:root {
            --cream: #f7edd8;
            --cream-dark: #e8d9bf;
            --brown: #2a1f10;
            --brown-light: #4d3b28;
            --rust: #b5322a;
            --rust-light: #d4453d;
            --gold: #d4a04a;
            --gold-light: #e8bc5e;
            --tan: #b89a6a;
            --forest: #2d6b4f;
            --warm-white: #faf0dc;
            --mustard: #e6a817;
            --terracotta: #c65d2a;
            --sage: #6b9e6e;
            --dusty-rose: #c4887a;
            --warm-gray: #a89a8c;
            --paper: #f0e2c6;
            --teal: #1a7a7a;
            --vinyl-black: #111111;
            --honey: #d4882a;
            --neon-red: #ff3b3b;
            --vintage-red: #b5322a;
            --deep-amber: #c47a20;
        }

        [data-theme="dark"] {
            --cream: #17130e;
            --cream-dark: #2a231a;
            --brown: #f0e4d1;
            --brown-light: #d4c8b0;
            --warm-white: #1c170f;
            --paper: #231d14;
            --tan: #cbb894;
            --teal: #2ab5a0;
            --honey: #e8a030;
            --vintage-red: #e04444;
            --gold-light: #e6c87a;
        }

        /* ===== GRAIN OVERLAY ===== */
        body::before {
            content: '';
            position: fixed;
            inset: 0;
            background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
            opacity: 0.07;
            pointer-events: none;
            z-index: 10000;
            mix-blend-mode: multiply;
        }

        /* ===== SELECTION ===== */
        ::selection {
            background: var(--terracotta);
            color: #fff;
        }

        /* ===== PROGRESS BAR ===== */
        .reading-progress {
            position: fixed;
            top: 0;
            left: 0;
            width: 0%;
            height: 3px;
            background: linear-gradient(90deg, var(--terracotta), var(--mustard));
            z-index: 10000;
            transition: width 0.1s linear;
        }

        /* ===== SCROLL ANIMATIONS ===== */
        .v101-section,
        .v101-hero,
        .toc {
            opacity: 0;
            transform: translateY(30px);
            transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1), transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
        }
        .v101-section.visible,
        .v101-hero.visible,
        .toc.visible {
            opacity: 1;
            transform: translateY(0);
        }

        /* ===== VINYL SPIN ANIMATION ===== */
        @keyframes vinylSpin {
            from { transform: rotate(0deg); }
            to { transform: rotate(360deg); }
        }
        .vinyl-spinning {
            animation: vinylSpin 4s linear infinite;
            transform-origin: center;
        }

        /* ===== DID YOU KNOW FLOATING CARD ===== */
        .fun-fact-card {
            position: fixed;
            bottom: 24px;
            right: 24px;
            background: var(--cream);
            border: 1px solid var(--cream-dark);
            border-radius: 16px;
            padding: 20px 24px;
            max-width: 300px;
            box-shadow: 0 12px 40px rgba(0,0,0,0.12);
            z-index: 900;
            opacity: 0;
            transform: translateY(20px);
            transition: opacity 0.5s ease, transform 0.5s ease;
            pointer-events: none;
        }
        .fun-fact-card.show {
            opacity: 1;
            transform: translateY(0);
            pointer-events: auto;
        }
        .fun-fact-card .fact-label {
            font-family: 'Space Mono', monospace;
            font-size: 0.6rem;
            letter-spacing: 0.15em;
            text-transform: uppercase;
            color: var(--terracotta);
            margin-bottom: 8px;
            display: flex;
            align-items: center;
            gap: 6px;
        }
        .fun-fact-card .fact-label svg {
            flex-shrink: 0;
        }
        .fun-fact-card .fact-text {
            font-family: 'Nunito', sans-serif;
            font-size: 0.85rem;
            color: var(--brown);
            line-height: 1.6;
        }
        .fun-fact-card .fact-close {
            position: absolute;
            top: 8px;
            right: 10px;
            background: none;
            border: none;
            font-size: 1rem;
            cursor: pointer;
            color: var(--brown-light);
            opacity: 0.5;
            transition: opacity 0.2s;
        }
        .fun-fact-card .fact-close:hover { opacity: 1; }
        [data-theme="dark"] .fun-fact-card {
            background: #231d14;
            border-color: #2d2418;
            box-shadow: 0 12px 40px rgba(0,0,0,0.35);
        }

        /* ===== NUMBER COUNTER ANIMATION ===== */
        .size-card h3 .counter-num {
            display: inline-block;
            font-variant-numeric: tabular-nums;
        }

