/* AutoR&D-Engineer's interactive research walkthrough; scoped to this page. */
.engineer-page{--eng-ink:var(--sf-navy);--eng-blue:var(--sf-blue);--eng-line:#dce8f2;--eng-soft:#f1f8fe}
.engineer-hero{padding:2rem 0 1.4rem;background:linear-gradient(135deg,#fff 50%,#eef7ff)}
.engineer-intro{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.15fr);gap:.75rem 2.5rem;align-items:start}
.engineer-intro h1{grid-column:1;grid-row:1}
.engineer-opening{grid-column:2;grid-row:1/span 2;align-self:center}
.engineer-hero-actions{grid-column:1;grid-row:2}
.engineer-kicker{font-size:.75rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--sf-blue-deep);line-height:1.5}
.engineer-intro h1{font-size:clamp(2rem,4.4vw,4rem);line-height:1.02;letter-spacing:-.045em;color:var(--eng-ink);font-weight:700;margin:0}
.engineer-intro h1 span{display:block;white-space:nowrap}
.engineer-question{font-size:clamp(1.2rem,1.7vw,1.5rem);line-height:1.5;letter-spacing:-.02em;color:var(--eng-ink);margin:0}
.engineer-question strong{color:var(--sf-blue-deep);font-weight:600}
.engineer-response{font-size:.9375rem;line-height:1.6;color:var(--text-secondary);margin:.8rem 0 0}
.engineer-hero-actions{display:flex;align-items:center;gap:1.25rem;flex-wrap:wrap;margin-top:0}
.engineer-hero-actions .btn{font-size:.875rem;padding:.75rem 1rem;min-height:44px;border-radius:9px}
.engineer-text-link{display:inline-flex;gap:.6rem;align-items:center;font-size:.875rem;font-weight:600;text-decoration:none;color:var(--sf-blue-deep);min-height:44px}
.engineer-text-link:hover{text-decoration:underline;text-underline-offset:4px}
.engineer-demo-link{display:flex;align-items:center;gap:.7rem;flex:none;text-decoration:none;color:var(--sf-blue-deep);font-size:.8125rem;font-weight:600}
.engineer-demo-link small{display:block;font-size:.75rem;font-weight:400;color:var(--text-muted);margin-top:.15rem}
.demo-play{display:grid;place-items:center;width:32px;height:32px;border:1px solid #bddcf3;border-radius:50%;font-size:.65rem;padding-left:2px;background:#f3faff}
.engineer-page .section-nav-title{display:none}
.engineer-page .section-nav a.sn-link{max-width:min(27rem,calc(100vw - 3rem));white-space:normal}
.engineer-page .ed{padding:3.1rem 0}
.engineer-page .section-title{font-size:2rem;line-height:1.25;margin-bottom:1.65rem;letter-spacing:-.035em}
.engineer-benchmark-card{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:2.5rem;background:linear-gradient(120deg,#fff,#f3f9ff)}
.engineer-benchmark-card p{font-size:1rem;line-height:1.85;color:var(--text-secondary)}
.engineer-benchmark-card strong{color:var(--sf-navy);font-weight:600}
.engineer-benchmark-card p a{text-underline-offset:3px}
.engineer-benchmark-card .btn{white-space:nowrap}
.engineer-benchmark-card a:focus-visible{outline:3px solid var(--sf-blue);outline-offset:4px}
@media(max-width:800px){.engineer-benchmark-card{grid-template-columns:1fr;gap:1.4rem}.engineer-benchmark-card .btn{justify-self:start;white-space:normal}}
@media(max-width:480px){.engineer-benchmark-card{padding:1.35rem}.engineer-benchmark-card p{font-size:.9375rem}.engineer-benchmark-card .btn{font-size:.875rem;padding:.75rem 1rem}}
.engineer-page .team{padding:2rem 0}
.engineer-page .team .authors{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:1.5rem;max-width:720px;margin:0 auto}
.engineer-page .team .author-img{width:88px;height:88px;border-width:3px;margin-bottom:.65rem;box-shadow:0 5px 16px rgba(3,45,96,.08)}
.engineer-page .team .author-fallback{font-size:1.6rem}
.engineer-page .team .author-name{font-size:.92rem;line-height:1.5}
.engineer-page .team .byline{margin-top:1.1rem}

/* Overview's input/output animation bridges the introduction and its case studies. */
.engineer-flow{--agent-accent:var(--sf-blue-deep);--agent-tint:#e6f3fd;--agent-drawing:#a5cae5;--agent-signal:var(--sf-blue);--flow-play-state:paused;position:relative;max-width:760px;margin:1.25rem auto 0;padding:2.1rem 1rem .85rem;border:1px solid #e0e9f1;border-radius:10px;background:rgba(255,255,255,.6)}
.engineer-flow[data-playing=true]{--flow-play-state:running}
.engineer-flow-controls{position:absolute;top:0;right:.4rem}
.engineer-flow-controls button{display:inline-flex;align-items:center;gap:.45rem;min-height:36px;padding:.35rem .5rem;border:0;border-radius:6px;background:transparent;color:var(--text-muted);font:inherit;font-size:.75rem;font-weight:500;cursor:pointer}
.engineer-flow-controls button[hidden]{display:none}
.engineer-flow-controls button:hover{background:#e5f2fd}
.engineer-flow-diagram{position:relative;display:grid;grid-template-columns:minmax(0,1fr) 120px minmax(0,1fr);align-items:start;gap:.75rem;max-width:700px;margin:0 auto}
.engineer-flow .agent-port{position:relative;z-index:1;min-width:0;text-align:center}
.engineer-flow .agent-port > span{display:block;color:var(--agent-accent);font-size:.6875rem;font-weight:600;line-height:1.5;letter-spacing:.08em;text-transform:uppercase;margin-bottom:.3rem}
.engineer-flow .agent-port strong{display:block;color:var(--sf-navy);font-size:.875rem;line-height:1.5;font-weight:600}
.engineer-flow .agent-port small{display:block;color:var(--text-secondary);font-size:.8125rem;line-height:1.5;margin-top:.2rem}
