/* P-120 / ABOUT P-120 / IMPLEMENTATION PASS 1
   Public derivative surface. Presentation only; no measurement/scoring authority. */
:root{
  --about-canvas:#f2eee2;--about-paper:#faf7ee;--about-pale:#e7ece4;--about-deep:#163d3b;
  --about-ink:#263533;--about-ink2:#4b5d58;--about-line:#bcc9c3;--about-teal:#2f7d78;
  --about-teal2:#1f5c5b;--about-warm:#b39063;--about-reverse:#f7f2e8;--about-max:1560px;
  --about-reading:760px;--about-shadow:0 24px 70px rgba(28,48,45,.08);
}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--about-canvas);color:var(--about-ink);font-family:"Prata","Noto Serif",Georgia,serif;line-height:1.68;-webkit-font-smoothing:antialiased}
body[data-theme="graphite"]{--about-canvas:#232522;--about-paper:#2b2e2b;--about-pale:#303632;--about-deep:#132d2c;--about-ink:#f0ede4;--about-ink2:#bfc9c4;--about-line:#56615d;--about-teal:#70aaa5;--about-teal2:#91c2bd;--about-warm:#c5a87e;--about-reverse:#f7f2e8;--about-shadow:0 24px 70px rgba(0,0,0,.18)}
body[data-theme="museum"]{--about-canvas:#f2eee2;--about-paper:#fbf8ef;--about-pale:#dfe7df;--about-deep:#173f3c;--about-ink:#263533;--about-ink2:#4b5d58;--about-line:#afc1ba;--about-teal:#2f7d78;--about-teal2:#1f5c5b;--about-warm:#b39063}
a{color:inherit}.skip-link{position:fixed;left:16px;top:-80px;z-index:9999;padding:10px 14px;background:var(--about-deep);color:var(--about-reverse);font:600 13px/1.2 "IBM Plex Sans",Arial,sans-serif;border-radius:4px}.skip-link:focus{top:12px}
.p120-brand53-header{position:sticky;top:0;z-index:80;background:color-mix(in srgb,var(--about-canvas) 91%,transparent);backdrop-filter:blur(18px);border-bottom:1px solid color-mix(in srgb,var(--about-line) 62%,transparent)}
.p120-brand53-header__inner{width:min(var(--about-max),calc(100% - 48px));height:74px;margin:0 auto;display:grid;grid-template-columns:auto 1fr auto auto;gap:22px;align-items:center}
.p120-brand53-brand{display:inline-flex;align-items:center;gap:10px;text-decoration:none;min-width:180px}.brand-mark{position:relative;width:30px;height:30px;display:inline-block;flex:0 0 30px}.brand-orbit{position:absolute;inset:3px;border:1px solid var(--about-teal);border-radius:50%;transform:rotate(-22deg)}.brand-orbit:after{content:"";position:absolute;left:6px;right:6px;top:50%;border-top:1px solid color-mix(in srgb,var(--about-teal) 68%,transparent);transform:rotate(42deg)}.brand-node{position:absolute;width:5px;height:5px;border-radius:50%;background:var(--about-teal)}.brand-node-a{right:2px;top:7px}.brand-node-b{left:4px;bottom:3px}.brand-lockup{display:flex;flex-direction:column;gap:1px}.brand{font:600 17px/1 "IBM Plex Sans",Arial,sans-serif;letter-spacing:.02em}.brand-sub{font:500 8px/1.2 "IBM Plex Sans",Arial,sans-serif;letter-spacing:.15em;color:var(--about-ink2)}
.p120-brand53-nav{display:flex;justify-content:center;align-items:center;gap:3px;min-width:0;font:500 12px/1.2 "IBM Plex Sans",Arial,sans-serif}.p120-brand53-navitem,.p120-brand53-mega>summary{display:inline-flex;align-items:center;min-height:34px;padding:0 10px;border-radius:999px;text-decoration:none;white-space:nowrap;cursor:pointer;color:var(--about-ink2);list-style:none}.p120-brand53-navitem:hover,.p120-brand53-navitem[aria-current="page"],.p120-brand53-mega>summary:hover{background:color-mix(in srgb,var(--about-pale) 76%,transparent);color:var(--about-ink)}.p120-brand53-mega{position:relative}.p120-brand53-mega>summary::-webkit-details-marker{display:none}.p120-brand53-mega-panel{position:absolute;right:0;top:44px;width:min(580px,80vw);padding:22px;background:var(--about-paper);border:1px solid var(--about-line);box-shadow:var(--about-shadow);border-radius:18px}.p120-brand53-mega-head{display:flex;justify-content:space-between;gap:20px;padding-bottom:12px;border-bottom:1px solid var(--about-line);font:500 