:root {
  --bg: #f4f6fb;
  --bg-soft: #eef2f9;
  --surface: rgba(255, 255, 255, 0.72);
  --surface-solid: #ffffff;
  --surface-glass: rgba(255, 255, 255, 0.55);
  --border: rgba(15, 23, 42, 0.08);
  --border-strong: rgba(15, 23, 42, 0.14);
  --text: #0f172a;
  --text-soft: #475569;
  --text-muted: #64748b;
  --primary: #2563eb;
  --primary-deep: #1e3a8a;
  --primary-soft: rgba(37, 99, 235, 0.1);
  --accent: #f59e0b;
  --accent-soft: rgba(245, 158, 11, 0.14);
  --violet: #7c3aed;
  --cyan: #06b6d4;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 20px 48px rgba(15, 23, 42, 0.12);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 22px;
  --radius-xl: 28px;
  --header-h: 68px;
  --max-w: 1180px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --grad-hero: linear-gradient(135deg, #1e3a8a 0%, #2563eb 42%, #7c3aed 100%);
  --grad-accent: linear-gradient(120deg, #f59e0b, #f97316);
  --grad-glass: linear-gradient(135deg, rgba(255, 255, 255, 0.75), rgba(255, 255, 255, 0.35));
}

html[data-theme="dark"] {
  --bg: #070c18;
  --bg-soft: #0b1222;
  --surface: rgba(20, 30, 52, 0.68);
  --surface-solid: #111a2e;
  --surface-glass: rgba(17, 26, 46, 0.55);
  --border: rgba(148, 163, 184, 0.14);
  --border-strong: rgba(148, 163, 184, 0.26);
  --text: #e8eefb;
  --text-soft: #b6c2d9;
  --text-muted: #8b9bb8;
  --primary: #60a5fa;
  --primary-deep: #1d4ed8;
  --primary-soft: rgba(96, 165, 250, 0.14);
  --accent: #fbbf24;
  --accent-soft: rgba(251, 191, 36, 0.16);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 10px 28px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 24px 56px rgba(0, 0, 0, 0.55);
  --grad-hero: linear-gradient(135deg, #0b1222 0%, #14264d 45%, #3b1f7a 100%);
  --grad-glass: linear-gradient(135deg, rgba(30, 42, 70, 0.7), rgba(17, 26, 46, 0.4));
}

@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) {
    --bg: #070c18;
    --bg-soft: #0b1222;
    --surface: rgba(20, 30, 52, 0.68);
    --surface-solid: #111a2e;
    --surface-glass: rgba(17, 26, 46, 0.55);
    --border: rgba(148, 163, 184, 0.14);
    --border-strong: rgba(148, 163, 184, 0.26);
    --text: #e8eefb;
    --text-soft: #b6c2d9;
    --text-muted: #8b9bb8;
    --primary: #60a5fa;
    --primary-deep: #1d4ed8;
    --primary-soft: rgba(96, 165, 250, 0.14);
    --accent: #fbbf24;
    --accent-soft: rgba(251, 191, 36, 0.16);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 10px 28px rgba(0, 0, 0, 0.45);
    --shadow-lg: 0 24px 56px rgba(0, 0, 0, 0.55);
    --grad-hero: linear-gradient(135deg, #0b1222 0%, #14264d 45%, #3b1f7a 100%);
    --grad-glass: linear-gradient(135deg, rgba(30, 42, 70, 0.7), rgba(17, 26, 46, 0.4));
  }
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  background-image:
    radial-gradient(1200px 600px at 100% -10%, rgba(124, 58, 237, 0.12), transparent 60%),
    radial-gradient(900px 500px at -10% 5%, rgba(37, 99, 235, 0.12), transparent 55%);
  background-attachment: fixed;
  transition: background-color 0.35s var(--ease), color 0.35s var(--ease);
  overflow-x: hidden;
}

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

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s var(--ease), opacity 0.2s var(--ease);
}

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

h1, h2, h3, h4 {
  line-height: 1.3;
  color: var(--text);
  letter-spacing: -0.01em;
  scroll-margin-top: calc(var(--header-h) + 20px);
}

h1 {
  font-size: clamp(1.6rem, 3.2vw, 2.5rem);
  font-weight: 800;
  margin: 0 0 0.6em;
}

h2 {
  font-size: clamp(1.35rem, 2.4vw, 1.9rem);
  font-weight: 750;
  margin: 0 0 0.7em;
  position: relative;
  padding-left: 16px;
}

h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.18em;
  bottom: 0.18em;
  width: 5px;
  border-radius: 6px;
  background: var(--grad-accent);
}

h3 {
  font-size: clamp(1.08rem, 1.6vw, 1.28rem);
  font-weight: 700;
  margin: 1.6em 0 0.55em;
  color: var(--text);
}

