/* Flits — design system
   Black canvas, tight grotesque type, media cards, pill buttons.
   Ships in dark and light; the palette follows the device setting. */

/* ---------------------------------------------------------------- tokens */

/* Dark is the base palette. Every colour below is overridden in the
   prefers-color-scheme: light block — nothing else in this file hardcodes
   a black or a white. */

:root {
  --bg: #000000;
  --fg: #ffffff;
  --muted: #a5a5a5;
  --faint: #737373;
  --line: rgba(255, 255, 255, 0.14);
  --line-soft: rgba(255, 255, 255, 0.08);
  --surface: #0e0e0e;
  --surface-2: #171717;

  /* translucent header once scrolled */
  --header-bg: rgba(0, 0, 0, 0.72);
  /* soft hover wash on ghost buttons and nav pills */
  --hover-soft: rgba(255, 255, 255, 0.08);

  /* reversed pair — primary button, selection, skip link */
  --contrast-bg: #ffffff;
  --contrast-fg: #000000;
  --contrast-bg-hover: #d9d9d9;

  --prose-fg: #e6e6e6;
  --math-fg: #ededed;
  --footer-link: #d4d4d4;

  /* the wordmark PNG is white artwork; flip it on a light canvas */
  --logo-filter: none;

  --page: 1440px;
  --gutter: 20px;
  --nav-h: 64px;
  --radius: 10px;
  --radius-lg: 20px;

  --section-y: clamp(56px, 8vw, 104px);

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #ffffff;
    --fg: #000000;
    --muted: #5a5a5a;
    --faint: #6f6f6f;
    --line: rgba(0, 0, 0, 0.16);
    --line-soft: rgba(0, 0, 0, 0.09);
    --surface: #f7f7f7;
    --surface-2: #eeeeee;

    --header-bg: rgba(255, 255, 255, 0.72);
    --hover-soft: rgba(0, 0, 0, 0.06);

    --contrast-bg: #000000;
    --contrast-fg: #ffffff;
    --contrast-bg-hover: #2e2e2e;

    --prose-fg: #1c1c1c;
    --math-fg: #111111;
    --footer-link: #3a3a3a;

    --logo-filter: invert(1);
  }
}

@media (min-width: 768px) {
  :root { --gutter: 32px; --nav-h: 68px; }
}

@media (min-width: 1280px) {
  :root { --gutter: 48px; }
}

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

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

* { margin: 0; padding: 0; }

html {
  background: var(--bg);
  color-scheme: light dark;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}

body {
  background: var(--bg);
  color: var(--fg);
  font-family: "Inter", ui-sans-serif, -apple-system, BlinkMacSystemFont,
    "Segoe UI", Helvetica, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  font-weight: 400;
  line-height: 1.5;
  font-feature-settings: "cv05" 1, "cv08" 1, "ss03" 1;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

a { color: inherit; }

ul, ol { list-style: none; }

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

::selection { background: var(--contrast-bg); color: var(--contrast-fg); }

:focus-visible {
  outline: 2px solid var(--fg);
  outline-offset: 3px;
  border-radius: 4px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: 8px;
  left: 8px;
  z-index: 200;
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--contrast-bg);
  color: var(--contrast-fg);
  transform: translateY(-200%);
}

.skip-link:focus { transform: none; }

/* ---------------------------------------------------------------- layout */

.wrap {
  width: 100%;
  max-width: var(--page);
  margin: 0 auto;
  padding-inline: var(--gutter);
}

.section { padding-block: var(--section-y); }

/* anchors clear the sticky bar */
[id] { scroll-margin-top: calc(var(--nav-h) + 20px); }

.section--tight { padding-block: clamp(40px, 5vw, 72px); }

.rule {
  border: 0;
  border-top: 1px solid var(--line-soft);
}

/* ---------------------------------------------------------------- type */

h1, h2, h3, h4 {
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1.1;
  text-wrap: balance;
}

