/* ==========================================================================
   CSS VARIABLES - ROOT THEME (Строго синяя палитра)
   ========================================================================== */
:root {
    /* Color Palette - Core Blues */
    --clr-blue-50:  #f0f9ff;
    --clr-blue-100: #e0f2fe;
    --clr-blue-200: #bae6fd;
    --clr-blue-300: #7dd3fc;
    --clr-blue-400: #38bdf8;
    --clr-blue-500: #0ea5e9;
    --clr-blue-600: #0284c7;
    --clr-blue-700: #0369a1;
    --clr-blue-800: #075985;
    --clr-blue-900: #0c4a6e;
    --clr-blue-950: #082f49;

    /* Accent Colors (masih dalam spektrum biru/neutral) */
    --clr-accent-main: var(--clr-blue-600);
    --clr-accent-hover: var(--clr-blue-500);
    --clr-accent-light: var(--clr-blue-400);
    --clr-accent-dark: var(--clr-blue-800);
    
    /* Neutral / Text / Surface Colors */
    --clr-surface-white: #ffffff;
    --clr-surface-off: #f8fafc;
    --clr-surface-dark: #0f172a;
    --clr-text-main: #1e293b;
    --clr-text-muted: #64748b;
    --clr-text-light: #94a3b8;

    /* Gradients */
    --grad-primary: linear-gradient(135deg, var(--clr-blue-800) 0%, var(--clr-blue-600) 100%);
    --grad-secondary: linear-gradient(135deg, var(--clr-blue-600) 0%, var(--clr-blue-400) 100%);
    --grad-surface: linear-gradient(180deg, var(--clr-surface-white) 0%, var(--clr-blue-50) 100%);
    --grad-card: linear-gradient(145deg, #ffffff 0%, #f8fafc 100%);
    --grad-glow: radial-gradient(circle at center, rgba(56, 189, 248, 0.4) 0%, rgba(2, 132, 199, 0) 70%);

    /* Shadows (Layered for depth) */
    --shadow-soft: 0 4px 20px -2px rgba(12, 74, 110, 0.05);
    --shadow-medium: 0 10px 30px -5px rgba(12, 74, 110, 0.08), 0 4px 10px -5px rgba(12, 74, 110, 0.04);
    --shadow-heavy: 0 20px 40px -10px rgba(12, 74, 110, 0.15), 0 10px 20px -10px rgba(12, 74, 110, 0.1);
    --shadow-inner-glow: inset 0 2px 10px rgba(255, 255, 255, 0.8), inset 0 -2px 10px rgba(14, 165, 233, 0.05);
    --shadow-cta: 0 15px 35px -10px rgba(2, 132, 199, 0.4), 0 5px 15px -5px rgba(2, 132, 199, 0.3);
    --shadow-cta-hover: 0 20px 45px -10px rgba(2, 132, 199, 0.5), 0 10px 20px -5px rgba(2, 132, 199, 0.4);

    /* Borders & Radius */
    --radius-sm: 0.5rem;
    --radius-md: 1rem;
    --radius-lg: 1.5rem;
    --radius-xl: 2.5rem;
    --border-light: 1px solid rgba(14, 165, 233, 0.1);

    /* Typography & Transitions */
    --font-primary: 'Inter', system-ui, -apple-system, sans-serif;
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ==========================================================================
   RESET & BASE STYLES
   ========================================================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    background-color: var(--clr-surface-off);
    color: var(--clr-text-main);
    overflow-x: hidden;
    line-height: 1.6;
}

/* Custom Selection */
::selection {
    background-color: var(--clr-blue-200);
    color: var(--clr-blue-900);
}

/* Custom Scrollbar (Webkit) */
::-webkit-scrollbar {
    width: 10px;
}
::-webkit-scrollbar-track {
    background: var(--clr-surface-off);
}
::-webkit-scrollbar-thumb {
    background: var(--clr-blue-300);
    border-radius: var(--radius-sm);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--clr-blue-500);
}

/* ==========================================================================
   DECORATIVE BACKGROUNDS (CSS ONLY)
   ========================================================================== */
.bg-decor-wrapper {
    position: fixed;
    inset: 0;
    z-index: 0;
    overflow: hidden;
    pointer-events: none;
    background: var(--grad-surface);
}