.engineer-flow .artifact-visual{display:block;width:56px;height:48px;max-width:100%;margin:0 auto .35rem;overflow:visible;fill:none;stroke-linecap:round;stroke-linejoin:round}
.engineer-flow .artifact-paper{fill:#fff;stroke:var(--agent-drawing);stroke-width:1.5}
.engineer-flow .artifact-rule{fill:none;stroke:var(--agent-drawing);stroke-width:1.5}
.engineer-flow .artifact-ink{fill:none;stroke:var(--agent-accent);stroke-width:1.8}
.engineer-flow .artifact-dot{fill:var(--agent-drawing)}
.engineer-flow .artifact-badge{fill:#fff;stroke:var(--agent-drawing);stroke-width:1.5}
.engineer-flow .artifact-check{fill:none;stroke:var(--agent-accent);stroke-width:2.5}
.engineer-flow .agent-method{position:relative;z-index:1;min-width:0;padding-top:calc(.6875rem * 1.5 + .3rem);text-align:center}
.engineer-flow .agent-core{position:relative;display:grid;place-items:center;width:40px;height:40px;margin:4px auto;border:1px solid #d1e4f2;border-radius:50%;background:#eff6fc;color:var(--agent-accent);box-shadow:0 0 0 3px #f7fbfe}
.engineer-flow .agent-core::before{content:'';position:absolute;inset:-4px;border:1px dashed var(--agent-drawing);border-radius:50%;animation:engineer-flow-orbit 22s linear infinite;animation-play-state:var(--flow-play-state)}
.engineer-flow .agent-core svg{width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:1.6;stroke-linecap:round;stroke-linejoin:round}
.engineer-flow .agent-method b{display:block;margin-top:.35rem;font-size:.8125rem;font-weight:600;line-height:1.5;color:var(--agent-accent)}
.engineer-flow .agent-flow-wires{position:absolute;top:calc(.6875rem * 1.5 + .3rem + 4px);left:17%;width:66%;height:40px;overflow:visible;fill:none;stroke-linecap:round;stroke-linejoin:round;pointer-events:none}
.engineer-flow .flow-wire{stroke:var(--agent-drawing);stroke-width:1.6}
.engineer-flow .flow-signal{stroke:var(--agent-signal);stroke-width:2.2;stroke-dasharray:12 88;animation:engineer-flow-transfer 4.8s linear infinite;animation-play-state:var(--flow-play-state)}
.engineer-flow .flow-signal-out{animation-delay:2.4s}
.engineer-flow-mobile-wire{display:none}
@keyframes engineer-flow-orbit{to{transform:rotate(360deg)}}
@keyframes engineer-flow-transfer{0%{stroke-dashoffset:100;opacity:0}10%,85%{opacity:1}100%{stroke-dashoffset:0;opacity:0}}
@media(max-width:640px){
  .engineer-flow{padding:2.1rem .75rem .85rem}
  .engineer-flow-diagram{grid-template-columns:minmax(0,1fr);gap:.5rem}
  .engineer-flow .agent-port{display:grid;grid-template-columns:40px minmax(0,1fr);gap:0 .65rem;text-align:left;align-items:center}
  .engineer-flow .agent-port > span{grid-column:2;grid-row:1;margin-bottom:.1rem}
  .engineer-flow .agent-port strong{grid-column:2;grid-row:2;font-size:.875rem}
  .engineer-flow .agent-port small{grid-column:2;grid-row:3;margin-top:.2rem}
  .engineer-flow .artifact-visual{grid-column:1;grid-row:1/span 3;width:40px;height:40px;margin:0}
  .engineer-flow .agent-method{display:flex;align-items:center;gap:.8rem;padding:0 0 0 3px;text-align:left}
  .engineer-flow .agent-core{width:34px;height:34px;flex:none;margin:0}
  .engineer-flow .agent-core svg{width:20px;height:20px}
  .engineer-flow .agent-method b{margin:0;font-size:.8125rem}
  .engineer-flow .agent-flow-wires{display:none}
  .engineer-flow-mobile-wire{display:block;width:20px;height:16px;margin-left:10px;fill:none;stroke-linecap:round;stroke-linejoin:round}
}
@media(prefers-reduced-motion:reduce){
  .engineer-flow .agent-core::before,.engineer-flow .flow-signal{animation:none}
  .engineer-flow .flow-signal{display:none}
}

/* Discovery stories: a case selector, three steps, and one mechanism at a time. */
.engineer-lab-section{padding:3rem 0;background:#f2f8fd;border-top:1px solid var(--eng-line)}
.engineer-context{margin-top:1.5rem;padding-top:1.5rem;border-top:1px solid var(--eng-line);font-size:.9375rem;line-height:1.85;scroll-margin-top:calc(var(--nav-h) + var(--subnav-h) + 24px)}
.engineer-context-columns{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.15fr);gap:2.5rem}
.engineer-context p + p{margin-top:1rem}
.engineer-context-scope{margin-top:1.5rem;font-size:.875rem;line-height:1.7}
.engineer-codebases{display:flex;align-items:center;gap:.5rem 1.75rem;flex-wrap:wrap;margin-top:.5rem}
.engineer-codebases a{display:inline-flex;align-items:center;gap:.5rem;min-height:36px;color:var(--sf-blue-deep);font-size:.875rem;font-weight:600;text-decoration:none}
.engineer-codebases a:hover{text-decoration:underline;text-underline-offset:4px}
.engineer-codebases a:focus-visible{outline:2px solid var(--sf-blue);outline-offset:4px;border-radius:2px}
.engineer-codebases a span{font-size:.8125rem}
.engineer-section-head{margin-bottom:1.6rem;max-width:790px}
.engineer-kicker{margin:0 0 .5rem}
.engineer-section-head h2{font-size:2.15rem;line-height:1.2;letter-spacing:-.04em;color:var(--eng-ink);font-weight:700}
.engineer-section-head > p:last-child{font-size:.9375rem;line-height:1.65;color:var(--text-secondary);margin:.65rem 0 0}
.discovery-lab{border:1px solid #cedfec;border-radius:20px;background:#fff;overflow:hidden;box-shadow:0 12px 36px rgba(3,45,96,.035)}
.discovery-lab [hidden]{display:none!important}
.discovery-picker{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));border-bottom:1px solid var(--eng-line);background:#f7fafc}
