/* =========================================================================
   The Comprehensive Guide to Effect — editorial theme
   Warm paper, terracotta accent, serif display, dark code.
   ========================================================================= */

:root {
  --paper:      #faf6ef;
  --paper-2:    #f3ece0;
  --paper-3:    #ece2d3;
  --ink:        #2b2420;
  --ink-soft:   #4a3f37;
  --muted:      #756a5d;
  --line:       rgba(43, 36, 32, 0.12);
  --line-2:     rgba(43, 36, 32, 0.07);

  --terra:      #c0552b;
  --terra-dk:   #9f4420;
  --amber:      #dca049;
  --green:      #4f7a52;
  --green-dk:   #3c6440;
  --brick:      #b14d3c;

  --code-bg:    #26221e;
  --code-bg-2:  #2f2a25;
  --code-ink:   #e9e1d4;

  --serif: "Fraunces", Georgia, "Times New Roman", serif;
  --sans:  "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono:  "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;

  --maxw: 1080px;
  --readw: 720px;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(43,36,32,.05), 0 8px 30px rgba(43,36,32,.07);

  color-scheme: light;
}

/* ---------------------------------------------------------- dark theme ---
   A complement to the light editorial theme, not a different design:
   the same terracotta accent and warm tone, on espresso-dark surfaces.
   Hand-drawn diagram cards (.figcard) and the hero banner stay on warm
   light paper — the SVGs are drawn against it — so they read as inset
   illustration cards on the dark page. */
[data-theme="dark"] {
  --paper:      #1b1815;
  --paper-2:    #242019;
  --paper-3:    #2c2722;
  --ink:        #ece3d6;
  --ink-soft:   #c8bcab;
  --muted:      #998c7b;
  --line:       rgba(236, 227, 214, 0.14);
  --line-2:     rgba(236, 227, 214, 0.07);

  --terra:      #d06a3f;
  --terra-dk:   #e6976f;   /* links & accents — lifted for the dark surface */
  --amber:      #e3a851;
  --green:      #84ac68;
  --green-dk:   #9dc282;
  --brick:      #cd6f5b;

  --shadow: 0 1px 2px rgba(0,0,0,.30), 0 10px 34px rgba(0,0,0,.40);

  color-scheme: dark;
}

/* surfaces that carry a hardcoded light fill → dark equivalents */
[data-theme="dark"] .site-header { background: rgba(27, 24, 21, .82); }
[data-theme="dark"] pre { border-color: rgba(255,255,255,.08); }
[data-theme="dark"] .part-card,
[data-theme="dark"] .sec-item,
[data-theme="dark"] .pager a,
[data-theme="dark"] .stepper { background: linear-gradient(180deg, #262119, #211d17); }
[data-theme="dark"] .stepper-bar { background: rgba(255,255,255,.03); }
[data-theme="dark"] .stepper-btn { background: #2c2722; color: var(--ink); }
[data-theme="dark"] .secpills a,
[data-theme="dark"] .repo-files a { background: rgba(255,255,255,.04); }
[data-theme="dark"] .callout.note { background: #2a2316; }
[data-theme="dark"] .callout.real { background: #1f261c; }
[data-theme="dark"] .callout.repo { background: #262019; }
/* diagram cards + banner stay on warm paper (SVGs drawn for it), but
   softened to a muted paper so they don't glare against the dark page */
[data-theme="dark"] .figcard { background: linear-gradient(180deg, #f3ece0, #e8dece); border-color: rgba(0,0,0,.18); }
[data-theme="dark"] .banner  { background: linear-gradient(180deg, #f4ebda, #e9dcc4); border-color: rgba(0,0,0,.18); }
[data-theme="dark"] .banner .tagline { color: #2b2420; }

/* smooth the switch on the surfaces that change */
body, .site-header, .callout, .part-card, .sec-item, .toc,
.pager a, .stepper, .secpills a, pre, .theme-toggle {
  transition: background-color .2s ease, border-color .2s ease, color .15s ease;
}

/* theme toggle button */
.theme-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: 9px; padding: 0;
  border: 1px solid var(--line); background: rgba(255,255,255,.45);
  color: var(--ink-soft); cursor: pointer;
}
.theme-toggle:hover { border-color: var(--terra); color: var(--terra-dk); }
.theme-toggle svg { width: 17px; height: 17px; }
[data-theme="dark"] .theme-toggle { background: rgba(255,255,255,.05); }
.theme-toggle .ic-sun { display: none; }
[data-theme="dark"] .theme-toggle .ic-moon { display: none; }
[data-theme="dark"] .theme-toggle .ic-sun { display: block; }