        /* ===== QUIZ SECTION ===== */
        .quiz-container {
            max-width: 700px;
            margin: 0 auto;
        }
        .quiz-question {
            background: var(--warm-white);
            border: 1px solid var(--cream-dark);
            border-radius: 16px;
            padding: 32px;
            margin-bottom: 24px;
            transition: all 0.3s;
            color: var(--brown);
        }
        [data-theme="dark"] .quiz-question {
            background: var(--cream-dark);
            border-color: rgba(255,255,255,0.08);
        }
        .quiz-question .q-number {
            font-family: 'Space Mono', monospace;
            font-size: 0.65rem;
            letter-spacing: 0.15em;
            text-transform: uppercase;
            color: var(--terracotta);
            margin-bottom: 12px;
        }
        .quiz-question h3 {
            font-family: 'Playfair Display', serif;
            font-size: 1.15rem;
            font-weight: 600;
            margin-bottom: 20px;
            line-height: 1.4;
            color: var(--brown);
        }
        .quiz-options {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }
        .quiz-option {
            display: flex;
            align-items: center;
            gap: 12px;
            padding: 14px 18px;
            border: 1px solid var(--cream-dark);
            border-radius: 100px;
            cursor: pointer;
            transition: all 0.3s;
            font-family: 'Nunito', sans-serif;
            font-size: 0.9rem;
            color: var(--brown);
            background: transparent;
            user-select: none;
        }
        [data-theme="dark"] .quiz-option {
            border-color: rgba(255,255,255,0.1);
        }
        .quiz-option:hover:not(.disabled) {
            border-color: var(--terracotta);
            background: rgba(201, 111, 60, 0.06);
        }
        .quiz-option .option-letter {
            width: 28px;
            height: 28px;
            border-radius: 50%;
            background: var(--cream-dark);
            display: flex;
            align-items: center;
            justify-content: center;
            font-family: 'Space Mono', monospace;
            font-size: 0.7rem;
            font-weight: 700;
            flex-shrink: 0;
            transition: all 0.3s;
            color: var(--brown);
        }
        [data-theme="dark"] .quiz-option .option-letter {
            background: rgba(255,255,255,0.08);
        }
        .quiz-option.correct {
            border-color: var(--sage);
            background: rgba(143, 168, 138, 0.1);
        }
        .quiz-option.correct .option-letter {
            background: var(--sage);
            color: white;
        }
        .quiz-option.wrong {
            border-color: var(--dusty-rose);
            background: rgba(196, 154, 138, 0.1);
        }
        .quiz-option.wrong .option-letter {
            background: var(--dusty-rose);
            color: white;
        }
        .quiz-option.disabled {
            cursor: default;
            opacity: 0.6;
        }
        .quiz-option.correct.disabled,
        .quiz-option.wrong.disabled {
            opacity: 1;
        }
        .quiz-result {
            text-align: center;
            padding: 40px 32px;
            background: var(--warm-white);
            border: 1px solid var(--cream-dark);
            border-radius: 16px;
            display: none;
            color: var(--brown);
        }
        [data-theme="dark"] .quiz-result {
            background: var(--cream-dark);
            border-color: rgba(255,255,255,0.08);
        }
        .quiz-result.show { display: block; }
        .quiz-result .score-number {
            font-family: 'Playfair Display', serif;
            font-size: 3.5rem;
            font-weight: 700;
            color: var(--terracotta);
            line-height: 1;
            margin-bottom: 8px;
        }
        .quiz-result .score-label {
            font-family: 'Space Mono', monospace;
            font-size: 0.65rem;
            letter-spacing: 0.15em;
            text-transform: uppercase;
            color: var(--brown-light);
            margin-bottom: 20px;
        }
        .quiz-result .score-message {
            font-size: 1.05rem;
            color: var(--brown-light);
            line-height: 1.7;
            max-width: 450px;
            margin: 0 auto 24px;
        }
        .quiz-retry-btn {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 14px 28px;
            background: var(--terracotta);
            color: white;
            border: none;
            border-radius: 100px;
            font-family: 'Nunito', sans-serif;
            font-size: 0.8rem;
            font-weight: 600;
            letter-spacing: 0.08em;
            text-transform: uppercase;
            cursor: pointer;
            transition: all 0.3s;
        }
        .quiz-retry-btn:hover {
            background: var(--mustard);
            color: var(--brown);
            transform: translateY(-2px);
        }

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

        html {
            overflow-x: clip;
        }

        body {
            min-width: 1400px;
            font-family: 'Nunito', sans-serif;
            background: var(--cream);
            color: var(--brown);
            transition: background 0.3s, color 0.3s;
        }

        /* ===== HEADER ===== */
        header {
            position: sticky;
            top: 38px;
            z-index: 1000;
            padding: 20px 50px;
            display: grid;
            grid-template-columns: auto 1fr auto;
            align-items: center;
            background: var(--cream);
            border-bottom: 2px solid var(--cream-dark);
            transition: background 0.3s, border-color 0.3s;
            box-shadow: 0 2px 20px rgba(42, 31, 16, 0.08);
            min-width: 1400px;
        }

        [data-theme="dark"] header {
            background: #17130e;
            border-color: #2d2418;
        }

        .logo {
            font-family: 'Playfair Display', serif;
            font-size: 1.8rem;
            font-weight: 700;
            letter-spacing: 0.04em;
            color: var(--brown);
            text-decoration: none;
            transition: color 0.3s, text-shadow 0.3s;
            text-shadow: 1px 1px 0 rgba(212, 160, 74, 0.3);
        }

        .logo:hover { color: var(--terracotta); text-shadow: 2px 2px 0 rgba(198, 93, 42, 0.25); }

        .logo .tagline {
            display: block;
            font-family: 'Nunito', sans-serif;
            font-size: 0.55rem;
            font-weight: 400;
            letter-spacing: 0.15em;
            text-transform: uppercase;
            color: var(--terracotta);
            text-shadow: none;
            margin-top: -2px;
        }

        /* ===== HERO ===== */
        .v101-hero {
            text-align: center;
            padding: 80px 50px 60px;
            position: relative;
            overflow: hidden;
            background: var(--cream);
            color: var(--brown);
        }

        .v101-hero > * {
            position: relative;
            z-index: 1;
        }

        .v101-hero-tag {
            font-family: 'Space Mono', monospace;
            font-size: 0.7rem;
            letter-spacing: 0.25em;
            text-transform: uppercase;
            color: var(--terracotta);
            margin-bottom: 20px;
            position: relative;
            z-index: 1;
        }

