:root {
  --ink: #16212e;
  --ink-soft: #5b7086;
  --paper: #ffffff;
  --surface: #eef3f9;
  --rule: #d7dee6;
  --accent: #1d5fa8;

  --measure: 68ch;
  --wide: 46rem;
}

*, *::before, *::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.0625rem;
  line-height: 1.68;
  font-synthesis-weight: none;
}

/* ---- shell ---------------------------------------------------- */

.masthead,
main,
.footer {
  max-width: var(--wide);
  margin-inline: auto;
  padding-inline: 1.5rem;
}

.masthead {
  padding-top: 3rem;
  padding-bottom: 2.5rem;
}

.masthead__name {
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: -0.005em;
  color: var(--ink);
  text-decoration: none;
}

.masthead__name:hover { color: var(--accent); }

/* Name on the left, profile link on the right, sharing a baseline. Wraps to a
   second line rather than colliding on a narrow screen. */
.masthead__top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.35rem 1rem;
}

/* Avatar sits inside the name link, so the two act as one target. */
.masthead__name {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
}

.masthead__avatar {
  display: block;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  object-fit: cover;
  background: var(--surface);
}

.masthead__link {
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.8125rem;
  color: var(--accent);
  text-decoration: none;
  white-space: nowrap;
}

.masthead__link:hover { text-decoration: underline; }

/* The page you are on is shown, not linked away from. */
.masthead__link[aria-current="page"] {
  color: var(--ink-soft);
  cursor: default;
}

.masthead__link[aria-current="page"]:hover { text-decoration: none; }

.masthead__nav {
  display: inline-flex;
  align-items: baseline;
  gap: 0.9rem;
}

.author-card__bio {
  margin: 0 0 1rem;
  max-width: var(--measure);
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--ink-soft);
}

.author-card__bio a { color: var(--accent); font-weight: 600; }

.masthead__role {
  margin: 0.35rem 0 0;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.875rem;
  color: var(--ink-soft);
}

.footer {
  margin-top: 5rem;
  padding-top: 1.5rem;
  padding-bottom: 4rem;
  border-top: 1px solid var(--rule);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.75rem 1rem;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

.footer p { margin: 0; }

.footer__identity {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

/* Long contact strings must wrap rather than push the footer sideways. */
.footer__contact a { color: var(--accent); overflow-wrap: anywhere; }
.footer__links { text-wrap: balance; }

.footer p { margin: 0; }

/* ---- home ----------------------------------------------------- */

.intro__lede {
  margin: 0 0 1.25rem;
  max-width: 34ch;
  font-size: 1.75rem;
  line-height: 1.32;
  letter-spacing: -0.012em;
}

.intro__byline {
  margin: 0 0 3.5rem;
  max-width: var(--measure);
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--ink-soft);
}

.intro__byline a {
  color: var(--accent);
  font-weight: 600;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

.entry {
  padding-block: 1.75rem;
  border-top: 1px solid var(--rule);
}

.entry__date {
  display: block;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 0.75rem;
  color: var(--ink-soft);
}

.entry__title {
  margin: 0.5rem 0 0.4rem;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 1.3125rem;
  font-weight: 600;
  line-height: 1.28;
  letter-spacing: -0.014em;
}

.entry__title a { color: var(--ink); text-decoration: none; }
.entry__title a:hover { color: var(--accent); }

.entry__blurb {
  margin: 0;
  max-width: var(--measure);
  color: var(--ink-soft);
  font-size: 0.9688rem;
}

/* ---- post head ------------------------------------------------ */

.post__head {
  padding-bottom: 2.25rem;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 2.75rem;
}

.post__head h1 {
  margin: 0;
  max-width: 24ch;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: clamp(2rem, 5.2vw, 2.875rem);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.026em;
}

.post__subtitle {
  margin: 1rem 0 0;
  max-width: 52ch;
  font-size: 1.125rem;
  color: var(--ink-soft);
}

.post__meta {
  margin: 1.5rem 0 0;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 0.75rem;
  color: var(--ink-soft);
}

.post__sep {
  display: inline-block;
  width: 1.5rem;
  height: 1px;
  margin: 0 0.5rem;
  vertical-align: middle;
  background: var(--rule);
}

/* ---- prose ---------------------------------------------------- */

.prose > * { max-width: var(--measure); }

.prose h2 {
  margin: 3.5rem 0 1rem;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 1.4375rem;
  font-weight: 600;
  line-height: 1.25;
  letter-spacing: -0.017em;
}

.prose h3 {
  margin: 2.5rem 0 0.75rem;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 1.125rem;
  font-weight: 600;
}

.prose p { margin: 0 0 1.25rem; }

.prose a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

.prose ul, .prose ol { margin: 0 0 1.5rem; padding-left: 1.35rem; }
.prose li { margin-bottom: 0.35rem; }

.prose strong { font-weight: 600; }

.prose hr {
  max-width: none;
  height: 1px;
  margin: 3rem 0;
  border: 0;
  background: var(--rule);
}

.prose blockquote {
  margin: 1.75rem 0;
  padding: 0.1rem 0 0.1rem 1.25rem;
  border-left: 2px solid var(--accent);
  font-size: 1.1875rem;
  line-height: 1.45;
}

