:root {
  --color-primary: #1a3a6b;
  --color-primary-light: #4a7bc8;
  --color-primary-lighter: #7aa5e0;
  --color-accent: #ffb703;
  --color-accent-dark: #e0a000;
  --color-bg: #f5f8fc;
  --color-bg-alt: #e8eef7;
  --color-surface: #ffffff;
  --color-surface-glass: rgba(255, 255, 255, 0.72);
  --color-border: #d5e0ef;
  --color-text: #1d2b3f;
  --color-text-soft: #4a5a72;
  --color-text-muted: #78889e;
  --color-shadow: rgba(26, 58, 107, 0.12);
  --color-shadow-strong: rgba(26, 58, 107, 0.22);
  --gradient-hero: linear-gradient(135deg, #1a3a6b 0%, #2f5a9e 45%, #4a7bc8 100%);
  --gradient-accent: linear-gradient(135deg, #ffb703 0%, #ff9500 100%);
  --gradient-soft: linear-gradient(135deg, #eef3fa 0%, #dfe9f6 100%);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-xl: 32px;
  --radius-pill: 999px;
  --header-h: 72px;
  --max-w: 1200px;
  --transition: 0.32s cubic-bezier(0.22, 1, 0.36, 1);
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

[data-theme="dark"] {
  --color-primary: #7aa5e0;
  --color-primary-light: #4a7bc8;
  --color-primary-lighter: #2f5a9e;
  --color-accent: #ffc233;
  --color-accent-dark: #ffb703;
  --color-bg: #0d1626;
  --color-bg-alt: #13203a;
  --color-surface: #172440;
  --color-surface-glass: rgba(23, 36, 64, 0.72);
  --color-border: #26375a;
  --color-text: #e6eefb;
  --color-text-soft: #b3c4dd;
  --color-text-muted: #8499b8;
  --color-shadow: rgba(0, 0, 0, 0.35);
  --color-shadow-strong: rgba(0, 0, 0, 0.55);
  --gradient-hero: linear-gradient(135deg, #0f2038 0%, #1a3a6b 50%, #2f5a9e 100%);
  --gradient-soft: linear-gradient(135deg, #13203a 0%, #1b2c4d 100%);
}

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

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

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text);
  background-color: var(--color-bg);
  background-image:
    radial-gradient(1200px 600px at 85% -10%, rgba(74, 123, 200, 0.14), transparent 60%),
    radial-gradient(900px 500px at 0% 20%, rgba(255, 183, 3, 0.08), transparent 55%);
  background-attachment: fixed;
  transition: background-color var(--transition), color var(--transition);
  overflow-x: hidden;
}

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

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-dark);
}

h1,
h2,
h3,
h4 {
  line-height: 1.3;
  margin: 0 0 0.6em;
  color: var(--color-text);
  font-weight: 800;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(1.7rem, 3.4vw, 2.6rem);
}

h2 {
  font-size: clamp(1.4rem, 2.6vw, 2rem);
}

h3 {
  font-size: clamp(1.15rem, 1.9vw, 1.4rem);
  margin-top: 1.6em;
}

h4 {
  font-size: 1.06rem;
  margin-top: 1.4em;
  color: var(--color-primary-light);
}

p {
  margin: 0 0 1.1em;
  color: var(--color-text-soft);
}

ul,
ol {
  color: var(--color-text-soft);
}

button {
  font-family: inherit;
  cursor: pointer;
}

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

.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 9999;
  background: var(--color-accent);
  color: #1a1a1a;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  font-weight: 700;
  transition: top var(--transition);
}

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

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--color-surface-glass);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  backdrop-filter: blur(18px) saturate(160%);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow var(--transition), background var(--transition);
}

.site-header.is-scrolled {
  box-shadow: 0 8px 30px var(--color-shadow);
}

.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 20px;
}

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

.brand-logo {
  border-radius: 11px;
  box-shadow: 0 6px 16px var(--color-shadow);
  transition: transform var(--transition);
}

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

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-text strong {
  font-size: 1.12rem;
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: 0.02em;
}

.brand-text span {
  font-size: 0.72rem;
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
}

