:root {
    --primary-color: #ffffff;
    --accent-color: #00e5ff;
    --accent-glow: rgba(0, 229, 255, 0.4);
    --bg-gradient: radial-gradient(circle at 50% 30%, #161a23 0%, #08090c 100%);
    --text-color: #f1f5f9;
    --text-muted: rgba(241, 245, 249, 0.6);
    --glass-bg: rgba(15, 23, 42, 0.65);
    --glass-border: rgba(255, 255, 255, 0.12);
    --glass-hover: rgba(255, 255, 255, 0.18);
    --card-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
}

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

body {
    font-family: var(--font-body);
    color: var(--text-color);
    background: #08090c;
    overflow: hidden;
    height: 100vh;
    width: 100vw;
    user-select: none;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #050608;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    transition: opacity 0.8s ease, visibility 0.8s ease;
}

.loading-overlay.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader-content {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.loader-brand {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: 2px;
    margin-bottom: 0.5rem;
}

.loader-brand span {
    color: var(--accent-color);
}

.loader-circle {
    width: 60px;
    height: 60px;
    border: 3px solid rgba(255, 255, 255, 0.08);
    border-top-color: var(--accent-color);
    border-radius: 50%;
    margin-bottom: 1.5rem;
    animation: spin 0.9s cubic-bezier(0.68, -0.55, 0.27, 1.55) infinite;
    box-shadow: 0 0 25px var(--accent-glow);
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.loader-content p {
    font-size: 0.85rem;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--text-muted);
}

#load-percentage {
    color: var(--accent-color);
    font-weight: 700;
    margin-left: 0.5rem;
}

/* Application Layout */
#app {
    width: 100%;
    height: 100%;
    position: relative;
    background: var(--bg-gradient);
}

#three-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

/* Floating 3D Hotspot Dynamic Container */
#hotspot-labels-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 2;
    pointer-events: none;
}

.floating-pin {
    position: absolute;
    transform: translate(-50%, -50%);
    pointer-events: auto;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: opacity 0.3s ease, transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.floating-pin .pin-dot {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-color);
    box-shadow: 0 0 15px var(--accent-color), 0 0 30px var(--accent-color);
    border: 2px solid #ffffff;
    animation: pulsePin 2s infinite;
}

@keyframes pulsePin {
    0% { box-shadow: 0 0 0 0 rgba(0, 229, 255, 0.7); }
    70% { box-shadow: 0 0 0 15px rgba(0, 229, 255, 0); }
    100% { box-shadow: 0 0 0 0 rgba(0, 229, 255, 0); }
}

.floating-pin .pin-card {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    padding: 6px 14px;
    border-radius: 30px;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    white-space: nowrap;
    box-shadow: var(--card-shadow);
    color: #ffffff;
}

.floating-pin:hover {
    transform: translate(-50%, -50%) scale(1.1);
}

/* UI Overlay */
.ui-overlay {
    position: relative;
    z-index: 3;
    pointer-events: none;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-space-between;
    padding: 1.5rem 2rem;
}

header {
    width: 100%;
    pointer-events: auto;
}

nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    padding: 0.85rem 1.75rem;
    border-radius: 100px;
    box-shadow: var(--card-shadow);
}

.logo {
    font-family: var(--font-heading);
    font-size: 1.35rem;
    font-weight: 800;
    letter-spacing: 1px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.logo span {
    color: var(--accent-color);
}

.logo .badge {
    font-size: 0.65rem;
    font-weight: 700;
    padding: 2px 8px;
    background: rgba(0, 229, 255, 0.15);
    border: 1px solid var(--accent-color);
    border-radius: 12px;
    color: var(--accent-color);
}

/* Product Selector Tabs */
.product-tabs {
    display: flex;
    background: rgba(0, 0, 0, 0.4);
    padding: 4px;
    border-radius: 30px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.tab-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    padding: 0.5rem 1.25rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-btn:hover {
    color: #ffffff;
}

.tab-btn.active {
    background: var(--accent-color);
    color: #08090c;
    box-shadow: 0 0 15px var(--accent-glow);
}

