/* KKTeX Portfolio — the page's only stylesheet, hand-maintained.
 *
 * The look follows claude.com / anthropic.com: an ivory ground, near-black ink,
 * clay as the one accent, flat tinted panels with generous radii, and three
 * type roles — a grotesque for headings and UI, a text serif for English
 * reading copy, a mono for labels. Anthropic's own faces are not licensed for
 * use, so each role takes the closest Google Fonts face (compared side by side
 * against anthropic.com on 2026-09-27):
 *
 *   Anthropic Sans  → Hanken Grotesk
 *   Anthropic Serif → Source Serif 4
 *   Anthropic Mono  → Geist Mono (DM Mono was closer in caps, but its
 *                     hooked lowercase f reads as a glitch in code)
 *
 * Japanese is set in Noto Sans JP throughout, as claude.com/ja does. Latin runs
 * inside Japanese text keep Hanken Grotesk.
 *
 * Colour values are Claude's published palette tokens (claude.com :root). */

:root{
  --ivory:#FAF9F5;
  --paper:#F0EEE6;
  --oat:#E3DACC;
  --line:#DEDCD1;
  --line-strong:#C2C0B6;

  --ink:#141413;
  --ink-2:#3D3D3A;
  --muted:#73726C;      /* 4.6:1 on ivory */
  --faint:#87867F;      /* large text only */

  --night:#141413;
  --night-line:#3D3D3A;
  --on-night:#FAF9F5;
  --on-night-2:#C2C0B6;
  --on-night-muted:#9C9A92;

  --clay:#D97757;
  --clay-ink:#A94F2E;   /* clay dark enough for small text on ivory (5.2:1) */
  --clay-soft:#F0A083;  /* clay for small text on night */

  --sans:'Hanken Grotesk','Noto Sans JP',system-ui,sans-serif;
  --serif:'Source Serif 4',Georgia,'Noto Sans JP',serif;
  --mono:'Geist Mono',ui-monospace,Menlo,'Noto Sans JP',monospace;
  --ja:'Hanken Grotesk','Noto Sans JP',system-ui,sans-serif;

  --gutter:clamp(20px,4vw,56px);
  --ease-expo:cubic-bezier(.16,1,.3,1);
  --ease-out:cubic-bezier(.19,1,.22,1);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--ivory);color:var(--ink);font:400 16px/1.5 var(--sans);
     -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit;text-decoration:none}
img{display:block;max-width:100%;height:auto}
h1,h2,h3,p{margin:0}
h1,h2,h3{font-weight:600;text-wrap:balance}
p{text-wrap:pretty}
::selection{background:var(--clay);color:var(--ivory)}
a,button{transition:color 240ms var(--ease-out),background-color 240ms var(--ease-out),
                    box-shadow 240ms var(--ease-out),transform 240ms var(--ease-out)}
:focus-visible{outline:2px solid var(--clay);outline-offset:3px;border-radius:4px}

/* ── language ───────────────────────────────────────────────────────────────
   Both languages ship in the HTML; CSS decides which one is shown, so nothing
   enters or leaves the DOM on a switch and no reveal can be stranded mid-
   animation. site.js flips html[lang]. */
html[lang="ja"] [data-l="en"],
html[lang="en"] [data-l="ja"]{display:none!important}
[data-l="ja"]{word-break:auto-phrase}

.wrap{width:min(100% - 2 * var(--gutter),1200px);margin-inline:auto}
header[id],section[id]{scroll-margin-top:72px}

/* the TeX logo's lowered E */
.tex-e{display:inline-block;transform:translateY(.22em);margin-inline:-.09em}

.eyebrow{font:400 12.5px/1.3 var(--mono);letter-spacing:.06em;text-transform:uppercase;color:var(--muted)}

