/* ==========================================================================
   PsychoPilot — "Perception Press" (visual prototype)
   Main style: mid-century modern book design (Pelican/Penguin, Lustig, Rand):
     cut-paper colour blocks, asymmetric compositions, a book-series rhythm.
   Fused: Albers colour relativity · riso two-ink print · generative art (Molnár)
     · per-volume accents (Cajal, Op Art, Rothko, Isotype, Agnes Martin, Seurat).
   Rule: every image is a real psychological phenomenon. Two inks + paper only.
   ========================================================================== */

:root {
  --paper: #f2ece1;
  --paper-2: #e8dfcf;
  --blue: #22305a;      /* ink 1 */
  --red: #e2533a;       /* ink 2 */
  --text: #1d2440;
  --text-2: #4c516a;
  --text-3: #8a8a94;
  --rule: rgba(34, 48, 90, .16);
  --on-blue: #f2ece1;
  --mid: #8b7f8f;       /* the Albers grey: two inks overprinted, thinned */

  --head: "Jost", "Futura", "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --body: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei UI", "Microsoft YaHei", system-ui, sans-serif;
  --mono: "IBM Plex Mono", "Cascadia Mono", Consolas, ui-monospace, monospace;

  --gutter: clamp(18px, 4.5vw, 72px);
  --maxw: 1360px;
  --ease: cubic-bezier(.22, 1, .36, 1);
  color-scheme: light;  /* the site is light only, by design */
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0; background: var(--paper); color: var(--text);
  font: 16px/1.75 var(--body); -webkit-font-smoothing: antialiased; overflow-x: clip;
}
/* riso grain over everything */
body::after {
  content: ""; position: fixed; inset: 0; pointer-events: none; z-index: 50; opacity: .09; mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='1.1' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 0.13 0 0 0 0 0.16 0 0 0 0 0.3 0 0 0 1.2 -0.25'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
a { color: inherit; text-decoration: none; }
h1, h2, h3, p { margin: 0; }
button { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--red); outline-offset: 3px; }
.wrap { max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gutter); }
.lab { font: 500 11.5px/1.4 var(--mono); letter-spacing: .12em; text-transform: uppercase; color: var(--text-3); }
.num { display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; background: var(--red); color: var(--paper); font: 600 13px/1 var(--head); }

/* ---------- Masthead (scrolls away) ---------- */
.mast { display: flex; justify-content: space-between; align-items: center; gap: 16px; padding-block: clamp(18px, 2.6vw, 30px); }
.logo { display: inline-flex; align-items: center; gap: 12px; font: 700 20px/1 var(--head); letter-spacing: -.01em; }
.logo i { position: relative; width: 26px; height: 26px; }
.logo i::before, .logo i::after { content: ""; position: absolute; width: 18px; height: 18px; border-radius: 50%; mix-blend-mode: multiply; }
.logo i::before { left: 0; top: 4px; background: var(--blue); }
.logo i::after { right: 0; top: 4px; background: var(--red); }
.mast nav { display: flex; gap: 26px; font-size: 14.5px; color: var(--text-2); }
.mast nav a:hover { color: var(--red); }

/* ---------- Hero ---------- */
.hero {
  display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); gap: clamp(28px, 5vw, 80px);
  align-items: center; padding-block: clamp(16px, 3vw, 40px) clamp(56px, 7vw, 96px);
}
.hero h1 { font: 800 clamp(2.6rem, 5.4vw, 5.1rem)/1.08 var(--head); letter-spacing: -.02em; margin-top: 20px; }
.hero h1 .r { color: var(--red); }
.hero .lede { margin-top: 26px; max-width: 27em; color: var(--text-2); font-size: 1.05rem; }

.search { position: relative; margin-top: 36px; max-width: 470px; }
.field { display: flex; align-items: center; gap: 12px; border: 2px solid var(--text); border-radius: 999px; padding: 4px 6px 4px 18px; background: var(--paper); transition: box-shadow .3s; }
.field:focus-within { box-shadow: 5px 5px 0 var(--red); }
.field svg { flex: none; }
.field input { flex: 1; min-width: 0; border: 0; background: none; color: inherit; font: 16px/1.4 var(--body); padding: 11px 0; outline: none; }
.field input::placeholder { color: var(--text-3); }
.field input::-webkit-search-cancel-button { display: none; }
.field kbd { font: 11px var(--mono); color: var(--text-3); border: 1px solid var(--rule); border-radius: 6px; padding: 2px 8px; margin-right: 8px; }
.results {
  position: absolute; z-index: 20; left: 0; right: 0; top: calc(100% + 10px); margin: 0; padding: 6px; list-style: none;
  max-height: 380px; overflow: auto; background: var(--paper); border: 2px solid var(--text); border-radius: 18px; box-shadow: 6px 6px 0 var(--blue);
}
.results[hidden] { display: none; }
.results a { display: grid; grid-template-columns: 52px minmax(0, 1fr); gap: 0 8px; padding: 9px 12px; border-radius: 12px; }
.results a[aria-selected="true"], .results a:hover { background: var(--paper-2); }
.results .rid { grid-row: span 2; font: 12px var(--mono); color: var(--text-3); padding-top: 4px; }
.results .rt { font-weight: 600; }
.results .rs { font-size: 13px; color: var(--text-3); }
.results mark { background: none; color: var(--red); }
.results .empty { padding: 12px; font-size: 14px; color: var(--text-3); }