/* Studio Environment Selector */
.studio-selector {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(0, 0, 0, 0.4);
    padding: 0.4rem 1rem;
    border-radius: 30px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    font-size: 0.85rem;
    color: var(--accent-color);
}

.studio-selector select {
    background: transparent;
    border: none;
    color: var(--text-color);
    font-family: var(--font-body);
    font-size: 0.85rem;
    font-weight: 500;
    outline: none;
    cursor: pointer;
}

.studio-selector select option {
    background: #0f172a;
    color: #ffffff;
}

/* Main Sidebar Card */
main {
    max-width: 440px;
    margin-top: 1.5rem;
    position: relative;
    z-index: 5;
}

.product-info {
    pointer-events: auto;
    background: var(--glass-bg);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid var(--glass-border);
    padding: 1.75rem;
    border-radius: 1.75rem;
    box-shadow: var(--card-shadow);
    animation: slideIn 0.8s cubic-bezier(0.16, 1, 0.3, 1);
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.panel-header-mobile {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
}

.panel-toggle-btn {
    display: none;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid var(--glass-border);
    color: var(--accent-color);
    width: 32px;
    height: 32px;
    border-radius: 50%;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: transform 0.3s ease, background 0.2s ease;
}

.panel-toggle-btn:hover {
    background: rgba(0, 229, 255, 0.2);
}

.panel-toggle-btn i {
    transition: transform 0.3s ease;
}

.product-info.collapsed .panel-toggle-btn i {
    transform: rotate(180deg);
}

.panel-body {
    transition: opacity 0.3s ease, max-height 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    overflow: hidden;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.category-tag {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--accent-color);
    font-weight: 700;
    margin-bottom: 0.5rem;
}

h1 {
    font-family: var(--font-heading);
    font-size: clamp(2.0rem, 4vw, 2.75rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 0.75rem;
    letter-spacing: -1px;
    background: linear-gradient(135deg, #ffffff 0%, #cbd5e1 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

p {
    font-size: clamp(0.85rem, 1.5vw, 0.95rem);
    line-height: 1.6;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

.specs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-bottom: 1.5rem;
    background: rgba(0, 0, 0, 0.3);
    padding: 1rem;
    border-radius: 1rem;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.spec-item {
    display: flex;
    flex-direction: column;
}

.spec-item .label {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: rgba(255, 255, 255, 0.4);
    margin-bottom: 0.2rem;
}

.spec-item .value {
    font-weight: 600;
    font-size: 0.95rem;
    color: #ffffff;
}

/* Explode Control Slider */
.explode-control-container {
    margin-bottom: 1.5rem;
    background: rgba(0, 0, 0, 0.3);
    padding: 1rem;
    border-radius: 1rem;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.control-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.6rem;
}

.control-header .label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 6px;
}

.control-header .value {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--accent-color);
}

.styled-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: rgba(255, 255, 255, 0.15);
    outline: none;
    cursor: pointer;
}

.styled-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--accent-color);
    box-shadow: 0 0 10px var(--accent-color);
    cursor: pointer;
    transition: transform 0.1s ease;
}

.styled-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

/* Color Picker */
.color-picker-container {
    margin-bottom: 1.5rem;
}

.color-picker-container .label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: rgba(255, 255, 255, 0.4);
    display: block;
    margin-bottom: 0.75rem;
}

.color-options {
    display: flex;
    gap: 0.85rem;
}

.color-btn {
    width: 34px;
    height: 34px;
    border-radius: 50%;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all 0.25s ease;
    padding: 0;
    position: relative;
}

.color-btn.active {
    border-color: #ffffff;
    transform: scale(1.15);
    box-shadow: 0 0 15px rgba(255, 255, 255, 0.4);
}

.cta-button {
    width: 100%;
    padding: 1.1rem;
    background: linear-gradient(135deg, var(--accent-color) 0%, #00a8ff 100%);
    color: #08090c;
    border: none;
    border-radius: 1rem;
    font-family: var(--font-heading);
    font-size: 1.05rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 10px 30px var(--accent-glow);
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 40px rgba(0, 229, 255, 0.6);
}