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 18px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* subtle paper grain via layered gradients */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(220,160,73,.10), transparent 60%),
    radial-gradient(900px 500px at -10% 0%, rgba(192,85,43,.07), transparent 55%);
  pointer-events: none;
}

::selection { background: rgba(192,85,43,.20); }

a { color: var(--terra-dk); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

/* ----------------------------------------------------------------- header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(10px);
  background: rgba(250,246,239,.82);
  border-bottom: 1px solid var(--line);
}
.site-header .inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 18px;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  font-family: var(--serif);
  font-weight: 600;
  font-size: 17px;
  color: var(--ink);
}
.brand:hover { text-decoration: none; }
.brand .glyph { width: 26px; height: 26px; display: block; }
.nav { margin-left: auto; display: flex; gap: 22px; align-items: center; }
.nav a {
  color: var(--ink-soft);
  font-size: 15px;
  font-weight: 500;
}
.nav a.active { color: var(--terra-dk); }
@media (max-width: 640px) {
  .nav { gap: 14px; }
  .nav a.hide-sm { display: none; }
}

/* ----------------------------------------------------------------- layout */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
main { padding-bottom: 96px; }

.reading { max-width: var(--readw); margin: 0 auto; }
.reading.wide { max-width: 920px; }

/* prose rhythm */
.prose > * { max-width: var(--readw); margin-left: auto; margin-right: auto; }
.prose > .full,
.prose > figure,
.prose > .compare,
.prose > .stepper,
.prose > .grid-cards { max-width: 920px; }

.prose p, .prose ul, .prose ol { margin: 1.1em auto; }
.prose li { margin: .4em 0; }
.prose ul, .prose ol { padding-left: 1.3em; }
.prose strong { font-weight: 650; color: var(--ink); }
.prose em { font-style: italic; }

h1, h2, h3, h4 { font-family: var(--serif); color: var(--ink); line-height: 1.18; font-weight: 600; }
h2 {
  font-size: 30px;
  margin: 2.4em auto .6em;
  letter-spacing: -.01em;
}
h2::before {
  content: "";
  display: block;
  width: 38px; height: 3px;
  background: var(--terra);
  border-radius: 2px;
  margin-bottom: .5em;
}
h3 { font-size: 22px; margin: 1.8em auto .4em; }
h4 { font-size: 18px; margin: 1.5em auto .3em; font-family: var(--sans); font-weight: 700; }

.lead { font-size: 21px; color: var(--ink-soft); line-height: 1.6; }

.eyebrow {
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--terra-dk);
  font-weight: 600;
}

hr { border: 0; border-top: 1px solid var(--line); margin: 3em auto; max-width: var(--readw); }

/* ------------------------------------------------------------------- hero */
.hero {
  position: relative;
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}
.hero .wrap { padding-top: 64px; padding-bottom: 56px; }
.hero .eyebrow { margin-bottom: 18px; }
.hero h1 {
  font-size: clamp(40px, 6vw, 68px);
  line-height: 1.04;
  letter-spacing: -.025em;
  margin: 0 0 .35em;
  max-width: 16ch;
}
.hero h1 .accent { color: var(--terra); }
.hero .sub {
  font-size: 20px;
  color: var(--ink-soft);
  max-width: 56ch;
  margin: 0;
}
.hero-art { margin-top: 40px; }

/* banner ribbon */
.banner {
  margin-top: 38px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background:
    linear-gradient(180deg, #fff8ec 0%, #f6ecdb 100%);
  box-shadow: var(--shadow);
  padding: 30px 32px;
  display: flex;
  align-items: center;
  gap: 28px;
  flex-wrap: wrap;
}
.banner .tagline {
  font-family: var(--serif);
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1.15;
  font-weight: 600;
  letter-spacing: -.01em;
  margin: 0;
  flex: 1 1 320px;
}
.banner .tagline .hl { color: var(--terra); }