.continue { display: inline-flex; align-items: center; gap: 12px; margin-top: 22px; }
.continue .k { display: block; font: 12px var(--mono); color: var(--text-3); letter-spacing: .06em; }
.continue .t { font-weight: 600; border-bottom: 2px solid var(--red); }
.continue:hover .t { color: var(--red); }

/* the Gestalt plate: a cut-paper block of blue ink */
.plate { position: relative; }
.plate-art { position: relative; aspect-ratio: 5 / 4; background: var(--blue); border-radius: 4px 4px 140px 4px; overflow: hidden; }
.plate-art canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.plate-dot { position: absolute; width: 22%; aspect-ratio: 1; border-radius: 50%; background: var(--red); right: -5%; top: -7%; mix-blend-mode: multiply; z-index: 2; pointer-events: none; }
.plate-cap { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 4px 16px; margin-top: 18px; align-items: start; }
.plate-k { display: block; margin-bottom: 2px; line-height: 28px; }
.plate-cap h2 { font: 700 1.25rem/1.35 var(--head); }
.plate-cap h2 small { font: 500 12px var(--mono); letter-spacing: .1em; color: var(--text-3); margin-left: 8px; text-transform: uppercase; }
.plate-cap p { grid-column: 2; color: var(--text-2); font-size: 15px; max-width: 34em; }
.laws { display: flex; gap: 6px; margin-top: 14px; grid-column: 2; }
.laws button { width: 30px; height: 6px; border: 0; border-radius: 3px; background: var(--rule); cursor: pointer; padding: 0; transition: background .3s, width .4s var(--ease); }
.laws button[aria-pressed="true"] { background: var(--red); width: 46px; }

/* ---------- Section heads ---------- */
.section { padding-block: clamp(56px, 8vw, 112px); border-top: 2px solid var(--text); }
.sh { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: end; gap: 12px 24px; margin-bottom: clamp(28px, 4vw, 48px); }
.sh h2 { font: 800 clamp(1.9rem, 3.6vw, 3rem)/1.1 var(--head); letter-spacing: -.015em; margin-top: 10px; }
.sh p { color: var(--text-2); max-width: 30em; }

/* ---------- The six volumes ---------- */
.shelf { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: clamp(12px, 1.6vw, 22px); list-style: none; margin: 0; padding: 0; }
.cover {
  --bg: var(--paper-2); --fg: var(--text); --fg-2: var(--text-2);
  position: relative; display: flex; flex-direction: column; aspect-ratio: 5 / 7.4; padding: 14px 14px 12px;
  background: var(--bg); color: var(--fg); border-radius: 3px;
  box-shadow: 0 1px 0 rgba(0, 0, 0, .06), 0 18px 30px -22px rgba(20, 24, 50, .55);
  transition: transform .6s var(--ease), box-shadow .6s var(--ease);
}
.cover:hover, .cover:focus-visible { transform: translateY(-8px) rotate(-.6deg); box-shadow: 0 1px 0 rgba(0, 0, 0, .06), 0 30px 40px -24px rgba(20, 24, 50, .6); }
.cover.on-blue { --bg: var(--blue); --fg: var(--on-blue); --fg-2: rgba(242, 236, 225, .7); }
.cover.on-red { --bg: var(--red); --fg: #fff8ee; --fg-2: rgba(255, 248, 238, .78); }
.cover .top { display: flex; justify-content: space-between; font: 500 10.5px/1 var(--mono); letter-spacing: .12em; text-transform: uppercase; color: var(--fg-2); }
.cover .vol { font: 300 clamp(1.6rem, 2.6vw, 2.4rem)/1 var(--head); margin-top: 10px; }
.cover canvas { flex: 1; width: 100%; min-height: 0; display: block; margin-block: 8px; }
.cover h3 { font: 700 clamp(.98rem, 1.15vw, 1.12rem)/1.35 var(--head); }
.cover .fig { margin-top: 6px; font: 500 10px/1.3 var(--mono); letter-spacing: .08em; color: var(--fg-2); text-transform: uppercase; }
.shelf .meta { margin-top: 12px; font-size: 13.5px; color: var(--text-2); line-height: 1.55; }
.shelf .meta b { font: 600 12px var(--mono); color: var(--text-3); margin-right: 6px; }