.prose blockquote p:last-child { margin-bottom: 0; }

/* ---- code + diagrams break out of the text measure ------------ */

.prose pre,
.prose .mermaid,
.prose .highlighter-rouge {
  max-width: none;
}

.prose pre {
  margin: 1.75rem 0;
  padding: 1.1rem 1.25rem;
  overflow-x: auto;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 3px;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 0.8125rem;
  line-height: 1.55;
  tab-size: 2;
}

.prose code {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 0.875em;
}

.prose :not(pre) > code {
  padding: 0.12em 0.35em;
  background: var(--surface);
  border-radius: 2px;
}

.prose pre code { background: none; padding: 0; font-size: inherit; }

.prose .mermaid {
  margin: 2rem 0;
  padding: 1.25rem;
  overflow-x: auto;
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 3px;
  text-align: center;
}

.prose .mermaid svg { max-width: 100%; height: auto; }

.prose table {
  width: 100%;
  margin: 1.75rem 0;
  border-collapse: collapse;
  font-size: 0.9375rem;
}

.prose th, .prose td {
  padding: 0.6rem 0.75rem;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--rule);
}

.prose th {
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-weight: 600;
}

/* ---- callouts ------------------------------------------------- */

/* Blockquotes marked {: .callout} in the source: a labelled aside, visually
   distinct from a pull quote. The label text carries the type, so the styling
   does not have to rely on colour alone. */
.prose blockquote.callout {
  margin: 2rem 0;
  padding: 0.95rem 1.15rem;
  background: var(--surface);
  border-left: 3px solid var(--accent);
  border-radius: 0 3px 3px 0;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.9375rem;
  line-height: 1.6;
}

.prose blockquote.callout > p:first-child {
  margin-bottom: 0.35rem;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--accent);
}

.prose blockquote.callout > p:last-child { margin-bottom: 0; }

/* ---- figure captions ------------------------------------------ */

.prose .mermaid + p em,
.prose .mermaid + p > em:only-child {
  display: block;
  margin-top: -0.75rem;
  color: var(--ink-soft);
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.8125rem;
  font-style: normal;
  line-height: 1.5;
}

/* ---- wide tables scroll instead of crushing their columns ------ */

.prose table {
  display: block;
  max-width: 100%;
  overflow-x: auto;
}

.prose td, .prose th { min-width: 7rem; }
.prose td:first-child, .prose th:first-child { min-width: 6rem; }

/* ---- FAQ ------------------------------------------------------- */

.faq {
  max-width: var(--measure);
  margin-top: 3.5rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--rule);
}

.faq h2 {
  margin: 0 0 1.25rem;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 1.4375rem;
  font-weight: 600;
  letter-spacing: -0.017em;
}

.faq__item { border-bottom: 1px solid var(--rule); }

.faq__q {
  padding: 0.85rem 0;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

.faq__q::-webkit-details-marker { display: none; }

.faq__q::before {
  content: "+";
  display: inline-block;
  width: 1.1rem;
  color: var(--accent);
  font-weight: 500;
}

.faq__item[open] .faq__q::before { content: "\2212"; }

.faq__a {
  padding: 0 0 1rem 1.1rem;
  font-size: 1rem;
  line-height: 1.6;
}

.faq__a p { margin: 0; }

/* ---- author card ---------------------------------------------- */

.author-card {
  margin-top: 3.5rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--rule);
}

.author-card__label {
  margin: 0 0 1rem;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

/* The badge renders an iframe once LinkedIn's script loads; until then the
   fallback link shows. Cap the width so neither state can overflow a phone. */
.author-card .badge-base { max-width: 100%; }
.author-card iframe { max-width: 100% !important; border: 0; }

.author-card .LI-simple-link {
  color: var(--accent);
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.9375rem;
}

/* ---- tool strip ----------------------------------------------- */

/* Brand marks are drawn monochrome in the page's ink colour, which is how
   single-path glyph icons are meant to be used. Where no official mark was
   available, a plain two-letter monogram stands in — deliberately typographic
   so it reads as a placeholder rather than as someone's logo. */
.prose .tool-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  max-width: none;
  margin: 1.75rem 0;
  padding: 0;
}

.tool {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.75rem 0.4rem 0.5rem;
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 999px;
  font-family: "IBM Plex Sans", system-ui, sans-serif;
  font-size: 0.8125rem;
  color: var(--ink);
  white-space: nowrap;
}

.tool__mark {
  flex: none;
  width: 1.125rem;
  height: 1.125rem;
  fill: var(--ink);
}

.tool__mark--initial {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--ink-soft);
  border-radius: 50%;
  color: var(--ink-soft);
  font-size: 0.5625rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

/* ---- a11y ----------------------------------------------------- */

:where(a, button):focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 2px;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

@media (max-width: 40rem) {
  body { font-size: 1rem; }
  .masthead { padding-top: 2rem; padding-bottom: 2rem; }
  .intro__lede { font-size: 1.4375rem; }
  .prose h2 { margin-top: 2.75rem; font-size: 1.3125rem; }
  .prose pre { font-size: 0.75rem; }
  .prose .mermaid { padding: 0.75rem; }
  .prose table { font-size: 0.875rem; }
}