/*
  Paper & Hinge — site styles
  Paper and ink. Vermilion appears only where paper is folded: its coloured back.
  Layers keep specificity flat: later layers win regardless of selector weight.
*/
@layer reset, tokens, base, layout, components, art, motion;

/* ---------------------------------------------------------------- reset */
@layer reset {
  *, *::before, *::after { box-sizing: border-box; }
  html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
  body, h1, h2, h3, h4, p, figure, blockquote, dl, dd, ul, ol { margin: 0; }
  ul[class], ol[class], nav ul, nav ol, .footer-col ul, .lost ul { padding: 0; list-style: none; }
  img, svg { display: block; max-width: 100%; }
  svg { height: auto; }
}

/* --------------------------------------------------------------- tokens */
@layer tokens {
  :root {
    color-scheme: light dark;

    /* Day paper */
    --paper: #F4EFE6;          /* the page */
    --paper-deep: #E6DFD3;     /* recessed surfaces */
    --paper-lift: #FAF7F1;     /* a sheet lying on the page */
    --ink: #1F1B16;
    --ink-soft: #5C5247;       /* 6.7:1 on paper, 5.8:1 on paper-deep */
    --ink-faint: rgb(31 27 22 / 0.28);
    --vermilion: #E0452B;      /* graphics, rules, large text only */
    --vermilion-deep: #B8371F;
    --vermilion-shade: #CC3D25;
    --vermilion-ink: #B3341C;  /* text in vermilion: 5.4:1 on paper */
    --link: var(--vermilion-ink);

    --crease-dark: rgb(31 27 22 / 0.17);
    --crease-light: rgb(255 255 255 / 0.8);
    --shade: rgb(31 27 22 / 0.055);
    --shadow: rgb(31 27 22 / 0.2);
    --shadow-soft: rgb(31 27 22 / 0.1);

    /* Origami paper in illustrations */
    --sheet: #FDFBF7;
    --sheet-shade: #E9E2D5;
    --sheet-edge: rgb(31 27 22 / 0.3);

    --grain-opacity: 0.36;

    --font-display: "Newsreader", "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
    --font-body: "Instrument Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;

    /* Type scale (after Bringhurst: 14 · 17 · 21 · 24 · 36 · 48 · 72) */
    --step--1: 0.875rem;
    --step-0: 1.0625rem;
    --step-1: 1.3125rem;
    --step-2: 1.5rem;
    --step-3: clamp(1.75rem, 1.4rem + 1.4vw, 2.25rem);
    --step-4: clamp(2.125rem, 1.5rem + 2.6vw, 3rem);
    --step-5: clamp(2.75rem, 1.4rem + 5.6vw, 5.25rem);
    --step-6: clamp(4rem, 2rem + 9vw, 8rem);

    --gutter: clamp(1rem, 0.4rem + 2.6vw, 2.5rem);
    --page-max: 74rem;
    --measure: 36rem;
    --space-s: 1rem;
    --space-m: 1.5rem;
    --space-l: clamp(2.5rem, 1.9rem + 2.4vw, 4rem);
    --space-xl: clamp(3.5rem, 2.2rem + 5.2vw, 7rem);
    --ear: clamp(1.75rem, 1.3rem + 1.6vw, 2.5rem);
  }

  /* Night paper: warm charcoal, like the desk the app's paper sits on. */
  @media (prefers-color-scheme: dark) {
    :root {
      --paper: #1C1A17;
      --paper-deep: #141210;
      --paper-lift: #25221E;
      --ink: #EDE5D8;
      --ink-soft: #B7AC9C;
      --ink-faint: rgb(237 229 216 / 0.3);
      --vermilion: #EC5A3E;
      --vermilion-deep: #B8371F;
      --vermilion-shade: #D24A30;
      --vermilion-ink: #F58A70;

      --crease-dark: rgb(0 0 0 / 0.6);
      --crease-light: rgb(255 255 255 / 0.07);
      --shade: rgb(0 0 0 / 0.22);
      --shadow: rgb(0 0 0 / 0.55);
      --shadow-soft: rgb(0 0 0 / 0.35);

      /* At night the origami paper is dark too, and the ink on it is light. */
      --sheet: #38332D;
      --sheet-shade: #2A2622;
      --sheet-edge: rgb(0 0 0 / 0.55);

      --grain-opacity: 0.45;
    }
  }
}

/* ----------------------------------------------------------------- base */
@layer base {
  html {
    background: var(--paper);
    color: var(--ink);
    font-family: var(--font-body);
    line-height: 1.6;
  }
  body {
    min-height: 100vh;
    background: var(--paper);
    font-size: var(--step-0);
    font-kerning: normal;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }
  @media (min-width: 64rem) {
    body { font-size: 1.125rem; }
  }

  h1, h2, h3, h4 {
    font-family: var(--font-display);
    font-weight: 400;
    font-optical-sizing: auto;
    line-height: 1.08;
    letter-spacing: -0.012em;
    text-wrap: balance;
  }
  h2 { font-size: var(--step-4); }
  h3 { font-size: var(--step-2); font-weight: 500; line-height: 1.2; letter-spacing: -0.005em; }
  p, li, dd, figcaption { text-wrap: pretty; }
  strong { font-weight: 600; }

  a {
    color: var(--link);
    text-decoration-line: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 0.2em;
  }
  a:hover { text-decoration-thickness: 2px; }
  a:focus-visible,
  summary:focus-visible,
  [tabindex]:focus-visible {
    outline: 3px solid var(--vermilion);
    outline-offset: 3px;
    border-radius: 2px;
  }
  ::selection { background: var(--vermilion); color: #fff; }

