/* Spirograph Maker — Scholarly Mandala
 * Independent identity: academic serif + generative art glow.
 */

:root{
  /* warmer dark base with violet undertone */
  --bg:#0a0712;
  --bg-soft:#100b1d;
  --bg-card:#15102a;
  --line:rgba(228,221,255,.08);
  --line-strong:rgba(228,221,255,.16);

  --text:#ecebf5;
  --muted:#9694b0;
  --dim:#5d5b78;
  --cream:#f0e9d2;

  --violet:#b594ff;        /* main accent */
  --violet-deep:#7e58e0;
  --violet-soft:rgba(181,148,255,.16);
  --gold:#d4af37;          /* secondary accent */
  --gold-soft:rgba(212,175,55,.14);

  /* pattern palette (still multi-color for SVGs) */
  --p-magenta:#FF6EC7;
  --p-cyan:#7EE7FF;
  --p-amber:#FFCE5C;
  --p-mint:#7FFFBF;
  --p-coral:#FF9F87;

  --serif:"Newsreader","Source Serif 4","Times New Roman",Georgia,serif;
  --sans:"Inter","Helvetica Neue",system-ui,sans-serif;
  --mono:"JetBrains Mono","SF Mono",Menlo,Consolas,monospace;
}

*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:var(--sans);font-size:16px;line-height:1.7;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
body{
  background:
    radial-gradient(900px 600px at 12% -8%, rgba(181,148,255,.14), transparent 60%),
    radial-gradient(800px 500px at 88% 14%, rgba(212,175,55,.06), transparent 60%),
    radial-gradient(1000px 700px at 50% 110%, rgba(126,231,255,.04), transparent 65%),
    var(--bg);
  min-height:100vh;overflow-x:hidden;
}

a{color:var(--violet);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px;text-decoration-color:var(--violet-soft);transition:color .15s, text-decoration-color .15s}
a:hover{text-decoration-color:currentColor}
.muted{color:var(--muted)}
.dim{color:var(--dim)}

/* ---- headings: serif scholarly display ---- */
h1,h2,h3{font-family:var(--serif);font-weight:500;letter-spacing:-.01em;margin:0;color:var(--text)}
h1{font-size:clamp(44px,7vw,80px);line-height:1.05;font-weight:500;letter-spacing:-.025em}
h1 em{font-style:italic;color:var(--violet);font-weight:500}
h2{font-size:clamp(28px,4.2vw,40px);line-height:1.18;margin:0 0 18px}
h3{font-size:18px;line-height:1.4;margin:0 0 8px;font-weight:500}

/* Japanese: relax tight metrics tuned for Newsreader so Mincho glyphs breathe */
:lang(ja) h1{line-height:1.25;letter-spacing:.01em}
:lang(ja) h2{line-height:1.4;letter-spacing:.01em}
:lang(ja) h3{line-height:1.55;letter-spacing:0}

/* ---- topbar: wordmark, no dots ---- */
.topbar{
  position:sticky;top:0;z-index:50;
  display:flex;align-items:center;gap:14px;
  padding:18px 24px;
  background:rgba(10,7,18,.78);backdrop-filter:blur(14px);
  border-bottom:1px solid var(--line);
  font-family:var(--sans);font-size:14px;
}
.brand{font-family:var(--serif);font-size:18px;font-weight:500;letter-spacing:-.01em;color:var(--text);text-decoration:none}
.brand em{color:var(--violet);font-style:italic;font-weight:500}
.topbar .spacer{flex:1}
.topbar .lang{font-family:var(--mono);font-size:12px;letter-spacing:.05em}
.topbar .lang a{margin-left:14px;color:var(--muted);text-decoration:none}
.topbar .lang a.active{color:var(--violet)}

/* ---- main / sections ---- */
main{max-width:920px;margin:0 auto;padding:64px 28px 96px}
section{padding:64px 0;border-bottom:1px solid var(--line)}
section:last-of-type{border-bottom:none}
section:first-of-type{padding-top:24px}
@media (max-width:640px){
  main{padding:40px 18px 72px}
  section{padding:48px 0}
}