.discovery-picker button{position:relative;text-align:left;padding:1rem 1.4rem;border:0;border-right:1px solid var(--eng-line);color:var(--text-secondary);background:transparent;font:inherit;cursor:pointer;transition:background .2s ease,color .2s ease}
.discovery-picker button:last-child{border-right:0}
.discovery-picker b{display:block;color:var(--eng-ink);font-size:.9375rem;font-weight:600;line-height:1.5}
.discovery-picker button > span{display:block;font-size:.8125rem;line-height:1.5;margin-top:.15rem}
.discovery-picker button[aria-pressed=true]{background:#eaf5fe;color:var(--sf-blue-deep)}
.discovery-picker button[aria-pressed=true]::after{content:'';position:absolute;bottom:-1px;left:1.4rem;right:1.4rem;height:3px;background:var(--sf-blue)}
.discovery-picker button:hover{background:#eef6fc}
.discovery-steps{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:.55rem;padding:1.1rem 1.5rem;border-bottom:1px solid var(--eng-line)}
.discovery-steps button{position:relative;overflow:hidden;display:flex;align-items:center;gap:.7rem;text-align:left;border:1px solid #e0e9f0;border-radius:10px;background:#fff;padding:.8rem .9rem;font:inherit;color:var(--text-secondary);cursor:pointer;transition:border-color .2s ease,background .2s ease}
.story-step-number{display:grid;place-items:center;flex:none;width:30px;height:30px;border-radius:50%;border:1px solid #cfdfed;color:var(--text-muted);font-size:.875rem;font-weight:500;font-variant-numeric:tabular-nums}
.discovery-steps small{display:block;font-size:.75rem;line-height:1.3;color:var(--text-muted);margin-bottom:.25rem}
.discovery-steps b{display:block;font-size:.875rem;line-height:1.4;font-weight:500}
.story-step-arrow{margin-left:auto;font-size:.9375rem;color:#8da8bf}
.discovery-steps button[aria-pressed=true]{border-color:#8cbfe4;background:#f0f8ff;color:var(--sf-blue-deep)}
.discovery-steps button[aria-pressed=true] .story-step-number{border-color:var(--sf-blue);background:var(--sf-blue);color:#fff}
.discovery-steps button[data-complete=true] .story-step-number{border-color:#b7dace;background:#eef8f4;color:var(--sf-teal)}
.discovery-steps button:hover{border-color:#8cbfe4}
.discovery-lab button:focus-visible,.discovery-lab a:focus-visible{outline:3px solid var(--sf-blue);outline-offset:-3px}
.discovery-story{padding:1.8rem 2rem 0}
.story-heading{margin-bottom:1.3rem}
.story-eyebrow{display:flex;align-items:center;gap:.8rem;flex-wrap:wrap;margin-bottom:.65rem;color:var(--sf-blue-deep);font-size:.75rem;line-height:1.5}
.story-eyebrow > span:first-child{letter-spacing:.08em;text-transform:uppercase}
.story-eyebrow > span + span{border-left:1px solid #c9deed;padding-left:.8rem;color:var(--text-muted)}
.story-heading h3{font-size:1.75rem;font-weight:600;line-height:1.25;letter-spacing:-.035em;color:var(--sf-navy);margin:0 0 .6rem}
.story-heading > p{font-size:.9375rem;line-height:1.7;color:var(--text-secondary);max-width:830px;min-height:3.4em;margin:0}
.discovery-canvas{background:linear-gradient(135deg,#fbfdff,#f2f8fd);border:1px solid #d8e7f2;border-radius:14px;padding:1.25rem 2rem}
.study-visual{max-width:680px;margin:0 auto;min-height:280px;display:flex;flex-direction:column;justify-content:center}
.visual-context{font-size:.75rem;color:var(--text-muted);line-height:1.5;margin:0 0 1.15rem;letter-spacing:.02em}
.visual-caption{font-size:.8125rem;color:var(--text-secondary);line-height:1.6;text-align:center;margin:1.1rem 0 0;min-height:1.6em}
.discovery-lab .after-label{display:none}
.discovery-lab[data-step=after] .before-label{display:none}
.discovery-lab[data-step=after] .after-label{display:block}
.mechanism-before,.mechanism-after{transition:opacity .45s ease}
.mechanism-before{opacity:1;stroke:#8ca6bc}
.mechanism-after{opacity:0;stroke:var(--sf-blue)}
.discovery-lab[data-step=after] .mechanism-before{opacity:0}
.discovery-lab[data-step=after] .mechanism-after{opacity:1}
.diagram-label{display:block;color:var(--eng-ink);font-size:.8125rem;font-weight:500;line-height:1.5;margin-bottom:.65rem}
.diagram-arrow{font-size:1.25rem;color:#90b5d2;text-align:center}
.kernel-block{display:flex;align-items:center;justify-content:center;flex-direction:column;text-align:center;align-self:center;min-height:132px;border:1px solid #c4dcee;background:#fff;border-radius:10px;padding:.9rem .7rem}
.kernel-symbol{font-size:1.8rem;font-weight:500;color:var(--sf-blue);line-height:1;margin-bottom:.7rem}
.kernel-block b{font-size:.8125rem;font-weight:500;line-height:1.45;color:var(--eng-ink)}
.kernel-block small{font-size:.75rem;line-height:1.5;color:var(--text-muted);margin-top:.4rem}

/* hnswlib: compare per-query borrowing with one lease for this worker. */
.lease-queries{display:grid;grid-template-columns:repeat(3,minmax(0,1fr))}
.lease-queries > span{margin:0 .5rem;display:grid;place-items:center;min-height:46px;border:1px solid #c5dced;border-radius:7px;background:#fff;font-size:.875rem;color:var(--sf-navy)}
.lease-wires{display:block;width:100%;height:90px;fill:none;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round;overflow:visible}
.lease-wires path{vector-effect:non-scaling-stroke}
#lease-arrow path{stroke:#8ca6bc;stroke-width:1;fill:none}
.lease-wires circle{fill:var(--sf-blue);stroke:#fff;stroke-width:1.5}
