:root {
  --paper: #e9eef0;
  --grid: #d3dde2;
  --grid-major: #c2cfd6;
  --ink: #14304a;
  --ink-2: #4a6175;
  --attack: #d9481f;
  --hold: #1b7f66;
  --card: #f4f7f8;
  --sans: "IBM Plex Sans", system-ui, sans-serif;
  --display: "Archivo", "IBM Plex Sans", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #0f1e2b; --grid: #162a3a; --grid-major: #1d3548;
    --ink: #d7e4ee; --ink-2: #93a9bb; --attack: #ff7a50; --hold: #4fd1a8; --card: #132535;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  color: var(--ink);
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid-major) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-major) 1px, transparent 1px),
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 120px 120px, 120px 120px, 24px 24px, 24px 24px;
  font: 400 1.0625rem/1.6 var(--sans);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--attack); }
:focus-visible { outline: 2px solid var(--attack); outline-offset: 3px; }
.skip { position: absolute; left: -999px; top: 0; background: var(--ink); color: var(--paper); padding: .5rem 1rem; z-index: 10; }
.skip:focus { left: 1rem; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* top bar */
.top {
  max-width: 76rem; margin: 0 auto; padding: 1.25rem 1rem;
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
}
.mark {
  font: 800 1.1rem/1 var(--display); font-stretch: 125%;
  text-decoration: none; border: 2px solid var(--ink); padding: .35rem .45rem;
}
.top nav { display: flex; gap: 1.25rem; flex-wrap: wrap; font-size: .95rem; }
.top nav a { text-decoration: none; }
.top nav a:hover { text-decoration: underline; }

main { max-width: 76rem; margin: 0 auto; padding: 0 1rem; }

/* hero */
.hero { padding: 3rem 0 4rem; }
.intro { max-width: 46rem; }
h1 {
  font: 800 clamp(3rem, 9vw, 7.5rem)/.9 var(--display);
  font-stretch: 62%;
  letter-spacing: -.01em;
  margin: 0 0 1.5rem;
}
.lede { font-size: clamp(1.2rem, 2.2vw, 1.5rem); line-height: 1.4; margin: 0 0 1rem; max-width: 36em; }
.meta { color: var(--ink-2); margin: 0; max-width: 40em; }

/* cross-section figure */
.xsection {
  margin: 3.5rem 0 0;
  border: 1.5px solid var(--ink);
  background: var(--card);
  padding: 1.25rem;
}
.xsection figcaption { font-size: .95rem; color: var(--ink-2); margin-bottom: 1rem; }
.fig { font-family: var(--mono); color: var(--ink); margin-right: .4rem; }

.attacks { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 1.5rem; }
.attacks button {
  font: 500 .9rem/1 var(--sans);
  color: var(--attack);
  background: transparent;
  border: 1.5px dashed var(--attack);
  padding: .55rem .8rem;
  cursor: pointer;
}
.attacks button:hover, .attacks button[aria-pressed="true"] { background: var(--attack); color: var(--card); border-style: solid; }

.stack { position: relative; padding-top: 2.25rem; }
.lane { position: absolute; left: 0; right: 0; top: .6rem; height: 1rem; }
.trail {
  position: absolute; left: 0; top: 50%; height: 0;
  width: calc(var(--p, 0) * 100%);
  border-top: 2px dashed var(--attack);
  transition: width .9s cubic-bezier(.5, 0, .2, 1);
}
.token {
  position: absolute; top: 50%; left: calc(var(--p, 0) * 100%);
  width: .9rem; height: .9rem; margin: -.45rem 0 0 -.45rem;
  background: var(--attack); transform: rotate(45deg);
  opacity: 0;
  transition: left .9s cubic-bezier(.5, 0, .2, 1), opacity .2s;
}
.stack.running .token { opacity: 1; }

