/*! Copyright (c) 2026 Papillon Corporation Limited. All rights reserved. No licence is granted to copy, modify or reuse this code. https://papcor.com/ */
/* Papillon Corporation sites: shared design system.

   Art direction: metamorphosis. The logo's two wings set the palette. The cool wing
   is the problem as it stands; the warm wing is how it ends up. Every illustration
   runs cool to warm, left to right. Type is a soft, high-contrast serif set large
   and tight, over a deep ink ground, with small monospaced labels for structure.
   Dark by default; a warm paper scheme when the visitor prefers light. */

@font-face {
    font-family: "Papillon Display";
    src: url("fonts/fraunces-display.woff2") format("woff2");
    font-weight: 400 800;
    font-style: normal;
    font-display: swap;
}

:root {
    color-scheme: dark light;

    --cool-1: #22d3ee;
    --cool-2: #4f8dff;
    --cool-3: #8b5cf6;
    --warm-1: #f0489f;
    --warm-2: #fb923c;
    --warm-3: #fbbf24;
    --wings: linear-gradient(90deg, var(--cool-1), var(--cool-2), var(--cool-3), var(--warm-1), var(--warm-2), var(--warm-3));
    --warm: linear-gradient(90deg, var(--warm-1), var(--warm-2), var(--warm-3));

    --bg: #070b16;
    --surface: #0d1424;
    --surface-2: #131c31;
    --line: rgba(160, 176, 204, 0.2);
    --text: #d9e2ef;
    --muted: #9fadc4;
    --strong: #ffffff;
    --link: #8cc8ff;
    --focus: #ffd166;
    --btn-a: #2f5fd0;
    --btn-b: #6548e0;
    --btn-text: #ffffff;
    --good: #fbbf24;
    --glow-cool: rgba(79, 141, 255, 0.2);
    --glow-warm: rgba(240, 72, 159, 0.14);

    --max: 1200px;
    --gap: clamp(16px, 2.2vw, 30px);
    --pad: clamp(18px, 4.5vw, 44px);
    --section: clamp(64px, 10vw, 136px);
    --radius: 18px;

    --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-head: "Papillon Display", "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
    --font-mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
}

@media (prefers-color-scheme: light) {
    :root {
        --bg: #f8f5ef;
        --surface: #fffdf9;
        --surface-2: #efebe2;
        --line: rgba(26, 31, 44, 0.16);
        --text: #2a3140;
        --muted: #505c72;
        --strong: #0b1020;
        --link: #1d4ed8;
        --focus: #b45309;
        --good: #b45309;
        --glow-cool: rgba(79, 141, 255, 0.14);
        --glow-warm: rgba(251, 146, 60, 0.14);
        --wings: linear-gradient(90deg, #0891b2, #2563eb, #7c3aed, #db2777, #ea580c, #b45309);
        --warm: linear-gradient(90deg, #db2777, #ea580c, #b45309);
    }
}

/* A theme the visitor chose with the header switch wins over the device setting. */
:root[data-theme="dark"] {
    color-scheme: dark;
    --bg: #070b16;
    --surface: #0d1424;
    --surface-2: #131c31;
    --line: rgba(160, 176, 204, 0.2);
    --text: #d9e2ef;
    --muted: #9fadc4;
    --strong: #ffffff;
    --link: #8cc8ff;
    --focus: #ffd166;
    --good: #fbbf24;
    --glow-cool: rgba(79, 141, 255, 0.2);
    --glow-warm: rgba(240, 72, 159, 0.14);
    --wings: linear-gradient(90deg, var(--cool-1), var(--cool-2), var(--cool-3), var(--warm-1), var(--warm-2), var(--warm-3));
    --warm: linear-gradient(90deg, var(--warm-1), var(--warm-2), var(--warm-3));
}

:root[data-theme="light"] {
    color-scheme: light;
    --bg: #f8f5ef;
    --surface: #fffdf9;
    --surface-2: #efebe2;
    --line: rgba(26, 31, 44, 0.16);
    --text: #2a3140;
    --muted: #505c72;
    --strong: #0b1020;
    --link: #1d4ed8;
    --focus: #b45309;
    --good: #b45309;
    --glow-cool: rgba(79, 141, 255, 0.14);
    --glow-warm: rgba(251, 146, 60, 0.14);
    --wings: linear-gradient(90deg, #0891b2, #2563eb, #7c3aed, #db2777, #ea580c, #b45309);
    --warm: linear-gradient(90deg, #db2777, #ea580c, #b45309);
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

