:root {
  --primary: #e63946;
  --primary-dark: #c1121f;
  --primary-light: #ff6b6b;
  --secondary: #1d3557;
  --secondary-light: #457b9d;
  --accent: #f1faee;
  --accent-warm: #ffd166;
  --bg: #f8f9fa;
  --bg-card: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.72);
  --text: #1a1a2e;
  --text-secondary: #4a4a5a;
  --text-muted: #8a8a9a;
  --border: rgba(0, 0, 0, 0.08);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.14);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  --transition: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --font: 'Microsoft YaHei', 'PingFang SC', 'Hiragino Sans GB', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f0f1a;
    --bg-card: #1a1a2e;
    --bg-glass: rgba(26, 26, 46, 0.78);
    --text: #eaeaea;
    --text-secondary: #b0b0c0;
    --text-muted: #707080;
    --border: rgba(255, 255, 255, 0.08);
    --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);
    --accent: #1a1a2e;
    --secondary: #16213e;
  }
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

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

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

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

a:hover {
  color: var(--primary-dark);
}

ul,
ol {
  list-style: none;
}

/* ===== 头部导航 ===== */
header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-glass);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition), box-shadow var(--transition);
}

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

.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.header-inner > a:first-child {
  flex-shrink: 0;
  transition: transform var(--transition);
}

.header-inner > a:first-child:hover {
  transform: scale(1.04);
}

.header-inner svg {
  width: 180px;
  height: 48px;
}

nav[aria-label="主导航"] {
  flex: 1;
}

nav[aria-label="主导航"] ul {
  display: flex;
  gap: 0.25rem;
  flex-wrap: wrap;
}

nav[aria-label="主导航"] a {
  display: inline-block;
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-full);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  position: relative;
  transition: all var(--transition);
}

nav[aria-label="主导航"] a::after {
  content: '';
  position: absolute;
  bottom: 0.15rem;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
  transform: translateX(-50%);
  transition: width var(--transition);
}

nav[aria-label="主导航"] a:hover {
  color: var(--primary);
  background: rgba(230, 57, 70, 0.08);
}

nav[aria-label="主导航"] a:hover::after {
  width: 60%;
}

form[role="search"] {
  display: flex;
  align-items: center;
  gap: 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  overflow: hidden;
  transition: box-shadow var(--transition), border-color var(--transition);
}

form[role="search"]:focus-within {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(230, 57, 70, 0.15);
}

form[role="search"] input {
  border: none;
  outline: none;
  background: transparent;
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  color: var(--text);
  width: 180px;
  font-family: var(--font);
}

form[role="search"] input::placeholder {
  color: var(--text-muted);
}

form[role="search"] button {
  border: none;
  background: var(--primary);
  color: #fff;
  padding: 0.5rem 1.2rem;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
  transition: background var(--transition);
}

form[role="search"] button:hover {
  background: var(--primary-dark);
}

/* ===== 面包屑 ===== */
.breadcrumb {
  max-width: 1280px;
  margin: 0 auto;
  padding: 1rem 1.5rem 0;
}

.breadcrumb ol {
  display: flex;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.breadcrumb li + li::before {
  content: '/';
  margin-right: 0.5rem;
  color: var(--text-muted);
}

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

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

/* ===== 主内容 ===== */
main {
  max-width: 1280px;
  margin: 0 auto;
  padding: 1rem 1.5rem 3rem;
}

section {
  margin-bottom: 3.5rem;
  scroll-margin-top: 90px;
  animation: fadeInUp 0.7s ease-out both;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

section:nth-child(1) { animation-delay: 0.05s; }
section:nth-child(2) { animation-delay: 0.1s; }
section:nth-child(3) { animation-delay: 0.15s; }
section:nth-child(4) { animation-delay: 0.2s; }
section:nth-child(5) { animation-delay: 0.25s; }
section:nth-child(6) { animation-delay: 0.3s; }
section:nth-child(7) { animation-delay: 0.35s; }
section:nth-child(8) { animation-delay: 0.4s; }
section:nth-child(9) { animation-delay: 0.45s; }
section:nth-child(10) { animation-delay: 0.5s; }

h1 {
  font-size: clamp(1.6rem, 4vw, 2.6rem);
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -0.02em;
  color: var(--text);
}

h2 {
  font-size: clamp(1.3rem, 3vw, 1.9rem);
  font-weight: 700;
  line-height: 1.35;
  margin-bottom: 1.25rem;
  color: var(--text);
  position: relative;
  padding-left: 1rem;
}

h2::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.2em;
  bottom: 0.2em;
  width: 4px;
  border-radius: 4px;
  background: linear-gradient(180deg, var(--primary), var(--primary-light));
}

h3 {
  font-size: clamp(1.05rem, 2.2vw, 1.3rem);
  font-weight: 700;
  margin: 1.5rem 0 0.75rem;
  color: var(--text);
}

h4 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text);
}

p {
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

/* ===== Hero ===== */
#hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: center;
  background: linear-gradient(135deg, #1d3557 0%, #e63946 50%, #ff6b6b 100%);
  border-radius: var(--radius-lg);
  padding: 3rem 2.5rem;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

#hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.12) 0%, transparent 70%);
  pointer-events: none;
}

#hero::after {
  content: '';
  position: absolute;
  bottom: -40%;
  left: -10%;
  width: 50%;
  height: 150%;
  background: radial-gradient(circle, rgba(241, 250, 238, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

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

.hero-content h1 {
  color: #fff;
  margin-bottom: 1rem;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.2);
}

.hero-content p {
  color: rgba(255, 255, 255, 0.9);
  font-size: 1.05rem;
  margin-bottom: 1.75rem;
  max-width: 500px;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 2rem;
  border-radius: var(--radius-full);
  font-size: 1rem;
  font-weight: 700;
  transition: all var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
  font-family: var(--font);
}

.btn-primary {
  background: #fff;
  color: var(--primary);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

.btn-primary:hover {
  background: var(--accent);
  color: var(--primary-dark);
  transform: translateY(-3px);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.22);
}

.btn-secondary {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.6);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: #fff;
  transform: translateY(-3px);
}

.hero-slider {
  position: relative;
  z-index: 1;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.25);
  transition: transform var(--transition);
}

.hero-slider:hover {
  transform: scale(1.02);
}

.hero-slider svg {
  width: 100%;
  height: auto;
  display: block;
}

/* ===== 品牌介绍 ===== */
#brand {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition), transform var(--transition);
}

#brand:hover {
  box-shadow: var(--shadow-md);
}

#brand ul {
  margin: 1rem 0;
  padding-left: 1.25rem;
}

#brand ul li {
  position: relative;
  padding-left: 1rem;
  margin-bottom: 0.6rem;
  color: var(--text-secondary);
}

#brand ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--primary);
}

#brand ul li strong {
  color: var(--text);
}

/* ===== 主营产品 ===== */
#products {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

#products:hover {
  box-shadow: var(--shadow-md);
}

#products ul {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
  margin: 1rem 0;
}

#products ul li {
  background: linear-gradient(135deg, rgba(230, 57, 70, 0.06), rgba(29, 53, 87, 0.06));
  padding: 1.25rem 1.25rem 1.25rem 1.75rem;
  border-radius: var(--radius-md);
  border-left: 4px solid var(--primary);
  color: var(--text-secondary);
  position: relative;
  transition: all var(--transition);
}

#products ul li:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-left-color: var(--primary-dark);
}

#products ul li strong {
  color: var(--text);
  display: block;
  margin-bottom: 0.25rem;
}

/* ===== 解决方案 ===== */
#solutions {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

#solutions:hover {
  box-shadow: var(--shadow-md);
}

#solutions ul {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin: 1rem 0;
}

#solutions ul li {
  background: linear-gradient(135deg, rgba(29, 53, 87, 0.06), rgba(69, 123, 157, 0.06));
  padding: 1.25rem;
  border-radius: var(--radius-md);
  border-top: 4px solid var(--secondary-light);
  color: var(--text-secondary);
  transition: all var(--transition);
}

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

#solutions ul li strong {
  color: var(--text);
  display: block;
  margin-bottom: 0.25rem;
}

/* ===== 客户案例 ===== */
#cases {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

#cases:hover {
  box-shadow: var(--shadow-md);
}

.case-item {
  background: linear-gradient(135deg, rgba(230, 57, 70, 0.05), rgba(255, 209, 102, 0.08));
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  border-left: 4px solid var(--accent-warm);
  transition: all var(--transition);
}

.case-item:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-sm);
}

#cases blockquote {
  background: var(--bg);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  margin: 1rem 0;
  border-left: 4px solid var(--primary);
  position: relative;
  transition: all var(--transition);
}

#cases blockquote::before {
  content: '\201C';
  position: absolute;
  top: 0.25rem;
  left: 0.75rem;
  font-size: 2.5rem;
  color: var(--primary);
  opacity: 0.2;
  font-family: Georgia, serif;
  line-height: 1;
}

