/* ToDoTo case study. Same structure as the FutVia and Transita case studies (top bar, chapter
   rail, numbered chapters), in the diegonmtz design system: paper, 1px black lines, square
   corners, pink used sparingly, orange only for the main action. */
:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --ink: #000000;
  --ink-soft: #2f2f2f;
  --line: #000000;
  --pink: #ff0088;
  --pink-text: #d01267;
  --cta: #fa8334;

  /* diegonmtz design system: Cormorant Garamond body, Newsreader headings, Space Mono labels. */
  --font-ui: "Space Mono", ui-monospace, monospace;
  --font-body: "Cormorant Garamond", Georgia, serif;
  --font-serif: "Newsreader", Georgia, serif;

  --rail: 248px;
  --gutter: clamp(16px, 4vw, 56px);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 64px; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 400 1.22rem/1.55 var(--font-body);
}

a { color: inherit; }

img { display: block; max-width: 100%; height: auto; }

/* Top bar */
.top-quick-nav {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}

.top-quick-nav__inner {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
  padding: 10px var(--gutter);
}

.top-quick-nav a {
  padding: 7px 12px;
  border: 1px solid var(--line);
  font: 700 .62rem var(--font-ui);
  letter-spacing: .12em;
  text-decoration: none;
  text-transform: uppercase;
}

.top-quick-nav a:hover,
.top-quick-nav a:focus-visible { background: var(--ink); color: #fff; }
.top-quick-nav a.is-live { background: var(--cta); }
.top-quick-nav a.is-live:hover { background: var(--ink); }

/* Layout */
.page-shell {
  display: grid;
  grid-template-columns: var(--rail) 1fr;
}

.chapter-rail {
  position: sticky;
  top: 49px;
  align-self: start;
  height: calc(100vh - 49px);
  padding: 28px 22px;
  border-right: 1px solid var(--line);
  overflow-y: auto;
}

.rail-brand {
  display: block;
  font: 700 .8rem var(--font-ui);
  letter-spacing: .14em;
  text-decoration: none;
}

.rail-doc {
  margin: 6px 0 26px;
  color: var(--pink-text);
  font: 700 .6rem var(--font-ui);
  letter-spacing: .14em;
  text-transform: uppercase;
}

.chapter-rail nav { display: grid; }

.chapter-rail nav a {
  padding: 7px 0;
  border-top: 1px solid var(--line);
  font: 400 .62rem var(--font-ui);
  letter-spacing: .1em;
  text-decoration: none;
  text-transform: uppercase;
}

.chapter-rail nav a.is-active {
  color: var(--pink-text);
  font-weight: 700;
}

.case-main {
  min-width: 0;
  padding: 0 var(--gutter) 80px;
}

.mobile-index { display: none; }

/* Chapters */
.chapter {
  max-width: 1080px;
  padding: 56px 0;
  border-bottom: 1px solid var(--line);
}

.chapter:last-child { border-bottom: 0; }

.chapter-kicker {
  margin: 0 0 10px;
  color: var(--pink-text);
  font: 700 .62rem var(--font-ui);
  letter-spacing: .14em;
  text-transform: uppercase;
}

.chapter-head { margin-bottom: 28px; }

/* The ToDoTo logo, as in the app: the mark and the wordmark with "Do" reversed. */
.chapter h1.logo {
  display: flex;
  align-items: center;
  gap: .28em;
  margin: 0;
  font: 700 clamp(3.2rem, 8.5vw, 6rem)/1 var(--font-serif);
  letter-spacing: -.045em;
}

.logo-mark {
  width: .9em;
  height: .9em;
  flex: none;
}

.wm-do {
  display: inline-block;
  padding: 0 .08em;
  background: var(--ink);
  color: #fff;
  line-height: .92;
}

.chapter h2 {
  margin: 0;
  font: 400 clamp(2rem, 4.2vw, 3.2rem)/1.08 var(--font-serif);
}

.chapter h1 + .chapter-subtitle {
  max-width: 720px;
  margin-top: 18px;
  font-size: clamp(1.4rem, 2.6vw, 2rem);
  font-style: italic;
}

.chapter h3 {
  margin: 0 0 10px;
  font: 500 1.48rem/1.2 var(--font-serif);
}

.step-label {
  margin: 0 0 8px !important;
  color: var(--pink-text);
  font: 700 .62rem var(--font-ui);
  letter-spacing: .14em;
  text-transform: uppercase;
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin-bottom: 32px;
  border: 1px solid var(--line);
  background: var(--surface);
}

