body{font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;margin:0;padding:1rem;background:#f6f7fb;color:#111}
    h1{margin:.2rem 0 .4rem}
    section { padding: 2rem 1rem; max-width: 1200px; margin: auto;}
    #map{height:380px;border-radius:10px;margin:10px 0;background:#e9eef5}
    .row{display:flex;flex-wrap:wrap;gap:1rem}
    .col{flex:1 1 340px;background:#fff;border-radius:12px;box-shadow:0 8px 18px rgba(0,0,0,.08);padding:1rem}
    .btn{padding:.6rem 1rem;border:0;border-radius:8px;cursor:pointer;font-weight:600}
    .primary{background:#2563eb;color:#fff}
    .ghost{background:#e5e7eb}
    .ok{color:#16a34a}.warn{color:#f59e0b}.err{color:#ef4444}.muted{color:#6b7280}
    table{width:100%;border-collapse:collapse;font-size:.95rem}
    th,td{border:1px solid #e5e7eb;padding:.45rem .5rem}
    th{background:#f3f4f6;text-align:left}
    .controls label{display:block;font-size:.9rem;margin:.4rem 0 .2rem}
    .controls input{width:100%;padding:.45rem .5rem;border:1px solid #d1d5db;border-radius:8px}
    .small{font-size:.9rem}
    .topnav {
  background-color: #ffffff;
  border-bottom: 1px solid #ddd;
  position: sticky;
  top: 0;
  z-index: 999;
}
.topnav ul {
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0;
  padding: 0.75rem 0;
  list-style: none; /* Fixes bullet points */
  background-color: #ffffff;
}
.topnav ul li { margin: 0 1rem; }
.topnav a {
  text-decoration: none;
  color: #0a58ca;
  font-weight: 600;
  font-size: 1rem;
  padding: 0.5rem 1rem;
  border-radius: 5px;
  transition: background-color 0.3s, color 0.3s;
}
.topnav a:hover,
.topnav a.active {
  background-color: #0a58ca;
  color: #fff;
}

/* ===== HEADER WITH LOGO LEFT ===== */
header {
  background: linear-gradient(135deg, #002663, #004080);
  color: #f0f2f5;
  padding: 2.5rem 1rem;
  border-bottom: 5px solid #fdb913;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}
.header-layout {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  max-width: 1200px;
  margin: 0 auto;
  gap: 2rem;
  flex-wrap: wrap;
}
.logo-container {
  display: flex;
  align-items: flex-start; /* was 'left' (invalid) */
  background-color: transparent;
  border-right: 2px solid rgba(255, 255, 255, 0.2);
  padding: 0;
  margin: 0;
}
.dcu-logo-left {
  height: 100%;
  max-height: 160px;
  width: auto;
  object-fit: contain;
  margin: 0;
  padding: 0;
  align-self: stretch;
}
.header-content {
  text-align: center;
  flex: 1;
}
.header-content h1 {
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: #ffffff;
  text-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
}
.header-content .tagline,
.header-content .author {
  font-size: 1.1rem;
  color: #d8dce3;
  margin: 0.3rem 0;
}

/* ====== SENSOR SECTION ====== */
label {
  font-size: 1.1rem;
  font-weight: 600;
}
select {
  font-size: 1rem;
  padding: 0.5rem;
  margin-left: 0.5rem;
  border-radius: 6px;
  border: 1px solid #ccc;
}

/* ====== TABS ====== */
.tabs {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0;
}
.tablink {
  background-color: #eee;
  border: none;
  padding: 10px 20px;
  font-size: 1rem;
  cursor: pointer;
  font-weight: bold;
  border-radius: 5px;
  transition: 0.3s;
}
.tablink:hover { background-color: #cce0ff; }
.tablink.active {
  background-color: #0a58ca;
  color: white;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

/* ====== TAB GRID ====== */
.tab-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
  margin-top: 1rem;
}
.tabcontent { display: none; }
.tab-box {
  flex: 1 1 30%;
  min-width: 300px;
  /* allow content to size naturally; GPS tab needs more height */
  background: white;
  padding: 1rem;
  border-radius: 10px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  box-sizing: border-box;
  overflow: hidden;
  transition: transform 0.3s ease;
}
.tab-box:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 18px rgba(0,0,0,0.12);
}
.tab-box p {
  font-size: 1.2rem;
  font-weight: bold;
  margin-bottom: 0.75rem;
}

/* Let the GPS card expand and show a big map */
#gps.tab-box { max-height: none; }

/* ====== IFRAME ====== */
iframe {
  width: 100%;
  height: 325px;
  border: none;
  border-radius: 8px;
  overflow: hidden;
}

    /* ====== RESPONSIVE ====== */
@media (max-width: 768px) {
  .tab-box { flex: 1 1 100%; }
  .topnav ul { flex-direction: column; gap: 0.5rem; }
  .tablink { font-size: 0.95rem; padding: 8px 14px; }
  header h1 { font-size: 1.5rem; }
  iframe { height: 300px; }
  #map { height: 360px; }
}
@media (max-width: 600px) {
  .header-layout { flex-direction: column; align-items: center; }
  .dcu-logo-left { margin-bottom: 1rem; }
  iframe { height: 280px; }
  #map { height: 320px; }
}