        .v101-hero h1 {
            font-family: 'Playfair Display', serif;
            font-size: clamp(2.5rem, 5vw, 4rem);
            font-weight: 400;
            line-height: 1.1;
            margin-bottom: 20px;
            position: relative;
            z-index: 1;
            color: var(--brown);
        }

        .v101-hero h1 em {
            font-style: italic;
            color: var(--terracotta);
        }

        .v101-hero p {
            font-size: 1.05rem;
            color: var(--brown-light);
            max-width: 600px;
            margin: 0 auto;
            line-height: 1.8;
            position: relative;
            z-index: 1;
        }

        /* ===== TABLE OF CONTENTS ===== */
        .toc {
            display: flex;
            justify-content: center;
            gap: 12px;
            flex-wrap: wrap;
            padding: 0 50px 60px;
            z-index: 999;
            transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1), transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
        }

        .toc.sticky {
            position: fixed;
            top: var(--header-height, 73px);
            left: 0;
            right: 0;
            padding: 10px 20px;
            background: var(--cream);
            border-bottom: 1px solid var(--cream-dark);
            box-shadow: 0 4px 16px rgba(0,0,0,0.08);
            z-index: 999;
            gap: 8px;
            animation: tocSlideDown 0.3s ease-out;
        }

        .toc.sticky a {
            padding: 6px 14px;
            font-size: 0.62rem;
        }

        .toc.sticky a.active {
            border-color: var(--terracotta);
            color: var(--terracotta);
            background: rgba(201, 111, 60, 0.08);
        }

        [data-theme="dark"] .toc.sticky {
            background: var(--cream);
            border-color: #2d2418;
            box-shadow: 0 4px 16px rgba(0,0,0,0.4);
        }

        /* When TOC is sticky, merge with header visually */
        header.toc-attached {
            border-bottom-color: transparent;
            box-shadow: none;
        }

        @keyframes tocSlideDown {
            from { opacity: 0; transform: translateY(-8px); }
            to { opacity: 1; transform: translateY(0); }
        }

        /* Placeholder to prevent layout jump when TOC goes fixed */
        .toc-placeholder {
            display: none;
        }
        .toc-placeholder.active {
            display: block;
        }

        .toc a {
            font-family: 'Space Mono', monospace;
            font-size: 0.7rem;
            letter-spacing: 0.08em;
            text-transform: uppercase;
            color: var(--brown-light);
            text-decoration: none;
            padding: 10px 20px;
            border: 1px solid var(--cream-dark);
            border-radius: 100px;
            transition: all 0.3s;
        }

        .toc a:hover {
            border-color: var(--terracotta);
            color: var(--terracotta);
            background: rgba(201, 111, 60, 0.05);
        }

        [data-theme="dark"] .toc a {
            border-color: #2d2418;
        }

        /* ===== SECTIONS ===== */
        .v101-section {
            padding: 80px 50px;
            max-width: none;
            margin: 0 auto;
            position: relative;
            color: var(--cream);
        }

        .v101-section > * {
            position: relative;
            z-index: 1;
        }

        .v101-section > .section-header,
        .v101-section > .parts-grid,
        .v101-section > .blueprint-container,
        .v101-section > .record-anatomy,
        .v101-section > .sizes-grid,
        .v101-section > .rpm-cards,
        .v101-section > .steps,
        .v101-section > .care-grid,
        .v101-section > .glossary-grid,
        .v101-section > .quiz-container {
            max-width: 1100px;
            margin-left: auto;
            margin-right: auto;
        }

        /* Section photo backgrounds */
        #anatomy {
            background: url('../images/detail-leadin.jpg') center/cover no-repeat;
        }
        #anatomy::before {
            content: '';
            position: absolute;
            inset: 0;
            background: rgba(30, 22, 10, 0.88);
            z-index: 0;
            pointer-events: none;
        }
        #record {
            background: var(--cream);
            color: var(--brown);
        }
        #sizes {
            background: url('../images/vinyl101-sizes-bg.jpg') center/cover no-repeat;
        }
        #sizes::before {
            content: '';
            position: absolute;
            inset: 0;
            background: rgba(30, 22, 10, 0.88);
            z-index: 0;
            pointer-events: none;
        }
        #rpm {
            background: var(--cream);
            color: var(--brown);
        }
        #howto {
            background: url('../images/part-cueing.jpg') center/cover no-repeat;
        }
        #howto::before {
            content: '';
            position: absolute;
            inset: 0;
            background: rgba(30, 22, 10, 0.88);
            z-index: 0;
            pointer-events: none;
        }
        #care {
            background: var(--cream);
            color: var(--brown);
        }
        #glossary {
            background: url('../images/about-team-curator.jpg') center/cover no-repeat;
        }
        #glossary::before {
            content: '';
            position: absolute;
            inset: 0;
            background: rgba(30, 22, 10, 0.88);
            z-index: 0;
            pointer-events: none;
        }
        #quiz {
            background: var(--cream);
            color: var(--brown);
        }

        /* Dark mode: increase overlay opacity for sections with backgrounds */
        [data-theme="dark"] #anatomy::before,
        [data-theme="dark"] #sizes::before,
        [data-theme="dark"] #howto::before,
        [data-theme="dark"] #glossary::before {
            background: rgba(30, 22, 10, 0.92);
        }