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

ul, ol {
  color: var(--text-soft);
  padding-left: 1.35em;
}

li {
  margin-bottom: 0.4em;
}

blockquote {
  margin: 1.2em 0;
  padding: 16px 20px;
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: var(--surface-glass);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--border);
  border-left-width: 4px;
  box-shadow: var(--shadow-sm);
}

blockquote p {
  margin: 0 0 0.4em;
  color: var(--text);
  font-style: italic;
}

blockquote cite {
  font-style: normal;
  font-size: 0.88rem;
  color: var(--text-muted);
}

time {
  font-size: 0.86rem;
  color: var(--text-muted);
}

address {
  font-style: normal;
}

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

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

.visually-hidden {
  position: absolute !important;
  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(--surface);
  backdrop-filter: blur(18px) saturate(160%);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  transition: background 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 20px;
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  color: var(--text);
  font-weight: 800;
  font-size: 1.08rem;
  letter-spacing: 0.01em;
}

.brand:hover {
  color: var(--text);
}

.brand svg {
  border-radius: 11px;
  box-shadow: 0 4px 14px rgba(30, 58, 138, 0.35);
  transition: transform 0.45s var(--ease);
}

.brand:hover svg {
  transform: rotate(-6deg) scale(1.06);
}

.brand-name {
  background: linear-gradient(100deg, var(--primary), var(--violet));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

#site-header nav[aria-label="主导航"] {
  flex: 1 1 auto;
  min-width: 0;
}

.main-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.main-nav li {
  margin: 0;
}

.main-nav a {
  display: inline-block;
  padding: 7px 11px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-soft);
  border-radius: 999px;
  transition: color 0.2s var(--ease), background 0.2s var(--ease), transform 0.2s var(--ease);
}

.main-nav a:hover {
  color: var(--primary);
  background: var(--primary-soft);
  transform: translateY(-1px);
}

.site-search {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.site-search input {
  width: 190px;
  padding: 8px 14px;
  font-size: 0.88rem;
  font-family: inherit;
  color: var(--text);
  background: var(--surface-glass);
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: width 0.3s var(--ease), border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

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

.site-search input:focus {
  width: 230px;
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px var(--primary-soft);
}

.site-search button,
#theme-toggle,
#menu-toggle {
  font-family: inherit;
  font-size: 0.86rem;
  font-weight: 600;
  color: #fff;
  cursor: pointer;
  border: none;
  border-radius: 999px;
  padding: 8px 15px;
  background: var(--grad-hero);
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.28);
  transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease), filter 0.2s var(--ease);
}

.site-search button:hover,
#theme-toggle:hover,
#menu-toggle:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.36);
  filter: brightness(1.06);
}

.site-search button:active,
#theme-toggle:active,
#menu-toggle:active {
  transform: translateY(0) scale(0.97);
}

#theme-toggle {
  background: var(--surface-glass);
  color: var(--text);
  border: 1px solid var(--border-strong);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

#theme-toggle:hover {
  color: var(--primary);
  border-color: var(--primary);
  box-shadow: 0 6px 18px var(--primary-soft);
}

#menu-toggle {
  display: none;
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid rgba(245, 158, 11, 0.4);
  box-shadow: none;
}

#menu-toggle:hover {
  color: #fff;
  background: var(--grad-accent);
}

#mobile-menu {
  border-top: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  animation: menuDrop 0.28s var(--ease);
}

#mobile-menu ul {
  list-style: none;
  margin: 0;
  padding: 10px 20px 16px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 4px;
}

#mobile-menu a {
  display: block;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  color: var(--text-soft);
  font-size: 0.92rem;
}

#mobile-menu a:hover {
  background: var(--primary-soft);
  color: var(--primary);
}

@keyframes menuDrop {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============ Main layout ============ */
main {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 20px 40px;
}

main > section {
  margin: 34px 0;
  padding: 30px clamp(18px, 3vw, 38px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  box-shadow: var(--shadow-md);
  transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease), border-color 0.3s var(--ease);
}

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

/* ============ Breadcrumb ============ */
.breadcrumb {
  margin: 20px 0 0;
  font-size: 0.86rem;
}

.breadcrumb ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  margin: 0;
  padding: 0;
}

.breadcrumb li {
  margin: 0;
  color: var(--text-muted);
}

.breadcrumb li + li::before {
  content: "›";
  margin-right: 6px;
  color: var(--text-muted);
  opacity: 0.6;
}