.lease-resource{display:grid;place-items:center;min-height:52px;border:1px solid #c9dae7;background:#eff4f8;border-radius:8px;padding:.75rem 1rem;font-size:.875rem;line-height:1.5;color:var(--text-secondary);text-align:center;transition:background .4s ease,border-color .4s ease}
.discovery-lab[data-step=after] .lease-resource{background:#e6f3ff;border-color:#97c6e9;color:var(--sf-blue-deep)}

/* pandas: the data remains in place; the intermediate representation changes. */
.buffer-route{display:grid;grid-template-columns:minmax(0,1fr) 26px minmax(0,1fr) 26px minmax(0,1fr);gap:.8rem;align-items:center}
.buffer-source,.buffer-middle{min-width:0;text-align:center}
.data-grid,.row-label-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:3px;padding:6px;border:1px solid #bdd7eb;border-radius:8px;background:#fff;min-height:116px}
.data-grid i,.row-label-grid i{display:grid;place-items:center;font-size:.75rem;font-style:normal;line-height:1;color:#3c6484;background:#e5f2fc;min-height:30px;border-radius:3px}
.data-grid .missing-cell{background:#eef1f4;color:#8191a0}
.row-label-grid{border-style:dashed;border-color:#d0dbe4}
.row-label-grid i{background:#edf0f3;color:#8697a6}
.buffer-source > small,.buffer-middle > small{display:block;font-size:.75rem;line-height:1.5;color:var(--text-muted);margin-top:.6rem;min-height:1.5em}
.buffer-view{height:116px;border:1px solid #9ac8e9;border-radius:8px;background:repeating-linear-gradient(0deg,transparent,transparent 28px,#e0eef9 29px),#f2f9ff;padding:.8rem .5rem}
.discovery-lab[data-step=after] .buffer-view{display:flex;flex-direction:column;justify-content:center;gap:.6rem}
.buffer-view > span{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.8125rem;color:var(--sf-blue-deep);padding:.3rem 0;border:1px solid #cae2f4;border-radius:4px;background:#fff}

/* USearch: the same comparisons, with the vector norms ready to reuse. */
.norm-route{display:grid;grid-template-columns:minmax(0,.85fr) 80px minmax(0,1.5fr);align-items:center;max-width:620px;width:100%;margin:0 auto}
.query-vector{border:1px solid #c1d8e9;border-radius:12px;background:#fff;min-height:150px;padding:1rem .75rem;text-align:center;display:flex;align-items:center;justify-content:center;flex-direction:column}
.vector-symbol{display:grid;place-items:center;width:40px;height:40px;border-radius:50%;background:#eaf5fe;color:var(--sf-blue);font-family:Georgia,serif;font-size:1.6rem;font-style:italic;margin-bottom:.55rem}
.query-vector b{font-size:.875rem;font-weight:500;line-height:1.5;color:var(--eng-ink)}
.query-vector small{font-size:.75rem;line-height:1.4;color:var(--text-muted);margin-top:.55rem}
.norm-fan{width:100%;height:210px;fill:none;stroke:#a7c9e2;stroke-width:1.7;stroke-linejoin:round}
.norm-fan circle{fill:#b3d5eb;stroke:#fff}
.vector-comparisons{display:grid;gap:1rem}
.vector-comparisons > div{display:flex;align-items:center;justify-content:space-between;gap:.5rem;border:1px solid #d0e0ec;border-radius:7px;background:#fff;min-height:54px;padding:.65rem .85rem;transition:background .3s ease,border-color .3s ease}
.vector-comparisons b{font-size:.8125rem;font-weight:500;color:var(--eng-ink);line-height:1.5}
.vector-comparisons span{font-size:.75rem;color:var(--text-muted);text-align:right;line-height:1.4}
.discovery-lab[data-step=after] .vector-comparisons > div{background:#eef8ff;border-color:#a9cfea}
.discovery-lab[data-step=after] .vector-comparisons .after-label{color:var(--sf-blue-deep)}

/* String hashing: remove the adapter work around the existing kernel. */
.hash-route{display:grid;grid-template-columns:minmax(0,1fr) 26px minmax(0,1.1fr) 26px minmax(0,1fr);gap:.7rem;align-items:center}
.string-buffer{border:1px solid #c9dfef;background:#fff;border-radius:9px;padding:.8rem .7rem;text-align:center}
.string-buffer > span:not(.diagram-label){display:block;padding:.2rem .4rem;margin-top:4px;background:#edf6fc;border-radius:3px;color:#497291;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.75rem;line-height:1.3}
.string-buffer > .missing-token{color:#8b9ba8!important;background:#f0f3f6!important}
.hash-adapter{text-align:center;min-height:136px;display:grid;place-items:center;padding:.9rem .65rem;border:1px dashed #ccd9e3;border-radius:9px;background:#f0f4f7;transition:background .3s ease,border-color .3s ease}
.hash-adapter b{display:block;font-size:.875rem;font-weight:500;color:var(--eng-ink);line-height:1.5}
.hash-adapter small{display:block;font-size:.75rem;color:var(--text-muted);line-height:1.6;margin-top:.55rem}
.discovery-lab[data-step=after] .hash-adapter{background:#eaf6ff;border:1px solid #a4cce9}
.discovery-lab[data-step=after] .hash-adapter b{color:var(--sf-blue-deep)}

/* The lab explains verification; numerical results live in the study disclosures. */
.discovery-proof{padding:1.5rem;border:1px solid #d3e5f1;border-radius:14px;background:#f3f9fe}
.proof-checks{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1.5rem}
.proof-checks > div{display:flex;align-items:flex-start;gap:.8rem}
.proof-checks > div > span{display:grid;place-items:center;flex:none;width:28px;height:28px;border-radius:50%;border:1px solid #c3ddda;background:#f0faf5;color:var(--sf-teal);font-size:.875rem}
.proof-checks p{margin:0}
.proof-checks b{display:block;font-size:.9375rem;font-weight:500;line-height:1.5;color:var(--eng-ink);margin-bottom:.5rem}
