/* ==========================================================================
   FEATOL Carpal Tunnel - Advanced Tailored CSS Framework
   Target: E-Commerce Landing Page Optimization
   Strict Palette Theme: Red-Centric (#DC2626, #B91C1C, #991B1B) & Muted Neutrals
   ========================================================================== */

/* 1. Global Custom Custom Properties & CSS Variables */
:root {
    --primary-red-base: #dc2626;
    --primary-red-hover: #b91c1c;
    --primary-red-dark: #991b1b;
    --primary-red-light: #fee2e2;
    --primary-red-glow: rgba(220, 38, 38, 0.15);
    --primary-red-glow-heavy: rgba(220, 38, 38, 0.4);
    
    --neutral-bg-body: #fafbfc;
    --neutral-card-white: #ffffff;
    --neutral-text-main: #1f2937;
    --neutral-text-muted: #6b7280;
    --neutral-text-light: #9ca3af;
    
    --gallery-panel-bg: #fdfefe;
    --border-color-soft: #f3f4f6;
    --border-color-mid: #e5e7eb;
    
    --shadow-level-1: 0 1px 3px rgba(0,0,0,0.05), 0 1px 2px rgba(0,0,0,0.03);
    --shadow-level-2: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-level-3: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.02);
    --shadow-level-4: 0 20px 25px -5px rgba(220, 38, 38, 0.04), 0 10px 10px -5px rgba(0, 0, 0, 0.02);
    --shadow-premium-card: 0 25px 50px -12px rgba(0, 0, 0, 0.06), 0 0 40px rgba(220, 38, 38, 0.015);
    --shadow-inner-soft: inset 0 2px 4px 0 rgba(0, 0, 0, 0.04);
    
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 2. Document Defaults Overrides & Optimizations */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--neutral-bg-body);
    color: var(--neutral-text-main);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    letter-spacing: -0.011em;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Extra micro font utilities */
.text-xxs {
    font-size: 0.6875rem;
}
.text-xxxs {
    font-size: 0.6rem;
}
.backdrop-blur-xs {
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

/* 3. Base Custom Background Decorative Geometry */
.absolute-decor-container {
    height: 1200px;
}

.decor-shape {
    position: absolute;
    border-radius: var(--radius-full);
    filter: blur(140px);
    opacity: 0.45;
    z-index: 0;
    animation: floatingBackgroundGlow 20s infinite alternate ease-in-out;
}

.bg-glow-circle-1 {
    width: 450px;
    height: 450px;
    top: -100px;
    left: -150px;
    background: radial-gradient(circle, var(--primary-red-base) 0%, transparent 70%);
}

.bg-glow-circle-2 {
    width: 500px;
    height: 500px;
    top: 300px;
    right: -200px;
    background: radial-gradient(circle, rgba(220,38,38,0.7) 0%, transparent 70%);
    animation-delay: -5s;
}

.bg-glow-circle-3 {
    width: 350px;
    height: 350px;
    top: 850px;
    left: 20%;
    background: radial-gradient(circle, rgba(153,27,27,0.4) 0%, transparent 70%);
    animation-delay: -10s;
}

.bg-mesh-pattern {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    opacity: 0.02;
    background-image: radial-gradient(var(--neutral-text-main) 1px, transparent 1px);
    background-size: 24px 24px;
    filter: none;
}

/* Keyframe Animations */
@keyframes floatingBackgroundGlow {
    0% { transform: translateY(0) scale(1); }
    100% { transform: translateY(30px) scale(1.08); }
}

@keyframes softButtonPulse {
    0% { box-shadow: 0 0 0 0 rgba(220, 38, 38, 0.4); }
    70% { box-shadow: 0 0 0 16px rgba(220, 38, 38, 0); }
    100% { box-shadow: 0 0 0 0 rgba(220, 38, 38, 0); }
}

@keyframes btnShimmer {
    0% { left: -150%; }
    50% { left: 150%; }
    100% { left: 150%; }
}

/* 4. Custom Header Architecture Component */
.custom-header {
    height: 72px;
    background-color: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-b: 1px solid rgba(229, 231, 235, 0.6);
    box-shadow: var(--shadow-level-1);
}

.header-glass-backdrop {
    position: absolute;
    inset: 0;
    z-index: -1;
}

.header-accent-line {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--primary-red-base), transparent);
}