  .visually-hidden {
    position: absolute !important;
    width: 1px; height: 1px;
    padding: 0; margin: -1px;
    overflow: hidden; clip: rect(0 0 0 0);
    white-space: nowrap; border: 0;
  }

  .skip-link {
    position: absolute;
    left: var(--gutter);
    top: 0.75rem;
    z-index: 60;
    padding: 0.6rem 1rem;
    background: var(--ink);
    color: var(--paper);
    font-weight: 600;
    text-decoration: none;
    transform: translateY(-200%);
  }
  .skip-link:focus-visible { transform: none; }
}

/* --------------------------------------------------------------- layout */
@layer layout {
  .wrap {
    width: min(100% - 2 * var(--gutter), var(--page-max));
    margin-inline: auto;
  }
  .wrap--narrow { max-width: 46rem; }

  .section { padding-block: var(--space-xl); }
  .section--tight { padding-block: var(--space-l); }

  /* A fold across the page: dark line, light line, and a little valley shading below. */
  .fold { position: relative; }
  .fold::before {
    content: "";
    position: absolute;
    inset: 0 0 auto;
    height: 0.9rem;
    background:
      linear-gradient(var(--crease-dark) 0 1px, var(--crease-light) 1px 2px, transparent 2px),
      linear-gradient(var(--shade), transparent);
    pointer-events: none;
  }

  .section-head { max-width: 42rem; margin-bottom: var(--space-l); }
  .section-head > p {
    margin-top: 1rem;
    font-size: var(--step-1);
    line-height: 1.5;
    color: var(--ink-soft);
  }

  /* ---- Site header */
  .masthead {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 0.25rem 2rem;
    padding-block: 1rem 0.75rem;
  }
  .wordmark {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding-block: 0.35rem;
    color: var(--ink);
    font-family: var(--font-display);
    font-size: 1.375rem;
    font-weight: 500;
    letter-spacing: -0.01em;
    text-decoration: none;
  }
  .wordmark .mark { width: 1.75rem; height: 1.75rem; flex: none; }
  .site-nav ul {
    display: flex;
    flex-wrap: wrap;
    gap: 0 1.35rem;
  }
  .site-nav a {
    display: inline-block;
    padding-block: 0.6rem;
    color: var(--ink);
    font-weight: 500;
    text-decoration-line: none;
  }
  .site-nav a:hover { text-decoration-line: underline; text-decoration-thickness: 1px; }
  .site-nav a[aria-current="page"] {
    text-decoration-line: underline;
    text-decoration-color: var(--vermilion);
    text-decoration-thickness: 2px;
    text-underline-offset: 0.45em;
  }
  .masthead-rule { height: 2px; background: linear-gradient(var(--crease-dark) 0 1px, var(--crease-light) 1px 2px); }

  /* ---- Site footer: the back of the sheet */
  main { padding-bottom: var(--space-l); }
  main.ends-flush { padding-bottom: 0; }
  .site-footer {
    margin-top: 0;
    padding-block: var(--space-l) 2.5rem;
    background: var(--paper-deep);
    color: var(--ink);
  }
  .footer-grid {
    display: grid;
    gap: 2rem;
  }
  @media (min-width: 48rem) {
    .footer-grid { grid-template-columns: 1.3fr 1fr 1fr; align-items: start; }
  }
  .footer-studio p { margin-top: 0.75rem; max-width: 22rem; color: var(--ink-soft); }
  .footer-studio .wordmark { font-size: 1.25rem; }
  .footer-col h2 {
    font-family: var(--font-body);
    font-size: var(--step--1);
    font-weight: 600;
    letter-spacing: 0;
    color: var(--ink-soft);
  }
  .footer-col ul { margin-top: 0.5rem; }
  .footer-col a { display: inline-block; padding-block: 0.3rem; color: var(--ink); }
  .footer-fine {
    margin-top: 2.5rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--crease-dark);
    font-size: var(--step--1);
    color: var(--ink-soft);
  }
  .footer-fine p + p { margin-top: 0.35rem; }
}

/* ----------------------------------------------------------- components */
@layer components {

  /* ---- Display type */
  .display {
    font-size: var(--step-5);
    line-height: 1.0;
    letter-spacing: -0.022em;
  }
  .lede {
    font-size: var(--step-1);
    line-height: 1.5;
    max-width: 34rem;
  }