.display {
  font-size: clamp(2.125rem, 7.6vw, 4.25rem);
  line-height: 1.06;
  letter-spacing: -0.03em;
}

.h1 {
  font-size: clamp(1.875rem, 6.6vw, 3.25rem);
  line-height: 1.07;
  letter-spacing: -0.03em;
}

.h2 {
  font-size: clamp(1.1875rem, 4.4vw, 1.75rem);
  font-weight: 400;
  line-height: 1.15;
  letter-spacing: -0.025em;
}

.h3 {
  font-size: clamp(1.0625rem, 1.8vw, 1.1875rem);
  letter-spacing: -0.022em;
}

.lede {
  font-size: clamp(1rem, 3.7vw, 1.125rem);
  line-height: 1.5;
  letter-spacing: -0.011em;
  color: var(--muted);
  text-wrap: pretty;
}

.eyebrow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  font-size: clamp(0.875rem, 3.2vw, 0.9375rem);
  letter-spacing: -0.005em;
  color: var(--faint);
}

.eyebrow strong {
  font-weight: 400;
  color: var(--fg);
}

.center { text-align: center; }

.center .eyebrow { justify-content: center; }

.stack > * + * { margin-top: var(--stack, 24px); }

/* ---------------------------------------------------------------- header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: transparent;
  transition: background 0.25s var(--ease), backdrop-filter 0.25s var(--ease);
}

.site-header.is-stuck {
  background: var(--header-bg);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: var(--nav-h);
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: clamp(1.0625rem, 4vw, 1.1875rem);
  font-weight: 700;
  letter-spacing: -0.032em;
  text-decoration: none;
}

.wordmark img {
  width: auto;
  height: 1.05em;
  filter: var(--logo-filter);
}

.nav-links {
  display: none;
  align-items: center;
  gap: 4px;
}

.nav-links a {
  padding: 8px 12px;
  border-radius: 999px;
  font-size: 0.9375rem;
  letter-spacing: -0.008em;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.18s var(--ease), background 0.18s var(--ease);
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--fg);
  background: var(--hover-soft);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-right: -10px;
}

.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 999px;
  color: var(--fg);
  transition: opacity 0.18s var(--ease), background 0.18s var(--ease);
}

.icon-btn:hover { opacity: 0.65; }

.icon-btn svg {
  width: 21px;
  height: 21px;
  stroke: currentColor;
}

@media (min-width: 900px) {
  .nav-links { display: flex; }
}

/* ---- slide-over menu ---- */

.menu {
  position: fixed;
  inset: 0;
  z-index: 150;
  display: grid;
  grid-template-rows: var(--nav-h) 1fr;
  background: var(--bg);
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.22s var(--ease), visibility 0.22s var(--ease);
}

.menu[data-open="true"] {
  visibility: visible;
  opacity: 1;
}

/* The panel fades in over a page of the same colour, so on its own the fade
   is invisible and opening reads as an instant jump. The groups carry the
   motion instead: they rise and settle in sequence, which is the part the eye
   actually registers. The delays apply only while opening, so closing
   collapses at once rather than unwinding. */

.menu__group {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease);
}

.menu[data-open="true"] .menu__group {
  opacity: 1;
  transform: none;
}

.menu[data-open="true"] .menu__group:nth-child(1) { transition-delay: 0.05s; }
.menu[data-open="true"] .menu__group:nth-child(2) { transition-delay: 0.1s; }
.menu[data-open="true"] .menu__group:nth-child(3) { transition-delay: 0.15s; }
.menu[data-open="true"] .menu__group:nth-child(4) { transition-delay: 0.2s; }

@media (prefers-reduced-motion: reduce) {
  .menu__group { opacity: 1; transform: none; }
  .menu[data-open="true"] .menu__group { transition-delay: 0s; }
}

.menu__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: var(--page);
  margin: 0 auto;
  padding-inline: var(--gutter);
}

.menu__body {
  overflow-y: auto;
  padding: 24px var(--gutter) 64px;
  width: 100%;
  max-width: var(--page);
  margin: 0 auto;
}

