/*
 * Survey landing pages. Colours and faces come from the survey's theme file as --ls-* tokens;
 * this file holds none of its own, so a second survey needs only a new theme.
 * No web fonts and no third-party requests: the page must work without a consent banner.
 */
*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--ls-ground);
  color: var(--ls-ink);
  font-family: var(--ls-font-body);
  font-size: 1.0625rem;
  line-height: 1.6;
}

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

a { color: var(--ls-accent-strong); text-underline-offset: 0.18em; }
a:hover { color: var(--ls-ink); }

:focus-visible { outline: 3px solid var(--ls-signal); outline-offset: 3px; border-radius: 2px; }

.vh {
  position: absolute !important;
  width: 1px; height: 1px;
  overflow: hidden; clip: rect(0 0 0 0); clip-path: inset(50%);
  white-space: nowrap;
}

.hp { position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden; }

.skip {
  position: absolute; left: 1rem; top: -4rem; z-index: 10;
  padding: 0.5rem 1rem;
  background: var(--ls-surface); color: var(--ls-ink);
}
.skip:focus { top: 1rem; }

.wrap { width: 100%; max-width: 72rem; margin-inline: auto; padding-inline: clamp(1rem, 4vw, 2.5rem); }

h1, h2, h3 { font-family: var(--ls-font-display); font-weight: 600; line-height: 1.15; margin: 0; text-wrap: balance; }
h1 { font-size: clamp(2.3rem, 5.2vw, 3.9rem); letter-spacing: -0.015em; }
h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); letter-spacing: -0.01em; }
h3 { font-size: 1.2rem; }
p { margin: 0; }

/* --- Masthead ----------------------------------------------------------------------------- */

.masthead { border-bottom: 1px solid var(--ls-line); background: var(--ls-surface); }
.masthead-inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem; min-height: 4rem; }

.wordmark { display: inline-flex; align-items: stretch; text-decoration: none; color: var(--ls-ink); }
.wordmark-mark {
  display: inline-flex; align-items: center;
  padding: 0.3rem 0.55rem 0.25rem;
  background: var(--ls-accent); color: var(--ls-accent-ink);
  border-bottom: 4px solid var(--ls-accent-strong);
  font-family: var(--ls-font-body); font-weight: 800; letter-spacing: 0.06em; font-size: 1.05rem;
}
.wordmark-sub {
  display: inline-flex; align-items: center;
  padding-inline: 0.6rem;
  font-family: var(--ls-font-mono); font-size: 0.78rem; letter-spacing: 0.04em; color: var(--ls-muted);
}

.langs { display: flex; gap: 0.25rem; font-family: var(--ls-font-mono); font-size: 0.85rem; }
.langs a {
  padding: 0.35rem 0.6rem; border-radius: 999px;
  color: var(--ls-muted); text-decoration: none;
}
.langs a:hover { color: var(--ls-ink); background: var(--ls-tint); }
.langs a[aria-current] { color: var(--ls-ink); background: var(--ls-tint); font-weight: 700; }

/* --- Hero --------------------------------------------------------------------------------- */

.hero { padding-block: clamp(2.5rem, 7vw, 5.5rem) clamp(3rem, 7vw, 5rem); background: var(--ls-surface); }
.hero-grid { display: grid; gap: clamp(2.5rem, 5vw, 4rem); align-items: center; }
@media (min-width: 62rem) {
  .hero-grid { grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); }
}

.eyebrow {
  font-family: var(--ls-font-mono); font-size: 0.8rem; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--ls-accent-strong); margin-bottom: 1.1rem;
}
.lede { margin-top: 1.4rem; font-size: 1.15rem; color: var(--ls-muted); max-width: 38rem; }

.start { margin-top: 2rem; }
.button {
  display: inline-flex; align-items: center; gap: 0.75rem;
  min-height: 3.25rem; padding: 0.8rem 1.4rem;
  border: 0; border-radius: 0.4rem;
  background: var(--ls-accent-strong); color: var(--ls-accent-ink);
  font: inherit; font-weight: 700; font-size: 1.05rem;
  cursor: pointer;
  box-shadow: 0 4px 0 var(--ls-deep);
  transition: transform 120ms ease, box-shadow 120ms ease, background-color 120ms ease;
}
.button:hover { background: var(--ls-deep); }
.button:active { transform: translateY(3px); box-shadow: 0 1px 0 var(--ls-deep); }
.button-arrow { transition: transform 160ms ease; }
.button:hover .button-arrow { transform: translateX(3px); }

