/* Site layer on top of Tufte CSS (tufte.css). Tokens first; components after.
   Rule: color carries meaning. --accent marks what the reader manipulates or the
   first of two compared quantities; --second marks the other. Nothing else is colored. */

:root {
  /* Three type sizes only: page title (h1), section heading (h2), and --text for everything else. */
  --text: 16pt;
  --paper: #fffff8;
  --ink: #111111;
  --quiet: #5f5e57;
  --rule: #d9d6c9;
  --faint: #efede2;
  --accent: #2b4fa0;
  --second: #a8690f;
  --good: #3c6e3a;
  --bad: #9e2a20;
  --focus: #2b4fa0;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #161614;
    --ink: #e6e4dc;
    --quiet: #a3a196;
    --rule: #3b3a34;
    --faint: #2c2b27;
    --accent: #8fa8ec;
    --second: #dba64a;
    --good: #8cc488;
    --bad: #e08a80;
    --focus: #8fa8ec;
  }
}
:root[data-theme="dark"] {
  --paper: #161614; --ink: #e6e4dc; --quiet: #a3a196; --rule: #3b3a34; --faint: #2c2b27;
  --accent: #8fa8ec; --second: #dba64a; --good: #8cc488; --bad: #e08a80; --focus: #8fa8ec;
}

body { background-color: var(--paper); color: var(--ink); }
a:link, a:visited { color: inherit; }
::selection { background: var(--faint); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }

/* Numbers in readouts and tables line up. */
.num, .readout, table, .tool output { font-variant-numeric: lining-nums tabular-nums; }

/* Top line: where you are, and the way back to the contents. */
.topline {
  width: 55%; display: flex; justify-content: space-between; align-items: baseline;
  padding-top: 2rem; font-size: var(--text); color: var(--quiet);
}
.topline a { text-decoration: none; background: none; color: var(--quiet); }
.topline a:hover { color: var(--ink); }
.topline .core-dot { margin-left: 0.4rem; }
article { padding-top: 1.5rem; }
h1 { margin-top: 1.5rem; }
h1 .pageno { color: var(--quiet); margin-right: 0.6rem; }

/* Core-path marker: a small filled dot, explained on the contents page. */
.core-dot {
  display: inline-block; width: 0.45rem; height: 0.45rem; border-radius: 50%;
  background: var(--ink); vertical-align: 0.15rem;
}

/* Colored words in prose that name a figure element. */
.c-accent { color: var(--accent); }
.c-second { color: var(--second); }

/* Interactive tool: spans text column and margin. */
.tool { width: 90%; margin: 2rem 0 2.5rem; clear: right; }
figure.multiples, ol.tasks, .check, .explain, .takeaway { clear: right; }
.katex-display { width: 55%; overflow-x: auto; overflow-y: hidden; padding: 0.2rem 0; }
.tool .panel { margin-bottom: 2.2rem; }
.tool h3 { margin-top: 0.4rem; margin-bottom: 0.6rem; font-size: var(--text); }
.tool .panel-note { font-size: var(--text); line-height: 1.5; color: var(--quiet); width: 61%; margin: 0.2rem 0 0.8rem; }
.tool .row { display: flex; flex-wrap: wrap; gap: 1.6rem; align-items: flex-start; }
.tool .controls { display: flex; flex-direction: column; gap: 0.9rem; min-width: 15rem; max-width: 19rem; flex: 0 1 19rem; }
.tool .stage { flex: 1 1 26rem; min-width: 0; }
.tool svg, .tool canvas, figure svg { display: block; max-width: 100%; height: auto; touch-action: none; }
.readout { font-size: var(--text); line-height: 1.5; width: 61%; margin: 0.8rem 0 0; }
.readout b { font-weight: 600; }

/* Controls */
.ctl { display: flex; flex-direction: column; gap: 0.25rem; font-size: var(--text); }
.ctl .ctl-head { display: flex; justify-content: space-between; gap: 1rem; }
.ctl .ctl-head output { color: var(--ink); }
.ctl .ctl-name { color: var(--quiet); }
input[type="range"] {
  -webkit-appearance: none; appearance: none; width: 100%; height: 1.4rem; background: transparent; margin: 0;
}
input[type="range"]::-webkit-slider-runnable-track { height: 1px; background: var(--quiet); }
input[type="range"]::-moz-range-track { height: 1px; background: var(--quiet); }
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; width: 0.95rem; height: 0.95rem; border-radius: 50%;
  background: var(--accent); margin-top: -0.45rem; border: 0;
}
input[type="range"]::-moz-range-thumb { width: 0.95rem; height: 0.95rem; border-radius: 50%; background: var(--accent); border: 0; }

.seg { display: inline-flex; flex-wrap: wrap; gap: 0.35rem; }
button, .seg button {
  font: inherit; font-size: var(--text); color: var(--ink); background: transparent;
  border: 1px solid var(--rule); border-radius: 3px; padding: 0.15rem 0.65rem; cursor: pointer;
}
button:hover { border-color: var(--quiet); }
.seg button[aria-pressed="true"], button.primary { border-color: var(--accent); color: var(--accent); }
button:disabled { opacity: 0.45; cursor: default; }

