/* =====================================================================
   btc-intel — the showcase layer: the home page, the top bar and the
   stage banner on each console page.

   The cyanotype: one ink (cobalt) on one paper (pale blue), pictures drawn
   as dots by DotArt, and a single orange square that always marks the lead.
   ===================================================================== */

:root {
  --frame: 76rem;
  --gutter: 2rem;
  --pad-x: max(var(--gutter), calc((100% - var(--frame)) / 2));
  --fs-hero: clamp(2.75rem, 1.2rem + 5.4vw, 6.25rem);
  --fs-display-2: clamp(1.875rem, 1.1rem + 2.4vw, 3.25rem);
  --fs-chapter: clamp(1.625rem, 1.1rem + 1.5vw, 2.375rem);
}

@media (max-width: 720px) {
  :root {
    --gutter: 1rem;
  }
}

/* -- shell, top variant ---------------------------------------------- */
.shell.shell-top {
  display: block;
  max-width: none;
  padding: 0;
}

.shell-top > .content {
  min-width: 0;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: var(--sp-5);
  padding: 0.75rem var(--pad-x);
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: var(--bw-hair) solid var(--rule);
}

.topbar .rail-nav {
  flex-direction: row;
  flex-wrap: wrap;
  gap: 0 var(--sp-4);
  margin: 0;
  font-size: var(--fs-small);
}

.topbar .rail-link::before {
  display: none;
}

.topbar .rail-link[aria-current="page"] {
  color: var(--evidence);
}

.topbar .rail-foot {
  flex-direction: row;
  align-items: center;
  margin: 0 0 0 auto;
}

.wordmark {
  font-family: var(--font-display);
  font-weight: 600;
}

@media (max-width: 1000px) {
  .topbar {
    flex-wrap: wrap;
    gap: var(--sp-2) var(--sp-4);
  }
  .topbar .rail-nav {
    order: 3;
    width: 100%;
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: 0.25rem;
  }
  .topbar .rail-link {
    white-space: nowrap;
  }
}

/* -- buttons in the showcase: a mark box, then the words -------------- */
.cta {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  min-height: 2.75rem;
  padding: 0 1.125rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-decoration: none;
  white-space: nowrap;
  transition:
    background-color var(--dur-2) var(--ease-out),
    color var(--dur-2) var(--ease-out);
}

.cta-solid {
  padding-left: 0.25rem;
  background: var(--on-cobalt);
  color: var(--cobalt);
}
.cta-solid:hover {
  background: #fff;
  color: var(--cobalt-deep);
}

.cta-mark {
  display: grid;
  place-items: center;
  width: 2.25rem;
  height: 2.25rem;
  background: var(--cobalt);
}
.cta-mark .wordmark-mark {
  background: var(--on-cobalt);
}

.cta-line {
  --bk: var(--on-cobalt-faint);
  color: var(--on-cobalt);
  background-color: color-mix(in srgb, var(--on-cobalt) 8%, transparent);
}
.cta-line:hover {
  --bk: var(--on-cobalt);
  color: #fff;
  background-color: color-mix(in srgb, var(--on-cobalt) 16%, transparent);
}

/* -- hero ------------------------------------------------------------- */
.hero {
  position: relative;
  overflow: hidden;
  padding: var(--sp-9) 0 0;
  background: var(--cobalt);
  color: var(--on-cobalt);
}

/* The column rails: two hairlines down the frame, as on a drawing sheet. */
.hero::before,
.hero::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  width: 1px;
  background: color-mix(in srgb, var(--on-cobalt) 18%, transparent);
  pointer-events: none;
}
.hero::before {
  left: calc(var(--pad-x) - 1rem);
}
.hero::after {
  right: calc(var(--pad-x) - 1rem);
}

.hero-copy {
  position: relative;
  z-index: 1;
  max-width: 58rem;
  margin-left: var(--pad-x);
  margin-right: var(--gutter);
}

.hero-kicker {
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  color: var(--on-cobalt-soft);
}

.hero-title {
  margin-top: var(--sp-4);
  font-family: var(--font-display);
  font-size: var(--fs-hero);
  font-weight: 500;
  line-height: 0.98;
  letter-spacing: -0.045em;
  color: #fff;
}

