/* ==========================================================================
   MINIMALISSIMO-INSPIRED THEME
   White canvas, Geist Sans, single orange accent, editorial grid,
   breadcrumb header, author sidebar, floating pill + pop-up menu.
   ========================================================================== */

:root {
  --bg: #ffffff;
  --fg: #141414;
  --muted: #8a8a8a;
  --muted-2: #b3b3b3;
  --line: #ececec;
  --line-strong: #e0e0e0;
  --tile: #f2f2f2;
  --tile-hover: #ededed;
  --footer-bg: #f7f7f7;
  --accent: AccentColor; /* the viewer's OS/device accent colour */

  --sans: "Geist Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;

  --maxw: 125rem; /* ~2000px, matching minimalissimo */
  --readw: 40rem;
  --pad: 1.5rem;
  --gap: 1.5rem;
  --aside: 220px;
  --dur: 0.18s;

  /* Shared fluid text size for the wordmark, home intro, and blog body.
     Equals 24px at ~1440px, scales with the viewport. */
  --fs-text: clamp(1.35rem, 0.96rem + 0.6vw, 1.8rem);
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  letter-spacing: -0.005em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
::selection { background: var(--accent); color: #fff; }

/* --------------------------------------------------------------------------
   Header — breadcrumb (page directory) + date
   -------------------------------------------------------------------------- */

.site-header {
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  padding: 1rem var(--pad) 0;
  font-size: 1rem; /* 16px */
  font-weight: 400;
}

.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.5rem;
}
.crumbs a { color: #555; }
.crumbs a:hover { background-size: 100% 100%; color: #fff; }
.crumbs__sep { color: var(--muted-2); }
.crumbs a.crumbs__current { color: #000; }
.crumbs a.crumbs__current:hover { color: #fff; }
.crumbs__date { color: var(--muted); white-space: nowrap; }

/* --------------------------------------------------------------------------
   Content container
   -------------------------------------------------------------------------- */

.container {
  display: block;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 1rem var(--pad) 0;
}

/* --------------------------------------------------------------------------
   Homepage author band (horizontal, after the intro)
   -------------------------------------------------------------------------- */

.about-band {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1.25rem 0;
  margin: 0 0 2.5rem;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.about-band__avatar {
  width: 76px;
  height: 76px;
  object-fit: cover;
  border-radius: 3px;
  flex: none;
}
.about-band__body { flex: 1 1 auto; min-width: 0; }
.about-band__name { font-size: 1rem; font-weight: 700; }
.about-band__pron { font-weight: 400; color: var(--muted); margin-left: 0.4rem; }
.about-band__bio { color: var(--muted); font-size: 0.9rem; margin-top: 0.2rem; }
.about-band__facts { color: var(--muted); font-size: 0.85rem; margin-top: 0.35rem; display: flex; flex-wrap: wrap; gap: 0.35rem 1rem; }
.about-band__links { flex: none; display: flex; flex-wrap: wrap; gap: 1.25rem; font-size: 0.9rem; }
.about-band__links a:hover { background-size: 100% 100%; color: #fff; }

/* --------------------------------------------------------------------------
   Document layout (minimalissimo article/home): media left, content right
   -------------------------------------------------------------------------- */

.doc {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem; /* 16px gutter, matching minimalissimo */
  margin: 0 0 4rem;
  align-items: start;
}
.doc__media { min-width: 0; }
.doc__media img { width: 100%; }
.doc__main { min-width: 0; }

.doc__title {
  font-size: 1.5rem; /* 24px */
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 600;
  margin: 0 0 0.75rem;
}

.doc__facts { margin-top: 2rem; }

/* --------------------------------------------------------------------------
   Home hero: wordmark in the left rail, top-aligned with the intro, which
   sits where minimalissimo's cards begin (~26%).
   -------------------------------------------------------------------------- */

.container--home { padding-top: 1rem; }

/* Same 3-column grid as the Writings cards, so the intro's left edge lines
   up with where the second card would start. */
.home-hero {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  column-gap: var(--gap);
  align-items: start;
  margin: 0 0 2.5rem;
}
.home-hero__brand {
  grid-column: 1;
  justify-self: start; /* hug the text so the hover wipe covers only "khnguyxn" */
  font-size: 1rem; /* 16px */
  font-weight: 400;
  color: #000;
}
.home-hero__brand:hover { background-size: 100% 100%; color: #fff; }

.home-intro {
  grid-column: 2 / 4;
  font-size: 1.5rem; /* 24px */
  line-height: 1.4;
  text-align: right;
}
.home-intro p { margin: 0 0 0.6rem; }
.home-intro p:last-child { margin-bottom: 0; }
.home-intro a { text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 3px; }
.home-intro a:hover { background-size: 100% 100%; color: #fff; }

.home-writing__label,
.listing__label {
  font-size: 0.8rem;
  margin-bottom: 1rem;
}
.home-writing__label { color: #000; }
.listing__label { color: var(--muted); }

/* --------------------------------------------------------------------------
   Card grid (posts)
   -------------------------------------------------------------------------- */

