/* Layout: a research notebook index. Masthead with the five-directions mark and a
   papers-per-day strip, a sticky filter bar, then one reading column of day groups. */
:root {
  --bg: #f3f5f8;
  --paper: #ffffff;
  --ink: #161a23;
  --ink-2: #464e60;
  --ink-3: #737b8d;
  --rule: #dce1e9;
  --theory: #5a3fd0;
  --theory-soft: #ece8fc;
  --recovery: #0d7464;
  --recovery-soft: #dff2ee;
  --broader: #855600;
  --broader-soft: #f5ecd9;
  --accent: #5a3fd0;
  --focus: #5a3fd0;
  --bar: #c3cad6;
  --grid: #e9edf3;
  --rule-strong: #c6cdd9;
  --on-accent: #ffffff;
  --shadow: rgba(22, 26, 40, 0.18);
  --font-display: "Literata", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --font-body: "IBM Plex Sans", "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;
  --step--1: 0.8125rem;
  --step-0: 0.9375rem;
  --step-1: 1.125rem;
  --step-2: 1.5rem;
  --step-3: 2rem;
  --measure: 72ch;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1218; --paper: #161a22; --ink: #e6e9ef; --ink-2: #b2b9c8; --ink-3: #868ea0;
    --rule: #272d39; --theory: #a996ff; --theory-soft: #251e46; --recovery: #4bcdb8;
    --recovery-soft: #0f2f2a; --broader: #e2b65a; --broader-soft: #33280f; --accent: #a996ff;
    --focus: #a996ff; --bar: #3a4252; --grid: #1a1f29; --rule-strong: #353c4b;
    --on-accent: #15112c; --shadow: rgba(0, 0, 0, 0.45); color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0f1218; --paper: #161a22; --ink: #e6e9ef; --ink-2: #b2b9c8; --ink-3: #868ea0;
  --rule: #272d39; --theory: #a996ff; --theory-soft: #251e46; --recovery: #4bcdb8;
  --recovery-soft: #0f2f2a; --broader: #e2b65a; --broader-soft: #33280f; --accent: #a996ff;
  --focus: #a996ff; --bar: #3a4252; --grid: #1a1f29; --rule-strong: #353c4b;
    --on-accent: #15112c; --shadow: rgba(0, 0, 0, 0.45); color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 400 var(--step-0)/1.6 var(--font-body);
}
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; border-radius: 3px; }
code { font-family: var(--font-mono); font-size: 0.92em; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

.wrap {
  width: 100%;
  max-width: 920px;
  margin: 0 auto;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
}

/* Masthead */
.masthead { background: var(--paper); border-bottom: 1px solid var(--rule); }
.masthead-inner {
  display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between;
  gap: 16px 32px; padding-block: 28px 12px;
}
.brand { display: flex; align-items: center; gap: 14px; min-width: 0; }
.mark { width: 48px; height: 48px; flex: none; }
.mark-ring { fill: none; stroke: var(--rule); stroke-width: 1.5; }
.mark-arrows line { stroke: var(--theory); stroke-width: 2; stroke-linecap: round; }
.mark-tips circle { fill: var(--theory); }
h1 {
  margin: 0; font: 600 var(--step-3)/1.1 var(--font-display); letter-spacing: -0.01em;
  text-wrap: balance;
}
.tagline { margin: 4px 0 0; color: var(--ink-2); max-width: 46ch; }
.masthead-side { display: grid; gap: 6px; justify-items: end; text-align: right; }
.stats { margin: 0; color: var(--ink-2); font-family: var(--font-mono); font-size: var(--step--1); font-variant-numeric: tabular-nums; }
.stats span + span::before { content: " · "; color: var(--ink-3); }
.links { display: flex; flex-wrap: wrap; gap: 6px 16px; justify-content: flex-end; font-size: var(--step--1); }
.link-button {
  font: inherit; color: var(--accent); background: none; border: 0; padding: 0; cursor: pointer;
  text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2px;
}

.volume { margin: 0; padding-block: 4px 18px; }
.volume svg { display: block; width: 100%; height: 44px; }
.volume figcaption { margin-top: 6px; color: var(--ink-3); font-size: var(--step--1); font-variant-numeric: tabular-nums; }
.volume .bar { fill: var(--bar); }
.volume .bar.latest { fill: var(--accent); }
.volume .baseline { stroke: var(--rule); stroke-width: 1; }