/* ── buttons ──────────────────────────────────────────────────────────────── */
.btn{display:inline-flex;align-items:center;gap:.5em;padding:12px 18px;border-radius:8px;
     font:500 14px/1 var(--sans);white-space:nowrap;cursor:pointer;border:0}
.btn-sm{padding:8px 12px;font-size:13px}
.btn-dark{background:var(--ink);color:var(--ivory)}
.btn-dark:hover{background:var(--ink-2)}
.btn-line{background:transparent;color:var(--ink);box-shadow:inset 0 0 0 1px var(--line-strong)}
.btn-line:hover{background:var(--paper);box-shadow:inset 0 0 0 1px var(--ink)}
.btn-light{background:var(--ivory);color:var(--ink)}
.btn-light:hover{background:var(--oat)}
.btn-ghost{background:transparent;color:var(--on-night);box-shadow:inset 0 0 0 1px rgba(250,249,245,.28)}
.btn-ghost:hover{box-shadow:inset 0 0 0 1px var(--on-night);background:rgba(250,249,245,.06)}
.btn .ar{font-family:var(--mono);font-size:.95em;opacity:.7}

/* ── nav ──────────────────────────────────────────────────────────────────── */
#bar{position:fixed;top:0;left:0;height:2px;width:0;background:var(--clay);z-index:40}
.nav{position:sticky;top:0;z-index:30;background:rgba(250,249,245,.88);
     -webkit-backdrop-filter:saturate(1.4) blur(14px);backdrop-filter:saturate(1.4) blur(14px);
     border-bottom:1px solid var(--line)}
.nav-in{display:flex;align-items:center;justify-content:space-between;gap:20px;height:64px}
.brand{flex:none;font:600 20px/1 var(--sans);letter-spacing:-.01em}
.nav-links{display:flex;align-items:center;gap:28px}
.nav-scroll{display:flex;align-items:center;gap:26px}
.nav-scroll a{font:400 15px/1 var(--sans);color:var(--ink-2)}
.nav-scroll a:hover{color:var(--ink)}
/* Language switch: both languages always shown, the current one filled in.
   A single button labelled with the other language read as the current one. */
.lang{flex:none;display:inline-flex;align-items:center;gap:2px;padding:3px;border-radius:10px;
      background:var(--paper);box-shadow:inset 0 0 0 1px var(--line)}
.lang svg{flex:none;width:15px;height:15px;margin:0 4px 0 7px;color:var(--muted)}
.lang button{border:0;background:transparent;cursor:pointer;padding:7px 11px;border-radius:7px;
             font:500 13px/1 var(--sans);color:var(--muted)}
.lang button:hover{color:var(--ink)}
.lang button[aria-pressed="true"]{background:var(--ink);color:var(--ivory);cursor:default}
.lang .short{display:none}

/* ── hero ─────────────────────────────────────────────────────────────────── */
.hero{padding:clamp(48px,8vw,112px) 0 clamp(72px,9vw,128px)}
.hero-top{display:flex;justify-content:space-between;gap:24px}
.hero-grid{margin-top:clamp(40px,6vw,88px);display:grid;
           grid-template-columns:minmax(0,7fr) minmax(0,5fr);gap:clamp(32px,5vw,80px);align-items:end}
.display{font:600 clamp(52px,9.4vw,132px)/1 var(--sans);letter-spacing:-.04em}
.display [data-mask]{padding-bottom:.16em;margin-bottom:-.16em}
.hero-name{margin-top:22px;font:500 clamp(18px,2vw,24px)/1.3 var(--ja);letter-spacing:.1em;color:var(--ink-2)}
.hero-name span{font:400 .62em var(--mono);letter-spacing:.06em;color:var(--muted);margin-left:.6em}
.lead{font:400 clamp(20px,1.8vw,24px)/1.5 var(--serif);color:var(--ink)}
.lead[data-l="ja"]{font:400 clamp(16px,1.4vw,18.5px)/2 var(--ja);color:var(--ink)}
.hero-links{margin-top:30px;display:flex;flex-wrap:wrap;gap:8px}

.hero-row{margin-top:clamp(48px,6vw,88px);display:grid;
          grid-template-columns:minmax(0,7fr) minmax(0,5fr);gap:16px;align-items:stretch}
.code{background:var(--night);color:var(--on-night);border-radius:20px;padding:18px 24px 26px}
.code-head{display:flex;justify-content:space-between;gap:16px;padding-bottom:14px;
           border-bottom:1px solid var(--night-line);font:400 12.5px/1 var(--mono);color:var(--on-night-muted)}
.code pre{margin:18px 0 0;font:400 14px/1.9 var(--mono);white-space:pre-wrap;word-break:break-word;
          /* the source is typed in one character at a time; reserve its
             finished height so the hero does not grow under the reader */
          min-height:calc(10 * 1.9em)}
.caret{color:var(--clay)}