/* ---- section marker: "01 — ACADEMIC CITATION" ---- */
.section-marker{
  font-family:var(--mono);font-size:12px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--gold);margin-bottom:14px;
  display:flex;align-items:center;gap:10px;
}
.section-marker::before{content:"";display:inline-block;width:24px;height:1px;background:var(--gold)}

/* ---- hero ---- */
.hero{padding-top:48px}
.hero .lede{
  font-family:var(--serif);font-weight:400;font-size:clamp(18px,2.2vw,22px);line-height:1.55;
  color:var(--muted);max-width:46ch;margin:24px 0 32px;
}
.hero .lede strong{color:var(--cream);font-weight:500}
.hero-cta{display:flex;flex-wrap:wrap;gap:14px;align-items:center;margin-bottom:48px}
.badge{height:52px;width:auto;display:inline-block;vertical-align:middle}
.note{font-family:var(--sans);font-size:13px;color:var(--dim);margin-top:-12px;margin-bottom:28px;max-width:46ch}

/* ---- pattern gallery ---- */
.gallery{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;margin-top:32px;padding:24px;background:var(--bg-soft);border:1px solid var(--line);border-radius:14px;position:relative;overflow:hidden}
.gallery::before{content:"";position:absolute;inset:0;background:radial-gradient(ellipse at 50% 50%,rgba(181,148,255,.06),transparent 70%);pointer-events:none}
@media (max-width:720px){.gallery{grid-template-columns:repeat(2,1fr);gap:14px;padding:18px}}
.gallery img{width:100%;height:auto;display:block;border-radius:10px;background:transparent;filter:drop-shadow(0 0 16px rgba(181,148,255,.15))}
@media (prefers-reduced-motion: no-preference){
  .gallery img{animation:slow-rotate 80s linear infinite;transform-origin:50% 50%}
  .gallery img:nth-child(2){animation-direction:reverse;animation-duration:100s}
  .gallery img:nth-child(3){animation-duration:120s}
  .gallery img:nth-child(4){animation-direction:reverse;animation-duration:90s}
}
@keyframes slow-rotate{from{transform:rotate(0)}to{transform:rotate(360deg)}}
@media (prefers-reduced-motion: reduce){.gallery img{animation:none}}

/* ---- stats row ---- */
.stats-row{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;padding-top:24px}
@media (max-width:560px){.stats-row{grid-template-columns:repeat(2,1fr);gap:14px}}
.stat{padding:24px 18px;text-align:center;background:var(--bg-soft);border:1px solid var(--line);border-radius:12px}
.stat .v{font-family:var(--serif);font-size:clamp(32px,5.2vw,48px);font-weight:500;color:var(--violet);line-height:1;letter-spacing:-.02em}
.stat .v .u{font-family:var(--sans);font-size:14px;color:var(--muted);margin-left:3px;font-weight:400;letter-spacing:0}
.stat .l{font-family:var(--mono);font-size:11px;color:var(--muted);margin-top:12px;text-transform:uppercase;letter-spacing:.12em}

/* ---- academic citation: bibliographic style ---- */
.cite{margin-top:24px;padding:32px 32px 32px 36px;background:var(--bg-soft);border-radius:14px;border:1px solid var(--line);position:relative;overflow:hidden}
.cite::before{content:"";position:absolute;left:0;top:0;bottom:0;width:3px;background:linear-gradient(180deg,var(--violet),var(--gold))}
.cite-title{font-family:var(--serif);font-size:clamp(18px,2.4vw,22px);line-height:1.45;color:var(--text);margin-bottom:10px;font-weight:500}
.cite-title em{font-style:italic;color:var(--violet);font-weight:500;background:transparent;padding:0}
.cite-authors{font-family:var(--serif);font-style:italic;font-size:15px;color:var(--muted);margin-bottom:22px}
.cite-meta{list-style:none;padding:0;margin:0;display:grid;gap:10px;font-family:var(--sans);font-size:14px}
.cite-meta li{color:var(--muted);line-height:1.55;padding-left:18px;position:relative}
.cite-meta li::before{content:"·";position:absolute;left:6px;color:var(--gold);font-weight:700}
.cite-meta a{color:var(--violet);font-family:var(--mono);font-size:13px;text-decoration:underline;text-decoration-color:var(--violet-soft);text-underline-offset:3px}
.cite-meta b{color:var(--cream);font-weight:600}
.cite-meta em{color:var(--violet);font-style:italic;font-weight:500}

