:root {
  --primary: #1a3a5c;
  --primary-light: #2a5a8c;
  --primary-dark: #0f2440;
  --accent: #4a9eff;
  --accent-hover: #6bb3ff;
  --accent-glow: rgba(74, 158, 255, 0.3);
  --gradient-start: #1a3a5c;
  --gradient-mid: #2a5a8c;
  --gradient-end: #4a9eff;
  --bg-body: #f0f4f8;
  --bg-card: #ffffff;
  --bg-card-hover: #f8fafc;
  --bg-glass: rgba(255, 255, 255, 0.72);
  --bg-glass-border: rgba(255, 255, 255, 0.45);
  --bg-header: rgba(255, 255, 255, 0.82);
  --bg-footer: #0f2440;
  --bg-input: #ffffff;
  --text-primary: #1a2a3a;
  --text-secondary: #4a5a6a;
  --text-muted: #7a8a9a;
  --text-inverse: #ffffff;
  --text-link: #2a5a8c;
  --text-link-hover: #4a9eff;
  --border-color: #dce4ec;
  --border-light: #eaf0f6;
  --shadow-sm: 0 1px 3px rgba(26, 58, 92, 0.06);
  --shadow-md: 0 4px 16px rgba(26, 58, 92, 0.1);
  --shadow-lg: 0 8px 32px rgba(26, 58, 92, 0.14);
  --shadow-xl: 0 16px 48px rgba(26, 58, 92, 0.18);
  --shadow-glow: 0 0 24px rgba(74, 158, 255, 0.25);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-full: 9999px;
  --transition-fast: 0.18s ease;
  --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", monospace;
  --max-width: 1200px;
  --header-height: 68px;
}

[data-theme="dark"] {
  --primary: #4a9eff;
  --primary-light: #6bb3ff;
  --primary-dark: #0a1628;
  --accent: #4a9eff;
  --accent-hover: #6bb3ff;
  --accent-glow: rgba(74, 158, 255, 0.2);
  --gradient-start: #0a1628;
  --gradient-mid: #1a3a5c;
  --gradient-end: #2a5a8c;
  --bg-body: #0d1520;
  --bg-card: #14202e;
  --bg-card-hover: #1a2a3c;
  --bg-glass: rgba(20, 32, 46, 0.78);
  --bg-glass-border: rgba(74, 158, 255, 0.12);
  --bg-header: rgba(13, 21, 32, 0.85);
  --bg-footer: #080e16;
  --bg-input: #1a2a3c;
  --text-primary: #e8eef4;
  --text-secondary: #a0b0c0;
  --text-muted: #6a7a8a;
  --text-inverse: #0d1520;
  --text-link: #6bb3ff;
  --text-link-hover: #8ec5ff;
  --border-color: #1e3044;
  --border-light: #162636;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 24px rgba(74, 158, 255, 0.15);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 20px);
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

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

body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  background:
    radial-gradient(ellipse 80% 60% at 10% 20%, rgba(74, 158, 255, 0.06), transparent),
    radial-gradient(ellipse 60% 50% at 90% 80%, rgba(42, 90, 140, 0.05), transparent);
}

[data-theme="dark"] body::before {
  background:
    radial-gradient(ellipse 80% 60% at 10% 20%, rgba(74, 158, 255, 0.04), transparent),
    radial-gradient(ellipse 60% 50% at 90% 80%, rgba(42, 90, 140, 0.06), transparent);
}

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

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

a:hover {
  color: var(--text-link-hover);
}

ul, ol {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  font-size: inherit;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

/* ========== HEADER ========== */
#site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  height: var(--header-height);
  background: var(--bg-header);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--border-light);
  transition: background var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

#site-header.scrolled {
  box-shadow: var(--shadow-md);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 20px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  text-decoration: none;
  transition: transform var(--transition-fast);
}

.logo:hover {
  transform: scale(1.03);
}

.logo svg {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(26, 58, 92, 0.2);
}

.logo-text {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: 1px;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

