:root {
  --primary: #1a3a5c;
  --primary-light: #2b5a8a;
  --primary-dark: #0f2438;
  --accent: #f5a623;
  --accent-light: #ffc85c;
  --accent-dark: #d18a0f;
  --bg: #f4f7fb;
  --bg-alt: #ffffff;
  --bg-elev: #ffffff;
  --text: #1c2733;
  --text-soft: #4a5a6a;
  --text-muted: #7a8a9a;
  --border: #dde5ee;
  --border-soft: #eaf0f6;
  --shadow-sm: 0 2px 8px rgba(26, 58, 92, 0.06);
  --shadow-md: 0 8px 24px rgba(26, 58, 92, 0.10);
  --shadow-lg: 0 16px 48px rgba(26, 58, 92, 0.14);
  --glass-bg: rgba(255, 255, 255, 0.72);
  --glass-border: rgba(255, 255, 255, 0.55);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --gradient-banner: linear-gradient(135deg, #1a3a5c 0%, #2b5a8a 45%, #3d7ab8 100%);
  --gradient-accent: linear-gradient(135deg, #f5a623 0%, #ffc85c 100%);
  --gradient-soft: linear-gradient(160deg, #eef4fb 0%, #f8fbff 100%);
  --transition: 0.3s cubic-bezier(0.25, 0.8, 0.35, 1);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

body.dark-mode {
  --primary: #3d7ab8;
  --primary-light: #5a9ad8;
  --primary-dark: #0a1828;
  --accent: #ffc85c;
  --accent-light: #ffe09a;
  --accent-dark: #f5a623;
  --bg: #0d1622;
  --bg-alt: #14202e;
  --bg-elev: #1a2838;
  --text: #e8eef5;
  --text-soft: #b0c0d0;
  --text-muted: #7a8a9a;
  --border: #2a3a4c;
  --border-soft: #223040;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
  --glass-bg: rgba(20, 32, 46, 0.75);
  --glass-border: rgba(255, 255, 255, 0.08);
  --gradient-banner: linear-gradient(135deg, #0a1828 0%, #14283e 45%, #1e3e5e 100%);
  --gradient-soft: linear-gradient(160deg, #0d1622 0%, #14202e 100%);
}

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

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

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

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

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

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

h1, h2, h3, h4, h5, h6 {
  line-height: 1.35;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.6em;
}

h1 { font-size: clamp(1.6rem, 4vw, 2.4rem); }
h2 { font-size: clamp(1.35rem, 3vw, 1.9rem); }
h3 { font-size: clamp(1.15rem, 2.4vw, 1.4rem); }
h4 { font-size: clamp(1rem, 2vw, 1.15rem); }

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

ul, ol {
  margin-bottom: 1em;
  padding-left: 1.4em;
  color: var(--text-soft);
}

li {
  margin-bottom: 0.4em;
}

blockquote {
  margin: 1.2em 0;
  padding: 1em 1.4em;
  background: var(--gradient-soft);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-sm);
  color: var(--text-soft);
  font-style: italic;
  box-shadow: var(--shadow-sm);
}

address {
  font-style: normal;
}

/* ============ HEADER ============ */
#site-header {
  position: relative;
  z-index: 100;
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border-soft);
  transition: background-color var(--transition), box-shadow var(--transition);
}

#site-header.sticky {
  position: sticky;
  top: 0;
  box-shadow: var(--shadow-md);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: var(--glass-bg);
  border-bottom: 1px solid var(--glass-border);
}

.topbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding: 0.45rem clamp(1rem, 4vw, 3rem);
  background: var(--primary-dark);
  color: #cdd9e5;
  font-size: 0.82rem;
}

.topbar p {
  margin: 0;
  color: inherit;
}

.topbar nav {
  display: flex;
  gap: 1.2rem;
}

.topbar nav a {
  color: #cdd9e5;
  font-size: 0.82rem;
}

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

.brandbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  padding: 0.9rem clamp(1rem, 4vw, 3rem);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: 0.02em;
}

.logo:hover {
  color: var(--primary-light);
}

.logo svg {
  border-radius: 10px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition);
}