/* Filter bar */
.controls {
  position: sticky; top: env(safe-area-inset-top, 0px); z-index: 5;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: saturate(1.2) blur(6px);
  border-bottom: 1px solid var(--rule);
}
body::before {
  content: ""; position: fixed; inset: 0 0 auto; height: env(safe-area-inset-top, 0px);
  z-index: 10; background: var(--bg);
}
.controls-inner { display: grid; gap: 10px; padding-block: 12px; }
.control-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: end; }
.search { flex: 1 1 260px; min-width: 0; }
input[type="search"], select {
  width: 100%; font: inherit; color: var(--ink); background: var(--paper);
  border: 1px solid var(--rule); border-radius: 6px; padding: 7px 10px;
}
input[type="search"]::placeholder { color: var(--ink-3); }
.select { display: grid; gap: 2px; flex: 0 1 auto; }
.select span { font-size: 0.6875rem; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-3); }

.chip-groups { display: flex; flex-wrap: wrap; gap: 8px 18px; }
.chip-group { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.chip-group-label {
  font-size: 0.6875rem; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-3);
  margin-right: 2px;
}
.chip {
  font: 500 var(--step--1)/1.2 var(--font-body); cursor: pointer;
  display: inline-flex; align-items: center; gap: 6px;
  padding: 5px 10px; border-radius: 999px; border: 1px solid var(--rule);
  background: var(--paper); color: var(--ink-2);
}
.chip .n { font-family: var(--font-mono); font-size: 0.75rem; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.chip[data-family="theory"][aria-pressed="true"] { background: var(--theory-soft); border-color: var(--theory); color: var(--theory); }
.chip[data-family="recovery"][aria-pressed="true"] { background: var(--recovery-soft); border-color: var(--recovery); color: var(--recovery); }
.chip[data-family="broader"][aria-pressed="true"] { background: var(--broader-soft); border-color: var(--broader); color: var(--broader); }
.chip[aria-pressed="true"] .n { color: inherit; }
.status { margin: 0; color: var(--ink-2); font-size: var(--step--1); }
.status button { font: inherit; }

/* Paper list */
.list { display: grid; gap: 4px; padding-block: 8px 24px; }
.day {
  display: flex; align-items: baseline; justify-content: space-between; gap: 12px;
  margin: 28px 0 6px; padding-bottom: 6px; border-bottom: 1px solid var(--ink);
  font: 600 var(--step-1)/1.3 var(--font-display);
}
.day .count { font: 400 var(--step--1) var(--font-mono); color: var(--ink-3); font-variant-numeric: tabular-nums; }
.paper {
  display: grid; gap: 6px; padding: 16px 0 18px; border-bottom: 1px solid var(--rule); min-width: 0;
}
.paper-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 10px; font-size: var(--step--1); color: var(--ink-3); }
.arxiv-id { font-family: var(--font-mono); color: var(--ink-2); }
.tag {
  font-size: 0.75rem; padding: 1px 8px; border-radius: 999px; line-height: 1.6;
}
.tag[data-family="theory"] { background: var(--theory-soft); color: var(--theory); }
.tag[data-family="recovery"] { background: var(--recovery-soft); color: var(--recovery); }
.tag[data-family="broader"] { background: var(--broader-soft); color: var(--broader); }
.paper-title { margin: 0; font: 600 var(--step-1)/1.35 var(--font-display); text-wrap: balance; }
.paper-title a { color: var(--ink); text-decoration: none; }
.paper-title a:hover { color: var(--accent); text-decoration: underline; }
.authors { margin: 0; color: var(--ink-2); font-size: var(--step--1); }
.summary { margin: 0; max-width: var(--measure); }
.summary .label {
  font-size: 0.6875rem; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-3); margin-right: 6px;
}
.abstract { margin: 0; max-width: var(--measure); color: var(--ink-2); }
.comment { margin: 0; font-size: var(--step--1); color: var(--ink-3); max-width: var(--measure); }
.actions { display: flex; flex-wrap: wrap; gap: 4px 16px; font-size: var(--step--1); }
.text-button {
  font: inherit; color: var(--accent); background: none; border: 0; padding: 0; cursor: pointer;
  text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2px;
}
.bibtex {
  margin: 4px 0 0; padding: 10px 12px; overflow-x: auto; max-width: 100%;
  font: 400 0.75rem/1.5 var(--font-mono); background: var(--paper); border: 1px solid var(--rule); border-radius: 6px;
  white-space: pre;
}
.empty { padding: 40px 0; color: var(--ink-2); text-align: center; }
.more-row { display: flex; justify-content: center; padding-bottom: 32px; }
.more {
  font: 500 var(--step-0) var(--font-body); cursor: pointer; color: var(--ink);
  background: var(--paper); border: 1px solid var(--rule); border-radius: 6px; padding: 9px 18px;
}
.more:hover { border-color: var(--ink-3); }

