/* CLEAN-WHITE Design System */
:root {
  --primary: #1e3a5f;
  --secondary: #e8f0fe;
  --accent: #ff6b35;
  --text: #0f1c2e;
  --bg: #f8fafc;
}

body {
  background: #ffffff;
  color: #111111;
  font-family: 'Inter', sans-serif;
  font-size: clamp(14px, 4vw, 16px);
  line-height: 1.5;
  margin: 0;
  padding: 0;
}

section {
  padding: 64px 16px;
}

.card {
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  box-shadow: none;
}

.btn {
  border-radius: 6px;
  font-weight: 600;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

h1, h2 {
  font-weight: 700;
}

h1 {
  font-size: clamp(22px, 5vw, 36px);
}

h2 {
  font-size: clamp(18px, 4.5vw, 28px);
}

/* Gallery Core Rules */
.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-container {
  position: relative;
  width: 100%;
}

.gallery-main {
  position: relative;
  width: 100%;
  padding-bottom: 100%;
  overflow: hidden;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  background-color: #f9fafb;
}

.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;
}

/* Slide Selection Logic */
#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;
}

/* Thumbnails Styles */
.thumbnails {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-top: 12px;
}

.thumbnails label {
  cursor: pointer;
  border: 2px solid transparent;
  border-radius: 6px;
  overflow: hidden;
  aspect-ratio: 1 / 1;
  display: block;
}

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

/* Thumbnail Active State Logic */
#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(--primary);
}