#cases blockquote:hover {
  background: rgba(230, 57, 70, 0.04);
  transform: translateX(4px);
}

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

/* ===== 新闻中心 ===== */
#news {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

#news:hover {
  box-shadow: var(--shadow-md);
}

#news article {
  background: var(--bg);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  border: 1px solid var(--border);
  transition: all var(--transition);
}

#news article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(230, 57, 70, 0.2);
}

#news article h3 {
  margin-top: 0;
  color: var(--text);
}

#news article time {
  display: inline-block;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

#news article a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--primary);
  transition: gap var(--transition), color var(--transition);
}

#news article a::after {
  content: '→';
  transition: transform var(--transition);
}

#news article a:hover {
  gap: 0.6rem;
  color: var(--primary-dark);
}

#news article a:hover::after {
  transform: translateX(4px);
}

/* ===== 技术文章 ===== */
#articles {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

#articles:hover {
  box-shadow: var(--shadow-md);
}

#articles article {
  background: var(--bg);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  border: 1px solid var(--border);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

#articles article::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 0;
  background: linear-gradient(180deg, var(--primary), var(--primary-light));
  transition: height var(--transition);
}

#articles article:hover::before {
  height: 100%;
}

#articles article:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(230, 57, 70, 0.2);
}

#articles article h3 {
  margin-top: 0;
  color: var(--text);
}

#articles article time {
  display: inline-block;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

#articles article a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--primary);
  transition: gap var(--transition), color var(--transition);
}

#articles article a::after {
  content: '→';
  transition: transform var(--transition);
}

#articles article a:hover {
  gap: 0.6rem;
  color: var(--primary-dark);
}

#articles article a:hover::after {
  transform: translateX(4px);
}

/* ===== FAQ ===== */
#faq {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

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

#faq details {
  background: var(--bg);
  border-radius: var(--radius-md);
  margin-bottom: 0.75rem;
  border: 1px solid var(--border);
  overflow: hidden;
  transition: all var(--transition);
}

#faq details[open] {
  border-color: rgba(230, 57, 70, 0.3);
  box-shadow: 0 4px 16px rgba(230, 57, 70, 0.08);
}

#faq details:hover {
  border-color: rgba(230, 57, 70, 0.2);
}

#faq summary {
  padding: 1rem 1.25rem;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  color: var(--text);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  transition: background var(--transition);
  user-select: none;
}

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

#faq summary::before {
  content: '+';
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(230, 57, 70, 0.1);
  color: var(--primary);
  font-weight: 700;
  font-size: 1rem;
  flex-shrink: 0;
  transition: all var(--transition);
}

#faq details[open] summary::before {
  content: '−';
  background: var(--primary);
  color: #fff;
  transform: rotate(180deg);
}

#faq summary:hover {
  background: rgba(230, 57, 70, 0.04);
}

#faq details p {
  padding: 0 1.25rem 1.25rem 3.25rem;
  margin: 0;
  color: var(--text-secondary);
  animation: fadeIn 0.3s ease-out;
}

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

/* ===== HowTo ===== */
#howto {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

#howto:hover {
  box-shadow: var(--shadow-md);
}

#howto ol {
  counter-reset: step;
  margin: 1rem 0;
}

#howto ol li {
  counter-increment: step;
  position: relative;
  padding-left: 3.25rem;
  margin-bottom: 1.25rem;
  color: var(--text-secondary);
  min-height: 2rem;
}

#howto ol li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0.15em;
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(230, 57, 70, 0.3);
}

#howto ol li strong {
  color: var(--text);
}

#howto ul {
  margin: 1rem 0;
  padding-left: 1.25rem;
}

#howto ul li {
  position: relative;
  padding-left: 1rem;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

#howto ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--secondary-light);
}

/* ===== 联系我们 ===== */
#contact {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

#contact:hover {
  box-shadow: var(--shadow-md);
}

.contact-info {
  background: linear-gradient(135deg, rgba(230, 57, 70, 0.04), rgba(29, 53, 87, 0.04));
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.contact-info p {
  margin-bottom: 0.6rem;
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.contact-info p strong {
  color: var(--text);
  display: inline-block;
  min-width: 6em;
}

.contact-info a {
  color: var(--primary);
  font-weight: 600;
}

/* ===== 网站地图 ===== */
#sitemap {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: box-shadow var(--transition);
}