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2.75rem var(--gap);
}
.card { min-width: 0; }
.card a { display: block; }

.card__tile {
  position: relative;
  aspect-ratio: 4 / 3;
  background: var(--tile);
  padding: 1.4rem 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: filter var(--dur) ease;
  overflow: hidden;
}
.card:hover .card__tile { filter: brightness(0.94); }

/* Le Corbusier primaries — red / yellow / blue / green, assigned by script so
   no two adjacent cards share a colour. */
.card--red .card__tile    { background: #c0392b; color: #fff; }
.card--blue .card__tile   { background: #2c4c8c; color: #fff; }
.card--green .card__tile  { background: #3a7d44; color: #fff; }
.card--yellow .card__tile { background: #edb100; color: #141414; }
.card--red .card__kicker,
.card--blue .card__kicker,
.card--green .card__kicker { color: rgba(255, 255, 255, 0.72); }
.card--yellow .card__kicker { color: rgba(0, 0, 0, 0.55); }
.card--red .card__head,
.card--blue .card__head,
.card--green .card__head,
.card--yellow .card__head { color: inherit; }

.card__kicker { font-size: 0.75rem; color: var(--muted); font-family: var(--mono); letter-spacing: 0.02em; }
.card__head { font-size: 1.5rem; line-height: 1.15; letter-spacing: -0.02em; font-weight: 400; max-width: 20ch; }
/* the highlight hugs the title text per line (inline + clone), not the block box */
.card__head-hl { -webkit-box-decoration-break: clone; box-decoration-break: clone; }
.card__meta { margin-top: 0.75rem; font-size: 0.85rem; color: var(--muted); }
.card:hover .card__head-hl { background-size: 100% 100%; color: #fff; }

/* --------------------------------------------------------------------------
   Article / page
   -------------------------------------------------------------------------- */

.article--wide { max-width: 64rem; margin: 0.5rem auto 4rem; text-align: center; }

/* Image-less posts: a centered reading column */
.article-center { max-width: 42rem; margin: 0 auto 4rem; }

.fact {
  display: flex;
  gap: 0.75rem;
  padding: 0.5rem 0;
  border-top: 1px solid var(--line);
  font-size: 0.85rem;
}
.fact:last-child { border-bottom: 1px solid var(--line); }
.fact__k { color: var(--muted); flex: none; min-width: 5rem; }
.fact__v { color: var(--fg); }

.article__body { min-width: 0; font-size: 1rem; line-height: 1.4; }
.article__body mjx-container[display] { overflow-x: auto; overflow-y: hidden; }
.article__body > *:first-child { margin-top: 0; }
.article__body p { margin: 0 0 0.8rem; }
.article__body h1, .article__body h2, .article__body h3, .article__body h4 {
  font-weight: 500; letter-spacing: -0.02em; line-height: 1.2; margin: 1.5rem 0 0.4rem;
}
.article__body h2 { font-size: 1.4rem; }
.article__body h3 { font-size: 1.15rem; }
.article__body a { color: var(--accent); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2px; }
.article__body a:hover { background-size: 100% 100%; color: #fff; }
.article__body ul, .article__body ol { padding-left: 1.25rem; margin: 0 0 0.8rem; }
.article__body li { margin: 0.15rem 0; }
/* Ordered-list numbers: baseline-aligned via a counter so tall superscript
   math (e.g. a^{M'}) doesn't push the numbers above the math baseline. */
.article__body ol { list-style: none; counter-reset: olcount; padding-left: 0.5rem; }
.article__body ol > li { counter-increment: olcount; }
.article__body ol > li::before { content: counter(olcount) ".\00a0\00a0"; }
.article__body blockquote { margin: 1rem 0; padding-left: 1.25rem; border-left: 2px solid var(--accent); color: var(--muted); }
.article__body hr { border: 0; border-top: 1px solid var(--line); margin: 1.5rem 0; }
.article__body img { margin: 1.2rem auto; }
.article__body code { font-family: var(--mono); font-size: 0.9em; background: var(--tile); padding: 0.1em 0.35em; }
.article__body pre { background: var(--tile); padding: 1.1rem 1.25rem; overflow-x: auto; font-size: 0.9rem; line-height: 1.5; margin: 0 0 1.4rem; }
.article__body pre code { background: none; padding: 0; }

.pdf-embed { width: 100%; height: 85vh; border: 1px solid var(--line); }

/* Comments (giscus) */
.comments { margin-top: 5rem; padding-top: 1.5rem; border-top: 1px solid var(--line); }
.comments__title { font-size: 1.15rem; font-weight: 500; letter-spacing: -0.02em; margin: 0 0 1rem; }

/* MathJax: reset the inherited body line-height so it doesn't skew the
   baseline; let MathJax handle inline alignment natively. */
mjx-container { line-height: normal; }