.header-brand-title {
    font-size: 1.35rem;
    font-weight: 800;
    letter-spacing: 0.15em;
}

/* 5. Main Hero Product Card Component Styling */
.main-product-card {
    box-shadow: var(--shadow-premium-card);
    transition: transform var(--transition-normal);
}

.bg-gallery-panel {
    background-color: var(--gallery-panel-bg);
}

.card-glow-overlay {
    position: absolute;
    inset: 0;
    pointer-events: none;
    border-radius: var(--radius-xl);
    box-shadow: inset 0 0 40px rgba(255, 255, 255, 0.6);
    z-index: 5;
}

.card-corner-accent {
    position: absolute;
    width: 24px;
    height: 24px;
    border-color: rgba(220, 38, 38, 0.15);
    border-style: solid;
    pointer-events: none;
    z-index: 6;
}
.card-corner-accent.top-l { top: 16px; left: 16px; border-width: 2px 0 0 2px; }
.card-corner-accent.bot-r { bottom: 16px; right: 16px; border-width: 0 2px 2px 0; }

/* 6. Pure CSS Non-JavaScript Gallery Engine */
.master-image-viewport {
    box-shadow: var(--shadow-inner-soft);
}

.gallery-slide {
    opacity: 0;
    pointer-events: none;
    transform: scale(0.97);
}

/* Cross-coupling Gallery Selectors Logic */
.gallery-trigger-1:checked ~ .master-image-viewport .slide-index-1,
.gallery-trigger-2:checked ~ .master-image-viewport .slide-index-2,
.gallery-trigger-3:checked ~ .master-image-viewport .slide-index-3,
.gallery-trigger-4:checked ~ .master-image-viewport .slide-index-4 {
    opacity: 1;
    pointer-events: auto;
    transform: scale(1);
    z-index: 10;
}

/* Active Thumbnails Highlighters Styles */
.gallery-trigger-1:checked ~ .thumbnails-grid-container #thumb-lbl-1,
.gallery-trigger-2:checked ~ .thumbnails-grid-container #thumb-lbl-2,
.gallery-trigger-3:checked ~ .thumbnails-grid-container #thumb-lbl-3,
.gallery-trigger-4:checked ~ .thumbnails-grid-container #thumb-lbl-4 {
    border-color: var(--primary-red-base);
    box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.15);
    transform: translateY(-2px);
}

.gallery-trigger-1:checked ~ .thumbnails-grid-container #thumb-lbl-1 .thumb-indicator-dot,
.gallery-trigger-2:checked ~ .thumbnails-grid-container #thumb-lbl-2 .thumb-indicator-dot,
.gallery-trigger-3:checked ~ .thumbnails-grid-container #thumb-lbl-3 .thumb-indicator-dot,
.gallery-trigger-4:checked ~ .thumbnails-grid-container #thumb-lbl-4 .thumb-indicator-dot {
    opacity: 1;
}

/* Thumbnail Item Wrappers */
.thumbnail-item-wrapper {
    position: relative;
    box-shadow: var(--shadow-level-1);
}
.thumbnail-item-wrapper:hover {
    border-color: rgba(220, 38, 38, 0.5);
    transform: translateY(-1px);
}

.thumb-indicator-dot {
    position: absolute;
    bottom: 4px;
    right: 4px;
    width: 6px;
    height: 6px;
    background-color: var(--primary-red-base);
    border-radius: var(--radius-full);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

/* Pure CSS Gallery Navigation Overlays Engine */
.nav-arrow-group {
    display: none;
    width: 100%;
    justify-content: space-between;
    pointer-events: none;
}

.arrow-btn {
    width: 36px;
    height: 36px;
    background-color: rgba(255, 255, 255, 0.9);
    border: 1px solid var(--border-color-mid);
    border-radius: var(--radius-full);
    position: relative;
    transition: all var(--transition-fast);
}
.arrow-btn:hover {
    background-color: #ffffff;
    border-color: var(--primary-red-base);
    transform: scale(1.05);
}

.arrow-btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 8px;
    height: 8px;
    border-bottom: 2px solid var(--neutral-text-main);
    border-left: 2px solid var(--neutral-text-main);
}
.left-arrow::before { transform: translate(-30%, -50%) rotate(45deg); }
.right-arrow::before { transform: translate(-70%, -50%) rotate(-135deg); }