12px/1.3 "IBM Plex Sans",Arial,sans-serif}.p120-brand53-mega-head span{color:var(--about-ink2)}.p120-brand53-mega-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:15px}.p120-brand53-mega-label{margin-bottom:7px;font:600 9px/1.2 "IBM Plex Sans",Arial,sans-serif;letter-spacing:.14em;text-transform:uppercase;color:var(--about-teal2)}.p120-brand53-mega-card{display:block;text-decoration:none;padding:10px;border-radius:10px}.p120-brand53-mega-card:hover{background:var(--about-pale)}.p120-brand53-mega-card strong{display:block;font:500 13px/1.3 "IBM Plex Sans",Arial,sans-serif}.p120-brand53-mega-card small{display:block;margin-top:3px;color:var(--about-ink2);font:400 10px/1.35 "IBM Plex Sans",Arial,sans-serif}
.p120-brand53-tools{display:flex;align-items:center;gap:8px;font:500 10px/1 "IBM Plex Sans",Arial,sans-serif}.p120-brand53-language{display:flex;gap:2px;border:1px solid var(--about-line);border-radius:999px;padding:3px}.p120-brand53-language a{padding:5px 7px;border-radius:999px;text-decoration:none;color:var(--about-ink2)}.p120-brand53-language a[aria-current="page"]{background:var(--about-teal2);color:#fff}.p120-brand53-theme{position:relative}.p120-brand53-theme>summary{min-height:32px;padding:0 10px;border:1px solid var(--about-line);border-radius:999px;display:flex;align-items:center;gap:7px;cursor:pointer;list-style:none}.p120-brand53-theme>summary::-webkit-details-marker{display:none}.p120-brand53-theme-dot{width:7px;height:7px;border-radius:50%;background:var(--about-teal)}.p120-brand53-theme-popover{position:absolute;right:0;top:40px;min-width:150px;padding:7px;background:var(--about-paper);border:1px solid var(--about-line);border-radius:12px;box-shadow:var(--about-shadow)}.p120-brand53-theme-option{width:100%;padding:8px;border:0;background:transparent;color:var(--about-ink);display:flex;gap:8px;align-items:center;text-align:left;border-radius:8px;cursor:pointer}.p120-brand53-theme-option:hover,.p120-brand53-theme-option.active{background:var(--about-pale)}.p120-brand53-theme-swatch{width:11px;height:11px;border-radius:50%;border:1px solid var(--about-line)}.p120-brand53-theme-swatch.ivory{background:#f2eee2}.p120-brand53-theme-swatch.graphite{background:#232522}.p120-brand53-theme-swatch.museum{background:#dfe7df}
.about-menu-btn{display:none;border:1px solid var(--about-line);background:transparent;color:var(--about-ink);font:500 11px/1 "IBM Plex Sans",Arial,sans-serif;padding:9px 12px;border-radius:999px}.about-drawer{display:none}
.about-shell{width:min(var(--about-max),calc(100% - 64px));margin:0 auto}.about-reading{width:min(var(--about-reading),100%)}.eyebrow{font:600 10px/1.25 "IBM Plex Sans",Arial,sans-serif;letter-spacing:.17em;text-transform:uppercase;color:var(--about-teal2)}.section-no{font:500 10px/1 "IBM Plex Mono",monospace;letter-spacing:.12em;color:var(--about-teal2)}
h1,h2,h3{margin:0;font-family:"Noto Serif Display","Prata",Georgia,serif;font-weight:500;line-height:1.03;letter-spacing:-.025em}h1{font-size:clamp(58px,6.8vw,116px);max-width:980px}h2{font-size:clamp(40px,4.5vw,74px);max-width:980px}h3{font-size:clamp(22px,2vw,32px);line-height:1.12}.lead{font-size:clamp(20px,1.8vw,29px);line-height:1.48;color:var(--about-ink2);max-width:850px}.body-copy{font-size:clamp(17px,1.18vw,20px);line-height:1.72;color:var(--about-ink2)}
