/**
 * Premium Stylesheet for OA ROM Unloader Knee Brace Product Page
 * Core Tone Architecture: Minimalist Muted Rose / Soft Pink Premium Visual Delivery
 * Pure Custom CSS Architecture Engine
 */

/* ==========================================================================
   1. ROOT VARIABLES & GLOBAL DECLARATIONS
   ========================================================================== */
:root {
    /* Main Color Core Tokens - Strict Pink/Rose Alignment */
    --primary-rose-main: #db2777;
    --primary-rose-hover: #be185d;
    --primary-rose-light: #fce7f3;
    --primary-rose-ultra-light: #fff1f2;
    --primary-rose-deep: #9d174d;
    --primary-rose-trans: rgba(219, 39, 119, 0.15);
    
    /* Neutrals Architecture */
    --neutral-bg-body: #faf5f6;
    --neutral-card-bg: #ffffff;
    --text-main-dark: #111827;
    --text-muted-gray: #6b7280;
    --border-gray-soft: #f3f4f6;
    --border-rose-soft: #fbcfe8;

    /* Multi-layered Custom Shadow Architecture */
    --shadow-level-1: 0 2px 4px 0 rgba(219, 39, 119, 0.02);
    --shadow-level-2: 0 4px 6px -1px rgba(219, 39, 119, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-level-3: 0 10px 15px -3px rgba(219, 39, 119, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.02);
    --shadow-level-4: 0 20px 25px -5px rgba(219, 39, 119, 0.12), 0 10px 10px -5px rgba(219, 39, 119, 0.04);
    --shadow-premium-glow: 0 0 40px -5px rgba(219, 39, 119, 0.25);
    --shadow-inner-soft: inset 0 2px 4px 0 rgba(0, 0, 0, 0.04);

    /* Animation Core Transitions */
    --transition-smooth-core: all 0.4s cubic-bezier(0.25, 1, 0.5, 1);
    --transition-fast-bounce: all 0.25s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

/* Base Optimization Overrides */
html {
    scroll-behavior: smooth;
    box-sizing: border-box;
}

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--neutral-bg-body);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    color: var(--text-main-dark);
    overflow-x: hidden;
    position: relative;
    min-height: 100vh;
}

/* ==========================================================================
   2. DECORATIVE BACKGROUND ANIMATED ELEMENTS (BLOBS & SHAPES)
   ========================================================================== */
.decor-blob-1 {
    position: absolute;
    top: -5%;
    left: -10%;
    width: 60vw;
    height: 60vw;
    background: radial-gradient(circle, rgba(253,244,245,1) 0%, rgba(251,207,232,0.3) 100%);
    border-radius: 50%;
    filter: blur(80px);
    z-index: 0;
    pointer-events: none;
    animation: floating-blob-a 25s infinite alternate ease-in-out;
}

.decor-blob-2 {
    position: absolute;
    top: 40%;
    right: -15%;
    width: 50vw;
    height: 50vw;
    background: radial-gradient(circle, rgba(255,241,242,1) 0%, rgba(24bcfe,0.2) 100%);
    border-radius: 50%;
    filter: blur(100px);
    z-index: 0;
    pointer-events: none;
    animation: floating-blob-b 30s infinite alternate ease-in-out;
}

.decor-blob-3 {
    position: absolute;
    bottom: 5%;
    left: -5%;
    width: 45vw;
    height: 45vw;
    background: radial-gradient(circle, rgba(253,242,248,1) 0%, rgba(251,207,232,0.25) 100%);
    border-radius: 50%;
    filter: blur(90px);
    z-index: 0;
    pointer-events: none;
}

@keyframes floating-blob-a {
    0% { transform: translate(0, 0) scale(1); }
    100% { transform: translate(5vw, 8vh) scale(1.15); }
}

@keyframes floating-blob-b {
    0% { transform: translate(0, 0) scale(1.1); }
    100% { transform: translate(-4vw, -6vh) scale(0.9); }
}