* {
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 104px;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-body);
    font-size: clamp(1rem, 0.96rem + 0.2vw, 1.1rem);
    line-height: 1.65;
    background: var(--bg);
    color: var(--text);
    -webkit-font-smoothing: antialiased;
    overflow-x: clip;
}

img,
svg,
canvas {
    max-width: 100%;
}

img,
svg {
    height: auto;
}

a {
    color: var(--link);
    text-decoration-thickness: 1px;
    text-underline-offset: 3px;
}

a:hover {
    text-decoration-thickness: 2px;
}

:focus-visible {
    outline: 3px solid var(--focus);
    outline-offset: 3px;
    border-radius: 6px;
}

h1,
h2,
h3 {
    color: var(--strong);
    font-family: var(--font-head);
    font-optical-sizing: auto;
    font-weight: 560;
    line-height: 1.04;
    letter-spacing: -0.028em;
    text-wrap: balance;
}

h1 {
    font-size: clamp(2.7rem, 1.2rem + 6.6vw, 6.4rem);
    line-height: 0.98;
    letter-spacing: -0.04em;
}

h2 {
    font-size: clamp(2rem, 1.2rem + 3.4vw, 3.9rem);
    margin-bottom: 0.4em;
}

h3 {
    font-size: clamp(1.25rem, 1.1rem + 0.6vw, 1.6rem);
    line-height: 1.15;
    letter-spacing: -0.015em;
    margin-bottom: 0.45em;
}

p {
    text-wrap: pretty;
}

/* A phrase picked out in the warm wing's colours. */
.warm {
    background: var(--warm);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    padding-bottom: 0.08em;
}

.wrap {
    width: min(100% - 2 * var(--pad), var(--max));
    margin-inline: auto;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip-path: inset(50%);
    white-space: nowrap;
}

.skip {
    position: absolute;
    left: 12px;
    top: -80px;
    z-index: 30;
    background: var(--strong);
    color: var(--bg);
    padding: 12px 18px;
    border-radius: 8px;
    font-weight: 600;
}

.skip:focus {
    top: 12px;
}

section[id],
main[id] {
    scroll-margin-top: 96px;
}

/* Header */

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: color-mix(in srgb, var(--bg) 82%, transparent);
    backdrop-filter: blur(14px) saturate(1.3);
}

.site-header::after {
    content: "";
    display: block;
    height: 2px;
    background: var(--wings);
    opacity: 0.9;
}

.site-header .wrap {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px 24px;
    flex-wrap: wrap;
    padding-block: 8px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    min-height: 48px;
    color: var(--strong);
    font-family: var(--font-head);
    font-weight: 600;
    font-size: 1.28rem;
    letter-spacing: -0.02em;
    text-decoration: none;
}

.brand img {
    width: 34px;
    height: 34px;
}

.site-nav {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 4px;
    list-style: none;
}

.site-nav a {
    display: inline-flex;
    align-items: center;
    min-height: 48px;
    padding: 0 14px;
    color: var(--text);
    text-decoration: none;
    border-radius: 10px;
    font-size: 0.98rem;
}

.site-nav a:hover {
    color: var(--strong);
    background: var(--surface-2);
}

.site-header nav {
    margin-left: auto;
}

.site-header .header-cta {
    order: 3;
    min-height: 48px;
    padding: 0 20px;
}

.site-nav a[aria-current="page"] {
    color: var(--strong);
    box-shadow: inset 0 -2px 0 var(--warm-2);
    border-radius: 0;
}

/* The light and dark switch. Hidden until scripting has set it up. */
.theme-toggle {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    min-height: 44px;
    margin-left: 6px;
    padding: 0 14px;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: transparent;
    color: var(--text);
    font: inherit;
    font-size: 0.9rem;
    cursor: pointer;
}

.theme-toggle[hidden] {
    display: none;
}

.theme-toggle::before {
    content: "";
    width: 14px;
    height: 14px;
    border-radius: 50%;
    border: 2px solid currentColor;
    background: linear-gradient(90deg, currentColor 50%, transparent 50%);
}

.theme-toggle:hover {
    border-color: var(--muted);
    color: var(--strong);
}

/* Buttons */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 54px;
    padding: 0 28px;
    border-radius: 999px;
    border: 1px solid transparent;
    font: inherit;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: transform 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease;
}

.btn-primary {
    background: linear-gradient(135deg, var(--btn-a), var(--btn-b));
    color: var(--btn-text);
    box-shadow: 0 10px 30px -12px var(--btn-b);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 16px 36px -12px var(--btn-b);
}