.side{display:grid;gap:16px;grid-template-rows:auto 1fr}
.profile{display:flex;align-items:center;gap:16px;padding:18px 20px;border-radius:20px;background:var(--paper)}
.profile img{width:64px;height:64px;flex:none;border-radius:14px;object-fit:cover}
.who{font:600 18px/1.2 var(--sans)}
.handle{margin-top:6px;font:400 13px/1 var(--mono);color:var(--muted)}
/* the stats sit in a 2x2 grid with hairlines between the cells */
.stats{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));border-radius:20px;background:var(--paper)}
.stat{display:flex;flex-direction:column;justify-content:space-between;gap:12px;padding:20px 22px}
.stat:nth-child(even){border-left:1px solid var(--line)}
.stat:nth-child(n+3){border-top:1px solid var(--line)}
.stat-n{font:600 clamp(34px,3.6vw,46px)/1 var(--sans);letter-spacing:-.035em}
.stat-n.accent{color:var(--clay)}
.stat-l{font:400 16px/1.4 var(--serif);color:var(--ink-2)}
.stat-l[data-l="ja"]{font:400 14px/1.6 var(--ja)}

/* ── sections ─────────────────────────────────────────────────────────────── */
.section{padding:clamp(72px,10vw,144px) 0}
.section + .section{border-top:1px solid var(--line)}
.sec-head{display:flex;align-items:baseline;justify-content:space-between;gap:20px}
.sec-head .num{color:var(--clay-ink)}
.rule{margin-top:16px;height:1px;background:var(--line)}
.h2{font:600 clamp(38px,5.6vw,76px)/1.02 var(--sans);letter-spacing:-.035em}
.h2[data-l="ja"]{font:700 clamp(30px,4.2vw,54px)/1.3 var(--ja);letter-spacing:-.01em}
.h2 [data-mask],.h2[data-mask]{padding-bottom:.14em;margin-bottom:-.14em}
.sec-intro{margin-top:clamp(28px,3.6vw,48px);display:grid;
           grid-template-columns:minmax(0,7fr) minmax(0,5fr);gap:clamp(24px,4vw,64px);align-items:end}
.sec-intro p{font:400 clamp(18px,1.5vw,20px)/1.6 var(--serif);color:var(--ink-2)}
.sec-intro p[data-l="ja"]{font:400 clamp(15px,1.25vw,16.5px)/2 var(--ja)}

/* about */
.about-grid{margin-top:clamp(40px,5vw,72px);display:grid;
            grid-template-columns:minmax(0,5fr) minmax(0,7fr);gap:clamp(32px,6vw,96px)}
.schools{margin-top:28px;font:400 13px/2 var(--mono);color:var(--muted)}
.prose{display:grid;gap:1.15em}
.prose p{max-width:36em;font:400 clamp(18px,1.45vw,20px)/1.65 var(--serif);color:var(--ink-2)}
.prose p[data-l="ja"]{max-width:40em;font:400 clamp(15.5px,1.2vw,17px)/2.1 var(--ja)}

/* timeline */
.tl{margin-top:clamp(32px,4vw,56px);border-bottom:1px solid var(--line)}
.tl-row{display:grid;grid-template-columns:minmax(140px,4fr) minmax(0,8fr);gap:clamp(20px,4vw,64px);
        align-items:baseline;padding:clamp(20px,2.4vw,30px) 0;border-top:1px solid var(--line)}
.tl-year{font:500 clamp(30px,4vw,52px)/1 var(--sans);letter-spacing:-.035em;color:var(--faint)}
.tl-row.is-now .tl-year{color:var(--clay)}
.tl-text{font:400 clamp(17px,1.4vw,19px)/1.6 var(--serif);color:var(--ink-2)}
.tl-text[data-l="ja"]{font:400 clamp(15px,1.2vw,16.5px)/1.95 var(--ja)}

