/* ===========================================================================
   mindstorms.site — stylesheet
   A single, dependency-free stylesheet. Dark by default, light "paper" theme,
   system fonts, no external requests.
   =========================================================================== */

/* ----- Theme tokens ------------------------------------------------------ */
:root {
  --accent: #ff6b3d;
  --accent-2: #ffb85c;

  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial,
    "Apple Color Emoji", "Segoe UI Emoji", sans-serif;
  --font-serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia,
    "Times New Roman", serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "Source Code Pro",
    Menlo, Consolas, "Liberation Mono", monospace;

  --wrap: 72rem;
  --reading: 42rem;
  --radius: 14px;
  --radius-sm: 9px;
  --gap: clamp(1rem, 3vw, 2rem);

  --shadow: 0 1px 2px rgba(0, 0, 0, 0.18), 0 8px 28px -12px rgba(0, 0, 0, 0.4);
  --transition: 160ms ease;
}

/* Dark theme (default) */
:root,
html[data-theme="dark"] {
  --bg: #0b0e14;
  --bg-alt: #0f131d;
  --surface: #151a26;
  --surface-2: #1b2230;
  --border: #232c3e;
  --border-soft: #1a2130;
  --text: #e7eaf2;
  --text-dim: #aeb6c8;
  --text-mute: #7f8aa1;
  --link: #ff8a5f;
  --link-hover: #ffa982;
  --code-bg: #0a0e18;
  --code-text: #e2e6f0;
  --selection: rgba(255, 107, 61, 0.3);
  --on-accent: #160a04;
}

/* Light "paper" theme */
html[data-theme="light"] {
  --bg: #f6f3ec;
  --bg-alt: #efeadf;
  --surface: #fffdf8;
  --surface-2: #f1ece0;
  --border: #e0d8c8;
  --border-soft: #ebe4d6;
  --text: #1f2430;
  --text-dim: #4b5263;
  --text-mute: #6e7587;
  --link: #c2410c;
  --link-hover: #9a330a;
  --code-bg: #f1ece0;
  --code-text: #2a2f3a;
  --selection: rgba(255, 107, 61, 0.25);
  --on-accent: #160a04;
}

/* Auto theme follows the OS when the user hasn't chosen */
@media (prefers-color-scheme: light) {
  html[data-theme="auto"] {
    --bg: #f6f3ec;
    --bg-alt: #efeadf;
    --surface: #fffdf8;
    --surface-2: #f1ece0;
    --border: #e0d8c8;
    --border-soft: #ebe4d6;
    --text: #1f2430;
    --text-dim: #4b5263;
    --text-mute: #6e7587;
    --link: #c2410c;
    --link-hover: #9a330a;
    --code-bg: #f1ece0;
    --code-text: #2a2f3a;
    --selection: rgba(255, 107, 61, 0.25);
  }
}

/* ----- Reset / base ------------------------------------------------------ */
*,
*::before,
*::after {
  box-sizing: border-box;
}
* {
  margin: 0;
}
html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
  -webkit-text-size-adjust: 100%;
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  * {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 1.0625rem;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
::selection {
  background: var(--selection);
}
main {
  flex: 1;
}
img {
  max-width: 100%;
  height: auto;
  display: block;
}
a {
  color: var(--link);
  text-decoration-color: color-mix(in srgb, var(--link) 40%, transparent);
  text-underline-offset: 2px;
}
a:hover {
  color: var(--link-hover);
  text-decoration-color: currentColor;
}
h1,
h2,
h3,
h4 {
  line-height: 1.18;
  font-weight: 700;
  letter-spacing: -0.018em;
  text-wrap: balance;
}
.icon {
  width: 1.25em;
  height: 1.25em;
  vertical-align: middle;
  flex: none;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: clamp(1.1rem, 4vw, 2.5rem);
}
.muted {
  color: var(--text-mute);
}

/* ----- Skip link --------------------------------------------------------- */
.skip-link {
  position: absolute;
  left: 0.5rem;
  top: -3rem;
  z-index: 100;
  background: var(--accent);
  color: var(--on-accent);
  padding: 0.55rem 1rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: top var(--transition);
}
.skip-link:focus {
  top: 0.5rem;
  color: var(--on-accent);
}

