/* ==========================================================================
   Bitácora — design system for Kiko Cisneros's research notebook
   A modern lab-notebook aesthetic: warm paper, graph-paper hints, ink text,
   confident display type, dark "under-the-hood" panels for interactive demos.
   Self-contained (system font stacks, no external requests).
   ========================================================================== */
:root{
  --paper:#f7f5ef; --paper-2:#fffefb; --ink:#20222e; --ink-soft:#4a4d5e;
  --line:#e2ddd0; --line-strong:#cfc8b6;
  --accent:#3b5bdb;        /* pen blue  */
  --accent-2:#e8590c;      /* margin-note rust */
  --accent-3:#0ca678;      /* result green */
  --grid:rgba(59,91,219,.05);
  --code-bg:#191b26; --code-fg:#e7e6f0; --code-dim:#8b8ca6;
  --maxw:760px; --wide:1080px;
  --serif:"Iowan Old Style",Georgia,"Times New Roman",serif;
  --sans:system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --mono:ui-monospace,"SF Mono","JetBrains Mono",Menlo,Consolas,monospace;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0; background:var(--paper); color:var(--ink);
  font-family:var(--serif); font-size:19px; line-height:1.65;
  background-image:linear-gradient(var(--grid) 1px,transparent 1px),
                   linear-gradient(90deg,var(--grid) 1px,transparent 1px);
  background-size:26px 26px;
  -webkit-font-smoothing:antialiased;
}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 22px}
.wide{max-width:var(--wide)}

/* ---- masthead ---- */
.masthead{border-bottom:2px solid var(--ink);margin-bottom:8px}
.masthead .wrap{display:flex;align-items:baseline;justify-content:space-between;
  padding-top:20px;padding-bottom:14px;gap:16px;flex-wrap:wrap}
.brand{font-family:var(--sans);font-weight:800;letter-spacing:-.02em;
  font-size:23px;color:var(--ink);text-decoration:none;display:flex;align-items:center;gap:10px}
.brand .dot{width:12px;height:12px;border-radius:50%;background:var(--accent);
  box-shadow:0 0 0 4px rgba(59,91,219,.15)}
.brand small{font-family:var(--mono);font-weight:500;font-size:12px;color:var(--ink-soft);
  letter-spacing:.02em}
.nav{font-family:var(--mono);font-size:13px;color:var(--ink-soft);display:flex;gap:18px}
.nav a{color:var(--ink-soft);text-decoration:none;border-bottom:1px dotted var(--line-strong)}
.nav a:hover{color:var(--accent)}

/* ---- typography ---- */
h1,h2,h3{font-family:var(--sans);font-weight:800;letter-spacing:-.025em;line-height:1.12;color:var(--ink)}
h1{font-size:clamp(30px,5.2vw,46px);margin:.4em 0 .3em}
h2{font-size:clamp(23px,3.5vw,30px);margin:1.9em 0 .5em;padding-top:.3em}
h3{font-size:20px;margin:1.5em 0 .4em;font-weight:700}
p{margin:0 0 1.15em}
a{color:var(--accent);text-decoration:none;border-bottom:1px solid rgba(59,91,219,.3)}
a:hover{border-bottom-color:var(--accent)}
strong{font-weight:700}
em{font-style:italic}
hr{border:0;border-top:1px solid var(--line-strong);margin:2.4em 0}
.lede{font-size:22px;line-height:1.55;color:var(--ink-soft);margin:.2em 0 1.4em}
code{font-family:var(--mono);font-size:.82em;background:#ece7db;padding:.12em .38em;
  border-radius:4px;border:1px solid var(--line)}
pre{background:var(--code-bg);color:var(--code-fg);font-family:var(--mono);font-size:14.5px;
  line-height:1.55;padding:18px 20px;border-radius:12px;overflow-x:auto;margin:1.4em 0;
  box-shadow:0 12px 30px -18px rgba(0,0,0,.5)}
pre code{background:none;border:0;padding:0;font-size:inherit;color:inherit}
.tok-k{color:#c792ea}.tok-s{color:#c3e88d}.tok-c{color:var(--code-dim)}.tok-f{color:#82aaff}.tok-n{color:#f78c6c}

/* ---- article header ---- */
.post-head{padding:34px 0 8px}
.kicker{font-family:var(--mono);font-size:12.5px;letter-spacing:.14em;text-transform:uppercase;
  color:var(--accent);font-weight:600;margin-bottom:14px;display:flex;gap:12px;align-items:center}
.kicker .rule{height:1px;flex:1;background:var(--line-strong)}
.post-meta{font-family:var(--mono);font-size:13px;color:var(--ink-soft);display:flex;gap:16px;
  flex-wrap:wrap;margin:14px 0 4px;align-items:center}
.tag{font-family:var(--mono);font-size:11.5px;background:var(--paper-2);border:1px solid var(--line-strong);
  color:var(--ink-soft);padding:2px 9px;border-radius:999px}

/* ---- figures / diagrams ---- */
figure{margin:2em 0;text-align:center}
figure svg{max-width:100%;height:auto}
figcaption{font-family:var(--sans);font-size:14px;color:var(--ink-soft);margin-top:12px;line-height:1.45}
.fig-frame{background:var(--paper-2);border:1px solid var(--line-strong);border-radius:16px;
  padding:26px 22px;overflow-x:auto;box-shadow:0 20px 44px -30px rgba(0,0,0,.35)}

/* ---- margin note / callout ---- */
.note{border-left:3px solid var(--accent-2);background:rgba(232,89,12,.05);
  padding:14px 18px;margin:1.6em 0;border-radius:0 10px 10px 0;font-size:17px}
.note b{font-family:var(--sans)}
.keyresult{border:1px solid var(--accent-3);background:rgba(12,166,120,.06);border-radius:12px;
  padding:16px 20px;margin:1.8em 0;font-size:17px}
.keyresult .lbl{font-family:var(--mono);font-size:11px;letter-spacing:.12em;text-transform:uppercase;
  color:var(--accent-3);font-weight:700;display:block;margin-bottom:6px}

/* ---- home / post list ---- */
.hero{padding:46px 0 24px}
.hero h1{font-size:clamp(34px,6vw,58px)}
.hero .lede{max-width:640px}
.postlist{list-style:none;padding:0;margin:20px 0 60px}
.postlist li{border-top:1px solid var(--line-strong);padding:26px 0}
.postlist li:last-child{border-bottom:1px solid var(--line-strong)}
.card-k{font-family:var(--mono);font-size:12px;color:var(--accent);letter-spacing:.06em;margin-bottom:8px}
.card-t{font-family:var(--sans);font-weight:800;font-size:26px;letter-spacing:-.02em;line-height:1.15;
  margin:0 0 8px;color:var(--ink)}
.postlist a.card-t-link{text-decoration:none;border:0}
.postlist a.card-t-link:hover .card-t{color:var(--accent)}
.card-d{color:var(--ink-soft);margin:0 0 10px;font-size:18px}
.card-m{font-family:var(--mono);font-size:12.5px;color:var(--ink-soft);display:flex;gap:14px;flex-wrap:wrap}

/* ---- footer ---- */
.foot{border-top:2px solid var(--ink);margin-top:60px}
.foot .wrap{padding:26px 22px 60px;font-family:var(--mono);font-size:13px;color:var(--ink-soft);
  display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
.foot a{color:var(--ink-soft)}

/* ---- reveal on scroll ---- */
.reveal{opacity:0;transform:translateY(14px);transition:opacity .6s ease,transform .6s ease}
.reveal.in{opacity:1;transform:none}

@media (max-width:640px){ body{font-size:18px} .lede{font-size:19px} }