/* ── Reset & Base ── */
        *, *::before, *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        :root {
            --black:       #0b0b0b;
            --white:       #f7f7f5;
            --grey-dark:   #181818;
            --grey-rule:   #d0d0cc;
            --grey-pale:   #eeeeec;
            /*
             * AAA-compliant muted text colours (WCAG 1.4.6, 7:1 minimum):
             *   --text-dark  #a8a8a8  →  8.55:1 on #0b0b0b  |  7.48:1 on #181818
             *   --text-light #4d4d4d  →  7.88:1 on #f7f7f5  |  7.29:1 on #eeeeec
             */
            --text-dark:   #a8a8a8;
            --text-light:  #4d4d4d;
            /* AAA-compliant form border (SC 1.4.11, 3:1 non-text minimum):
             *   #6e6e6e  →  3.98:1 on #0b0b0b
             */
            --border-dark: #6e6e6e;
            --nav-bg:     rgba(11, 11, 11, 0.94);
            --hero-mid:   #1e1e1e;
            /*
             * --fg is the foreground/accent colour that opposes --black:
             *   dark themes  → #f7f7f5 (white)  keeps existing behaviour
             *   light theme  → #0b0b0b (black)   inverts dark-section text
             */
            --fg:         #f7f7f5;
            --hero-fade:  rgba(247, 247, 245, 0.2); /* hero rule; inverted in light theme */
            /*
             * --ink is the permanent body/heading text colour for light-background
             * sections (Mission, Scale, Pillars). Unlike --black, it never changes
             * between themes so those sections always stay dark-on-light.
             */
            --ink:        #0b0b0b;
        }

        html {
            font-size: 16px;
            scroll-behavior: smooth;
        }

        body {
            background: var(--white);
            color: var(--ink);
            font-family: 'Outfit', sans-serif;
            font-weight: 300;
            line-height: 1.65;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        h1, h2, h3, h4 {
            font-family: 'Crimson Pro', serif;
            font-weight: 400;
            line-height: 1.1;
        }

        /* ── Focus (SC 2.4.13 AAA — 3:1 contrast, enclosed area) ── */
        :focus-visible {
            outline: 2px solid var(--fg);
            outline-offset: 3px;
            border-radius: 1px;
        }

        /* ── Navigation ── */
        /*
         * Persistent dark background ensures nav text maintains AAA contrast
         * across all scroll positions, regardless of underlying section colour.
         */
        nav {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 200;
            display: flex;
            flex-direction: column;
            background: var(--nav-bg);
            backdrop-filter: blur(14px);
            -webkit-backdrop-filter: blur(14px);
            border-bottom: 1px solid rgba(247, 247, 245, 0.07);
        }

        .nav-inner {
            padding: 1.4rem 3.5rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .nav-logo {
            font-family: 'Crimson Pro', serif;
            font-size: 1.25rem;
            font-weight: 300;
            color: var(--fg);
            text-decoration: none;
            letter-spacing: 0.015em;
        }

        /* Medium Italic for };{ in all horizontal logo instances */
        .logo-glyph {
            font-weight: 500;
            font-style: italic;
        }

        .nav-links {
            display: flex;
            gap: 0.25rem;
            list-style: none;
        }

        /* Padding extends the click/tap target (SC 2.5.5 AAA: 44×44px minimum) */
        .nav-links a {
            display: inline-block;
            font-family: 'Outfit', sans-serif;
            font-weight: 300;
            font-size: 0.72rem;
            color: var(--text-dark);  /* #a8a8a8 → 8.55:1 on nav dark bg */
            text-decoration: none;
            letter-spacing: 0.18em;
            text-transform: uppercase;
            transition: color 0.25s;
            padding: 0.85rem 1rem;    /* ≥44px tall touch target */
        }

        .nav-links a:hover {
            color: var(--fg);
        }

        /* ── Color Theme Bar ── */
        .color-bar {
            display: flex;
            width: 100%;
            height: 10px;
            flex-shrink: 0;
        }

        .color-swatch {
            flex: 1;
            border: none;
            cursor: pointer;
            padding: 0;
            transition: filter 0.18s;
        }

        .color-swatch:hover {
            filter: brightness(1.25);
        }

        /* Inset bottom highlight marks the active swatch */
        .color-swatch[aria-pressed="true"] {
            box-shadow: inset 0 -2px 0 rgba(255, 255, 255, 0.8);
            filter: brightness(1.15);
        }

        .color-swatch:focus-visible {
            outline: 2px solid #ffffff;
            outline-offset: -2px;
            z-index: 1;
            position: relative;
        }