/* ---------- Albers experiment ---------- */
.exp { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: clamp(28px, 5vw, 80px); align-items: center; }
.exp h2 { font: 800 clamp(1.9rem, 3.6vw, 3rem)/1.12 var(--head); margin-top: 12px; }
.exp p { margin-top: 18px; color: var(--text-2); max-width: 28em; }
.choices { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.choice { border: 2px solid var(--text); background: var(--paper); border-radius: 999px; padding: 9px 20px; font-weight: 600; cursor: pointer; transition: transform .3s var(--ease), box-shadow .3s; }
.choice:hover { transform: translate(-2px, -2px); box-shadow: 3px 3px 0 var(--text); }
.choice[aria-pressed="true"] { background: var(--text); color: var(--paper); }
.answer { margin-top: 20px; min-height: 3.5em; font-size: 15px; }
.answer a { border-bottom: 2px solid var(--red); font-weight: 600; }
.albers svg { width: 100%; height: auto; display: block; }
.albers .bridge { transform-origin: 50% 50%; transform: scaleX(0); transition: transform 1.1s var(--ease); transform-box: fill-box; }
.albers.is-revealed .bridge { transform: scaleX(1); }

/* ---------- Interests + footer ---------- */
.links { font: 700 clamp(1.3rem, 2.4vw, 2rem)/1.7 var(--head); }
.links a { background: linear-gradient(var(--red), var(--red)) 0 92% / 0 .14em no-repeat; transition: background-size .45s var(--ease); }
.links a:hover { background-size: 100% .14em; }
.links .sep { color: var(--text-3); font-weight: 300; margin-inline: .3em; }
.foot { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 20px; padding-block: 36px 52px; border-top: 2px solid var(--text); font-size: 13.5px; color: var(--text-3); }

/* ==========================================================================
   VOLUME (Part) PAGE — the book on the table, then its table of contents
   ========================================================================== */
.back { display: inline-flex; align-items: center; gap: 10px; font-weight: 600; }
.back .num { transition: transform .5s var(--ease); }
.back:hover .num { transform: translateX(-4px); }
.v-hero { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 6fr); gap: clamp(32px, 6vw, 96px); align-items: center; padding-block: clamp(16px, 3vw, 40px) clamp(56px, 7vw, 96px); }
.v-hero .cover { max-width: 400px; width: 100%; justify-self: center; transform: rotate(-2deg); }
.v-hero .cover:hover { transform: rotate(-1deg) translateY(-6px); }
.v-hero .cover .vol { font-size: clamp(2.4rem, 4vw, 3.6rem); }
.v-hero .cover h3 { font-size: clamp(1.2rem, 1.8vw, 1.5rem); }
.v-hero .cover .fig { font-size: 11px; }
.stack { position: relative; height: clamp(320px, 34vw, 460px); max-width: 420px; width: 100%; justify-self: center; }
.stack .cover { position: absolute; width: 58%; top: 0; }
.v-hero h1 { font: 800 clamp(2.3rem, 4.6vw, 4.2rem)/1.1 var(--head); letter-spacing: -.02em; margin-top: 16px; }
.v-hero .lede { margin-top: 22px; max-width: 30em; color: var(--text-2); font-size: 1.06rem; }
.v-hero .facts { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.v-hero .facts span { border: 2px solid var(--text); border-radius: 999px; padding: 4px 14px; font: 600 13px/1.4 var(--body); }
.v-hero .facts span.r { background: var(--red); border-color: var(--red); color: #fff8ee; }