        /* Override text colors for sections without photo backgrounds (plain cream) */
        #record .section-number,
        #rpm .section-number,
        #care .section-number,
        #quiz .section-number {
            color: var(--terracotta);
        }
        #record .section-header h2,
        #rpm .section-header h2,
        #care .section-header h2,
        #quiz .section-header h2 {
            color: var(--brown);
        }
        #record .section-header h2 em,
        #rpm .section-header h2 em,
        #care .section-header h2 em,
        #quiz .section-header h2 em {
            color: var(--terracotta);
        }
        #record .section-header p,
        #rpm .section-header p,
        #care .section-header p,
        #quiz .section-header p {
            color: var(--brown-light);
        }

        .section-header {
            text-align: center;
            margin-bottom: 60px;
        }

        .section-number {
            font-family: 'Space Mono', monospace;
            font-size: 0.65rem;
            letter-spacing: 0.2em;
            text-transform: uppercase;
            color: var(--gold-light);
            margin-bottom: 12px;
        }

        .section-header h2 {
            font-family: 'Playfair Display', serif;
            font-size: clamp(1.8rem, 4vw, 2.8rem);
            font-weight: 400;
            color: #fff;
        }

        .section-header h2 em {
            font-style: italic;
            color: var(--gold-light);
        }

        .section-header p {
            color: var(--tan);
            font-size: 0.95rem;
            max-width: 550px;
            margin: 15px auto 0;
            line-height: 1.7;
        }

        /* ===== TURNTABLE BLUEPRINT ===== */
        .blueprint-container {
            position: relative;
            max-width: 900px;
            margin: 0 auto 60px;
            background: rgba(23, 19, 14, 0.7);
            border: 2px solid rgba(255,255,255,0.1);
            border-radius: 16px;
            padding: 40px;
            padding-top: 50px;
            overflow: visible;
        }

        [data-theme="dark"] .blueprint-container {
            background: rgba(23, 19, 14, 0.8);
            border-color: rgba(255,255,255,0.08);
        }

        .blueprint-label {
            position: absolute;
            top: 15px;
            left: 20px;
            font-family: 'Space Mono', monospace;
            font-size: 0.6rem;
            letter-spacing: 0.15em;
            text-transform: uppercase;
            color: var(--tan);
            z-index: 25;
        }

        .blueprint-turntable {
            position: relative;
            width: 100%;
            max-width: 700px;
            margin: 0 auto;
            aspect-ratio: 1.58 / 1;
        }

        .blueprint-turntable svg.tt-diagram {
            width: 100%;
            height: 100%;
        }

        /* Interactive SVG part highlighting */
        .tt-part {
            transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), filter 0.4s ease, opacity 0.3s ease;
            transform-origin: center;
            cursor: pointer;
        }

        .blueprint-turntable.highlighting .tt-part {
            opacity: 0.3;
            filter: saturate(0.3);
        }

        .blueprint-turntable.highlighting .tt-part.active {
            opacity: 1;
            filter: saturate(1) drop-shadow(0 4px 15px rgba(201,111,60,0.5));
            z-index: 10;
        }

        .blueprint-turntable.highlighting .tt-part.active * {
            fill: #c96f3c !important;
            stroke: #e8854a !important;
        }
        /* Keep label text and vinyl grooves readable */
        .blueprint-turntable.highlighting .tt-part.active text {
            fill: #fff !important;
        }
        .blueprint-turntable.highlighting .tt-part.active [fill="none"] {
            fill: none !important;
        }

        /* Dust cover open/close animation */
        .dust-cover-lid {
            transform-origin: 400px 30px;
            transition: transform 0.8s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.4s ease;
        }
        .dust-cover-lid .dc-panel {
            transition: fill 0.5s ease, height 0.5s ease;
        }
        [data-part="dustcover"].active .dust-cover-lid {
            transform: translateY(230px) scaleY(8);
        }
        [data-part="dustcover"].active .dc-panel {
            fill: rgba(180,200,220,0.10);
        }
        [data-part="dustcover"].active .dc-status {
            opacity: 0;
        }
        .dc-status {
            transition: opacity 0.3s ease;
        }

        /* Keep callouts above SVG */
        .callout {
            z-index: 20;
        }

        /* Base outline — hidden (using real photo now) */
        .bp-base, .bp-platter, .bp-tonearm, .bp-tonearm-base {
            display: none;
        }

        /* Callout system */
        .callout {
            position: absolute;
            cursor: pointer;
            transition: all 0.3s;
        }

        .callout-dot {
            width: 16px;
            height: 16px;
            border-radius: 50%;
            background: var(--terracotta);
            border: 3px solid #fff;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2), 0 0 0 2px rgba(201, 111, 60, 0.3);
            position: relative;
            z-index: 22;
            transition: all 0.3s;
        }

        [data-theme="dark"] .callout-dot {
            border-color: #ddd;
        }

        .callout:hover .callout-dot {
            transform: scale(1.3);
            box-shadow: 0 2px 15px rgba(201, 111, 60, 0.5), 0 0 0 4px rgba(201, 111, 60, 0.3);
        }

        .callout-pulse {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            width: 18px;
            height: 18px;
            border-radius: 50%;
            border: 2px solid var(--terracotta);
            animation: calloutPulse 2s ease-out infinite;
            z-index: 1;
        }

        @keyframes calloutPulse {
            0% { width: 18px; height: 18px; opacity: 0.6; }
            100% { width: 45px; height: 45px; opacity: 0; }
        }