.main-nav {
  flex: 1;
  min-width: 0;
}

.main-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 4px;
  flex-wrap: nowrap;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.main-nav a {
  display: block;
  padding: 8px 12px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text-soft);
  border-radius: var(--radius-pill);
  white-space: nowrap;
  transition: background var(--transition), color var(--transition), transform var(--transition);
}

.main-nav a:hover,
.main-nav a:focus-visible {
  background: rgba(74, 123, 200, 0.14);
  color: var(--color-primary-light);
  transform: translateY(-1px);
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.site-search {
  display: flex;
  align-items: center;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  padding: 4px 4px 4px 14px;
  transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}

.site-search:focus-within {
  border-color: var(--color-primary-light);
  box-shadow: 0 0 0 4px rgba(74, 123, 200, 0.16);
  background: var(--color-surface);
}

.site-search input {
  border: 0;
  background: transparent;
  color: var(--color-text);
  font-size: 0.85rem;
  width: 180px;
  padding: 6px 0;
  outline: none;
}

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

.site-search button {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border: 0;
  border-radius: 50%;
  background: var(--gradient-accent);
  color: #1a1a1a;
  transition: transform var(--transition), filter var(--transition);
}

.site-search button:hover {
  transform: scale(1.08);
  filter: brightness(1.06);
}

.theme-toggle,
.menu-toggle {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--color-border);
  border-radius: 50%;
  background: var(--color-surface);
  color: var(--color-text-soft);
  transition: transform var(--transition), background var(--transition), color var(--transition), border-color var(--transition);
}

.theme-toggle:hover,
.menu-toggle:hover {
  transform: rotate(12deg) scale(1.06);
  color: var(--color-accent-dark);
  border-color: var(--color-accent);
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
}

.menu-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform var(--transition), opacity var(--transition);
}

.menu-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.menu-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* ---------- Breadcrumb ---------- */
.breadcrumb {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 18px 24px 0;
}

.breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--color-text-muted);
}

.breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--color-text-muted);
  opacity: 0.6;
}

.breadcrumb a {
  color: var(--color-text-soft);
  font-weight: 600;
}

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

/* ---------- Main layout ---------- */
main {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px 60px;
}

.section {
  position: relative;
  margin-top: 56px;
  padding: 40px clamp(20px, 4vw, 44px);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: 0 10px 40px -18px var(--color-shadow);
  transition: box-shadow var(--transition), border-color var(--transition), transform var(--transition);
}

.section:hover {
  box-shadow: 0 18px 50px -20px var(--color-shadow-strong);
}

.section > h2 {
  position: relative;
  padding-bottom: 14px;
  margin-bottom: 24px;
}

.section > h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 64px;
  height: 4px;
  border-radius: 4px;
  background: var(--gradient-accent);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  margin-top: 24px;
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: var(--gradient-hero);
  box-shadow: 0 24px 60px -24px var(--color-shadow-strong);
  isolation: isolate;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(600px 300px at 90% 10%, rgba(255, 183, 3, 0.22), transparent 65%),
    radial-gradient(500px 260px at 5% 90%, rgba(122, 165, 224, 0.28), transparent 60%);
  pointer-events: none;
  z-index: -1;
}

.hero-slider {
  position: relative;
  min-height: 420px;
}

.slide {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 32px;
  padding: clamp(28px, 5vw, 60px);
  opacity: 0;
  visibility: hidden;
  transform: translateY(18px) scale(0.99);
  transition: opacity 0.6s ease, transform 0.6s ease, visibility 0.6s;
}

.slide.is-active {
  position: relative;
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
}

.slide-content h1,
.slide-content h2 {
  color: #ffffff;
  text-shadow: 0 2px 18px rgba(0, 0, 0, 0.22);
}

.slide-content p {
  color: rgba(255, 255, 255, 0.86);
  font-size: 1rem;
  max-width: 60ch;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  font-size: 0.95rem;
  font-weight: 700;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), color var(--transition);
  will-change: transform;
}

