@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&family=IBM+Plex+Sans:wght@400;500;600;700&display=swap");

/* =========================================================================
   THE SPECIMEN — styles.css
   Example Domain, treated as a museum artifact.
   The artifact keeps its defaults. The commentary is the design.
   ========================================================================= */

/* -------------------------------------------------------------------------
   01 — TOKENS
   ------------------------------------------------------------------------- */
:root {
  /* --- Palette (rationed) --------------------------------------------- */
  --void:          #101418;  /* chrome — everything outside the specimen   */
  --void-soft:     #141A20;  /* aperture panel, one step above void        */
  --void-grain:    #1A2029;  /* noise layer on the void only               */
  --canvas:        #EEEEEE;  /* the specimen surface. Sacred. Never tinted */
  --ink:           #111111;  /* specimen heading + body                    */
  --muted-ink:     #555555;  /* secondary tone on light surfaces           */
  --link:          #334488;  /* the one true brand color                   */
  --link-soft:     rgba(51, 68, 136, 0.35);
  --fiducial:      #FF3EA5;  /* printer's registration mark. Rationed.     */
  --hairline:      #1F2733;  /* 1px voids between things                   */
  --elev-shadow:   #0A0D11;  /* hard offset shadow ink                     */
  --ink-soft:      rgba(238, 238, 238, 0.72); /* canvas, knocked back        */
  --ink-faint:     rgba(238, 238, 238, 0.46);
  --ink-ghost:     rgba(238, 238, 238, 0.18);

  /* --- Type ------------------------------------------------------------ */
  --font-sans: "IBM Plex Sans", system-ui, -apple-system, BlinkMacSystemFont,
               "Segoe UI", Helvetica, Arial, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo,
               Consolas, "Liberation Mono", monospace;
  --font-specimen: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
                   Helvetica, Arial, sans-serif;

  /* Perfect fourth, 1.333, root 1rem = 16px */
  --fs-mega:    5.611rem;  /*  89.8 */
  --fs-display: 4.209rem;  /*  67.3 */
  --fs-h2:      3.157rem;  /*  50.5 */
  --fs-h3:      2.369rem;  /*  37.9 */
  --fs-h4:      1.777rem;  /*  28.4 */
  --fs-lead:    1.333rem;  /*  21.3 */
  --fs-body:    1rem;      /*  16.0 */
  --fs-small:   0.75rem;   /*  12.0 */
  --fs-micro:   0.625rem;  /*  10.0 */

  --lh-tight:   1.1;
  --lh-snug:    1.15;
  --lh-prose:   1.6;
  --lh-body:    1.5;

  --track-mega:    -0.04em;
  --track-display: -0.03em;
  --track-mono:     0.08em;
  --track-micro:    0.14em;

  /* --- Measure ---------------------------------------------------------- */
  --measure:      58ch;
  --measure-cap:  34ch;
  --specimen-w:   600px;

  /* --- 8pt spacing scale ------------------------------------------------ */
  --sp-0:  0;
  --sp-1:  0.5rem;   /*   8 */
  --sp-2:  1rem;     /*  16 */
  --sp-3:  1.5rem;   /*  24 */
  --sp-4:  2rem;     /*  32 */
  --sp-5:  2.5rem;   /*  40 */
  --sp-6:  3rem;     /*  48 */
  --sp-8:  4rem;     /*  64 */
  --sp-10: 5rem;     /*  80 */
  --sp-12: 6rem;     /*  96 */
  --sp-16: 8rem;     /* 128 */
  --sp-24: 12rem;    /* 192 */

  /* --- Elevation: hard offsets, never blur ------------------------------ */
  --elev-0: none;
  --elev-1: 0 0 0 1px var(--hairline);
  --elev-2: 6px 6px 0 0 var(--elev-shadow), 0 0 0 1px var(--hairline);
  --elev-3: 12px 12px 0 0 var(--elev-shadow), 0 0 0 1px var(--fiducial);

  /* --- Motion ----------------------------------------------------------- */
  --ease-out: cubic-bezier(0.2, 0.7, 0.2, 1);
  --dur-fast: 0.18s;
  --dur:      0.4s;
  --dur-slow: 0.6s;
}

/* -------------------------------------------------------------------------
   02 — RESET
   ------------------------------------------------------------------------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background-color: var(--void);
  color: var(--canvas);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: var(--lh-prose);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