        .callout-label {
            position: absolute;
            white-space: nowrap;
            font-family: 'Space Mono', monospace;
            font-size: 0.65rem;
            letter-spacing: 0.08em;
            text-transform: uppercase;
            color: var(--brown);
            background: rgba(255,255,255,0.92);
            backdrop-filter: blur(8px);
            padding: 6px 14px;
            border-radius: 100px;
            border: 1px solid var(--cream-dark);
            box-shadow: 0 4px 15px rgba(0,0,0,0.1);
            opacity: 0;
            transform: translateY(5px);
            transition: all 0.3s;
            pointer-events: none;
            z-index: 25;
        }

        [data-theme="dark"] .callout-label {
            background: rgba(23,19,14,0.92);
            border-color: #2d2418;
            color: #e0d8c8;
        }

        .callout:hover .callout-label {
            opacity: 1;
            transform: translateY(0);
        }

        /* Callout label positions — universal (positions set via inline styles) */
        .callout .callout-label {
            top: -35px;
            left: 50%;
            transform: translateX(-50%) translateY(5px);
        }
        .callout:hover .callout-label {
            transform: translateX(-50%) translateY(0);
        }

        /* ===== PARTS GRID ===== */
        .parts-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
            gap: 24px;
            margin-top: 40px;
        }

        .part-card {
            background: rgba(42, 31, 16, 0.6);
            border: 1px solid rgba(255,255,255,0.1);
            border-radius: 14px;
            padding: 28px;
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
            color: #faf0dc;
        }

        [data-theme="dark"] .part-card {
            background: rgba(42, 31, 16, 0.7);
            border-color: rgba(255,255,255,0.08);
        }

        .part-card {
            cursor: pointer;
        }
        .part-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 40px rgba(0,0,0,0.2);
            border-color: var(--terracotta);
        }

        .part-icon {
            width: 48px;
            height: 48px;
            border-radius: 50%;
            background-size: cover;
            background-position: center;
            margin-bottom: 16px;
            border: 2px solid var(--gold);
            box-shadow: 0 2px 10px rgba(0,0,0,0.2);
        }

        .part-icon svg {
            display: none;
        }

        .part-card h3 {
            font-family: 'Playfair Display', serif;
            font-size: 1.2rem;
            font-weight: 400;
            margin-bottom: 10px;
            color: #fff;
        }

        .part-card p {
            font-size: 0.85rem;
            color: #d4c8b0;
            line-height: 1.7;
        }

        /* ===== PART DETAIL POPUP ===== */
        .part-popup-overlay {
            position: fixed;
            inset: 0;
            background: rgba(0,0,0,0.6);
            backdrop-filter: blur(6px);
            z-index: 9999;
            display: none;
            align-items: center;
            justify-content: center;
            padding: 20px;
            overflow-y: auto;
            overscroll-behavior: contain;
            -webkit-overflow-scrolling: touch;
        }
        .part-popup-overlay.active {
            display: flex;
        }
        .part-popup {
            background: var(--cream);
            border-radius: 20px;
            max-width: 480px;
            width: 100%;
            max-height: 90vh;
            overflow: hidden;
            overflow-y: auto;
            overscroll-behavior: contain;
            -webkit-overflow-scrolling: touch;
            box-shadow: 0 30px 80px rgba(0,0,0,0.3);
            animation: partPopIn 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
            transform: scale(0.9) translateY(20px);
            opacity: 0;
        }
        @keyframes partPopIn {
            to { transform: scale(1) translateY(0); opacity: 1; }
        }
        .part-popup-close {
            position: absolute;
            top: 14px;
            right: 14px;
            width: 36px;
            height: 36px;
            border: none;
            background: rgba(0,0,0,0.08);
            border-radius: 50%;
            cursor: pointer;
            font-size: 1.1rem;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background 0.2s;
            z-index: 2;
            color: var(--brown);
        }
        .part-popup-close:hover {
            background: var(--terracotta);
            color: white;
        }
        .part-popup-illustration {
            position: relative;
            width: 100%;
            display: flex;
            align-items: center;
            justify-content: center;
            overflow: visible;
            background: #2a241c;
            padding: 16px;
        }
        .part-popup-illustration svg {
            width: 100%;
            height: auto;
        }
        .part-popup-illustration img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }
        @keyframes partGlow {
            0%, 100% { opacity: 0.4; }
            50% { opacity: 0.8; }
        }
        .part-glow-ring {
            animation: partGlow 2.5s ease-in-out infinite;
        }
        .part-popup-body {
            padding: 28px 32px 32px;
            overflow-y: auto;
            overscroll-behavior: contain;
            -webkit-overflow-scrolling: touch;
        }
        .part-popup-body .part-popup-icon {
            margin-bottom: 8px;
            display: none;
            align-items: center;
            width: 36px;
            height: 36px;
        }
        .part-popup-body .part-popup-icon svg {
            width: 28px;
            height: 28px;
        }
        .part-popup-body h3 {
            font-family: 'Playfair Display', serif;
            font-size: 1.5rem;
            font-weight: 400;
            margin-bottom: 12px;
            color: var(--brown);
        }
        .part-popup-body p {
            font-size: 0.9rem;
            color: var(--brown-light);
            line-height: 1.8;
            margin-bottom: 12px;
        }
        .part-popup-body .part-tip {
            background: var(--warm-white);
            border-left: 3px solid var(--mustard);
            padding: 12px 16px;
            border-radius: 0 8px 8px 0;
            font-size: 0.8rem;
            color: var(--brown-light);
            margin-top: 16px;
        }
        .part-popup-body .part-tip strong {
            color: var(--terracotta);
        }
        [data-theme="dark"] .part-popup {
            background: #1c170f;
        }
        [data-theme="dark"] .part-popup-close {
            background: rgba(255,255,255,0.1);
            color: var(--cream);
        }
        [data-theme="dark"] .part-popup-body .part-tip {
            background: #231d14;
        }