/* ---- mathematical background ---- */
.math-formula{margin:28px 0;padding:32px 28px;background:var(--bg-soft);border:1px solid var(--line);border-radius:12px;text-align:center;overflow-x:auto;line-height:1.9}
.math-formula code{font-family:var(--serif);font-style:normal;font-size:clamp(16px,2.2vw,21px);color:var(--cream);background:transparent;white-space:nowrap;font-weight:400}
.math-formula .var{font-family:var(--serif);font-style:italic;color:var(--violet)}
.math-facts{list-style:none;padding:0;margin:24px 0 0;display:grid;gap:14px}
.math-facts li{display:grid;grid-template-columns:160px 1fr;gap:20px;padding:18px 22px;background:var(--bg-soft);border:1px solid var(--line);border-radius:10px;font-size:15px;color:var(--muted);line-height:1.65}
@media (max-width:560px){.math-facts li{grid-template-columns:1fr;gap:6px}}
.math-facts li b{font-family:var(--serif);font-weight:500;color:var(--gold);font-style:italic;font-size:16px}
.math-coda{margin-top:24px;font-family:var(--serif);font-style:italic;color:var(--muted);font-size:15px}

/* ---- prose paragraphs ---- */
section p{font-size:16.5px;line-height:1.75;color:var(--muted);max-width:62ch;margin:0 0 14px}
section p:last-child{margin-bottom:0}
section p strong{color:var(--cream);font-weight:600}

/* ---- features grid ---- */
.features{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:8px}
@media (max-width:560px){.features{grid-template-columns:1fr}}
.feature{padding:22px 22px 20px;background:var(--bg-soft);border:1px solid var(--line);border-radius:10px}
.feature h3{font-family:var(--serif);font-weight:500;font-size:17px;color:var(--violet);margin:0 0 6px}
.feature p{margin:0;color:var(--muted);font-size:14.5px;line-height:1.65}

/* ---- howto steps ---- */
.steps{display:grid;gap:16px;margin-top:8px}
.step{background:var(--bg-soft);border:1px solid var(--line);border-radius:10px;padding:22px 22px 22px 76px;position:relative}
.step::before{content:counter(step,decimal-leading-zero);counter-increment:step;position:absolute;left:24px;top:20px;font-family:var(--serif);font-style:italic;color:var(--gold);font-size:32px;font-weight:500;line-height:1}
.steps{counter-reset:step}
.step h3{font-family:var(--serif);font-weight:500;font-size:17px;margin-bottom:4px}
.step p{margin:0;color:var(--muted);font-size:14.5px}

/* ---- use cases list ---- */
.cases{list-style:none;padding:0;margin:0;display:grid;gap:12px}
.cases li{padding:16px 22px;background:var(--bg-soft);border:1px solid var(--line);border-radius:10px;color:var(--muted);font-size:15px;line-height:1.65;position:relative;padding-left:36px}
.cases li::before{content:"";position:absolute;left:16px;top:24px;width:8px;height:8px;border-radius:50%;background:var(--violet);box-shadow:0 0 6px rgba(181,148,255,.6)}
.cases li b{color:var(--cream);font-weight:600;margin-right:6px}

/* ---- chips (for_whom) ---- */
.chips{display:flex;flex-wrap:wrap;gap:10px;margin-top:8px}
.chip{font-family:var(--sans);font-size:13px;background:var(--violet-soft);color:var(--violet);border:1px solid rgba(181,148,255,.3);border-radius:999px;padding:8px 14px;letter-spacing:.005em}