.btn-ghost {
    background: transparent;
    color: var(--strong);
    border-color: var(--line);
}

.btn-ghost:hover {
    background: var(--surface-2);
    border-color: var(--muted);
}

/* Hero */

.hero {
    position: relative;
    isolation: isolate;
    padding-block: clamp(56px, 9vw, 124px) clamp(48px, 7vw, 96px);
    overflow: clip;
}

.hero::before {
    content: "";
    position: absolute;
    inset: -20% -10% auto -10%;
    height: 120%;
    z-index: -2;
    background:
        radial-gradient(50% 55% at 12% 20%, var(--glow-cool), transparent 70%),
        radial-gradient(45% 50% at 92% 30%, var(--glow-warm), transparent 70%);
}

.hero .wrap {
    display: grid;
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: var(--gap) clamp(24px, 5vw, 72px);
    align-items: center;
}

/* A hero whose artwork fills the section behind the words. */
.hero-full {
    min-height: min(92svh, 900px);
    display: grid;
    align-items: center;
}

.hero-full .wrap {
    grid-template-columns: minmax(0, 1fr);
}

.hero-full .hero-copy {
    max-width: 56rem;
}

.hero-canvas {
    position: absolute;
    inset: 0;
    z-index: -1;
    width: 100%;
    height: 100%;
    opacity: 0.9;
    -webkit-mask-image: linear-gradient(180deg, transparent 0, #000 22%, #000 78%, transparent 100%);
    mask-image: linear-gradient(180deg, transparent 0, #000 22%, #000 78%, transparent 100%);
}

.hero-full::after {
    content: "";
    position: absolute;
    inset: 0;
    z-index: -1;
    background: linear-gradient(90deg, color-mix(in srgb, var(--bg) 62%, transparent) 0, color-mix(in srgb, var(--bg) 46%, transparent) 40%, transparent 70%);
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 22px;
}

.eyebrow::before {
    content: "";
    width: 44px;
    height: 2px;
    background: var(--wings);
}

.hero h1 {
    margin-bottom: 0.4em;
}

.lead {
    font-size: clamp(1.1rem, 1rem + 0.6vw, 1.38rem);
    line-height: 1.55;
    max-width: 36em;
    margin-bottom: 1.7em;
}

.actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.hero-art {
    width: 100%;
}

.hero-art figcaption {
    color: var(--muted);
    font-size: 0.9rem;
    margin-top: 10px;
}

.motion-toggle {
    margin-top: 1.2em;
    min-height: 44px;
    padding: 0 14px;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: transparent;
    color: var(--muted);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    letter-spacing: 0.08em;
    cursor: pointer;
}

.motion-toggle:not(.is-ready) {
    visibility: hidden;
}

.motion-toggle:hover {
    color: var(--strong);
    border-color: var(--muted);
}


/* Proof strip */

.proof {
    border-block: 1px solid var(--line);
    background: var(--surface);
}

.proof .wrap {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0;
}

.proof .wrap > div {
    padding: clamp(22px, 3vw, 38px) clamp(14px, 2vw, 28px);
    border-left: 1px solid var(--line);
}

.proof .wrap > div:first-child,
.proof .wrap > div:nth-child(odd) {
    border-left: 0;
    padding-left: 0;
}

.proof strong {
    display: block;
    color: var(--strong);
    font-family: var(--font-head);
    font-weight: 560;
    font-size: clamp(1.6rem, 1.1rem + 1.9vw, 2.7rem);
    line-height: 1.05;
    letter-spacing: -0.03em;
    margin-bottom: 8px;
}

.proof .wrap > div > span {
    color: var(--muted);
    font-size: 0.95rem;
}

/* Sections */

.section {
    position: relative;
    padding-block: var(--section);
}

.section.tint {
    background: var(--surface);
    border-block: 1px solid var(--line);
}

/* A small numbered label above a section heading. */
.kicker {
    display: flex;
    align-items: center;
    gap: 14px;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 20px;
}

.kicker::after {
    content: "";
    flex: 1;
    height: 1px;
    background: var(--line);
}

.intro {
    color: var(--muted);
    font-size: clamp(1.05rem, 1rem + 0.3vw, 1.22rem);
    max-width: 40em;
    margin-bottom: clamp(28px, 4.5vw, 56px);
}

/* Cards */

.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr));
    gap: var(--gap);
}