.menu__group + .menu__group {
  margin-top: 32px;
  padding-top: 32px;
  border-top: 1px solid var(--line-soft);
}

.menu__label {
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--faint);
  margin-bottom: 12px;
}

.menu__body a {
  display: block;
  padding: 9px 0;
  font-size: 1.1875rem;
  font-weight: 500;
  letter-spacing: -0.026em;
  text-decoration: none;
}

.menu__body a:hover { color: var(--muted); }

body.is-locked { overflow: hidden; }

/* ---- search overlay ---- */

.search {
  position: fixed;
  inset: 0;
  z-index: 160;
  background: var(--bg);
  display: grid;
  grid-template-rows: auto 1fr;
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.18s var(--ease), visibility 0.18s var(--ease);
}

.search[data-open="true"] {
  visibility: visible;
  opacity: 1;
}

.search__bar {
  display: flex;
  align-items: center;
  gap: 12px;
  height: var(--nav-h);
  border-bottom: 1px solid var(--line-soft);
}

.search__bar svg {
  flex: none;
  width: 22px;
  height: 22px;
  stroke: var(--muted);
}

.search__bar input {
  flex: 1;
  min-width: 0;
  height: 100%;
  border: 0;
  background: none;
  color: var(--fg);
  font: inherit;
  font-size: 1rem;
  letter-spacing: -0.01em;
  outline: none;
}

.search__bar input::placeholder { color: var(--faint); }

.search__results {
  overflow-y: auto;
  padding: 12px var(--gutter) 64px;
}

.search__results a {
  display: block;
  padding: 18px 0;
  border-bottom: 1px solid var(--line-soft);
  text-decoration: none;
}

.search__results a:hover { opacity: 0.7; }

.search__results h2 {
  font-size: 1rem;
  font-weight: 400;
  letter-spacing: -0.018em;
}

.search__results p {
  margin-top: 4px;
  font-size: 0.9375rem;
  color: var(--faint);
}

.search__empty {
  padding: 24px 0;
  color: var(--faint);
}

/* ---------------------------------------------------------------- buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 22px;
  border-radius: 999px;
  font-size: clamp(0.875rem, 3.3vw, 0.9375rem);
  font-weight: 500;
  letter-spacing: -0.012em;
  text-decoration: none;
  white-space: nowrap;
  transition: background 0.18s var(--ease), color 0.18s var(--ease),
    border-color 0.18s var(--ease), transform 0.18s var(--ease);
}

.btn:active { transform: scale(0.985); }

.btn--primary {
  background: var(--contrast-bg);
  color: var(--contrast-fg);
}

.btn--primary:hover { background: var(--contrast-bg-hover); }

.btn--ghost {
  border: 1px solid var(--line);
  color: var(--fg);
}

.btn--ghost:hover {
  background: var(--hover-soft);
  border-color: transparent;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.hero .btn-row { flex-wrap: nowrap; }

@media (max-width: 420px) {
  .hero .btn { padding: 0 18px; }
}

.center .btn-row { justify-content: center; }

/* ---------------------------------------------------------------- section head */

.section-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: clamp(24px, 3vw, 40px);
}

.view-all {
  flex: none;
  align-self: center;
  font-size: 0.875rem;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--faint);
  text-decoration: none;
  transition: color 0.18s var(--ease);
}

.view-all:hover { color: var(--muted); }

/* ---------------------------------------------------------------- rails & grids */

.rail {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: 72%;
  gap: 16px;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  scroll-snap-type: x mandatory;
  scroll-padding-inline: var(--gutter);
  padding-inline: var(--gutter);
  margin-inline: calc(-1 * var(--gutter));
  scrollbar-width: none;
}

.rail::-webkit-scrollbar { display: none; }

.rail > * { scroll-snap-align: start; }

@media (min-width: 600px) {
  .rail { grid-auto-columns: 46%; }
}

@media (min-width: 1024px) {
  .rail {
    grid-auto-flow: row;
    grid-template-columns: repeat(var(--cols, 3), minmax(0, 1fr));
    gap: 24px 24px;
    overflow: visible;
    padding-inline: 0;
    margin-inline: 0;
  }
}

