/* CSS-Only Design System & Gallery */

:root {
    --primary: #4f46e5;
    --accent: #22d3ee;
    --text-light: #ffffff;
}

/* Mobile-First Base Styles */
body {
    background: linear-gradient(135deg, #312e81 0%, #4c1d95 100%);
    color: var(--text-light);
    min-height: 100vh;
    font-family: 'Inter', sans-serif;
    overflow-x: hidden;
}

section {
    padding: 32px 16px;
}

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

/* Typography clamp settings */
h1 {
    font-size: clamp(20px, 4vw, 28px);
}

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

p {
    font-size: clamp(14px, 4vw, 16px);
}

/* Glass-Frost Cards */
.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;
}

/* CTA Button Styling */
.btn {
    border-radius: 12px;
    background: #ffffff;
    color: #312e81;
    font-weight: 700;
    min-height: 48px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3);
    background: #f8fafc;
}

/* Screen Reader Only class (Safe CSS-Gallery Toggle) */
.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 Layout */
.gallery-main {
    position: relative;
    width: 100%;
    padding-bottom: 100%; /* Perfect 1:1 Aspect Ratio */
    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;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

/* Active Slide Bindings */
#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 */
.thumbnails {
    display: flex;
    gap: 12px;
    margin-top: 16px;
    justify-content: center;
}

.thumbnails label {
    width: 64px;
    height: 64px;
    border: 2px solid transparent;
    border-radius: 8px;
    overflow: hidden;
    cursor: pointer;
    transition: all 0.2s ease-in-out;
    background: rgba(255, 255, 255, 0.1);
}

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

/* Active Thumbnail Bindings */
#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);
    box-shadow: 0 0 12px rgba(34, 211, 238, 0.6);
    transform: scale(1.05);
}