/* Bottom Floating Quick Actions HUD */
.hud-actions {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 0.75rem;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 0.6rem 1rem;
    border-radius: 100px;
    border: 1px solid var(--glass-border);
    box-shadow: var(--card-shadow);
    pointer-events: auto;
}

.hud-btn {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-color);
    font-size: 1.1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.25s ease;
}

.hud-btn:hover {
    background: var(--glass-hover);
    color: var(--accent-color);
    transform: scale(1.1);
}

.hud-btn.active {
    background: var(--accent-color);
    color: #08090c;
    box-shadow: 0 0 15px var(--accent-glow);
}

/* Hotspot Detail Popup */
.hotspot-popup {
    position: absolute;
    top: 50%;
    right: 2rem;
    transform: translateY(-50%) translateX(40px);
    width: 340px;
    background: var(--glass-bg);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border: 1px solid var(--glass-border);
    padding: 2rem;
    border-radius: 1.75rem;
    z-index: 20;
    pointer-events: auto;
    opacity: 0;
    visibility: hidden;
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: var(--card-shadow);
}

.hotspot-popup.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(-50%) translateX(0);
}

.popup-badge {
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 1px;
    color: var(--accent-color);
    margin-bottom: 0.5rem;
    display: inline-block;
    padding: 2px 8px;
    background: rgba(0, 229, 255, 0.1);
    border-radius: 6px;
}

.hotspot-popup h3 {
    font-family: var(--font-heading);
    font-size: 1.4rem;
    margin-bottom: 0.5rem;
    color: #ffffff;
}

.hotspot-popup p {
    font-size: 0.9rem;
    margin-bottom: 1.25rem;
    color: var(--text-muted);
}

.popup-stats {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    background: rgba(0, 0, 0, 0.3);
    padding: 0.85rem;
    border-radius: 0.75rem;
    font-size: 0.8rem;
    color: #cbd5e1;
}

.close-popup {
    position: absolute;
    top: 1.25rem;
    right: 1.25rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    width: 32px;
    height: 32px;
    color: #fff;
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.close-popup:hover {
    background: rgba(255, 255, 255, 0.2);
}

/* Modals Overlay */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    pointer-events: auto;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: #0f172a;
    border: 1px solid var(--glass-border);
    border-radius: 1.5rem;
    padding: 2rem;
    width: 480px;
    max-width: 90%;
    box-shadow: var(--card-shadow);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.modal-header h3 {
    font-family: var(--font-heading);
    font-size: 1.3rem;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--accent-color);
}

.close-modal {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
}

.close-modal:hover {
    color: #ffffff;
}

.shortcuts-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.shortcut-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.85rem;
}

.shortcut-item kbd {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 6px;
    padding: 4px 8px;
    font-family: monospace;
    font-weight: 700;
    color: var(--accent-color);
}

/* Hints bar */
.controls-hint {
    position: absolute;
    bottom: 2rem;
    right: 2rem;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    padding: 0.6rem 1.25rem;
    border-radius: 100px;
    border: 1px solid var(--glass-border);
}

.controls-hint p {
    margin: 0;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* ==========================================
   📱 RESPONSIVE DESIGN SYSTEM & BREAKPOINTS
   ========================================== */

/* Large Screens & 4K Displays */
@media (min-width: 1600px) {
    .ui-overlay {
        padding: 2.5rem 4rem;
    }

    main {
        max-width: 500px;
    }

    h1 {
        font-size: 3.25rem;
    }

    .tab-btn {
        padding: 0.65rem 1.6rem;
        font-size: 0.95rem;
    }

    .hud-btn {
        width: 48px;
        height: 48px;
        font-size: 1.25rem;
    }
}

/* Laptops & Tablets Landscape */
@media (max-width: 1200px) {
    main {
        max-width: 400px;
    }
}

