:root{--bg:#F3F4F1;--ink:#0F1A24;--mute:#56626D;--rule:#C9CED2;--panel:#0A1B2B;--sig:#6FDCF5;--link:#0B6A86;--pos:#12756B;--neg:#B23A26;--open:#556987;
box-sizing:border-box;padding-top:env(safe-area-inset-top,0px);padding-bottom:env(safe-area-inset-bottom,0px)}
@media (prefers-color-scheme:dark){:root{--bg:#0C1218;--ink:#E3EAEF;--mute:#93A1AD;--rule:#26323C;--panel:#07121C;--link:#6FDCF5;--pos:#4FC3B5;--neg:#E8806C;--open:#9DB0CE}}
*{box-sizing:border-box}
html{scroll-padding-top:24px;scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font:400 18px/1.62 "Source Serif 4",Georgia,serif}
h1,h2,h3,.sans{font-family:Archivo,"Helvetica Neue",Arial,sans-serif}
.mono{font:400 .8rem/1.4 "IBM Plex Mono",ui-monospace,monospace}
a{color:var(--link)}
:focus-visible{outline:3px solid var(--link);outline-offset:2px}
.wrap{max-width:1160px;margin:0 auto;padding:0 28px}
.top{display:flex;justify-content:space-between;align-items:baseline;padding:22px 0;border-bottom:1px solid var(--rule);gap:16px;flex-wrap:wrap}
.mark{font:700 1.7rem Archivo;font-stretch:75%;text-decoration:none;color:var(--ink);letter-spacing:.01em}
.mark span{font:400 .8rem "IBM Plex Mono";color:var(--mute);margin-left:12px;letter-spacing:0}
.top nav{display:flex;gap:22px;font:500 .95rem Archivo}.top nav a{color:var(--mute);text-decoration:none}.top nav a:hover{color:var(--ink)}
.hero{padding:56px 0 36px}
h1{font:700 clamp(2.7rem,7.2vw,5.6rem)/.96 Archivo;font-stretch:70%;letter-spacing:-.015em;margin:0 0 22px;max-width:13em}
.lede{font-size:1.28rem;line-height:1.5;max-width:35em;color:var(--mute);margin:0 0 26px}
.btns{display:flex;gap:12px;flex-wrap:wrap}
.btn{font:600 .95rem Archivo;padding:11px 20px;border:1.5px solid var(--ink);background:none;color:var(--ink);text-decoration:none;cursor:pointer;border-radius:2px}
.btn.f{background:var(--ink);color:var(--bg)}
/* figure 1 */
.fig{background:var(--panel);color:#DCE8F0;border-radius:2px;padding:18px 20px 16px;margin-top:40px}
.fh{display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap;align-items:center;margin-bottom:14px}
.track{display:flex;gap:3px;flex:1;min-width:260px}
.seg{flex:1;position:relative;border:0;background:#13293D;color:#9DB4C6;font:500 .82rem Archivo;padding:9px 6px 11px;cursor:pointer;text-align:left;overflow:hidden}
.seg i{position:absolute;left:0;bottom:0;height:3px;background:var(--sig);width:0}
.seg[aria-pressed=true]{color:#fff;background:#1B3A55}
.seg span{position:relative}
.pp{font:500 .82rem Archivo;background:none;color:#DCE8F0;border:1px solid #36546F;padding:8px 14px;cursor:pointer;border-radius:2px}
.panes{display:grid;grid-template-columns:1fr 1fr;gap:3px}
.pane{margin:0;background:#0E2336;padding:14px}
.pane h3{font:600 1.05rem Archivo;margin:0 0 3px;color:#fff}
.pane h3 small{font:400 .75rem "IBM Plex Mono";color:#8FA6BA;margin-left:10px}
.st{font-size:.95rem;line-height:1.4;color:#A9BDCD;min-height:2.8em;margin:0 0 6px}
.pane canvas{width:100%;height:250px;display:block}
.g{display:grid;grid-template-columns:130px 1fr 96px;gap:10px;align-items:center;margin-top:9px;font:500 .8rem Archivo;color:#C3D3DF}
.g output{text-align:right;font:400 .78rem "IBM Plex Mono"}