.logo:hover svg {
  transform: rotate(-6deg) scale(1.05);
}

.brandbar form[role="search"] {
  display: flex;
  flex: 1 1 240px;
  max-width: 520px;
  gap: 0.5rem;
  position: relative;
}

.brandbar form[role="search"] label {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.brandbar input[type="search"] {
  flex: 1;
  padding: 0.6rem 1rem;
  font-size: 0.92rem;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.brandbar input[type="search"]:focus {
  border-color: var(--primary-light);
  box-shadow: 0 0 0 3px rgba(43, 90, 138, 0.15);
}

.brandbar button[type="submit"] {
  padding: 0.6rem 1.3rem;
  font-size: 0.9rem;
  font-family: inherit;
  font-weight: 600;
  color: #fff;
  background: var(--gradient-banner);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
}

.brandbar button[type="submit"]:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

#theme-toggle,
#menu-toggle {
  padding: 0.55rem 1rem;
  font-size: 0.85rem;
  font-family: inherit;
  font-weight: 600;
  color: var(--primary);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

#theme-toggle:hover,
#menu-toggle:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

#menu-toggle {
  display: none;
}

/* ============ MAIN NAV ============ */
#main-nav {
  background: var(--bg-alt);
  border-top: 1px solid var(--border-soft);
}

#main-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.2rem;
  list-style: none;
  margin: 0;
  padding: 0 clamp(1rem, 4vw, 3rem);
}

#main-nav li {
  margin: 0;
}

#main-nav a {
  display: block;
  padding: 0.75rem 0.95rem;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-soft);
  border-bottom: 2px solid transparent;
  transition: all var(--transition);
}

#main-nav a:hover {
  color: var(--primary);
  border-bottom-color: var(--accent);
  background: var(--gradient-soft);
}

/* ============ MAIN LAYOUT ============ */
main {
  max-width: 1200px;
  margin: 0 auto;
  padding: clamp(1rem, 3vw, 2rem) clamp(1rem, 4vw, 3rem) 3rem;
}

main > nav[aria-label="面包屑导航"] {
  margin-bottom: 1.2rem;
}

main > nav[aria-label="面包屑导航"] ol {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

main > nav[aria-label="面包屑导航"] li {
  margin: 0;
}

main > nav[aria-label="面包屑导航"] li + li::before {
  content: "›";
  margin-right: 0.4rem;
  color: var(--text-muted);
}

main > nav[aria-label="面包屑导航"] a {
  color: var(--text-muted);
}

main > nav[aria-label="面包屑导航"] a:hover {
  color: var(--primary);
}

/* ============ SECTIONS ============ */
section {
  margin-bottom: clamp(2rem, 5vw, 3.5rem);
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.25, 0.8, 0.35, 1);
}

section.visible {
  opacity: 1;
  transform: translateY(0);
}

section > h2 {
  position: relative;
  padding-bottom: 0.55rem;
  margin-bottom: 1.1rem;
}

section > h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 56px;
  height: 4px;
  border-radius: 2px;
  background: var(--gradient-accent);
}

/* ============ HERO ============ */
#hero {
  position: relative;
  padding: clamp(1.6rem, 4vw, 2.8rem);
  border-radius: var(--radius-xl);
  background: var(--gradient-banner);
  color: #fff;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

#hero::before {
  content: "";
  position: absolute;
  top: -40%;
  right: -15%;
  width: 55%;
  height: 140%;
  background: radial-gradient(circle, rgba(245, 166, 35, 0.28) 0%, transparent 65%);
  pointer-events: none;
}

#hero::after {
  content: "";
  position: absolute;
  bottom: -50%;
  left: -10%;
  width: 45%;
  height: 120%;
  background: radial-gradient(circle, rgba(90, 154, 216, 0.35) 0%, transparent 60%);
  pointer-events: none;
}

#hero h1 {
  position: relative;
  z-index: 1;
  color: #fff;
  margin-bottom: 0.8rem;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.25);
}

#hero > p {
  position: relative;
  z-index: 1;
  color: rgba(255, 255, 255, 0.88);
  max-width: 820px;
}

