/* ==================== Design Tokens ==================== */
        :root {
            --color-bg-primary: #ffffff;
            --color-bg-secondary: #fafafa;
            --color-bg-tertiary: #f5f5f5;
            --color-text-primary: #0a0a0a;
            --color-text-secondary: #666666;
            --color-text-tertiary: #999999;
            --color-accent: #0a0a0a;
            --color-border: #e5e5e5;
            --color-border-strong: #d0d0d0;
            
            --font-family-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
            --font-family-mono: 'SF Mono', Monaco, 'Cascadia Code', monospace;
            
            --font-size-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
            --font-size-sm: clamp(0.875rem, 0.8rem + 0.375vw, 1rem);
            --font-size-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
            --font-size-lg: clamp(1.125rem, 1rem + 0.625vw, 1.5rem);
            --font-size-xl: clamp(1.5rem, 1.25rem + 1.25vw, 2.25rem);
            --font-size-2xl: clamp(2rem, 1.5rem + 2.5vw, 3.5rem);
            --font-size-3xl: clamp(2.5rem, 2rem + 2.5vw, 4.5rem);
            
            --space-xs: clamp(0.5rem, 0.4rem + 0.5vw, 0.75rem);
            --space-sm: clamp(1rem, 0.9rem + 0.5vw, 1.5rem);
            --space-md: clamp(1.5rem, 1.3rem + 1vw, 2.5rem);
            --space-lg: clamp(2rem, 1.7rem + 1.5vw, 3.5rem);
            --space-xl: clamp(3rem, 2.5rem + 2.5vw, 5rem);
            --space-2xl: clamp(4rem, 3rem + 5vw, 7rem);
            
            --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
            --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
            --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
        }
        
        /* ==================== Reset & Base ==================== */
        *, *::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-family-primary);
            font-size: var(--font-size-base);
            line-height: 1.6;
            color: var(--color-text-primary);
            background-color: var(--color-bg-primary);
            min-height: 100vh;
            position: relative;
        }
        
        /* ==================== Typography ==================== */
        h1, h2, h3 {
            line-height: 1.2;
            font-weight: 300;
            letter-spacing: -0.02em;
        }
        
        h1 { font-size: var(--font-size-3xl); }
        h2 { font-size: var(--font-size-2xl); font-weight: 400; }
        h3 { font-size: var(--font-size-xl); font-weight: 400; }
        
        /* Typing Animation */
        .typing-text {
            display: inline;
        }
        
        .typing-text::after {
            content: '|';
            display: inline-block;
            margin-left: 2px;
            animation: blink 1s step-end infinite;
        }
        
        .typing-text.completed::after {
            display: none;
        }
        
        @keyframes blink {
            50% { opacity: 0; }
        }
        
        /* ==================== Skip Link ==================== */
        .skip-link {
            position: absolute;
            top: -100px;
            left: 0;
            background: var(--color-accent);
            color: var(--color-bg-primary);
            padding: var(--space-sm);
            z-index: 1000;
            font-weight: 500;
        }
        
        .skip-link:focus {
            top: 0;
        }
        
        /* ==================== Header ==================== */
        .site-header {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 100;
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border-bottom: 1px solid var(--color-border);
        }
        
        .nav-container {
            max-width: 1200px;
            margin: 0 auto;
            padding: var(--space-sm) var(--space-md);
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .logo {
            font-size: var(--font-size-lg);
            font-weight: 300;
            color: var(--color-text-primary);
            text-decoration: none;
            line-height: 1.1;
        }
        
        .nav-menu {
            display: flex;
            gap: var(--space-md);
            list-style: none;
        }
        
        .nav-link {
            font-size: var(--font-size-sm);
            font-weight: 400;
            color: var(--color-text-secondary);
            transition: color var(--transition-base);
            text-decoration: none;
            position: relative;
        }
        
        .nav-link::after {
            content: '';
            position: absolute;
            bottom: -4px;
            left: 0;
            width: 0;
            height: 1px;
            background: var(--color-accent);
            transition: width var(--transition-base);
        }
        
        .nav-link:hover::after,
        .nav-link:focus::after {
            width: 100%;
        }
        
        /* ==================== Hero ==================== */
        .hero {
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            text-align: center;
            padding: var(--space-2xl) var(--space-md);
            padding-top: calc(var(--space-2xl) + 60px);
        }
        
        .hero-content {
            max-width: 800px;
        }
        
        .hero-title {
            margin-bottom: var(--space-md);
            font-weight: 300;
            letter-spacing: -0.03em;
        }
        
        .hero-subtitle {
            font-size: var(--font-size-lg);
            color: var(--color-text-secondary);
            margin-bottom: var(--space-lg);
            font-weight: 300;
        }
        
        .hero-description {
            font-size: var(--font-size-base);
            color: var(--color-text-secondary);
            line-height: 1.8;
            min-height: 3em;
        }
        