.toc { counter-reset: none; }
.chap { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); gap: 16px clamp(24px, 4vw, 64px); padding-block: clamp(36px, 5vw, 56px); border-top: 2px solid var(--text); }
.chap-head .big { display: inline-grid; place-items: center; width: 64px; height: 64px; border-radius: 50%; background: var(--blue); color: var(--on-blue); font: 700 1.35rem/1 var(--head); }
.chap:nth-child(3n+2) .chap-head .big { background: var(--red); color: #fff8ee; }
.chap:nth-child(3n+3) .chap-head .big { background: none; color: var(--text); box-shadow: inset 0 0 0 2px var(--text); }
.chap-head h2 { font: 800 clamp(1.35rem, 2.2vw, 1.75rem)/1.3 var(--head); margin-top: 18px; }
.chap-head .from { display: inline-block; margin-top: 10px; }
.chap-head a.from:hover { color: var(--red); }
.lessons { list-style: none; margin: 0; padding: 0; }
.lessons li + li { border-top: 1px solid var(--rule); }
.lesson { display: grid; grid-template-columns: 64px minmax(0, 1fr) 28px; gap: 12px; align-items: baseline; padding: 16px 0; }
.lesson .lid { font: 500 12.5px var(--mono); color: var(--text-3); }
.lesson .lt { font-weight: 700; font-size: 1.06rem; line-height: 1.5; background: linear-gradient(var(--red), var(--red)) 0 100% / 0 2px no-repeat; transition: background-size .45s var(--ease); }
.lesson .ls { display: block; font-size: 14px; color: var(--text-2); margin-top: 2px; }
.lesson .go { font-weight: 700; color: var(--red); opacity: 0; transform: translateX(-8px); transition: opacity .3s, transform .45s var(--ease); }
.lesson:hover .lt, .lesson:focus-visible .lt { background-size: 100% 2px; }
.lesson:hover .go, .lesson:focus-visible .go { opacity: 1; transform: none; }

.v-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; padding-block: clamp(40px, 5vw, 64px); border-top: 2px solid var(--text); }
.v-nav a { display: flex; align-items: center; gap: 18px; }
.v-nav a.next { flex-direction: row-reverse; text-align: right; }
.v-nav .cover { width: 92px; flex: none; padding: 8px; }
.v-nav .cover .top, .v-nav .cover h3, .v-nav .cover .fig { display: none; }
.v-nav .cover .vol { font-size: 1.1rem; margin: 0; }
.v-nav .t { display: block; margin-top: 4px; font: 800 clamp(1.1rem, 1.8vw, 1.45rem)/1.3 var(--head); }
.v-nav a:hover .t { color: var(--red); }
.v-nav .links { grid-column: 1 / -1; }

/* ==========================================================================
   LESSON (course) PAGE — placeholder
   ========================================================================== */
.l-hero { display: grid; grid-template-columns: minmax(0, 8fr) minmax(0, 3fr); gap: clamp(24px, 5vw, 72px); align-items: start; padding-block: clamp(40px, 7vw, 96px) clamp(40px, 5vw, 64px); }
.l-hero .crumb { display: flex; flex-wrap: wrap; gap: 4px 18px; }
.l-hero .crumb a:hover { color: var(--red); }
.l-hero h1 { font: 800 clamp(2rem, 4.4vw, 3.8rem)/1.18 var(--head); letter-spacing: -.015em; margin-top: 22px; }
.l-hero .lede { margin-top: 18px; font-size: 1.2rem; color: var(--text-2); }
.stamp {
  justify-self: end; display: grid; place-items: center; text-align: center; width: 150px; aspect-ratio: 1; border-radius: 50%;
  border: 3px solid var(--red); color: var(--red); transform: rotate(-12deg); padding: 18px; margin-top: 12px;
  font: 800 1.15rem/1.25 var(--head); mix-blend-mode: multiply; opacity: .9;
}
.stamp small { display: block; font: 500 10px/1.3 var(--mono); letter-spacing: .12em; margin-top: 6px; }
.l-note { max-width: 40em; padding-block: 24px 48px; color: var(--text-2); }
.l-note p + p { margin-top: 12px; }
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; padding-block: 40px; border-top: 2px solid var(--text); }
.pager a.next { text-align: right; }
.pager .t { display: block; margin-top: 6px; font: 700 1.1rem/1.5 var(--head); }
.pager a:hover .t { color: var(--red); }

@media (max-width: 900px) {
  .v-hero, .chap, .l-hero { grid-template-columns: 1fr; }
  .v-hero .cover { max-width: 300px; }
  .stack { height: 340px; }
  .stamp { justify-self: start; width: 120px; font-size: 1rem; }
}
@media (max-width: 600px) {
  .v-nav, .pager { grid-template-columns: 1fr; }
  .v-nav a.next { flex-direction: row; text-align: left; }
  .pager a.next { text-align: left; }
  .lesson { grid-template-columns: 52px minmax(0, 1fr); }
  .lesson .go { display: none; }
}

/* ---------- Responsive ---------- */
@media (max-width: 1080px) {
  .shelf { grid-template-columns: repeat(3, minmax(0, 1fr)); row-gap: 32px; }
}
@media (max-width: 900px) {
  .hero, .exp, .foot { grid-template-columns: 1fr; }
  .plate { margin-top: 8px !important; }
}
@media (max-width: 600px) {
  .mast nav { display: none; }
  .field kbd { display: none; }
  .shelf { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .plate-art { border-radius: 4px 4px 80px 4px; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { transition-duration: .01ms !important; } }