.card {
    position: relative;
    background: var(--surface-2);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: clamp(22px, 3vw, 34px);
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.card::before {
    content: "";
    position: absolute;
    left: clamp(22px, 3vw, 34px);
    top: 0;
    width: 56px;
    height: 3px;
    border-radius: 0 0 3px 3px;
    background: var(--wings);
}

.card:hover {
    transform: translateY(-4px);
    border-color: var(--muted);
}

.card p + p {
    margin-top: 0.8em;
}

.cards.four {
    grid-template-columns: 1fr;
}

@media (min-width: 640px) {
    .cards.four {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 1180px) {
    .cards.four {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }

    .proof .wrap {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }

    .proof .wrap > div:nth-child(odd) {
        border-left: 1px solid var(--line);
        padding-left: clamp(14px, 2vw, 28px);
    }

    .proof .wrap > div:first-child {
        border-left: 0;
        padding-left: 0;
    }
}

.ticks {
    list-style: none;
    margin-top: 0.9em;
}

.ticks li {
    position: relative;
    padding-left: 28px;
    margin-bottom: 0.55em;
}

.ticks li::before {
    content: "";
    position: absolute;
    left: 2px;
    top: 0.55em;
    width: 12px;
    height: 6px;
    border-left: 2px solid var(--good);
    border-bottom: 2px solid var(--good);
    transform: rotate(-45deg);
}

.evidence {
    margin-top: 1.1em;
    padding-top: 1em;
    border-top: 1px solid var(--line);
    color: var(--muted);
    font-size: 0.97rem;
}

/* Problem chooser: tabs when scripted, a plain list of panels otherwise */

.chooser-tabs {
    display: none;
}

.chooser.is-ready .chooser-tabs {
    display: grid;
    grid-template-columns: 1fr;
    gap: 10px;
    margin-bottom: var(--gap);
    counter-reset: tab;
}

@media (min-width: 600px) {
    .chooser.is-ready .chooser-tabs {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

/* On wide screens the choices sit beside the answer. */
@media (min-width: 1040px) {
    .chooser.is-ready {
        display: grid;
        grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
        gap: clamp(24px, 3vw, 48px);
        align-items: start;
    }

    .chooser.is-ready .chooser-tabs {
        grid-template-columns: 1fr;
        margin-bottom: 0;
        position: sticky;
        top: 110px;
    }
}

.chooser-tabs button {
    counter-increment: tab;
    display: flex;
    align-items: baseline;
    gap: 16px;
    min-height: 72px;
    padding: 16px 20px;
    text-align: left;
    font-family: var(--font-head);
    font-size: clamp(1.1rem, 1rem + 0.5vw, 1.4rem);
    font-weight: 500;
    line-height: 1.2;
    letter-spacing: -0.015em;
    color: var(--muted);
    background: transparent;
    border: 1px solid var(--line);
    border-radius: 14px;
    cursor: pointer;
    transition: color 0.18s ease, border-color 0.18s ease, background-color 0.18s ease;
}

.chooser-tabs button::before {
    content: "0" counter(tab);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    letter-spacing: 0.1em;
    color: var(--muted);
}

.chooser-tabs button:hover {
    color: var(--strong);
    border-color: var(--muted);
}

.chooser-tabs button[aria-selected="true"] {
    color: var(--strong);
    background:
        linear-gradient(var(--surface-2), var(--surface-2)) padding-box,
        var(--wings) border-box;
    border: 2px solid transparent;
}

.panel {
    background: var(--surface-2);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: clamp(22px, 3.6vw, 44px);
    margin-bottom: var(--gap);
}

.panel h3 {
    font-size: clamp(1.5rem, 1.2rem + 1.4vw, 2.3rem);
    letter-spacing: -0.025em;
}

.chooser.is-ready .panel {
    margin-bottom: 0;
}

.chooser.is-ready .panel[hidden] {
    display: none;
}

.panel-action {
    margin-top: 1.4em;
}

.panel-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 240px), 1fr));
    gap: var(--gap);
    margin-block: 1.4em;
}

.panel-grid h4 {
    font-family: var(--font-mono);
    color: var(--muted);
    font-size: 0.76rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    margin-bottom: 0.6em;
}

/* Steps */

.form-status {
    color: var(--strong);
}

.form-error {
    color: var(--strong);
    border-left: 3px solid var(--warm-2);
    padding-left: 10px;
}

[aria-invalid="true"] {
    border-color: var(--warm-2) !important;
    border-width: 2px;
}

.steps {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--gap);
    counter-reset: step;
    list-style: none;
}