        /* White swatch needs a dark active indicator (white-on-white is invisible) */
        .color-swatch[data-light][aria-pressed="true"] {
            box-shadow: inset 0 -2px 0 rgba(0, 0, 0, 0.55);
        }

        /* ── Hero ── */
        .hero {
            min-height: 100svh;
            background: var(--black);
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            text-align: center;
            padding: 8rem 2rem 6rem;
            position: relative;
        }

        .hero::before {
            content: '';
            position: absolute;
            inset: 0;
            background: radial-gradient(ellipse 70% 60% at 50% 40%, var(--hero-mid) 0%, var(--black) 100%);
            pointer-events: none;
        }

        .hero-inner {
            position: relative;
            z-index: 1;
        }

        .hero-eyebrow {
            font-family: 'Outfit', sans-serif;
            font-weight: 300;
            font-size: 0.7rem;
            letter-spacing: 0.28em;
            text-transform: uppercase;
            color: var(--text-dark);  /* #a8a8a8 → 8.55:1 on #0b0b0b */
            margin-bottom: 2.5rem;
        }

        .hero-logo {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 0;
            margin-bottom: 2.25rem;
            line-height: 1;
        }

        .hero-logo-glyph {
            font-family: 'Crimson Pro', serif;
            font-weight: 500;
            font-style: italic;
            font-size: clamp(7rem, 18vw, 16rem);
            color: var(--fg);
            line-height: 0.9;
            display: block;
        }

        .hero-logo-text {
            font-family: 'Crimson Pro', serif;
            font-weight: 200;
            font-style: normal;
            font-size: clamp(3.5rem, 9vw, 8rem);
            color: var(--fg);
            letter-spacing: -0.015em;
            display: block;
        }

        .hero-logo-bullet {
            font-size: 0.45em;
            vertical-align: middle;
            position: relative;
            bottom: 0.08em;
        }

        .hero-rule {
            width: 1px;
            height: 48px;
            background: var(--hero-fade);
            margin: 0 auto 2.25rem;
        }

        .hero-tagline {
            font-family: 'Outfit', sans-serif;
            font-weight: 300;
            font-size: clamp(0.9rem, 1.4vw, 1.05rem);
            color: var(--text-dark);  /* #a8a8a8 → 8.55:1 on #0b0b0b */
            letter-spacing: 0.06em;
            max-width: 520px;
            line-height: 1.9;
        }

        .hero-scroll {
            position: absolute;
            bottom: 2.75rem;
            left: 50%;
            transform: translateX(-50%);
            font-family: 'Outfit', sans-serif;
            font-weight: 300;
            font-size: 0.65rem;
            color: var(--text-dark);  /* #a8a8a8 → 8.55:1 on #0b0b0b */
            letter-spacing: 0.22em;
            text-transform: uppercase;
            white-space: nowrap;
        }

        /* ── Shared Section Utilities ── */
        section {
            padding: 7.5rem 2rem;
        }

        .container {
            max-width: 1000px;
            margin: 0 auto;
        }

        .container-narrow {
            max-width: 640px;
            margin: 0 auto;
        }

        .section-rule {
            width: 36px;
            height: 1px;
            background: var(--grey-rule);
            margin: 0 auto 3.5rem;
        }

        .section-rule--light {
            background: rgba(247, 247, 245, 0.2);
        }

        /* ── Mission ── */
        .mission {
            background: var(--white);
            text-align: center;
        }

        .mission h2 {
            font-size: clamp(2.2rem, 4.5vw, 3.75rem);
            margin-bottom: 2rem;
        }

        .mission p {
            font-size: 1.05rem;
            color: var(--text-light);  /* #4d4d4d → 7.88:1 on #f7f7f5 */
            line-height: 1.9;
            max-width: 580px;
            margin: 0 auto 1.4rem;
        }

        /* ── Scale ── */
        .scale {
            background: var(--grey-pale);
            text-align: center;
        }

        .scale h2 {
            font-size: clamp(2rem, 3.5vw, 3.2rem);
            margin-bottom: 0.75rem;
        }

        .scale .intro {
            font-size: 0.95rem;
            color: var(--text-light);  /* #4d4d4d → 7.29:1 on #eeeeec */
            letter-spacing: 0.04em;
            margin-bottom: 1.8rem;
        }

        .scale .intro:last-of-type {
            margin-bottom: 4rem;
        }

        .scale-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            border: 1px solid var(--grey-rule);
        }

        .scale-item {
            padding: 3rem 1.5rem;
            border-right: 1px solid var(--grey-rule);
        }