  /* ---- Landing intro */
  .intro {
    display: grid;
    gap: 1.5rem;
    padding-block: var(--space-l) var(--space-l);
  }
  @media (min-width: 60rem) {
    .intro {
      grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
      align-items: end;
      gap: 4rem;
      padding-block: var(--space-xl) var(--space-l);
    }
    .intro .lede { padding-bottom: 0.6rem; }
  }
  .intro .display { max-width: 11ch; }

  /* ---- The spread: two leaves joined by a hinge.
          Stacked (horizontal crease) on phones, side by side from 48rem. */
  .spread-shadow {
    filter: drop-shadow(0 1px 1px var(--shadow-soft)) drop-shadow(0 22px 26px var(--shadow-soft));
  }
  .spread {
    display: grid;
    perspective: 2000px;
  }
  .leaf {
    position: relative;
    padding: clamp(1.5rem, 0.9rem + 2.6vw, 3rem);
  }
  .spread--sheet .leaf { background-color: var(--paper-lift); }
  .leaf--a { background-image: linear-gradient(to bottom, transparent 60%, var(--shade)); }
  .leaf--b { background-image: linear-gradient(to top, transparent 70%, var(--shade)); }
  .leaf--b::before {
    content: "";
    position: absolute;
    inset: 0 0 auto 0;
    height: 2px;
    background: linear-gradient(var(--crease-dark) 0 1px, var(--crease-light) 1px 2px);
  }
  @media (min-width: 48rem) {
    .spread { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
    .leaf--a { background-image: linear-gradient(to right, transparent 62%, var(--shade)); }
    .leaf--b { background-image: linear-gradient(to left, transparent 72%, var(--shade)); }
    .leaf--b::before {
      inset: 0 auto 0 0;
      width: 2px;
      height: auto;
      background: linear-gradient(to right, var(--crease-dark) 0 1px, var(--crease-light) 1px 2px);
    }
  }
  /* A quiet spread sits on the page itself: only the crease and a narrow valley shading. */
  .spread--quiet .leaf { padding-inline: 0; }
  .spread--quiet .leaf--a { background-image: linear-gradient(to top, var(--shade), transparent 1.5rem); }
  .spread--quiet .leaf--b { background-image: linear-gradient(to bottom, var(--shade), transparent 1.5rem); }
  @media (min-width: 48rem) {
    .spread--quiet .leaf--a { background-image: linear-gradient(to left, var(--shade), transparent 2.5rem); }
    .spread--quiet .leaf--b { background-image: linear-gradient(to right, var(--shade), transparent 2.5rem); }
  }
  @media (min-width: 48rem) {
    .spread--quiet .leaf--a { padding-right: clamp(2rem, 4vw, 4rem); }
    .spread--quiet .leaf--b { padding-left: clamp(2rem, 4vw, 4rem); }
  }
  @media (max-width: 47.99rem) {
    .spread--quiet .leaf--a { padding-top: 0; }
  }

  /* ---- Folded corner: the sheet's corner turned down, showing the vermilion back */
  .dog-ear {
    clip-path: polygon(0 0, calc(100% - var(--ear)) 0, 100% var(--ear), 100% 100%, 0 100%);
  }
  .dog-ear::after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    width: var(--ear);
    height: var(--ear);
    background: linear-gradient(225deg, transparent 50%, var(--vermilion-deep) 50%, var(--vermilion) 85%);
    filter: drop-shadow(-2px 3px 2px var(--shadow-soft));
    pointer-events: none;
  }
  /* The spread's own corner is on the top leaf (phones) or the right leaf (wider). */
  @media (max-width: 47.99rem) {
    .spread--eared .leaf--a {
      clip-path: polygon(0 0, calc(100% - var(--ear)) 0, 100% var(--ear), 100% 100%, 0 100%);
    }
    .spread--eared .leaf--a::after {
      content: "";
      position: absolute;
      top: 0; right: 0;
      width: var(--ear); height: var(--ear);
      background: linear-gradient(225deg, transparent 50%, var(--vermilion-deep) 50%, var(--vermilion) 85%);
      filter: drop-shadow(-2px 3px 2px var(--shadow-soft));
    }
  }
  @media (min-width: 48rem) {
    .spread--eared .leaf--b {
      clip-path: polygon(0 0, calc(100% - var(--ear)) 0, 100% var(--ear), 100% 100%, 0 100%);
    }
    .spread--eared .leaf--b::after {
      content: "";
      position: absolute;
      top: 0; right: 0;
      width: var(--ear); height: var(--ear);
      background: linear-gradient(225deg, transparent 50%, var(--vermilion-deep) 50%, var(--vermilion) 85%);
      filter: drop-shadow(-2px 3px 2px var(--shadow-soft));
    }
  }

  /* ---- App leaves on the landing page */
  .app-leaf { display: flex; flex-direction: column; }
  .app-leaf .art { width: 100%; max-width: 26rem; margin: -0.5rem auto 1.25rem; }
  .app-leaf h3 {
    font-size: var(--step-4);
    font-weight: 400;
    letter-spacing: -0.02em;
  }
  .app-leaf .kind {
    margin-top: 0.2rem;
    font-family: var(--font-display);
    font-style: italic;
    font-size: var(--step-1);
    color: var(--ink-soft);
  }
  .app-leaf p:not(.kind) { margin-top: 1rem; max-width: 30rem; }
  .app-leaf .more { margin-top: auto; padding-top: 1.25rem; }
  .more a { font-weight: 600; }