::-moz-selection { background: var(--fiducial); color: var(--void); }
::selection      { background: var(--fiducial); color: var(--void); }

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

/* -------------------------------------------------------------------------
   03 — PAGE SHELL + VOID GRAIN
   ------------------------------------------------------------------------- */
.page {
  position: relative;
  min-height: 100vh;
  overflow-x: clip;
  background-color: var(--void);
  color: var(--canvas);
  isolation: isolate;
}

/* Grain lives on the void ONLY. The specimen gets none. */
.void-grain {
  position: fixed;
  inset: -8%;
  z-index: 0;
  pointer-events: none;
  opacity: 0.06;
  mix-blend-mode: overlay;
  background-color: transparent;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='220' height='220' filter='url(%23g)'/%3E%3C/svg%3E");
  background-size: 220px 220px;
  background-repeat: repeat;
}

/* -------------------------------------------------------------------------
   04 — UTILITIES
   ------------------------------------------------------------------------- */
.visually-hidden {
  position: absolute !important;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: var(--sp-1);
  left: var(--sp-1);
  z-index: 100;
  padding: var(--sp-1) var(--sp-2);
  background-color: var(--canvas);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: var(--track-mono);
  text-transform: uppercase;
  text-decoration: none;
  transform: translateY(-200%);
  transition: transform var(--dur-fast) var(--ease-out);
}

.skip-link:focus {
  transform: translateY(0);
}

/* Monospace register — used for all annotation chrome */
.mono {
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: var(--track-mono);
  line-height: 1.4;
  text-transform: uppercase;
}

.mono--label {
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: var(--track-mono);
  text-transform: uppercase;
  color: var(--ink-faint);
}

.mono--micro {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 500;
  letter-spacing: var(--track-micro);
  line-height: 1;
  text-transform: uppercase;
  color: var(--ink-faint);
}

/* -------------------------------------------------------------------------
   05 — MASTHEAD
   ------------------------------------------------------------------------- */
.masthead {
  position: relative;
  z-index: 3;
  padding: var(--sp-8) var(--sp-3) var(--sp-6);
  border-bottom: 1px solid var(--hairline);
  background-image: linear-gradient(
    180deg,
    rgba(16, 20, 24, 0.96) 0%,
    rgba(16, 20, 24, 0.72) 60%,
    rgba(16, 20, 24, 0.96) 100%
  );
}

.masthead__inner {
  display: grid;
  gap: var(--sp-2);
  width: 100%;
  max-width: 1240px;
  margin-inline: auto;
}

/* id strip: mono, uppercase, one magenta fiducial dot */
.masthead__id {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-1);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 500;
  letter-spacing: var(--track-micro);
  text-transform: uppercase;
  color: var(--ink-faint);
}

.masthead__id::before {
  content: "";
  flex: 0 0 auto;
  width: 7px;
  height: 7px;
  background-color: var(--fiducial);
}

.masthead__sep {
  display: inline-block;
  width: 18px;
  height: 1px;
  margin-inline: var(--sp-1);
  background-color: currentColor;
  opacity: 0.5;
  transform: translateY(-0.32em);
}

/* Oversized "example" — cropped by the column, masked at the descender */
.masthead__title {
  margin: 0;
  font-family: var(--font-sans);
  font-size: clamp(3rem, 13.5vw, var(--fs-mega));
  font-weight: 700;
  line-height: 0.92;
  letter-spacing: var(--track-mega);
  text-transform: lowercase;
  color: var(--canvas);
  text-wrap: balance;
  -webkit-mask-image: linear-gradient(180deg, #000 0%, #000 64%, rgba(0, 0, 0, 0.12) 100%);
  mask-image: linear-gradient(180deg, #000 0%, #000 64%, rgba(0, 0, 0, 0.12) 100%);
}

.masthead__subtitle {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: var(--track-micro);
  text-transform: uppercase;
  color: var(--ink-faint);
}

.masthead__lede {
  margin: var(--sp-1) 0 0;
  max-width: var(--measure);
  font-family: var(--font-sans);
  font-size: var(--fs-lead);
  font-weight: 400;
  line-height: var(--lh-prose);
  color: var(--ink-soft);
}

.masthead__nav {
  margin-top: var(--sp-4);
  padding-top: var(--sp-3);
  border-top: 1px solid var(--hairline);
}