@media (min-width: 760px) {
    .steps {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

.steps li {
    counter-increment: step;
    padding-top: 22px;
    border-top: 2px solid;
    border-image: var(--wings) 1;
}

.steps li::before {
    content: "0" counter(step);
    display: block;
    font-family: var(--font-head);
    font-weight: 500;
    font-size: clamp(2.6rem, 2rem + 2.6vw, 4.4rem);
    line-height: 1;
    letter-spacing: -0.04em;
    color: var(--muted);
    opacity: 0.55;
    margin-bottom: 14px;
}

/* Scale story */

.scale {
    display: grid;
    gap: 14px;
    margin-block: 1.6em;
}

.scale-row {
    display: grid;
    grid-template-columns: minmax(8.5em, auto) 1fr;
    gap: 14px;
    align-items: center;
}

.scale-label {
    font-family: var(--font-mono);
    font-size: 0.86rem;
    letter-spacing: 0.04em;
    color: var(--strong);
}

.scale-bar {
    height: 26px;
    border-radius: 999px;
    background: var(--surface-2);
    border: 1px solid var(--line);
    overflow: hidden;
}

.scale-bar i {
    display: block;
    height: 100%;
    border-radius: 999px;
}

.scale-bar .before {
    width: 100%;
    background: linear-gradient(90deg, var(--cool-1), var(--cool-2), var(--cool-3));
}

.scale-bar .after {
    width: 3px;
    background: var(--warm-3);
}

/* A number set very large. */
.figure-xl {
    font-family: var(--font-head);
    font-weight: 560;
    font-size: clamp(3.4rem, 1.4rem + 9vw, 9.5rem);
    line-height: 0.92;
    letter-spacing: -0.05em;
    color: var(--strong);
    margin-bottom: 0.18em;
}

.race {
    background: var(--surface-2);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: clamp(18px, 3vw, 32px);
}

.race .scale {
    margin-top: 0;
}

.race-note {
    color: var(--muted);
    margin-top: 12px;
    min-height: 3.2em;
}


/* Questions */

.faq details {
    border-bottom: 1px solid var(--line);
}

.faq details:first-child {
    border-top: 1px solid var(--line);
}

.faq summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    min-height: 68px;
    padding-block: 14px;
    cursor: pointer;
    color: var(--strong);
    font-family: var(--font-head);
    font-weight: 500;
    font-size: clamp(1.1rem, 1rem + 0.5vw, 1.42rem);
    letter-spacing: -0.015em;
    list-style: none;
}

.faq summary::-webkit-details-marker {
    display: none;
}

.faq summary::after {
    content: "+";
    flex: none;
    display: grid;
    place-items: center;
    width: 36px;
    height: 36px;
    border: 1px solid var(--line);
    border-radius: 50%;
    font-family: var(--font-body);
    font-size: 1.3rem;
    line-height: 1;
    color: var(--muted);
}

.faq details[open] summary::after {
    content: "\2212";
    color: var(--strong);
    border-color: var(--muted);
}

.faq details p {
    max-width: 46em;
    padding-bottom: 22px;
}

/* About */

.split {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 320px), 1fr));
    gap: clamp(24px, 5vw, 72px);
    align-items: start;
}

.split p + p {
    margin-top: 1em;
}

.record {
    list-style: none;
    border-top: 1px solid var(--line);
}

.record li {
    padding-block: 16px;
    border-bottom: 1px solid var(--line);
}

.record strong,
.prose strong {
    color: var(--strong);
}

.record strong {
    display: block;
    font-family: var(--font-head);
    font-weight: 560;
    font-size: 1.2rem;
    letter-spacing: -0.015em;
}

.prose {
    max-width: 46em;
}

.prose p + p,
.prose ul + p,
.prose p + ul {
    margin-top: 1em;
}

.prose ul {
    padding-left: 1.2em;
}

.prose li {
    margin-bottom: 0.5em;
}

.prose h2 {
    font-size: clamp(1.4rem, 1.2rem + 0.9vw, 1.95rem);
    margin-top: 1.7em;
}

.prose h2 + p,
.prose h2 + ul {
    margin-top: 0.6em;
}

/* Forms */

.form {
    display: grid;
    gap: 18px;
    max-width: 640px;
}

.field {
    display: grid;
    gap: 6px;
}

.field label,
.field legend {
    color: var(--strong);
    font-weight: 600;
}

.field small {
    color: var(--muted);
}

.field-pair {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 200px), 1fr));
    gap: 14px;
}

