/* ============================================================
   Kunming Lishidong Information Technology Co., Ltd.
   Dark Theme Stylesheet
   ============================================================ */

/* ---------- CSS Variables & Reset ---------- */
:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: #1a1a28;
  --bg-hover: #222236;
  --text-primary: #e8e8f0;
  --text-secondary: #a0a0b8;
  --text-muted: #6b6b80;
  --accent-1: #00d4ff;
  --accent-2: #7c3aed;
  --accent-3: #06d6a0;
  --accent-gradient: linear-gradient(135deg, #00d4ff, #7c3aed);
  --accent-gradient-2: linear-gradient(135deg, #06d6a0, #00d4ff);
  --border-color: #2a2a3e;
  --border-light: #3a3a50;
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 20px rgba(0, 212, 255, 0.15);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --font-sans: 'Segoe UI', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
  --max-width: 1200px;
  --header-height: 72px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--border-light); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ---------- Language Hidden Class ---------- */
.lang-en, .lang-zh {
  display: inline;
}
body.lang-active-zh .lang-en {
  display: none;
}
body.lang-active-zh .lang-zh {
  display: inline;
}
body:not(.lang-active-zh) .lang-zh {
  display: none;
}

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3.5vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.75rem); }
h4 { font-size: 1.25rem; }

p { margin-bottom: 1rem; }

a {
  color: var(--accent-1);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover { color: #66e5ff; }

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

/* ---------- Container ---------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Section ---------- */
.section {
  padding: 100px 0;
}
.section-dark {
  background: var(--bg-secondary);
}
.section-label {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 3px;
  color: var(--accent-1);
  margin-bottom: 12px;
}
.section-title {
  margin-bottom: 16px;
}
.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 600px;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  font-family: var(--font-sans);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
}
.btn-primary {
  background: var(--accent-gradient);
  color: #fff;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
  color: #fff;
}
.btn-outline {
  background: transparent;
  border: 2px solid var(--border-light);
  color: var(--text-primary);
}
.btn-outline:hover {
  border-color: var(--accent-1);
  color: var(--accent-1);
  transform: translateY(-2px);
}
.btn-sm {
  padding: 10px 20px;
  font-size: 0.9rem;
}

/* ---------- Language Toggle ---------- */
.lang-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1001;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 50px;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  transition: all var(--transition);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(12px);
}
.lang-toggle:hover {
  border-color: var(--accent-1);
  box-shadow: var(--shadow-glow);
}
.lang-toggle .indicator {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  color: #fff;
  transition: var(--transition);
}

/* ---------- Header / Nav ---------- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  z-index: 1000;
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  transition: all var(--transition);
}
.header.scrolled {
  background: rgba(10, 10, 15, 0.95);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
}
.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--accent-gradient);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 0.9rem;
  color: #fff;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}
.nav-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color var(--transition);
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-gradient);
  transition: width var(--transition);
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
}
.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
}
.mobile-menu-btn span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* ---------- Hero Section ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: var(--header-height);
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero-bg .grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
}
.hero-bg .glow-1 {
  position: absolute;
  top: -20%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.08), transparent 70%);
  border-radius: 50%;
  animation: float-slow 8s ease-in-out infinite alternate;
}
.hero-bg .glow-2 {
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(124, 58, 237, 0.06), transparent 70%);
  border-radius: 50%;
  animation: float-slow 10s ease-in-out infinite alternate-reverse;
}
@keyframes float-slow {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(30px, -30px) scale(1.1); }
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: rgba(0, 212, 255, 0.1);
  border: 1px solid rgba(0, 212, 255, 0.2);
  border-radius: 50px;
  font-size: 0.85rem;
  color: var(--accent-1);
  margin-bottom: 24px;
}
.hero h1 {
  margin-bottom: 24px;
}
.hero h1 .highlight {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 40px;
  max-width: 600px;
}
.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* ---------- Services Grid ---------- */
.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 48px;
}
.service-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px 28px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--accent-gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}
.service-card:hover {
  border-color: var(--border-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.service-card:hover::before {
  transform: scaleX(1);
}
.service-icon {
  width: 52px;
  height: 52px;
  background: rgba(0, 212, 255, 0.1);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
}
.service-card h3 {
  margin-bottom: 12px;
}
.service-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 0;
}

/* ---------- About Section ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  margin-top: 48px;
}
.about-visual {
  position: relative;
}
.about-visual .code-block {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.8;
  color: var(--text-secondary);
  overflow-x: auto;
}
.code-block .keyword { color: #7c3aed; }
.code-block .string { color: #06d6a0; }
.code-block .comment { color: var(--text-muted); font-style: italic; }
.code-block .function { color: #00d4ff; }
.stats-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 32px;
}
.stat-item {
  text-align: center;
  padding: 20px 12px;
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}
.stat-number {
  font-size: 2rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.stat-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ---------- Features ---------- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin-top: 48px;
}
.feature-item {
  display: flex;
  gap: 16px;
  padding: 24px;
  background: var(--bg-card);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  transition: all var(--transition);
}
.feature-item:hover {
  border-color: var(--border-light);
  transform: translateY(-2px);
}
.feature-check {
  width: 28px;
  height: 28px;
  min-width: 28px;
  background: rgba(6, 214, 160, 0.15);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-3);
  font-weight: bold;
}
.feature-item h4 {
  font-size: 1.05rem;
  margin-bottom: 6px;
}
.feature-item p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 0;
}