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

.wordmark { font-size: 1rem; font-weight: 500; letter-spacing: 0.01em; }

.site-footer { background: var(--footer-bg); margin-top: 2.5rem; padding: 4rem 0 6rem; font-size: 0.85rem; }
.site-footer__inner {
  max-width: var(--maxw); margin: 0 auto; padding: 0 var(--pad);
  display: grid; grid-template-columns: repeat(12, 1fr); gap: 2rem var(--gap);
}
.footer-brand { grid-column: 1 / 4; }
.footer-brand p { color: var(--muted); margin: 0.75rem 0 0; max-width: 22ch; }
.footer-col { grid-column: span 2; }
.footer-col h3 { font-size: 0.75rem; font-weight: 500; color: var(--muted); text-transform: uppercase; letter-spacing: 0.08em; margin: 0 0 0.9rem; }
.footer-col ul { list-style: none; margin: 0; padding: 0; }
.footer-col li { margin: 0.4rem 0; }
.footer-col a:hover { background-size: 100% 100%; color: #fff; }
.footer-legal {
  grid-column: 1 / 13; margin-top: 2rem; padding-top: 1.5rem;
  border-top: 1px solid var(--line-strong); color: var(--muted);
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.5rem;
}

/* --------------------------------------------------------------------------
   Floating pill + pop-up menu
   -------------------------------------------------------------------------- */

.dock {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 1.5rem;
  margin: 0 auto;
  width: min(440px, calc(100% - 2rem));
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 0.5rem;
  background: #fff;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
  z-index: 50;
}
.dock__side {
  width: 2.5rem; height: 2.5rem;
  display: flex; align-items: center; justify-content: center;
  color: var(--fg); cursor: pointer; border-radius: 6px;
}
.dock__side:hover { color: #fff; }
.dock__side:hover svg { background-size: 100% 100%; }
.dock__side svg { width: 1.15rem; height: 1.15rem; }
.dock__brand { font-size: 0.95rem; font-weight: 500; letter-spacing: 0.01em; }
.dock__brand:hover { background-size: 100% 100%; color: #fff; }

.dock__toggle .ic-close { display: none; }
#nav-toggle:checked ~ .dock .dock__toggle .ic-open { display: none; }
#nav-toggle:checked ~ .dock .dock__toggle .ic-close { display: block; }

.menu-pop {
  position: fixed;
  left: 0;
  right: 0;
  margin: 0 auto;
  bottom: calc(1.5rem + 52px + 0.5rem);
  width: min(440px, calc(100% - 2rem));
  background: #fff;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  box-shadow: 0 10px 34px rgba(0, 0, 0, 0.10);
  padding: 0.5rem;
  z-index: 49;
  display: flex;
  flex-direction: column;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity var(--dur) ease, transform var(--dur) ease, visibility var(--dur) ease;
}
#nav-toggle:checked ~ .menu-pop { opacity: 1; visibility: visible; transform: translateY(0); }

.menu-pop a {
  display: block;
  padding: 0.5rem 0.75rem;
  font-size: 0.95rem;
  color: var(--fg);
  border-radius: 5px;
}
.menu-pop a:hover .menu-pop__hl { background-size: 100% 100%; color: #fff; }
.menu-pop__rule { height: 1px; background: var(--line); margin: 0.4rem 0.75rem; }

/* --------------------------------------------------------------------------
   Input reset
   -------------------------------------------------------------------------- */

#nav-toggle { position: absolute; opacity: 0; pointer-events: none; }

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

@media (max-width: 1100px) {
  .cards { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 820px) {
  .doc { grid-template-columns: 1fr; gap: 1.75rem; }
  .doc__media:empty { display: none; }
  .home-hero { grid-template-columns: 1fr; gap: 0.75rem; }
  .home-hero__brand, .home-intro { grid-column: 1; }
  .about-band { flex-wrap: wrap; }
  .about-band__links { flex-basis: 100%; }
  .footer-brand { grid-column: 1 / 7; }
  .footer-col { grid-column: span 3; }
}

@media (max-width: 640px) {
  :root { --pad: 1.1rem; }
  .cards { grid-template-columns: 1fr; }
  .about-band__avatar { width: 60px; height: 60px; }
  .footer-brand, .footer-col { grid-column: 1 / 13; }
  .dock, .menu-pop { width: calc(100% - 2rem); }
  .crumbs__date { display: none; }
}

/* --------------------------------------------------------------------------
   Hover affordance — a solid-black highlight wipes in from the left and the
   text flips to white (replaces the former orange-accent hover site-wide).
   -------------------------------------------------------------------------- */

.crumbs a,
.about-band__links a,
.home-intro a,
.home-hero__brand,
.footer-col a,
.dock__side svg,
.dock__brand,
.menu-pop__hl,
.article__body a,
.card__head-hl {
  background-image: linear-gradient(#000, #000);
  background-repeat: no-repeat;
  background-position: left center;
  background-size: 0% 100%;
  transition: background-size 0.3s ease, color 0.3s ease;
}

/* Inline prose/nav links get a little breathing room so the wipe reads as a
   marker highlight; the negative margin keeps their layout position unchanged. */
.crumbs a,
.about-band__links a,
.home-intro a,
.footer-col a,
.article__body a {
  padding: 0 0.14em;
  margin: 0 -0.14em;
  -webkit-box-decoration-break: clone;
  box-decoration-break: clone;
}