/* ============================================================
   case.css — shared case-study system for jiwoon-oh.github.io
   ------------------------------------------------------------
   One skeleton for every project page: nav → hero (title,
   subtitle, lede, byline grid, pick boxes) → sticky rail +
   numbered sections → footer.

   Colours and type follow the landing page: warm grey ground,
   charcoal text, Inter Tight for headings, Inter for body,
   1px hairlines, no shadows or blur. Charts keep their own
   colours inside the PNGs; text on the page is achromatic.

     <link rel="stylesheet" href="../../assets/case.css">

   A page should not fork these rules. Small layout tweaks for
   page-specific components go in a short <style> block.
   ============================================================ */

:root{
  --bg:#E7E5E0;
  --ink:#262626;
  --ink-2:#3D3C39;        /* secondary body text, 9.6:1 on --bg */
  --ink-3:#666460;        /* small labels and captions, 4.7:1 on --bg */
  --box:#EDEBE7;          /* panels: a shade lighter than --bg */
  --line:rgba(0,0,0,.18);
  --line-soft:rgba(0,0,0,.12);
  /* Accent names used inline in the pages (style="color:var(--rose)")
     and by .v.* / .hl-*; mapped to charcoal so emphasis reads as
     bold weight, not colour. */
  --blue:var(--ink); --violet:var(--ink); --rose:var(--ink); --mint:var(--ink); --amber:var(--ink);
  --r:2px;
  --sans:"Inter",-apple-system,system-ui,"Segoe UI",sans-serif;
  --display:"Inter Tight","Inter",-apple-system,system-ui,sans-serif;
  /* code and formulas only */
  --mono:ui-monospace,"SFMono-Regular",Consolas,"Liberation Mono",monospace;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{
  margin:0; font-family:var(--sans); color:var(--ink); background:var(--bg);
  line-height:1.75; -webkit-font-smoothing:antialiased; font-size:16px;
}
a{color:inherit;text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px}
a:hover{text-decoration-thickness:2px}
a:focus-visible{outline:2px solid var(--ink);outline-offset:3px}
.wrap{max-width:1240px;margin:0 auto;padding:0 32px}
.num,td.num,.val,.money,.stat .v{font-variant-numeric:tabular-nums}

/* ── site nav — same tone as the landing header ───────────── */
.nav{border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;
  height:72px;gap:20px}
.nav .brand{font-family:var(--display);font-weight:800;font-size:26px;
  letter-spacing:-.04em;line-height:1;text-decoration:none;white-space:nowrap}
.nav ul{display:flex;gap:24px;list-style:none;margin:0;padding:0}
.nav ul a{font-size:15px}

/* ── hero ─────────────────────────────────────────────────── */
.hero{padding:72px 32px 56px}
.kicker{font-size:12px;letter-spacing:.02em;color:var(--ink-3);margin:0 0 18px}
h1{font-family:var(--display);font-weight:800;text-transform:uppercase;
  font-size:clamp(40px,5.6vw,84px);line-height:.95;letter-spacing:-.03em;
  margin:0 0 26px;max-width:16ch}
.subtitle{font-family:var(--display);font-weight:700;font-size:clamp(20px,2vw,26px);
  line-height:1.3;letter-spacing:-.015em;margin:0 0 22px;max-width:44ch}
.subtitle em{font-style:normal}
.lede{font-size:17px;line-height:1.75;color:var(--ink-2);max-width:58ch;margin:0 0 40px}

/* byline: Distill-style info row under the title */
.byline{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.6fr) minmax(0,1fr) minmax(0,1fr);gap:0 28px;
  border-top:1px solid var(--line);border-bottom:1px solid var(--line);
  padding:16px 0 18px;margin:0}
.byline > div{min-width:0}
.byline dt{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-3);margin:0 0 6px}
.byline dd{margin:0;font-size:14px;line-height:1.55}