/* Chapter nav — the only navigation. Mono, numbered, scrollable. */
.chapternav,
.chapternav > ul,
.chapternav > ol {
  display: flex;
  flex-wrap: nowrap;
  align-items: center;
  gap: var(--sp-3);
  margin: 0;
  padding: 0;
  list-style: none;
}

.chapternav {
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scrollbar-width: thin;
  scrollbar-color: var(--hairline) transparent;
  -webkit-overflow-scrolling: touch;
}

.chapternav::-webkit-scrollbar { height: 4px; }
.chapternav::-webkit-scrollbar-track { background: transparent; }
.chapternav::-webkit-scrollbar-thumb { background: var(--hairline); }

.chapternav li { flex: 0 0 auto; }

.chapternav a {
  display: inline-block;
  padding-block: var(--sp-1);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: var(--track-mono);
  text-transform: uppercase;
  text-decoration: none;
  white-space: nowrap;
  color: var(--ink-faint);
  border-top: 2px solid transparent;
  transition: color var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out);
}

.chapternav a:hover,
.chapternav a:focus-visible {
  color: var(--canvas);
  border-top-color: var(--fiducial);
}

/* -------------------------------------------------------------------------
   06 — NARRATIVE (the void aperture + the two columns)
   ------------------------------------------------------------------------- */
.narrative {
  position: relative;
  z-index: 1;
  display: grid;
  gap: var(--sp-8);
  padding: var(--sp-8) var(--sp-3) var(--sp-12);
}

/* The void is an aperture, not a background. Chamfered clip-path + edge mask. */
.narrative::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-color: var(--void-soft);
  opacity: 0.55;
  clip-path: polygon(
    0 0,
    calc(100% - 56px) 0,
    100% 56px,
    100% 100%,
    56px 100%,
    0 calc(100% - 56px)
  );
  -webkit-mask-image: linear-gradient(180deg, transparent 0%, #000 10%, #000 90%, transparent 100%);
  mask-image: linear-gradient(180deg, transparent 0%, #000 10%, #000 90%, transparent 100%);
}

/* --- Specimen column: pinned -------------------------------------------------- */
.narrative__specimen {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
  min-width: 0;
}

.narrative__chapters {
  position: relative;
  z-index: 3;
  display: grid;
  gap: var(--sp-12);
  min-width: 0;
}

/* -------------------------------------------------------------------------
   07 — THE SPECIMEN
   ------------------------------------------------------------------------- */
.specimen {
  position: relative;
  width: 100%;
  max-width: var(--specimen-w);
  margin-inline: auto;
  isolation: isolate;
}

/* Ghost code + browser chrome scrolling past behind the artifact */
.specimen__ghosts {
  position: absolute;
  inset: -14% -16%;
  z-index: -1;
  display: block;
  pointer-events: none;
  opacity: 0.5;
  mix-blend-mode: screen;
  -webkit-mask-image: linear-gradient(180deg, transparent 0%, #000 16%, #000 84%, transparent 100%);
  mask-image: linear-gradient(180deg, transparent 0%, #000 16%, #000 84%, transparent 100%);
}

/* duotone scrim over the ghost layer */
.specimen__ghosts::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(
    170deg,
    rgba(51, 68, 136, 0.34) 0%,
    rgba(255, 62, 165, 0.06) 58%,
    rgba(16, 20, 24, 0) 100%
  );
  mix-blend-mode: color;
}

.ghost {
  position: absolute;
  max-width: 30ch;
  padding-left: var(--sp-1);
  border-left: 1px solid var(--link-soft);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 400;
  line-height: 1.8;
  letter-spacing: 0.06em;
  white-space: pre;
  color: var(--ink-ghost);
}

.ghost--1 { top: -8%;  left: -10%; transform: rotate(-1.4deg); }
.ghost--2 { top: 16%;  right: -12%; transform: rotate(0.8deg); text-align: right;
            border-left: 0; border-right: 1px solid var(--link-soft);
            padding-left: 0; padding-right: var(--sp-1); }
.ghost--3 { top: 48%;  left: -14%; transform: rotate(0.4deg); }
.ghost--4 { top: 68%;  right: -9%;  transform: rotate(-0.7deg); text-align: right;
            border-left: 0; border-right: 1px solid var(--link-soft);
            padding-left: 0; padding-right: var(--sp-1); }
.ghost--5 { bottom: -6%; left: -6%; transform: rotate(0.9deg); }