.hero-lede {
  max-width: 40rem;
  margin-top: var(--sp-5);
  font-size: 1.125rem;
  line-height: 1.55;
  color: var(--on-cobalt-soft);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
  margin-top: var(--sp-6);
}

.hero-art {
  position: relative;
  margin-top: var(--sp-7);
  color: var(--on-cobalt);
}

.hero-canvas {
  display: block;
  width: 100%;
  aspect-ratio: 368 / 165;
}

/* The moment of attribution: the gap between the two hands. */
.hero-spark {
  position: absolute;
  display: block;
  left: 50%;
  top: 48.5%;
  translate: -50% -50%;
  width: clamp(10px, 1.3vw, 18px);
  aspect-ratio: 1;
  background: var(--flag);
  box-shadow: 0 0 0 6px color-mix(in srgb, var(--flag) 25%, transparent);
  animation: spark 1.6s var(--ease-out) 1.2s both;
}

@keyframes spark {
  0% {
    opacity: 0;
    transform: scale(0.2);
  }
  40% {
    opacity: 1;
    transform: scale(1.6);
  }
  100% {
    opacity: 1;
    transform: none;
  }
}

.hero-ticker {
  position: relative;
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  margin: 0;
  padding: 0 var(--pad-x);
  border-top: 1px solid color-mix(in srgb, var(--on-cobalt) 22%, transparent);
  background: var(--cobalt-deep);
}

.hero-ticker > div {
  padding: var(--sp-4) var(--sp-4) var(--sp-4) 0;
}
.hero-ticker > div + div {
  padding-left: var(--sp-4);
  border-left: 1px solid color-mix(in srgb, var(--on-cobalt) 16%, transparent);
}

.hero-ticker dt {
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.04em;
  color: var(--on-cobalt-faint);
}

.hero-ticker dd {
  margin: 0.25rem 0 0;
  font-family: var(--font-mono);
  font-size: 1.375rem;
  font-variant-numeric: tabular-nums;
  color: #fff;
}

@media (max-width: 720px) {
  .hero {
    padding-top: var(--sp-7);
  }
  .hero-ticker {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .hero-ticker > div,
  .hero-ticker > div + div {
    padding: var(--sp-3) 0;
    border-left: 0;
    border-bottom: 1px solid color-mix(in srgb, var(--on-cobalt) 16%, transparent);
  }
  .hero-ticker > div:last-child {
    border-bottom: 0;
  }
}

/* -- why it holds up --------------------------------------------------- */
.proof-strip {
  padding: var(--sp-8) var(--pad-x);
  border-bottom: var(--bw-hair) solid var(--rule);
}

.proof-strip-title {
  font-family: var(--font-display);
  font-size: var(--fs-display-2);
  font-weight: 500;
  letter-spacing: -0.035em;
}

.proof-strip-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: var(--sp-6);
  border-top: var(--bw-hair) solid var(--ink);
}

.big-proof {
  padding: var(--sp-5) var(--sp-5) var(--sp-5) 0;
}
.big-proof + .big-proof {
  padding-left: var(--sp-5);
  border-left: var(--bw-hair) solid var(--rule);
}

.big-proof-value {
  font-family: var(--font-display);
  font-size: clamp(2rem, 1.3rem + 2.8vw, 4.25rem);
  white-space: nowrap;
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.05em;
  color: var(--evidence);
  font-variant-numeric: tabular-nums;
}

.big-proof-what {
  max-width: 16rem;
  margin-top: var(--sp-3);
  color: var(--ink-soft);
}

.proof-strip-note {
  max-width: 44rem;
  margin-top: var(--sp-5);
  font-size: var(--fs-small);
  color: var(--ink-muted);
}

@media (max-width: 900px) {
  .proof-strip-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .big-proof:nth-child(3) {
    padding-left: 0;
    border-left: 0;
  }
  .big-proof:nth-child(n + 3) {
    border-top: var(--bw-hair) solid var(--rule);
  }
}

/* -- the pipeline ------------------------------------------------------ */
.pipeline {
  padding: var(--sp-9) var(--pad-x) var(--sp-8);
}

.pipeline-head {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
  gap: var(--sp-6);
  align-items: end;
}

