body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f7f7f7;
  color: #333;
}

header {
  position: relative;           /* needed for bubble layers */
  background: #004aad;          /* your blue */
  color: white;
  padding: 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  overflow: hidden;             /* hide animated bubble overflow */
}

/* keep header content above the bubbles */
header * {
  position: relative;
  z-index: 2;
}

/* -------------------------
   Desktop navigation
   ------------------------- */
.nav-links {
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  color: white;
  text-decoration: none;
  font-size: 1.2rem;
  font-weight: 600;
}

.nav-links a:hover {
  text-decoration: underline;
}

/* -------------------------
   Hamburger button
   ------------------------- */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 30px;
  height: 24px;
  background: none;
  border: none;
  cursor: pointer;
  z-index: 1000;
}

.hamburger span {
  display: block;
  height: 3px;
  width: 100%;
  background: white;
  border-radius: 3px;
}

/* -------------------------
   Responsive nav (mobile)
   ------------------------- */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    flex-direction: column;
    background: #004aad; /* match banner */
    position: absolute;
    top: 70px;
    right: 10px;
    padding: 1rem;
    border-radius: 8px;
  }

  .nav-links.active {
    display: flex;
  }

  .hamburger {
    display: flex;
  }
}

main {
  padding: 2rem;
  text-align: center;
}

.button {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  background: #004aad;
  color: white;
  border-radius: 5px;
  text-decoration: none;
  margin-top: 1rem;
}

.card {
  background: white;
  border-radius: 8px;
  padding: 1.5rem;
  margin: 1rem auto;
  max-width: 300px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.card .price {
  font-size: 1.5rem;
  font-weight: bold;
}

.card.highlight {
  border: 2px solid #004aad;
}

.logo {
  max-height: 180px;  /* Change number to resize logo */
  width: auto;        /* Keeps proportions correct */
  display: block;
  margin: 0 auto;     /* Centers logo horizontally */
}

/* -------------------------
   Animated bubble effect
   ------------------------- */

header::before,
header::after {
  content: "";
  position: absolute;
  left: -50%;
  top: -50%;
  width: 200%;
  height: 200%;
  pointer-events: none; /* allow clicks on nav */
  z-index: 1;
  background-repeat: repeat;
}

/* Foreground bubbles (smaller, faster) */
header::before {
  background-image:
    radial-gradient(circle at 10% 20%, rgba(255,255,255,0.85) 0 6px, transparent 8px),
    radial-gradient(circle at 40% 70%, rgba(255,255,255,0.65) 0 4px, transparent 6px),
    radial-gradient(circle at 80% 30%, rgba(255,255,255,0.6) 0 8px, transparent 10px);
  background-size: 140px 140px;
  opacity: 0.55;
  animation: bubblesFloat1 12s linear infinite;
}

/* Background bubbles (bigger, slower) */
header::after {
  background-image:
    radial-gradient(circle at 20% 40%, rgba(255,255,255,0.45) 0 12px, transparent 14px),
    radial-gradient(circle at 70% 80%, rgba(255,255,255,0.35) 0 8px, transparent 10px);
  background-size: 260px 260px;
  opacity: 0.35;
  animation: bubblesFloat2 18s linear infinite;
}

@keyframes bubblesFloat1 {
  from { transform: translateY(0); }
  to   { transform: translateY(-50%); }
}

@keyframes bubblesFloat2 {
  from { transform: translateY(0); }
  to   { transform: translateY(-80%); }
}

/* Respect reduced motion preferences */
@media (prefers-reduced-motion: reduce) {
  header::before,
  header::after {
    animation: none;
    opacity: 0.25;
  }
}

/* Disable bubbles on very small screens */
@media (max-width: 520px) {
  header::before,
  header::after {
    display: none;
  }
}