/* ==========================================================================
   3. HEADER ARCHITECTURE SPECIFICATIONS
   ========================================================================== */
.main-header-engine {
    background-color: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-b: 1px solid rgba(251, 207, 232, 0.4);
    box-shadow: var(--shadow-level-2);
    transition: var(--transition-smooth-core);
}

.header-glass-wrapper {
    position: relative;
    overflow: hidden;
}

.header-decorative-line-top {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--primary-rose-main), transparent);
}

.brand-title-frame {
    display: inline-block;
    position: relative;
    padding: 2px 0;
}

.brand-text-accent {
    font-weight: 800;
    font-size: 1.35rem;
    letter-spacing: -0.03em;
    background: linear-gradient(135deg, var(--text-main-dark) 30%, var(--primary-rose-deep) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    transition: var(--transition-smooth-core);
}

.header-badge-accent {
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.25em;
    color: var(--primary-rose-main);
    margin-top: 4px;
    opacity: 0.85;
}

/* ==========================================================================
   4. PRODUCT HERO SECTION & MULTI-LAYER CARD ENGINE
   ========================================================================== */
.product-hero-card-container {
    perspective: 1000px;
    z-index: 10;
}

.product-card-inner-grid {
    background-color: var(--neutral-card-bg);
    border-radius: 2rem;
    border: 1px solid rgba(251, 207, 232, 0.5);
    box-shadow: var(--shadow-level-4), var(--shadow-level-1);
    transition: var(--transition-smooth-core);
}

.product-card-inner-grid:hover {
    box-shadow: var(--shadow-level-4), var(--shadow-premium-glow);
    transform: translateY(-2px);
}

.card-radial-glow {
    background: radial-gradient(circle at 10% 10%, rgba(253,242,248,0.4) 0%, transparent 60%);
}

/* ==========================================================================
   5. GALLERY MECHANICS (PURE CSS LOGIC - ABSOLUTELY NO JS)
   ========================================================================== */
.gallery-engine-root {
    position: relative;
    width: 100%;
}

.main-display-frame-wrapper {
    width: 100%;
}

.main-frame-gradient-accent {
    background: linear-gradient(135deg, var(--primary-rose-main), var(--border-rose-soft));
    transition: var(--transition-smooth-core);
}

.product-card-inner-grid:hover .main-frame-gradient-accent {
    opacity: 0.45;
}

.main-image-viewport {
    width: 100%;
    background-color: #fffdfd;
    box-shadow: var(--shadow-inner-soft);
}

.gallery-slide-pane {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    display: flex;
    items-center: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: scale(0.96);
    transition: opacity 0.45s ease-in-out, transform 0.45s cubic-bezier(0.25, 1, 0.5, 1), visibility 0.45s;
    padding: 1.5rem;
}

.product-fluid-image {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    filter: drop-shadow(0 10px 15px rgba(219, 39, 119, 0.08));
    transition: var(--transition-smooth-core);
}

.gallery-slide-pane:hover .product-fluid-image {
    transform: scale(1.03);
}

/* CSS Selection Interactivity Mapping via Input Radio Structural Check */
#gallery-trigger-1:checked ~ .main-display-frame-wrapper .pane-index-1 { opacity: 1; visibility: visible; transform: scale(1); z-index: 2; }
#gallery-trigger-2:checked ~ .main-display-frame-wrapper .pane-index-2 { opacity: 1; visibility: visible; transform: scale(1); z-index: 2; }
#gallery-trigger-3:checked ~ .main-display-frame-wrapper .pane-index-3 { opacity: 1; visibility: visible; transform: scale(1); z-index: 2; }
#gallery-trigger-4:checked ~ .main-display-frame-wrapper .pane-index-4 { opacity: 1; visibility: visible; transform: scale(1); z-index: 2; }

/* Thumbnail Active Highlighting Matrices */
.thumbnail-inner-box {
    width: 100%;
    height: 100%;
    border-color: rgba(229, 231, 235, 0.7);
    background-color: #ffffff;
    box-shadow: var(--shadow-level-1);
}

.thumb-fluid-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
    transition: var(--transition-smooth-core);
}

.thumbnail-item-wrapper:hover .thumbnail-inner-box {
    border-color: var(--border-rose-soft);
    transform: translateY(-2px);
    box-shadow: var(--shadow-level-2);
}