.breadcrumb a {
  color: var(--text-soft);
  padding: 3px 8px;
  border-radius: 999px;
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}

.breadcrumb a:hover {
  color: var(--primary);
  background: var(--primary-soft);
}

.breadcrumb [aria-current="page"] {
  color: var(--text);
  font-weight: 600;
}

/* ============ Hero ============ */
#hero {
  position: relative;
  overflow: hidden;
  margin-top: 22px !important;
  padding: clamp(28px, 5vw, 56px) clamp(20px, 4vw, 48px) !important;
  background: var(--grad-hero) !important;
  border: none !important;
  border-radius: var(--radius-xl) !important;
  color: #fff;
  box-shadow: 0 24px 60px rgba(30, 58, 138, 0.35) !important;
  isolation: isolate;
}

#hero::before {
  content: "";
  position: absolute;
  inset: -40% -10% auto auto;
  width: 520px;
  height: 520px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(251, 191, 36, 0.32), transparent 65%);
  filter: blur(10px);
  z-index: -1;
  animation: floatBlob 14s ease-in-out infinite alternate;
}

#hero::after {
  content: "";
  position: absolute;
  inset: auto auto -45% -12%;
  width: 480px;
  height: 480px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(6, 182, 212, 0.3), transparent 65%);
  filter: blur(12px);
  z-index: -1;
  animation: floatBlob 18s ease-in-out infinite alternate-reverse;
}

@keyframes floatBlob {
  from { transform: translate3d(0, 0, 0) scale(1); }
  to { transform: translate3d(-30px, 24px, 0) scale(1.12); }
}

#hero h1 {
  color: #fff;
  text-shadow: 0 2px 24px rgba(0, 0, 0, 0.25);
  max-width: 20ch;
}

#hero .hero-lead {
  color: rgba(255, 255, 255, 0.88);
  max-width: 68ch;
  font-size: 1.02rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin: 26px 0 34px;
}

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 28px;
  font-size: 0.96rem;
  font-weight: 700;
  border-radius: 999px;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), background 0.25s var(--ease), color 0.25s var(--ease);
}

.btn-primary {
  color: #1e293b;
  background: var(--grad-accent);
  box-shadow: 0 10px 26px rgba(245, 158, 11, 0.42);
}

.btn-primary:hover {
  color: #1e293b;
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 16px 34px rgba(245, 158, 11, 0.5);
}

.btn-secondary {
  color: #fff;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.4);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.26);
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.25);
}

.hero-figure {
  margin: 0 0 30px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.22);
  background: rgba(15, 23, 42, 0.55);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 18px 44px rgba(0, 0, 0, 0.35);
  transition: transform 0.5s var(--ease), box-shadow 0.5s var(--ease);
}

.hero-figure:hover {
  transform: translateY(-4px) scale(1.008);
  box-shadow: 0 26px 60px rgba(0, 0, 0, 0.45);
}

.hero-figure svg {
  width: 100%;
  height: auto;
}

.hero-figure figcaption {
  padding: 12px 18px;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.75);
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  text-align: center;
}

.hero-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
}

.hero-stats li {
  margin: 0;
  padding: 18px 12px;
  text-align: center;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: transform 0.3s var(--ease), background 0.3s var(--ease);
}

.hero-stats li:hover {
  transform: translateY(-4px);
  background: rgba(255, 255, 255, 0.18);
}

.hero-stats strong {
  display: block;
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 800;
  color: var(--accent);
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}

.hero-stats span {
  display: block;
  margin-top: 4px;
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.82);
  letter-spacing: 0.02em;
}

/* ============ Articles & cards ============ */
#news article,
#articles article,
#article-detail article {
  position: relative;
  padding: 22px clamp(16px, 2.4vw, 26px);
  margin: 0 0 18px;
  background: var(--surface-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--shadow-sm);
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), border-color 0.3s var(--ease);
}

#news article::before,
#articles article::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  bottom: 18px;
  width: 3px;
  border-radius: 3px;
  background: var(--grad-accent);
  opacity: 0;
  transition: opacity 0.3s var(--ease);
}

#news article:hover,
#articles article:hover,
#article-detail article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--border-strong);
}

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

#news article h3,
#articles article h3,
#article-detail article h3 {
  margin-top: 0;
}

#articles article h3 a,
#articles article > a {
  font-weight: 600;
}

#articles article > a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 4px;
  padding: 7px 16px;
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--primary);
  background: var(--primary-soft);
  border-radius: 999px;
  transition: background 0.25s var(--ease), color 0.25s var(--ease), transform 0.25s var(--ease);
}