.proof-checks p > span{display:block;font-size:.875rem;line-height:1.7;color:var(--text-secondary)}
.story-footer{display:flex;justify-content:flex-end;align-items:center;gap:.7rem 1rem;flex-wrap:wrap;margin-top:1.1rem;padding:.7rem 0 1.1rem}
.story-footer > div{display:flex;align-items:center;gap:1.1rem;flex-wrap:wrap}
.story-footer a{font-size:.8125rem;font-weight:500;line-height:1.5;color:var(--sf-blue-deep);text-decoration:none;padding:.4rem 0}
.story-footer a:hover{text-decoration:underline;text-underline-offset:4px}
.story-footer a span{padding-left:.3rem}
.discovery-navigation{display:flex;justify-content:space-between;align-items:center;gap:.6rem;padding:1rem 2rem;border-top:1px solid var(--eng-line);background:#f9fbfd}
.discovery-navigation button{font:inherit;font-size:.875rem;font-weight:500;line-height:1.5;padding:.65rem 1rem;border-radius:8px;min-height:42px;border:1px solid #bfd8eb;background:#fff;color:var(--sf-blue-deep);cursor:pointer}
.discovery-navigation button:last-child{background:var(--sf-blue-deep);color:#fff;border-color:var(--sf-blue-deep)}
.discovery-navigation button:disabled{opacity:.4;cursor:default}
.discovery-navigation > span{font-size:.75rem;line-height:1.5;color:var(--text-muted);font-variant-numeric:tabular-nums}
.engineer-sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
.engineer-page .opt-head[id]{scroll-margin-top:calc(var(--nav-h) + var(--subnav-h) + 24px)}

.engineer-page .disc{border-color:#d8e6f1;border-radius:18px;box-shadow:0 7px 24px rgba(3,45,96,.025);scroll-margin-top:calc(var(--nav-h) + var(--subnav-h) + 20px)}
.engineer-page .disc-head{padding-bottom:1rem;border-bottom:1px solid #e4edf5}
.engineer-page .disc-badge{background:#e8f4fe;color:var(--sf-blue-deep);box-shadow:none}
.engineer-page #demo{background:#eef6fc}
.engineer-page #next .abstract{border-left:3px solid var(--sf-blue);border-radius:0 14px 14px 0}
.engineer-page .eng-enter{animation:eng-enter .6s ease both}
@keyframes eng-enter{from{opacity:.35;transform:translateY(12px)}to{opacity:1;transform:none}}
@media(max-width:900px){
  .engineer-intro,.engineer-context-columns{column-gap:2rem}
  .engineer-hero-actions{gap:.5rem 1rem}
  .discovery-picker button{padding:.9rem 1rem}
  .discovery-steps{padding:1.1rem;gap:.5rem}
  .discovery-steps button{gap:.5rem;padding:.7rem .65rem}
  .story-step-arrow{display:none}
  .discovery-story{padding:1.5rem 1.4rem 0}
  .discovery-canvas{padding:1.25rem}
  .buffer-route,.hash-route{gap:.5rem;grid-template-columns:minmax(0,1fr) 18px minmax(0,1fr) 18px minmax(0,1fr)}
  .discovery-proof{padding:1.25rem}
}
@media(max-width:640px){
  .engineer-hero{padding:1.4rem 0 1.3rem}
  .engineer-intro{display:block}
  .engineer-intro h1{font-size:clamp(2rem,9.5vw,3.75rem)}
  .engineer-opening{margin-top:1rem}
  .engineer-question{font-size:1.25rem}
  .engineer-hero-actions{margin-top:1.2rem;gap:.5rem 1rem}
  .engineer-context{margin-top:1.5rem;padding-top:1.4rem}
  .engineer-context-columns{grid-template-columns:minmax(0,1fr);gap:1rem}
  .engineer-codebases{gap:.25rem 1.4rem}
  .engineer-page .team .authors{grid-template-columns:repeat(2,minmax(0,1fr));gap:1.5rem 1rem}
  .engineer-page .team .author-img{width:80px;height:80px}
  .engineer-lab-section{padding:2.4rem 0}
  .engineer-section-head h2{font-size:1.8rem}
  .discovery-lab{border-radius:15px}
  .discovery-picker{grid-template-columns:repeat(2,minmax(0,1fr))}
  .discovery-picker button{padding:.8rem 1rem;border-bottom:1px solid var(--eng-line)}
  .discovery-picker button:nth-child(2){border-right:0}
  .discovery-picker button:nth-last-child(-n+2){border-bottom:0}
  .discovery-picker button[aria-pressed=true]::after{left:1rem;right:1rem}
  .discovery-steps{padding:.9rem .75rem;gap:.4rem}
  .discovery-steps button{align-items:center;justify-content:flex-start;flex-direction:column;gap:.5rem;padding:.6rem .3rem;text-align:center;border-radius:8px}
  .discovery-steps small{display:none}
  .discovery-steps b{font-size:.8125rem;line-height:1.4;max-width:90px}
  .story-step-number{width:27px;height:27px;font-size:.8125rem}
  .discovery-story{padding:1.2rem 1rem 0}
  .story-heading h3{font-size:1.5rem}
  .story-heading > p{min-height:0;font-size:.9375rem}
  .story-eyebrow{gap:.35rem .6rem}
  .story-eyebrow > span + span{padding-left:0;border:0;flex-basis:100%}
  .discovery-canvas{padding:1rem .8rem}
  .study-visual{min-height:270px}
  .lease-queries > span{margin:0 .2rem;font-size:.8125rem;min-height:42px}
  .lease-resource{font-size:.8125rem;padding:.7rem .6rem}
  .visual-context{font-size:.75rem;margin-bottom:1rem}
  .visual-caption{font-size:.75rem}
  .buffer-route,.hash-route{grid-template-columns:minmax(0,1fr) 16px minmax(0,1fr);gap:.7rem .25rem}
  .buffer-route > .diagram-arrow:nth-last-child(2),.hash-route > .diagram-arrow:nth-last-child(2){grid-row:2;grid-column:2;transform:rotate(90deg)}
  .buffer-route > .kernel-block,.hash-route > .kernel-block{grid-column:1/-1;grid-row:3;min-height:65px;padding:.6rem;flex-direction:row;gap:.7rem;flex-wrap:wrap}
  .kernel-block .kernel-symbol{margin:0;font-size:1.5rem}
  .kernel-block small{margin:0}
  .diagram-label{font-size:.75rem}
  .data-grid,.row-label-grid{min-height:98px;padding:4px;gap:2px}