        @media (max-width: 500px) {
            .part-popup { max-width: 95%; }
            .part-popup-body { padding: 20px 24px 28px; }
        }

        /* ===== RECORD ANATOMY ===== */
        .record-anatomy {
            display: flex;
            align-items: center;
            gap: 60px;
            margin-top: 40px;
        }

        .record-visual {
            flex-shrink: 0;
            width: 320px;
            height: 320px;
            position: relative;
        }

        .record-svg {
            width: 100%;
            height: 100%;
        }

        .record-info {
            flex: 1;
        }

        .record-info h3 {
            font-family: 'Playfair Display', serif;
            font-size: 1.5rem;
            margin-bottom: 20px;
            color: #fff;
        }

        .record-detail {
            display: flex;
            gap: 16px;
            padding: 16px 0;
            border-bottom: 1px solid var(--cream-dark);
            align-items: flex-start;
        }

        [data-theme="dark"] .record-detail {
            border-color: rgba(255,255,255,0.08);
        }

        .record-detail:last-child {
            border-bottom: none;
        }

        .detail-icon {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background-size: cover;
            background-position: center;
            flex-shrink: 0;
            border: 2px solid var(--gold);
            box-shadow: 0 2px 10px rgba(0,0,0,0.2);
        }

        .detail-icon svg {
            display: none;
        }

        .detail-text h4 {
            font-size: 0.85rem;
            font-weight: 600;
            margin-bottom: 4px;
            color: var(--brown);
        }

        .detail-text p {
            font-size: 0.8rem;
            color: var(--brown-light);
            line-height: 1.6;
        }

        /* ===== SIZES TABLE ===== */
        .sizes-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 30px;
            margin-top: 40px;
        }

        .size-card {
            text-align: center;
            padding: 40px 24px;
            background: rgba(42, 31, 16, 0.6);
            border: 1px solid rgba(255,255,255,0.1);
            border-radius: 16px;
            transition: all 0.3s;
            color: var(--cream);
        }

        [data-theme="dark"] .size-card {
            background: rgba(42, 31, 16, 0.7);
            border-color: rgba(255,255,255,0.08);
        }

        .size-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 40px rgba(0,0,0,0.2);
        }

        .size-visual {
            position: relative;
            margin: 0 auto 24px;
        }

        .size-disc {
            width: var(--disc-size);
            height: var(--disc-size);
            border-radius: 50%;
            background:
                radial-gradient(circle, #222 12%, transparent 12.5%),
                radial-gradient(circle, var(--mustard) 12.5%, transparent 13.5%),
                repeating-radial-gradient(circle, transparent, transparent 3px, rgba(60,60,60,0.15) 3px, rgba(60,60,60,0.15) 3.5px),
                radial-gradient(circle, #1a1a1a 0%, #111 50%, #1a1a1a 100%);
            margin: 0 auto;
            box-shadow: 0 4px 20px rgba(0,0,0,0.15);
            transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
        }

        .size-card:hover .size-disc {
            transform: rotate(45deg);
        }

        .size-card h3 {
            font-family: 'Playfair Display', serif;
            font-size: 1.8rem;
            margin-bottom: 6px;
            color: #fff;
        }

        .size-card .size-inches {
            font-family: 'Space Mono', monospace;
            font-size: 0.7rem;
            color: var(--gold-light);
            letter-spacing: 0.1em;
            text-transform: uppercase;
            margin-bottom: 12px;
        }

        .size-card p {
            font-size: 0.82rem;
            color: var(--tan);
            line-height: 1.6;
        }

        .size-specs {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin-top: 16px;
            font-family: 'Space Mono', monospace;
            font-size: 0.65rem;
            color: var(--tan);
        }

        .size-specs span {
            display: flex;
            align-items: center;
            gap: 5px;
        }

        .size-specs span svg {
            display: none;
        }

        /* ===== STEPS / HOW-TO ===== */
        .steps {
            max-width: 700px;
            margin: 40px auto 0;
        }

        .step {
            display: flex;
            gap: 24px;
            padding: 30px;
            border-bottom: none;
            align-items: flex-start;
            background: rgba(42, 31, 16, 0.5);
            border-radius: 14px;
            margin-bottom: 16px;
            border: 1px solid rgba(255,255,255,0.08);
        }

        [data-theme="dark"] .step {
            background: rgba(42, 31, 16, 0.6);
        }

        .step:last-child { border-bottom: none; margin-bottom: 0; }

        .step-number {
            width: 48px;
            height: 48px;
            border-radius: 50%;
            background: var(--rust);
            color: #f7edd8;
            display: flex;
            align-items: center;
            justify-content: center;
            font-family: 'Space Mono', monospace;
            font-size: 0.85rem;
            font-weight: 700;
            flex-shrink: 0;
        }

        .step-content h3 {
            font-family: 'Playfair Display', serif;
            font-size: 1.2rem;
            margin-bottom: 8px;
            color: #fff;
        }

        .step-content p {
            font-size: 0.88rem;
            color: var(--tan);
            line-height: 1.7;
        }

        .step-content .tip {
            margin-top: 10px;
            padding: 10px 16px;
            background: rgba(212, 160, 74, 0.12);
            border-left: 3px solid var(--mustard);
            border-radius: 0 8px 8px 0;
            font-size: 0.8rem;
            color: var(--tan);
        }

        .step-content .tip strong {
            color: var(--mustard);
        }

        /* ===== CARE TIPS ===== */
        .care-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 24px;
            margin-top: 40px;
        }