.bg-blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    z-index: 1;
}

.bg-blob-1 {
    top: -10%;
    left: -10%;
    width: 50vw;
    height: 50vw;
    background: radial-gradient(circle, var(--clr-blue-200) 0%, transparent 70%);
    animation: floatBlob 20s ease-in-out infinite alternate;
}

.bg-blob-2 {
    bottom: -10%;
    right: -10%;
    width: 60vw;
    height: 60vw;
    background: radial-gradient(circle, var(--clr-blue-100) 0%, transparent 70%);
    animation: floatBlob 25s ease-in-out infinite alternate-reverse;
}

.bg-pattern-overlay {
    position: absolute;
    inset: 0;
    z-index: 2;
    opacity: 0.15;
    background-image: 
        linear-gradient(var(--clr-blue-200) 1px, transparent 1px),
        linear-gradient(90deg, var(--clr-blue-200) 1px, transparent 1px);
    background-size: 40px 40px;
    mask-image: radial-gradient(circle at center, black 40%, transparent 100%);
    -webkit-mask-image: radial-gradient(circle at center, black 40%, transparent 100%);
}

@keyframes floatBlob {
    0% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(3%, 5%) scale(1.05); }
    100% { transform: translate(-3%, -5%) scale(0.95); }
}

/* ==========================================================================
   HEADER STYLES
   ========================================================================== */
.site-header {
    background: rgba(255, 255, 255, 0.75);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.5);
    box-shadow: 0 4px 30px rgba(12, 74, 110, 0.03);
}

.header-glow {
    background: linear-gradient(90deg, transparent 0%, var(--clr-blue-300) 50%, transparent 100%);
    opacity: 0.5;
}

.brand-badge {
    color: var(--clr-blue-600);
    letter-spacing: 0.15em;
    position: relative;
    display: inline-block;
}

.brand-badge::before,
.brand-badge::after {
    content: '';
    position: absolute;
    top: 50%;
    width: 20px;
    height: 1px;
    background-color: var(--clr-blue-300);
}

.brand-badge::before { left: -30px; }
.brand-badge::after { right: -30px; }

.header-title {
    color: var(--clr-blue-950);
    text-shadow: 0 2px 4px rgba(255,255,255,0.5);
    background: linear-gradient(to right, var(--clr-blue-950), var(--clr-blue-700));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* ==========================================================================
   PRODUCT CARD (HERO)
   ========================================================================== */
.product-card {
    background: var(--grad-card);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-heavy), var(--shadow-inner-glow);
    border: var(--border-light);
    transform-style: preserve-3d;
    perspective: 1000px;
    padding: 1rem;
}

/* Corner Accents */
.card-corner-accent {
    position: absolute;
    width: 150px;
    height: 150px;
    pointer-events: none;
    z-index: 0;
}

.card-corner-accent.top-left {
    top: 0;
    left: 0;
    background: radial-gradient(circle at 0 0, rgba(56, 189, 248, 0.15) 0%, transparent 70%);
}

.card-corner-accent.bottom-right {
    bottom: 0;
    right: 0;
    background: radial-gradient(circle at 100% 100%, rgba(2, 132, 199, 0.1) 0%, transparent 70%);
}

/* ==========================================================================
   CSS-ONLY GALLERY LOGIC & STYLING
   ========================================================================== */
.product-gallery-container {
    background: rgba(255,255,255,0.6);
    border-radius: var(--radius-lg);
    padding: 1rem;
    box-shadow: inset 0 2px 10px rgba(12, 74, 110, 0.02);
}

.gallery-main-view {
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, #ffffff 0%, var(--clr-blue-50) 100%);
    box-shadow: var(--shadow-inner-glow), inset 0 0 0 1px rgba(14, 165, 233, 0.05);
}

.main-img-wrapper {
    opacity: 0;
    visibility: hidden;
    transform: scale(0.95);
    transition: opacity var(--transition-slow), transform var(--transition-bounce), visibility var(--transition-slow);
}

.main-img-wrapper img {
    max-height: 100%;
    max-width: 100%;
    transition: transform var(--transition-slow);
}

/* Hover Zoom Effect on Main Image */
.main-img-wrapper:hover img {
    transform: scale(1.05);
}

/* Gallery Inputs Logic */
#img-1:checked ~ .gallery-main-view .wrapper-1,
#img-2:checked ~ .gallery-main-view .wrapper-2,
#img-3:checked ~ .gallery-main-view .wrapper-3,
#img-4:checked ~ .gallery-main-view .wrapper-4 {
    opacity: 1;
    visibility: visible;
    transform: scale(1);
    z-index: 10;
}