.optional {
    color: var(--muted);
    font-weight: 400;
}

/* A field real visitors never see or reach; automated form-fillers complete it. */
.trap {
    position: absolute;
    left: -9999px;
    width: 1px;
    height: 1px;
    overflow: hidden;
}

.form-status:focus {
    outline: none;
}

.form button[disabled] {
    opacity: 0.6;
    cursor: progress;
}

/* Messages on the page shown after a form is sent without scripting. */
.notice {
    max-width: 40em;
}

#problem {
    display: none;
}

#problem:target {
    display: block;
}

#problem:target ~ #received {
    display: none;
}

input[type="text"],
input[type="number"],
input[type="email"],
input[type="tel"],
select,
textarea {
    width: 100%;
    min-height: 52px;
    padding: 10px 14px;
    font: inherit;
    color: var(--strong);
    background: var(--bg);
    border: 1px solid var(--line);
    border-radius: 12px;
}

textarea {
    min-height: 130px;
    resize: vertical;
}

input:hover,
select:hover,
textarea:hover {
    border-color: var(--muted);
}

/* Tables */

.table-scroll {
    overflow-x: auto;
}

.prices {
    width: 100%;
    max-width: 780px;
    border-collapse: collapse;
}

.prices th,
.prices td {
    text-align: left;
    padding: 16px;
    border-bottom: 1px solid var(--line);
}

.prices thead th {
    font-family: var(--font-mono);
    font-size: 0.76rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--muted);
    font-weight: 600;
}

.prices tbody th {
    color: var(--strong);
    font-weight: 600;
}

.prices .num {
    text-align: right;
    white-space: nowrap;
    font-variant-numeric: tabular-nums;
}

/* Contact band */

.contact {
    position: relative;
    isolation: isolate;
    padding-block: var(--section);
    border-top: 1px solid var(--line);
    overflow: clip;
}

.contact::before {
    content: "";
    position: absolute;
    inset: auto -10% -40% -10%;
    height: 90%;
    z-index: -1;
    background:
        radial-gradient(40% 60% at 20% 100%, var(--glow-cool), transparent 70%),
        radial-gradient(40% 60% at 80% 100%, var(--glow-warm), transparent 70%);
}

.contact .wrap {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 320px), 1fr));
    gap: clamp(24px, 5vw, 72px);
    align-items: start;
}

.contact h2 {
    font-size: clamp(2.3rem, 1.2rem + 4.6vw, 5rem);
}

.contact .form {
    background: color-mix(in srgb, var(--surface-2) 86%, transparent);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: clamp(18px, 3vw, 32px);
}

/* Footer */

.site-footer {
    border-top: 1px solid var(--line);
    padding-block: 28px;
    color: var(--muted);
    font-size: 0.95rem;
}

.site-footer .wrap {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 10px 24px;
}

.site-footer a {
    color: var(--muted);
    display: inline-block;
    padding-block: 12px;
}

.site-footer .legal {
    flex: 1 1 100%;
    order: 3;
    font-size: 0.85rem;
}

.site-footer .sisters a {
    margin-left: 16px;
}

/* The name, very large, closing the page. */
.wordmark {
    display: block;
    font-family: var(--font-head);
    font-weight: 560;
    font-size: clamp(3.4rem, 0.6rem + 16vw, 17rem);
    line-height: 1;
    letter-spacing: -0.06em;
    color: transparent;
    -webkit-text-stroke: 1px var(--line);
    user-select: none;
    flex: 0 0 100%;
    padding-top: clamp(28px, 5vw, 64px);
    padding-bottom: 0.12em;
    white-space: nowrap;
}

/* The opening of a page other than the front page. */

.page-hero {
    position: relative;
    isolation: isolate;
    padding-block: clamp(48px, 7vw, 104px) clamp(36px, 5vw, 72px);
    overflow: clip;
}

.page-hero::before {
    content: "";
    position: absolute;
    inset: -30% -10% auto -10%;
    height: 130%;
    z-index: -1;
    background:
        radial-gradient(50% 55% at 10% 20%, var(--glow-cool), transparent 70%),
        radial-gradient(45% 50% at 92% 30%, var(--glow-warm), transparent 70%);
}

.page-hero h1 {
    font-size: clamp(2.4rem, 1.2rem + 5.2vw, 5.4rem);
    max-width: 14em;
    margin-bottom: 0.35em;
}