#hero > p a {
  display: inline-block;
  margin: 0.5rem 0.6rem 0 0;
  padding: 0.6rem 1.4rem;
  font-weight: 600;
  color: var(--primary-dark);
  background: var(--gradient-accent);
  border-radius: 999px;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition), box-shadow var(--transition);
}

#hero > p a:hover {
  transform: translateY(-3px) scale(1.03);
  box-shadow: var(--shadow-lg);
  color: var(--primary-dark);
}

#hero > p a + a {
  color: #fff;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.4);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

#hero > p a + a:hover {
  background: rgba(255, 255, 255, 0.26);
  color: #fff;
}

#banner-carousel {
  position: relative;
  z-index: 1;
  margin: 1.4rem 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.18);
}

#banner-carousel figure {
  margin: 0;
  position: relative;
}

#banner-carousel svg {
  width: 100%;
  height: auto;
  display: block;
}

#banner-carousel figcaption {
  padding: 0.7rem 1.2rem;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.8);
  background: rgba(0, 0, 0, 0.22);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

#hero > ul {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.8rem;
  list-style: none;
  margin: 1.4rem 0;
  padding: 0;
}

#hero > ul li {
  margin: 0;
  padding: 1rem 0.6rem;
  text-align: center;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.85);
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: transform var(--transition), background var(--transition);
}

#hero > ul li:hover {
  transform: translateY(-4px);
  background: rgba(255, 255, 255, 0.18);
}

#hero > ul strong {
  display: block;
  font-size: clamp(1.3rem, 3vw, 1.8rem);
  font-weight: 800;
  color: var(--accent-light);
  line-height: 1.2;
  margin-bottom: 0.2rem;
}

/* ============ CARDS (generic content sections) ============ */
#intro,
#about,
#products,
#solutions,
#scenarios,
#cases,
#news,
#articles,
#howto,
#knowledge,
#faq,
#contact,
#sitemap {
  padding: clamp(1.4rem, 3.5vw, 2.4rem);
  background: var(--bg-alt);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-soft);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition);
}

#intro:hover,
#about:hover,
#products:hover,
#solutions:hover,
#scenarios:hover,
#cases:hover,
#news:hover,
#articles:hover,
#howto:hover,
#knowledge:hover,
#contact:hover,
#sitemap:hover {
  box-shadow: var(--shadow-md);
}

/* ============ PRODUCTS / SOLUTIONS highlight blocks ============ */
#products h3,
#solutions h3,
#scenarios h3,
#cases h3,
#howto h3,
#knowledge h3 {
  padding-left: 0.85rem;
  border-left: 4px solid var(--accent);
  margin-top: 1.4rem;
}

#products h4 {
  color: var(--primary-light);
  margin-top: 1rem;
}

#products > ul,
#scenarios > ul {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.7rem;
  list-style: none;
  padding: 0;
}

#products > ul li,
#scenarios > ul li {
  margin: 0;
  padding: 0.85rem 1.1rem;
  background: var(--gradient-soft);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-md);
  font-size: 0.92rem;
  transition: transform var(--transition), box-shadow var(--transition);
}

#products > ul li:hover,
#scenarios > ul li:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

/* ============ ABOUT timeline ============ */
#about ul {
  list-style: none;
  padding-left: 0;
  position: relative;
}

#about ul::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: var(--border);
}

#about ul li {
  position: relative;
  padding-left: 1.8rem;
  margin-bottom: 0.8rem;
}

#about ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55rem;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--gradient-accent);
  border: 3px solid var(--bg-alt);
  box-shadow: 0 0 0 2px var(--accent);
}

/* ============ CASES blockquote ============ */
#cases blockquote {
  transition: transform var(--transition), box-shadow var(--transition);
}

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

/* ============ NEWS list ============ */
#news > ul {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  list-style: none;
  padding: 0;
}

#news > ul > li {
  margin: 0;
  padding: 1.2rem;
  background: var(--gradient-soft);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-md);
  transition: transform var(--transition), box-shadow var(--transition);
}