.layers {
  list-style: none; margin: 0; padding: 0;
  display: grid; grid-template-columns: repeat(7, 1fr);
  border-left: 1.5px solid var(--ink);
}
.layers li {
  border-right: 1.5px solid var(--ink);
  border-top: 1.5px solid var(--ink);
  border-bottom: 1.5px solid var(--ink);
  padding: .9rem .8rem 1.1rem;
  min-height: 9.5rem;
  position: relative;
  transition: background-color .3s;
}
.layers li:nth-child(even) {
  background-image: repeating-linear-gradient(135deg, transparent 0 7px, var(--grid) 7px 8px);
}
.layers h3 { font: 700 1rem/1.15 var(--display); font-stretch: 100%; margin: 0 0 .4rem; }
.layers p { font-size: .85rem; line-height: 1.4; color: var(--ink-2); margin: 0; }
.layers li.blocked { background: var(--hold); background-image: none; }
.layers li.blocked h3, .layers li.blocked p { color: var(--card); }
.layers li.blocked::after {
  content: "Stopped here";
  position: absolute; left: .8rem; bottom: .5rem;
  font: 500 .75rem/1 var(--mono); color: var(--card);
}
.layers li.blocked p { margin-bottom: 1rem; }

.readout { margin: 1rem 0 0; min-height: 3.2em; max-width: 60em; }
.readout b { color: var(--hold); }

/* sheets */
.sheet { border-top: 1.5px solid var(--ink); padding: 3rem 0 4rem; }
.sheet-title { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: flex-start; gap: 1.5rem; margin-bottom: 2.5rem; }
h2 { font: 800 clamp(2.2rem, 5vw, 3.5rem)/1 var(--display); font-stretch: 75%; margin: 0; }
.titleblock { display: grid; grid-template-columns: repeat(3, auto); border: 1.5px solid var(--ink); margin: 0; background: var(--card); }
.titleblock div { padding: .45rem .8rem; border-left: 1.5px solid var(--ink); }
.titleblock div:first-child { border-left: 0; }
.titleblock dt { font: 400 .72rem/1.2 var(--mono); color: var(--ink-2); }
.titleblock dd { margin: 0; font-size: .92rem; font-weight: 500; }

h3 { font: 700 1.25rem/1.25 var(--display); font-stretch: 90%; margin: 0 0 1rem; }
.cols { display: grid; grid-template-columns: 1fr 1fr; gap: 3rem; }
.spec { list-style: none; padding: 0; margin: 0; }
.spec li { padding: .8rem 0 .8rem 1.4rem; border-top: 1px solid var(--grid-major); position: relative; max-width: 38em; }
.spec li::before { content: ""; position: absolute; left: 0; top: 1.35rem; width: .55rem; height: 1.5px; background: var(--ink); }
.spec b { font-weight: 600; }

.research { display: grid; grid-template-columns: minmax(14rem, 1fr) 2fr; gap: 3rem; align-items: start; }
.research p { max-width: 38em; }
.finding { border: 1.5px solid var(--attack); padding: 1.25rem; background: var(--card); }
.finding .big { font: 800 4.5rem/1 var(--display); font-stretch: 62%; color: var(--attack); margin: 0 0 .5rem; }
.finding p { margin: 0; font-size: .95rem; }
.tools { font: 400 .85rem/1.4 var(--mono); color: var(--ink-2); }
.interests-h { margin-top: 3rem; }
.interests { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; margin: 0; border: 1.5px solid var(--ink); background: var(--card); }
.interests div { padding: 1rem; border-left: 1.5px solid var(--ink); }
.interests div:first-child { border-left: 0; }
.interests dt { font-weight: 600; margin-bottom: .3rem; }
.interests dd { margin: 0; font-size: .95rem; color: var(--ink-2); }

.projects { display: grid; grid-template-columns: repeat(2, 1fr); gap: 2rem 3rem; }
.projects article { border-top: 3px solid var(--ink); padding-top: 1rem; }
.projects p { margin: 0 0 .75rem; }