/* Controlling which navigation arrows group appears dynamically */
.gallery-trigger-1:checked ~ .master-image-viewport .nav-group-from-1,
.gallery-trigger-2:checked ~ .master-image-viewport .nav-group-from-2,
.gallery-trigger-3:checked ~ .master-image-viewport .nav-group-from-3,
.gallery-trigger-4:checked ~ .master-image-viewport .nav-group-from-4 {
    display: flex;
}

/* 7. Right Typography Column Layout Styles */
.title-underline-element {
    display: block;
    width: 64px;
    height: 4px;
    background-color: var(--primary-red-base);
    border-radius: var(--radius-full);
    margin-top: 8px;
}

.mandatory-keyword-box {
    box-shadow: inset 0 0 12px rgba(220, 38, 38, 0.01);
}

.payload-card {
    transition: all var(--transition-normal);
}

/* 8. Advanced Specialized Conversion CTA Section */
.cta-master-container {
    background: linear-gradient(135deg, var(--primary-red-dark) 0%, var(--primary-red-base) 60%, #b91c1c 100%);
    box-shadow: 0 20px 40px rgba(220, 38, 38, 0.25);
}

.cta-pulse-background-element {
    background-image: radial-gradient(circle at 50% 50%, rgba(255,255,255,0.06) 0%, transparent 60%);
}

.cta-decorative-blob {
    position: absolute;
    background-color: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-full);
    pointer-events: none;
}
.cta-decorative-blob.blob-1 { width: 300px; height: 300px; top: -100px; left: -50px; }
.cta-decorative-blob.blob-2 { width: 200px; height: 200px; bottom: -50px; right: -20px; }

/* Giant Button Engineering */
.giant-cta-action-button {
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
    animation: softButtonPulse 3s infinite;
}

.giant-cta-action-button:hover {
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 16px 32px rgba(0, 0, 0, 0.2);
    background-color: #ffffff !important;
}

.giant-cta-action-button:active {
    transform: translateY(1px);
}

.btn-shimmer-layer {
    position: absolute;
    top: 0;
    width: 40%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(220, 38, 38, 0.08), transparent);
    transform: skewX(-30deg);
    animation: btnShimmer 4s infinite linear;
}

.text-transparent-white {
    color: rgba(255, 255, 255, 0.65);
}

/* 9. Amazon Professional Style Vertically Structured Reviews Panel */
.reviews-master-panel {
    box-shadow: var(--shadow-premium-card);
}

.review-block-card {
    transition: all var(--transition-normal);
}
.review-block-card:hover {
    background-color: #fafbfc;
    border-color: var(--border-color-mid);
}

.user-avatar-frame {
    border-color: rgba(220, 38, 38, 0.1);
}

.review-date-origin {
    font-size: 0.725rem;
}

/* 10. Footers Component Architectures */
.custom-footer-block {
    background-color: #0b0f19;
}

.amazon-policies-navigation-wrapper ul {
    border-color: #161f30;
}

.policy-nav-item a:hover {
    color: #ef4444;
}

/* 11. Ultra Responsive Multi-device Breakpoints (Mobile-First Strategy) */

/* Core Mobile Optimization Tweak (Fallback below 640px) */
@media (max-width: 639px) {
    .main-product-title {
        font-size: 1.625rem;
    }
    
    .master-image-viewport {
        margin-left: auto;
        margin-right: auto;
    }
    
    .review-date-origin {
        text-align: left !important;
        margin-top: 2px;
    }
}

/* Small Desktop Breakpoints & Adjustments (>= 768px) */
@media (min-width: 768px) {
    .trust-pill-container {
        font-size: 0.8rem;
    }
}

/* Large Full Scale Grid Implementations (>= 1024px) */
@media (min-width: 1024px) {
    .main-product-card {
        transform: none;
    }
    
    .main-product-card:hover {
        transform: translateY(-2px);
    }
    
    .absolute-decor-container {
        height: 1600px;
    }
}

/* Ultra precise screen size corrections to secure layout blocks logic */
@media (max-width: 340px) {
    .trust-pill-container {
        gap: 2px;
    }
    .giant-cta-action-button {
        font-size: 0.875rem !important;
        padding-left: 1.5rem !important;
        padding-right: 1.5rem !important;
    }
}
.master-image-viewport {
    width: 100%;
    aspect-ratio: 1 / 1;
    min-height: 320px;
}

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