/* Tablets & Mobile Screens */
@media (max-width: 900px) {
    .ui-overlay {
        padding: 1rem;
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
    }

    nav {
        flex-direction: column;
        align-items: stretch;
        gap: 0.75rem;
        padding: 0.75rem 1rem;
        border-radius: 1.5rem;
    }

    .logo {
        justify-content: center;
    }

    .product-tabs {
        overflow-x: auto;
        white-space: nowrap;
        justify-content: flex-start;
        padding: 4px;
        scrollbar-width: none;
        -ms-overflow-style: none;
        width: 100%;
    }

    .product-tabs::-webkit-scrollbar {
        display: none;
    }

    .tab-btn {
        padding: 0.45rem 1rem;
        font-size: 0.8rem;
        flex-shrink: 0;
    }

    .studio-selector {
        justify-content: center;
        width: 100%;
    }

    main {
        max-width: 100%;
        margin-top: 0.75rem;
    }

    .product-info {
        padding: 1.25rem;
        border-radius: 1.25rem;
        max-height: calc(100vh - 200px);
        max-height: calc(100dvh - 200px);
        overflow-y: auto;
        scrollbar-width: thin;
        scrollbar-color: rgba(0, 229, 255, 0.3) transparent;
    }

    .product-info::-webkit-scrollbar {
        width: 4px;
    }

    .product-info::-webkit-scrollbar-thumb {
        background: rgba(0, 229, 255, 0.4);
        border-radius: 4px;
    }

    .panel-toggle-btn {
        display: flex;
    }

    .product-info.collapsed .panel-body {
        max-height: 0 !important;
        opacity: 0 !important;
        overflow: hidden !important;
        padding-top: 0 !important;
        margin: 0 !important;
        pointer-events: none;
    }

    .product-info.collapsed {
        padding-bottom: 0.75rem;
    }

    p {
        margin-bottom: 1rem;
    }

    .specs {
        gap: 0.75rem;
        padding: 0.75rem;
        margin-bottom: 1rem;
    }

    .spec-item .value {
        font-size: 0.88rem;
    }

    .explode-control-container,
    .color-picker-container {
        margin-bottom: 1rem;
        padding: 0.75rem;
    }

    .hud-actions {
        bottom: 1rem;
        padding: 0.4rem 0.6rem;
        gap: 0.4rem;
        max-width: 95vw;
        overflow-x: auto;
        scrollbar-width: none;
        justify-content: flex-start;
        border-radius: 30px;
        -webkit-overflow-scrolling: touch;
    }

    .hud-actions::-webkit-scrollbar {
        display: none;
    }

    .hud-btn {
        width: 38px;
        height: 38px;
        font-size: 0.95rem;
        flex-shrink: 0;
    }

    .hotspot-popup {
        right: 1rem;
        left: 1rem;
        width: auto;
        top: auto;
        bottom: 4.5rem;
        transform: translateY(40px);
        padding: 1.25rem;
        border-radius: 1.25rem;
        max-height: 50vh;
        overflow-y: auto;
    }

    .hotspot-popup.active {
        transform: translateY(0);
    }

    .controls-hint {
        display: none;
    }
}

/* Small Mobile Screens (480px & below) */
@media (max-width: 480px) {
    .ui-overlay {
        padding: 0.65rem;
    }

    nav {
        padding: 0.6rem 0.85rem;
        border-radius: 1.25rem;
    }

    .logo {
        font-size: 1.15rem;
    }

    .tab-btn {
        padding: 0.4rem 0.8rem;
        font-size: 0.75rem;
    }

    .product-info {
        padding: 1rem;
    }

    .specs {
        grid-template-columns: 1fr 1fr;
    }

    .color-options {
        gap: 0.5rem;
        flex-wrap: wrap;
    }

    .color-btn {
        width: 30px;
        height: 30px;
    }

    .cta-button {
        padding: 0.85rem;
        font-size: 0.92rem;
    }

    .modal-content {
        padding: 1.25rem;
        width: 94vw;
        border-radius: 1.25rem;
    }

    .shortcuts-grid {
        grid-template-columns: 1fr;
        gap: 0.65rem;
    }
}