.schedule { width: 100%; border-collapse: collapse; background: var(--card); border: 1.5px solid var(--ink); }
.schedule th, .schedule td { text-align: left; padding: .75rem 1rem; border-bottom: 1px solid var(--grid-major); vertical-align: top; }
.schedule th { font-weight: 600; width: 30%; }
.schedule td:last-child { font-family: var(--mono); font-size: .85rem; color: var(--ink-2); white-space: nowrap; text-align: right; }
.toolkit { margin-top: 1.5rem; max-width: 60em; color: var(--ink-2); }
.toolkit b { color: var(--ink); }

.contact p { font-size: 1.25rem; max-width: 30em; margin: 1rem 0 1.5rem; }
.contact ul { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 1rem 2rem; font: 600 1.15rem/1.3 var(--display); }

.foot { max-width: 76rem; margin: 0 auto; padding: 2rem 1rem 3rem; border-top: 1.5px solid var(--ink); font-size: .85rem; color: var(--ink-2); }


/* ---------- added: key figures as drawing dimensions ---------- */
.dims { list-style: none; margin: 3rem 0 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); max-width: 60rem; }
.dims li { position: relative; padding: 1.4rem 1rem 0 0; }
.dims li::before { content: ""; position: absolute; left: 0; right: 1rem; top: .45rem; border-top: 1px solid var(--ink-2); }
.dims li::after { content: ""; position: absolute; left: 0; top: 0; height: .9rem; border-left: 1px solid var(--ink-2); box-shadow: calc(100% - 1rem) 0 0 0 transparent; }
.dims b { display: block; font: 800 clamp(1.8rem, 3.4vw, 2.6rem)/1 var(--display); font-stretch: 70%; margin-bottom: .35rem; }
.dims span { display: block; font-size: .9rem; line-height: 1.4; color: var(--ink-2); max-width: 16em; }

/* ---------- research ---------- */
.statement { max-width: 46rem; margin-bottom: 3rem; }
.statement p { margin: 0 0 1rem; }
.statement-lead { font-size: clamp(1.15rem, 2vw, 1.35rem); line-height: 1.5; color: var(--ink); }
.narrow { max-width: 44rem; margin: 0 0 2.5rem; }
.sub { font-size: 1.05rem; font-stretch: 110%; margin: 3rem 0 1.25rem; padding-bottom: .4rem; border-bottom: 1px dashed var(--ink-2); }
.sheet-title + .sub, .statement + .sub { margin-top: 0; }

.flow { list-style: none; margin: 0 0 3rem; padding: 0; display: grid; grid-template-columns: repeat(5, 1fr); gap: 1.6rem; counter-reset: f; }
.flow li { position: relative; counter-increment: f; border: 1.5px solid var(--ink); background: var(--card); padding: .8rem .85rem 1rem; }
.flow li::before { content: counter(f); font: 500 .75rem/1 var(--mono); color: var(--ink-2); display: block; margin-bottom: .45rem; }
.flow li:not(:last-child)::after { content: ""; position: absolute; top: 50%; right: -1.6rem; width: 1.6rem; border-top: 1.5px solid var(--ink); }
.flow li.hostile { border: 1.5px dashed var(--attack); }
.flow li.hostile b { color: var(--attack); }
.flow b { display: block; font: 700 1rem/1.2 var(--display); margin-bottom: .3rem; }
.flow span { font-size: .88rem; line-height: 1.4; color: var(--ink-2); display: block; }

.setup { border-collapse: collapse; width: 100%; max-width: 34rem; margin-top: 1.5rem; background: var(--card); border: 1.5px solid var(--ink); }
.setup caption { text-align: left; font: 500 .8rem/1 var(--mono); color: var(--ink-2); padding-bottom: .5rem; }
.setup th, .setup td { text-align: left; padding: .5rem .8rem; border-top: 1px solid var(--grid-major); font-size: .93rem; }
.setup th { font-weight: 400; color: var(--ink-2); }
.setup td { font-weight: 600; }

