/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Roboto', 'Helvetica Neue', sans-serif; font-size: 16px; line-height: 1.6; color: #212121; background: #F5F5F5; -webkit-font-smoothing: antialiased; }

/* CSS Variables */
:root {
  --primary: #4CAF50;
  --primary-dark: #388E3C;
  --primary-light: #81C784;
  --secondary: #FF9800;
  --accent: #00BCD4;
  --neutral-light: #F5F5F5;
  --neutral-dark: #212121;
  --neutral-mid: #757575;
  --white: #FFFFFF;
  --border: #E0E0E0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --font-sans: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Roboto', sans-serif;
}
::selection { background: var(--primary-light); color: var(--white); }

/* Skip Link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 0;
  z-index: 9999;
  padding: 8px 16px;
  background: var(--primary);
  color: var(--white);
  text-decoration: none;
  font-weight: bold;
  border-radius: 0 0 4px 0;
  transition: top 0.2s;
}
.skip-link:focus { top: 0; outline: 2px solid var(--secondary); }

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--white);
  border-bottom: 1px solid var(--border);
  padding: 0 16px;
  height: 56px;
  display: flex;
  align-items: center;
  box-shadow: var(--shadow-sm);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
}
.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
}
.logo-icon {
  display: inline-flex;
  align-items: center;
  gap: 2px;
}
.icon-grid {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 2px solid var(--primary);
  border-radius: 2px;
  position: relative;
}
.icon-grid::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 6px;
  height: 6px;
  background: var(--secondary);
  border-radius: 1px;
}
.icon-leaf {
  display: inline-block;
  width: 12px;
  height: 16px;
  background: var(--primary);
  border-radius: 50% 50% 0 50%;
  transform: rotate(10deg);
}
.logo-text {
  font-family: 'Montserrat', var(--font-sans);
  font-weight: 700;
  font-size: 20px;
  color: var(--neutral-dark);
  letter-spacing: 1px;
}

/* Nav Toggle */
.nav-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 6px;
  border-radius: 4px;
  transition: background 0.2s;
}
.nav-toggle:hover { background: var(--neutral-light); }
.nav-toggle:focus-visible { outline: 2px solid var(--secondary); }
.hamburger-line {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--neutral-dark);
  margin: 3px 0;
  transition: transform 0.3s, opacity 0.3s;
}
.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .hamburger-line:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* Side Nav */
.side-nav {
  position: fixed;
  top: 56px;
  left: 0;
  bottom: 0;
  width: 220px;
  background: var(--white);
  border-right: 1px solid var(--border);
  transform: translateX(-100%);
  transition: transform 0.3s ease;
  z-index: 999;
  overflow-y: auto;
  padding: 16px 0;
}
.side-nav[data-open] { transform: translateX(0); }
.nav-list {
  list-style: none;
  padding: 0;
}
.nav-link {
  display: block;
  padding: 12px 20px;
  color: var(--neutral-dark);
  text-decoration: none;
  font-weight: 500;
  font-size: 15px;
  border-left: 3px solid transparent;
  transition: background 0.2s, border-color 0.2s;
}
.nav-link:hover { background: var(--neutral-light); border-left-color: var(--primary); }
.nav-link[aria-current="page"] {
  background: rgba(76, 175, 80, 0.08);
  border-left-color: var(--primary);
  color: var(--primary-dark);
  font-weight: 700;
}
.side-nav .nav-link:focus-visible { outline: 2px solid var(--secondary); outline-offset: -2px; }

/* Customer Service Fab */
.customer-service-fab {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 1001;
}
.fab-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  background: var(--secondary);
  color: var(--white);
  border-radius: 50%;
  box-shadow: 0 4px 12px rgba(255,152,0,0.4);
  text-decoration: none;
  font-size: 24px;
  animation: fab-pulse 2s infinite;
  transition: transform 0.2s, box-shadow 0.2s;
}
.fab-link:hover { transform: scale(1.05); box-shadow: 0 6px 20px rgba(255,152,0,0.6); }
.fab-link:focus-visible { outline: 3px solid var(--primary); outline-offset: 4px; }
@keyframes fab-pulse {
  0%, 100% { box-shadow: 0 4px 12px rgba(255,152,0,0.4); }
  50% { box-shadow: 0 4px 24px rgba(255,152,0,0.7); }
}
.fab-icon { line-height: 1; }

/* Footer */
.site-footer {
  background: var(--neutral-dark);
  color: var(--white);
  padding: 32px 16px;
  margin-top: 48px;
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 24px;
}
.footer-brand { flex: 1 1 200px; }
.footer-logo { font-size: 20px; font-weight: 700; color: var(--primary); }
.footer-tagline { color: var(--neutral-mid); font-size: 14px; margin-top: 4px; }
.footer-links { display: flex; flex-direction: column; gap: 8px; }
.footer-link { color: var(--accent); text-decoration: none; font-size: 14px; transition: color 0.2s; }
.footer-link:hover { color: var(--primary-light); }
.footer-link:focus-visible { outline: 2px solid var(--secondary); outline-offset: 2px; }
.footer-contact { display: flex; flex-direction: column; gap: 4px; }
.footer-email { color: var(--white); font-size: 14px; }
.footer-service { color: var(--neutral-mid); font-size: 13px; }
.footer-legal { display: flex; flex-direction: column; gap: 4px; align-items: flex-end; font-size: 13px; color: var(--neutral-mid); }
.footer-icp { color: var(--neutral-mid); }

/* Utility */
.container { max-width: 1200px; margin: 0 auto; padding: 0 16px; }
.btn-primary {
  display: inline-block;
  padding: 12px 24px;
  background: var(--primary);
  color: var(--white);
  font-weight: 700;
  text-decoration: none;
  border-radius: 4px;
  border: none;
  cursor: pointer;
  transition: background 0.2s, box-shadow 0.2s;
}
.btn-primary:hover { background: var(--primary-dark); box-shadow: var(--shadow-md); }
.btn-primary:focus-visible { outline: 2px solid var(--secondary); outline-offset: 2px; }
.card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s;
}
.card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }

/* Image placeholder base */
.img-placeholder {
  background: var(--neutral-light);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 200px;
  color: var(--neutral-mid);
  font-size: 14px;
  border: 1px dashed var(--border);
  border-radius: 4px;
}
.img-scene { background: linear-gradient(135deg, var(--primary-light), var(--accent)); }

/* Responsive */
@media (min-width: 768px) {
  .nav-toggle { display: none; }
  .side-nav { transform: translateX(0); position: fixed; }
  .site-header { padding-left: 236px; }
  .customer-service-fab { bottom: 32px; right: 32px; }
  .footer-inner { flex-wrap: nowrap; }
}
@media (max-width: 767px) {
  .side-nav { width: 100%; }
  .site-footer .footer-legal { align-items: flex-start; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
  .fab-link { animation: none; }
}

/* Focus visible */
:focus-visible { outline: 2px solid var(--secondary); outline-offset: 2px; }
:focus:not(:focus-visible) { outline: none; }

/* Back to top (added by JS) */
.back-to-top {
  position: fixed;
  bottom: 100px;
  right: 24px;
  z-index: 1000;
  width: 40px;
  height: 40px;
  background: var(--primary);
  color: var(--white);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.3s, visibility 0.3s, transform 0.3s, background 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  box-shadow: var(--shadow-sm);
}
.back-to-top[data-visible] { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { background: var(--primary-dark); }
.back-to-top:focus-visible { outline: 3px solid var(--secondary); outline-offset: 4px; }