.grid {
  display: grid;
  gap: 24px;
}

@media (min-width: 700px) {
  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 560px) {
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 900px) {
  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

/* ---------------------------------------------------------------- cards */

.card {
  display: flex;
  flex-direction: column;
  gap: 16px;
  color: inherit;
  text-decoration: none;
}

.card__media {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  aspect-ratio: 1 / 1;
  background: var(--surface-2);
}

.card__media--wide { aspect-ratio: 16 / 10; }

.card__media > * {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s var(--ease);
}

.card:hover .card__media > * { transform: scale(1.03); }

.card__title {
  font-size: clamp(1.0625rem, 4.2vw, 1.1875rem);
  font-weight: 400;
  line-height: 1.22;
  letter-spacing: -0.02em;
  text-wrap: pretty;
}

.card:hover .card__title { color: var(--muted); }

.card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  margin-top: auto;
  padding-top: 4px;
  font-size: clamp(0.8125rem, 3.1vw, 0.875rem);
  letter-spacing: -0.005em;
  color: var(--faint);
}

.card__meta span:first-child { color: var(--fg); }

.card__body {
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex: 1;
}

/* ---- panel card (text only, bordered) ---- */

.panel {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px 20px 24px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
  background: var(--surface);
  color: inherit;
  text-decoration: none;
  transition: background 0.2s var(--ease), border-color 0.2s var(--ease);
}

a.panel:hover {
  background: var(--surface-2);
  border-color: var(--line);
}

.panel__index {
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--faint);
}

.panel p {
  font-size: 0.9375rem;
  line-height: 1.45;
  color: var(--muted);
  letter-spacing: -0.008em;
  text-wrap: pretty;
}

/* ---------------------------------------------------------------- hero */

.hero {
  padding-top: clamp(48px, 9vw, 108px);
  padding-bottom: clamp(40px, 6vw, 72px);
}

.hero__inner {
  max-width: 920px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(20px, 3vw, 32px);
}

.hero .lede { max-width: 640px; }

.page-hero {
  padding-top: clamp(40px, 7vw, 88px);
  padding-bottom: clamp(28px, 4vw, 48px);
}

.page-hero__inner {
  max-width: 860px;
  margin-inline: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: clamp(16px, 2.4vw, 24px);
}

.page-hero .eyebrow { justify-content: center; }

.page-hero .lede { max-width: 680px; }

/* ---------------------------------------------------------------- gradient art */

.art {
  position: absolute;
  inset: 0;
  border-radius: inherit;
}

.art--1 {
  background:
    radial-gradient(120% 90% at 18% 12%, #7fe4ff 0%, rgba(127, 228, 255, 0) 58%),
    radial-gradient(100% 100% at 82% 26%, #ffffff 0%, rgba(255, 255, 255, 0) 46%),
    linear-gradient(148deg, #34c6f4 0%, #1f5fe0 46%, #0b2f8f 100%);
}

.art--2 {
  background:
    radial-gradient(90% 80% at 78% 18%, #ffd977 0%, rgba(255, 217, 119, 0) 60%),
    radial-gradient(80% 80% at 12% 84%, #ff8a5c 0%, rgba(255, 138, 92, 0) 62%),
    linear-gradient(160deg, #f7b733 0%, #e2573c 58%, #7a1f3d 100%);
}

.art--3 {
  background:
    radial-gradient(100% 90% at 24% 78%, #b6a6ff 0%, rgba(182, 166, 255, 0) 60%),
    radial-gradient(80% 70% at 80% 20%, #ffffff 0%, rgba(255, 255, 255, 0) 52%),
    linear-gradient(140deg, #6f5cf0 0%, #3a2ca8 52%, #140f3a 100%);
}