.page-hero .lead {
    margin-bottom: 0;
}

.page-hero .actions {
    margin-top: 1.6em;
}

.note {
    color: var(--muted);
    font-size: 0.92rem;
    max-width: 52em;
}

.note.after {
    margin-top: clamp(20px, 3vw, 36px);
}

/* Doors: large links out to the other things to look at. */

.doors {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 300px), 1fr));
    gap: var(--gap);
}

.door {
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding: clamp(22px, 3vw, 34px);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--surface-2);
    color: var(--text);
    text-decoration: none;
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.door:hover {
    transform: translateY(-4px);
    border-color: var(--muted);
}

.door small {
    font-family: var(--font-mono);
    font-size: 0.74rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--muted);
}

.door strong {
    font-family: var(--font-head);
    font-weight: 560;
    font-size: clamp(1.5rem, 1.2rem + 1.2vw, 2.1rem);
    line-height: 1.08;
    letter-spacing: -0.025em;
    color: var(--strong);
}

.door em {
    margin-top: auto;
    padding-top: 14px;
    font-style: normal;
    font-weight: 600;
    color: var(--link);
}

.door em::after {
    content: " \2192";
}

/* Three points side by side under a rule. */

.pillars {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr));
    gap: var(--gap);
}

.pillars > div {
    padding-top: 18px;
    border-top: 2px solid;
    border-image: var(--wings) 1;
}

/* The learning demonstration: a world to watch, its controls and its figures. */

.demo {
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--surface-2);
    padding: clamp(14px, 2.4vw, 28px);
}

.demo canvas {
    display: block;
    width: 100%;
    border: 1px solid var(--line);
    background: var(--bg);
}

.demo .world {
    aspect-ratio: 5 / 3;
    border-radius: 12px;
}

.demo-bar + canvas {
    margin-top: 14px;
}

.demo > .demo-bar:first-child {
    margin-top: 0;
}

.demo .chart {
    height: 64px;
    margin-top: 14px;
    border-radius: 8px;
}

.demo-mode {
    margin-top: 14px;
    min-height: 3.3em;
}

.demo-bar [role="group"] {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.demo-bar [data-speed],
.demo-bar [data-way] {
    min-height: 48px;
    padding: 0 16px;
    border: 1px solid var(--line);
    border-radius: 999px;
    background: transparent;
    color: var(--text);
    font: inherit;
    cursor: pointer;
}

.demo-bar [data-speed]:hover,
.demo-bar [data-way]:hover {
    border-color: var(--muted);
}

.demo-bar [data-speed][aria-pressed="true"],
.demo-bar [data-way][aria-pressed="true"] {
    background: var(--strong);
    border-color: var(--strong);
    color: var(--bg);
    font-weight: 600;
}

.demo-bar .btn[disabled] {
    opacity: 0.5;
    cursor: default;
}

.demo-bar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 12px 20px;
    margin-top: 16px;
}

.demo-bar .btn {
    min-height: 48px;
    padding: 0 20px;
}

.readout {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 200px), 1fr));
    gap: 14px;
    margin-top: 18px;
}

.readout div {
    padding-top: 12px;
    border-top: 2px solid var(--line);
}

.readout div.hot {
    border-image: var(--warm) 1;
}

.readout dt {
    font-family: var(--font-mono);
    font-size: 0.74rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--muted);
}

.readout dd {
    font-family: var(--font-head);
    font-weight: 560;
    font-size: clamp(1.7rem, 1.2rem + 1.8vw, 2.8rem);
    line-height: 1.1;
    letter-spacing: -0.03em;
    color: var(--strong);
    font-variant-numeric: tabular-nums;
}

.readout dd + dd {
    font-family: var(--font-body);
    font-weight: 400;
    font-size: 0.9rem;
    letter-spacing: 0;
    color: var(--muted);
}

/* The steps a change goes through, ending with a person. */

.flow {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 190px), 1fr));
    counter-reset: flow;
    list-style: none;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    overflow: hidden;
}

.flow li {
    position: relative;
    counter-increment: flow;
    margin: 0 -1px -1px 0;
    padding: clamp(18px, 2.2vw, 28px);
    background: var(--surface-2);
    border-right: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.flow li::before {
    content: "0" counter(flow);
    display: block;
    font-family: var(--font-mono);
    font-size: 0.76rem;
    font-weight: 600;
    letter-spacing: 0.12em;
    color: var(--muted);
    margin-bottom: 12px;
}

.flow h3 {
    font-size: 1.25rem;
}

.flow p {
    font-size: 0.97rem;
}

.flow .person {
    background: var(--surface);
}

.flow .person h3 {
    background: var(--warm);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