.about-hero{padding:clamp(84px,9vw,150px) 0 clamp(76px,8vw,124px);position:relative;overflow:hidden}.about-hero:after{content:"";position:absolute;right:-10vw;top:16%;width:50vw;height:50vw;border:1px solid color-mix(in srgb,var(--about-teal) 24%,transparent);border-radius:50%;pointer-events:none}.about-hero-grid{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(330px,.65fr);gap:clamp(50px,7vw,120px);align-items:end}.about-hero .eyebrow{margin-bottom:24px}.about-hero .lead{margin:38px 0 0}.hero-side{position:relative;z-index:1;padding:28px;border-top:1px solid var(--about-teal);border-bottom:1px solid var(--about-line)}.hero-side p{margin:0;color:var(--about-ink2);font-size:16px}.hero-status{display:flex;flex-wrap:wrap;gap:8px;margin-top:22px}.hero-status span{font:500 10px/1 "IBM Plex Sans",Arial,sans-serif;letter-spacing:.06em;padding:8px 10px;border:1px solid var(--about-line);border-radius:999px}.hero-definition{margin-top:40px;padding-top:22px;border-top:1px solid var(--about-line);font-size:18px;line-height:1.55}
.about-section{padding:clamp(78px,8vw,132px) 0;border-top:1px solid color-mix(in srgb,var(--about-line) 78%,transparent)}.about-section.paper{background:var(--about-paper)}.about-section.pale{background:var(--about-pale)}.about-section.deep{background:var(--about-deep);color:var(--about-reverse);border-top:0}.about-section.deep .eyebrow,.about-section.deep .section-no{color:#8cc4bf}.about-section.deep .body-copy,.about-section.deep .lead{color:color-mix(in srgb,var(--about-reverse) 72%,transparent)}.section-head{display:grid;grid-template-columns:140px minmax(0,1fr);gap:28px;margin-bottom:clamp(46px,5vw,78px)}.section-head .title-wrap .eyebrow{margin-bottom:14px}.two-col{display:grid;grid-template-columns:minmax(0,1fr) minmax(320px,.72fr);gap:clamp(44px,7vw,110px)}.two-col p:first-child{margin-top:0}.statement{font-family:"Noto Serif Display","Prata",Georgia,serif;font-size:clamp(25px,2.3vw,40px);line-height:1.27;letter-spacing:-.015em}.statement strong{font-weight:500;color:var(--about-teal2)}
.distinction-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--about-line);border:1px solid var(--about-line)}.distinction{background:var(--about-paper);padding:28px;min-height:210px}.pale .distinction{background:color-mix(in srgb,var(--about-paper) 68%,var(--about-pale))}.distinction .code{font:500 10px/1.2 "IBM Plex Mono",monospace;color:var(--about-teal2);letter-spacing:.08em}.distinction h3{margin:18px 0 10px}.distinction p{margin:0;color:var(--about-ink2);font-size:15px;line-height:1.55}.not-equal{margin-top:38px;display:flex;flex-wrap:wrap;gap:8px}.not-equal span{padding:8px 10px;border:1px solid var(--about-line);font:500 11px/1.25 "IBM Plex Sans",Arial,sans-serif;background:color-mix(in srgb,var(--about-paper) 55%,transparent)}
.layer-map{display:grid;grid-template-columns:1fr auto 1fr auto 1fr;gap:12px;align-items:stretch}.layer-node{padding:24px;background:var(--about-paper);border:1px solid var(--about-line);min-height:170px}.layer-node strong{display:block;font:600 10px/1.2 "IBM Plex Sans",Arial,sans-serif;letter-spacing:.12em;text-transform:uppercase;color:var(--about-teal2)}.layer-node p{margin:18px 0 0;color:var(--about-ink2);font-size:15px}.arrow{display:flex;align-items:center;color:var(--about-teal2);font:300 28px/1 "IBM Plex Sans",Arial,sans-serif}.layer-note{margin-top:22px;color:var(--about-ink2);font:400 13px/1.5 "IBM Plex Sans",Arial,sans-serif}
.pipeline{display:grid;grid-template-columns:repeat(5,1fr);gap:1px;background:color-mix(in srgb,var(--about-line) 78%,transparent);border:1px solid var(--about-line)}.pipeline-step{position:relative;padding:28px 22px;background:var(--about-paper);min-height:220px}.pipeline-step .step{font:500 10px/1 "IBM Plex Mono",monospace;color:var(--about-teal2)}.pipeline-step h3{margin:18px 0 12px;font-size:23px}.pipeline-step p{margin:0;color:var(--about-ink2);font-size:14px;line-height:1.55}.pipeline-step:not(:last-child):after{content:"→";position:absolute;right:-9px;top:26px;z-index:2;color:var(--about-teal2);font:500 15px/1 "IBM Plex Sans",Arial,sans-serif}