  /* ---- Terms list (landing "small print") */
  .notes { display: grid; gap: 0; }
  .note {
    display: grid;
    gap: 0.5rem;
    padding-block: 1.5rem;
    border-top: 1px solid var(--crease-dark);
    box-shadow: inset 0 1px 0 var(--crease-light);
  }
  .note:last-child { border-bottom: 1px solid var(--crease-dark); }
  .note dt {
    font-family: var(--font-display);
    font-size: var(--step-2);
    font-weight: 500;
    line-height: 1.2;
  }
  .note dd { max-width: 38rem; }
  .note dd > * + * { margin-top: 1rem; }
  @media (min-width: 48rem) {
    .note { grid-template-columns: 16rem minmax(0, 1fr); gap: 2rem; padding-block: 1.75rem; }
  }

  /* ---- Store link.
          Without an href it is the "not yet" state: a dashed, fold-here outline.
          Give it an href and it becomes the real button automatically. */
  .store-row { display: flex; flex-wrap: wrap; gap: 0.75rem; }
  .store {
    position: relative;
    display: inline-grid;
    gap: 0.1rem;
    min-width: min(100%, 17rem);
    padding: 0.85rem 1.35rem 0.9rem;
    border: 1.5px dashed var(--ink-soft);
    border-radius: 3px;
    color: var(--ink);
    font-weight: 600;
    line-height: 1.3;
    text-decoration: none;
  }
  .store-app {
    font-family: var(--font-display);
    font-size: var(--step-1);
    font-weight: 500;
  }
  .store-state { font-size: 0.9375rem; font-weight: 500; color: var(--ink-soft); }
  .store[href] {
    border: 0;
    padding: calc(0.85rem + 1.5px) calc(1.35rem + 1.5px) calc(0.9rem + 1.5px);
    background: var(--ink);
    color: var(--paper);
    clip-path: polygon(0 0, calc(100% - 0.9rem) 0, 100% 0.9rem, 100% 100%, 0 100%);
  }
  .store[href] .store-state { color: inherit; }
  .store[href]::after {
    content: "";
    position: absolute;
    top: 0; right: 0;
    width: 0.9rem; height: 0.9rem;
    background: linear-gradient(225deg, transparent 50%, var(--vermilion) 50%);
  }
  .store[href]:hover { text-decoration: none; background: color-mix(in srgb, var(--ink) 88%, var(--vermilion)); }
  .store[href]:focus-visible { clip-path: none; }

  /* ---- Rubber-stamp date */
  .stamp {
    display: inline-block;
    margin-top: 1.75rem;
    padding: 0.45rem 0.85rem 0.4rem;
    border: 2px solid var(--vermilion);
    border-radius: 3px;
    box-shadow: inset 0 0 0 2px var(--paper), inset 0 0 0 3px var(--vermilion);
    color: var(--vermilion-ink);
    font-size: var(--step--1);
    font-weight: 600;
    letter-spacing: 0.01em;
    transform: rotate(-1.5deg);
  }

  /* ---- App hero */
  .app-hero {
    display: grid;
    gap: 1.5rem;
    padding-block: var(--space-l) var(--space-l);
  }
  @media (min-width: 52rem) {
    .app-hero {
      grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
      align-items: center;
      gap: 3rem;
      padding-block: var(--space-xl) var(--space-l);
    }
  }
  .app-title { display: grid; }
  .app-name {
    font-size: var(--step-6);
    line-height: 0.92;
    letter-spacing: -0.035em;
    font-weight: 400;
  }
  .app-subtitle {
    margin-top: 0.6rem;
    font-size: var(--step-3);
    font-style: italic;
    letter-spacing: -0.01em;
    color: var(--ink-soft);
  }
  .app-hero .lede { margin-top: 1.5rem; }
  .app-hero-art { margin-inline: auto; width: 100%; max-width: 34rem; }
  .hero-aside { margin-top: 1.1rem; color: var(--ink-soft); font-size: var(--step--1); }

  /* ---- Feature rows */
  .features { display: grid; }
  .feature {
    display: grid;
    gap: 1.5rem;
    padding-block: var(--space-l);
    border-top: 1px solid var(--crease-dark);
    box-shadow: inset 0 1px 0 var(--crease-light);
  }
  .feature:first-child { border-top: 0; box-shadow: none; padding-top: 0; }
  @media (min-width: 52rem) {
    .feature {
      grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
      gap: clamp(2.5rem, 5vw, 5rem);
      align-items: center;
    }
    .feature:nth-child(even) .feature-art { order: 2; }
  }
  .feature-art {
    display: grid;
    place-items: center;
    min-height: 14rem;
    padding: clamp(1.25rem, 3vw, 2.25rem);
    background: var(--paper-deep);
    border-radius: 3px;
    box-shadow: inset 0 2px 5px var(--shade), inset 0 0 0 1px var(--crease-dark);
  }
  .feature-art svg { width: 100%; max-width: 23rem; }
  .feature-art figcaption {
    margin-top: 1rem;
    font-size: var(--step--1);
    color: var(--ink-soft);
    text-align: center;
  }
  .feature h3 { font-size: var(--step-3); font-weight: 400; letter-spacing: -0.015em; }
  .feature-text p { margin-top: 0.9rem; max-width: var(--measure); }
  .feature-text p + p { margin-top: 0.75rem; }