  .data-grid i,.row-label-grid i{min-height:27px;font-size:.75rem}
  .buffer-view{height:98px}
  .buffer-source > small,.buffer-middle > small{font-size:.75rem;min-height:3em}
  .norm-route{grid-template-columns:minmax(0,.9fr) 35px minmax(0,1.15fr)}
  .query-vector{min-height:140px;padding:.8rem .5rem}
  .query-vector b{font-size:.8125rem}
  .vector-comparisons{gap:.65rem}
  .vector-comparisons > div{flex-direction:column;align-items:flex-start;gap:.25rem;padding:.6rem;min-height:62px}
  .vector-comparisons span{text-align:left}
  .norm-fan{height:220px}
  .hash-adapter{padding:.85rem .45rem;min-height:150px}
  .hash-adapter b{font-size:.8125rem}
  .hash-adapter small br{display:none}
  .discovery-proof{padding:1.1rem}
  .proof-checks{grid-template-columns:minmax(0,1fr);gap:1.5rem}
  .story-footer{gap:.4rem;padding-bottom:.9rem}
  .story-footer > div{gap:1rem}
  .discovery-navigation{padding:.85rem 1rem;flex-wrap:wrap}
  .discovery-navigation > span{order:-1;flex-basis:100%;text-align:center;margin-bottom:.3rem}
  .discovery-navigation button{font-size:.8125rem;padding:.6rem .75rem}
  .engineer-page .ed{padding:2.5rem 0}
  .engineer-page .section-title{font-size:1.75rem}
  .engineer-page .card.disc{padding:1.3rem}
}
@media(prefers-reduced-motion:reduce){
  .engineer-page *, .engineer-page *::before,.engineer-page *::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}
}
.story-heading{scroll-margin-top:calc(var(--nav-h) + var(--subnav-h) + 20px)}
@media(prefers-reduced-motion:no-preference){
  .discovery-lab[data-step=after] .buffer-view > span{animation:study-reveal .5s ease both}
  .discovery-lab[data-step=after] .buffer-view > span:nth-child(2){animation-delay:.12s}
  .discovery-lab[data-step=after] .vector-comparisons .after-label{animation:study-reveal .5s ease both}
  .discovery-lab[data-step=after] .vector-comparisons > div:nth-child(2) .after-label{animation-delay:.1s}
  .discovery-lab[data-step=after] .vector-comparisons > div:nth-child(3) .after-label{animation-delay:.2s}
  .discovery-lab[data-step=after] .hash-adapter .after-label{animation:study-reveal .5s ease both}
  .discovery-lab[data-step=evidence] .discovery-proof{animation:study-reveal .4s ease both}
}
@keyframes study-reveal{from{opacity:.2;transform:translateY(5px)}to{opacity:1;transform:none}}

/* Results stay visible: project gains lead into one complete study at a time. */
.findings-alias{display:block;height:0;scroll-margin-top:calc(var(--nav-h) + var(--subnav-h) + 20px)}
.engineer-page #findings .section-title{text-align:left;margin-bottom:.7rem}
.findings-intro{font-size:1rem;line-height:1.75;color:var(--text-secondary);margin:0 0 1.6rem}
.findings-system{white-space:nowrap}
.findings-picker{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));border:1px solid #cedfec;border-radius:16px;overflow:hidden;margin:0 0 1.25rem;background:#fff}
.findings-picker[hidden],.optimization-picker[hidden],.finding-study[hidden],.finding-optimization[hidden]{display:none!important}
.findings-picker button{position:relative;display:flex;align-items:stretch;flex-direction:column;text-align:left;padding:1.2rem;border:0;border-right:1px solid #d7e5f0;font:inherit;background:#fff;color:var(--sf-navy);cursor:pointer;transition:background .25s ease,color .25s ease}
.findings-picker button:last-child{border-right:0}
.finding-project-name{display:flex;align-items:center;justify-content:space-between;gap:.5rem;font-size:.875rem;font-weight:600;line-height:1.5;margin-bottom:.45rem}
.finding-project-name > span{font-size:.8125rem;font-weight:400;color:#5b8cad}
.finding-count{align-self:flex-start;display:inline-flex;padding:.15rem .45rem;margin-bottom:.95rem;border:1px solid #d5e6f4;border-radius:5px;background:#eff6fd;color:var(--sf-blue-deep);font-size:.75rem;font-weight:500;line-height:1.5}
.finding-gain{display:flex;flex-direction:column;gap:.3rem;margin-top:auto}
.finding-gain small{font-size:.75rem;color:var(--text-muted);line-height:1.5}
.finding-gain strong{font-size:clamp(1.65rem,2.8vw,2.35rem);line-height:1.1;letter-spacing:-.045em;font-weight:600;color:var(--sf-blue-deep);font-variant-numeric:tabular-nums}
.finding-gain-label{display:block;font-size:.8125rem;line-height:1.5;color:var(--text-secondary);margin-top:.6rem}
.findings-picker button[aria-pressed=true]{background:var(--sf-navy);color:#fff}
.findings-picker button[aria-pressed=true] .finding-count{border-color:#37628e;background:#194675;color:#e2f2ff}
.findings-picker button[aria-pressed=true] .finding-gain strong{color:#fff}
.findings-picker button[aria-pressed=true] .finding-gain small,.findings-picker button[aria-pressed=true] .finding-gain-label,.findings-picker button[aria-pressed=true] .finding-project-name > span{color:#bcdef8}
.findings-picker button:hover:not([aria-pressed=true]){background:#edf7ff}
.findings-picker button:focus-visible,.optimization-picker button:focus-visible{outline:3px solid #1b96ff;outline-offset:-4px}
.engineer-page .card.finding-study{padding:1.6rem 1.75rem;margin:0;border:1px solid #d1e2ef;border-radius:16px;background:#fff;box-shadow:0 8px 28px rgba(3,45,96,.035)}
.engineer-page .finding-study .disc-head{margin-bottom:1rem;align-items:center}
.engineer-page .finding-study .disc-head h3{font-size:1.35rem;line-height:1.4;letter-spacing:-.02em}