#main-nav {
  flex: 1;
  display: flex;
  justify-content: center;
}

#main-nav ul {
  display: flex;
  gap: 4px;
  align-items: center;
}

#main-nav a {
  display: block;
  padding: 8px 14px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-full);
  transition: color var(--transition-fast), background var(--transition-fast), transform var(--transition-fast);
  white-space: nowrap;
  position: relative;
}

#main-nav a:hover {
  color: var(--primary);
  background: rgba(74, 158, 255, 0.08);
  transform: translateY(-1px);
}

#main-nav a::after {
  content: "";
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 20px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  transition: transform var(--transition-base);
}

#main-nav a:hover::after {
  transform: translateX(-50%) scaleX(1);
}

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

#site-search {
  display: flex;
  align-items: center;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  overflow: hidden;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

#site-search:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

#site-search input {
  width: 160px;
  padding: 8px 14px;
  border: none;
  background: transparent;
  color: var(--text-primary);
  font-size: 0.85rem;
  outline: none;
}

#site-search input::placeholder {
  color: var(--text-muted);
  font-size: 0.82rem;
}

#site-search button {
  padding: 8px 14px;
  background: linear-gradient(135deg, var(--gradient-mid), var(--gradient-end));
  color: #fff;
  font-size: 0.82rem;
  font-weight: 600;
  border-radius: 0 var(--radius-full) var(--radius-full) 0;
  transition: opacity var(--transition-fast), transform var(--transition-fast);
}

#site-search button:hover {
  opacity: 0.9;
}

#site-search button:active {
  transform: scale(0.96);
}

#theme-toggle,
#menu-toggle {
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  font-size: 1.1rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  transition: background var(--transition-fast), transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}

#theme-toggle:hover,
#menu-toggle:hover {
  background: var(--bg-card-hover);
  transform: scale(1.08);
  box-shadow: var(--shadow-sm);
}

#theme-toggle:active,
#menu-toggle:active {
  transform: scale(0.95);
}

#menu-toggle {
  display: none;
}

/* ========== HERO ========== */
#hero {
  position: relative;
  overflow: hidden;
  padding: 80px 24px 70px;
  background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-mid) 45%, var(--gradient-end) 100%);
  color: #fff;
  isolation: isolate;
}

#hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 80% at 15% 30%, rgba(255, 255, 255, 0.1), transparent),
    radial-gradient(ellipse 50% 60% at 85% 70%, rgba(74, 158, 255, 0.2), transparent);
  pointer-events: none;
  z-index: 0;
}

#hero::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 100%;
  height: 60px;
  background: var(--bg-body);
  clip-path: ellipse(75% 100% at 50% 100%);
  z-index: 1;
  transition: background var(--transition-base);
}

.hero-inner {
  position: relative;
  z-index: 2;
  max-width: var(--max-width);
  margin: 0 auto;
  text-align: center;
}

#hero h1 {
  font-size: clamp(1.6rem, 4.5vw, 2.8rem);
  font-weight: 800;
  line-height: 1.35;
  margin-bottom: 22px;
  letter-spacing: 0.5px;
  text-shadow: 0 2px 16px rgba(0, 0, 0, 0.15);
  animation: heroFadeIn 0.8s ease-out both;
}

.hero-lead {
  max-width: 820px;
  margin: 0 auto 36px;
  font-size: clamp(0.92rem, 1.8vw, 1.08rem);
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.88);
  animation: heroFadeIn 0.8s ease-out 0.15s both;
}

@keyframes heroFadeIn {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
  animation: heroFadeIn 0.8s ease-out 0.3s both;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 36px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--primary-dark);
  background: #fff;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
  transition: transform var(--transition-base), box-shadow var(--transition-base), background var(--transition-fast);
  text-decoration: none;
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.25);
  background: #f0f6ff;
  color: var(--primary-dark);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 36px;
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
  border: 1.5px solid rgba(255, 255, 255, 0.4);
  border-radius: var(--radius-full);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: transform var(--transition-base), background var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-base);
  text-decoration: none;
}