/* pick boxes */
.picks{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:40px 0 0}
.pick{position:relative;background:var(--box);border:1px solid var(--line-soft);
  border-radius:var(--r);padding:22px 22px 20px;
  opacity:0;transform:translateY(8px);animation:rise .5s cubic-bezier(.2,.7,.3,1) forwards}
.pick:nth-child(1){animation-delay:.05s}
.pick:nth-child(2){animation-delay:.15s}
.pick:nth-child(3){animation-delay:.25s}
@keyframes rise{to{opacity:1;transform:none}}
.pick .name{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-3);margin:0 0 10px}
.pick .val{font-family:var(--display);font-size:clamp(26px,3vw,36px);font-weight:800;
  letter-spacing:-.03em;margin:0;line-height:1.1;white-space:nowrap;color:var(--ink)}
.pick .unit{font-family:var(--sans);font-size:13px;color:var(--ink-3);font-weight:400;margin-left:5px;letter-spacing:0}
.pick .tag{display:inline-block;margin-top:14px;font-size:12px;font-weight:500;
  padding:3px 9px;border:1px solid var(--line);border-radius:var(--r);color:var(--ink)}
.pick.drop{border-style:dashed;border-color:var(--line)}
.pick.split .val{font-size:clamp(22px,2.4vw,28px)}
.picks-note{font-size:13px;line-height:1.6;color:var(--ink-3);margin:14px 0 0;max-width:110ch}

/* ── layout ───────────────────────────────────────────────── */
.main{display:grid;grid-template-columns:200px minmax(0,1fr);gap:64px;
  padding:72px 32px 32px;align-items:start}
main{min-width:0;max-width:900px}

/* rail — sticky table of contents */
.rail{position:sticky;top:28px;min-width:0;max-height:calc(100vh - 56px);overflow-y:auto}
.rail h2{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-3);margin:0 0 12px;font-weight:500}
.rail ol{list-style:none;margin:0;padding:0;border-top:1px solid var(--line)}
.rail li{margin:0;border-bottom:1px solid var(--line-soft)}
.rail a{display:block;text-decoration:none;color:var(--ink-3);padding:8px 0;font-size:13px;line-height:1.4}
.rail a:hover{color:var(--ink)}
.rail a.on{color:var(--ink);font-weight:600}
.rail .p{font-size:11.5px;color:var(--ink-3);display:block;font-weight:400}
.rail .n{font-size:11.5px;margin-right:6px}
.rail .n::before{content:"["} .rail .n::after{content:"]"}

/* sections */
section{scroll-margin-top:24px;margin:0 0 96px}
.sec-no{font-size:12px;color:var(--ink-3);letter-spacing:.02em;margin:0 0 10px}
.sec-no::before{content:"["} .sec-no::after{content:"]"}
h3{font-family:var(--display);font-size:clamp(26px,2.8vw,36px);letter-spacing:-.025em;
  font-weight:800;margin:0 0 8px;line-height:1.1}
h4{font-family:var(--display);font-weight:700;letter-spacing:-.01em}
.sec-sub{color:var(--ink-3);font-size:15px;margin:0 0 28px}
p{margin:0 0 20px;max-width:61ch;font-size:16.5px}
strong,b{font-weight:600}
.card{background:var(--box);border:1px solid var(--line-soft);border-radius:var(--r);padding:24px 26px;margin:0 0 20px}
.card.tight{padding:20px 22px}
.card h4{font-size:16.5px;margin:0 0 10px}
.card p{font-size:15.5px;margin-bottom:14px}
.card p:last-child{margin-bottom:0}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:0 0 20px}
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:0 0 20px}
.grid2>*,.grid3>*{margin:0}
.small{font-size:15.5px}
.figures{font-size:13px;color:var(--ink-3);margin:0 0 10px;font-variant-numeric:tabular-nums}
.takeaway{font-family:var(--display);font-size:20px;font-weight:600;line-height:1.5;color:var(--ink);
  max-width:54ch;margin:0 0 26px;letter-spacing:-.012em}
em{font-style:normal;font-weight:600}
.takeaway em{font-weight:700}
.hl,.hl-r,.hl-m,.hl-b,.hl-a{font-weight:600;color:var(--ink)}

/* stats */
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:12px;margin:0 0 20px}
.stat{background:var(--box);border:1px solid var(--line-soft);border-radius:var(--r);padding:16px 18px}
.stat .k{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-3);margin:0 0 6px;line-height:1.4}
.stat .v{font-family:var(--display);font-size:22px;font-weight:800;margin:0;letter-spacing:-.02em;white-space:nowrap;line-height:1.2}
.v.blue,.v.violet,.v.rose,.v.mint,.v.ink,.v.amber{color:var(--ink)}
.chip{display:inline-block;font-size:11.5px;font-weight:500;padding:1px 8px;border:1px solid var(--line);
  border-radius:var(--r);white-space:nowrap;vertical-align:middle;color:var(--ink);background:transparent;line-height:1.6}
.chip.rej,.chip.hold,.chip.na,.chip.warn,.chip.info{color:var(--ink)}