        .scale-item:last-child {
            border-right: none;
        }

        .scale-unit {
            font-family: 'Crimson Pro', serif;
            font-size: 1.9rem;
            color: var(--ink);
            margin-bottom: 0.5rem;
        }

        .scale-sublabel {
            font-size: 0.7rem;
            letter-spacing: 0.16em;
            text-transform: uppercase;
            color: var(--text-light);  /* #4d4d4d → 7.29:1 on #eeeeec */
        }

        /* ── Pillars ── */
        .pillars {
            background: var(--white);
        }

        .pillars-header {
            text-align: center;
            margin-bottom: 5rem;
        }

        .pillars-header h2 {
            font-size: clamp(2rem, 3.5vw, 3.2rem);
            margin-bottom: 0.75rem;
        }

        .pillars-header .intro {
            font-size: 0.95rem;
            color: var(--text-light);  /* #4d4d4d → 7.88:1 on #f7f7f5 */
            letter-spacing: 0.04em;
            margin-bottom: 1.8rem;
        }

        .pillars-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 3.5rem;
        }

        .pillar {
            border-top: 1px solid var(--grey-rule);
            padding-top: 2rem;
        }

        .pillar-num {
            font-family: 'Crimson Pro', serif;
            font-size: 0.8rem;
            color: var(--text-light);  /* #4d4d4d → 7.88:1 on #f7f7f5 */
            letter-spacing: 0.1em;
            margin-bottom: 1.25rem;
        }

        .pillar h3 {
            font-size: 1.7rem;
            margin-bottom: 1rem;
        }

        .pillar p {
            font-size: 0.92rem;
            color: var(--text-light);  /* #4d4d4d → 7.88:1 on #f7f7f5 */
            line-height: 1.85;
        }

        /* ── About ── */
        .about {
            background: var(--grey-dark);
            text-align: center;
        }

        .about h2 {
            font-size: clamp(2rem, 3.5vw, 3.2rem);
            color: var(--fg);
            margin-bottom: 0.75rem;
        }

        .about p {
            font-size: 0.95rem;
            color: var(--text-dark);  /* #a8a8a8 → 7.48:1 on #181818 */
            line-height: 1.9;
            letter-spacing: 0.04em;
            margin: 0 auto 1.8rem;
        }

        .about .section-rule {
            background: rgba(247, 247, 245, 0.18);
        }

        /* ── CTA ── */
        .cta {
            background: var(--black);
            text-align: center;
        }

        .cta h2 {
            font-size: clamp(2.2rem, 4vw, 3.75rem);
            color: var(--fg);
            margin-bottom: 1.25rem;
        }

        .cta p {
            font-size: 0.95rem;
            color: var(--text-dark);  /* #a8a8a8 → 8.55:1 on #0b0b0b */
            line-height: 1.9;
            max-width: 480px;
            margin: 0 auto 3rem;
        }

        .substack-btn {
            display: inline-block;
            background: var(--fg);
            color: var(--black);
            padding: 1rem 2.25rem;
            min-height: 44px;
            font-family: 'Outfit', sans-serif;
            font-weight: 400;
            font-size: 0.68rem;
            letter-spacing: 0.18em;
            text-transform: uppercase;
            text-decoration: none;
            transition: filter 0.2s;
            white-space: nowrap;
        }

        .substack-btn:hover {
            filter: brightness(0.88);
        }

        /* ── Footer ── */
        footer {
            background: var(--grey-dark);
            border-top: 1px solid rgba(247, 247, 245, 0.07);
            padding: 2.5rem 3.5rem;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        /*
         * Logotype text is exempt from SC 1.4.6 contrast requirements
         * (WCAG exception for logos and brand names). Colour set to
         * --text-dark for visual quality regardless.
         */
        .footer-logo {
            font-family: 'Crimson Pro', serif;
            font-size: 1.05rem;
            font-weight: 300;
            color: var(--text-dark);
        }

        .footer-copy {
            font-size: 0.7rem;
            color: var(--text-dark);  /* #a8a8a8 → 7.48:1 on #181818 */
            letter-spacing: 0.12em;
        }

        /* ── Hamburger menu toggle ── */
        body.menu-open {
            overflow: hidden;
        }

        /*
         * ── Mobile Menu Overlay ──
         * The nav uses backdrop-filter which creates a containing block for
         * position:fixed descendants in Safari and Chrome — any fixed child
         * is clipped to the nav's own bounding box instead of the viewport.
         * Moving the overlay outside <nav> avoids this entirely.
         * z-index: 190 keeps it below the nav bar (200) so the logo and
         * hamburger remain visible and tappable at all times.
         */
        .mobile-menu {
            display: none; /* hidden on desktop */
        }