#news > ul > li:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

#news > ul h3 {
  font-size: 1.05rem;
  margin-bottom: 0.4rem;
}

#news > ul p {
  font-size: 0.88rem;
  margin-bottom: 0.4rem;
}

#news > ul p:first-of-type {
  font-size: 0.78rem;
  color: var(--accent-dark);
  font-weight: 600;
}

/* ============ ARTICLES ============ */
#articles {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

#articles > p {
  margin-bottom: 0.4rem;
}

#articles article {
  padding: 1.2rem 1.4rem;
  background: var(--gradient-soft);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-md);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

#articles article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-light);
}

#articles article h3 {
  font-size: 1.1rem;
  margin-bottom: 0.3rem;
}

#articles article p {
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

#articles article p:first-of-type {
  font-size: 0.78rem;
  color: var(--text-muted);
}

#articles article a {
  display: inline-block;
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--primary-light);
  transition: transform var(--transition), color var(--transition);
}

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

/* ============ HOWTO steps ============ */
#howto ol {
  counter-reset: step;
  list-style: none;
  padding-left: 0;
}

#howto ol li {
  position: relative;
  padding: 0.8rem 1rem 0.8rem 3rem;
  margin-bottom: 0.6rem;
  background: var(--gradient-soft);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-md);
  counter-increment: step;
  transition: transform var(--transition), box-shadow var(--transition);
}

#howto ol li:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-md);
}

#howto ol li::before {
  content: counter(step);
  position: absolute;
  left: 0.8rem;
  top: 50%;
  transform: translateY(-50%);
  width: 26px;
  height: 26px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.82rem;
  font-weight: 700;
  color: #fff;
  background: var(--gradient-banner);
  border-radius: 50%;
}

#howto ul {
  list-style: none;
  padding-left: 0;
}

#howto ul li {
  position: relative;
  padding-left: 1.4rem;
}

#howto ul li::before {
  content: "✕";
  position: absolute;
  left: 0;
  color: var(--accent-dark);
  font-weight: 700;
  font-size: 0.8rem;
}

#howto > h3:last-of-type + p {
  padding: 1rem 1.2rem;
  background: var(--gradient-soft);
  border-radius: var(--radius-md);
  border-left: 4px solid var(--accent);
}

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

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

#faq details[open] {
  border-color: var(--primary-light);
  box-shadow: var(--shadow-md);
}

#faq summary {
  position: relative;
  padding: 1rem 2.6rem 1rem 1.2rem;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  transition: color var(--transition), background var(--transition);
}

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

#faq summary:hover {
  color: var(--primary-light);
  background: rgba(43, 90, 138, 0.05);
}

#faq summary::after {
  content: "+";
  position: absolute;
  right: 1.2rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--accent);
  transition: transform var(--transition);
}

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

#faq details p {
  padding: 0 1.2rem 1.1rem;
  margin: 0;
  font-size: 0.9rem;
  animation: fadeSlide 0.35s ease;
}

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

/* ============ CONTACT ============ */
#contact address ul {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.7rem;
}

#contact address ul li {
  margin: 0;
  padding: 0.85rem 1.1rem;
  background: var(--gradient-soft);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  transition: transform var(--transition), box-shadow var(--transition);
}

#contact address ul li:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

#contact address ul li a {
  font-weight: 600;
}

/* ============ SITEMAP ============ */
#sitemap > ul {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 0.5rem;
  list-style: none;
  padding: 0;
}

#sitemap > ul li {
  margin: 0;
}

#sitemap > ul a {
  display: block;
  padding: 0.55rem 0.9rem;
  font-size: 0.88rem;
  color: var(--text-soft);
  background: var(--gradient-soft);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

#sitemap > ul a:hover {
  color: #fff;
  background: var(--gradient-banner);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

#sitemap h3 {
  margin-top: 1.4rem;
  padding-left: 0.85rem;
  border-left: 4px solid var(--accent);
}