        /* ==================== Section ==================== */
        .section {
            min-height: 100vh;
            padding: var(--space-2xl) var(--space-md);
            border-top: 1px solid var(--color-border);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            touch-action: pan-y;
        }
        
        .section:nth-child(even) {
            background: var(--color-bg-secondary);
        }
        
        .section-container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
        }
        
        .section-header {
            margin-bottom: var(--space-xl);
            text-align: center;
        }
        
        .section-number {
            display: block;
            font-size: var(--font-size-xs);
            font-family: var(--font-family-mono);
            color: var(--color-text-tertiary);
            margin-bottom: var(--space-xs);
        }
        
        .section-title {
            margin-bottom: var(--space-sm);
        }
        
        .section-description {
            font-size: var(--font-size-base);
            color: var(--color-text-secondary);
            line-height: 1.7;
            max-width: 800px;
            margin: 0 auto;
            min-height: 2em;
        }
        
        /* ==================== Machine Canvas ==================== */
        .machine-canvas-wrapper {
            position: relative;
            width: 100%;
            height: 70vh;
            max-height: 600px;
            border: 1px solid var(--color-border);
            border-radius: 4px;
            overflow: hidden;
            background: var(--color-bg-tertiary);
            margin-bottom: var(--space-lg);
        }
        
        #imageCanvas-container,
        #soundCanvas-container {
            width: 100%;
            height: 100%;
            display: flex;
            align-items: center;
            justify-content: center;
            touch-action: none;
        }
        
        #imageCanvas-container canvas,
        #soundCanvas-container canvas {
            touch-action: none;
        }
        
        .canvas-prompt {
            position: absolute;
            left: 50%;
            top: 50%;
            transform: translate(-50%, -50%);
            font-size: var(--font-size-lg);
            font-weight: 200;
            letter-spacing: 0.2em;
            color: var(--color-text-tertiary);
            opacity: 0.7;
            pointer-events: none;
            transition: opacity 1s ease;
        }
        
        .canvas-prompt.hidden {
            opacity: 0;
        }
        
        /* ==================== Controls ==================== */
        .machine-controls {
            display: grid;
            gap: var(--space-md);
            padding: var(--space-lg);
            border: 1px solid var(--color-border);
            border-radius: 4px;
            background: var(--color-bg-primary);
        }
        
        .control-group {
            display: flex;
            flex-direction: column;
            gap: var(--space-xs);
        }
        
        .control-label {
            font-size: var(--font-size-sm);
            color: var(--color-text-secondary);
            font-weight: 400;
        }
        
        input[type="file"] {
            font-size: var(--font-size-sm);
            padding: var(--space-sm);
            border: 1px solid var(--color-border);
            border-radius: 4px;
            background: var(--color-bg-primary);
            transition: border-color var(--transition-base);
        }
        
        input[type="file"]:hover {
            border-color: var(--color-border-strong);
        }
        
        input[type="range"] {
            width: 100%;
            height: 2px;
            background: var(--color-border);
            outline: none;
            -webkit-appearance: none;
        }
        
        input[type="range"]::-webkit-slider-thumb {
            -webkit-appearance: none;
            width: 16px;
            height: 16px;
            background: var(--color-accent);
            cursor: pointer;
            border-radius: 50%;
            transition: transform var(--transition-fast);
        }
        
        input[type="range"]::-webkit-slider-thumb:hover {
            transform: scale(1.2);
        }
        
        input[type="range"]::-moz-range-thumb {
            width: 16px;
            height: 16px;
            background: var(--color-accent);
            cursor: pointer;
            border-radius: 50%;
            border: none;
            transition: transform var(--transition-fast);
        }
        
        select {
            padding: var(--space-sm);
            border: 1px solid var(--color-border);
            border-radius: 4px;
            background: var(--color-bg-primary);
            font-size: var(--font-size-sm);
            transition: border-color var(--transition-base);
        }
        
        .btn {
            padding: var(--space-sm) var(--space-md);
            border: 1px solid var(--color-accent);
            background: var(--color-bg-primary);
            color: var(--color-text-primary);
            font-size: var(--font-size-sm);
            font-weight: 400;
            border-radius: 4px;
            transition: all var(--transition-base);
        }
        
        .btn:hover:not(:disabled) {
            background: var(--color-accent);
            color: var(--color-bg-primary);
        }
        
        .btn:disabled {
            opacity: 0.4;
            cursor: not-allowed;
        }
        
        .btn-primary {
            background: var(--color-accent);
            color: var(--color-bg-primary);
        }
        
        .btn-primary:hover:not(:disabled) {
            background: var(--color-text-primary);
        }
        
        .btn-group {
            display: flex;
            gap: var(--space-sm);
            flex-wrap: wrap;
        }
        