.ghost--chrome {
  bottom: 14%;
  right: -14%;
  width: 260px;
  max-width: none;
  padding: var(--sp-1) var(--sp-1) var(--sp-2);
  border: 1px solid rgba(238, 238, 238, 0.12);
  border-left: 1px solid rgba(238, 238, 238, 0.12);
  border-radius: 8px;
  background-color: rgba(238, 238, 238, 0.035);
  transform: rotate(-0.4deg);
  filter: grayscale(1) contrast(1.2);
}

.ghost__dot {
  display: inline-block;
  width: 7px;
  height: 7px;
  margin-right: 5px;
  border-radius: 50%;
  background-color: rgba(238, 238, 238, 0.28);
}

.ghost__url {
  display: block;
  margin-top: var(--sp-1);
  padding-top: var(--sp-1);
  border-top: 1px solid rgba(238, 238, 238, 0.1);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.06em;
  color: rgba(238, 238, 238, 0.34);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Measurement ticks */
.specimen__ticks {
  position: absolute;
  inset: calc(var(--sp-3) * -1);
  z-index: 3;
  display: none;
  pointer-events: none;
  color: var(--ink-faint);
}

.tick {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-1);
  color: inherit;
}

.tick .mono--micro {
  position: relative;
  z-index: 1;
  padding-inline: var(--sp-1);
  background-color: var(--void);
  color: var(--ink-faint);
  white-space: nowrap;
}

.tick::before {
  content: "";
  position: absolute;
  background-color: currentColor;
  opacity: 0.32;
}

.tick--top,
.tick--bottom {
  left: 0;
  right: 0;
  height: 1px;
}

.tick--top    { top: 0; }
.tick--bottom { bottom: 0; }

.tick--top::before,
.tick--bottom::before {
  left: 0;
  right: 0;
  height: 1px;
  top: 50%;
}

.tick--left,
.tick--right {
  top: 0;
  bottom: 0;
  width: 1px;
}

.tick--left  { left: 0; }
.tick--right { right: 0; }

.tick--left::before,
.tick--right::before {
  top: 0;
  bottom: 0;
  width: 1px;
  left: 50%;
}

.tick--left .mono--micro,
.tick--right .mono--micro {
  writing-mode: vertical-rl;
  padding-block: var(--sp-1);
  padding-inline: 0;
}

.tick--left .mono--micro { transform: rotate(180deg); }

/* Stage: every card occupies the same cell; the artifact is re-set live */
.specimen__stage {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-areas: "stack";
  min-height: 320px;
}

.specimen__stage > * { grid-area: stack; }

.specimen__state {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2) var(--sp-3);
  padding-top: var(--sp-3);
  border-top: 1px solid var(--hairline);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 500;
  letter-spacing: var(--track-micro);
  text-transform: uppercase;
  color: var(--ink-faint);
}

.specimen__state > * {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.specimen__state > *::before {
  content: "";
  width: 6px;
  height: 6px;
  border: 1px solid currentColor;
  background-color: transparent;
  transition: background-color var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out);
}

.specimen__state .is-active {
  color: var(--canvas);
}

.specimen__state .is-active::before {
  background-color: var(--fiducial);
  border-color: var(--fiducial);
}

.specimen__caption {
  max-width: var(--measure-cap);
  padding-left: var(--sp-2);
  border-left: 1px solid var(--hairline);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 400;
  line-height: 1.9;
  letter-spacing: var(--track-micro);
  text-transform: uppercase;
  color: var(--ink-faint);
}

/* -------------------------------------------------------------------------
   08 — CARDS (the specimen's own content — stays default)
   ------------------------------------------------------------------------- */
.card {
  position: relative;
  z-index: 1;
  padding: var(--sp-6) var(--sp-4);
  border-radius: 6px;
  background-color: var(--canvas);
  color: var(--ink);
  font-family: var(--font-specimen);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  box-shadow: var(--elev-2);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translate3d(0, 10px, 0);
  clip-path: inset(0 0 100% 0);
  transition:
    opacity var(--dur) var(--ease-out),
    transform var(--dur-slow) var(--ease-out),
    clip-path var(--dur-slow) var(--ease-out),
    box-shadow var(--dur) var(--ease-out),
    visibility 0s linear var(--dur-slow);
}

