/* =====================================================================
   Agent Harness Engineering: A Survey. Project page styles.
   Quiet, white-paper aesthetic. Inspired by typical academic project pages.
   ===================================================================== */

:root {
  --bg:        #ffffff;
  --bg-alt:    #f7f7f3;
  --ink:       #1f2328;
  --ink-soft:  #404953;
  --muted:     #6a727b;
  --line:      #e5e0d2;
  --line-soft: #edeae0;
  --link:      #0a59a4;
  --link-hov:  #08407a;
  --accent:    #114a6f;
  --code-bg:   #f6f8fa;
  --code-ink:  #1f2328;

  --maxw:        1080px;
  --maxw-narrow: 820px;

  --r:    6px;
  --t:    160ms ease-out;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.72;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

a { color: var(--link); text-decoration: none; }
a:hover { color: var(--link-hov); text-decoration: underline; text-underline-offset: 3px; }

em { font-style: italic; }
sup { font-size: 0.72em; vertical-align: super; line-height: 0; }

img { max-width: 100%; display: block; }

p { margin: 0 0 1em; }

h2 {
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.012em;
  color: var(--ink);
  margin: 0 0 0.6em;
}

/* Containers ----------------------------------------------------------- */

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}
.container--narrow {
  max-width: var(--maxw-narrow);
}

/* Hero ---------------------------------------------------------------- */

.hero {
  padding: 64px 0 32px;
  text-align: center;
  background: var(--bg);
}

.title {
  font-family: 'Inter', system-ui, sans-serif;
  font-size: clamp(28px, 4.2vw, 40px);
  font-weight: 700;
  letter-spacing: -0.022em;
  line-height: 1.18;
  color: var(--ink);
  margin: 0 0 14px;
}

.venue {
  font-size: 14px;
  color: var(--muted);
  margin: 0 0 26px;
  letter-spacing: 0.02em;
}

.authors {
  font-size: 16.5px;
  line-height: 1.75;
  color: var(--ink);
  margin: 0 auto 12px;
  max-width: 880px;
  /* Let the browser balance line widths so no name is orphaned on
     its own line (graceful fallback to default wrapping on browsers
     that don't yet support text-wrap: balance). */
  text-wrap: balance;
}
.authors a {
  color: var(--link);
  font-weight: 500;
}
.authors sup {
  color: var(--muted);
  font-weight: 400;
}

.affil {
  font-size: 13.5px;
  color: var(--ink-soft);
  margin: 0 auto 22px;
  max-width: 880px;
  line-height: 1.75;
  text-wrap: balance;
}
.affil sup { color: var(--muted); }
.affil-note { color: var(--muted); font-size: 13px; }

/* Buttons ------------------------------------------------------------- */

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin: 26px 0 36px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #1f2328;
  color: #f6f7f8;
  padding: 9px 18px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.01em;
  transition: background var(--t), transform var(--t);
  border: 1px solid #1f2328;
}
.btn:hover {
  background: #2b3138;
  color: #fff;
  text-decoration: none;
  transform: translateY(-1px);
}
.btn .ic {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  line-height: 1;
}
.btn .ic svg { display: block; }

/* Teaser image -------------------------------------------------------- */

.teaser {
  margin: 18px auto 0;
  max-width: 880px;
}
.teaser img {
  margin: 0 auto;
  border-radius: 4px;
  border: 1px solid var(--line-soft);
}
.teaser figcaption,
figure figcaption {
  font-style: italic;
  font-size: 14px;
  color: var(--muted);
  text-align: center;
  margin-top: 14px;
  line-height: 1.65;
  /* Avoid orphaned single words on the last line when captions wrap. */
  text-wrap: balance;
}

/* Sections ------------------------------------------------------------ */

.section {
  padding: 64px 0;
  border-top: 1px solid var(--line-soft);
}
.section--alt {
  background: var(--bg-alt);
}

/* Eyebrow + serif headline -------------------------------------------- */

.eyebrow {
  display: block;
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-O);
  margin: 0 0 16px;
}