.btn-secondary:hover {
  transform: translateY(-3px);
  background: rgba(255, 255, 255, 0.22);
  border-color: rgba(255, 255, 255, 0.7);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.2);
  color: #fff;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
  animation: heroFadeIn 0.8s ease-out 0.45s both;
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  min-width: 90px;
}

.stat-num {
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.5px;
  background: linear-gradient(180deg, #fff, rgba(255, 255, 255, 0.75));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.72);
  font-weight: 500;
  letter-spacing: 0.5px;
}

/* ========== BREADCRUMB ========== */
#breadcrumb {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px 0;
}

#breadcrumb ol {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.84rem;
  color: var(--text-muted);
  flex-wrap: wrap;
}

#breadcrumb li {
  display: flex;
  align-items: center;
  gap: 6px;
}

#breadcrumb li + li::before {
  content: "/";
  color: var(--border-color);
  font-weight: 300;
}

#breadcrumb a {
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

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

#breadcrumb [aria-current="page"] {
  color: var(--text-muted);
  font-weight: 500;
}

/* ========== SECTIONS COMMON ========== */
main > section:not(#hero):not(#breadcrumb) {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 56px 24px;
}

main > section:not(#hero):not(#breadcrumb) h2 {
  font-size: clamp(1.35rem, 3vw, 1.85rem);
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 24px;
  line-height: 1.4;
  position: relative;
  padding-left: 18px;
}

main > section:not(#hero):not(#breadcrumb) h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.15em;
  bottom: 0.15em;
  width: 5px;
  border-radius: 3px;
  background: linear-gradient(180deg, var(--gradient-mid), var(--gradient-end));
}

main > section:not(#hero):not(#breadcrumb) h3 {
  font-size: clamp(1.1rem, 2.2vw, 1.3rem);
  font-weight: 700;
  color: var(--text-primary);
  margin: 32px 0 12px;
  line-height: 1.45;
}

main > section:not(#hero):not(#breadcrumb) h4 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin: 22px 0 8px;
}

main > section:not(#hero):not(#breadcrumb) p {
  color: var(--text-secondary);
  margin-bottom: 14px;
  line-height: 1.85;
  font-size: 0.95rem;
}

main > section:not(#hero):not(#breadcrumb) ul,
main > section:not(#hero):not(#breadcrumb) ol {
  margin: 12px 0 18px;
  padding-left: 0;
}

main > section:not(#hero):not(#breadcrumb) ul li,
main > section:not(#hero):not(#breadcrumb) ol li {
  position: relative;
  padding: 6px 0 6px 26px;
  color: var(--text-secondary);
  font-size: 0.93rem;
  line-height: 1.75;
}

main > section:not(#hero):not(#breadcrumb) ul li::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 15px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--gradient-mid), var(--gradient-end));
  opacity: 0.7;
}

main > section:not(#hero):not(#breadcrumb) ol {
  counter-reset: item;
}

main > section:not(#hero):not(#breadcrumb) ol li::before {
  content: counter(item);
  counter-increment: item;
  position: absolute;
  left: 0;
  top: 8px;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.72rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, var(--gradient-mid), var(--gradient-end));
  border-radius: 50%;
  opacity: 0.85;
}

main > section:not(#hero):not(#breadcrumb) strong {
  color: var(--text-primary);
  font-weight: 600;
}

/* ========== BRAND INTRO ========== */
#brand-intro {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  margin-top: 24px !important;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

/* ========== PRODUCTS ========== */
#products {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

#products ul li strong {
  color: var(--primary);
}

/* ========== SOLUTIONS ========== */
#solutions {
  background: linear-gradient(135deg, rgba(74, 158, 255, 0.04), rgba(42, 90, 140, 0.06));
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base);
}

[data-theme="dark"] #solutions {
  background: linear-gradient(135deg, rgba(74, 158, 255, 0.06), rgba(42, 90, 140, 0.1));
}

/* ========== CASES ========== */
#cases {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