#sitemap h3 + ul {
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

/* ============ FOOTER ============ */
footer {
  margin-top: 2rem;
  padding: clamp(1.6rem, 4vw, 2.8rem) clamp(1rem, 4vw, 3rem) 1.4rem;
  background: var(--primary-dark);
  color: #b8c8d8;
  border-top: 4px solid var(--accent);
}

footer section,
footer nav {
  max-width: 1200px;
  margin: 0 auto 1.4rem;
}

footer h2 {
  font-size: 1.05rem;
  color: #fff;
  margin-bottom: 0.6rem;
}

footer h3 {
  font-size: 0.92rem;
  color: var(--accent-light);
  margin-bottom: 0.3rem;
  margin-top: 0.8rem;
}

footer p {
  font-size: 0.86rem;
  color: #9fb2c4;
  margin-bottom: 0.6rem;
}

footer a {
  color: #cdd9e5;
}

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

footer nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.4rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

footer nav li {
  margin: 0;
}

footer nav a {
  font-size: 0.88rem;
  transition: color var(--transition);
}

footer > p {
  max-width: 1200px;
  margin: 1.4rem auto 0;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 0.8rem;
  color: #7a8a9a;
  text-align: center;
}

/* ============ BACK TO TOP ============ */
#back-to-top {
  position: fixed;
  right: 1.4rem;
  bottom: 1.4rem;
  z-index: 200;
  display: none;
  padding: 0.7rem 1rem;
  font-size: 0.82rem;
  font-family: inherit;
  font-weight: 600;
  color: #fff;
  background: var(--gradient-banner);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  transition: transform var(--transition), box-shadow var(--transition);
}

#back-to-top:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 50px rgba(26, 58, 92, 0.35);
}

/* ============ SVG loaded animation ============ */
svg.loaded {
  animation: svgFade 0.6s ease;
}

@keyframes svgFade {
  from { opacity: 0.4; }
  to { opacity: 1; }
}

/* ============ RESPONSIVE ============ */
@media (max-width: 960px) {
  #hero > ul {
    grid-template-columns: repeat(2, 1fr);
  }
}

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

  .topbar {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.3rem;
  }

  .brandbar {
    gap: 0.6rem;
  }

  .brandbar form[role="search"] {
    order: 3;
    flex: 1 1 100%;
    max-width: none;
  }

  #menu-toggle {
    display: inline-block;
    margin-left: auto;
  }

  #main-nav {
    display: none;
  }

  #main-nav.open {
    display: block;
    animation: navDrop 0.3s ease;
  }

  #main-nav ul {
    flex-direction: column;
    gap: 0;
    padding: 0.4rem 1rem 0.8rem;
  }

  #main-nav a {
    padding: 0.7rem 0.6rem;
    border-bottom: 1px solid var(--border-soft);
  }

  #main-nav a:hover {
    border-bottom-color: var(--border-soft);
    border-left: 3px solid var(--accent);
    padding-left: 0.9rem;
  }

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

  #hero {
    border-radius: var(--radius-lg);
  }

  #hero > ul {
    gap: 0.6rem;
  }

  #hero > ul li {
    padding: 0.8rem 0.4rem;
    font-size: 0.78rem;
  }

  #hero > p a {
    display: block;
    text-align: center;
    margin: 0.5rem 0 0;
  }

  #hero > p a + a {
    margin-top: 0.6rem;
  }

  #articles,
  #intro,
  #about,
  #products,
  #solutions,
  #scenarios,
  #cases,
  #news,
  #howto,
  #knowledge,
  #faq,
  #contact,
  #sitemap {
    padding: 1.2rem;
    border-radius: var(--radius-md);
  }

  #back-to-top {
    right: 1rem;
    bottom: 1rem;
    padding: 0.6rem 0.85rem;
  }
}

@media (max-width: 480px) {
  #hero > ul {
    grid-template-columns: 1fr 1fr;
  }

  .logo {
    font-size: 1.05rem;
  }

  .logo svg {
    width: 38px;
    height: 38px;
  }

  #theme-toggle,
  #menu-toggle {
    padding: 0.5rem 0.75rem;
    font-size: 0.78rem;
  }

  #faq summary {
    font-size: 0.9rem;
    padding: 0.9rem 2.4rem 0.9rem 1rem;
  }

  #products > ul,
  #scenarios > ul,
  #contact address ul {
    grid-template-columns: 1fr;
  }
}

/* ============ REDUCED MOTION ============ */
@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;
    transform: none;
  }
}