/* figure — no frame; the chart sits on the page, caption below */
figure{margin:40px 0 36px;padding:0}
figure img{width:100%;height:auto;display:block}
figcaption{font-size:13.5px;color:var(--ink-3);margin-top:14px;line-height:1.65;max-width:80ch;
  padding-top:12px;border-top:1px solid var(--line-soft)}
figcaption strong{color:var(--ink-2)}

/* table */
.table-wrap{overflow-x:auto}
table{width:100%;border-collapse:collapse;font-size:14px;min-width:420px}
th,td{padding:10px 9px;text-align:right;border-bottom:1px solid var(--line-soft);line-height:1.55}
th:first-child,td:first-child{text-align:left}
th{font-size:11px;letter-spacing:.06em;color:var(--ink-3);font-weight:500;text-transform:uppercase;
  border-bottom-color:var(--line)}
th.tl,td.tl{text-align:left}
td.lead{font-weight:600}
tr:last-child td{border-bottom:none}
tr.mark td{background:rgba(0,0,0,.035)}

/* pair rows */
.pair{display:grid;grid-template-columns:104px 1fr auto auto;gap:14px;align-items:baseline;
  padding:13px 0;border-bottom:1px solid var(--line-soft)}
.pair:last-child{border-bottom:none}
.pair .lbl{font-size:13.5px;font-weight:600}
.pair .txt{font-size:15.5px;color:var(--ink-2);line-height:1.6}
.pair .num{font-size:12.5px;color:var(--ink-3);white-space:nowrap}

/* recommendation rows */
.rec{background:var(--box);border:1px solid var(--line-soft);border-radius:var(--r);padding:0;margin:0 0 16px;overflow:hidden}
.rec > h4{margin:0;padding:18px 24px;font-size:17px;
  border-bottom:1px solid var(--line-soft);display:flex;gap:11px;align-items:baseline}
.rec > h4 .rn{font-family:var(--sans);font-weight:500;font-size:12.5px;color:var(--ink-3);flex:none}
.rrow{display:grid;grid-template-columns:124px 1fr;border-bottom:1px solid var(--line-soft)}
.rrow:last-child{border-bottom:none}
.rrow dt{font-size:11px;letter-spacing:.07em;text-transform:uppercase;
  color:var(--ink-3);padding:15px 0 15px 24px}
.rrow dd{margin:0;padding:14px 24px 14px 6px;font-size:15px;line-height:1.65;color:var(--ink-2)}
.rrow dd strong{color:var(--ink)}
dl{margin:0}

/* ── verification log ─────────────────────────────────────── */
.vlog{display:grid;gap:14px;margin:0 0 20px}
.vcard{background:var(--box);border:1px solid var(--line-soft);border-radius:var(--r);overflow:hidden}
.vcard > header{display:flex;gap:12px;align-items:baseline;flex-wrap:wrap;
  padding:16px 22px;border-bottom:1px solid var(--line-soft)}
.vcard .vid{font-size:12px;font-weight:600;color:var(--ink-3);flex:none}
.vcard .vt{font-family:var(--display);font-size:16px;font-weight:700;flex:1 1 auto;min-width:0}
.vrow{display:grid;grid-template-columns:104px 1fr;border-bottom:1px solid var(--line-soft)}
.vrow:last-child{border-bottom:none}
.vrow dt{font-size:11px;letter-spacing:.07em;text-transform:uppercase;
  color:var(--ink-3);padding:14px 0 14px 22px}
.vrow dd{margin:0;padding:13px 22px 13px 6px;font-size:14.8px;line-height:1.65;color:var(--ink-2)}
.vrow dd strong{color:var(--ink)}
/* mono block — install lines, formulas, run order */
.code{font-family:var(--mono);font-size:12.5px;color:var(--ink-2);background:var(--box);
  border:1px solid var(--line-soft);border-radius:var(--r);padding:13px 17px;margin:0 0 14px;
  overflow-x:auto;white-space:pre;line-height:1.75}
/* callout */
.callout{background:var(--box);border:1px solid var(--line-soft);border-radius:var(--r);padding:26px 28px;margin:0}
.callout .big{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-3);margin:0 0 12px}
.money{font-family:var(--display);font-size:clamp(30px,3.8vw,44px);font-weight:800;letter-spacing:-.03em;
  margin:0;line-height:1.05;color:var(--ink)}
.callout .sub{font-size:14px;color:var(--ink-3);margin:12px 0 0;line-height:1.6}

