/* OI DS story site — shared chrome. Same tokens as index.html. */
:root{
  --teal-50:#e4fbf8;--teal-100:#d0fbf5;--teal-200:#c2f5ee;--teal-300:#84ebdd;--teal-400:#61d7c7;
  --teal-500:#3fc3b1;--teal-600:#1daf9c;--teal-700:#178c7d;--teal-900:#166264;
  --n-0:#FFFFFF;--n-25:#F8FAFC;--n-50:#F5F7FA;--n-100:#F2F5F8;--n-200:#E1E4EA;--n-400:#99A0AE;
  --n-600:#525866;--n-700:#2B303B;--n-800:#222530;--n-900:#181B25;--n-950:#0E101B;
  --red:#fb3748;--orange:#ff9147;--green:#1fc16b;--sky:#47c2ff;--purple:#7d52f4;--pink:#fb4ba3;
  --bg:var(--n-950);--bg-card:var(--n-900);--bg-elev:var(--n-800);
  --fg:var(--n-25);--fg-2:var(--n-400);--fg-3:var(--n-600);
  --border:#232734;--brand:var(--teal-600);
  --ui:'Inter',sans-serif;--mono:'IBM Plex Mono',monospace;
  --spring:280ms cubic-bezier(0.34,1.56,0.64,1);--snap:140ms cubic-bezier(0.4,0,0.2,1);
  --glow-subtle:0 0 0 3px rgba(29,175,156,.18);--glow-strong:0 0 32px rgba(29,175,156,.25);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{background:var(--bg);color:var(--fg);font-family:var(--ui);line-height:1.6;overflow-x:hidden}
::selection{background:var(--teal-600);color:var(--n-950)}
/* top nav */
#oinav{position:fixed;top:0;left:0;right:0;z-index:99;display:flex;align-items:center;gap:6px;
  padding:14px 4vw;background:rgba(14,16,27,.82);backdrop-filter:blur(14px);border-bottom:1px solid var(--border)}
#oinav .brand{font-family:var(--mono);font-size:13px;color:var(--teal-400);font-weight:600;margin-right:auto;text-decoration:none;letter-spacing:.06em}
#oinav .brand b{color:var(--fg)}
#oinav a.nl{font-size:13px;color:var(--fg-2);text-decoration:none;padding:7px 13px;border-radius:8px;transition:all var(--snap);white-space:nowrap}
#oinav a.nl:hover{color:var(--fg);background:var(--bg-elev)}
#oinav a.nl.active{color:var(--teal-300);background:rgba(29,175,156,.1)}
@media(max-width:900px){#oinav{overflow-x:auto}#oinav .brand{margin-right:10px}}
main{padding-top:64px}
/* shared type + blocks */
.wrap{max-width:1180px;margin:0 auto;padding:9vh 5vw}
.kicker{font-family:var(--mono);font-size:12px;letter-spacing:.22em;text-transform:uppercase;color:var(--teal-400);margin-bottom:18px;display:flex;align-items:center;gap:12px}
.kicker::before{content:'';width:34px;height:1px;background:var(--teal-600)}
h1{font-size:clamp(38px,5.5vw,76px);font-weight:800;line-height:1.04;letter-spacing:-.03em}
h2{font-size:clamp(26px,3.4vw,44px);font-weight:700;letter-spacing:-.02em;margin-bottom:18px}
h3{font-size:19px;font-weight:600}
.lede{font-size:clamp(15px,1.4vw,19px);color:var(--fg-2);max-width:680px}
.lede strong{color:var(--fg)}
.mono{font-family:var(--mono)}.teal{color:var(--teal-400)}
.card{background:var(--bg-card);border:1px solid var(--border);border-radius:12px;padding:24px;transition:transform var(--spring),box-shadow var(--spring),border-color var(--spring)}
.card:hover{transform:translateY(-3px);border-color:var(--teal-700);box-shadow:var(--glow-strong)}
.reveal{opacity:0;transform:translateY(30px);transition:opacity .8s cubic-bezier(.16,1,.3,1),transform .8s cubic-bezier(.16,1,.3,1)}
.reveal.in{opacity:1;transform:none}
.reveal.d1{transition-delay:.08s}.reveal.d2{transition-delay:.16s}.reveal.d3{transition-delay:.24s}.reveal.d4{transition-delay:.32s}
/* tabs */
.tabs{display:flex;gap:8px;flex-wrap:wrap;margin:34px 0 26px}
.tabs button{font-family:var(--mono);font-size:12.5px;letter-spacing:.04em;color:var(--fg-2);background:var(--bg-card);
  border:1px solid var(--border);border-radius:99px;padding:10px 20px;cursor:pointer;transition:all var(--snap)}
.tabs button:hover{color:var(--fg);border-color:var(--n-600)}
.tabs button.active{color:var(--n-950);background:var(--teal-500);border-color:var(--teal-500);font-weight:600}