.art--4 {
  background:
    radial-gradient(90% 90% at 20% 22%, #9ff5d2 0%, rgba(159, 245, 210, 0) 58%),
    radial-gradient(90% 80% at 84% 82%, #1f8f7a 0%, rgba(31, 143, 122, 0) 62%),
    linear-gradient(152deg, #3fd6a8 0%, #12806f 54%, #05302f 100%);
}

.art--5 {
  background:
    radial-gradient(100% 80% at 76% 24%, #ffb4c8 0%, rgba(255, 180, 200, 0) 58%),
    radial-gradient(80% 80% at 16% 80%, #6b4bff 0%, rgba(107, 75, 255, 0) 60%),
    linear-gradient(146deg, #ff7ea8 0%, #b0399b 52%, #2b1358 100%);
}

.art--6 {
  background:
    radial-gradient(110% 90% at 30% 20%, #e9e9e9 0%, rgba(233, 233, 233, 0) 56%),
    radial-gradient(90% 80% at 84% 78%, #4a4a4a 0%, rgba(74, 74, 74, 0) 60%),
    linear-gradient(150deg, #c9c9c9 0%, #6c6c6c 50%, #121212 100%);
}

.art--grain::after {
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0.16;
  background-image: radial-gradient(rgba(255, 255, 255, 0.45) 0.5px, transparent 0.6px);
  background-size: 4px 4px;
}

.banner {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  aspect-ratio: 16 / 9;
}

@media (min-width: 900px) {
  .banner { aspect-ratio: 21 / 8; }
}

/* ---------------------------------------------------------------- feature split */

.feature {
  display: grid;
  gap: clamp(24px, 4vw, 56px);
  align-items: center;
}

@media (min-width: 900px) {
  .feature { grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); }
  .feature--flip .feature__media { order: 2; }
}

.feature__media {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  aspect-ratio: 4 / 5;
  max-height: 560px;
}

.feature__media img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 22%;
}

.feature__body {
  display: flex;
  flex-direction: column;
  gap: 20px;
  align-items: flex-start;
}

/* ---------------------------------------------------------------- spec list */

.specs {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line-soft);
}

.specs > div {
  display: grid;
  gap: 4px 32px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line-soft);
}

@media (min-width: 700px) {
  .specs > div { grid-template-columns: minmax(0, 180px) minmax(0, 1fr); }
}

.specs dt {
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--faint);
  padding-top: 2px;
}

.specs dd {
  font-size: 0.9375rem;
  letter-spacing: -0.01em;
}

.specs dd a { text-decoration: none; border-bottom: 1px solid var(--line); }

.specs dd a:hover { color: var(--muted); }

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

.prose {
  max-width: 44rem;
  margin-inline: auto;
  font-size: 1rem;
  line-height: 1.65;
  letter-spacing: -0.011em;
  color: var(--prose-fg);
}

@media (min-width: 768px) {
  .prose { font-size: 1.0625rem; }
}

.prose > * + * { margin-top: 1.35em; }

.prose + .prose { margin-top: clamp(40px, 5vw, 64px); }

.prose p { text-wrap: pretty; }

.prose h2 {
  font-size: clamp(1.1875rem, 2.2vw, 1.375rem);
  letter-spacing: -0.026em;
  color: var(--fg);
  margin-top: 2.2em;
  margin-bottom: 0.1em;
}

.prose h3 {
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: -0.018em;
  color: var(--fg);
  margin-top: 1.9em;
  margin-bottom: -0.35em;
}

.prose h2:first-child,
.prose h3:first-child { margin-top: 0; }

.prose em { font-style: italic; }

.prose strong { font-weight: 600; color: var(--fg); }

.prose a {
  color: var(--fg);
  text-decoration: underline;
  text-decoration-color: var(--line);
  text-underline-offset: 0.22em;
}

.prose a:hover { text-decoration-color: currentColor; }

.prose .kv {
  font-size: 0.9375rem;
  letter-spacing: 0.02em;
  color: var(--muted);
  margin-top: 0.35em;
}

