/* circangle.com */
@font-face { font-family: "LMR"; src: url("lmroman-regular.woff2") format("woff2"); font-weight: 400; font-style: normal; font-display: swap; }
@font-face { font-family: "LMR"; src: url("lmroman-italic.woff2") format("woff2"); font-weight: 400; font-style: italic; font-display: swap; }
@font-face { font-family: "LMR"; src: url("lmroman-bold.woff2") format("woff2"); font-weight: 700; font-style: normal; font-display: swap; }
@font-face { font-family: "LMR"; src: url("lm-math-sub.woff2") format("woff2"); unicode-range: U+03C0, U+2248, U+2264-2265; font-display: swap; }
@font-face { font-family: "LMR"; src: url("lm-math-sub.woff2") format("woff2"); font-style: italic; unicode-range: U+03C0, U+2248, U+2264-2265; font-display: swap; }
@font-face { font-family: "LMR17"; src: url("lmroman17-regular.woff2") format("woff2"); font-display: swap; }
@font-face { font-family: "LMR17"; src: url("lm-math-sub.woff2") format("woff2"); unicode-range: U+03C0; font-display: swap; }
@font-face { font-family: "LMCaps"; src: url("lmroman-caps.woff2") format("woff2"); font-display: swap; }

:root {
  --bg: #0d1b2a;
  --bg-2: #12243a;
  --panel: #152a42;
  --line: #24405f;
  --ink: #eef1f5;
  --ink-2: #c5cfdb;
  --ink-3: #8fa2b8;
  --accent: #f4a261;
  --accent-2: #48cae4;
  --leg-a: #f4a261;
  --leg-b: #7fd18b;
  --arc: #8ecbff;
  --focus: #e07bd0;
  --radius: 10px;
  --max: 1080px;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font-family: "LMR", "Latin Modern Roman", "Computer Modern Serif", Georgia, serif;
  font-size: 19px; line-height: 1.6;
  text-rendering: optimizeLegibility;
}
a { color: var(--accent-2); text-underline-offset: 3px; }
a:hover { color: #8fe3f3; }
img { max-width: 100%; display: block; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 20px; }
.caps { font-family: "LMCaps", "LMR", serif; letter-spacing: .08em; }
h1, h2, h3 { font-weight: 400; line-height: 1.2; margin: 0 0 .5em; }
h2 { font-family: "LMR17", "LMR", serif; font-size: clamp(28px, 4vw, 38px); }
h3 { font-size: 22px; }
p { margin: 0 0 1em; }
.muted { color: var(--ink-3); }
.small { font-size: 15px; }

/* header */
.site-head { position: sticky; top: 0; z-index: 10; background: rgba(13,27,42,.92); backdrop-filter: blur(6px); border-bottom: 1px solid var(--line); }
.site-head .wrap { display: flex; align-items: center; gap: 18px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; }
.brand img { height: 30px; width: auto; }
.brand span { font-family: "LMCaps", serif; letter-spacing: .12em; font-size: 17px; }
.nav { margin-left: auto; display: flex; gap: 20px; font-size: 16px; }
.nav a { color: var(--ink-2); text-decoration: none; }
.nav a:hover, .nav a[aria-current] { color: var(--ink); }
@media (max-width: 640px) {
  .brand span { display: none; }
  .nav { gap: 14px; font-size: 15px; }
}

/* hero */
.hero { padding: 48px 0 40px; }
.hero .wrap { display: grid; grid-template-columns: 1.05fr 1fr; gap: 40px; align-items: center; }
.cover-art { position: relative; width: 100%; aspect-ratio: 1 / 1; }
.cover-art canvas { width: 100%; height: 100%; display: block; }
.hero-title { font-family: "LMR17", serif; font-size: clamp(46px, 8vw, 84px); letter-spacing: .04em; margin: 0; line-height: 1; }
.hero-sub { font-family: "LMR", serif; font-style: italic; color: var(--accent); font-size: clamp(26px, 4vw, 38px); margin: 10px 0 14px; }
.hero-strap { font-family: "LMCaps", serif; letter-spacing: .1em; color: var(--ink-3); font-size: 14px; margin-bottom: 22px; }
.hero-lede { color: var(--ink-2); }
.hero-author { font-family: "LMCaps", serif; letter-spacing: .14em; color: var(--ink-2); margin-top: 18px; font-size: 16px; }
@media (max-width: 860px) {
  .hero { padding-top: 24px; }
  .hero .wrap { grid-template-columns: 1fr; gap: 12px; }
  .cover-art { max-width: 460px; margin: 0 auto; }
}

/* buttons */
.btns { display: flex; flex-wrap: wrap; gap: 10px; }
.btn { display: inline-block; padding: 10px 18px; border-radius: 999px; border: 1px solid var(--line); background: var(--panel); color: var(--ink); text-decoration: none; font-size: 16px; line-height: 1.3; cursor: pointer; font-family: inherit; }
.btn:hover { border-color: var(--accent-2); color: var(--ink); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #1a1209; }
.btn.primary:hover { background: #f7b47f; color: #1a1209; }
.btn small { display: block; font-size: 12px; color: var(--ink-3); }
.btn.primary small { color: #5a3a1c; }

/* sections */
section.band { padding: 64px 0; border-top: 1px solid var(--line); }
section.band.alt { background: var(--bg-2); }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: 44px; align-items: start; }
@media (max-width: 860px) { .two { grid-template-columns: 1fr; gap: 24px; } section.band { padding: 44px 0; } }
.blurb p { color: var(--ink-2); }
.blurb .tag { font-style: italic; color: var(--accent); }
.figure svg { width: 100%; height: auto; display: block; }