.card.is-active {
  z-index: 4;
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: none;
  clip-path: inset(-32px);
  transition:
    opacity var(--dur) var(--ease-out),
    transform var(--dur-slow) var(--ease-out),
    clip-path var(--dur-slow) var(--ease-out),
    box-shadow var(--dur) var(--ease-out),
    visibility 0s linear 0s;
}

/* Safety net: if no card is marked active, the first one shows. */
.specimen__stage:not(:has(.card.is-active)) > .card:first-of-type {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: none;
  clip-path: inset(-32px);
}

.card__title {
  margin: 0 0 var(--sp-2);
  font-family: var(--font-specimen);
  font-size: 2rem;
  font-weight: 600;
  line-height: var(--lh-snug);
  letter-spacing: -0.01em;
  color: var(--ink);
  text-wrap: balance;
}

.card__title--small {
  font-size: var(--fs-lead);
  font-weight: 600;
  letter-spacing: -0.005em;
}

.card__body {
  margin: 0 0 var(--sp-2);
  max-width: 52ch;
  font-family: var(--font-specimen);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  color: var(--ink);
}

.card__body:last-child { margin-bottom: 0; }

.card__link {
  position: relative;
  display: inline-block;
  color: var(--link);
  text-decoration: none;
  background-image: linear-gradient(currentColor, currentColor);
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0% 1px;
  transition: background-size var(--dur) var(--ease-out),
              color var(--dur-fast) var(--ease-out);
}

.card__link:hover,
.card__link:focus-visible {
  color: var(--link);
  background-size: 100% 1px;
}

/* --- Chapter 01: the base page ---------------------------------------------- */
.card--base {
  padding-block: var(--sp-8);
}

/* --- Chapter 02: the boundary ------------------------------------------------ */
.card--boundary {
  background-color: var(--canvas);
}

.card--boundary::before {
  content: "";
  position: absolute;
  inset: var(--sp-2);
  border: 1px dashed rgba(17, 17, 17, 0.32);
  border-radius: 3px;
  pointer-events: none;
}

.card__stamp {
  position: absolute;
  right: var(--sp-3);
  bottom: var(--sp-2);
  padding: 4px 8px;
  border: 1px solid var(--fiducial);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 500;
  letter-spacing: var(--track-micro);
  text-transform: uppercase;
  color: var(--fiducial);
  transform: rotate(-6deg);
  mix-blend-mode: multiply;
}

/* --- Chapter 03: ubiquity ----------------------------------------------------- */
.card--ubiquitous {
  background-color: var(--canvas);
}

/* scanline scrim + bottom gradient scrim */
.card--ubiquitous::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(
      180deg,
      rgba(17, 17, 17, 0.055) 0 1px,
      rgba(17, 17, 17, 0) 1px 4px
    ),
    linear-gradient(
      180deg,
      rgba(17, 17, 17, 0) 55%,
      rgba(17, 17, 17, 0.07) 100%
    );
  mix-blend-mode: multiply;
}

/* --- Chapter 04: the spec sheet ------------------------------------------------ */
.card--specsheet {
  padding: var(--sp-5) var(--sp-4) var(--sp-4);
}

.specsheet {
  display: grid;
  gap: 0;
  margin: var(--sp-2) 0 0;
  contain: layout;
}

.specsheet__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: var(--sp-2);
  align-items: baseline;
  padding: var(--sp-2) 0;
  border-bottom: 1px solid rgba(17, 17, 17, 0.12);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  line-height: 1.4;
  letter-spacing: 0.04em;
  color: var(--ink);
  transition: background-color var(--dur-fast) var(--ease-out);
}

.specsheet__row > :last-child {
  color: var(--muted-ink);
  text-align: right;
  white-space: nowrap;
}

.specsheet__row:hover {
  background-color: rgba(51, 68, 136, 0.05);
}

.specsheet__row--last {
  border-bottom: 0;
  padding-bottom: 0;
}

/* --- Chapter 05: the proof ----------------------------------------------------- */
.card--proof {
  background-color: var(--canvas);
  box-shadow: var(--elev-3);
}

.card--proof.is-active {
  clip-path: inset(-48px);
}

.fiducial {
  position: absolute;
  width: 18px;
  height: 18px;
  color: var(--fiducial);
  pointer-events: none;
  opacity: 0;
}