/* Tasks: predict, then try, then see what to notice. */
ol.tasks { width: 61%; padding-left: 1.4rem; }
ol.tasks > li { margin-bottom: 1.3rem; }
.task .prompt { margin: 0; }
.task .choices { margin: 0.5rem 0 0.2rem; }
.task .choices-label { font-size: var(--text); color: var(--quiet); margin-right: 0.5rem; }
.task .after { display: none; font-size: var(--text); line-height: 1.5; margin-top: 0.4rem; }
.task.predicted .after { display: block; }
.task .notice { display: none; border-left: 2px solid var(--rule); padding-left: 0.8rem; margin-top: 0.5rem; }
.task.revealed .notice { display: block; }
.task button[aria-pressed="true"] { border-color: var(--ink); }

/* Check questions and self-explanation. */
.check, .explain, .takeaway {
  width: 55%; border-top: 1px solid var(--rule); padding-top: 0.8rem; margin-top: 2rem;
}
.check .label, .explain .label, .takeaway .label { font-style: italic; color: var(--quiet); font-size: var(--text); }
.check .q { margin-top: 0.4rem; margin-bottom: 0.6rem; }
.check .feedback { display: none; margin-top: 0.7rem; }
.check.answered .feedback { display: block; }
.check .verdict-right { color: var(--good); }
.check .verdict-wrong { color: var(--bad); }
.check button.chosen { border-color: var(--ink); }
.explain textarea {
  width: 100%; min-height: 4.5rem; font: inherit; font-size: var(--text); line-height: 1.5;
  color: var(--ink); background: transparent; border: 1px solid var(--rule); border-radius: 3px; padding: 0.4rem 0.5rem;
}
.explain .saved { font-size: var(--text); color: var(--quiet); }
.takeaway p { margin-top: 0.4rem; }

/* Page-end navigation. */
.pagenav { width: 55%; display: flex; justify-content: space-between; gap: 2rem; margin: 3rem 0 4rem; font-size: var(--text); }
.pagenav a { text-decoration: none; background: none; }
.pagenav a:hover { text-decoration: underline; }
.pagenav .dir { display: block; color: var(--quiet); font-size: var(--text); }
.pagenav .next { text-align: right; }

/* Charts: no frames or grids; quiet axes; labels on the lines. */
.chart text { font-family: et-book, Georgia, serif; fill: var(--quiet); font-size: var(--text); font-variant-numeric: lining-nums tabular-nums; }
.chart .axis path, .chart .axis line { stroke: var(--rule); }
.chart .label-ink { fill: var(--ink); }
.chart .label-accent { fill: var(--accent); }
.chart .label-second { fill: var(--second); }
figure.multiples { display: flex; flex-wrap: wrap; gap: 1.2rem; max-width: 90%; }
figure.multiples > div { flex: 1 1 12rem; min-width: 11rem; }
figure .small-title { font-size: var(--text); color: var(--ink); margin: 0 0 0.2rem; }

/* Figure captions and claim-type labels. */
.caption { width: 61%; color: var(--quiet); font-size: var(--text); line-height: 1.5; }
.claim { font-style: italic; color: var(--quiet); font-size: var(--text); margin-right: 0.3rem; }
.claim::after { content: "."; }

/* Contents page. */
.contents { width: 61%; }
.contents h2 { font-size: 2.2rem; margin-top: 2.2rem; margin-bottom: 0.4rem; }
.contents ol { list-style: none; padding-left: 0; margin: 0; }
.contents li { display: flex; gap: 0.7rem; align-items: baseline; font-size: var(--text); line-height: 1.5; }
.contents .no { color: var(--quiet); min-width: 2.2rem; }
.contents .planned { color: var(--quiet); }
.contents .mark { min-width: 0.8rem; }
.contents .done-dot { display: inline-block; width: 0.45rem; height: 0.45rem; border-radius: 50%; border: 1px solid var(--quiet); }
.contents .done-dot.done { background: var(--quiet); }
.contents li a { text-decoration: none; background: none; }
.contents li a:hover { text-decoration: underline; }

/* Phones: the tool and its text take the full column. */
@media (max-width: 760px) {
  .katex-display, .topline, .tool, ol.tasks, .readout, .check, .explain, .takeaway, .pagenav, .contents, .tool .panel-note, .caption { width: 100%; }
  .tool .controls { max-width: none; flex: 1 1 100%; }
  ol.tasks { padding-left: 1.2rem; }
}
@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; }
}

/* One text size for everything below the two heading levels, including Tufte CSS defaults,
   sidenotes, formulas, and chart labels. Gray and italics carry the remaining distinctions. */
p, dl, ol, ul, li, blockquote, table, label, input, textarea, button, figcaption, code,
.sidenote, .marginnote, p.subtitle, h3, .tool h3, .katex, .katex-display > .katex {
  font-size: var(--text);
}
p, dl, ol, ul, .sidenote, .marginnote { line-height: 1.5; }
.sidenote, .marginnote { vertical-align: baseline; }
.sidenote-number::after, .sidenote::before { font-size: 0.75em; }

/* Sidenote numbers come from site.js (data-n), not the CSS counter. */
.sidenote-number[data-n]::after { content: attr(data-n); }
.sidenote[data-n]::before { content: attr(data-n) " "; }
/* Long single words in titles must not overflow on phones. */
h1 { hyphens: auto; overflow-wrap: break-word; }
.topline { flex-wrap: wrap; column-gap: 1.2rem; }
/* A page's own canvas cap (e.g. .plane) wins over the generic max-width. */
.tool .plane { max-width: 34rem; }