#articles article > a::after {
  content: "→";
  transition: transform 0.25s var(--ease);
}

#articles article > a:hover {
  color: #fff;
  background: var(--grad-hero);
  transform: translateX(3px);
}

#articles article > a:hover::after {
  transform: translateX(3px);
}

#article-detail article {
  background: var(--surface-solid);
}

#article-detail article p:last-child {
  margin-bottom: 0;
}

/* ============ FAQ details ============ */
#faq details {
  margin: 0 0 12px;
  padding: 0;
  background: var(--surface-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  overflow: hidden;
  transition: border-color 0.3s var(--ease), box-shadow 0.3s var(--ease), background 0.3s var(--ease);
}

#faq details:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-sm);
}

#faq details[open] {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-soft);
  background: var(--surface-solid);
}

#faq summary {
  position: relative;
  padding: 16px 52px 16px 20px;
  font-weight: 650;
  font-size: 1rem;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  transition: color 0.2s var(--ease);
}

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

#faq summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1;
  color: var(--primary);
  background: var(--primary-soft);
  border-radius: 50%;
  transition: transform 0.3s var(--ease), background 0.3s var(--ease), color 0.3s var(--ease);
}

#faq details[open] summary {
  color: var(--primary);
}

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

#faq details p {
  margin: 0;
  padding: 0 20px 18px;
  animation: fadeSlide 0.3s var(--ease);
}

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

/* ============ Lists / HowTo ============ */
#howto ol,
#howto ul,
#products ul,
#solutions ul {
  padding-left: 0;
  list-style: none;
  counter-reset: step;
}

#howto ol > li {
  counter-increment: step;
  position: relative;
  padding: 12px 16px 12px 52px;
  margin-bottom: 10px;
  background: var(--surface-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: transform 0.28s var(--ease), border-color 0.28s var(--ease), box-shadow 0.28s var(--ease);
}

#howto ol > li::before {
  content: counter(step);
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  font-size: 0.82rem;
  font-weight: 700;
  color: #fff;
  background: var(--grad-hero);
  border-radius: 50%;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

#howto ol > li:hover {
  transform: translateX(4px);
  border-color: var(--primary);
  box-shadow: var(--shadow-sm);
}

#howto ul > li,
#products ul > li {
  position: relative;
  padding: 10px 14px 10px 38px;
  margin-bottom: 8px;
  background: var(--surface-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: transform 0.25s var(--ease), border-color 0.25s var(--ease), background 0.25s var(--ease);
}

#howto ul > li::before,
#products ul > li::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 50%;
  width: 9px;
  height: 9px;
  margin-top: -4.5px;
  border-radius: 3px;
  background: var(--grad-accent);
  transform: rotate(45deg);
  transition: transform 0.25s var(--ease);
}

#howto ul > li:hover,
#products ul > li:hover {
  transform: translateX(4px);
  border-color: var(--accent);
  background: var(--accent-soft);
}

#howto ul > li:hover::before,
#products ul > li:hover::before {
  transform: rotate(90deg) scale(1.15);
}

/* ============ Contact / Sitemap / Links ============ */
#contact address ul,
#sitemap ul,
#links ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 10px;
}

#sitemap ul,
#links ul {
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
}

#contact address ul {
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
}

#contact address li,
#sitemap li,
#links li {
  margin: 0;
  padding: 12px 16px;
  background: var(--surface-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  font-size: 0.92rem;
  transition: transform 0.28s var(--ease), border-color 0.28s var(--ease), box-shadow 0.28s var(--ease);
}

#contact address li:hover,
#sitemap li:hover,
#links li:hover {
  transform: translateY(-3px);
  border-color: var(--primary);
  box-shadow: var(--shadow-sm);
}

#sitemap a,
#links a {
  display: block;
  font-weight: 500;
}

#sitemap a::before {
  content: "▸ ";
  color: var(--accent);
  font-size: 0.8em;
}

/* ============ Legal / Author ============ */
#legal h3,
#knowledge h3 {
  padding-left: 12px;
  border-left: 3px solid var(--primary);
}

#knowledge h3 {
  border-left-color: var(--accent);
}

#author-info {
  background: var(--grad-glass) !important;
  border: 1px solid var(--border-strong) !important;
}

#author-info p:last-child {
  margin-bottom: 0;
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* ============ Footer ============ */
#site-footer {
  margin-top: 40px;
  padding: 44px 20px 36px;
  background: var(--grad-hero);
  color: rgba(255, 255, 255, 0.82);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  position: relative;
  overflow: hidden;
}