.fiducial::before,
.fiducial::after {
  content: "";
  position: absolute;
  background-color: currentColor;
}

.fiducial::before {
  top: 50%;
  left: 0;
  width: 100%;
  height: 1px;
  transform: translateY(-50%);
}

.fiducial::after {
  left: 50%;
  top: 0;
  width: 1px;
  height: 100%;
  transform: translateX(-50%);
}

.fiducial--tl { top: 0;    left: 0;    transform: translate(-50%, -50%); }
.fiducial--tr { top: 0;    right: 0;   transform: translate(50%, -50%); }
.fiducial--bl { bottom: 0; left: 0;    transform: translate(-50%, 50%); }
.fiducial--br { bottom: 0; right: 0;   transform: translate(50%, 50%); }

.card--proof.is-active .fiducial {
  animation: fiducial-snap 0.34s var(--ease-out) forwards;
}

.card--proof.is-active .fiducial--tl { animation-delay: 0.05s; }
.card--proof.is-active .fiducial--tr { animation-delay: 0.12s; }
.card--proof.is-active .fiducial--bl { animation-delay: 0.19s; }
.card--proof.is-active .fiducial--br { animation-delay: 0.26s; }

@keyframes fiducial-snap {
  from { opacity: 0; scale: 1.6; }
  to   { opacity: 1; scale: 1; }
}

.card__proofmark {
  position: absolute;
  right: var(--sp-3);
  bottom: var(--sp-3);
  padding: 4px 10px;
  border: 1px solid rgba(17, 17, 17, 0.28);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 500;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: rgba(17, 17, 17, 0.5);
  mix-blend-mode: multiply;
  pointer-events: none;
}

/* --- Chapter 06: the handoff ---------------------------------------------------- */
.card--handoff {
  background-color: var(--canvas);
}

.card__body--empty {
  min-height: calc(var(--fs-body) * var(--lh-body) * 3);
  margin-bottom: 0;
}

/* Words that delete themselves. Index via --i, set by script or defaulted. */
.dw {
  display: inline-block;
  opacity: 1;
  transform: none;
  transition: opacity var(--dur) var(--ease-out),
              transform var(--dur) var(--ease-out);
}

@keyframes dw-erase {
  to {
    opacity: 0;
    transform: translate3d(0, -0.28em, 0);
  }
}

.card--handoff.is-active .dw {
  animation: dw-erase 0.42s var(--ease-out) forwards;
  animation-delay: calc(var(--i, 0) * 70ms);
}

.caret {
  display: inline-block;
  width: 0.58em;
  height: 1.02em;
  margin-left: 3px;
  vertical-align: -0.16em;
  background-color: var(--fiducial);
  animation: caret-blink 1.05s steps(1, end) infinite;
}

@keyframes caret-blink {
  0%, 49%   { opacity: 1; }
  50%, 100% { opacity: 0; }
}

/* -------------------------------------------------------------------------
   09 — CHAPTERS (annotation layer)
   ------------------------------------------------------------------------- */
.chapter {
  position: relative;
  display: grid;
  gap: var(--sp-2);
  align-content: start;
  padding-block: var(--sp-8) var(--sp-10);
  border-top: 1px solid var(--hairline);
  scroll-margin-top: var(--sp-8);
}

.chapter:first-child {
  padding-top: var(--sp-4);
  border-top-color: transparent;
}

.chapter__eyebrow {
  display: flex;
  align-items: baseline;
  gap: var(--sp-1);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: var(--track-micro);
  text-transform: uppercase;
  color: var(--ink-faint);
}

.chapter__rule {
  position: relative;
  width: min(180px, 42%);
  height: 1px;
  margin-block: var(--sp-1) var(--sp-2);
  transform-origin: left center;
  background-image: linear-gradient(
    90deg,
    rgba(51, 68, 136, 1) 0%,
    rgba(51, 68, 136, 0.12) 100%
  );
}

.chapter__kicker {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-h4);
  font-weight: 500;
  line-height: var(--lh-snug);
  letter-spacing: -0.01em;
  color: var(--canvas);
}

.chapter__title {
  margin: 0;
  font-family: var(--font-sans);
  font-size: clamp(2.125rem, 8vw, var(--fs-display));
  font-weight: 600;
  line-height: var(--lh-tight);
  letter-spacing: var(--track-display);
  color: var(--canvas);
  text-wrap: balance;
}

