/* The book that opens on scroll: a made-up publisher, Bramble Press. The stage sticks while you scroll; the book, its
   pages, the shadows and the light are placed by the script, which also reads the colours below. */
:root {
  --tavolo: #f2eee6;         /* the table, the page around the book */
  --inchiostro: #191714;     /* the text */
  --tenue: #8d877c;          /* the small text */
  --tela: #cfc6b4;           /* the cloth of the cover */
  --tela-scura: #b9af9b;     /* the cloth of the back cover and the spine */
  --risguardo: #e6dfd0;      /* the endpaper inside the cover */
  --carta: #fbf8f1;          /* the pages */
  --taglio: #ece5d6;         /* the edge of the stacked pages */
  --accento: #d9482b;        /* the ribbon bookmark, the only colour */
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
}

body {
  background: var(--tavolo);
  color: var(--inchiostro);
  font-family: 'Instrument Sans Variable', 'Instrument Sans', system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

html.lenis,
html.lenis body {
  height: auto;
}

.lenis.lenis-smooth {
  scroll-behavior: auto !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* ---------------------------------------------------------------- the stage */
.corsa {
  position: relative;
  height: 420lvh; /* the script sets the real height from RIDE */
}

.palco {
  position: sticky;
  top: 0;
  height: 100lvh;
  overflow: hidden;
  background: var(--tavolo);
}

.testa {
  position: absolute;
  inset: 0 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: clamp(14px, 3.2vh, 30px) clamp(16px, 4vw, 44px);
  z-index: 2;
}

.marchio {
  color: var(--inchiostro);
  text-decoration: none;
  font-family: 'Newsreader Variable', 'Newsreader', Georgia, serif;
  font-size: clamp(14px, 1.4vw, 17px);
  font-weight: 560;
  letter-spacing: 0.01em;
}

.testa__nota,
.cenno {
  margin: 0;
  font-size: clamp(11px, 1vw, 13px);
  color: var(--tenue);
  letter-spacing: 0.02em;
}

.cenno {
  position: absolute;
  left: 0;
  right: 0;
  bottom: clamp(14px, 4vh, 34px);
  text-align: center;
  z-index: 2;
}

/* ---------------------------------------------------------------- the book */
.scena {
  position: absolute;
  inset: 0;
  perspective: 1700px;
  perspective-origin: 50% 30%;
}

.libro,
.libro * {
  transform-style: preserve-3d;
}

.libro {
  position: absolute;
  left: 50%;
  top: 50%;
  transform-origin: 0 50%;
}

.faccia,
.libro .foglio,
.libro .segmento {
  position: absolute;
  left: 0;
  top: 0;
}

.dorso-retro {
  background: var(--tela-scura);
  border-radius: 1px 3px 3px 1px;
}

.blocco {
  background: var(--carta);
}

.pagina-base {
  position: absolute;
  inset: 0;
  overflow: hidden;
  background: linear-gradient(90deg, rgba(60, 45, 25, 0.10), rgba(60, 45, 25, 0) 9%), var(--carta);
  font-family: 'Newsreader Variable', 'Newsreader', Georgia, serif;
}

.pagina-base__capitolo {
  position: absolute;
  left: 15%;
  right: 12%;
  top: 22%;
  margin: 0;
  font-style: italic;
  font-size: var(--testo-piccolo, 11px);
  color: var(--tenue);
  letter-spacing: 0.02em;
}

.pagina-base__frase {
  position: absolute;
  left: 15%;
  right: 12%;
  top: 30%;
  margin: 0;
  font-size: var(--testo, 20px);
  line-height: 1.16;
  font-variation-settings: 'opsz' 36;
  color: var(--inchiostro);
  text-wrap: balance;
}

.pagina-base__ombra {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(40, 30, 15, 0.55), rgba(40, 30, 15, 0) 70%);
  opacity: 0;
  pointer-events: none;
}

.nastro {
  position: absolute;
  background: linear-gradient(90deg, rgba(0, 0, 0, 0.08), rgba(255, 255, 255, 0.12) 45%, rgba(0, 0, 0, 0.1)), var(--accento);
  transform-origin: 50% 0;
  border-radius: 0 0 1px 1px;
}