.validation-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:14px}.validation-card{padding:22px 20px;border:1px solid color-mix(in srgb,var(--about-reverse) 22%,transparent);min-height:195px}.validation-card b{display:block;font:500 10px/1.2 "IBM Plex Sans",Arial,sans-serif;letter-spacing:.1em;text-transform:uppercase;color:#8cc4bf}.validation-card p{margin:17px 0 0;color:color-mix(in srgb,var(--about-reverse) 72%,transparent);font-size:14px;line-height:1.52}.science-boundary{margin-top:38px;max-width:980px;padding:26px 0;border-top:1px solid color-mix(in srgb,var(--about-reverse) 28%,transparent);font-family:"Noto Serif Display","Prata",Georgia,serif;font-size:clamp(24px,2.1vw,36px);line-height:1.35}
.governance-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:clamp(44px,6vw,90px)}.governance-list{display:grid;gap:1px;background:var(--about-line);border:1px solid var(--about-line)}.governance-item{background:var(--about-paper);padding:24px;display:grid;grid-template-columns:50px 1fr;gap:18px}.governance-item .gno{font:500 10px/1 "IBM Plex Mono",monospace;color:var(--about-teal2)}.governance-item strong{font-family:"Noto Serif Display","Prata",Georgia,serif;font-size:21px;font-weight:500}.governance-item p{margin:7px 0 0;color:var(--about-ink2);font-size:14px}.qualified{padding:30px;border:1px solid var(--about-line);background:color-mix(in srgb,var(--about-pale) 58%,transparent)}.qualified .eyebrow{margin-bottom:20px}.qualified p{margin:0 0 18px;color:var(--about-ink2)}.qualified p:last-child{margin-bottom:0}
.computation{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(320px,.9fr);gap:clamp(48px,8vw,130px);align-items:center}.compute-orbit{aspect-ratio:1;max-width:520px;border:1px solid color-mix(in srgb,var(--about-reverse) 28%,transparent);border-radius:50%;display:grid;place-items:center;position:relative}.compute-orbit:before,.compute-orbit:after{content:"";position:absolute;border:1px solid color-mix(in srgb,#8cc4bf 35%,transparent);border-radius:50%;inset:13%}.compute-orbit:after{inset:30%}.compute-core{width:46%;text-align:center;position:relative;z-index:2}.compute-core strong{display:block;font:500 22px/1.2 "Noto Serif Display",Georgia,serif}.compute-core small{display:block;margin-top:8px;font:400 10px/1.45 "IBM Plex Sans",Arial,sans-serif;color:color-mix(in srgb,var(--about-reverse) 65%,transparent)}.compute-tag{position:absolute;padding:7px 9px;border:1px solid color-mix(in srgb,var(--about-reverse) 24%,transparent);background:var(--about-deep);font:500 9px/1.25 "IBM Plex Sans",Arial,sans-serif;letter-spacing:.06em}.ct1{top:4%;left:35%}.ct2{right:-2%;top:44%}.ct3{bottom:8%;left:35%}.ct4{left:-3%;top:44%}
.boundary-list{display:grid;grid-template-columns:repeat(2,1fr);gap:1px;background:var(--about-line);border:1px solid var(--about-line)}.boundary-item{background:var(--about-paper);padding:26px}.boundary-item strong{display:block;font:500 18px/1.35 "Noto Serif Display",Georgia,serif}.boundary-item p{margin:10px 0 0;color:var(--about-ink2);font-size:14px}.final-definition{max-width:1100px;font-family:"Noto Serif Display","Prata",Georgia,serif;font-size:clamp(31px,3.5vw,58px);line-height:1.2;letter-spacing:-.02em}.final-links{display:flex;flex-wrap:wrap;gap:10px;margin-top:42px}.final-links a{padding:11px 15px;border:1px solid color-mix(in srgb,var(--about-reverse) 32%,transparent);border-radius:999px;text-decoration:none;font:500 11px/1.2 "IBM Plex Sans",Arial,sans-serif}.final-links a:hover{background:color-mix(in srgb,var(--about-reverse) 10%,transparent)}
.about-footer{padding:34px 0 50px;background:var(--about-canvas);border-top:1px solid var(--about-line);font:400 11px/1.5 "IBM Plex Sans",Arial,sans-serif;color:var(--about-ink2)}.about-footer-inner{display:flex;justify-content:space-between;gap:28px;align-items:flex-start}.about-footer strong{color:var(--about-ink);font-weight:500}.about-footer nav{display:flex;gap:16px;flex-wrap:wrap}.about-footer a{text-decoration:none}.about-footer a:hover{text-decoration:underline}