.headline {
  font-family: 'Noto Serif', Georgia, 'Times New Roman', serif;
  font-size: clamp(30px, 4.2vw, 46px);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.012em;
  color: var(--ink);
  margin: 0;
  /* Let the browser balance line widths so the headline doesn't
     leave a single short word on the last line. */
  text-wrap: balance;
}

.section-heading {
  margin: 0 0 32px;
}
.section-heading .headline { max-width: 22ch; }

/* Two-column Abstract layout */

.abstract-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  gap: 56px;
  align-items: start;
}
@media (max-width: 880px) {
  .abstract-grid { grid-template-columns: 1fr; gap: 26px; }
}
.abstract-headline .headline { max-width: 18ch; }
.abstract-prose p {
  font-size: 16px;
  color: var(--ink-soft);
  line-height: 1.78;
  margin: 0 0 16px;
}
.abstract-prose p:last-child { margin-bottom: 0; }
.abstract-prose strong { color: var(--ink); }

/* Three Claims grid */

.claims {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 8px;
}
@media (max-width: 880px) {
  .claims { grid-template-columns: 1fr; }
}
.claim {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 22px 24px;
  display: flex;
  flex-direction: column;
}
.claim__label {
  display: block;
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-O);
  margin: 0 0 12px;
}
.claim h3 {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.32;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.claim p {
  margin: 0;
  font-size: 14.5px;
  color: var(--ink-soft);
  line-height: 1.7;
}

/* Figures inside sections */
.section figure {
  margin: 28px 0;
}
.section figure img {
  margin: 0 auto;
  border-radius: 4px;
}

/* Wide figure variant. Used by the timeline figure so the chart
   breaks out of the narrow text column and gets visual prominence. */
.figure--wide {
  margin: 18px auto 0;
  padding: 18px 22px 14px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 1px 0 rgba(31, 35, 40, 0.03);
}
.figure--wide img {
  width: 100%;
  height: auto;
  margin: 0 auto;
  border-radius: 4px;
}
.figure--wide figcaption {
  margin-top: 14px;
}
@media (max-width: 640px) {
  .figure--wide { padding: 12px 14px 10px; }
}

/* Portrait-orientation figure (taxonomy tree). Lives in the wider
   container but is capped so the inner box-text stays readable without
   the figure dominating the page. */
.figure--tree {
  margin: 36px auto 0;
  padding: 20px 24px 16px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 1px 0 rgba(31, 35, 40, 0.03);
  max-width: 900px;
}
.figure--tree img {
  width: 100%;
  height: auto;
  margin: 0 auto;
  border-radius: 4px;
}
.figure--tree figcaption {
  margin-top: 14px;
}
@media (max-width: 640px) {
  .figure--tree { padding: 12px 14px 10px; margin-top: 24px; }
}

/* Phases list --------------------------------------------------------- */

.phases {
  list-style: none;
  padding: 0;
  margin: 18px 0 0;
  display: grid;
  gap: 14px;
}
.phases li {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: 18px 20px;
  font-size: 15.5px;
  color: var(--ink-soft);
  line-height: 1.7;
  display: grid;
  grid-template-columns: 100px minmax(0, 1fr);
  gap: 18px;
  align-items: baseline;
}
.phases strong { color: var(--ink); }
.phases__year {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.04em;
  padding: 2px 8px;
  border-radius: 3px;
  background: var(--bg-alt);
  justify-self: start;
}
.phases__body { color: var(--ink-soft); }
@media (max-width: 520px) {
  .phases li {
    grid-template-columns: 1fr;
    gap: 6px;
  }
}

/* Section--alt overrides. Keep sub-cards readable on alt background. */
.section--alt .phases li {
  background: #fff;
}

