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

:root {
  --primary: #1a56db;
  --primary-dark: #1642a8;
  --text: #1f2937;
  --text-light: #6b7280;
  --bg: #ffffff;
  --bg-soft: #f3f6fc;
  --border: #e5e7eb;
  --radius: 14px;
}

html { scroll-behavior: smooth; background: var(--bg); }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  margin: 0;
  padding: 0;
}

a { color: inherit; text-decoration: none; }

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--primary);
}

.logo-text {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--text);
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav-link {
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 15px;
  color: var(--text);
  transition: background 0.2s, color 0.2s;
}

.nav-link:hover { background: var(--bg-soft); color: var(--primary); }
.nav-link.active { color: var(--primary); font-weight: 600; }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  cursor: pointer;
  padding: 6px;
}

/* Hero */
.hero {
  background: linear-gradient(135deg, #f3f6fc 0%, #e8effb 100%);
  padding: 88px 0 72px;
  text-align: center;
}

.hero h1 {
  font-size: 52px;
  font-weight: 800;
  letter-spacing: 4px;
  color: var(--text);
  margin-bottom: 14px;
}

.hero-sub {
  font-size: 20px;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 16px;
  letter-spacing: 2px;
}

.hero-desc {
  max-width: 680px;
  margin: 0 auto 40px;
  font-size: 16px;
  color: var(--text-light);
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 32px;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background 0.2s, transform 0.15s, box-shadow 0.2s;
}

.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 6px 18px rgba(26, 86, 219, 0.28);
}

.btn-primary:hover { background: var(--primary-dark); }

.btn-outline {
  background: transparent;
  color: var(--primary);
  border-color: var(--primary);
}

.btn-outline:hover { background: rgba(26, 86, 219, 0.08); }

/* Features */
.features { padding: 56px 0; }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.feature-item {
  text-align: center;
  padding: 24px 16px;
  border-radius: var(--radius);
  background: var(--bg-soft);
}

.feature-item svg { color: var(--primary); margin-bottom: 10px; }

.feature-item h3 { font-size: 16px; margin-bottom: 6px; }

.feature-item p { font-size: 13px; color: var(--text-light); }

/* Sections */
.section-title {
  text-align: center;
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 10px;
}

.section-sub {
  text-align: center;
  font-size: 15px;
  color: var(--text-light);
  margin-bottom: 40px;
}

.sub-title {
  text-align: center;
  font-size: 21px;
  font-weight: 700;
  margin: 48px 0 24px;
}

/* Devices */
.devices { padding: 72px 0; background: var(--bg-soft); }

.device-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.device-card {
  position: relative;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: box-shadow 0.25s, transform 0.25s;
}

.device-card:hover {
  box-shadow: 0 10px 30px rgba(17, 24, 39, 0.1);
  transform: translateY(-4px);
}

.device-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  color: var(--primary);
  background: rgba(26, 86, 219, 0.1);
  border-radius: 999px;
  padding: 3px 12px;
  margin-bottom: 12px;
}

.device-card h3 { font-size: 19px; margin-bottom: 4px; }

.device-chip { font-size: 13px; color: var(--primary); font-weight: 600; margin-bottom: 14px; }

.device-spec {
  list-style: none;
  margin-bottom: 14px;
}

.device-spec li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  color: var(--text);
  margin-bottom: 6px;
}

.device-spec li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 8px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary);
  opacity: 0.7;
}

.device-use {
  font-size: 13.5px;
  color: var(--text-light);
  margin-bottom: 16px;
}

.service-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
}

.service-link:hover { color: var(--primary-dark); }

/* Scenes */
.scenes { padding: 72px 0; }

.scene-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.scene-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 22px;
  text-align: center;
  transition: box-shadow 0.25s, transform 0.25s;
}

.scene-item:hover {
  box-shadow: 0 10px 30px rgba(17, 24, 39, 0.08);
  transform: translateY(-4px);
}

.scene-item svg { color: var(--primary); margin-bottom: 10px; }

.scene-item h3 { font-size: 16px; margin-bottom: 6px; }

.scene-item p { font-size: 13.5px; color: var(--text-light); }

/* Services */
.services { padding: 72px 0; background: var(--bg-soft); }

.service-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: 820px;
  margin: 0 auto;
}

.service-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  text-align: center;
  transition: box-shadow 0.25s, transform 0.25s;
  background: var(--bg);
}

.service-card:hover {
  box-shadow: 0 10px 30px rgba(17, 24, 39, 0.08);
  transform: translateY(-4px);
}

.service-icon {
  color: var(--primary);
  margin-bottom: 14px;
}

.service-card h3 {
  font-size: 19px;
  margin-bottom: 8px;
}

.service-card p {
  font-size: 14px;
  color: var(--text-light);
  margin-bottom: 18px;
}