.bar{height:12px;background:#0A1B2B;border:1px solid #2B4962;position:relative;background-image:repeating-linear-gradient(90deg,transparent 0 9.6%,#1C3A52 9.6% 10%)}
.bar i{display:block;height:100%;width:0;background:var(--sig)}.bar i.q{background:#8FE3B5}
.fx{display:flex;gap:16px;align-items:center;margin-top:12px;font:500 .85rem Archivo;color:#C3D3DF;flex-wrap:wrap}
.fx input{flex:1;min-width:150px;accent-color:var(--sig)}
.cap{margin:12px 0 0;max-width:62em;color:var(--mute);font-size:.92rem;line-height:1.5}
.cap b{font:500 .8rem "IBM Plex Mono";color:var(--ink);margin-right:8px}
/* body */
.body{display:grid;grid-template-columns:190px minmax(0,1fr);gap:48px;margin-top:40px}
.rail{position:sticky;top:24px;align-self:start;display:flex;flex-direction:column;gap:2px;font:500 .92rem Archivo;border-left:1px solid var(--rule)}
.rail a{padding:6px 14px;color:var(--mute);text-decoration:none;margin-left:-1px;border-left:3px solid transparent}
.rail a[aria-current=location]{color:var(--ink);border-left-color:var(--ink)}
section{padding:52px 0;border-top:1px solid var(--rule)}section:first-child{border-top:0;padding-top:12px}
h2{font:700 clamp(1.9rem,3.8vw,2.7rem)/1.04 Archivo;font-stretch:78%;letter-spacing:-.005em;margin:0 0 20px;max-width:18em}
p{margin:0 0 14px;max-width:37em}
.pull{font-size:1.35rem;line-height:1.42;border-left:3px solid var(--ink);padding-left:18px;max-width:30em}
.defs{display:grid;grid-template-columns:repeat(3,1fr);gap:28px;margin:6px 0 30px}
.defs h3{font:700 1.5rem Archivo;font-stretch:80%;margin:0 0 6px}.defs p{font-size:1rem;color:var(--mute);margin:0}
.eqs{border:1px solid var(--ink);padding:6px 22px 20px}
.eq{display:grid;grid-template-columns:70px 1fr;gap:12px;align-items:baseline;padding:16px 0;border-bottom:1px solid var(--rule);font-size:clamp(1.15rem,2.5vw,1.7rem)}
.eq .mono{color:var(--mute)}.eq em{font-size:.95rem;color:var(--mute);margin:0 6px}
.leg{display:grid;grid-template-columns:70px 1fr;gap:5px 12px;margin:16px 0 0;font-size:.98rem}.leg dt{font-style:italic}.leg dd{margin:0;color:var(--mute)}
.scale{width:100%;border-collapse:collapse;font-size:1rem;margin-top:8px}
.scale td,.scale th{text-align:left;padding:10px 14px 10px 0;border-top:1px solid var(--rule);vertical-align:top}
.scale th{font:600 .95rem Archivo;white-space:nowrap}
.seg2{display:flex;border:1px solid var(--ink);width:max-content;max-width:100%;flex-wrap:wrap;border-radius:2px;margin:6px 0 16px}
.seg2 button{font:500 .88rem Archivo;padding:8px 14px;border:0;background:none;color:var(--ink);cursor:pointer}
.seg2 button[aria-pressed=true]{background:var(--ink);color:var(--bg)}
.fr{border-top:1px solid var(--rule)}.fr:last-child{border-bottom:1px solid var(--rule)}
.fr>button{all:unset;box-sizing:border-box;width:100%;display:grid;grid-template-columns:44px 1fr 130px 150px;gap:14px;align-items:baseline;padding:15px 4px;cursor:pointer}
.fr>button:focus-visible{outline:3px solid var(--link);outline-offset:-3px}
.fr .t{font:600 1.05rem/1.3 Archivo}.fr .t small{display:block;font:400 .95rem/1.45 "Source Serif 4";color:var(--mute);margin-top:3px}
.o{font:600 .88rem Archivo}.o b{display:inline-block;width:1.1em;font-size:1.05em}