.chapter__body {
  max-width: var(--measure);
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-lead);
  font-weight: 400;
  line-height: var(--lh-prose);
  color: var(--ink-soft);
  text-wrap: pretty;
}

.chapter.is-active .chapter__eyebrow { color: var(--canvas); }

/* --- Spec rows ------------------------------------------------------------------ */
.specs {
  display: grid;
  gap: 0;
  margin-top: var(--sp-2);
  border-top: 1px solid var(--hairline);
}

.specs__row {
  display: grid;
  grid-template-columns: minmax(0, 12ch) minmax(0, 1fr);
  gap: var(--sp-2);
  align-items: baseline;
  padding: var(--sp-2) 0;
  border-bottom: 1px solid var(--hairline);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  font-weight: 400;
  letter-spacing: 0.06em;
  line-height: 1.5;
  color: var(--ink-soft);
  transition: color var(--dur-fast) var(--ease-out),
              padding-left var(--dur-fast) var(--ease-out);
}

.specs__row > :first-child {
  text-transform: uppercase;
  color: var(--ink-faint);
}

.specs__row:hover {
  color: var(--canvas);
  padding-left: var(--sp-1);
}

/* --- Margin notes --------------------------------------------------------------- */
.note {
  display: grid;
  gap: var(--sp-1);
  margin-top: var(--sp-2);
  padding-left: var(--sp-2);
  border-left: 2px solid var(--link);
  transition: border-color var(--dur) var(--ease-out);
}

.note:hover { border-left-color: var(--fiducial); }

.note__label {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 500;
  letter-spacing: var(--track-micro);
  text-transform: uppercase;
  color: var(--ink-faint);
}

.note__text {
  max-width: 52ch;
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: var(--lh-prose);
  color: var(--ink-soft);
}

/* -------------------------------------------------------------------------
   10 — COLOPHON
   ------------------------------------------------------------------------- */
.colophon {
  position: relative;
  z-index: 2;
  padding: var(--sp-8) var(--sp-3) var(--sp-12);
  border-top: 1px solid var(--hairline);
  background-image: linear-gradient(
    180deg,
    rgba(16, 20, 24, 1) 0%,
    rgba(16, 20, 24, 0.9) 100%
  );
}

.colophon__grid {
  display: grid;
  gap: var(--sp-4);
  max-width: 1240px;
  margin-inline: auto;
}

.colophon__brand {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-family: var(--font-mono);
  font-size: var(--fs-small);
  font-weight: 500;
  letter-spacing: var(--track-micro);
  text-transform: uppercase;
  color: var(--ink-faint);
}

.colophon__mark {
  position: relative;
  flex: 0 0 auto;
  width: 22px;
  height: 22px;
  border: 1px solid var(--ink-ghost);
}

.colophon__mark::after {
  content: "";
  position: absolute;
  top: 3px;
  left: 3px;
  width: 4px;
  height: 4px;
  background-color: var(--fiducial);
}

.colophon__statement {
  max-width: var(--measure);
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--fs-lead);
  line-height: var(--lh-prose);
  color: var(--ink-soft);
}

/* -------------------------------------------------------------------------
   11 — SCROLL-DRIVEN REVEAL (progressive enhancement)
   ------------------------------------------------------------------------- */
@keyframes reveal-rise {
  from { opacity: 0; transform: translate3d(0, 20px, 0); }
  to   { opacity: 1; transform: none; }
}

@keyframes reveal-rule {
  from { opacity: 0.15; transform: scaleX(0); }
  to   { opacity: 1;    transform: scaleX(1); }
}

@keyframes ghost-drift {
  from { translate: 0 0; }
  to   { translate: 0 -14px; }
}

@supports (animation-timeline: view()) {
  @media (prefers-reduced-motion: no-preference) {
    .chapter__eyebrow,
    .chapter__kicker,
    .chapter__title,
    .chapter__body,
    .specs,
    .note,
    .specimen__caption {
      animation: reveal-rise linear both;
      animation-timeline: view();
      animation-range: entry 4% cover 26%;
    }

    .chapter__rule {
      animation: reveal-rule linear both;
      animation-timeline: view();
      animation-range: entry 4% cover 30%;
    }
  }
}