/* quote-style business question */
.bq{background:var(--box);border:1px solid var(--line-soft);border-radius:var(--r);padding:32px 34px;margin:0 0 20px}
.bq .q{font-family:var(--display);font-size:clamp(21px,2.5vw,28px);font-weight:700;letter-spacing:-.02em;line-height:1.3;margin:0;max-width:30ch}
.bq ul{margin:22px 0 0;padding:0;list-style:none}
.bq li{position:relative;padding-left:20px;font-size:15.5px;color:var(--ink-2);margin:0 0 8px}
.bq li::before{content:"–";position:absolute;left:0;top:0;color:var(--ink-3)}
.bq li:last-child{margin-bottom:0}

/* decision blocks */
h4.blk{font-size:19px;margin:44px 0 14px}
.dec{background:var(--box);border:1px solid var(--line-soft);border-radius:var(--r);padding:22px 24px;margin:0 0 12px;
  display:grid;grid-template-columns:34px 1fr;gap:16px}
.dec .idx{font-size:13px;font-weight:600;color:var(--ink-3);padding-top:2px;font-variant-numeric:tabular-nums}
.dec h4{font-size:17px;margin:0 0 7px}
.dec .why{font-size:15.5px;color:var(--ink-2);margin:0}
.dec .why b{color:var(--ink)}

/* tag lists and plain lists */
.tags{display:flex;flex-wrap:wrap;gap:7px;margin:0}
.tags span{font-size:13.5px;border:1px solid var(--line-soft);border-radius:var(--r);padding:5px 11px;color:var(--ink-2)}
ul.plain{margin:0;padding:0;list-style:none}
ul.plain li{position:relative;padding-left:30px;font-size:15.5px;color:var(--ink-2);margin:0 0 9px}
ul.plain li::before{content:"[✓]" / "";position:absolute;left:0;top:1px;font-size:11.5px;color:var(--ink-3)}
ul.plain li:last-child{margin-bottom:0}

/* repo link */
.repo{display:inline-flex;align-items:center;gap:10px;font-size:16px;font-weight:500}
.repo span{font-size:14px}

.note{font-size:14px;color:var(--ink-3);line-height:1.7;max-width:76ch}

footer{padding:36px 32px 80px;border-top:1px solid var(--line);margin-top:16px}
footer p{font-size:13px;color:var(--ink-3);margin:0 0 6px;max-width:110ch}

/* skill pills + link button */
.skills{display:flex;flex-wrap:wrap;gap:8px;margin:0}
.skill{display:inline-block;font-size:13.5px;color:var(--ink-2);background:transparent;
  border:1px solid var(--line-soft);border-radius:var(--r);padding:5px 11px;line-height:1.3;white-space:nowrap}
.card h4 + .skills{margin-top:14px}

.btn{display:inline-flex;align-items:center;gap:10px;font-size:16px;font-weight:500;margin:0 0 14px}
.btn .arw{font-size:15px}

@media (max-width:900px){
  .wrap{padding:0 20px}
  .nav .wrap{height:60px}
  .nav .brand{font-size:22px}
  .nav ul{gap:16px}
  .nav ul a{font-size:14px}
  .hero{padding:44px 20px 36px}
  .byline{grid-template-columns:1fr 1fr;gap:14px 20px}
  .main{grid-template-columns:minmax(0,1fr);gap:0;padding:44px 20px 32px}
  main{max-width:none}
  .rail{position:static;margin-bottom:44px;max-height:none;overflow:visible}
  .rail ol{display:flex;gap:18px;overflow-x:auto;padding:0 0 4px;border-top:0;border-bottom:1px solid var(--line)}
  .rail li{flex:0 0 auto;border-bottom:0}
  .rail a{white-space:nowrap}
  .rail .p{display:none}
  .grid2,.grid3{grid-template-columns:1fr}
  .stats{grid-template-columns:1fr 1fr}
  .stat .v{white-space:normal;font-size:20px}
  .picks{grid-template-columns:1fr}
  .pair{grid-template-columns:1fr;gap:5px}
  .rrow{grid-template-columns:1fr}
  .vrow{grid-template-columns:1fr}
  .vrow dt{padding:13px 22px 0}
  .vrow dd{padding:4px 22px 13px}
  .rrow dt{padding:14px 24px 0}
  .rrow dd{padding:4px 24px 14px}
  .dec{grid-template-columns:1fr;gap:8px}
  .skill{white-space:normal}
  section{margin-bottom:72px}
  footer{padding:36px 20px 80px}
}
@media (max-width:480px){
  .byline{grid-template-columns:1fr}
}
@media (prefers-reduced-motion:reduce){.pick{animation:none;opacity:1;transform:none}}