.engineer-page .finding-study .disc-badge{width:36px;height:36px;font-size:.9375rem}
.finding-study > p{max-width:940px}
.finding-study-intro{max-width:940px;margin-bottom:1.2rem}
.finding-study-intro p{line-height:1.8;margin-bottom:.75rem}
.engineer-page .finding-study-lead{font-size:1.0625rem;line-height:1.7;color:var(--eng-ink)}
.engineer-page .finding-study-lead strong{color:var(--sf-blue-deep)}
.finding-study-intro p:last-child{margin-bottom:0}
.optimization-picker{padding:1rem;margin:1.2rem 0;border:1px solid #cbdfee;border-radius:13px;background:#f3f8fd}
.optimization-picker > h4{font-size:1rem;font-weight:600;line-height:1.4;color:var(--sf-navy);margin:0 0 .8rem;padding:0;border:0}
.optimization-options{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:.65rem}
.optimization-options-pair{grid-template-columns:repeat(2,minmax(0,1fr))}
.optimization-picker button{display:grid;grid-template-columns:28px minmax(0,1fr);column-gap:.65rem;row-gap:.45rem;align-content:start;text-align:left;font:inherit;padding:1rem .9rem;border:1px solid #caddeb;border-radius:9px;background:#fff;color:var(--sf-navy);cursor:pointer;transition:background .2s ease,border-color .2s ease,box-shadow .2s ease}
.optimization-number{display:grid;place-items:center;width:28px;height:28px;border-radius:7px;background:#edf5fc;color:var(--sf-blue-deep);font-size:.75rem;font-weight:600;font-variant-numeric:tabular-nums}
.optimization-copy{min-width:0}
.optimization-copy b{display:block;font-size:.9375rem;font-weight:600;line-height:1.45}
.optimization-copy small{display:block;font-size:.8125rem;line-height:1.5;color:var(--text-secondary);margin-top:.25rem}
.optimization-action{grid-column:2;font-size:.75rem;font-weight:600;line-height:1.5;color:var(--sf-blue-deep)}
.optimization-active{display:none}
.optimization-picker button[aria-pressed=true]{background:#e8f4ff;border-color:var(--sf-blue);box-shadow:inset 0 0 0 1px var(--sf-blue)}
.optimization-picker button[aria-pressed=true] .optimization-number{background:var(--sf-blue);color:#fff}
.optimization-picker button[aria-pressed=true] .optimization-idle{display:none}
.optimization-picker button[aria-pressed=true] .optimization-active{display:inline}
.optimization-picker button:hover:not([aria-pressed=true]){border-color:#85b6da;background:#fafdff}
.finding-optimization{padding:0;margin:0;scroll-margin-top:calc(var(--nav-h) + var(--subnav-h) + 20px)}
.engineer-page .finding-optimization > .opt-head{border-top:0;margin:1.2rem 0 .85rem;padding:0;line-height:1.5;font-size:1.125rem}
.engineer-page .finding-optimization .opt-head > span{font-size:.75rem;letter-spacing:.06em;padding:.15rem .5rem;border-radius:5px}
.engineer-page .finding-optimization figure.chart{margin-top:1.2rem}
@media(max-width:760px){
  .findings-picker{grid-template-columns:repeat(2,minmax(0,1fr))}
  .findings-picker button{padding:1.1rem;border-bottom:1px solid #d7e5f0}
  .findings-picker button:nth-child(2){border-right:0}
  .findings-picker button:nth-last-child(-n+2){border-bottom:0}
  .finding-project-name{margin-bottom:.65rem}
  .finding-gain strong{font-size:2rem}
  .finding-gain-label{font-size:.75rem;margin-top:.5rem}
  .optimization-options{grid-template-columns:minmax(0,1fr)}
  .optimization-picker{padding:.85rem}
  .optimization-picker button{padding:.8rem;row-gap:.25rem}
}
@media(max-width:640px){
  .engineer-page .card.finding-study{padding:1.2rem 1rem;border-radius:13px}
  .engineer-page .finding-study .disc-head{gap:.7rem;align-items:flex-start}
  .engineer-page .finding-study .disc-head h3{font-size:1.125rem}
  .engineer-page .finding-study .disc-badge{width:28px;height:28px;font-size:.8125rem;flex:none}
  .engineer-page .finding-optimization > .opt-head{font-size:1rem}
}
@media(prefers-reduced-motion:reduce){.findings-picker button,.optimization-picker button{transition:none}}

/* An automatic research story: goal, agent action, experiment, verified gain. */
.discovery-lab{--study-duration:6000ms;--study-play-state:paused}
.discovery-lab[data-playing=true]{--study-play-state:running}
.discovery-steps button small{font-size:.75rem}
.discovery-steps button b{font-weight:600}
.discovery-steps button::after{content:'';position:absolute;bottom:0;left:0;width:100%;height:2px;background:var(--sf-blue);transform:scaleX(0);transform-origin:left}
.discovery-steps button[aria-pressed=true]::after{animation:study-progress var(--study-duration) linear both;animation-play-state:var(--study-play-state)}
.discovery-navigation .process-playback{display:flex;gap:.75rem;align-items:center;color:var(--text-muted);font-size:.75rem}
.discovery-navigation [data-study-autoplay]{display:inline-flex;align-items:center;gap:.4rem;min-height:34px;padding:.35rem .6rem;border:1px solid #cbdfee;background:#fff;color:var(--sf-blue-deep);font-size:.75rem}
.autoplay-icon{font-size:.6875rem}
.process-handoff{display:flex;align-items:baseline;gap:.75rem;padding:.85rem 1rem;margin-top:1rem;border-left:3px solid var(--sf-blue);background:#edf6fd;border-radius:0 8px 8px 0}
.process-handoff > span:first-child{font-size:.75rem;line-height:1.5;color:var(--text-muted)}
.process-handoff strong{font-size:.875rem;font-weight:500;line-height:1.5;color:var(--sf-navy)}