#cases blockquote {
  position: relative;
  margin: 16px 0;
  padding: 20px 24px 20px 48px;
  background: linear-gradient(135deg, rgba(74, 158, 255, 0.06), rgba(42, 90, 140, 0.04));
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  transition: transform var(--transition-base), box-shadow var(--transition-base), background var(--transition-base);
}

#cases blockquote:hover {
  transform: translateX(6px);
  box-shadow: var(--shadow-md);
}

#cases blockquote::before {
  content: "\201C";
  position: absolute;
  left: 12px;
  top: 6px;
  font-size: 2.8rem;
  line-height: 1;
  color: var(--accent);
  opacity: 0.35;
  font-family: Georgia, serif;
}

#cases blockquote p {
  margin: 0;
  font-style: italic;
  color: var(--text-secondary);
  font-size: 0.93rem;
}

/* ========== ARTICLES ========== */
#articles {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

.article-card {
  position: relative;
  padding: 24px;
  margin-bottom: 18px;
  background: var(--bg-body);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base), background var(--transition-base);
  overflow: hidden;
}

.article-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--gradient-mid), var(--gradient-end));
  opacity: 0;
  transition: opacity var(--transition-base);
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(74, 158, 255, 0.25);
  background: var(--bg-card);
}

.article-card:hover::before {
  opacity: 1;
}

.article-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0 0 8px;
  line-height: 1.5;
  transition: color var(--transition-fast);
}

.article-card:hover h3 {
  color: var(--accent);
}

.article-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.article-summary {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 14px;
}

.read-more {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent);
  transition: gap var(--transition-fast), color var(--transition-fast);
}

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

.read-more:hover {
  gap: 8px;
  color: var(--text-link-hover);
}

.read-more:hover::after {
  transform: translateX(3px);
}

/* ========== HOWTO ========== */
#howto {
  background: linear-gradient(135deg, rgba(74, 158, 255, 0.04), rgba(42, 90, 140, 0.06));
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base);
}

[data-theme="dark"] #howto {
  background: linear-gradient(135deg, rgba(74, 158, 255, 0.06), rgba(42, 90, 140, 0.1));
}

/* ========== FAQ ========== */
#faq {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

#faq details {
  margin-bottom: 12px;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  background: var(--bg-body);
  overflow: hidden;
  transition: border-color var(--transition-base), box-shadow var(--transition-base), background var(--transition-base);
}

#faq details:hover {
  border-color: rgba(74, 158, 255, 0.3);
  box-shadow: var(--shadow-sm);
}

#faq details[open] {
  border-color: rgba(74, 158, 255, 0.35);
  box-shadow: var(--shadow-md);
  background: var(--bg-card);
}

#faq summary {
  position: relative;
  padding: 16px 48px 16px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  transition: color var(--transition-fast), background var(--transition-fast);
  user-select: none;
  -webkit-user-select: none;
}

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

#faq summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.3rem;
  font-weight: 300;
  color: var(--accent);
  transition: transform var(--transition-base), color var(--transition-fast);
  line-height: 1;
}

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

#faq summary:hover {
  color: var(--accent);
  background: rgba(74, 158, 255, 0.04);
}

#faq details p {
  padding: 0 20px 18px;
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.8;
  animation: faqSlideDown 0.3s ease-out;
}

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

/* ========== KNOWLEDGE ========== */
#knowledge {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

/* ========== CONTACT ========== */
#contact {
  background: linear-gradient(135deg, rgba(74, 158, 255, 0.04), rgba(42, 90, 140, 0.06));
  border-radius: var(--radius-xl);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base);
}

[data-theme="dark"] #contact {
  background: linear-gradient(135deg, rgba(74, 158, 255, 0.06), rgba(42, 90, 140, 0.1));
}

.contact-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.contact-list li {
  padding: 14px 18px !important;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  font-size: 0.9rem;
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.contact-list li::before {
  display: none !important;
}

.contact-list li:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: rgba(74, 158, 255, 0.25);
}