/* packages */
.pkg-grid{margin-top:clamp(32px,4vw,56px);display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px}
.pkg{display:flex;flex-direction:column;gap:12px;padding:24px 24px 20px;border-radius:16px;background:var(--paper)}
.pkg:hover{background:var(--oat);transform:translateY(-2px)}
.pkg-top{display:flex;justify-content:space-between;align-items:baseline;gap:10px}
.pkg-name{font:500 18px/1.2 var(--mono);letter-spacing:-.01em}
.pkg-num{font:400 12px/1 var(--mono);color:var(--clay-ink)}
.pkg-en{font:400 16px/1.55 var(--serif);color:var(--ink-2)}
.pkg-ja{font:400 13.5px/1.85 var(--ja);color:var(--muted)}
.pkg-go{margin-top:auto;padding-top:8px;font:400 12px/1 var(--mono);color:var(--muted)}
.pkg:hover .pkg-go{color:var(--clay-ink)}

/* products */
.feature{margin-top:clamp(36px,4.4vw,64px);display:grid;grid-template-columns:minmax(0,7fr) minmax(0,5fr);
         border-radius:24px;overflow:hidden;background:var(--night);color:var(--on-night)}
.feature-img{display:block;overflow:hidden;background:var(--clay)}
.feature-img img{width:100%;height:100%;object-fit:cover;transition:transform 900ms var(--ease-expo)}
.feature-img:hover img{transform:scale(1.02)}
.feature-body{display:flex;flex-direction:column;gap:18px;padding:clamp(28px,3.4vw,48px)}
.badge{align-self:flex-start;display:inline-flex;align-items:center;gap:9px;padding:8px 13px 8px 11px;border-radius:999px;
       background:rgba(217,119,87,.16);color:var(--clay-soft);font:500 12.5px/1.2 var(--mono);letter-spacing:.02em}
.badge::before{content:"";width:7px;height:7px;border-radius:50%;background:var(--clay);flex:none}
.feature h3{font:600 clamp(30px,3.2vw,44px)/1.05 var(--sans);letter-spacing:-.03em}
.feature p{font:400 clamp(17px,1.35vw,19px)/1.6 var(--serif);color:var(--on-night-2)}
.feature p[data-l="ja"]{font:400 clamp(14.5px,1.15vw,16px)/2 var(--ja)}
.facts{margin:4px 0 0;padding:0;list-style:none;border-bottom:1px solid var(--night-line)}
.facts li{display:grid;grid-template-columns:5.2em minmax(0,1fr);gap:12px;padding:11px 0;border-top:1px solid var(--night-line);
          font:400 13px/1.55 var(--mono);color:var(--on-night-2)}
.facts li b{font-weight:400;color:var(--on-night-muted)}
.facts li [data-l="ja"]{font-family:var(--ja);font-size:13.5px}
.feature-links{margin-top:auto;padding-top:6px;display:flex;flex-wrap:wrap;gap:8px}

.prod-grid{margin-top:16px;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}
.prod{display:flex;flex-direction:column;gap:18px;padding-bottom:8px}
.prod-img{overflow:hidden;border-radius:16px;background:var(--paper)}
.prod-img img{width:100%;aspect-ratio:3/2;object-fit:cover;transition:transform 900ms var(--ease-expo)}
.prod:hover .prod-img img{transform:scale(1.025)}
.prod-head{display:flex;justify-content:space-between;align-items:baseline;gap:12px}
.prod-name{font:600 21px/1.2 var(--sans);letter-spacing:-.015em}
.prod-url{font:400 12.5px/1 var(--mono);color:var(--clay-ink)}
.prod p{margin-top:-6px;font:400 16.5px/1.6 var(--serif);color:var(--ink-2)}
.prod p[data-l="ja"]{font:400 14.5px/1.95 var(--ja)}