.tabpanel{display:none}.tabpanel.active{display:block;animation:fadein .5s ease}
@keyframes fadein{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}
/* accordion */
.acc{border:1px solid var(--border);border-radius:12px;background:var(--bg-card);margin-bottom:14px;overflow:hidden}
.acc>button{width:100%;display:flex;align-items:center;gap:14px;padding:20px 24px;background:none;border:none;color:var(--fg);
  font-family:var(--ui);font-size:17px;font-weight:600;cursor:pointer;text-align:left}
.acc>button .cnt{font-family:var(--mono);font-size:11px;color:var(--teal-400);background:rgba(29,175,156,.08);border:1px solid rgba(29,175,156,.25);padding:2px 10px;border-radius:99px}
.acc>button .chev{margin-left:auto;color:var(--fg-3);transition:transform var(--spring)}
.acc.open>button .chev{transform:rotate(180deg);color:var(--teal-400)}
.acc .body{max-height:0;overflow:hidden;transition:max-height .6s cubic-bezier(.16,1,.3,1)}
.acc.open .body{max-height:4000px}
.acc .body>div{padding:4px 24px 26px}
/* pills / chips / footer */
.chip{font-family:var(--mono);font-size:11px;color:var(--teal-300);background:rgba(29,175,156,.07);border:1px solid rgba(29,175,156,.22);padding:3px 10px;border-radius:99px}
footer.oift{padding:36px 5vw;border-top:1px solid var(--border);display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;font-family:var(--mono);font-size:12px;color:var(--fg-3);margin-top:8vh}
footer.oift .teal{color:var(--teal-500)}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}.reveal{opacity:1;transform:none}}

/* ── theme switcher ── */
#oitheme{margin-left:8px;font-family:var(--mono);font-size:12px;color:var(--fg-2);background:var(--bg-elev);
  border:1px solid var(--border);border-radius:8px;padding:6px 10px;cursor:pointer;outline:none;transition:all var(--snap)}
#oitheme:hover{color:var(--teal-300);border-color:var(--teal-700)}
/* ── LIGHT theme — real token values from [data-theme=light] ── */
html[data-theme="light"]{--bg:#F5F7FA;--bg-card:#FFFFFF;--bg-elev:#F2F5F8;--fg:#181B25;--fg-2:#525866;--fg-3:#99A0AE;
  --border:#E1E4EA;--glow-strong:0 0 28px rgba(29,175,156,.16);--brand:var(--teal-600)}
html[data-theme="light"] #oinav{background:rgba(245,247,250,.85)}
html[data-theme="light"] ::selection{background:var(--teal-200);color:var(--n-900)}
html[data-theme="light"] .kicker{color:var(--teal-700)}
html[data-theme="light"] .teal{color:var(--teal-700)}
/* ── TECHNICAL theme — engineering blueprint: grid, registration marks, sharper chrome ── */
html[data-theme="technical"]{background:var(--bg);--glow-subtle:0 0 0 2px rgba(29,175,156,.22);--glow-strong:0 0 0 1px rgba(29,175,156,.35),0 12px 40px rgba(0,0,0,.4)}
html[data-theme="technical"] body{background:transparent}
html[data-theme="technical"] body::before{content:'';position:fixed;inset:0;z-index:-2;pointer-events:none;background:var(--bg);
  background-image:linear-gradient(rgba(153,160,174,.045) 1px,transparent 1px),linear-gradient(90deg,rgba(153,160,174,.045) 1px,transparent 1px),linear-gradient(rgba(153,160,174,.07) 1px,transparent 1px),linear-gradient(90deg,rgba(153,160,174,.07) 1px,transparent 1px);
  background-size:24px 24px,24px 24px,120px 120px,120px 120px}
html[data-theme="technical"] body::after{content:'';position:fixed;inset:14px;z-index:-1;pointer-events:none;border:1px solid rgba(153,160,174,.12)}
html[data-theme="technical"] .card,html[data-theme="technical"] .acc{border-radius:6px;background:rgba(24,27,37,.88)}
html[data-theme="technical"] .card{box-shadow:inset 0 0 0 1px rgba(153,160,174,.04)}
html[data-theme="technical"] h1,html[data-theme="technical"] h2{letter-spacing:-.015em}