.cols.three { grid-template-columns: repeat(3, 1fr); margin-top: 3rem; }
.prior { margin-top: 3.5rem; border: 1.5px solid var(--ink); background: var(--card); padding: 1.5rem; }
.prior header { margin-bottom: .75rem; }
.prior header .tools { margin: .35rem 0 0; }
.prior > p { max-width: 44em; }

/* ---------- questions ---------- */
.questions { display: grid; grid-template-columns: repeat(3, 1fr); border: 1.5px solid var(--ink); background: var(--card); }
.questions article { padding: 1.4rem; border-left: 1.5px solid var(--ink); }
.questions article:first-child { border-left: 0; }
.questions p { color: var(--ink-2); font-size: .95rem; }
.questions ul { margin: 0; padding: 0; list-style: none; }
.questions li { padding: .7rem 0 0 1.3rem; position: relative; border-top: 1px dashed var(--grid-major); margin-top: .7rem; }
.questions li::before { content: "?"; position: absolute; left: 0; top: .7rem; font: 700 .95rem/1.6 var(--display); color: var(--attack); }

/* ---------- case cards ---------- */
.cases { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border-top: 1.5px solid var(--ink); border-left: 1.5px solid var(--ink); }
.cases article { border-right: 1.5px solid var(--ink); border-bottom: 1.5px solid var(--ink); background: var(--card); padding: 1.1rem 1.1rem 1.25rem; }
.cases h4 { font: 700 1.05rem/1.25 var(--display); margin: 0 0 .8rem; }
.cases dl { margin: 0; display: grid; grid-template-columns: 4.6rem 1fr; gap: .45rem .6rem; }
.cases dt { font: 400 .74rem/1.9 var(--mono); color: var(--ink-2); }
.cases dd { margin: 0; font-size: .92rem; line-height: 1.45; }
.cases dd.res { font-weight: 600; color: var(--hold); }

.schedule.attack th { width: 26%; }
.schedule.attack td:last-child { font-family: var(--sans); font-size: .95rem; color: var(--ink); white-space: normal; text-align: left; }
.coursework { color: var(--ink-2); }
.coursework b { color: var(--ink); }
.schedule td a { color: var(--ink); font-weight: 600; }

.toolkit-grid { display: grid; grid-template-columns: repeat(3, 1fr); margin: 0; border-top: 1.5px solid var(--ink); border-left: 1.5px solid var(--ink); }
.toolkit-grid div { padding: .9rem 1rem; border-right: 1.5px solid var(--ink); border-bottom: 1.5px solid var(--ink); background: var(--card); }
.toolkit-grid dt { font: 400 .75rem/1.3 var(--mono); color: var(--ink-2); margin-bottom: .3rem; }
.toolkit-grid dd { margin: 0; font-size: .93rem; }

@media (max-width: 1000px) {
  .flow { grid-template-columns: 1fr; gap: 1rem; }
  .flow li:not(:last-child)::after { top: auto; bottom: -1rem; right: auto; left: 1.5rem; width: 0; height: 1rem; border-top: 0; border-left: 1.5px solid var(--ink); }
  .cases, .toolkit-grid { grid-template-columns: 1fr 1fr; }
  .dims { row-gap: 1.5rem; }
}
@media (max-width: 900px) {
  .cols.three, .questions { grid-template-columns: 1fr; }
  .questions article { border-left: 0; border-top: 1.5px solid var(--ink); }
  .questions article:first-child { border-top: 0; }
}
@media (max-width: 640px) {
  .cases, .toolkit-grid, .projects { grid-template-columns: 1fr; }
}