/* Layers list --------------------------------------------------------- */

.layers {
  list-style: none;
  padding: 0;
  margin: 22px 0 0;
  display: grid;
  gap: 10px;
}
.layers li {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 14px;
  align-items: start;
  padding: 16px 18px;
  background: #fff;
  border: 1px solid var(--line);
  border-left: 4px solid var(--lc, var(--line));
  border-radius: var(--r);
  font-size: 15.5px;
  color: var(--ink-soft);
  line-height: 1.7;
}
.layers__id {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-weight: 600;
  font-size: 14px;
  width: 28px;
  height: 28px;
  border-radius: 4px;
  background: color-mix(in srgb, var(--lc) 14%, #fff);
  color: var(--lc);
  border: 1px solid color-mix(in srgb, var(--lc) 28%, transparent);
  margin-top: 1px;
}
.layers strong { color: var(--ink); font-weight: 600; }

/* Count table --------------------------------------------------------- */

.counts {
  width: 100%;
  border-collapse: collapse;
  margin: 22px 0 18px;
  font-size: 15px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--r);
  overflow: hidden;
}
.counts th, .counts td {
  padding: 11px 14px;
  text-align: left;
  vertical-align: middle;
  border-bottom: 1px solid var(--line-soft);
}
.counts thead th {
  background: var(--bg-alt);
  font-weight: 600;
  color: var(--ink-soft);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.counts tbody tr:last-child td { border-bottom: 0; }
.counts .r { text-align: right; font-variant-numeric: tabular-nums; }
.counts td:first-child {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-weight: 600;
  color: var(--ink);
  width: 70px;
  white-space: nowrap;
}
.dot {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 2px;
  background: var(--lc);
  margin-right: 6px;
  vertical-align: 0.06em;
}

.note {
  font-size: 14.5px;
  color: var(--ink-soft);
  margin-top: 12px;
}

/* Bullets ------------------------------------------------------------- */

.bullets {
  margin: 12px 0 18px;
  padding-left: 22px;
}
.bullets li {
  margin-bottom: 10px;
  font-size: 15.5px;
  color: var(--ink-soft);
  line-height: 1.72;
}
.bullets strong { color: var(--ink); }

/* Open problems ------------------------------------------------------- */

.problems {
  margin: 14px 0 0;
  padding-left: 22px;
}
.problems li {
  margin-bottom: 14px;
  font-size: 15.5px;
  color: var(--ink-soft);
  line-height: 1.72;
}
.problems strong { color: var(--ink); }
.problems::marker { color: var(--muted); }
.problems li::marker { color: var(--muted); font-variant-numeric: tabular-nums; }

/* BibTeX -------------------------------------------------------------- */

.bibtex {
  position: relative;
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: 16px 18px;
  margin-top: 18px;
}
.bibtex pre {
  margin: 0;
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: 13px;
  line-height: 1.7;
  color: var(--code-ink);
  white-space: pre;
  overflow-x: auto;
}
.bibtex__copy {
  position: absolute;
  top: 12px;
  right: 12px;
  font-family: inherit;
  font-size: 12px;
  letter-spacing: 0.02em;
  padding: 5px 12px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink-soft);
  border-radius: 4px;
  cursor: pointer;
  transition: background var(--t), color var(--t), border-color var(--t);
}
.bibtex__copy:hover {
  background: #fff;
  color: var(--ink);
  border-color: color-mix(in srgb, var(--ink) 30%, var(--line));
}
.bibtex__copy.is-copied {
  background: #1f2328;
  color: #fff;
  border-color: #1f2328;
}

/* Footer -------------------------------------------------------------- */

.footer {
  padding: 36px 0 56px;
  border-top: 1px solid var(--line-soft);
  background: var(--bg);
}
.footer p {
  margin: 0;
  font-size: 13.5px;
  color: var(--muted);
  text-align: center;
  line-height: 1.7;
}

/* Responsive tweaks --------------------------------------------------- */

@media (max-width: 640px) {
  .hero { padding: 40px 0 24px; }
  .section { padding: 44px 0; }
  .authors, .affil { font-size: 15px; }
  .layers li { grid-template-columns: 32px 1fr; gap: 10px; padding: 14px 14px; }
  .counts th, .counts td { padding: 10px 12px; font-size: 14px; }
}

/* Print --------------------------------------------------------------- */

@media print {
  .links, .footer, .bibtex__copy { display: none; }
  body { color: #000; background: #fff; }
  .section { border-color: #ddd; padding: 18px 0; }
}