/* writing */
.writing-grid{margin-top:clamp(36px,4.4vw,64px);display:grid;grid-template-columns:minmax(0,7fr) minmax(0,5fr);
              gap:clamp(28px,4vw,64px);align-items:start}
.list a{display:flex;justify-content:space-between;align-items:baseline;gap:16px;padding:22px 0;border-top:1px solid var(--line)}
.list a:last-child{border-bottom:1px solid var(--line)}
.list .t{font:400 clamp(19px,1.7vw,23px)/1.4 var(--serif)}
.list .t[data-l="ja"]{font:400 clamp(16px,1.4vw,18.5px)/1.8 var(--ja)}
.list .ar{font:400 13px/1 var(--mono);color:var(--muted);transition:transform 240ms var(--ease-out)}
.list a:hover{color:var(--clay-ink)}
.list a:hover .ar{color:var(--clay-ink);transform:translate(2px,-2px)}
.talk{border-radius:24px;padding:clamp(28px,3vw,40px);background:var(--oat)}
.talk .eyebrow{color:var(--clay-ink)}
.talk h3{margin-top:18px;font:600 clamp(30px,3.4vw,44px)/1.05 var(--sans);letter-spacing:-.03em}
.talk h3[data-l="ja"]{font:700 clamp(26px,3vw,38px)/1.3 var(--ja);letter-spacing:0}
.talk p{margin-top:16px;max-width:26em;font:400 clamp(16px,1.3vw,18px)/1.6 var(--serif);color:var(--ink-2)}
.talk p[data-l="ja"]{font:400 clamp(14.5px,1.15vw,16px)/2 var(--ja)}

/* now + footer */
.now{padding:clamp(80px,11vw,160px) 0 36px;background:var(--night);color:var(--on-night)}
.now .eyebrow{color:var(--on-night-muted)}
.now .num{color:var(--clay-soft)}
.now .rule{background:var(--night-line)}
.now-statement{margin-top:clamp(36px,5vw,64px);max-width:21em;
               font:400 clamp(32px,4.4vw,60px)/1.15 var(--serif);letter-spacing:-.015em}
.now-statement[data-l="ja"]{max-width:22em;font:500 clamp(24px,3.2vw,42px)/1.6 var(--ja);letter-spacing:0}
.now-statement [data-mask],.now-statement[data-mask]{padding-bottom:.12em}
.now-links{margin-top:clamp(36px,4.5vw,56px);display:flex;flex-wrap:wrap;gap:10px}
.foot{margin-top:clamp(72px,10vw,140px);padding-top:20px;border-top:1px solid var(--night-line);
      display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px}
.now .foot{font:400 12px/1.6 var(--mono);letter-spacing:.06em;text-transform:uppercase;color:var(--on-night-muted)}

/* ── motion ─────────────────────────────────────────────────────────────────
   Classes and inline styles here are only ever set by site.js, and only on
   elements it has checked are laid out and off-screen, so no-JS, reduced
   motion and the inactive language all render fully visible. */
[data-mask]{display:block;overflow:clip}
[data-mask] > .m{display:block}
@keyframes mask-rise{from{transform:translateY(110%)}to{transform:none}}
@media (prefers-reduced-motion:no-preference){
  [data-mask="now"] > .m{animation:mask-rise 1200ms var(--ease-expo) both;animation-delay:var(--d,0ms)}
}
[data-mask="view"].armed > .m{transform:translateY(110%)}
[data-mask="view"].armed.is-in > .m{transform:none;transition:transform 1050ms var(--ease-expo)}
[data-rule].armed{transform:scaleX(0);transform-origin:0 50%}
[data-rule].armed.is-in{transform:scaleX(1);transition:transform 900ms var(--ease-expo)}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}
}

/* ── responsive ───────────────────────────────────────────────────────────── */
@media (max-width:1000px){
  .pkg-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width:900px){
  .hero-grid,.hero-row,.sec-intro,.about-grid,.feature,.writing-grid{grid-template-columns:minmax(0,1fr)}
  .hero-grid{align-items:start}
  .feature-img img{height:auto}
}
@media (max-width:680px){
  .nav-in{height:56px}
  .nav-links{min-width:0;gap:14px}
  /* the anchor row scrolls sideways; the language toggle stays put */
  .nav-scroll{min-width:0;overflow-x:auto;overflow-y:hidden;gap:18px;scrollbar-width:none;-webkit-overflow-scrolling:touch}
  .nav-scroll::-webkit-scrollbar{display:none}
  .nav-scroll a{flex:none;white-space:nowrap;font-size:14px}
  .lang svg,.lang .full{display:none}
  .lang .short{display:inline;font-family:var(--mono);letter-spacing:.04em}
  .lang button{padding:7px 9px}
  .tl-row{grid-template-columns:minmax(0,1fr);gap:8px}
  .pkg-grid{grid-template-columns:minmax(0,1fr)}
  .prod-grid{grid-template-columns:minmax(0,1fr)}
  .stat{padding:18px 16px}
}