/* responsive */
@media (max-width: 900px) {
  .cols, .research { grid-template-columns: 1fr; gap: 2rem; }
  .projects, .interests { grid-template-columns: 1fr; }
  .interests div { border-left: 0; border-top: 1.5px solid var(--ink); }
  .interests div:first-child { border-top: 0; }
  .titleblock { grid-template-columns: 1fr; width: 100%; }
  .titleblock div { border-left: 0; border-top: 1.5px solid var(--ink); }
  .titleblock div:first-child { border-top: 0; }

  /* cross-section turns vertical: the attack travels down the stack */
  .stack { padding-top: 0; padding-left: 2rem; }
  .lane { top: 0; bottom: 0; left: .5rem; right: auto; width: 1rem; height: auto; }
  .trail { left: 50%; top: 0; width: 0; height: calc(var(--p, 0) * 100%); border-top: 0; border-left: 2px dashed var(--attack); transition-property: height; }
  .token { left: 50%; top: calc(var(--p, 0) * 100%); transition-property: top, opacity; }
  .layers { grid-template-columns: 1fr; border-left: 1.5px solid var(--ink); border-top: 1.5px solid var(--ink); }
  .layers li { min-height: 0; border-top: 0; }
  .layers li.blocked::after { left: auto; right: .8rem; bottom: auto; top: .9rem; }
  .layers li.blocked p { margin-bottom: 0; }
  .schedule th { width: auto; }
  .schedule, .schedule tbody, .schedule tr, .schedule th, .schedule td { display: block; }
  .schedule th { padding-bottom: 0; border: 0; }
  .schedule td:last-child { text-align: left; padding-top: 0; }
}
@media (prefers-reduced-motion: reduce) {
  .trail, .token, .layers li { transition: none !important; }
}

/* AI emphasis */
.role { font: 500 .95rem/1.3 var(--mono); color: var(--attack); margin: 0 0 .8rem; }
.layers li.model { border-left: 3px double var(--ink); background-image: none; background-color: color-mix(in srgb, var(--attack) 7%, var(--card)); }
.layers li.model.reached { background-color: var(--attack); }
.layers li.reached { background: var(--attack); background-image: none; }
.layers li.reached h3, .layers li.reached p { color: var(--card); }
.layers li.reached::after { content: "Open problem"; position: absolute; left: .8rem; bottom: .5rem; font: 500 .75rem/1 var(--mono); color: var(--card); }
.layers li.reached p { margin-bottom: 1rem; }
.attacks button.ai { border-style: solid; }
.readout b.open { color: var(--attack); }
@media (max-width: 900px) {
  .layers li.model { border-left: 0; border-top: 3px double var(--ink); }
  .layers li.reached::after { left: auto; right: .8rem; bottom: auto; top: .9rem; }
  .layers li.reached p { margin-bottom: 0; }
}

/* ---------- SOP additions ---------- */
.finding .insight { margin-top: 1rem; padding-top: 1rem; border-top: 1px dashed var(--attack); }
.finding .insight b { color: var(--attack); }
.llm { margin-top: 3.5rem; border: 1.5px solid var(--ink); background: var(--card); padding: 1.5rem; }
.llm-head p { max-width: 44em; margin: .25rem 0 1.5rem; color: var(--ink-2); }
.llm-head h3 { margin-bottom: .25rem; }
.mini { font: 500 .8rem/1.2 var(--mono); color: var(--ink-2); margin: 0 0 .5rem; }
.llm .cols { gap: 2.5rem; margin-bottom: 2rem; }
.problems { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.problems article { border: 1.5px dashed var(--attack); padding: 1rem; background: var(--paper); }
.problems svg { width: 100%; height: auto; display: block; margin-bottom: .75rem; }
.problems h5 { font: 700 1rem/1.25 var(--display); margin: 0 0 .4rem; }
.problems p { font-size: .9rem; line-height: 1.5; margin: 0; color: var(--ink-2); }
.sv-box { fill: var(--card); stroke: var(--ink); stroke-width: 1.5; }
.sv-hostile { stroke: var(--attack); stroke-dasharray: 4 3; }
.sv-line { stroke: var(--ink); stroke-width: 1.5; fill: none; }
.sv-dash { stroke: var(--attack); stroke-dasharray: 4 3; }
.sv-t { font: 500 11px var(--sans); fill: var(--ink); text-anchor: middle; }
.sv-s { font-size: 9.5px; fill: var(--ink-2); }
.sv-red { fill: var(--attack); }
@media (max-width: 900px) { .problems { grid-template-columns: 1fr; } }