  /* ---- The share snippet, as pasted */
  .share-note {
    position: relative;
    width: min(100%, 17rem);
    padding: 1.25rem 1.5rem 1.3rem;
    background: var(--paper-lift);
    color: var(--ink);
    box-shadow: 0 1px 1px var(--shadow-soft), 0 10px 18px -8px var(--shadow);
    transform: rotate(-1.2deg);
    font-size: 1.125rem;
    line-height: 1.75;
    --ear: 1.35rem;
  }
  .share-note p { font-variant-numeric: tabular-nums; }
  .share-note .squares { letter-spacing: 0.08em; }

  /* ---- Device spread icons */
  .spread--quiet h3 { font-size: var(--step-2); }
  .spread--quiet .leaf p { margin-top: 0.75rem; max-width: 32rem; }

  /* ---- Pricing */
  .plan h3 { font-size: var(--step-3); font-weight: 400; }
  .plan .plan-sub { margin-top: 0.3rem; color: var(--ink-soft); }
  .plan ul { margin-top: 1.25rem; padding: 0; list-style: none; display: grid; gap: 0.6rem; }
  .plan li { position: relative; padding-left: 1.6rem; }
  .plan li::before {
    /* a tiny folded square as the bullet */
    content: "";
    position: absolute;
    left: 0.1rem;
    top: 0.5em;
    width: 0.7rem;
    height: 0.7rem;
    background:
      linear-gradient(225deg, transparent 50%, var(--vermilion) 50%) top right / 0.3rem 0.3rem no-repeat,
      linear-gradient(225deg, transparent 0.21rem, var(--ink) 0.21rem);
  }
  .prices { margin-top: 1.75rem; display: grid; gap: 0.35rem; }
  .price { display: flex; align-items: baseline; gap: 0.5rem; flex-wrap: wrap; }
  .price dt {
    display: flex;
    flex: 1 1 auto;
    align-items: baseline;
    min-width: 5.5rem;
    font-weight: 600;
  }
  .price dt::after {
    content: "";
    flex: 1;
    margin: 0 0.1rem 0 0.6rem;
    border-bottom: 2px dotted var(--ink-faint);
    transform: translateY(-0.3em);
  }
  .price dd {
    font-family: var(--font-display);
    font-size: var(--step-1);
    font-weight: 500;
    font-variant-numeric: lining-nums tabular-nums;
  }
  .price-note {
    flex-basis: 100%;
    margin-top: -0.2rem;
    color: var(--ink-soft);
    font-size: var(--step--1);
  }
  .fine-print { margin-top: 1.5rem; font-size: var(--step--1); color: var(--ink-soft); max-width: 40rem; }

  /* ---- Get / store CTA band */
  .get {
    background: var(--paper-deep);
    padding-block: var(--space-xl);
    margin-top: var(--space-l);
  }
  .get h2 { font-size: var(--step-5); letter-spacing: -0.022em; line-height: 1; }
  .get p { margin-top: 1rem; max-width: 34rem; }
  .get .store-row { margin-top: 2rem; }
  .get .fine-print { margin-top: 1.25rem; }

  /* ---- Long documents: privacy, terms */
  .doc-head { padding-block: var(--space-l) var(--space-m); }
  .doc-head h1 { font-size: var(--step-5); letter-spacing: -0.022em; line-height: 1; }
  .doc-head .effective { margin-top: 1rem; color: var(--ink-soft); }
  .doc {
    display: grid;
    gap: var(--space-l);
    padding-bottom: var(--space-l);
  }
  @media (min-width: 64rem) {
    .doc { grid-template-columns: 13rem minmax(0, 40rem); gap: 5rem; }
    .toc { position: sticky; top: 1.5rem; align-self: start; }
  }
  .toc h2 {
    font-family: var(--font-body);
    font-size: var(--step--1);
    font-weight: 600;
    letter-spacing: 0;
    color: var(--ink-soft);
  }
  .toc ol { margin-top: 0.5rem; display: grid; gap: 0.1rem; }
  .toc a { display: inline-block; padding-block: 0.25rem; color: var(--ink); font-size: 0.9375rem; text-decoration-color: var(--ink-faint); }
  @media (max-width: 63.99rem) {
    .toc { padding: 1.25rem 1.25rem 1rem; background: var(--paper-deep); border-radius: 3px; }
    .toc ol { grid-template-columns: repeat(auto-fill, minmax(11rem, 1fr)); column-gap: 1rem; }
  }
  .prose { max-width: 40rem; }
  .prose h2 {
    font-size: var(--step-3);
    margin-top: 3rem;
    scroll-margin-top: 1.5rem;
  }
  .prose h2:first-child { margin-top: 0; }
  .prose h3 { margin-top: 2rem; font-size: var(--step-1); font-weight: 600; font-family: var(--font-body); letter-spacing: 0; }
  .prose p, .prose ul, .prose ol { margin-top: 1rem; }
  .prose ul, .prose ol { padding-left: 1.3rem; }
  .prose li + li { margin-top: 0.55rem; }
  .prose li::marker { color: var(--vermilion); }