/* Thumbnail Styling */
.thumb-item {
    border-radius: var(--radius-sm);
    border: 2px solid transparent;
    box-shadow: var(--shadow-soft);
    transition: all var(--transition-base);
}

.thumb-overlay {
    background-color: rgba(255, 255, 255, 0.4);
}

.thumb-item:hover .thumb-overlay {
    opacity: 0;
}

.thumb-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

/* Active Thumbnail Logic */
#img-1:checked ~ .gallery-thumbnails label[for="img-1"],
#img-2:checked ~ .gallery-thumbnails label[for="img-2"],
#img-3:checked ~ .gallery-thumbnails label[for="img-3"],
#img-4:checked ~ .gallery-thumbnails label[for="img-4"] {
    border-color: var(--clr-blue-500);
    box-shadow: 0 0 0 4px rgba(14, 165, 233, 0.2);
    transform: translateY(-2px);
}

#img-1:checked ~ .gallery-thumbnails label[for="img-1"] .thumb-overlay,
#img-2:checked ~ .gallery-thumbnails label[for="img-2"] .thumb-overlay,
#img-3:checked ~ .gallery-thumbnails label[for="img-3"] .thumb-overlay,
#img-4:checked ~ .gallery-thumbnails label[for="img-4"] .thumb-overlay {
    opacity: 0;
}

/* ==========================================================================
   PRODUCT DESCRIPTION (RIGHT SIDE)
   ========================================================================== */
.product-main-title {
    position: relative;
    z-index: 1;
}

.title-separator {
    background: var(--grad-primary);
    box-shadow: 0 2px 10px rgba(2, 132, 199, 0.3);
}

.feature-item {
    background: rgba(255, 255, 255, 0.5);
    padding: 1rem;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    transition: all var(--transition-base);
}

.feature-item:hover {
    background: #ffffff;
    border-color: rgba(14, 165, 233, 0.15);
    box-shadow: var(--shadow-soft);
    transform: translateX(5px);
}

.feature-icon-wrapper {
    color: var(--clr-blue-600);
    background: var(--clr-blue-50);
    padding: 0.5rem;
    border-radius: 50%;
    box-shadow: inset 0 2px 4px rgba(255,255,255,0.8), 0 2px 5px rgba(12, 74, 110, 0.05);
}

.feature-highlight {
    color: var(--clr-blue-900);
    margin-right: 0.25rem;
}

/* ==========================================================================
   CALL TO ACTION SECTION
   ========================================================================== */
.cta-section {
    perspective: 1000px;
}

.cta-background {
    background: radial-gradient(ellipse at center, rgba(14, 165, 233, 0.1) 0%, transparent 70%);
    filter: blur(20px);
}

.cta-button {
    background: var(--grad-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-cta);
    transition: all var(--transition-bounce);
    transform: translateZ(0); /* Hardware acceleration */
}

.cta-button:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: var(--shadow-cta-hover);
    background: linear-gradient(135deg, var(--clr-blue-700) 0%, var(--clr-blue-500) 100%);
}

.cta-button:active {
    transform: translateY(2px) scale(0.98);
    box-shadow: var(--shadow-soft);
}

.cta-shine {
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    transform: skewX(-20deg) translateX(-150%);
}

.cta-button:hover .cta-shine {
    animation: shineSweep 1.5s ease-in-out infinite;
}

@keyframes shineSweep {
    0% { transform: skewX(-20deg) translateX(-150%); }
    100% { transform: skewX(-20deg) translateX(250%); }
}

@keyframes bounce-slow {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-3px); }
}

.animate-bounce-slow {
    animation: bounce-slow 2s infinite ease-in-out;
}

/* ==========================================================================
   REVIEWS SECTION (AMAZON STYLE BUT ENHANCED)
   ========================================================================== */
.reviews-title {
    display: inline-block;
}

.reviews-title-underline {
    width: 60%;
    height: 4px;
    background: var(--grad-secondary);
    border-radius: 2px;
}

.review-card {
    background: var(--clr-surface-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(14, 165, 233, 0.05);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

/* Hover Effect for Card */
.review-card::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: var(--grad-primary);
    transform: scaleY(0);
    transform-origin: center;
    transition: transform var(--transition-base);
}