@media (forced-colors: active) {
    .flow .person h3 {
        color: CanvasText;
        background: none;
    }
}

/* Narrow screens */

@media (max-width: 820px) {
    .hero .wrap {
        grid-template-columns: 1fr;
    }

    .site-header .header-cta {
        order: 0;
        margin-left: auto;
    }

    .site-header nav {
        flex: 1 1 100%;
        margin-left: 0;
    }

    .site-nav {
        width: 100%;
        gap: 0 4px;
    }

    .site-nav a {
        padding: 0 12px;
    }

    .site-nav li:first-child a {
        padding-left: 0;
    }

    .hero-full::after {
        background: linear-gradient(180deg, color-mix(in srgb, var(--bg) 70%, transparent), color-mix(in srgb, var(--bg) 86%, transparent));
    }
}

@media (max-height: 520px) {
    .site-header {
        position: static;
    }

    .hero-full {
        min-height: 0;
    }
}

@media (min-width: 1500px) {
    :root {
        --max: 1360px;
    }
}

@media (max-width: 480px) {
    .site-header {
        position: static;
    }

    .site-header .wrap {
        gap: 0 10px;
        padding-block: 4px;
    }

    .brand {
        font-size: 1.05rem;
        gap: 8px;
        min-height: 44px;
    }

    .brand img {
        width: 26px;
        height: 26px;
    }

    .site-header .header-cta {
        min-height: 44px;
        padding: 0 12px;
        font-size: 0.92rem;
    }

    .site-nav a {
        min-height: 44px;
        min-width: 44px;
        justify-content: center;
        padding: 0 9px;
        font-size: 0.95rem;
    }

    .site-nav .nav-optional {
        display: none;
    }

    .actions .btn {
        width: 100%;
    }

    .scale-row {
        grid-template-columns: 1fr;
        gap: 6px;
    }

    .proof .wrap {
        grid-template-columns: 1fr;
    }

    .proof .wrap > div {
        border-left: 0;
        padding-left: 0;
        border-top: 1px solid var(--line);
    }

    .proof .wrap > div:first-child {
        border-top: 0;
    }
}

@media (max-width: 350px) {
    .brand {
        font-size: 0.95rem;
    }

    .brand img {
        display: none;
    }

    .site-header .header-cta {
        padding: 0 10px;
        font-size: 0.86rem;
    }

    .site-nav a {
        padding: 0 7px;
        font-size: 0.9rem;
    }
}

/* Pointer and motion preferences */

@media (hover: none) {
    .btn-primary:hover,
    .card:hover {
        transform: none;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

@media (prefers-reduced-motion: no-preference) {
    .draw path,
    .draw line,
    .draw polyline {
        stroke-dasharray: var(--len, 1200);
        stroke-dashoffset: var(--len, 1200);
        animation: draw 1.6s ease-out forwards;
    }

    .draw path:nth-child(2) {
        animation-delay: 0.12s;
    }

    .draw path:nth-child(3) {
        animation-delay: 0.24s;
    }

    .draw path:nth-child(4) {
        animation-delay: 0.36s;
    }

    .draw path:nth-child(5) {
        animation-delay: 0.48s;
    }

    @keyframes draw {
        to {
            stroke-dashoffset: 0;
        }
    }

    /* Sections rise into place as they come into view, where the browser can do it. */
    @supports (animation-timeline: view()) {
        .reveal {
            animation: rise linear both;
            animation-timeline: view();
            animation-range: entry 0% entry 45%;
        }

        @keyframes rise {
            from {
                transform: translateY(44px);
            }

            to {
                transform: none;
            }
        }
    }
}

@media (forced-colors: active) {
    .btn,
    .card,
    .panel,
    .chooser-tabs button {
        border: 1px solid CanvasText;
    }

    .chooser-tabs button[aria-selected="true"] {
        border: 3px solid Highlight;
        background: Canvas;
    }

    .warm,
    .wordmark {
        color: CanvasText;
        background: none;
        -webkit-text-stroke: 0;
    }

    .site-header::after,
    .scale-bar i {
        forced-color-adjust: none;
    }
}

@media print {
    .site-header,
    .actions,
    .hero-art,
    .hero-canvas,
    .chooser-tabs,
    .wordmark,
    .form {
        display: none !important;
    }

    body {
        background: #fff;
        color: #000;
    }

    .panel[hidden] {
        display: block !important;
    }
}