/* CSS Variables & Theme Configuration */
:root {
    --primary: #52525b;
    --secondary: #fafafa;
    --accent: #0ea5e9;
    --text: #18181b;
    --bg: #ffffff;
}

/* Base resets & styles */
body {
    background: var(--bg);
    color: var(--text);
}

section {
    padding: 64px 16px;
}

.card {
    border-radius: 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
}

h1 {
    font-weight: 800;
    line-height: 1.1;
    font-size: clamp(22px, 5vw, 36px);
}

.btn {
    border-radius: 16px;
    font-weight: 700;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
    min-height: 44px;
}

/* Mobile-first clamping */
p, span, label, a {
    font-size: clamp(14px, 4vw, 16px);
}

/* Gallery Engine (Pure CSS) */
.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-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;
}

/* Toggle slides based on checked radio state */
#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;
}

/* Active Thumbnail Styling */
#img-1:checked ~ .thumbnails label[for="img-1"] {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(14, 165, 233, 0.2);
}

#img-2:checked ~ .thumbnails label[for="img-2"] {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(14, 165, 233, 0.2);
}

#img-3:checked ~ .thumbnails label[for="img-3"] {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(14, 165, 233, 0.2);
}

#img-4:checked ~ .thumbnails label[for="img-4"] {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(14, 165, 233, 0.2);
}