(--space-lg);
  }

  main > section {
    margin-top: var(--space-md);
    padding: var(--space-md) var(--space-sm);
    border-radius: var(--radius-md);
  }

  #banner {
    padding: var(--space-lg) var(--space-sm);
    border-radius: var(--radius-md);
  }

  .banner-carousel {
    grid-template-columns: 1fr;
    gap: var(--space-sm);
  }

  #back-to-top {
    right: 0.8rem;
    bottom: 0.8rem;
    padding: 0.6rem 0.95rem;
    font-size: 0.8rem;
  }

  footer {
    padding: var(--space-lg) var(--space-sm) var(--space-md);
  }
}

@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;
  }
}

@media print {
  #site-header,
  #back-to-top,
  .banner-carousel,
  footer {
    display: none;
  }

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

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