/* CSS Variables */
:root {
  --primary: #0369a1;
  --secondary: #e0f2fe;
  --accent: #06b6d4;
  --text: #0c1a27;
  --bg: #f8faff;
}

/* Base Styles */
body {
  background: linear-gradient(135deg, #1e1b4b 0%, #311042 100%);
  color: #ffffff;
  min-height: 100vh;
}

section {
  padding: 32px 0;
}

/* Glassmorphism Card System */
.card {
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 16px;
}

/* Interactive CTA Button */
.btn {
  border-radius: 12px;
  background: #ffffff;
  color: #764ba2;
  font-weight: 700;
  min-height: 44px;
}

/* Screen Reader Only Utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Responsive Product Layout */
.product-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

@media (min-width: 768px) {
  .product-container {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }
}

/* Pure CSS Gallery */
.gallery-main {
  position: relative;
  width: 100%;
  padding-bottom: 100%; /* Perfect square aspect ratio representation */
  overflow: hidden;
  border-radius: 12px;
  background: rgba(0, 0, 0, 0.2);
}

.slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  z-index: 1;
  transition: opacity 0.4s ease-in-out;
}

.slide img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* Thumbnail Grid Layout */
.thumbnails {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-top: 16px;
}

.thumbnails label {
  cursor: pointer;
  border: 2px solid transparent;
  border-radius: 8px;
  overflow: hidden;
  transition: all 0.2s ease-in-out;
  background: rgba(255, 255, 255, 0.05);
}

.thumbnails label img {
  width: 100%;
  height: auto;
  aspect-ratio: 1;
  object-fit: cover;
  display: block;
}

.thumbnails label:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* Pure CSS Radio Selection Engine */
#img-1:checked ~ .gallery-main .slide-1 { opacity: 1; z-index: 10; }
#img-2:checked ~ .gallery-main .slide-2 { opacity: 1; z-index: 10; }
#img-3:checked ~ .gallery-main .slide-3 { opacity: 1; z-index: 10; }
#img-4:checked ~ .gallery-main .slide-4 { opacity: 1; z-index: 10; }

#img-1:checked ~ .thumbnails label[for="img-1"] { border-color: var(--accent); transform: scale(0.95); }
#img-2:checked ~ .thumbnails label[for="img-2"] { border-color: var(--accent); transform: scale(0.95); }
#img-3:checked ~ .thumbnails label[for="img-3"] { border-color: var(--accent); transform: scale(0.95); }
#img-4:checked ~ .thumbnails label[for="img-4"] { border-color: var(--accent); transform: scale(0.95); }

/* Typography Scale via clamp() */
h1 {
  font-size: clamp(20px, 4.5vw, 28px);
}

h2 {
  font-size: clamp(22px, 5vw, 32px);
}

p {
  font-size: clamp(14px, 3.5vw, 16px);
}