.contact-list li strong {
  color: var(--text-primary);
  font-weight: 600;
  white-space: nowrap;
}

.contact-list li a {
  word-break: break-all;
}

/* ========== SITEMAP ========== */
#sitemap {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

.sitemap-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 12px;
}

.sitemap-list li {
  padding: 0 !important;
}

.sitemap-list li::before {
  display: none !important;
}

.sitemap-list a {
  display: inline-block;
  padding: 8px 20px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-body);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
}

.sitemap-list a:hover {
  color: #fff;
  background: linear-gradient(135deg, var(--gradient-mid), var(--gradient-end));
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ========== LINKS ========== */
#links {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
  transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

.friend-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 12px;
}

.friend-links li {
  padding: 0 !important;
}

.friend-links li::before {
  display: none !important;
}

.friend-links a {
  display: inline-block;
  padding: 8px 20px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-body);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
}

.friend-links a:hover {
  color: #fff;
  background: linear-gradient(135deg, var(--gradient-mid), var(--gradient-end));
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ========== FOOTER ========== */
#site-footer {
  background: var(--bg-footer);
  color: rgba(255, 255, 255, 0.75);
  margin-top: 40px;
  transition: background var(--transition-base);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 48px 24px 32px;
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 40px;
}

.footer-brand h3 {
  font-size: 1.3rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 12px;
  background: linear-gradient(135deg, #fff, var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-brand p {
  font-size: 0.88rem;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.6);
}

.footer-nav h4,
.footer-contact h4 {
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 16px;
  position: relative;
  padding-bottom: 10px;
}

.footer-nav h4::after,
.footer-contact h4::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 28px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
}

.footer-nav ul li,
.footer-contact ul li {
  padding: 5px 0;
  font-size: 0.88rem;
  color: rgba(255, 255, 255, 0.6);
}

.footer-nav ul li::before,
.footer-contact ul li::before {
  display: none !important;
}

.footer-nav a {
  color: rgba(255, 255, 255, 0.6);
  transition: color var(--transition-fast), padding-left var(--transition-fast);
  position: relative;
}

.footer-nav a:hover {
  color: var(--accent);
  padding-left: 6px;
}

.footer-bottom {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 20px 24px 32px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  text-align: center;
}

.footer-bottom p {
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.45);
  margin-bottom: 6px;
  line-height: 1.7;
}

.footer-bottom a {
  color: rgba(255, 255, 255, 0.55);
  transition: color var(--transition-fast);
}

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

/* ========== PRIVACY / DISCLAIMER / COPYRIGHT ========== */
#privacy,
#disclaimer,
#copyright {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px;
  border-top: 1px solid var(--border-light);
  transition: border-color var(--transition-base);
}

#privacy h2,
#disclaimer h2,
#copyright h2 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 14px;
}

#privacy p,
#disclaimer p,
#copyright p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.8;
}

/* ========== BACK TO TOP ========== */
#back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  z-index: 900;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, var(--gradient-mid), var(--gradient-end));
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px) scale(0.9);
  transition: opacity var(--transition-base), visibility var(--transition-base), transform var(--transition-base), box-shadow var(--transition-base);
}

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

#back-to-top:hover {
  transform: translateY(-4px) scale(1.08);
  box-shadow: var(--shadow-xl), 0 0 32px rgba(74, 158, 255, 0.4);
}

#back-to-top:active {
  transform: translateY(-2px) scale(1.02);
}

/* ========== SCROLL ANIMATIONS ========== */
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1), transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* ========== RESPONSIVE ========== */
@media (max-width: 1024px) {
  .header-inner {
    padding: 0 16px;
    gap: 12px;
  }

  #main-nav ul {
    gap: 2px;
  }

  #main-nav a {
    padding: 7px 10px;
    font-size: 0.84rem;
  }

  #site-search input {
    width: 120px;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 58px;
  }