.review-card:hover {
    box-shadow: var(--shadow-medium);
    transform: translateY(-3px);
}

.review-card:hover::before {
    transform: scaleY(1);
}

/* Avatar Styling */
.review-avatar-wrapper {
    padding: 3px;
    background: linear-gradient(135deg, var(--clr-blue-200), var(--clr-blue-50));
    border-radius: 50%;
    box-shadow: 0 4px 10px rgba(12, 74, 110, 0.08);
}

.review-avatar {
    border-radius: 50%;
    border: 2px solid var(--clr-surface-white);
}

/* Stars */
.text-accent-blue {
    color: var(--clr-blue-500);
}

/* Typography in Reviews */
.review-title {
    font-size: 1.05rem;
    color: var(--clr-blue-950);
}

.review-date {
    font-size: 0.85rem;
}

.review-body {
    font-size: 0.95rem;
    color: var(--clr-text-main);
    background: var(--clr-surface-off);
    padding: 1rem;
    border-radius: var(--radius-md);
    border-left: 3px solid var(--clr-blue-200);
}

/* ==========================================================================
   FOOTER STYLES
   ========================================================================== */
.site-footer {
    background-color: var(--clr-surface-white);
    box-shadow: 0 -10px 40px rgba(12, 74, 110, 0.03);
    margin-top: 4rem;
}

.footer-top-border {
    background: linear-gradient(90deg, var(--clr-blue-200) 0%, var(--clr-blue-500) 50%, var(--clr-blue-200) 100%);
    opacity: 0.7;
}

.footer-brand {
    color: var(--clr-blue-900);
}

.footer-link {
    color: var(--clr-text-muted);
    font-weight: 500;
    font-size: 0.9rem;
    text-decoration: none;
    position: relative;
    padding: 0.5rem 0;
    transition: color var(--transition-fast);
}

.footer-link:hover {
    color: var(--clr-blue-600);
}

.link-hover-line {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--clr-blue-500);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform var(--transition-base);
}

.footer-link:hover .link-hover-line {
    transform: scaleX(1);
    transform-origin: left;
}

.footer-separator {
    background-color: var(--clr-blue-200);
}

.footer-copy {
    color: var(--clr-text-light);
}

/* ==========================================================================
   RESPONSIVE MEDIA QUERIES (Mobile-First Adjustments)
   ========================================================================== */

/* Extra Small Devices (320px - 374px) */
@media (max-width: 374px) {
    .header-title { font-size: 1.25rem; }
    .product-main-title { font-size: 1.75rem; }
    .cta-button { width: 100%; font-size: 1.1rem; padding: 1rem; }
    .review-card { padding: 1rem; }
}

/* Small Devices (Mobile) */
@media (max-width: 767px) {
    .product-card {
        padding: 0.5rem;
        border-radius: var(--radius-lg);
    }
    .gallery-main-view {
        border-radius: var(--radius-sm);
    }
    .footer-links {
        flex-direction: column;
        gap: 1rem;
    }
    .review-rating-row {
        flex-direction: column;
        align-items: flex-start;
    }
    .review-avatar-col {
        border-bottom: 1px solid var(--clr-blue-50);
        padding-bottom: 1rem;
    }
    .feature-item {
        padding: 0.75rem;
    }
}

/* Tablet / Desktop Overrides */
@media (min-width: 768px) {
    .product-card {
        padding: 2.5rem;
    }
    .feature-item {
        padding: 1.25rem;
    }
    .review-body {
        font-size: 1rem;
    }
}

@media (min-width: 1024px) {
    .product-card {
        padding: 3.5rem;
    }
    .gallery-thumbnails {
        justify-content: flex-start;
        padding-left: 0;
    }
    .title-separator {
        margin-left: 0; /* Left align on desktop */
    }
}

/* Accessibility: Focus Visible */
*:focus-visible {
    outline: 2px dashed var(--clr-blue-500);
    outline-offset: 4px;
}

/* Print Styles */
@media print {
    .bg-decor-wrapper, .cta-section { display: none; }
    .product-card, .review-card { box-shadow: none; border: 1px solid #ccc; }
    body { background: white; color: black; }
}
.gallery-main-view {
    width: 100%;
    aspect-ratio: 1 / 1;
    min-height: 320px;
}

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