.steps article {
  padding: 20px 22px;
  border-left: 1px solid var(--line);
}

.steps article:first-child { border-left: 0; }

.chapter p { margin: 0 0 14px; }

.chapter ul,
.chapter ol { margin: 0; padding-left: 1.2em; }

.chapter li + li { margin-top: 6px; }

.chapter ul li::marker { color: var(--pink); }

.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}

.two-col + .two-col,
blockquote + .two-col,
.grades + .two-col { margin-top: 28px; }

blockquote {
  margin: 0 0 28px;
  padding: 20px 24px;
  border: 1px solid var(--line);
  border-left: 6px solid var(--pink);
  background: var(--surface);
  font: italic 400 clamp(1.25rem, 2vw, 1.6rem)/1.4 var(--font-serif);
}

.word-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 12px;
}

.word-stack span {
  padding: 6px 10px;
  border: 1px solid var(--line);
  font: 700 .66rem var(--font-ui);
  letter-spacing: .12em;
  text-transform: uppercase;
}

/* Evidence */
.evidence { margin: 0; }

.evidence img {
  width: 100%;
  border: 1px solid var(--line);
  background: var(--surface);
}

.evidence figcaption {
  margin-top: 10px;
  color: var(--ink-soft);
  font-size: 1.08rem;
  line-height: 1.45;
}

.evidence figcaption strong { color: var(--ink); }

.decisions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px 28px;
}

.note {
  margin-top: 28px !important;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font: 400 .66rem/1.7 var(--font-ui);
  letter-spacing: .08em;
  text-transform: uppercase;
}

/* Grades */
.grades {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--line);
  background: var(--surface);
}

.grades div {
  padding: 18px 18px 16px;
  border-left: 1px solid var(--line);
}

.grades div:first-child { border-left: 0; }

.grades strong {
  display: block;
  font: 500 2.4rem/1 var(--font-serif);
}

.grades span,
.grades small {
  display: block;
  margin-top: 8px;
  font: 700 .58rem var(--font-ui);
  letter-spacing: .1em;
  text-transform: uppercase;
}

.grades small { margin-top: 4px; color: var(--ink-soft); font-weight: 400; }

/* Calls to action */
.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.cta {
  padding: 12px 18px;
  border: 1px solid var(--line);
  font: 700 .66rem var(--font-ui);
  letter-spacing: .12em;
  text-decoration: none;
  text-transform: uppercase;
}

.cta-primary { background: var(--cta); box-shadow: 4px 4px 0 var(--ink); }
.cta-primary:hover,
.cta-primary:focus-visible { background: var(--ink); color: #fff; }
.cta-secondary:hover,
.cta-secondary:focus-visible { background: var(--ink); color: #fff; }

a:focus-visible { outline: 2px solid var(--pink); outline-offset: 2px; }

/* Phone */
@media (max-width: 900px) {
  .page-shell { display: block; }
  .chapter-rail { display: none; }

  .mobile-index {
    position: sticky;
    top: 45px;
    z-index: 5;
    display: flex;
    gap: 14px;
    margin: 0 calc(var(--gutter) * -1);
    padding: 10px var(--gutter);
    overflow-x: auto;
    border-bottom: 1px solid var(--line);
    background: var(--bg);
    white-space: nowrap;
  }

  .mobile-index a {
    font: 400 .6rem var(--font-ui);
    letter-spacing: .1em;
    text-decoration: none;
    text-transform: uppercase;
  }

  .mobile-index a.is-active { color: var(--pink-text); font-weight: 700; }

  .top-quick-nav__inner { justify-content: flex-start; overflow-x: auto; }
  .top-quick-nav a { white-space: nowrap; }

  .chapter { padding: 40px 0; }
  .two-col,
  .decisions { grid-template-columns: 1fr; gap: 24px; }
  .grades { grid-template-columns: 1fr 1fr; }
  .steps { grid-template-columns: 1fr; }
  .steps article { border-left: 0; border-top: 1px solid var(--line); }
  .steps article:first-child { border-top: 0; }
  .grades div:nth-child(3) { border-left: 0; }
  .grades div:nth-child(n + 3) { border-top: 1px solid var(--line); }
}