/* toy cards */
.cards { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
@media (max-width: 760px) { .cards { grid-template-columns: 1fr; } }
.card { display: block; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; color: var(--ink); text-decoration: none; transition: border-color .15s; }
.card:hover { border-color: var(--accent-2); color: var(--ink); }
.card canvas { width: 100%; height: 180px; display: block; margin-bottom: 14px; }
.card p { color: var(--ink-2); margin: 0; }
.card .go { color: var(--accent-2); margin-top: 10px; display: inline-block; }

/* contents */
.parts { list-style: none; padding: 0; margin: 0; counter-reset: part; display: grid; grid-template-columns: 1fr 1fr; gap: 14px 36px; }
.parts li { counter-increment: part; padding-left: 52px; position: relative; color: var(--ink-2); }
.parts li::before { content: counter(part); position: absolute; left: 0; top: -4px; font-family: "LMR17", serif; font-size: 34px; color: var(--accent); width: 40px; text-align: center; }
.parts b { font-weight: 400; color: var(--ink); display: block; }
@media (max-width: 760px) { .parts { grid-template-columns: 1fr; } }
.specs { margin-top: 28px; color: var(--ink-3); font-size: 16px; }

/* buy */
.store-pick { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-bottom: 18px; font-size: 16px; }
select { font: inherit; font-size: 16px; background: var(--panel); color: var(--ink); border: 1px solid var(--line); border-radius: 8px; padding: 6px 10px; }
.formats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
@media (max-width: 760px) { .formats { grid-template-columns: 1fr; } }
.format { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; display: flex; flex-direction: column; gap: 8px; }
.format h3 { margin: 0; }
.format p { color: var(--ink-2); font-size: 16px; margin: 0 0 8px; flex: 1; }

/* footer */
.site-foot { border-top: 1px solid var(--line); padding: 36px 0 48px; color: var(--ink-3); font-size: 15px; }
.site-foot .wrap { display: flex; flex-wrap: wrap; gap: 14px 28px; align-items: center; }
.site-foot img { height: 34px; width: auto; opacity: .8; }
.site-foot .legal { flex-basis: 100%; font-size: 13px; }

/* tool pages */
.tool-head { padding: 40px 0 12px; }
.tool-head p { color: var(--ink-2); max-width: 760px; }
.tool { display: grid; grid-template-columns: 340px 1fr; gap: 28px; align-items: start; padding-bottom: 56px; }
@media (max-width: 900px) { .tool { grid-template-columns: 1fr; } }
.panel { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; }
.field { margin-bottom: 16px; }
.field label { display: block; font-size: 16px; color: var(--ink-2); margin-bottom: 6px; }
.field input[type=text] { width: 100%; font: inherit; font-size: 20px; padding: 8px 12px; background: var(--bg); color: var(--ink); border: 1px solid var(--line); border-radius: 8px; }
.field input[type=text]:focus { outline: 2px solid var(--accent-2); outline-offset: 1px; }
.field input.bad { border-color: #e5484d; }
.field .hint { font-size: 14px; color: var(--ink-3); margin-top: 4px; }
.presets { display: flex; flex-wrap: wrap; gap: 8px; }
.presets .btn { padding: 6px 12px; font-size: 15px; }
.presets .btn[aria-pressed=true] { border-color: var(--accent); color: var(--accent); }
input[type=range] { width: 100%; accent-color: var(--accent); }
.stage { background: var(--bg-2); border: 1px solid var(--line); border-radius: var(--radius); }
.stage canvas { width: 100%; display: block; }
.results { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 18px; }
@media (max-width: 640px) { .results { grid-template-columns: 1fr; } }
.result { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; }
.result .label { font-size: 15px; color: var(--ink-3); }
.result .value { font-size: 30px; font-family: "LMR17", serif; margin: 2px 0 8px; overflow-wrap: anywhere; }
.result .formula { color: var(--ink-2); font-size: 17px; overflow-x: auto; overflow-y: hidden; }
.result .formula + .formula { margin-top: 6px; }
.note { margin-top: 16px; padding: 14px 18px; border-left: 3px solid var(--accent); background: var(--panel); border-radius: 0 var(--radius) var(--radius) 0; color: var(--ink-2); font-size: 16px; }
table.cmp { width: 100%; border-collapse: collapse; font-size: 16px; margin-top: 8px; }
table.cmp th, table.cmp td { text-align: left; padding: 8px 6px; border-bottom: 1px solid var(--line); vertical-align: top; }
table.cmp th { color: var(--ink-3); font-weight: 400; }
table.cmp td.num { font-variant-numeric: tabular-nums; }
table.cmp td.num:nth-child(2) { white-space: nowrap; }
.tablewrap { overflow-x: auto; }
.readout { display: grid; grid-template-columns: auto 1fr; gap: 4px 14px; font-size: 16px; margin-top: 14px; }
.readout dt { color: var(--ink-3); }
.readout dd { margin: 0; text-align: right; font-variant-numeric: tabular-nums; }
.key { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 15px; color: var(--ink-2); padding: 10px 14px; border-top: 1px solid var(--line); }
.key .sw { display: inline-block; width: 18px; height: 3px; vertical-align: middle; margin-right: 6px; border-radius: 2px; }
.prose-block { max-width: 760px; padding-bottom: 56px; color: var(--ink-2); }
.prose-block h3 { color: var(--ink); margin-top: 1.2em; }
.katex { font-size: 1.05em; }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }
.tool > *, .results > *, .two > *, .hero .wrap > * { min-width: 0; }