.facts {
  display: flex; flex-wrap: wrap; gap: 0.4rem 1.25rem;
  margin: 1.25rem 0 0; padding: 0; list-style: none;
  font-size: 0.92rem; color: var(--ls-muted);
}
.facts li { display: inline-flex; align-items: center; gap: 0.45rem; }
.facts li::before { content: ""; width: 0.5rem; height: 0.5rem; background: var(--ls-accent); }

.notice {
  margin-top: 1.5rem; padding: 0.75rem 1rem;
  border-left: 4px solid var(--ls-signal); background: var(--ls-signal-soft);
}

/* --- Model matrix: the page's signature ---------------------------------------------------- */

.figure { margin: 0; min-width: 0; }
.figure-frame {
  padding: clamp(1rem, 2.5vw, 1.5rem);
  background: var(--ls-ground);
  border: 1px solid var(--ls-line);
  border-radius: 0.6rem;
  overflow-x: auto;
}
.figure-title {
  margin-bottom: 0.85rem;
  font-family: var(--ls-font-mono); font-size: 0.78rem; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--ls-muted);
}
.figure figcaption { margin-top: 0.85rem; font-size: 0.9rem; color: var(--ls-muted); max-width: 40rem; }

.matrix { width: 100%; border-collapse: separate; border-spacing: 3px; table-layout: fixed; }
.matrix th { font-weight: 400; }
.matrix thead th {
  padding-bottom: 0.3rem;
  font-family: var(--ls-font-mono); font-size: 0.78rem; color: var(--ls-muted); text-align: center;
}
.matrix abbr { text-decoration: none; }
.matrix-corner { width: 40%; }
.matrix tbody th {
  padding-right: 0.5rem;
  text-align: right; font-size: 0.76rem; line-height: 1.15; color: var(--ls-ink);
  text-wrap: balance;
}
.matrix-num { display: none; font-family: var(--ls-font-mono); }

.cell { height: 1.55rem; border-radius: 3px; background: var(--ls-cell-empty); opacity: 0.55; }
.cell-on {
  opacity: 1;
  /* Later levels are drawn stronger: the colour itself reads as progression from A to H. */
  background: color-mix(in srgb, var(--ls-accent-strong) calc(35% + var(--level) * 9%), var(--ls-accent));
  animation: rise 520ms cubic-bezier(0.2, 0.7, 0.2, 1) both;
  animation-delay: calc(var(--level) * 70ms + 150ms);
}
.matrix tbody tr:hover .cell-on { background: var(--ls-deep); }
.matrix tbody tr:hover th { color: var(--ls-accent-strong); }

@keyframes rise {
  from { opacity: 0; transform: translateY(6px) scaleY(0.6); }
  to { opacity: 1; transform: none; }
}

@media (max-width: 34rem) {
  .matrix-corner { width: 2rem; }
  .matrix tbody th { text-align: center; padding-right: 0.25rem; }
  .matrix-num { display: inline; }
  .matrix-name { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .cell { height: 1.35rem; }
}

/* --- Bands ---------------------------------------------------------------------------------- */

.band { padding-block: clamp(3rem, 7vw, 5.5rem); }
.band-tint { background: var(--ls-tint); }
.band h2 { margin-bottom: 1.75rem; }

.benefits { display: grid; gap: 1.25rem; }
@media (min-width: 48rem) { .benefits { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
.benefit {
  padding: 1.5rem;
  background: var(--ls-surface);
  border-top: 4px solid var(--ls-accent);
  border-radius: 0 0 0.5rem 0.5rem;
}
.benefit h3 { margin-bottom: 0.6rem; }
.benefit p { color: var(--ls-muted); }

.split { display: grid; gap: 2rem; }
@media (min-width: 56rem) {
  .split { grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr); align-items: start; }
  .split-wide { grid-template-columns: minmax(0, 1fr) minmax(0, 1.25fr); align-items: center; }
}
.split-head h2 { margin-bottom: 1rem; }
.split-head > p { color: var(--ls-muted); }