.pos .o{color:var(--pos)}.neg .o{color:var(--neg)}.mix .o{color:var(--open)}
.fd{display:none;padding:2px 4px 22px 58px;grid-template-columns:1fr 1fr;gap:6px 30px;font-size:1rem}
.fr.on .fd{display:grid}
.fd h4{margin:6px 0 2px;font:500 .78rem "IBM Plex Mono";color:var(--mute)}.fd p{margin:0}.fd .dl{grid-column:1/-1;margin-top:8px}
.fd .dl a{font:600 .88rem Archivo;border:1.5px solid var(--ink);color:var(--ink);padding:7px 13px;text-decoration:none;border-radius:2px;display:inline-block}
.two{display:grid;grid-template-columns:1fr 1fr;gap:36px}.two h3{font:700 1.3rem Archivo;font-stretch:80%;margin:0 0 10px}
.two ul{margin:0;padding-left:20px}.two li{margin-bottom:8px;font-size:1rem}
.focus{border-left:3px solid var(--sig);background:var(--panel);color:#DCE8F0;padding:26px 28px;border-radius:2px}
.focus h2{color:#fff;font-size:clamp(1.6rem,3vw,2.2rem)}.focus p{color:#B5C6D3}
.les{display:grid;grid-template-columns:1fr 1fr;gap:24px 36px;margin:0 0 36px}.les h3{font:700 1.15rem Archivo;font-stretch:80%;margin:0 0 4px}.les p{margin:0;font-size:1rem;color:var(--mute)}
footer{padding:34px 0 60px;border-top:1px solid var(--rule);color:var(--mute);font-size:.9rem;display:flex;justify-content:space-between;gap:20px;flex-wrap:wrap}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
.skip{position:fixed;top:8px;left:8px;z-index:10;transform:translateY(-150%);background:var(--ink);color:var(--bg);padding:10px 16px;font:600 .95rem Archivo}
.skip:focus{transform:translateY(0)}
.fd .why{grid-column:1/-1}
.fd .pending{font:600 .88rem Archivo;border:1.5px solid var(--rule);color:var(--mute);padding:7px 13px;border-radius:2px;display:inline-block}
.btn:disabled{cursor:default;opacity:.65}
.contact-note{margin:12px 0 0}
.schematic{color:#A9BDCD}
.fig :focus-visible{outline-color:var(--sig)}
.scale caption{text-align:left}
[hidden]{display:none!important}
@media (max-width:980px){.body{grid-template-columns:minmax(0,1fr)}.rail{display:none}}
@media (max-width:760px){.panes,.defs,.two,.fd,.les{grid-template-columns:1fr}.fr>button{grid-template-columns:36px 1fr}.fr>button .o,.fr>button .gr{grid-column:2}.fd{padding-left:4px}.g{grid-template-columns:104px 1fr 90px}.eq{grid-template-columns:1fr}}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
@media (max-width:760px){
 .wrap{padding:0 20px}
 .track{min-width:0;flex-basis:100%;display:grid;grid-template-columns:repeat(4,minmax(0,1fr))}
 .seg{min-width:0;font-size:.75rem;min-height:44px}
 .fig{padding:14px 12px}
 .pane{padding:12px}
 .g{grid-template-columns:94px minmax(24px,1fr) 76px;gap:6px}
 .g output{font-size:.7rem}
 .fx input{min-width:120px;min-height:44px;margin:0}
 .schematic{flex-basis:100%}
 .top nav{gap:16px;flex-wrap:wrap}
 .top nav a{padding:6px 0;min-height:44px;display:inline-flex;align-items:center}
 .seg2 button{min-height:44px}
 .pp{min-height:44px}
 .fr>button{row-gap:6px}
 .scale th,.scale td{overflow-wrap:anywhere}
}
@media (max-width:380px){
 .track{grid-template-columns:repeat(2,minmax(0,1fr))}
 .mark span{display:block;margin:4px 0 0}
 h1{font-size:2.7rem;overflow-wrap:break-word}
 .g{grid-template-columns:86px minmax(20px,1fr) 72px}
}