/* the tail of the ribbon is cut in a little V */
.nastro::after {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 7px;
  background: linear-gradient(to bottom right, transparent 49%, var(--tavolo) 51%) left / 50% 100% no-repeat,
    linear-gradient(to bottom left, transparent 49%, var(--tavolo) 51%) right / 50% 100% no-repeat;
}

.taglio {
  transform-origin: 0 0;
  background: repeating-linear-gradient(var(--verso, 180deg), var(--taglio) 0 1.2px, #d9d0bd 1.2px 1.6px);
}

.taglio--davanti {
  --verso: 90deg;
}

/* the pages: each one is a few thin strips hinged one on the next, so it can curve while it turns */
.foglio {
  transform-origin: 0 50%;
}

.segmento {
  height: 100%;
  transform-origin: 0 50%;
}

.segmento > .lato {
  position: absolute;
  inset: 0;
  box-shadow: inset 0 0.6px 0 rgba(90, 70, 40, 0.16), inset 0 -0.6px 0 rgba(90, 70, 40, 0.16);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  background: var(--carta);
}

.segmento > .lato--retro {
  transform: rotateY(180deg);
  background: #f8f5ee;
}

.lato::after {
  content: '';
  position: absolute;
  inset: 0;
  background: #2a2216;
  opacity: var(--buio, 0);
}

.copertina {
  transform-origin: 0 50%;
}

.copertina__fuori,
.copertina__dentro {
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: 1px 3px 3px 1px;
  overflow: hidden;
}

.copertina__fuori {
  background:
    repeating-linear-gradient(0deg, rgba(255, 255, 255, 0.07) 0 1px, transparent 1px 3px),
    repeating-linear-gradient(90deg, rgba(0, 0, 0, 0.05) 0 1px, transparent 1px 3px),
    linear-gradient(90deg, rgba(0, 0, 0, 0.16), rgba(0, 0, 0, 0) 7%, rgba(255, 255, 255, 0.08) 8%, rgba(0, 0, 0, 0) 12%),
    var(--tela);
}

.copertina__titolo {
  position: absolute;
  left: 16%;
  right: 10%;
  top: 18%;
  font-family: 'Newsreader Variable', 'Newsreader', Georgia, serif;
  font-size: var(--titolo, 34px);
  font-weight: 520;
  line-height: 0.95;
  letter-spacing: -0.01em;
  color: #b8ae99;
  /* pressed into the cloth: a dark line above each stroke, a light one below */
  text-shadow: 0 -1px 0 rgba(70, 55, 35, 0.45), 0 1px 0 rgba(255, 255, 255, 0.45);
}

.copertina__autore {
  position: absolute;
  left: 16%;
  bottom: 12%;
  font-size: var(--testo-piccolo, 11px);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #aa9f88;
  text-shadow: 0 -1px 0 rgba(70, 55, 35, 0.35), 0 1px 0 rgba(255, 255, 255, 0.4);
}

.copertina__dentro {
  transform: rotateY(180deg);
  background: linear-gradient(270deg, rgba(60, 45, 25, 0.12), rgba(60, 45, 25, 0) 10%), var(--risguardo);
}

.copertina__ex {
  position: absolute;
  left: 0;
  right: 0;
  top: 46%;
  text-align: center;
  font-family: 'Newsreader Variable', 'Newsreader', Georgia, serif;
  font-style: italic;
  font-size: var(--testo-piccolo, 11px);
  color: #a99f8c;
}

.copertina__luce {
  position: absolute;
  inset: 0;
  background: #20190f;
  opacity: 0;
  pointer-events: none;
}

.copertina__spessore {
  background: var(--tela-scura);
  transform-origin: 0 0;
}

.ombra {
  position: absolute;
  left: 50%;
  top: 50%;
  border-radius: 50%;
  background: radial-gradient(closest-side, rgba(60, 45, 25, 0.3), rgba(60, 45, 25, 0.12) 60%, rgba(60, 45, 25, 0));
  filter: blur(14px);
  transform-origin: 0 50%;
}

/* ---------------------------------------------------------------- after the book */
.dopo {
  min-height: 60lvh;
  display: grid;
  place-items: center;
  padding: 40px 20px;
}

.dopo__testo {
  margin: 0;
  max-width: 34ch;
  text-align: center;
  font-family: 'Newsreader Variable', 'Newsreader', Georgia, serif;
  font-size: clamp(16px, 2vw, 22px);
  color: var(--tenue);
}