/* CSS Custom Variables & Core Styles */
:root {
  --primary: #52525b;
  --secondary: #fafafa;
  --accent: #0ea5e9;
  --text: #f5f5f5;
  --bg: #0f0f0f;
}

body {
  background: var(--bg);
  color: var(--text);
  font-size: clamp(14px, 4vw, 16px);
}

section {
  padding: 40px 16px;
}

@media (min-width: 768px) {
  section {
    padding: 64px 16px;
  }
}

.card {
  background: #1a1a1a;
  border: 1px solid #333;
  border-radius: 12px;
}

.btn {
  border-radius: 8px;
  background: var(--accent);
  color: #ffffff;
  font-weight: 700;
  min-height: 44px;
}

h1 {
  font-weight: 800;
  font-size: clamp(20px, 4.5vw, 28px);
}

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

/* Accessibility & 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;
}

/* Gallery Functionality */
.gallery-main {
  position: relative;
  width: 100%;
  padding-bottom: 100%; /* Strict height constraint */
  overflow: hidden;
}

.slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  z-index: 1;
  transition: opacity 0.3s ease-in-out;
}

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

/* Checked States for Gallery */
#img-1:checked ~ .gallery-main .slide-1,
#img-2:checked ~ .gallery-main .slide-2,
#img-3:checked ~ .gallery-main .slide-3,
#img-4:checked ~ .gallery-main .slide-4 {
  opacity: 1;
  z-index: 10;
}

/* Checked States for Thumbnails */
#img-1:checked ~ .thumbnails label[for="img-1"],
#img-2:checked ~ .thumbnails label[for="img-2"],
#img-3:checked ~ .thumbnails label[for="img-3"],
#img-4:checked ~ .thumbnails label[for="img-4"] {
  border-color: var(--accent);
  opacity: 1;
}