/* Footer */
.site-footer {
  margin: auto 0 0;
  border-top: 1px solid var(--border);
  background: var(--bg);
  padding: 20px 0 0;
  text-align: center;
  font-size: 13px;
  color: var(--text-light);
}

/* Modal */
.modal-mask {
  position: fixed;
  inset: 0;
  z-index: 100;
  background: rgba(15, 23, 42, 0.55);
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal-mask.show { display: flex; }

.modal {
  position: relative;
  background: #fff;
  border-radius: 16px;
  padding: 32px;
  text-align: center;
  max-width: 320px;
  width: 100%;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.25);
}

.modal-close {
  position: absolute;
  top: 10px;
  right: 10px;
  background: none;
  border: none;
  color: var(--text-light);
  cursor: pointer;
  padding: 6px;
  border-radius: 8px;
}

.modal-close:hover { background: var(--bg-soft); color: var(--text); }

.modal-qr {
  width: 200px;
  height: 200px;
  border-radius: 10px;
  border: 1px solid var(--border);
  display: block;
  margin: 0 auto 16px;
}

.modal-tip {
  font-size: 14px;
  color: var(--text-light);
}

/* Mobile (<= 1024px) */
@media (max-width: 1024px) {
  .nav-toggle { display: block; }

  .main-nav {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: #fff;
    border-bottom: 1px solid var(--border);
    padding: 12px 20px 16px;
    display: none;
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.06);
  }

  .main-nav.open { display: flex; }

  .nav-link { padding: 12px 12px; font-size: 16px; }

  .hero { padding: 64px 0 56px; }
  .hero h1 { font-size: 36px; letter-spacing: 2px; }
  .hero-sub { font-size: 16px; letter-spacing: 1px; }
  .hero-desc { font-size: 14.5px; }

  .feature-grid { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .device-grid { grid-template-columns: 1fr; }
  .scene-grid { grid-template-columns: 1fr; }
  .service-grid { grid-template-columns: 1fr; }

  .section-title { font-size: 24px; }
  .devices { padding: 56px 0; }
  .scenes { padding: 56px 0; }
  .services { padding: 56px 0; }
}

/* Small mobile (<= 480px) */
@media (max-width: 480px) {
  .feature-grid { grid-template-columns: 1fr; }
  .hero-actions .btn { width: 100%; justify-content: center; }
}

/* Inner pages */
.page-main { padding: 48px 0 64px; }

.page-head { text-align: center; margin-bottom: 40px; }

.page-head h1 { font-size: 32px; font-weight: 800; }

.page-head p {
  color: var(--text-light);
  margin-top: 10px;
  font-size: 15px;
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

.page-body .devices { background: transparent; padding: 0; }

.more-link {
  color: var(--primary);
  font-weight: 600;
  font-size: 14px;
  white-space: nowrap;
}

.more-link:hover { color: var(--primary-dark); }

.scene-tip {
  font-size: 13px;
  color: var(--primary);
  font-weight: 600;
  margin-top: 12px;
}

.scene-cta { text-align: center; margin-top: 48px; }

.scene-cta p { margin-bottom: 16px; color: var(--text-light); }

/* Footer */
.footer-inner { text-align: center; padding: 22px 0 0; }

.footer-links { margin-bottom: 12px; font-size: 14px; }

.footer-links a { color: var(--text-light); transition: color 0.2s; }

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

.footer-links .sep { margin: 0; color: var(--border); }

.footer-copy { font-size: 13px; color: var(--text-light); margin-bottom: 4px; }

.footer-icp a { font-size: 13px; color: var(--text-light); }

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

/* Legal pages */
.privacy-wrap { max-width: 900px; margin: 0 auto; }

.privacy-head { text-align: center; margin-bottom: 32px; }

.privacy-head h1 { font-size: 28px; font-weight: 800; }

.privacy-head .meta {
  color: var(--text-light);
  font-size: 13px;
  margin-top: 8px;
  white-space: pre-line;
  line-height: 1.8;
}

.privacy-card h2 { font-size: 19px; margin: 30px 0 12px; }

.privacy-card h3 { font-size: 16px; margin: 22px 0 8px; }

.privacy-card p { font-size: 14.5px; margin-bottom: 10px; line-height: 1.8; }

.privacy-card ol { padding-left: 22px; margin-bottom: 10px; }

.privacy-card li { font-size: 14.5px; margin-bottom: 6px; line-height: 1.8; }

@media (max-width: 1024px) {
  .page-main { padding: 32px 0 48px; }
  .page-head h1 { font-size: 26px; }
  .privacy-head h1 { font-size: 23px; }
  .footer-links { font-size: 12.5px; }
}