  .summary {
    position: relative;
    padding: 1.5rem 1.5rem 1.6rem;
    background: var(--paper-deep);
    border-radius: 3px 0 3px 3px;
    --ear: 1.6rem;
  }
  .summary h2 { margin-top: 0; font-size: var(--step-2); }
  .summary p { margin-top: 0.6rem; }

  /* ---- FAQ */
  .faq-group + .faq-group { margin-top: var(--space-l); }
  .faq-group > h2 { font-size: var(--step-3); margin-bottom: 0.75rem; }
  .faq details {
    border-top: 1px solid var(--crease-dark);
    box-shadow: inset 0 1px 0 var(--crease-light);
  }
  .faq details:last-child { border-bottom: 1px solid var(--crease-dark); }
  .faq summary {
    position: relative;
    display: block;
    padding: 1rem 2.75rem 1rem 0;
    font-family: var(--font-display);
    font-size: var(--step-1);
    font-weight: 500;
    line-height: 1.3;
    cursor: pointer;
    list-style: none;
  }
  .faq summary::-webkit-details-marker { display: none; }
  .faq summary::after {
    /* a small square with a folded corner; the fold opens with the answer */
    content: "";
    position: absolute;
    right: 0.4rem;
    top: 50%;
    width: 1rem;
    height: 1rem;
    margin-top: -0.5rem;
    border: 1.5px solid var(--ink);
    background: linear-gradient(225deg, var(--vermilion) 0.3rem, transparent 0.3rem);
  }
  .faq details[open] summary::after {
    background: var(--vermilion);
    border-color: var(--vermilion);
  }
  .faq .answer { padding-bottom: 1.4rem; max-width: 40rem; }
  .faq .answer > * + * { margin-top: 0.8rem; }
  .faq .answer ol, .faq .answer ul { padding-left: 1.3rem; }
  .faq .answer li + li { margin-top: 0.4rem; }

  .contact-card {
    position: relative;
    display: grid;
    gap: 0.4rem;
    padding: 1.5rem 1.5rem 1.6rem;
    background: var(--paper-lift);
    box-shadow: 0 1px 1px var(--shadow-soft), 0 14px 22px -12px var(--shadow);
    --ear: 1.6rem;
  }
  .contact-card .address {
    font-family: var(--font-display);
    font-size: clamp(1.3rem, 1rem + 1.6vw, 2rem);
    line-height: 1.2;
    overflow-wrap: anywhere;
  }
  .contact-card .address a { color: var(--ink); text-decoration-color: var(--vermilion); }
  .contact-card p:not(.address) { color: var(--ink-soft); }

  /* ---- Press */
  .facts { display: grid; gap: 0; margin-top: 1.25rem; }
  .fact {
    display: grid;
    gap: 0.15rem;
    padding-block: 0.7rem;
    border-top: 1px solid var(--crease-dark);
  }
  .fact dt { font-size: var(--step--1); font-weight: 600; color: var(--ink-soft); }
  @media (min-width: 30rem) {
    .fact { grid-template-columns: 7.5rem minmax(0, 1fr); gap: 1rem; }
    .fact dt { font-size: var(--step-0); padding-top: 0.05rem; }
  }
  .spread--quiet .fact dd { max-width: none; }
  .press-app h2 { font-size: var(--step-4); }
  .press-app .kind { font-family: var(--font-display); font-style: italic; color: var(--ink-soft); font-size: var(--step-1); }
  .press-app .blurb { margin-top: 1.25rem; }

  .assets { display: grid; gap: 2rem; }
  @media (min-width: 52rem) {
    .assets { grid-template-columns: 1.4fr 0.8fr 1fr; align-items: start; }
  }
  .asset-group h3 { font-size: var(--step-2); }
  .asset-group > p { margin-top: 0.4rem; color: var(--ink-soft); font-size: var(--step--1); }
  .slots { display: flex; gap: 0.75rem; margin-top: 1rem; }
  .slot {
    flex: 1 1 0;
    display: grid;
    place-items: center;
    min-width: 0;
    padding: 0.5rem;
    border: 1.5px dashed var(--ink-faint);
    border-radius: 3px;
    background: repeating-linear-gradient(-45deg, transparent 0 9px, var(--shade) 9px 10px);
    color: var(--ink-soft);
    font-size: var(--step--1);
    font-weight: 500;
    text-align: center;
  }
  .slot--phone { aspect-ratio: 9 / 19.5; border-radius: 12px; }
  .slot--icon { aspect-ratio: 1; border-radius: 22%; max-width: 7rem; }
  .slot--video { aspect-ratio: 16 / 9; }