@media(min-width:1920px){.p120-brand53-header__inner,.about-shell{width:min(1760px,calc(100% - 96px))}.about-hero-grid{grid-template-columns:1.45fr .55fr}.distinction{min-height:230px}.pipeline-step{min-height:238px}}
@media(min-width:2560px){:root{--about-max:2100px;--about-reading:850px}.p120-brand53-header__inner,.about-shell{width:min(2100px,calc(100% - 160px))}.about-section{padding-top:150px;padding-bottom:150px}.about-hero{padding-top:170px;padding-bottom:145px}.body-copy{font-size:21px}.p120-brand53-nav{gap:6px}}
@media(max-width:1180px){.p120-brand53-header__inner{grid-template-columns:auto 1fr auto}.p120-brand53-nav{display:none}.about-menu-btn{display:block}.about-hero-grid,.two-col,.governance-grid,.computation{grid-template-columns:1fr}.hero-side{max-width:760px}.distinction-grid{grid-template-columns:repeat(2,1fr)}.pipeline{grid-template-columns:repeat(3,1fr)}.validation-grid{grid-template-columns:repeat(3,1fr)}.layer-map{grid-template-columns:1fr}.layer-map .arrow{transform:rotate(90deg);justify-content:center;height:22px}}
@media(max-width:760px){.p120-brand53-header__inner{width:calc(100% - 28px);height:64px;grid-template-columns:1fr auto;gap:10px}.p120-brand53-brand{min-width:0}.brand-sub{font-size:7px}.p120-brand53-tools{display:none}.about-menu-btn{display:block}.about-drawer{position:fixed;z-index:75;left:0;right:0;top:64px;bottom:0;padding:26px 22px;background:var(--about-deep);color:var(--about-reverse);transform:translateY(-115%);opacity:0;pointer-events:none;transition:.25s ease;display:block}.about-drawer.is-open{transform:none;opacity:1;pointer-events:auto}.about-drawer nav{display:grid;gap:1px}.about-drawer a{padding:16px 2px;border-bottom:1px solid color-mix(in srgb,var(--about-reverse) 18%,transparent);text-decoration:none;font:500 17px/1.2 "Noto Serif Display",Georgia,serif}.about-drawer small{display:block;margin-top:5px;font:400 10px/1.35 "IBM Plex Sans",Arial,sans-serif;color:color-mix(in srgb,var(--about-reverse) 62%,transparent)}.about-mobile-tools{display:flex;gap:10px;margin-top:24px}.about-mobile-tools a,.about-mobile-tools button{border:1px solid color-mix(in srgb,var(--about-reverse) 28%,transparent);background:transparent;color:var(--about-reverse);padding:9px 11px;border-radius:999px;font:500 10px/1 "IBM Plex Sans",Arial,sans-serif;text-decoration:none}.about-shell{width:calc(100% - 36px)}.about-hero{padding:72px 0 76px}.about-hero:after{width:100vw;height:100vw;right:-55vw}.about-hero-grid{gap:42px}.about-hero .lead{margin-top:28px}.hero-side{padding:22px 0}.about-section{padding:72px 0}.section-head{grid-template-columns:1fr;gap:15px;margin-bottom:42px}.distinction-grid,.pipeline,.validation-grid,.boundary-list{grid-template-columns:1fr}.distinction{min-height:0}.pipeline-step{min-height:0}.pipeline-step:not(:last-child):after{content:"↓";right:22px;top:auto;bottom:-9px}.validation-card{min-height:0}.governance-item{grid-template-columns:36px 1fr}.compute-orbit{max-width:360px;margin:0 auto}.ct1{left:31%}.ct3{left:31%}.about-footer-inner{flex-direction:column}.about-footer nav{gap:10px 14px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.about-drawer{transition:none}}
.identity-strip{margin-top:64px;display:grid;grid-template-columns:1fr 1fr;gap:1px;background:var(--about-line);border:1px solid var(--about-line)}.identity-strip>div{background:var(--about-pale);padding:26px}.identity-strip strong{display:block;margin-top:12px;font:500 clamp(27px,2.2vw,38px)/1.1 "Noto Serif Display",Georgia,serif}.identity-strip p{margin:9px 0 0;color:var(--about-ink2);font-size:14px;line-height:1.55}@media(max-width:760px){.identity-strip{grid-template-columns:1fr;margin-top:42px}}