#sitemap:hover {
  box-shadow: var(--shadow-md);
}

#sitemap ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  margin: 1rem 0 1.5rem;
}

#sitemap ul li a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  position: relative;
  transition: color var(--transition);
}

#sitemap ul li a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width var(--transition);
}

#sitemap ul li a:hover {
  color: var(--primary);
}

#sitemap ul li a:hover::after {
  width: 100%;
}

/* ===== 页脚 ===== */
footer {
  background: linear-gradient(135deg, #1d3557, #16213e);
  color: rgba(255, 255, 255, 0.8);
  padding: 2.5rem 1.5rem;
  text-align: center;
  margin-top: 2rem;
}

footer p {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

footer a {
  color: rgba(255, 255, 255, 0.9);
  font-weight: 600;
  transition: color var(--transition);
}

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

/* ===== 返回顶部 ===== */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-size: 1.25rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(230, 57, 70, 0.4);
  transition: all var(--transition);
  z-index: 999;
  opacity: 0.85;
}

.back-to-top:hover {
  background: var(--primary-dark);
  transform: translateY(-4px) scale(1.08);
  box-shadow: 0 8px 28px rgba(230, 57, 70, 0.55);
  opacity: 1;
  color: #fff;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  #hero {
    grid-template-columns: 1fr;
    padding: 2.5rem 2rem;
  }

  .hero-slider {
    max-width: 600px;
    margin: 0 auto;
  }

  .header-inner {
    gap: 1rem;
  }

  form[role="search"] input {
    width: 140px;
  }
}

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

  .header-inner {
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
  }

  .header-inner > a:first-child {
    display: flex;
    justify-content: center;
  }

  nav[aria-label="主导航"] ul {
    justify-content: center;
    gap: 0.15rem;
  }

  nav[aria-label="主导航"] a {
    font-size: 0.82rem;
    padding: 0.35rem 0.65rem;
  }

  form[role="search"] {
    width: 100%;
  }

  form[role="search"] input {
    width: 100%;
    flex: 1;
  }

  main {
    padding: 0.75rem 1rem 2rem;
  }

  #hero {
    padding: 2rem 1.25rem;
    border-radius: var(--radius-md);
  }

  .hero-content h1 {
    font-size: 1.5rem;
  }

  .hero-content p {
    font-size: 0.95rem;
  }

  .btn-primary,
  .btn-secondary {
    padding: 0.65rem 1.5rem;
    font-size: 0.9rem;
  }

  #brand,
  #products,
  #solutions,
  #cases,
  #news,
  #articles,
  #faq,
  #howto,
  #contact,
  #sitemap {
    padding: 1.5rem 1.25rem;
    border-radius: var(--radius-md);
  }

  h2 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
  }

  h3 {
    font-size: 1.05rem;
  }

  #products ul,
  #solutions ul {
    grid-template-columns: 1fr;
  }

  #faq details p {
    padding-left: 1.25rem;
  }

  #howto ol li {
    padding-left: 2.75rem;
  }

  #howto ol li::before {
    width: 1.75rem;
    height: 1.75rem;
    font-size: 0.78rem;
  }

  .back-to-top {
    bottom: 1.25rem;
    right: 1.25rem;
    width: 42px;
    height: 42px;
    font-size: 1.1rem;
  }

  footer {
    padding: 1.75rem 1rem;
  }
}

@media (max-width: 480px) {
  html {
    font-size: 14px;
  }

  .header-inner svg {
    width: 150px;
    height: 40px;
  }

  nav[aria-label="主导航"] a {
    font-size: 0.78rem;
    padding: 0.3rem 0.5rem;
  }

  section {
    margin-bottom: 2.5rem;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
    justify-content: center;
  }
}

/* ===== 滚动动画增强 ===== */
@media (prefers-reduced-motion: no-preference) {
  section {
    animation: fadeInUp 0.7s ease-out both;
  }

  #hero {
    animation: heroGlow 4s ease-in-out infinite alternate;
  }

  @keyframes heroGlow {
    from {
      box-shadow: 0 16px 48px rgba(230, 57, 70, 0.25);
    }
    to {
      box-shadow: 0 16px 48px rgba(29, 53, 87, 0.35);
    }
  }
}

@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;
  }
}

/* ===== 滚动条美化 ===== */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg);
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, var(--primary), var(--secondary));
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-dark);
}

/* ===== 选中文本 ===== */
::selection {
  background: rgba(230, 57, 70, 0.25);
  color: var(--text);
}

/* ===== 焦点可见 ===== */
:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: 4px;
}