.btn-primary {
  background: var(--gradient-accent);
  color: #1a1a1a;
  box-shadow: 0 10px 24px -8px rgba(255, 183, 3, 0.7);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  color: #1a1a1a;
  transform: translateY(-3px);
  box-shadow: 0 16px 32px -10px rgba(255, 183, 3, 0.85);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.12);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.4);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.22);
  transform: translateY(-3px);
}

.slide-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.slide-visual svg {
  width: 100%;
  max-width: 360px;
  border-radius: var(--radius-md);
  box-shadow: 0 22px 50px -18px rgba(0, 0, 0, 0.5);
  transition: transform 0.6s ease;
}

.slide.is-active .slide-visual svg {
  animation: floatY 6s ease-in-out infinite;
}

@keyframes floatY {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.slider-dots {
  position: absolute;
  left: 50%;
  bottom: 20px;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
  z-index: 5;
}

.slider-dots button {
  width: 10px;
  height: 10px;
  padding: 0;
  border: 0;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.45);
  transition: width var(--transition), background var(--transition);
}

.slider-dots button[aria-selected="true"] {
  width: 30px;
  background: var(--color-accent);
  box-shadow: 0 0 14px rgba(255, 183, 3, 0.7);
}

/* ---------- Stats ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 28px;
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 26px 16px;
  text-align: center;
  background: var(--color-surface-glass);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: 0 8px 28px -16px var(--color-shadow);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.stat-item:hover {
  transform: translateY(-6px);
  border-color: var(--color-primary-light);
  box-shadow: 0 18px 40px -18px var(--color-shadow-strong);
}

.stat-num {
  font-size: clamp(1.6rem, 3vw, 2.3rem);
  font-weight: 900;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  font-weight: 600;
}

/* ---------- Products / cards ---------- */
#products > h3 {
  padding: 20px 22px;
  border-radius: var(--radius-md);
  background: var(--gradient-soft);
  border-left: 5px solid var(--color-accent);
  transition: transform var(--transition), box-shadow var(--transition);
}

#products > h3:hover {
  transform: translateX(6px);
  box-shadow: 0 10px 26px -16px var(--color-shadow-strong);
}

/* ---------- Articles ---------- */
.article-card {
  position: relative;
  padding: 24px 26px;
  margin-bottom: 18px;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), background var(--transition);
}

.article-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  bottom: 18px;
  width: 4px;
  border-radius: 4px;
  background: var(--gradient-accent);
  opacity: 0;
  transform: scaleY(0.4);
  transition: opacity var(--transition), transform var(--transition);
}

.article-card:hover {
  transform: translateY(-4px);
  background: var(--color-surface);
  border-color: var(--color-primary-light);
  box-shadow: 0 18px 40px -22px var(--color-shadow-strong);
}

.article-card:hover::before {
  opacity: 1;
  transform: scaleY(1);
}

.article-card h3 {
  margin-top: 0;
  margin-bottom: 8px;
  font-size: 1.15rem;
}

.article-card .meta {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-bottom: 10px;
  font-weight: 600;
}

.article-card .meta time {
  color: var(--color-primary-light);
}

.read-more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--color-primary-light);
  padding: 6px 0;
}

.read-more::after {
  content: "→";
  transition: transform var(--transition);
}

.read-more:hover::after {
  transform: translateX(5px);
}

/* ---------- Cases / blockquote ---------- */
blockquote {
  position: relative;
  margin: 22px 0;
  padding: 22px 26px 22px 60px;
  background: var(--gradient-soft);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  transition: transform var(--transition), box-shadow var(--transition);
}

blockquote::before {
  content: "\201C";
  position: absolute;
  left: 20px;
  top: 6px;
  font-size: 3.4rem;
  line-height: 1;
  font-family: Georgia, serif;
  color: var(--color-accent);
  opacity: 0.85;
}

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

blockquote:hover {
  transform: translateY(-3px);
  box-shadow: 0 16px 36px -20px var(--color-shadow-strong);
}

/* ---------- FAQ ---------- */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 8px;
}

.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-alt);
  overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}