.pipeline-head h2 {
  font-family: var(--font-display);
  font-size: var(--fs-display-2);
  font-weight: 500;
  line-height: 1.04;
  letter-spacing: -0.035em;
}

.pipeline-body {
  display: grid;
  grid-template-columns: 11rem minmax(0, 1fr);
  gap: var(--sp-7);
  margin-top: var(--sp-8);
}

/* The index is the pipeline drawn as a line with a station per stage. */
.stage-index {
  position: sticky;
  top: 5.5rem;
  align-self: start;
}

.stage-index ol {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.stage-index ol::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 0.6rem;
  bottom: 0.6rem;
  width: 1px;
  background: var(--rule);
}

.stage-index a {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: var(--sp-2);
  padding: 0.3125rem 0 0.3125rem 1.25rem;
  color: var(--ink-muted);
  font-size: var(--fs-small);
  text-decoration: none;
  transition: color var(--dur-2) var(--ease-out);
}

.stage-index a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 7px;
  height: 7px;
  margin-top: -3.5px;
  background: var(--paper);
  border: 1px solid var(--ink-faint);
  transition:
    background-color var(--dur-2) var(--ease-out),
    border-color var(--dur-2) var(--ease-out);
}

.stage-index a:hover {
  color: var(--ink);
}

.stage-index a[aria-current="step"] {
  color: var(--ink);
}
.stage-index a[aria-current="step"]::before {
  background: var(--flag);
  border-color: var(--flag);
}

.stage-num {
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  font-variant-numeric: tabular-nums;
  color: var(--ink-faint);
}

/* -- chapters ---------------------------------------------------------- */
.chapters {
  display: flex;
  flex-direction: column;
}

.chapter {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--sp-7);
  align-items: center;
  padding: var(--sp-7) 0;
  border-top: var(--bw-hair) solid var(--rule);
  scroll-margin-top: 5rem;
}
.chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.chapter[data-flip] .chapter-art {
  order: 2;
}

.chapter-art {
  position: relative;
  aspect-ratio: 1;
  background: var(--cobalt);
  color: var(--on-cobalt);
  padding: var(--sp-5);
}

.chapter-art canvas {
  display: block;
  width: 100%;
  height: 100%;
}

/* Drawing-sheet annotations in the art's corners. */
.art-note {
  position: absolute;
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  letter-spacing: 0.04em;
  color: var(--on-cobalt-soft);
}
.art-note-tl {
  top: 0.625rem;
  left: 0.75rem;
}
.art-note-br {
  right: 0.75rem;
  bottom: 0.625rem;
}

/* One orange square per picture: the lead. Three positions, rotated by
   chapter, so it never sits in the same place twice in a row. */
.art-flag {
  position: absolute;
  display: block;
  width: 5%;
  aspect-ratio: 1;
  background: var(--flag);
  top: 22%;
  left: 64%;
}
.art-flag[data-at="1"] {
  top: 58%;
  left: 26%;
}
.art-flag[data-at="2"] {
  top: 36%;
  left: 78%;
}

.chapter-stage {
  display: flex;
  align-items: baseline;
  gap: var(--sp-2);
  color: var(--evidence);
  font-size: var(--fs-small);
  font-weight: 500;
}

.chapter-title {
  margin-top: var(--sp-3);
  font-family: var(--font-display);
  font-size: var(--fs-chapter);
  font-weight: 500;
  line-height: 1.08;
  letter-spacing: -0.03em;
}

.chapter-body {
  max-width: 34rem;
  margin-top: var(--sp-4);
  color: var(--ink-soft);
  font-size: 1rem;
}

.chapter-sample {
  max-width: 34rem;
  margin-top: var(--sp-4);
  padding: var(--sp-2) var(--sp-3);
  border-left: 2px solid var(--evidence);
  background: var(--evidence-w7);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  line-height: 1.5;
  color: var(--ink);
}

.proofs {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(9.5rem, 1fr));
  gap: var(--sp-2);
  margin: var(--sp-5) 0 0;
}

.proof {
  --bk: var(--evidence);
  padding: var(--sp-3);
  background-color: var(--surface);
}

.proof-value {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
}

.proof-what {
  margin: var(--sp-2) 0 0;
  font-size: var(--fs-small);
  line-height: 1.4;
  color: var(--ink-muted);
}