.thumbnail-item-wrapper:hover .thumb-fluid-image {
    transform: scale(1.05);
}

/* Radio Control Active Highlight Engine Map */
#gallery-trigger-1:checked ~ .thumbnails-dock #thumb-label-1 .thumbnail-inner-box { border-color: var(--primary-rose-main); border-width: 2px; box-shadow: var(--shadow-level-3); background-color: var(--primary-rose-ultra-light); transform: scale(0.98); }
#gallery-trigger-2:checked ~ .thumbnails-dock #thumb-label-2 .thumbnail-inner-box { border-color: var(--primary-rose-main); border-width: 2px; box-shadow: var(--shadow-level-3); background-color: var(--primary-rose-ultra-light); transform: scale(0.98); }
#gallery-trigger-3:checked ~ .thumbnails-dock #thumb-label-3 .thumbnail-inner-box { border-color: var(--primary-rose-main); border-width: 2px; box-shadow: var(--shadow-level-3); background-color: var(--primary-rose-ultra-light); transform: scale(0.98); }
#gallery-trigger-4:checked ~ .thumbnails-dock #thumb-label-4 .thumbnail-inner-box { border-color: var(--primary-rose-main); border-width: 2px; box-shadow: var(--shadow-level-3); background-color: var(--primary-rose-ultra-light); transform: scale(0.98); }

/* ==========================================================================
   6. TYPOGRAPHY AND CONTENT DESCRIPTION BLOCK DESIGNS
   ========================================================================== */
.h1-heading-wrapper {
    position: relative;
}

.main-product-title {
    color: var(--text-main-dark);
    font-weight: 800;
    line-height: 1.15;
}

.h1-decorative-bar {
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-rose-main), transparent);
    border-radius: 2px;
}

.keyword-integration-box {
    background-color: rgba(255, 241, 242, 0.6);
    backdrop-filter: blur(5px);
}

.keyword-text {
    font-weight: 500;
    color: #4c0519; /* Deep maroon/pink context color */
}

/* Specifications Custom List Formatting Layouts */
.specs-bullet-dot {
    width: 8px;
    height: 8px;
    background-color: var(--primary-rose-main);
    border-radius: 50%;
    display: inline-block;
}

.spec-list-item-card {
    transition: var(--transition-smooth-core);
}

.spec-list-item-card:hover {
    transform: translateX(4px);
    border-color: rgba(251, 207, 232, 0.6);
    background-color: #fffbfc;
    box-shadow: var(--shadow-level-2);
}

.spec-icon-badge {
    box-shadow: var(--shadow-inner-soft);
    border: 1px solid rgba(251, 207, 232, 0.3);
}

/* ==========================================================================
   7. HIGH-CONVERTING CTA BUTTON COMPONENT DESIGN WITH SHINE ANIMATION
   ========================================================================== */
.main-cta-section-wrapper {
    z-index: 20;
}

.cta-inner-block-decoration {
    background-color: #ffffff;
    border: 1px solid rgba(251, 207, 232, 0.6);
    box-shadow: var(--shadow-level-3), 0 30px 60px -15px rgba(219, 39, 119, 0.1);
}

.cta-radial-bg {
    background: radial-gradient(circle at center, #ffffff 0%, #fff1f2 100%);
}

.ultimate-cta-button-link {
    background: linear-gradient(135deg, var(--primary-rose-main) 0%, var(--primary-rose-deep) 100%);
    box-shadow: 0 10px 25px -5px rgba(219, 39, 119, 0.45), 0 8px 10px -6px rgba(219, 39, 119, 0.3), inset 0 -3px 0 0 rgba(0,0,0,0.2);
    overflow: hidden;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

/* Pure CSS Glowing/Shine Animation Overlay Structure */
.btn-shine-layer {
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.35), transparent);
    transform: skewX(-25deg);
    transition: none;
}