        .care-card {
            display: flex;
            gap: 18px;
            padding: 24px;
            background: var(--warm-white);
            border: 1px solid var(--cream-dark);
            border-radius: 14px;
            transition: all 0.3s;
            align-items: flex-start;
            color: var(--brown);
        }

        [data-theme="dark"] .care-card {
            background: var(--cream-dark);
            border-color: rgba(255,255,255,0.08);
        }

        .care-card:hover {
            border-color: var(--mustard);
        }

        .care-icon {
            flex-shrink: 0;
            width: 44px;
            height: 44px;
            border-radius: 50%;
            background-size: cover;
            background-position: center;
            border: 2px solid var(--gold);
            box-shadow: 0 2px 10px rgba(0,0,0,0.2);
        }

        .care-icon svg {
            display: none;
        }

        .care-card h4 {
            font-size: 0.9rem;
            font-weight: 600;
            margin-bottom: 6px;
            color: var(--brown);
        }

        .care-card p {
            font-size: 0.82rem;
            color: var(--brown-light);
            line-height: 1.6;
        }

        /* ===== RPM EXPLAINER ===== */
        .rpm-cards {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
            margin-top: 40px;
        }

        .rpm-card {
            text-align: center;
            padding: 36px 24px;
            background: var(--warm-white);
            border: 1px solid var(--cream-dark);
            border-radius: 16px;
            transition: all 0.3s;
            color: var(--brown);
        }

        [data-theme="dark"] .rpm-card {
            background: var(--cream-dark);
            border-color: rgba(255,255,255,0.08);
        }

        .rpm-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 40px rgba(0,0,0,0.2);
        }

        .rpm-number {
            font-family: 'Playfair Display', serif;
            font-size: 3rem;
            color: var(--terracotta);
            line-height: 1;
            margin-bottom: 4px;
        }

        .rpm-unit {
            font-family: 'Space Mono', monospace;
            font-size: 0.65rem;
            letter-spacing: 0.15em;
            text-transform: uppercase;
            color: var(--tan);
            margin-bottom: 16px;
        }

        .rpm-card h3 {
            font-size: 0.95rem;
            font-weight: 600;
            margin-bottom: 8px;
            color: var(--brown);
        }

        .rpm-card p {
            font-size: 0.82rem;
            color: var(--brown-light);
            line-height: 1.6;
        }

        /* ===== GLOSSARY ===== */
        .glossary-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 16px;
            margin-top: 40px;
        }

        .glossary-item {
            padding: 20px 24px;
            background: rgba(42, 31, 16, 0.6);
            border: 1px solid rgba(255,255,255,0.1);
            border-radius: 12px;
            transition: all 0.3s;
        }

        [data-theme="dark"] .glossary-item {
            background: rgba(42, 31, 16, 0.7);
            border-color: rgba(255,255,255,0.08);
        }

        .glossary-item:hover {
            border-color: var(--terracotta);
        }

        .glossary-item dt {
            font-weight: 600;
            font-size: 0.9rem;
            margin-bottom: 6px;
            color: var(--gold-light);
        }

        .glossary-item dd {
            font-size: 0.82rem;
            color: var(--tan);
            line-height: 1.6;
        }

        /* ===== CTA ===== */
        .v101-cta {
            text-align: center;
            padding: 80px 50px;
            background: var(--brown);
            color: var(--cream);
        }

        [data-theme="dark"] .v101-cta {
            background: #15120d;
        }

        .v101-cta h2 {
            font-family: 'Playfair Display', serif;
            font-size: clamp(1.8rem, 4vw, 2.5rem);
            margin-bottom: 15px;
        }

        .v101-cta p {
            color: var(--tan);
            margin-bottom: 30px;
            font-size: 0.95rem;
        }

        .btn {
            display: inline-flex;
            align-items: center;
            gap: 10px;
            padding: 16px 28px;
            font-family: inherit;
            font-size: 0.75rem;
            font-weight: 600;
            letter-spacing: 0.1em;
            text-transform: uppercase;
            text-decoration: none;
            border-radius: 100px;
            cursor: pointer;
            transition: all 0.3s;
            border: none;
        }

        .btn-primary {
            background: var(--terracotta);
            color: white;
        }

        .btn-primary:hover {
            background: var(--mustard);
            color: var(--brown);
            transform: translateY(-2px);
            box-shadow: 0 8px 24px rgba(212, 160, 74, 0.3);
        }

        .btn-secondary {
            background: transparent;
            color: var(--cream);
            border: 1px solid rgba(255,255,255,0.2);
        }

        .btn-secondary:hover {
            border-color: var(--mustard);
            color: var(--mustard);
        }

        /* ===== FOOTER ===== */
        footer {
            background: var(--brown);
            color: var(--cream);
            padding: 40px 50px 25px;
            text-align: center;
            transition: background 0.3s;
        }

        [data-theme="dark"] footer {
            background: #12100c;
        }

        footer p {
            font-size: 0.75rem;
            color: var(--tan);
        }

        footer a {
            color: var(--tan);
            text-decoration: underline;
        }

        /* ===== RESPONSIVE ===== */
        @media (max-width: 900px) {
            .v101-hero { padding: 60px 20px 40px; }
            .v101-section { padding: 60px 20px; }
            .toc { padding: 0 20px 40px; }
            .toc.sticky { padding: 8px 12px; gap: 6px; }
            .toc.sticky a { padding: 5px 10px; font-size: 0.55rem; }
            .blueprint-container { padding: 40px 20px; margin: 0 20px 40px; }
            .record-anatomy { flex-direction: column; }
            .record-visual { width: 240px; height: 240px; }
            .sizes-grid { grid-template-columns: 1fr; }
            .rpm-cards { grid-template-columns: 1fr; }
            .care-grid { grid-template-columns: 1fr; }
            .parts-grid { grid-template-columns: 1fr; }
            footer { padding: 30px 20px 70px; }
        }