.footer { padding-block: 24px 40px; border-top: 1px solid var(--rule); color: var(--ink-3); font-size: var(--step--1); }
.footer p { margin: 0 0 8px; max-width: var(--measure); }

@media (max-width: 640px) {
  h1 { font-size: var(--step-2); }
  .masthead-side { justify-items: start; text-align: left; }
  .links { justify-content: flex-start; }
  .select { flex: 1 1 140px; }
}
@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; transition: none !important; }
}

/* View tabs */
.views { display: flex; gap: 4px; padding-block: 2px 14px; }
.view-tab {
  font: 500 var(--step-0) var(--font-body); cursor: pointer; color: var(--ink-2);
  background: none; border: 0; border-bottom: 2px solid transparent; padding: 6px 10px 6px 0; margin-right: 14px;
  display: inline-flex; align-items: baseline; gap: 6px;
}
.view-tab .n { font: 400 0.75rem var(--font-mono); color: var(--ink-3); font-variant-numeric: tabular-nums; }
.view-tab[aria-pressed="true"] { color: var(--ink); border-bottom-color: var(--accent); }
.view-tab:hover { color: var(--ink); }

/* Reading list */
.reading { padding-block: 24px 32px; }
.reading-intro { margin: 0 0 16px; color: var(--ink-2); max-width: var(--measure); }
.toc { display: flex; flex-wrap: wrap; gap: 6px 14px; padding-bottom: 8px; font-size: var(--step--1); }
.reading-section { padding-top: 12px; }
.reading-section h2 {
  margin: 24px 0 2px; padding-bottom: 6px; border-bottom: 1px solid var(--ink);
  display: flex; align-items: baseline; justify-content: space-between; gap: 12px;
  font: 600 var(--step-1)/1.3 var(--font-display);
}
.reading-section h2 .count { font: 400 var(--step--1) var(--font-mono); color: var(--ink-3); font-variant-numeric: tabular-nums; }
.reading-section .section-description { margin: 6px 0 4px; color: var(--ink-3); font-size: var(--step--1); }
.entries { list-style: none; margin: 0; padding: 0; }
.entry { display: grid; gap: 3px; padding: 12px 0; border-bottom: 1px solid var(--rule); min-width: 0; }
.entry-title { font: 600 var(--step-0)/1.4 var(--font-display); }
.entry-title a { color: var(--ink); text-decoration: none; }
.entry-title a:hover { color: var(--accent); text-decoration: underline; }
.entry-meta { color: var(--ink-3); font-size: var(--step--1); }
.entry-note { margin: 0; color: var(--ink-2); max-width: var(--measure); }

/* Hero */
.masthead {
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 28px 28px;
  background-position: -1px -1px;
}
.hero {
  display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  gap: 40px; align-items: center; padding-block: 44px 26px;
}
.hero-text { min-width: 0; }
.eyebrow {
  display: flex; align-items: center; gap: 10px; margin: 0 0 14px;
  font: 500 0.75rem var(--font-mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-2);
}
.eyebrow .mark { width: 28px; height: 28px; }
.hero h1 { font: 600 clamp(2.4rem, 5.2vw, 3.7rem)/1.02 var(--font-display); letter-spacing: -0.02em; }
.lede { margin: 16px 0 14px; font-size: var(--step-1); line-height: 1.55; color: var(--ink-2); max-width: 32em; }
.hero .stats { margin: 0; }
.cta { display: flex; flex-wrap: wrap; gap: 10px; margin: 20px 0 14px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; cursor: pointer; text-decoration: none;
  font: 500 var(--step-0)/1.2 var(--font-body); color: var(--ink);
  padding: 10px 16px; border-radius: 8px; border: 1px solid var(--rule-strong); background: var(--paper);
}
.btn:hover { border-color: var(--ink-3); text-decoration: none; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btn.primary:hover { filter: brightness(1.07); }
.btn.ghost { background: transparent; }
.btn.small { padding: 6px 12px; font-size: var(--step--1); }
.hero .links { justify-content: flex-start; }