/* CTA Interactivity Micro-responses */
.ultimate-cta-button-link:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: 0 20px 35px -5px rgba(219, 39, 119, 0.55), 0 12px 16px -6px rgba(219, 39, 119, 0.4), inset 0 -3px 0 0 rgba(0,0,0,0.1);
    background: linear-gradient(135deg, #ec4899 0%, var(--primary-rose-hover) 100%);
}

.ultimate-cta-button-link:hover .btn-shine-layer {
    left: 150%;
    transition: left 0.85s cubic-bezier(0.4, 0, 0.2, 1);
}

.ultimate-cta-button-link:active {
    transform: translateY(-1px) scale(0.99);
    box-shadow: 0 8px 15px -5px rgba(219, 39, 119, 0.4), inset 0 2px 4px 0 rgba(0,0,0,0.2);
}

/* ==========================================================================
   8. REVIEWS COMPONENT (AMAZON LAYOUT RE-ENGINEERED WITH PINK PALETTE)
   ========================================================================== */
.reviews-section-root {
    position: relative;
    z-index: 10;
}

.review-row-container {
    transition: var(--transition-smooth-core);
    background-color: var(--neutral-card-bg);
}

.review-row-container:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-level-3), 0 4px 20px rgba(219, 39, 119, 0.04);
    border-color: var(--border-rose-soft);
}

.avatar-frame-wrapper {
    position: relative;
    width: 52px;
    height: 52px;
    display: flex;
    align-items: center;
    justify-content: center;
}

@keyframes spin-slow {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.animate-spin-slow {
    animation: spin-slow 12s linear infinite;
}

.user-avatar-image {
    object-fit: cover;
}

.stars-indicator-strip {
    color: #f59e0b; /* Authentic rich star tone */
    letter-spacing: 0.1em;
}

.review-title-text {
    color: var(--text-main-dark);
}

.verified-purchase-badge-container {
    letter-spacing: -0.01em;
}

.attached-photo-frame {
    transition: var(--transition-fast-bounce);
}

/* ==========================================================================
   9. FOOTER SYSTEMS DESIGN
   ========================================================================== */
.main-footer-engine {
    background-color: #ffffff;
    border-top: 1px solid rgba(251, 207, 232, 0.5);
    box-shadow: 0 -10px 30px -5px rgba(219, 39, 119, 0.03);
}

.footer-brand-title {
    font-size: 1rem;
    letter-spacing: 0.05em;
}

.footer-anchor-tag {
    color: var(--text-muted-gray);
    position: relative;
    display: inline-block;
    transition: var(--transition-smooth-core);
}

.footer-anchor-tag::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 1px;
    background-color: var(--primary-rose-main);
    transition: var(--transition-smooth-core);
    transform: translateX(-50%);
}

.footer-anchor-tag:hover {
    color: var(--primary-rose-main);
}

.footer-anchor-tag:hover::after {
    width: 80%;
}

/* ==========================================================================
   10. MOBILE-FIRST RESPONSIVE MEDIA QUERIES & VIEWPORT MATRICES
   ========================================================================== */

/* Very Small Viewports Optimization (320px up to 375px) */
@media (max-width: 375px) {
    .main-product-title {
        font-size: 1.75rem !important;
    }
    
    .ultimate-cta-button-link {
        padding: 1.25rem 2rem !important;
        font-size: 0.95rem !important;
    }
    
    .p-4 {
        padding: 0.85rem !important;
    }
}

/* Tablet Layout Modifications (768px onwards) */
@media (min-width: 768px) {
    .review-user-sidebar {
        flex-direction: column !important;
        align-items: flex-start !important;
        text-align: left;
    }
    
    .review-row-container {
        flex-direction: row !important;
    }
}

/* Desktop Fine-tuning Matrix Blocks (1024px and beyond) */
@media (min-width: 1024px) {
    .product-card-inner-grid {
        align-items: stretch;
    }
    
    .gallery-engine-root {
        position: sticky;
        top: 100px; /* Locks the gallery layout viewport cleanly on scroll */
    }
}
.main-image-viewport {
    width: 100%;
    aspect-ratio: 1 / 1;
    min-height: 320px;
}

@media (max-width: 480px) {
    .main-image-viewport {
        min-height: 280px;
    }
}