  /* ---- 404 */
  .lost { padding-block: var(--space-xl); display: grid; gap: 2rem; }
  @media (min-width: 52rem) {
    .lost { grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr); align-items: center; gap: 4rem; }
  }
  .lost h1 { font-size: var(--step-5); line-height: 1; letter-spacing: -0.022em; }
  .lost p { margin-top: 1.25rem; max-width: 30rem; }
  .lost ul { margin-top: 1.25rem; display: flex; flex-wrap: wrap; gap: 0.25rem 1.25rem; }
  .lost ul a { display: inline-block; padding-block: 0.35rem; font-weight: 600; }
}

/* ------------------------------------------------------------------ art */
@layer art {
  /* Paper grain: an inline SVG feTurbulence filter laid over the whole page. */
  .grain {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    max-width: none;
    z-index: 40;
    pointer-events: none;
    opacity: var(--grain-opacity);
  }
  .grain .night { display: none; }
  @media (prefers-color-scheme: dark) {
    .grain .day { display: none; }
    .grain .night { display: inline; }
  }
  .marker-ink { fill: none; stroke: var(--ink); stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }

  .mark-sheet { fill: var(--sheet); stroke: var(--ink); stroke-width: 1.75; stroke-linejoin: round; }
  .mark-flap { fill: var(--vermilion); stroke: var(--ink); stroke-width: 1.75; stroke-linejoin: round; }

  .art { width: 100%; overflow: visible; }
  .art.device-art { width: 8.5rem; margin-bottom: 1rem; }
  .art .sheet { fill: var(--sheet); stroke: var(--sheet-edge); stroke-width: 1; stroke-linejoin: round; }
  .art .sheet--under { fill: var(--sheet-shade); }
  .art .flap { fill: var(--vermilion); stroke: var(--vermilion-deep); stroke-width: 1; stroke-linejoin: round; }
  .art .flap--shade { fill: var(--vermilion-shade); }
  .art .flap-shadow { fill: none; stroke: var(--shadow); stroke-width: 3; }
  .art .cast-shadow { fill: var(--shadow); }
  .art .crease-dark { fill: none; stroke: var(--sheet-edge); stroke-width: 1; }
  .art .crease-light { fill: none; stroke: var(--crease-light); stroke-width: 1; }
  .art .valley { fill: none; stroke: var(--ink); stroke-width: 1.6; stroke-dasharray: 9 6; }
  .art .arrow { fill: none; stroke: var(--ink); stroke-width: 1.6; stroke-linecap: round; }
  .art .dotted { fill: none; stroke: var(--ink); stroke-width: 2; stroke-dasharray: 0 7; stroke-linecap: round; }
  .art .ink { fill: var(--ink); }
  .art .ink-line { fill: none; stroke: var(--ink); stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
  .art .soft-line { fill: none; stroke: var(--ink-soft); stroke-width: 1.2; stroke-linecap: round; }
  .art .faint { fill: none; stroke: var(--ink-faint); stroke-width: 1.5; }
  .art .ghost-1 { fill: var(--ink); fill-opacity: 0.3; }
  .art .ghost-2 { fill: var(--ink); fill-opacity: 0.15; }
  .art .ball { fill: var(--vermilion); stroke: var(--ink); stroke-width: 1.6; }
  .art .ball--sm { stroke-width: 1.2; }
  .art .ball-shadow { fill: var(--ink); fill-opacity: 0.14; }
  .art .card { fill: var(--sheet); stroke: var(--sheet-edge); }
  .art .label { font-family: var(--font-display); font-style: italic; font-size: 19px; fill: var(--ink-soft); }
  .art .label-sans { font-family: var(--font-body); font-size: 12px; font-weight: 600; fill: var(--ink-soft); }
  .art .tag-text { font-family: var(--font-display); font-size: 21px; font-weight: 500; fill: var(--ink); }
  .art .frame-no { font-family: var(--font-display); font-style: italic; font-size: 15px; fill: var(--ink-soft); }
  .art .tape { fill: var(--vermilion); }
  .art .tape-edge { fill: none; stroke: var(--vermilion-deep); stroke-width: 2; }
  .art .device { fill: none; stroke: var(--ink); stroke-width: 7; stroke-linecap: round; }
  .art .device-outline { fill: var(--sheet); stroke: var(--ink); stroke-width: 2.5; }
  .art .hinge-dot { fill: var(--vermilion); }
  .art .touch { fill: var(--vermilion); fill-opacity: 0.18; stroke: var(--vermilion); stroke-width: 2; }
  .art .snap { fill: var(--ink); fill-opacity: 0.45; }
  .art .target-ring { fill: none; stroke: var(--vermilion); stroke-width: 2; }
  .art .preview { fill: var(--vermilion); fill-opacity: 0.16; stroke: var(--vermilion); stroke-width: 1.6; stroke-dasharray: 5 4; }
  .art .film { fill: #1F1B16; }
  .art .film-hole { fill: #E6DFD3; }
  .art .film-frame { fill: var(--sheet); }
  .art .missed { fill: none; stroke: var(--ink-faint); stroke-width: 1.5; }
  .art .future { fill: none; stroke: var(--ink-faint); stroke-width: 1.5; stroke-dasharray: 3 4; }
  .art .today { fill: none; stroke: var(--vermilion); stroke-width: 2; }
  .art .swatch { stroke: var(--sheet-edge); stroke-width: 1; }
  .art .curl { fill: url(#curl-grad); stroke: var(--sheet-edge); stroke-width: 1; }
  .stop-curl-a { stop-color: var(--sheet-shade); }
  .stop-curl-b { stop-color: var(--sheet); }
  .stop-strip-a { stop-color: #000; stop-opacity: 0.22; }
  .stop-strip-b { stop-color: #000; stop-opacity: 0; }
  .art .valley-sm { fill: none; stroke: var(--ink); stroke-width: 1.4; stroke-dasharray: 5 4; }
  .art .plane-top { fill: var(--sheet); stroke: var(--ink); stroke-width: 1.5; stroke-linejoin: round; }
  .art .plane-under { fill: var(--vermilion); stroke: var(--ink); stroke-width: 1.5; stroke-linejoin: round; }