.toy-card {
  margin: 0; display: grid; gap: 12px; min-width: 0;
  background: var(--paper); border: 1px solid var(--rule); border-radius: 14px; padding: 16px;
  box-shadow: 0 18px 40px -24px var(--shadow);
}
.toy-stage { position: relative; }
#toy-canvas { display: block; width: 100%; max-width: 100%; aspect-ratio: 1 / 1; }
.toy-readout {
  position: absolute; left: 4px; top: 2px; margin: 0; display: flex; gap: 10px;
  font: 500 0.75rem var(--font-mono); color: var(--ink-2); font-variant-numeric: tabular-nums;
}
.toy-readout #toy-step { color: var(--ink-3); }
.toy-card figcaption { color: var(--ink-2); font-size: var(--step--1); line-height: 1.55; }
.toy-card figcaption strong { color: var(--ink); }
.toy-controls { display: flex; flex-wrap: wrap; gap: 12px 16px; align-items: end; }
.toy-slider { flex: 1 1 200px; display: grid; gap: 4px; font-size: var(--step--1); color: var(--ink-2); min-width: 0; }
.toy-slider output { font-family: var(--font-mono); color: var(--ink); margin-left: 6px; }
.toy-slider input[type="range"] { width: 100%; accent-color: var(--accent); }
.toy-slider .scale { display: flex; justify-content: space-between; font-size: 0.6875rem; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-3); }
.toy-n select { width: auto; }

/* The film: a poster that becomes the player on press */
.film { padding-block: 0 26px; }
.film-card {
  display: grid; grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr); gap: 22px; align-items: center;
  background: var(--paper); border: 1px solid var(--rule); border-radius: 14px; padding: 14px;
  box-shadow: 0 18px 40px -24px var(--shadow);
}
.film-stage { position: relative; aspect-ratio: 16 / 9; border-radius: 9px; overflow: hidden; background: #0e1116; }
.film-player { position: absolute; inset: 0; display: block; }
.film-player img { display: block; width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s ease; }
.film-player:hover img { transform: scale(1.015); }
.film-play {
  position: absolute; left: 16px; bottom: 16px; width: 56px; height: 56px; border-radius: 50%;
  display: grid; place-items: center; background: var(--accent); color: var(--on-accent);
  box-shadow: 0 10px 26px -10px var(--shadow);
}
.film-play svg { width: 24px; height: 24px; fill: currentColor; margin-left: 3px; }
.film-player:hover .film-play { filter: brightness(1.08); }
.film-frame { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.film-text { min-width: 0; padding-right: 6px; }
.film-text .kicker { margin: 0 0 6px; }
.film-text h2 { margin: 0 0 8px; font: 600 var(--step-2)/1.15 var(--font-display); letter-spacing: -0.01em; }
.film-text p { margin: 0 0 12px; color: var(--ink-2); font-size: var(--step--1); line-height: 1.55; }
.film-chapters {
  list-style: none; margin: 0; padding: 0; display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 14px; font-size: var(--step--1);
}
.film-chapters a { display: flex; gap: 8px; padding: 5px 0; color: var(--ink); text-decoration: none; }
.film-chapters a:hover { color: var(--accent); }
.film-chapters span { min-width: 2.7em; font-family: var(--font-mono); color: var(--ink-3); font-variant-numeric: tabular-nums; }
@media (max-width: 820px) {
  .film-card { grid-template-columns: 1fr; gap: 14px; }
  .film-text { padding: 0 2px 4px; }
  .film-chapters a { padding: 10px 0; }
}
@media (prefers-reduced-motion: reduce) { .film-player img { transition: none; } }

/* Highlights */
.highlights-wrap { padding-block: 18px 2px; }
.highlights-wrap .volume { padding-block: 0 6px; }
.kicker {
  margin: 18px 0 10px; font: 500 0.75rem var(--font-mono); letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--ink-3);
}
.highlights { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.hl-card {
  display: grid; gap: 6px; align-content: start; min-width: 0;
  background: var(--paper); border: 1px solid var(--rule); border-radius: 12px; padding: 14px 16px;
}
.hl-card .hl-tags { display: flex; flex-wrap: wrap; gap: 4px; }
.hl-card .hl-title { font: 600 var(--step-0)/1.35 var(--font-display); }
.hl-card .hl-title a { color: var(--ink); text-decoration: none; }
.hl-card .hl-title a:hover { color: var(--accent); text-decoration: underline; }
.hl-card .hl-meta { color: var(--ink-3); font-size: var(--step--1); }

@media (max-width: 820px) {
  .hero { grid-template-columns: 1fr; gap: 28px; padding-block: 32px 18px; }
  .highlights { grid-template-columns: 1fr; }
}

.stats { display: flex; flex-wrap: wrap; }
.stats span { white-space: nowrap; }
.stats span + span::before { content: "\00B7"; margin: 0 0.55em; }