/* ------------------------------------------------------------- code blocks */
pre {
  background: var(--code-bg);
  color: var(--code-ink);
  border-radius: 12px;
  padding: 18px 20px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 14.5px;
  line-height: 1.6;
  margin: 1.5em auto;
  box-shadow: var(--shadow);
  border: 1px solid rgba(0,0,0,.25);
}
pre code { font-family: inherit; padding: 0; background: none; }

:not(pre) > code {
  font-family: var(--mono);
  font-size: .88em;
  background: var(--paper-3);
  border: 1px solid var(--line-2);
  padding: .08em .4em;
  border-radius: 6px;
  color: var(--terra-dk);
}

/* code caption / filename pill */
.code-label {
  display: inline-block;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  margin: 1.5em auto -.6em;
  padding-left: 2px;
}

/* highlight.js token theme (warm) */
.hljs-comment, .hljs-quote { color: #8a7f6f; font-style: italic; }
.hljs-keyword, .hljs-selector-tag, .hljs-built_in.hljs-keyword { color: #e0936a; }
.hljs-string, .hljs-template-string, .hljs-regexp { color: #a7c08a; }
.hljs-number, .hljs-literal { color: #d9a85c; }
.hljs-title, .hljs-title.function_, .hljs-function .hljs-title { color: #ecc97f; }
.hljs-title.class_, .hljs-type, .hljs-built_in { color: #e7b98c; }
.hljs-attr, .hljs-property, .hljs-attribute { color: #d8cdbb; }
.hljs-params { color: #e9e1d4; }
.hljs-meta, .hljs-symbol, .hljs-tag { color: #c9bca8; }
.hljs-punctuation { color: #c1b4a0; }
.hljs-operator { color: #e0936a; }

/* --------------------------------------------------------------- compare */
.compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  margin: 1.8em auto;
  align-items: start;
}
.compare .pane { border-radius: 12px; overflow: hidden; border: 1px solid var(--line); background: var(--code-bg); box-shadow: var(--shadow); }
.compare .pane > pre { margin: 0; border-radius: 0; box-shadow: none; border: 0; }
.compare .pane-head {
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: .04em;
  padding: 9px 16px;
  color: #fff;
  display: flex; align-items: center; gap: 8px;
}
.pane.bad .pane-head  { background: var(--brick); }
.pane.good .pane-head { background: var(--green); }
.pane-head .dot { width: 8px; height: 8px; border-radius: 50%; background: rgba(255,255,255,.85); }
@media (max-width: 760px) { .compare { grid-template-columns: 1fr; } }

/* --------------------------------------------------------------- callouts */
.callout {
  border-radius: 12px;
  padding: 18px 22px;
  margin: 1.8em auto;
  border: 1px solid var(--line);
  background: var(--paper-2);
  font-size: 16.5px;
}
.callout .tag {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  text-transform: uppercase;
  font-weight: 600;
  display: block;
  margin-bottom: 6px;
}
.callout p:first-of-type { margin-top: 0; }
.callout p:last-child { margin-bottom: 0; }
.callout.why    { border-left: 4px solid var(--terra); }
.callout.why .tag { color: var(--terra-dk); }
.callout.note   { border-left: 4px solid var(--amber); background: #fbf3e2; }
.callout.note .tag { color: #a9772a; }
.callout.real   { border-left: 4px solid var(--green); background: #eef3ea; }
.callout.real .tag { color: var(--green-dk); }
.callout.key    { border-left: 4px solid var(--ink); background: var(--paper-3); }
.callout.key .tag { color: var(--ink); }

/* big takeaway line */
.takeaway {
  font-family: var(--serif);
  font-size: 23px;
  line-height: 1.4;
  color: var(--ink);
  border-left: 3px solid var(--terra);
  padding: 6px 0 6px 22px;
  margin: 1.8em auto;
  font-weight: 500;
}

/* ----------------------------------------------------------------- figures */
figure { margin: 2em auto; }
figure svg { display: block; width: 100%; height: auto; }
.figcard {
  background: #fff;
  background: linear-gradient(180deg, #fffdf8, #faf4e9);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 28px;
  box-shadow: var(--shadow);
}
figcaption {
  font-size: 14.5px;
  color: var(--muted);
  text-align: center;
  margin-top: 14px;
  font-style: italic;
}

