body {
  margin: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: #f8fafc;
  color: #1e293b;
}
.hdr-area {
  background: linear-gradient(135deg, #93c5fd, #60a5fa);
  color: white;
  text-align: center;
  padding: 3rem 1.5rem;
}
.site-hdr {
  font-size: 2.5rem;
  margin-bottom: 0.3rem;
}
.site-tag {
  font-size: 1.1rem;
}
.cta-sub {
  display: inline-block;
  margin-top: 1.5rem;
  background: #1e3a8a;
  color: white;
  padding: 0.8rem 1.4rem;
  border-radius: 6px;
  text-decoration: none;
}
.cta-sub:hover {
  background: #3b82f6;
}
.nav-header {
  background: #e0f2fe;
  padding: 1rem;
  text-align: center;
}
.tab-link {
  margin: 0 1rem;
  color: #1d4ed8;
  font-weight: bold;
  text-decoration: none;
}
.tab-link.selected {
  text-decoration: underline;
}
.container-core {
  max-width: 850px;
  margin: 2rem auto;
  padding: 1rem;
}
.panel-tab {
  display: none;
}
.panel-tab.visible {
  display: block;
}
.footer-zone {
  background: #e0f2fe;
  color: #334155;
  text-align: center;
  padding: 2rem 1rem;
}
a[href^="mailto:"] {
  color: #1e3a8a;
  text-decoration: underline;
}