  /* The strip in the Foldle hero rests mid-fold, showing its vermilion back. */
  .art .strip { transform-box: fill-box; transform-origin: 50% 0; transform: scaleY(-0.62); }
  .art .strip-was { fill: none; stroke: var(--ink-faint); stroke-width: 1.4; stroke-dasharray: 3 5; }
  .art .strip-face { fill: var(--vermilion); stroke: var(--vermilion-deep); stroke-width: 1; }
}

/* --------------------------------------------------------------- motion */
@layer motion {
  @media (prefers-reduced-motion: no-preference) {
    html { scroll-behavior: smooth; }

    /* Landing: the spread opens flat, like unfolding the phone.
       One keyframe set; the start angle comes from a custom property, so crossing the
       breakpoint never swaps animation-name (which would replay the animation). */
    .spread--opening .leaf {
      animation: open-leaf 1.3s cubic-bezier(0.22, 0.7, 0.2, 1) 0.2s backwards;
    }
    .spread--opening .leaf--a { --open-from: rotateX(26deg); transform-origin: 50% 100%; }
    .spread--opening .leaf--b { --open-from: rotateX(-26deg); transform-origin: 50% 0; }
    @media (min-width: 48rem) {
      .spread--opening .leaf--a { --open-from: rotateY(-30deg); transform-origin: 100% 50%; }
      .spread--opening .leaf--b { --open-from: rotateY(30deg); transform-origin: 0 50%; }
    }
    @keyframes open-leaf { from { transform: var(--open-from); filter: brightness(0.92); } }

    /* Foldle: the bottom strip folds up once. The face swaps at the moment it stands on edge. */
    .app-hero .art .strip { animation: fold-strip 1.7s linear 0.5s backwards; }
    .app-hero .art .strip-face { animation: fold-face 1.7s linear 0.5s backwards; }
    .app-hero .art .strip-lift { animation: lift-shadow 1.7s linear 0.5s backwards; }
    @keyframes lift-shadow { 0%, 45% { opacity: 0; } 100% { opacity: 0.35; } }
    @keyframes fold-strip {
      0%   { transform: scaleY(1); animation-timing-function: cubic-bezier(0.55, 0, 0.9, 0.6); }
      50%  { transform: scaleY(0.001); animation-timing-function: steps(1, end); }
      50.1% { transform: scaleY(-0.001); animation-timing-function: cubic-bezier(0.1, 0.45, 0.25, 1); }
      100% { transform: scaleY(-0.62); }
    }
    @keyframes fold-face {
      0%   { fill: var(--sheet); stroke: var(--sheet-edge); }
      49.9% { fill: var(--sheet-shade); stroke: var(--sheet-edge); }
      50%  { fill: var(--vermilion-deep); stroke: var(--vermilion-deep); }
      100% { fill: var(--vermilion); stroke: var(--vermilion-deep); }
    }

    /* Riffle: the top page plays like a flipbook, 8 frames a second, three times. Hover to thumb it again. */
    .app-hero .art .frames { animation: riffle 0.75s steps(6, end) 0.6s 3 backwards; }
    .app-hero .art--riffle:hover .frames { animation: riffle-again 0.75s steps(6, end) infinite; }
    @keyframes riffle { from { transform: translateX(0); } to { transform: translateX(-1368px); } }
    @keyframes riffle-again { from { transform: translateX(0); } to { transform: translateX(-1368px); } }

    .faq summary::after { transition: background-color 0.2s ease, border-color 0.2s ease; }
  }

  @media print {
    .grain, .skip-link { display: none; }
    .site-footer, .get { background: none; }
  }
}

/* Honest launch note under Duo hinge descriptions; remove when the hinge update ships. */
.duo-note {
  margin-top: 0.75rem;
  font-size: 0.875rem;
  color: var(--ink-soft, inherit);
  font-style: italic;
}