        @media (max-width: 600px) {
            .v101-hero h1 { font-size: 2.2rem; }
            .glossary-grid { grid-template-columns: 1fr; }
        }

        @media (max-width: 480px) {
            .v101-hero { padding: 50px 15px 30px; }
            .v101-section { padding: 40px 15px; }
            .toc { padding: 0 15px 30px; }
            .blueprint-container { padding: 30px 15px; margin: 0 10px 30px; }
            .record-visual { width: 180px; height: 180px; }
            footer { padding: 30px 15px 70px; }
        }
        .cart-panel-backdrop { position: fixed; inset: 0; background: rgba(0,0,0,0.4); z-index: 9998; opacity: 0; pointer-events: none; transition: opacity 0.3s; }
        .cart-panel-backdrop.open { opacity: 1; pointer-events: auto; }
        .cart-panel { position: fixed; top: 0; right: 0; bottom: 0; width: 420px; max-width: 100vw; background: var(--cream); box-shadow: -10px 0 40px rgba(0,0,0,0.2); z-index: 9999; transform: translateX(100%); transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1); display: flex; flex-direction: column; overflow: hidden; }
        [data-theme="dark"] .cart-panel { background: #1a1a1a; }
        .cart-panel.open { transform: translateX(0); }
        .cart-panel-header { padding: 22px 25px; border-bottom: 1px solid var(--cream-dark); display: flex; justify-content: space-between; align-items: center; }
        .cart-panel-header h3 { font-family: 'Playfair Display', serif; font-size: 1.3rem; }
        .cart-panel-close { background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--brown); transition: color 0.2s; }
        .cart-panel-close:hover { color: var(--rust); }
        .cart-items-container { flex: 1; overflow-y: auto; padding: 0; }
        .cart-item { display: flex; align-items: center; gap: 14px; padding: 16px 25px; border-bottom: 1px solid var(--cream-dark); transition: background 0.2s; }
        .cart-item:hover { background: rgba(0,0,0,0.02); }
        [data-theme="dark"] .cart-item:hover { background: rgba(255,255,255,0.03); }
        .cart-item-art { width: 60px; height: 60px; border-radius: 8px; overflow: hidden; flex-shrink: 0; background: var(--cream-dark); }
        .cart-item-art img { width: 100%; height: 100%; object-fit: cover; }
        .cart-item-placeholder { width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; color: var(--tan); }
        .cart-item-info { flex: 1; min-width: 0; }
        .cart-item-title { font-family: 'Playfair Display', serif; font-size: 0.85rem; font-weight: 600; margin-bottom: 2px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
        .cart-item-artist { font-size: 0.75rem; color: var(--tan); margin-bottom: 3px; }
        .cart-item-meta { font-family: 'Space Mono', monospace; font-size: 0.65rem; }
        .cart-item-controls { display: flex; flex-direction: column; align-items: flex-end; gap: 6px; }
        .cart-qty-controls { display: flex; align-items: center; gap: 8px; border: 1px solid var(--cream-dark); border-radius: 100px; padding: 2px 4px; }
        .cart-qty-controls button { width: 24px; height: 24px; background: none; border: none; cursor: pointer; font-size: 1rem; color: var(--brown); display: flex; align-items: center; justify-content: center; border-radius: 50%; transition: background 0.2s; }
        .cart-qty-controls button:hover { background: var(--cream-dark); }
        .cart-qty-controls span { font-family: 'Space Mono', monospace; font-size: 0.75rem; min-width: 16px; text-align: center; }
        .cart-item-subtotal { font-family: 'Space Mono', monospace; font-size: 0.8rem; font-weight: 700; color: var(--terracotta); }
        .cart-item-remove { background: none; border: none; cursor: pointer; font-size: 0.7rem; color: var(--tan); transition: color 0.2s; padding: 2px; }
        .cart-item-remove:hover { color: var(--rust); }
        .cart-footer { padding: 20px 25px; border-top: 2px solid var(--cream-dark); background: var(--warm-white); }
        [data-theme="dark"] .cart-footer { background: #222; }
        .cart-total-row { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; }
        .cart-total-label { font-family: 'Space Mono', monospace; font-size: 0.7rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--tan); }
        .cart-total-amount { font-family: 'Playfair Display', serif; font-size: 1.5rem; font-weight: 700; color: var(--terracotta); }
        .cart-checkout-btn { display: block; width: 100%; padding: 16px; background: linear-gradient(135deg, var(--terracotta), var(--rust)); color: white; border: none; border-radius: 100px; font-family: 'Space Mono', monospace; font-size: 0.8rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; cursor: pointer; transition: all 0.3s; text-align: center; text-decoration: none; }
        .cart-checkout-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(181, 50, 42, 0.3); }
        .cart-continue-btn { display: block; width: 100%; padding: 12px; background: none; border: 1px solid var(--cream-dark); border-radius: 100px; font-family: 'Space Mono', monospace; font-size: 0.7rem; letter-spacing: 0.08em; text-transform: uppercase; cursor: pointer; color: var(--brown); margin-top: 10px; transition: all 0.2s; text-align: center; }
        .cart-continue-btn:hover { border-color: var(--terracotta); color: var(--terracotta); }