.faq-item:hover {
  border-color: var(--color-primary-lighter);
}

.faq-item.is-open {
  border-color: var(--color-primary-light);
  background: var(--color-surface);
  box-shadow: 0 12px 32px -20px var(--color-shadow-strong);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  width: 100%;
  padding: 18px 22px;
  border: 0;
  background: transparent;
  text-align: left;
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text);
  transition: color var(--transition);
}

.faq-question::after {
  content: "+";
  flex-shrink: 0;
  display: grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--gradient-accent);
  color: #1a1a1a;
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1;
  transition: transform var(--transition), background var(--transition);
}

.faq-question[aria-expanded="true"] {
  color: var(--color-primary-light);
}

.faq-question[aria-expanded="true"]::after {
  content: "−";
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 22px 20px;
  animation: fadeSlide 0.4s ease;
}

.faq-answer p {
  margin: 0;
  color: var(--color-text-soft);
}

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

/* ---------- HowTo ---------- */
#howto ol {
  counter-reset: howto;
  list-style: none;
  padding: 0;
  margin: 0 0 1.4em;
  display: grid;
  gap: 12px;
}

#howto ol li {
  position: relative;
  counter-increment: howto;
  padding: 16px 20px 16px 62px;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: transform var(--transition), border-color var(--transition), background var(--transition);
}

#howto ol li::before {
  content: counter(howto);
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--gradient-hero);
  color: #fff;
  font-weight: 800;
  font-size: 0.9rem;
}

#howto ol li:hover {
  transform: translateX(6px);
  border-color: var(--color-primary-light);
  background: var(--color-surface);
}

/* ---------- Contact ---------- */
.contact-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 12px;
}

.contact-list li {
  padding: 14px 18px;
  background: var(--color-bg-alt);
  border-radius: var(--radius-sm);
  border-left: 4px solid var(--color-primary-light);
  transition: transform var(--transition), border-color var(--transition);
}

.contact-list li:hover {
  transform: translateX(5px);
  border-left-color: var(--color-accent);
}

.contact-list strong {
  color: var(--color-text);
}

/* ---------- Sitemap / links ---------- */
.sitemap-list,
.friend-links {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.sitemap-list a,
.friend-links a {
  display: inline-block;
  padding: 9px 18px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-text-soft);
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  transition: transform var(--transition), background var(--transition), color var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.sitemap-list a:hover,
.friend-links a:hover,
.sitemap-list a:focus-visible,
.friend-links a:focus-visible {
  color: #1a1a1a;
  background: var(--gradient-accent);
  border-color: transparent;
  transform: translateY(-3px);
  box-shadow: 0 10px 22px -10px rgba(255, 183, 3, 0.75);
}

/* ---------- Footer ---------- */
.site-footer {
  margin-top: 60px;
  background: var(--gradient-hero);
  color: rgba(255, 255, 255, 0.82);
  position: relative;
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(700px 320px at 85% 0%, rgba(255, 183, 3, 0.16), transparent 60%);
  pointer-events: none;
}

.footer-inner {
  position: relative;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 52px 24px 32px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 36px;
}

.footer-col h3 {
  color: #ffffff;
  font-size: 1.02rem;
  margin-top: 0;
  margin-bottom: 14px;
  position: relative;
  padding-bottom: 10px;
}

.footer-col h3::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 34px;
  height: 3px;
  border-radius: 3px;
  background: var(--color-accent);
}

.footer-col p {
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.9rem;
  margin: 0;
}

.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
  font-size: 0.88rem;
}

.footer-col ul li {
  color: rgba(255, 255, 255, 0.72);
}

.footer-col a {
  color: rgba(255, 255, 255, 0.82);
  border-bottom: 1px solid transparent;
  transition: color var(--transition), border-color var(--transition);
}

.footer-col a:hover {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

.footer-bottom {
  position: relative;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 22px 24px 34px;
  border-top: 1px solid rgba(255, 255, 255, 0.16);
  display: grid;
  gap: 8px;
  font-size: 0.8rem;
}