/* Ghost drift — independent of transform (rotation stays intact) */
@media (prefers-reduced-motion: no-preference) {
  .ghost--1 { animation: ghost-drift 22s ease-in-out infinite alternate; }
  .ghost--2 { animation: ghost-drift 28s ease-in-out infinite alternate; animation-delay: -6s; }
  .ghost--3 { animation: ghost-drift 26s ease-in-out infinite alternate; animation-delay: -12s; }
  .ghost--4 { animation: ghost-drift 31s ease-in-out infinite alternate; animation-delay: -3s; }
  .ghost--5 { animation: ghost-drift 24s ease-in-out infinite alternate; animation-delay: -9s; }
  .ghost--chrome { animation: ghost-drift 34s ease-in-out infinite alternate; animation-delay: -15s; }
}

/* -------------------------------------------------------------------------
   12 — REDUCED MOTION
   ------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  .card {
    transform: none;
    clip-path: none;
  }

  .card.is-active {
    clip-path: none;
  }

  .fiducial { opacity: 1; }

  .caret { animation: none; opacity: 1; }
}

/* -------------------------------------------------------------------------
   13 — BREAKPOINT: 768px
   ------------------------------------------------------------------------- */
@media (min-width: 768px) {
  .masthead {
    padding: var(--sp-10) var(--sp-5) var(--sp-8);
  }

  .narrative {
    padding: var(--sp-10) var(--sp-5) var(--sp-16);
    gap: var(--sp-12);
  }

  .card {
    padding: var(--sp-8) var(--sp-6);
  }

  .card--specsheet {
    padding: var(--sp-6) var(--sp-6) var(--sp-5);
  }

  .card--base {
    padding-block: var(--sp-10);
  }

  .specimen__ticks {
    display: block;
  }

  .chapter {
    padding-block: var(--sp-10) var(--sp-12);
  }

  .colophon {
    padding: var(--sp-10) var(--sp-5) var(--sp-16);
  }

  .colophon__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr);
    align-items: start;
    gap: var(--sp-8);
  }

  .colophon__statement {
    grid-column: 2;
  }
}

/* -------------------------------------------------------------------------
   14 — BREAKPOINT: 1024px — specimen pins, chapters scroll beside it
   ------------------------------------------------------------------------- */
@media (min-width: 1024px) {
  .narrative {
    grid-template-columns: minmax(0, 640px) minmax(0, 1fr);
    grid-template-rows: auto;
    align-items: start;
    gap: var(--sp-12) var(--sp-16);
    max-width: 1240px;
    margin-inline: auto;
    padding: var(--sp-12) var(--sp-5) var(--sp-24);
  }

  .narrative__specimen {
    grid-column: 1;
    grid-row: 1;
    position: sticky;
    top: var(--sp-6);
    align-self: start;
  }

  .narrative__chapters {
    grid-column: 2;
    grid-row: 1;
    gap: var(--sp-16);
  }

  .specimen__ghosts {
    inset: -16% -18%;
  }

  .chapter__title {
    font-size: clamp(2.6rem, 4.6vw, var(--fs-display));
  }

  .chapter__kicker {
    font-size: var(--fs-h3);
    font-weight: 500;
  }
}

/* -------------------------------------------------------------------------
   15 — BREAKPOINT: 1280px
   ------------------------------------------------------------------------- */
@media (min-width: 1280px) {
  .narrative {
    grid-template-columns: minmax(0, 680px) minmax(0, 1fr);
    gap: var(--sp-12) var(--sp-24);
  }

  .masthead__inner {
    gap: var(--sp-3);
  }

  .specimen__ghosts {
    inset: -18% -22%;
  }
}

/* -------------------------------------------------------------------------
   16 — HOVER-CAPABLE POINTERS
   ------------------------------------------------------------------------- */
@media (hover: hover) and (pointer: fine) {
  .card--boundary.is-active:hover .card__stamp {
    transform: rotate(-6deg) scale(1.04);
    transition: transform var(--dur) var(--ease-out);
  }

  .ghost {
    transition: opacity var(--dur) var(--ease-out), color var(--dur) var(--ease-out);
  }

  .specimen:hover .ghost {
    opacity: 0.85;
    color: rgba(238, 238, 238, 0.26);
  }

  .colophon__mark {
    transition: border-color var(--dur) var(--ease-out);
  }

  .colophon:hover .colophon__mark {
    border-color: var(--ink-faint);
  }
}