.chapter-foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-4);
  margin-top: var(--sp-5);
}

.condition {
  padding: 0.0625rem 0.375rem;
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  color: var(--caution);
  background: var(--caution-bg);
}

.chapter-link {
  font-weight: 500;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

@media (max-width: 1000px) {
  .pipeline-body {
    grid-template-columns: minmax(0, 1fr);
  }
  .stage-index {
    display: none;
  }
}

@media (max-width: 760px) {
  .pipeline-head,
  .chapter {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--sp-5);
  }
  .chapter[data-flip] .chapter-art {
    order: 0;
  }
  .chapter-art {
    aspect-ratio: 4 / 3;
  }
}

/* -- what it refuses to claim ------------------------------------------ */
.honesty {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: var(--sp-8);
  padding: var(--sp-9) var(--pad-x);
  background: var(--navy);
  color: var(--on-cobalt);
}

.honesty-art {
  position: relative;
  min-height: 30rem;
  color: var(--on-cobalt-faint);
}
.honesty-art canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}
.honesty-art .art-note {
  color: var(--on-cobalt-faint);
}

.honesty-copy h2 {
  font-family: var(--font-display);
  font-size: var(--fs-display-2);
  font-weight: 500;
  line-height: 1.04;
  letter-spacing: -0.035em;
  color: #fff;
}

.honesty-lede {
  max-width: 36rem;
  margin-top: var(--sp-4);
  font-size: 1.0625rem;
  color: var(--on-cobalt-soft);
}

.findings {
  margin-top: var(--sp-6);
  border-top: 1px solid color-mix(in srgb, var(--on-cobalt) 22%, transparent);
}

.finding {
  display: grid;
  grid-template-columns: minmax(0, 14rem) minmax(0, 1fr);
  gap: var(--sp-5);
  padding: var(--sp-5) 0;
  border-bottom: 1px solid color-mix(in srgb, var(--on-cobalt) 22%, transparent);
}

.finding h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: #fff;
}

.finding p {
  color: var(--on-cobalt-soft);
  font-size: var(--fs-body);
}

@media (max-width: 900px) {
  .honesty {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--sp-6);
  }
  .honesty-art {
    min-height: 18rem;
  }
  .finding {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--sp-2);
  }
}

/* -- outro --------------------------------------------------------------- */
.outro {
  position: relative;
  overflow: hidden;
  padding: var(--sp-9) var(--pad-x);
  background: var(--cobalt);
  color: var(--on-cobalt);
}

.outro-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  color: color-mix(in srgb, var(--on-cobalt) 30%, transparent);
}

.outro-copy {
  position: relative;
  max-width: 40rem;
}

.outro-copy h2 {
  font-family: var(--font-display);
  font-size: var(--fs-display-2);
  font-weight: 500;
  letter-spacing: -0.035em;
  color: #fff;
}

.outro-copy p {
  margin-top: var(--sp-3);
  font-size: 1.0625rem;
  color: var(--on-cobalt-soft);
}

/* -- stage banner on console pages -------------------------------------- */
.stage-banner {
  display: grid;
  grid-template-columns: 7.5rem minmax(0, 1fr);
  margin-bottom: var(--sp-6);
  background: var(--cobalt);
  color: var(--on-cobalt);
  text-decoration: none;
  overflow: hidden;
}
.stage-banner:hover {
  color: var(--on-cobalt);
  background: var(--cobalt-deep);
}

.stage-banner-art {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 5.5rem;
  background: var(--cobalt-deep);
  color: var(--on-cobalt-soft);
}

.stage-banner-copy {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  align-content: center;
  gap: 0.25rem var(--sp-3);
  padding: var(--sp-3) var(--sp-5);
}

.stage-banner .stage-num {
  width: 100%;
  color: var(--on-cobalt-faint);
}

.stage-banner-name {
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 500;
  letter-spacing: -0.02em;
  color: #fff;
}

.stage-banner-title {
  color: var(--on-cobalt-soft);
}

/* -- headings across the console get the display face ------------------- */
h1 {
  font-family: var(--font-display);
  font-weight: 500;
  letter-spacing: -0.025em;
}