        @media (max-width: 768px) {
            .mobile-menu {
                display: flex;
                position: fixed;
                inset: 0;
                z-index: 190;
                background: var(--black);
                flex-direction: column;
                justify-content: center;
                align-items: center;
                overflow: hidden;
                /* Hidden state */
                visibility: hidden;
                opacity: 0;
                pointer-events: none;
                transform: translateY(-8px);
                transition: opacity 0.3s ease, transform 0.35s ease,
                            visibility 0s linear 0.35s;
            }

            .mobile-menu.is-open {
                visibility: visible;
                opacity: 1;
                pointer-events: auto;
                transform: translateY(0);
                transition: opacity 0.3s ease, transform 0.35s ease;
            }

            /* Decorative };{ watermark */
            .mobile-menu::before {
                content: '};{';
                font-family: 'Crimson Pro', Georgia, serif;
                font-weight: 500;
                font-style: italic;
                font-size: 50vw;
                color: rgba(247, 247, 245, 0.04);
                position: absolute;
                top: 50%;
                left: 50%;
                transform: translate(-50%, -50%);
                pointer-events: none;
                user-select: none;
                white-space: nowrap;
            }

            .mobile-menu ul {
                list-style: none;
                text-align: center;
                position: relative;
                z-index: 1;
            }

            .mobile-menu a {
                display: block;
                font-family: 'Outfit', sans-serif;
                font-weight: 300;
                font-size: 0.936rem;
                color: var(--fg);
                letter-spacing: 0.18em;
                text-transform: uppercase;
                text-decoration: none;
                padding: 0.85rem 2rem;
                transition: opacity 0.2s;
            }

            .mobile-menu a:hover,
            .mobile-menu a:focus {
                opacity: 0.65;
            }
        }

        /* Hidden on desktop; flex on mobile via breakpoint */
        .nav-toggle {
            display: none;
            width: 44px;
            height: 44px;
            background: transparent;
            border: none;
            cursor: pointer;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            gap: 5px;
            padding: 0;
            flex-shrink: 0;
        }

        .nav-toggle-bar {
            display: block;
            width: 22px;
            height: 1.5px;
            background: var(--fg);
            transition: transform 0.3s ease, opacity 0.25s ease;
            transform-origin: center;
        }

        /*
         * Three bars → ×:
         * Bars are 1.5px tall with 5px gaps → centre of bar 1 sits 6.5px
         * above the middle, bar 3 sits 6.5px below → translateY brings
         * each to the midpoint before rotating.
         */
        .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
            transform: translateY(6.5px) rotate(45deg);
        }
        .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
            opacity: 0;
            transform: scaleX(0.1);
        }
        .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
            transform: translateY(-6.5px) rotate(-45deg);
        }

        /* ── Reduced motion (SC 2.3.3 AAA) ── */
        @media (prefers-reduced-motion: reduce) {
            html {
                scroll-behavior: auto;
            }
            *, *::before, *::after {
                transition-duration: 0.01ms !important;
                animation-duration: 0.01ms !important;
            }
        }

        /* ── Responsive: Tablet (≤768px) ── */
        @media (max-width: 768px) {
            .nav-inner {
                padding: 1.1rem 1.5rem;
            }

            .nav-toggle {
                display: flex;
            }

            /* Hide the desktop nav-links list on mobile; mobile-menu overlay takes over */
            .nav-links {
                display: none;
            }

            section {
                padding: 5rem 1.5rem;
            }

            .pillars-header {
                margin-bottom: 3.5rem;
            }

            .scale-grid {
                grid-template-columns: repeat(2, 1fr);
            }

            .scale-item:nth-child(2) {
                border-right: none;
            }

            .scale-item:nth-child(1),
            .scale-item:nth-child(2) {
                border-bottom: 1px solid var(--grey-rule);
            }

            .pillars-grid {
                grid-template-columns: 1fr;
                gap: 2.5rem;
            }

            footer {
                padding: 2rem 1.5rem;
                flex-direction: column;
                gap: 0.75rem;
                text-align: center;
            }
        }

        /* ── Responsive: Mobile (≤480px) ── */
        @media (max-width: 480px) {
            section {
                padding: 4.5rem 1.25rem;
            }

            .hero {
                padding: 7rem 1.25rem 5rem;
            }

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

            .scale-item {
                border-right: none;
                border-bottom: 1px solid var(--grey-rule);
                padding: 2rem 1.25rem;
            }

            .scale-item:last-child {
                border-bottom: none;
            }

            .pillars-grid {
                gap: 2rem;
            }

            .hero-scroll {
                display: none;
            }
        }