/* ----------------------------------------------------------- part cards */
.grid-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; margin: 2.2em auto; }
@media (max-width: 760px) { .grid-cards { grid-template-columns: 1fr; } }
.part-card {
  display: block;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, #fffdf8, #f6efe2);
  padding: 28px 28px 26px;
  box-shadow: var(--shadow);
  color: var(--ink);
  transition: transform .15s ease, box-shadow .15s ease, border-color .15s;
}
.part-card:hover {
  text-decoration: none;
  transform: translateY(-3px);
  box-shadow: 0 2px 4px rgba(43,36,32,.06), 0 16px 40px rgba(43,36,32,.12);
  border-color: rgba(192,85,43,.4);
}
.part-card .num {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--terra-dk);
  font-weight: 600;
}
.part-card h3 { margin: .25em 0 .35em; font-size: 25px; }
.part-card p { margin: 0; color: var(--ink-soft); font-size: 16px; }
.part-card { display: flex; flex-direction: column; }
.part-card .go { margin-top: auto; padding-top: 16px; font-weight: 600; color: var(--terra-dk); font-size: 15px; display: inline-flex; gap: 6px; align-items: center; }
.part-card:hover .go .arr { transform: translateX(4px); }
.part-card .go .arr { transition: transform .15s; }

/* section index list (part 2) */
.sec-list { display: grid; gap: 14px; margin: 2em auto; max-width: 760px; }
.sec-item {
  display: flex; gap: 18px; align-items: flex-start;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, #fffdf8, #f7f0e4);
  border-radius: 12px;
  padding: 18px 22px;
  color: var(--ink);
  transition: transform .12s ease, border-color .12s, box-shadow .12s;
  box-shadow: 0 1px 2px rgba(43,36,32,.04);
}
.sec-item:hover { text-decoration: none; transform: translateX(3px); border-color: rgba(192,85,43,.4); box-shadow: var(--shadow); }
.sec-item .badge {
  flex: none;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 15px;
  color: #fff;
  background: var(--terra);
  width: 46px; height: 46px;
  border-radius: 11px;
  display: grid; place-items: center;
}
.sec-item h4 { margin: 0 0 2px; font-family: var(--sans); font-size: 18px; }
.sec-item p { margin: 0; color: var(--muted); font-size: 15px; }
.sec-item .methods { font-family: var(--mono); font-size: 12.5px; color: var(--terra-dk); margin-top: 4px; }

/* --------------------------------------------------------------- stepper */
.stepper {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, #fffdf8, #f6efe2);
  box-shadow: var(--shadow);
  padding: 0;
  overflow: hidden;
  margin: 2em auto;
}
.stepper-bar {
  display: flex; align-items: center; gap: 14px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--line);
  background: rgba(255,255,255,.5);
}
.stepper-bar .title { font-family: var(--mono); font-size: 12.5px; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); font-weight: 600; }
.stepper-bar .count { font-family: var(--mono); font-size: 13px; color: var(--terra-dk); margin-left: auto; font-weight: 600; }
.stepper-btn {
  font-family: var(--sans); font-weight: 600; font-size: 14px;
  border: 1px solid var(--line); background: #fff; color: var(--ink);
  border-radius: 8px; padding: 6px 14px; cursor: pointer;
  transition: background .12s, border-color .12s;
}
.stepper-btn:hover:not(:disabled) { border-color: var(--terra); color: var(--terra-dk); }
.stepper-btn:disabled { opacity: .4; cursor: default; }
.stepper-body { padding: 20px 22px 24px; }
.stepper-desc { font-size: 16.5px; margin: 0 0 16px; min-height: 3em; }
.stepper-desc .hl { color: var(--terra-dk); font-weight: 600; font-family: var(--mono); font-size: .92em; }
.machine { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
@media (max-width: 620px){ .machine { grid-template-columns: 1fr; } }
.reg {
  background: var(--code-bg);
  border-radius: 10px;
  padding: 12px 14px;
  font-family: var(--mono);
  font-size: 13.5px;
  color: var(--code-ink);
}
.reg .lab { color: #8a7f6f; font-size: 11px; letter-spacing: .1em; text-transform: uppercase; display: block; margin-bottom: 6px; }
.reg .val { color: #ecc97f; font-weight: 500; }
.reg.fail .val { color: #e0936a; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; min-height: 1.6em; }
.chip {
  background: var(--code-bg-2);
  border: 1px solid rgba(255,255,255,.12);
  color: #d8cdbb;
  border-radius: 6px;
  padding: 2px 9px;
  font-size: 12.5px;
}
.chip.top { border-color: var(--terra); color: #f0b48a; }
.chip.dim { opacity: .4; text-decoration: line-through; }
.progress-track { height: 4px; background: var(--paper-3); }
.progress-fill { height: 100%; background: var(--terra); transition: width .2s ease; }