/* ---------- Contact Section ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  margin-top: 48px;
}
.contact-info-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.contact-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.contact-item-icon {
  width: 44px;
  height: 44px;
  min-width: 44px;
  background: rgba(0, 212, 255, 0.1);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}
.contact-item h4 {
  font-size: 1rem;
  margin-bottom: 4px;
}
.contact-item p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 0;
}
.contact-item a {
  color: var(--text-secondary);
}
.contact-item a:hover {
  color: var(--accent-1);
}
.contact-form {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px;
}
.form-group {
  margin-bottom: 20px;
}
.form-group label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-secondary);
}
.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 14px 16px;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  transition: border-color var(--transition);
}
.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--accent-1);
  box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.1);
}
.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

/* ---------- Team Section ---------- */
.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px;
  margin-top: 48px;
}
.team-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px 24px;
  text-align: center;
  transition: all var(--transition);
}
.team-card:hover {
  border-color: var(--border-light);
  transform: translateY(-4px);
}
.team-avatar {
  width: 80px;
  height: 80px;
  margin: 0 auto 16px;
  background: var(--accent-gradient);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: #fff;
}
.team-card h4 {
  margin-bottom: 4px;
}
.team-role {
  color: var(--accent-1);
  font-size: 0.85rem;
  font-weight: 500;
}

/* ---------- Policy / Terms Pages ---------- */
.policy-page {
  padding-top: calc(var(--header-height) + 60px);
  padding-bottom: 80px;
}
.policy-page h1 {
  margin-bottom: 8px;
}
.policy-date {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 40px;
}
.policy-content h2 {
  font-size: 1.5rem;
  margin-top: 40px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}
.policy-content h3 {
  font-size: 1.2rem;
  margin-top: 28px;
  margin-bottom: 12px;
}
.policy-content p {
  margin-bottom: 16px;
  color: var(--text-secondary);
}
.policy-content ul, .policy-content ol {
  margin: 16px 0;
  padding-left: 24px;
  color: var(--text-secondary);
}
.policy-content li {
  margin-bottom: 8px;
}
.policy-content strong {
  color: var(--text-primary);
}

/* ---------- Page Header ---------- */
.page-header {
  padding-top: calc(var(--header-height) + 60px);
  padding-bottom: 60px;
  text-align: center;
  position: relative;
}
.page-header .bg-glow {
  position: absolute;
  top: -50%;
  left: 50%;
  transform: translateX(-50%);
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.05), transparent 70%);
  pointer-events: none;
}
.page-header h1 {
  position: relative;
  z-index: 1;
}
.page-header p {
  position: relative;
  z-index: 1;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 16px auto 0;
}

/* ---------- Footer ---------- */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 64px 0 32px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}
.footer-brand p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 16px;
}
.footer h4 {
  font-size: 1rem;
  margin-bottom: 20px;
}
.footer-links {
  list-style: none;
}
.footer-links li {
  margin-bottom: 10px;
}
.footer-links a {
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: color var(--transition);
}
.footer-links a:hover {
  color: var(--accent-1);
}
.footer-bottom {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- Page Specific ---------- */
body.page-home .header {
  background: transparent;
  border-bottom-color: transparent;
}
body.page-home .header.scrolled {
  background: rgba(10, 10, 15, 0.95);
  border-bottom-color: var(--border-color);
}

/* ---------- Animations ---------- */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- CTA Section ---------- */
.cta-section {
  text-align: center;
  padding: 100px 0;
  background: var(--bg-secondary);
  position: relative;
  overflow: hidden;
}
.cta-section .glow {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(124, 58, 237, 0.06), transparent 70%);
  pointer-events: none;
}
.cta-section h2 {
  margin-bottom: 16px;
  position: relative;
  z-index: 1;
}
.cta-section p {
  color: var(--text-secondary);
  max-width: 500px;
  margin: 0 auto 32px;
  position: relative;
  z-index: 1;
}
.cta-section .btn {
  position: relative;
  z-index: 1;
}

/* ---------- Mobile Responsive ---------- */
@media (max-width: 968px) {
  .about-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .contact-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--bg-secondary);
    flex-direction: column;
    padding: 100px 32px;
    gap: 24px;
    transition: right var(--transition);
    border-left: 1px solid var(--border-color);
    z-index: 999;
  }
  .nav-links.open {
    right: 0;
  }
  .mobile-menu-btn {
    display: flex;
  }
  .lang-toggle {
    top: 12px;
    right: 12px;
    padding: 6px 12px;
    font-size: 0.8rem;
  }
  .hero h1 {
    font-size: clamp(1.6rem, 6vw, 2.5rem);
  }
  .stats-row {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
  .services-grid {
    grid-template-columns: 1fr;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
}