.handoff-arrow{margin-left:auto;color:var(--sf-blue)}
.discovery-experiment{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:2rem;min-height:324px;border:1px solid #d4e5f1;border-radius:14px;background:#f4f9fd;padding:1.6rem;align-items:center}
.experiment-label{display:block;font-size:.8125rem;line-height:1.5;font-weight:500;color:var(--sf-navy);margin-bottom:1rem}
.paired-round{display:flex;align-items:center;gap:.5rem;padding:.7rem 0;border-top:1px solid #d4e3ee;flex-wrap:wrap}
.paired-round > span{font-size:.75rem;color:var(--text-muted);margin-right:auto}
.paired-round > b{font-size:.8125rem;font-weight:500;color:var(--sf-blue-deep);background:#fff;border:1px solid #c7deef;border-radius:5px;padding:.35rem .45rem}
.paired-round > i{font-size:.875rem;font-style:normal;color:#92b4ce}
.experiment-pairing > p,.experiment-comparison > p,.hashing-comparison > p{font-size:.75rem;line-height:1.6;color:var(--text-muted);margin:.8rem 0 0}
.experiment-comparison,.hashing-comparison{min-width:0;border-left:1px solid #d1e2ef;padding-left:1.5rem}
.comparison-row{margin-top:1rem}
.comparison-row > span{display:flex;justify-content:space-between;gap:.5rem;font-size:.8125rem;color:var(--text-secondary);line-height:1.5;margin-bottom:.4rem}
.comparison-row b{font-size:.875rem;font-weight:500;color:var(--sf-blue-deep);font-variant-numeric:tabular-nums}
.comparison-track{height:22px;border-radius:5px;background:#e0ebf3;overflow:hidden}
.comparison-track i{display:block;height:100%;width:100%;background:#aec5d7;border-radius:5px;transform-origin:left}
.comparison-track .candidate-bar{background:linear-gradient(90deg,#0176d3,#3ba8fa)}
.hashing-comparison > div{display:flex;align-items:baseline;justify-content:space-between;gap:.6rem;padding:.5rem 0;border-top:1px solid #d3e4f1}
.hashing-comparison > div > span{font-size:.75rem;line-height:1.5;color:var(--text-secondary)}
.hashing-comparison b{font-size:1rem;font-weight:500;color:var(--sf-blue-deep);font-variant-numeric:tabular-nums}
.discovery-proof{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.15fr);gap:2rem;align-items:center;min-height:324px;padding:1.7rem;background:linear-gradient(120deg,#eaf6ff,#f8fcff)}
.proof-outcome > span{display:block;color:var(--sf-blue-deep);font-size:.75rem;text-transform:uppercase;letter-spacing:.08em;line-height:1.5;margin-bottom:.75rem}
.proof-outcome > small{display:block;color:var(--sf-blue-deep);font-size:.9375rem;line-height:1.5;margin-bottom:.15rem}
.proof-outcome > strong{display:block;font-size:clamp(2.5rem,4.8vw,3.8rem);font-weight:600;line-height:1.1;letter-spacing:-.055em;color:var(--sf-blue-deep);font-variant-numeric:tabular-nums}
.proof-outcome > b{display:block;font-size:1rem;font-weight:500;line-height:1.5;color:var(--sf-navy);margin-top:.6rem}
.proof-outcome > p{font-size:.8125rem;line-height:1.65;color:var(--text-secondary);margin:.65rem 0 0}
.discovery-proof .proof-checks{grid-template-columns:minmax(0,1fr);border-left:1px solid #c8dfed;padding-left:1.5rem;gap:1.15rem}
.discovery-proof .proof-checks b{font-size:.875rem}
.discovery-proof .proof-checks p > span{font-size:.8125rem}
@keyframes study-progress{from{transform:scaleX(0)}to{transform:scaleX(1)}}
@keyframes study-bars{from{transform:scaleX(.05)}to{transform:scaleX(1)}}
@keyframes study-pair{0%,100%{border-color:#c7deef;background:#fff}30%,65%{border-color:#5daae2;background:#dfeffc}}
@media(prefers-reduced-motion:no-preference){
  .discovery-lab[data-step=experiment] .comparison-track i{animation:study-bars 1s ease both}
  .discovery-lab[data-step=experiment] .paired-round b{animation:study-pair 3s ease infinite;animation-play-state:var(--study-play-state)}
  .discovery-lab[data-step=experiment] .paired-round b:last-child{animation-delay:.6s}
  .discovery-lab[data-step=experiment] .paired-round:nth-child(3) b{animation-delay:1.5s}
  .discovery-lab[data-step=experiment] .paired-round:nth-child(3) b:last-child{animation-delay:2.1s}
}
@media(max-width:900px){
  .discovery-steps{padding:1rem;gap:.4rem}
  .discovery-steps button{padding:.7rem .55rem;gap:.5rem}
  .discovery-steps small{display:none}
  .discovery-steps b{font-size:.8125rem}
  .story-step-number{width:26px;height:26px;flex:none}
  .discovery-experiment{gap:1.2rem;padding:1.2rem}
  .experiment-comparison,.hashing-comparison{padding-left:1.2rem}
}
@media(max-width:640px){
  .discovery-steps{grid-template-columns:repeat(2,minmax(0,1fr));padding:1rem;gap:.5rem}
  .discovery-steps button{flex-direction:row;text-align:left;justify-content:flex-start;padding:.7rem .65rem}
  .discovery-steps b{max-width:none}
  .discovery-experiment,.discovery-proof{grid-template-columns:minmax(0,1fr);padding:1.15rem;gap:1.4rem;min-height:0}
  .experiment-comparison,.hashing-comparison,.discovery-proof .proof-checks{padding:1.1rem 0 0;border-left:0;border-top:1px solid #cee1ee}
  .proof-outcome > strong{font-size:2.85rem}
  .process-handoff{align-items:flex-start;flex-direction:column;gap:.3rem;padding:.8rem .85rem}
  .handoff-arrow{display:none}
  .discovery-navigation .process-playback{order:-1;justify-content:center;flex-basis:100%;margin-bottom:.3rem}
}
@media(prefers-reduced-motion:reduce){.discovery-steps button[aria-pressed=true]::after{animation:none;transform:scaleX(1)}}