/* small kbd-ish run line */
.runline {
  font-family: var(--mono); font-size: 13.5px;
  background: var(--code-bg); color: #a7c08a;
  border-radius: 8px; padding: 10px 14px; margin: 1.4em auto;
  display: block;
}
.runline::before { content: "$ "; color: #8a7f6f; }

/* footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 40px 24px;
  color: var(--muted);
  font-size: 14.5px;
}
.site-footer .inner { max-width: var(--maxw); margin: 0 auto; display: flex; gap: 16px; flex-wrap: wrap; align-items: center; }
.site-footer .inner .sp { margin-left: auto; }

/* prev/next pager */
.pager { display: flex; gap: 16px; margin: 3.5em auto 0; max-width: var(--readw); }
.pager a {
  flex: 1;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px 20px;
  background: linear-gradient(180deg, #fffdf8, #f6efe2);
  color: var(--ink);
  transition: border-color .12s, transform .12s;
}
.pager a:hover { text-decoration: none; border-color: var(--terra); transform: translateY(-2px); }
.pager .dir { font-family: var(--mono); font-size: 12px; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); }
.pager .ttl { font-weight: 600; color: var(--terra-dk); margin-top: 3px; }
.pager a.next { text-align: right; }

/* breadcrumb */
.crumbs { font-family: var(--mono); font-size: 13px; color: var(--muted); padding-top: 36px; }
.crumbs a { color: var(--muted); }
.crumbs a:hover { color: var(--terra-dk); }

/* table of contents */
main h2 { scroll-margin-top: 84px; }
main h3[id] { scroll-margin-top: 84px; }
.toc {
  border: 1px solid var(--line);
  background: var(--paper-2);
  border-radius: 12px;
  padding: 16px 22px;
  margin: 1.8em auto;
  max-width: var(--readw);
  font-size: 15.5px;
}
.toc-title { font-family: var(--mono); font-size: 11.5px; letter-spacing: .12em; text-transform: uppercase; color: var(--muted); font-weight: 600; margin-bottom: 8px; }
.toc ol { margin: 0; padding-left: 1.3em; }
.toc li { margin: .25em 0; }
.toc a { color: var(--ink-soft); }
.toc a:hover { color: var(--terra-dk); }

/* follow-along (repo) callout */
.callout.repo { border-left: 4px solid var(--ink); background: #f1ece2; }
.callout.repo .tag { color: var(--ink); }
.repo-files { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.repo-files a {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--mono); font-size: 13px;
  border: 1px solid var(--line); background: #fff; color: var(--ink-soft);
  border-radius: 7px; padding: 4px 11px;
}
.repo-files a:hover { text-decoration: none; border-color: var(--terra); color: var(--terra-dk); }
.repo-files a .gh { width: 14px; height: 14px; opacity: .7; }

/* footer extras */
.site-footer a { color: var(--ink-soft); }
.site-footer .love { color: var(--muted); }
.site-footer .love .heart { color: var(--terra); }

/* tables (used in the capstone "needs → built in" map) */
.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.6em auto;
  font-size: 16px;
}
.prose table th, .prose table td {
  text-align: left;
  padding: 10px 14px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
.prose table th {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 600;
}
.prose table td:last-child { color: var(--ink-soft); white-space: nowrap; }
.prose table tr:last-child td { border-bottom: 0; }

/* section pills (2.1–2.7 quick nav) */
.secpills { display: flex; flex-wrap: wrap; gap: 7px; margin: 1.4em auto 0; max-width: var(--readw); }
.secpills a {
  font-family: var(--mono); font-size: 12.5px; font-weight: 600;
  border: 1px solid var(--line); border-radius: 999px;
  padding: 4px 12px; color: var(--ink-soft);
  background: rgba(255,255,255,.5);
}
.secpills a:hover { text-decoration: none; border-color: var(--terra); color: var(--terra-dk); }
.secpills a.active { background: var(--terra); color: #fff; border-color: var(--terra); }

/* diagram helper text inside svg uses these via fill attributes in markup */
.muted { color: var(--muted); }
.center { text-align: center; }