        /* ==================== Sound Machine Specific ==================== */
        .sound-controls {
            display: grid;
            gap: var(--space-md);
        }
        
        .audio-player {
            display: flex;
            flex-direction: column;
            gap: var(--space-md);
            padding: var(--space-md);
            border: 1px solid var(--color-border);
            border-radius: 4px;
            background: var(--color-bg-secondary);
            width: 100%;
        }
        
        .audio-player-controls {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: var(--space-sm);
            flex-wrap: wrap;
        }
        
        .audio-player-controls .btn {
            min-width: 80px;
            flex-shrink: 0;
        }
        
        .audio-player-timeline {
            display: flex;
            align-items: center;
            gap: var(--space-sm);
            width: 100%;
        }
        
        .audio-player-frequency {
            display: flex;
            justify-content: center;
            padding-top: var(--space-md);
            border-top: 1px solid var(--color-border);
        }
        
        .time-display {
            font-size: var(--font-size-xs);
            font-family: var(--font-family-mono);
            color: var(--color-text-secondary);
            min-width: 45px;
        }
        
        .seek-bar {
            flex: 1;
            height: 4px;
            background: var(--color-border);
            border-radius: 2px;
            position: relative;
            cursor: pointer;
        }
        
        .seek-bar-progress {
            height: 100%;
            background: var(--color-accent);
            border-radius: 2px;
            transition: width 100ms linear;
        }
        
        .freq-display {
            display: flex;
            gap: var(--space-md);
            justify-content: center;
            align-items: flex-end;
        }
        
        .freq-bar-container {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: var(--space-xs);
            min-width: 40px;
        }
        
        .freq-bars {
            display: flex;
            flex-direction: column-reverse;
            gap: 2px;
            height: 60px;
        }
        
        .freq-bar {
            width: 20px;
            height: 4px;
            background: var(--color-border);
            border-radius: 2px;
            transition: all 75ms ease;
        }
        
        .freq-bar.active {
            background: var(--color-accent);
        }
        
        .freq-label {
            font-size: var(--font-size-xs);
            color: var(--color-text-tertiary);
            text-transform: uppercase;
            font-family: var(--font-family-mono);
        }
        
        .settings-panel {
            position: absolute;
            top: calc(var(--space-sm) + 50px);
            right: var(--space-sm);
            width: 280px;
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border: 1px solid var(--color-border);
            border-radius: 4px;
            padding: var(--space-md);
            z-index: 90;
            display: none;
            max-height: calc(100% - var(--space-sm) - 60px);
            overflow-y: auto;
        }
        
        .settings-panel.open {
            display: block;
        }
        
        .settings-btn {
            position: absolute;
            top: var(--space-sm);
            right: var(--space-sm);
            width: 40px;
            height: 40px;
            border: 1px solid var(--color-border);
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            border-radius: 4px;
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 91;
            transition: all var(--transition-base);
        }
        
        .settings-btn:hover {
            background: var(--color-bg-secondary);
        }
        
        /* ==================== Store ==================== */
        .store-card {
            text-align: center;
            padding: var(--space-xl);
            border: 1px solid var(--color-border);
            border-radius: 4px;
            max-width: 600px;
            margin: 0 auto;
        }
        
        .store-icon {
            width: 60px;
            height: 60px;
            margin: 0 auto var(--space-md);
            border: 2px solid var(--color-accent);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        
        .store-icon svg {
            width: 30px;
            height: 30px;
        }
        
        /* ==================== Footer ==================== */
        .site-footer {
            border-top: 1px solid var(--color-border);
            padding: var(--space-xl) var(--space-md);
            background: var(--color-bg-secondary);
            text-align: center;
        }
        
        .footer-content {
            color: var(--color-text-secondary);
            font-size: var(--font-size-sm);
        }
        
        /* ==================== Responsive ==================== */
        @media (max-width: 768px) {
            .nav-menu {
                gap: var(--space-sm);
            }
            
            .nav-link {
                font-size: var(--font-size-xs);
            }
            
            .btn-group {
                flex-direction: column;
            }
            
            .btn-group .btn {
                width: 100%;
            }
            
            .settings-panel {
                right: var(--space-sm);
                width: calc(100% - var(--space-md));
            }
            
            .settings-btn {
                right: var(--space-sm);
            }
        }
        
        /* ==================== Accessibility ==================== */
        @media (prefers-reduced-motion: reduce) {
            *, *::before, *::after {
                animation-duration: 0.01ms !important;
                animation-iteration-count: 1 !important;
                transition-duration: 0.01ms !important;
            }
            
            html {
                scroll-behavior: auto;
            }
        }
        
        :focus-visible {
            outline: 2px solid var(--color-accent);
            outline-offset: 2px;
        }
        
        .visually-hidden {
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            white-space: nowrap;
            border-width: 0;
        }