/* ---- specs (replaces terminal trust panel) ---- */
.specs{display:grid;grid-template-columns:repeat(2,1fr);gap:1px;background:var(--line);border:1px solid var(--line);border-radius:12px;overflow:hidden;margin-top:8px}
@media (max-width:560px){.specs{grid-template-columns:1fr}}
.spec{padding:18px 22px;background:var(--bg-soft);display:flex;justify-content:space-between;align-items:baseline;gap:16px}
.spec dt{font-family:var(--mono);font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:.12em;flex-shrink:0}
.spec dd{margin:0;font-family:var(--serif);font-size:15px;color:var(--cream);text-align:right}
.spec dd em{font-style:italic;color:var(--violet);font-weight:500}
.spec dd a{color:var(--violet);text-decoration:none;border-bottom:1px solid var(--violet-soft);font-family:var(--mono);font-size:13px}

/* ---- CTA ---- */
.cta-row{display:flex;flex-wrap:wrap;gap:14px;margin-top:8px}
.cta{display:inline-flex;align-items:center;gap:10px;padding:16px 32px;border-radius:10px;background:linear-gradient(135deg,var(--violet) 0%,var(--violet-deep) 100%);color:#0a0712;font-family:var(--sans);font-weight:600;font-size:15px;text-decoration:none;transition:transform .15s, box-shadow .15s;box-shadow:0 6px 22px -8px rgba(181,148,255,.5),inset 0 1px 0 rgba(255,255,255,.18)}
.cta:hover{transform:translateY(-1px);box-shadow:0 10px 26px -8px rgba(181,148,255,.6);color:#0a0712}
.cta-secondary{background:transparent;color:var(--violet);border:1px solid var(--violet-soft);box-shadow:none}
.cta-secondary:hover{background:var(--violet-soft);color:var(--violet);box-shadow:none}

/* ---- FAQ ---- */
.faq details{padding:18px 22px;background:var(--bg-soft);border:1px solid var(--line);border-radius:10px;margin-bottom:10px}
.faq summary{cursor:pointer;font-family:var(--serif);font-weight:500;font-size:17px;color:var(--cream);list-style:none;padding-right:32px;position:relative;line-height:1.45}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";position:absolute;right:0;top:0;font-family:var(--serif);font-size:22px;color:var(--gold);transition:transform .2s;line-height:1}
.faq details[open] summary::after{content:"−"}
.faq p{margin:14px 0 0;color:var(--muted);font-size:15px;line-height:1.7;max-width:none}
.faq code{font-family:var(--mono);font-size:13px;color:var(--violet);background:var(--violet-soft);padding:1px 5px;border-radius:3px}

/* ---- legal pages (privacy / terms / support) ---- */
.legal h1{font-size:clamp(34px,5vw,52px);line-height:1.15;margin-bottom:14px}
:lang(ja) .legal h1{line-height:1.35;letter-spacing:.02em}
.legal .updated{color:var(--dim);font-family:var(--mono);font-size:12px;margin:0 0 32px;letter-spacing:.05em}
.legal h2{font-family:var(--serif);font-size:22px;margin-top:36px;margin-bottom:12px;font-weight:500}
.legal h3{font-family:var(--serif);font-size:17px;margin-top:22px;margin-bottom:6px;color:var(--gold);font-weight:500;font-style:italic}
.legal p, .legal ul{color:var(--muted);font-size:15.5px;line-height:1.75}
.legal ul{padding-left:22px}
.legal li{margin-bottom:8px}
.legal a{color:var(--violet)}

/* ---- footer ---- */
footer{padding:36px 28px;border-top:1px solid var(--line);font-family:var(--sans);font-size:13px;color:var(--muted);text-align:center;background:rgba(10,7,18,.4)}
footer a{color:var(--muted);margin:0 10px;text-decoration:none;border-bottom:1px solid transparent;padding-bottom:2px;transition:color .15s, border-color .15s}
footer a:hover{color:var(--violet);border-bottom-color:var(--violet-soft)}
footer .copy{margin-top:14px;font-family:var(--mono);font-size:11px;color:var(--dim);letter-spacing:.08em}