/* ---------- polish: CAD crosshair on the hero ---------- */
.hero { position: relative; }
.cad { position: absolute; inset: 0 calc(50% - 50vw); pointer-events: none; opacity: 0; transition: opacity .2s; z-index: 0; overflow: hidden; }
.hero.tracking .cad { opacity: 1; }
.hero > :not(.cad) { position: relative; z-index: 1; }
.cad-x, .cad-y { position: absolute; background: var(--attack); opacity: .35; }
.cad-x { left: 0; right: 0; height: 1px; top: var(--cy, 0); }
.cad-y { top: 0; bottom: 0; width: 1px; left: var(--cx, 0); }
.cad-label { position: absolute; left: var(--cx, 0); top: var(--cy, 0); transform: translate(10px, 8px); font: 500 .7rem/1 var(--mono); color: var(--attack); background: var(--paper); padding: 2px 4px; white-space: nowrap; }
@media (pointer: fine) { .hero.tracking { cursor: crosshair; } .hero.tracking button, .hero.tracking a { cursor: pointer; } }

/* ---------- polish: one load sequence, plotted like a drawing ---------- */
@media (prefers-reduced-motion: no-preference) {
  .role { animation: plot-fade .5s .05s both; }
  h1 { animation: plot-wipe .9s .1s cubic-bezier(.6, 0, .2, 1) both; }
  .lede { animation: plot-fade .6s .55s both; }
  .meta { animation: plot-fade .6s .7s both; }
  .dims li::before { transform-origin: left; animation: plot-line .7s cubic-bezier(.6, 0, .2, 1) both; }
  .dims li:nth-child(1)::before { animation-delay: .8s; }
  .dims li:nth-child(2)::before { animation-delay: .9s; }
  .dims li:nth-child(3)::before { animation-delay: 1s; }
  .dims li:nth-child(4)::before { animation-delay: 1.1s; }
  .dims b, .dims span { animation: plot-fade .5s 1.2s both; }
  .xsection { animation: plot-fade .6s 1.3s both; }
}
@keyframes plot-wipe { from { clip-path: inset(0 100% 0 0); } to { clip-path: inset(0 0 0 0); } }
@keyframes plot-line { from { transform: scaleX(0); } to { transform: scaleX(1); } }
@keyframes plot-fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* ---------- polish: registration marks on hover ---------- */
.cases article, .problems article, .projects article { position: relative; transition: background-color .2s; }
.cases article::before, .cases article::after,
.problems article::before, .problems article::after {
  content: ""; position: absolute; width: 10px; height: 10px; opacity: 0; transition: opacity .2s, transform .2s;
}
.cases article::before, .problems article::before { top: 5px; left: 5px; border-top: 2px solid var(--attack); border-left: 2px solid var(--attack); transform: translate(4px, 4px); }
.cases article::after, .problems article::after { bottom: 5px; right: 5px; border-bottom: 2px solid var(--attack); border-right: 2px solid var(--attack); transform: translate(-4px, -4px); }
.cases article:hover::before, .cases article:hover::after,
.problems article:hover::before, .problems article:hover::after { opacity: 1; transform: none; }
.cases article:hover { background: var(--paper); }
.projects article:hover h3 a { color: var(--attack); }

@media (max-width: 640px) { .dims { grid-template-columns: 1fr; } }