/* The pages really are answered in this order, which is why the list is numbered. */
.steps { margin: 0; padding: 0; list-style: none; counter-reset: step; }
.step {
  position: relative;
  padding: 0 0 1.6rem 3.5rem;
  counter-increment: step;
}
.step::before {
  content: counter(step);
  position: absolute; left: 0; top: -0.1rem;
  display: grid; place-items: center;
  width: 2.2rem; height: 2.2rem;
  border-radius: 50%;
  background: var(--ls-surface); border: 2px solid var(--ls-accent);
  font-family: var(--ls-font-mono); font-size: 0.9rem; font-weight: 700; color: var(--ls-accent-strong);
}
.step::after {
  content: "";
  position: absolute; left: calc(1.1rem - 1px); top: 2.3rem; bottom: 0.2rem;
  width: 2px; background: var(--ls-line);
}
.step:last-child { padding-bottom: 0; }
.step:last-child::after { display: none; }
.step:last-child::before { background: var(--ls-accent-strong); border-color: var(--ls-accent-strong); color: var(--ls-accent-ink); }
.step h3 { margin-bottom: 0.3rem; }
.step p { color: var(--ls-muted); }

.sample {
  display: block;
  border-radius: 0.6rem;
  border: 1px solid var(--ls-line);
  background: var(--ls-surface);
  box-shadow: 0 1.5rem 3rem -1.5rem rgb(14 42 40 / 0.35);
}

.disclaimer {
  display: flex; gap: 0.75rem;
  margin-top: 1.75rem; padding: 1rem 1.1rem;
  background: var(--ls-signal-soft);
  border-left: 4px solid var(--ls-signal);
  font-size: 0.92rem;
  scroll-margin-top: 2rem;
}
.disclaimer:target { outline: 3px solid var(--ls-signal); outline-offset: 2px; }
.disclaimer-mark { font-family: var(--ls-font-display); font-size: 1.5rem; line-height: 1; color: var(--ls-signal); font-weight: 700; }

.claim-mark {
  margin-left: 0.15rem;
  font-family: var(--ls-font-display); font-weight: 700;
  color: var(--ls-signal); text-decoration: none;
  vertical-align: super; font-size: 0.75em; line-height: 0;
}
.claim-mark:hover { color: var(--ls-ink); }

.prose { max-width: 48rem; }
.prose p + p { margin-top: 1rem; }

.faq { border-top: 1px solid var(--ls-line); }
.faq details { border-bottom: 1px solid var(--ls-line); }
.faq summary {
  display: flex; justify-content: space-between; gap: 1rem;
  padding: 1.1rem 0;
  cursor: pointer; list-style: none;
  font-family: var(--ls-font-display); font-size: 1.15rem; font-weight: 600;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  flex: none;
  font-family: var(--ls-font-mono); font-size: 1.3rem; line-height: 1.2; color: var(--ls-accent-strong);
}
.faq details[open] summary::after { content: "–"; }
.faq details p { padding-bottom: 1.2rem; color: var(--ls-muted); max-width: 42rem; }

/* --- Closer and colophon -------------------------------------------------------------------- */

.closer { background: var(--ls-deep); color: var(--ls-deep-ink); padding-block: clamp(3rem, 6vw, 4.5rem); }
.closer-inner { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 1.5rem 3rem; }
.closer h2 { color: #fff; }
.closer p { margin-top: 0.5rem; }
.closer .start { margin-top: 0; }
.closer .button { background: var(--ls-accent); color: var(--ls-deep); box-shadow: 0 4px 0 var(--ls-accent-strong); }
.closer .button:hover { background: #fff; }

.colophon { padding-block: 2rem 2.5rem; font-size: 0.9rem; color: var(--ls-muted); }
.colophon-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 1rem 2rem; }
.powered { max-width: 30rem; }
.powered a { font-weight: 700; }
.powered-note { display: block; margin-top: 0.2rem; }
.legal { display: flex; flex-wrap: wrap; gap: 0.5rem 1.25rem; margin: 0; padding: 0; list-style: none; }
.legal a { color: var(--ls-muted); }
.legal a:hover { color: var(--ls-ink); }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}