.footer-bottom p {
  margin: 0;
  color: rgba(255, 255, 255, 0.62);
}

/* ---------- Back to top ---------- */
.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 900;
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border: 0;
  border-radius: 50%;
  background: var(--gradient-accent);
  color: #1a1a1a;
  box-shadow: 0 12px 28px -10px rgba(255, 183, 3, 0.8);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px) scale(0.9);
  transition: opacity var(--transition), transform var(--transition), visibility var(--transition), filter var(--transition);
}

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

.back-to-top:hover {
  filter: brightness(1.08);
  transform: translateY(-4px) scale(1.05);
}

/* ---------- Scroll reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1), transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
  will-change: opacity, transform;
}

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

@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;
  }
}

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .main-nav a {
    padding: 8px 9px;
    font-size: 0.85rem;
  }
  .site-search input {
    width: 140px;
  }
  .slide {
    grid-template-columns: 1fr;
    text-align: left;
  }
  .slide-visual {
    order: -1;
  }
  .slide-visual svg {
    max-width: 300px;
  }
  .hero-slider {
    min-height: 560px;
  }
}

@media (max-width: 900px) {
  .header-inner {
    gap: 12px;
  }
  .site-search {
    display: none;
  }
  .menu-toggle {
    display: flex;
  }
  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    max-height: 0;
    overflow: hidden;
    background: var(--color-surface-glass);
    -webkit-backdrop-filter: blur(20px) saturate(160%);
    backdrop-filter: blur(20px) saturate(160%);
    border-bottom: 1px solid var(--color-border);
    transition: max-height 0.42s cubic-bezier(0.22, 1, 0.36, 1);
  }
  .main-nav.is-open {
    max-height: 70vh;
    overflow-y: auto;
    box-shadow: 0 20px 40px -20px var(--color-shadow-strong);
  }
  .main-nav ul {
    flex-direction: column;
    padding: 12px 20px 20px;
    gap: 2px;
  }
  .main-nav a {
    padding: 13px 16px;
    font-size: 0.96rem;
    border-radius: var(--radius-sm);
  }
  .stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-inner {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 680px) {
  :root {
    --header-h: 64px;
  }
  body {
    font-size: 15px;
  }
  .header-inner,
  .breadcrumb,
  main,
  .footer-inner,
  .footer-bottom {
    padding-left: 16px;
    padding-right: 16px;
  }
  .brand-text span {
    display: none;
  }
  .hero {
    border-radius: var(--radius-lg);
  }
  .slide {
    padding: 26px 20px 46px;
    gap: 20px;
  }
  .hero-slider {
    min-height: 620px;
  }
  .slide-visual svg {
    max-width: 240px;
  }
  .hero-actions .btn {
    flex: 1 1 auto;
    padding: 11px 18px;
  }
  .section {
    margin-top: 36px;
    padding: 26px 18px;
    border-radius: var(--radius-md);
  }
  .stats {
    gap: 12px;
  }
  .stat-item {
    padding: 20px 12px;
  }
  .article-card {
    padding: 20px 18px;
  }
  .faq-question {
    padding: 15px 16px;
    font-size: 0.94rem;
  }
  .faq-answer {
    padding: 0 16px 16px;
  }
  #howto ol li {
    padding: 14px 16px 14px 56px;
  }
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 26px;
    padding-top: 40px;
  }
  .back-to-top {
    right: 16px;
    bottom: 16px;
    width: 44px;
    height: 44px;
  }
}

@media (max-width: 400px) {
  .stats {
    grid-template-columns: 1fr;
  }
  .brand-text strong {
    font-size: 1rem;
  }
}

@media (hover: none) {
  .stat-item:hover,
  .article-card:hover,
  .faq-item:hover,
  #products > h3:hover,
  #howto ol li:hover,
  .contact-list li:hover,
  blockquote:hover {
    transform: none;
  }
}

@media print {
  .site-header,
  .breadcrumb,
  .slider-dots,
  .back-to-top,
  .hero-actions,
  .site-footer,
  .site-search,
  .theme-toggle,
  .menu-toggle {
    display: none !important;
  }
  body {
    background: #fff;
    color: #000;
  }
  .section,
  .hero {
    box-shadow: none;
    border: 1px solid #ccc;
  }
  .reveal {
    opacity: 1;
    transform: none;
  }
}