#site-footer::before {
  content: "";
  position: absolute;
  inset: auto -10% -60% auto;
  width: 420px;
  height: 420px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(251, 191, 36, 0.18), transparent 65%);
  pointer-events: none;
}

.footer-inner {
  position: relative;
  max-width: var(--max-w);
  margin: 0 auto;
  text-align: center;
}

#site-footer p {
  margin: 0 0 10px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.9rem;
}

#site-footer p:last-child {
  margin-bottom: 0;
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.6);
}

#site-footer strong {
  color: #fff;
  font-size: 1.05rem;
}

#site-footer a {
  color: var(--accent);
  font-weight: 500;
  border-bottom: 1px dashed transparent;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

#site-footer a:hover {
  color: #fff;
  border-bottom-color: rgba(255, 255, 255, 0.6);
}

/* ============ Back to top ============ */
#back-to-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 90;
  padding: 12px 18px;
  font-family: inherit;
  font-size: 0.84rem;
  font-weight: 700;
  color: #fff;
  cursor: pointer;
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 999px;
  background: var(--grad-hero);
  box-shadow: 0 10px 26px rgba(30, 58, 138, 0.4);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px) scale(0.92);
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease), visibility 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

#back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
}

#back-to-top:hover {
  transform: translateY(-4px) scale(1.04);
  box-shadow: 0 16px 36px rgba(30, 58, 138, 0.5);
}

/* ============ Scroll reveal ============ */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
  will-change: opacity, transform;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============ Responsive ============ */
@media (max-width: 1080px) {
  .header-inner {
    gap: 12px;
  }
  .main-nav a {
    padding: 6px 8px;
    font-size: 0.84rem;
  }
  .site-search input {
    width: 150px;
  }
  .site-search input:focus {
    width: 180px;
  }
}

@media (max-width: 900px) {
  #site-header nav[aria-label="主导航"] {
    display: none;
  }
  #menu-toggle {
    display: inline-block;
  }
  .header-inner {
    min-height: 60px;
    padding: 8px 16px;
    gap: 10px;
  }
  .site-search {
    order: 3;
    flex: 1 1 100%;
  }
  .site-search input {
    flex: 1 1 auto;
    width: auto;
  }
  .site-search input:focus {
    width: auto;
  }
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  main {
    padding: 0 14px 30px;
  }
  main > section {
    margin: 22px 0;
    border-radius: var(--radius-lg);
  }
  #hero {
    border-radius: var(--radius-lg) !important;
  }
}

@media (max-width: 600px) {
  body {
    font-size: 15px;
  }
  .header-inner {
    padding: 8px 14px;
  }
  .brand {
    font-size: 1rem;
  }
  .brand svg {
    width: 34px;
    height: 34px;
  }
  #theme-toggle,
  #menu-toggle {
    padding: 7px 12px;
    font-size: 0.8rem;
  }
  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }
  .btn-primary,
  .btn-secondary {
    width: 100%;
  }
  .hero-stats {
    gap: 10px;
  }
  .hero-stats li {
    padding: 14px 8px;
  }
  .hero-stats span {
    font-size: 0.76rem;
  }
  #mobile-menu ul {
    grid-template-columns: 1fr;
  }
  #contact address ul,
  #sitemap ul,
  #links ul {
    grid-template-columns: 1fr;
  }
  #faq summary {
    padding: 14px 46px 14px 16px;
    font-size: 0.95rem;
  }
  #howto ol > li {
    padding: 10px 12px 10px 46px;
  }
  #back-to-top {
    right: 14px;
    bottom: 14px;
    padding: 10px 14px;
    font-size: 0.78rem;
  }
  main > section {
    padding: 22px 16px;
  }
}

@media (max-width: 380px) {
  .hero-stats {
    grid-template-columns: 1fr;
  }
}

/* ============ Motion preferences ============ */
@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;
  }
  .reveal {
    opacity: 1;
    transform: none;
  }
}

/* ============ Print ============ */
@media print {
  #site-header,
  #back-to-top,
  #site-footer,
  .hero-actions,
  .site-search {
    display: none !important;
  }
  body {
    background: #fff;
    color: #000;
  }
  main > section {
    box-shadow: none;
    border: 1px solid #ddd;
    break-inside: avoid;
  }
  #hero {
    background: #f1f5f9 !important;
    color: #000;
  }
  #hero h1,
  #hero .hero-lead,
  .hero-figure figcaption,
  .hero-stats span {
    color: #000 !important;
  }
}