  .header-inner {
    padding: 0 14px;
  }

  .logo svg {
    width: 32px;
    height: 32px;
  }

  .logo-text {
    font-size: 1.1rem;
  }

  #main-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--bg-glass);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--bg-glass-border);
    padding: 12px 16px;
    transform: translateY(-120%);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition-base), opacity var(--transition-base), visibility var(--transition-base);
    z-index: 999;
    justify-content: flex-start;
  }

  #main-nav.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  #main-nav ul {
    flex-direction: column;
    width: 100%;
    gap: 2px;
  }

  #main-nav a {
    padding: 12px 16px;
    font-size: 0.95rem;
    border-radius: var(--radius-md);
    width: 100%;
  }

  #main-nav a::after {
    display: none;
  }

  #site-search {
    display: none;
  }

  #menu-toggle {
    display: flex;
  }

  #hero {
    padding: 50px 18px 50px;
  }

  #hero h1 {
    font-size: 1.4rem;
  }

  .hero-lead {
    font-size: 0.88rem;
    margin-bottom: 28px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
    gap: 12px;
    margin-bottom: 36px;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
    max-width: 300px;
    padding: 13px 28px;
    font-size: 0.95rem;
  }

  .hero-stats {
    gap: 24px;
  }

  .stat-item {
    min-width: 70px;
  }

  .stat-num {
    font-size: 1.5rem;
  }

  .stat-label {
    font-size: 0.75rem;
  }

  main > section:not(#hero):not(#breadcrumb) {
    padding: 36px 16px;
  }

  main > section:not(#hero):not(#breadcrumb) h2 {
    font-size: 1.25rem;
    padding-left: 14px;
  }

  main > section:not(#hero):not(#breadcrumb) h2::before {
    width: 4px;
  }

  main > section:not(#hero):not(#breadcrumb) h3 {
    font-size: 1.05rem;
    margin: 24px 0 10px;
  }

  .article-card {
    padding: 18px;
  }

  .article-card h3 {
    font-size: 1rem;
  }

  .contact-list {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 36px 16px 24px;
  }

  .footer-brand {
    grid-column: auto;
  }

  .footer-bottom {
    padding: 16px 16px 28px;
  }

  #back-to-top {
    bottom: 20px;
    right: 20px;
    width: 42px;
    height: 42px;
    font-size: 1.1rem;
  }

  #breadcrumb {
    padding: 12px 16px 0;
  }

  #privacy,
  #disclaimer,
  #copyright {
    padding: 28px 16px;
  }
}

@media (max-width: 480px) {
  #hero {
    padding: 40px 14px 40px;
  }

  #hero h1 {
    font-size: 1.2rem;
    line-height: 1.4;
  }

  .hero-lead {
    font-size: 0.84rem;
    line-height: 1.7;
  }

  .hero-stats {
    gap: 16px;
  }

  .stat-num {
    font-size: 1.3rem;
  }

  .stat-label {
    font-size: 0.7rem;
  }

  main > section:not(#hero):not(#breadcrumb) h2 {
    font-size: 1.15rem;
  }

  main > section:not(#hero):not(#breadcrumb) p {
    font-size: 0.88rem;
  }

  main > section:not(#hero):not(#breadcrumb) ul li,
  main > section:not(#hero):not(#breadcrumb) ol li {
    font-size: 0.86rem;
  }

  #faq summary {
    padding: 14px 40px 14px 16px;
    font-size: 0.88rem;
  }

  #faq details p {
    padding: 0 16px 16px;
    font-size: 0.84rem;
  }

  .sitemap-list a,
  .friend-links a {
    padding: 7px 16px;
    font-size: 0.82rem;
  }
}

/* ========== ACCESSIBILITY ========== */
@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;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}

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

::selection {
  background: rgba(74, 158, 255, 0.25);
  color: var(--text-primary);
}

/* ========== SCROLLBAR ========== */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

[data-theme="dark"] ::-webkit-scrollbar-thumb {
  background: #2a3a4a;
}

[data-theme="dark"] ::-webkit-scrollbar-thumb:hover {
  background: #3a4a5a;
}