.prose .li {
  position: relative;
  padding-left: 1.1em;
  margin-top: 0.5em;
  color: var(--prose-fg);
}

.prose .li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 5px;
  height: 1px;
  background: var(--faint);
}

.prose br { display: none; }

.prose pre.code,
pre.code {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--muted);
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 20px 22px;
  overflow-x: auto;
}

.prose figure { margin-top: 2.2em; }

.prose figure img {
  width: 100%;
  border-radius: var(--radius);
}

.prose figcaption {
  margin-top: 12px;
  font-size: 0.9375rem;
  color: var(--faint);
}

/* ---------------------------------------------------------------- article */

.article-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 24px;
  padding-bottom: clamp(24px, 3vw, 40px);
  font-size: 0.875rem;
  color: var(--faint);
}

.article-meta span:first-child { color: var(--fg); }

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9375rem;
  color: var(--muted);
  text-decoration: none;
}

.back-link:hover { color: var(--fg); }

.back-link svg { width: 14px; height: 14px; }

/* ---------------------------------------------------------------- footer */

.site-footer {
  border-top: 1px solid var(--line-soft);
  padding-block: clamp(40px, 5vw, 72px) 40px;
}

.footer-grid {
  display: grid;
  gap: 36px 24px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

@media (min-width: 900px) {
  .footer-grid { grid-template-columns: minmax(0, 1.4fr) repeat(3, minmax(0, 1fr)); }
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 12px;
  grid-column: 1 / -1;
}

@media (min-width: 900px) {
  .footer-brand { grid-column: auto; }
}

.footer-brand p {
  max-width: 30ch;
  font-size: 0.9375rem;
  color: var(--faint);
  letter-spacing: -0.005em;
}

.footer-col h2 {
  font-size: 0.8125rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--faint);
  margin-bottom: 14px;
}

.footer-col li + li { margin-top: 10px; }

.footer-col a {
  font-size: 0.9375rem;
  letter-spacing: -0.008em;
  color: var(--footer-link);
  text-decoration: none;
}

.footer-col a:hover { color: var(--fg); }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  align-items: center;
  margin-top: clamp(40px, 5vw, 64px);
  padding-top: 24px;
  border-top: 1px solid var(--line-soft);
  font-size: 0.875rem;
  color: var(--faint);
}

.footer-bottom a { text-decoration: none; }

.footer-bottom a:hover { color: var(--fg); }

.footer-bottom .spacer { margin-left: auto; }

@media (max-width: 640px) {
  .footer-bottom .spacer { margin-left: 0; }
}

/* ---------------------------------------------------------------- motion */

@view-transition { navigation: auto; }

@keyframes page-in {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: none; }
}

main { animation: page-in 0.36s var(--ease) both; }

::view-transition-old(root) {
  animation: fade-out 0.16s ease both;
}

::view-transition-new(root) {
  animation: page-in 0.28s var(--ease) both;
}

@keyframes fade-out {
  to { opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  main { animation: none; }
  @view-transition { navigation: none; }
}

/* ---------------------------------------------------------------- math */

.math {
  margin-top: 1.8em;
  /* Wide formulas scroll sideways. overflow-y has to be stated explicitly:
     leaving it visible makes it compute to auto next to an auto overflow-x,
     which let these boxes scroll a few stray pixels vertically off KaTeX's
     strut heights. */
  overflow-x: auto;
  overflow-y: hidden;
  overscroll-behavior-inline: contain;
  scrollbar-width: none;
}

.math::-webkit-scrollbar { display: none; }

.math .katex-display {
  margin: 0;
  /* KaTeX renders a little outside this box, so the padding has to sit on it
     rather than on .math: padding on the scroll container itself grows the
     scroll height with the client height and absorbs nothing. */
  padding-block: 8px;
}

.katex { color: var(--math-fg); }

.prose .math + p { margin-top: 1.6em; }

.prose .math-note {
  margin-top: 0.9em;
  font-size: 0.875rem;
  color: var(--faint);
}