/* ----- Header ------------------------------------------------------------ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--border-soft);
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  height: 4rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 800;
  font-size: 1.18rem;
  letter-spacing: -0.03em;
  color: var(--text);
  text-decoration: none;
}
.brand-mark {
  display: inline-flex;
}
.brand-mark svg {
  display: block;
}
.site-nav {
  margin-inline-start: auto;
}
.site-nav ul {
  display: flex;
  gap: 0.25rem;
  list-style: none;
  padding: 0;
}
.site-nav a {
  display: block;
  padding: 0.45rem 0.7rem;
  border-radius: var(--radius-sm);
  color: var(--text-dim);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: background var(--transition), color var(--transition);
}
.site-nav a:hover {
  color: var(--text);
  background: var(--surface);
}
.site-nav a[aria-current="page"] {
  color: var(--accent);
}
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}
.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.4rem;
  height: 2.4rem;
  border-radius: var(--radius-sm);
  border: 0;
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  text-decoration: none;
  transition: background var(--transition), color var(--transition);
}
.icon-btn:hover {
  background: var(--surface);
  color: var(--text);
}
.theme-toggle .icon-moon {
  display: none;
}
.theme-toggle .icon-sun {
  display: block;
}
html[data-theme="light"] .theme-toggle .icon-sun,
html[data-theme="dark"] .theme-toggle .icon-moon {
  display: block;
}
html[data-theme="light"] .theme-toggle .icon-moon,
html[data-theme="dark"] .theme-toggle .icon-sun {
  display: none;
}

/* Mobile nav */
.nav-toggle {
  display: none;
  margin-inline-start: auto;
  width: 2.6rem;
  height: 2.6rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

@media (max-width: 860px) {
  .nav-toggle {
    display: flex;
    order: 3;
  }
  .header-actions {
    order: 2;
  }
  .site-nav {
    order: 4;
    position: fixed;
    inset: 4rem 0 auto 0;
    margin: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition);
  }
  .site-nav ul {
    flex-direction: column;
    gap: 0;
    padding: 0.5rem clamp(1.1rem, 4vw, 2.5rem) 1.25rem;
  }
  .site-nav a {
    padding: 0.8rem 0.5rem;
    font-size: 1.05rem;
    border-bottom: 1px solid var(--border-soft);
    border-radius: 0;
  }
  /* No-JS fallback: the checkbox-hack. */
  .nav-toggle-cb:checked ~ .site-nav {
    max-height: 80vh;
  }
  .nav-toggle-cb:checked ~ .nav-toggle span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }
  .nav-toggle-cb:checked ~ .nav-toggle span:nth-child(2) {
    opacity: 0;
  }
  .nav-toggle-cb:checked ~ .nav-toggle span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  /* JS-enhanced: explicit class on the header (bulletproof style recalc). */
  .site-header.nav-open .site-nav {
    max-height: 80vh;
  }
  .site-header.nav-open .nav-toggle span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }
  .site-header.nav-open .nav-toggle span:nth-child(2) {
    opacity: 0;
  }
  .site-header.nav-open .nav-toggle span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }
}

/* ----- Buttons ----------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.98rem;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform var(--transition), background var(--transition),
    border-color var(--transition), color var(--transition);
}
.btn .icon {
  width: 1.1em;
  height: 1.1em;
}
.btn:hover {
  transform: translateY(-1px);
}
.btn-primary {
  background: var(--accent);
  color: var(--on-accent);
}
.btn-primary:hover {
  background: var(--accent-2);
  color: var(--on-accent);
}
.btn-ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}
.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ----- Hero -------------------------------------------------------------- */
.hero {
  padding: clamp(3.5rem, 9vw, 7rem) 0 clamp(2.5rem, 6vw, 4.5rem);
  background: radial-gradient(
      120% 120% at 80% -10%,
      color-mix(in srgb, var(--accent) 12%, transparent),
      transparent 60%
    ),
    var(--bg);
  border-bottom: 1px solid var(--border-soft);
}
.kicker {
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 1rem;
}
.hero-title {
  font-size: clamp(2.3rem, 6.5vw, 4.4rem);
  letter-spacing: -0.035em;
  max-width: 18ch;
}
.hero-title .accent {
  color: var(--accent);
}
.hero-lead {
  margin-top: 1.5rem;
  font-size: clamp(1.1rem, 2.2vw, 1.4rem);
  color: var(--text-dim);
  max-width: 46ch;
  line-height: 1.5;
}
.hero-actions {
  margin-top: 2rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}
.hero-foot {
  margin-top: 2.5rem;
  font-size: 0.95rem;
  color: var(--text-mute);
  max-width: 60ch;
  border-top: 1px solid var(--border-soft);
  padding-top: 1.5rem;
}

/* ----- Sections ---------------------------------------------------------- */
.section {
  padding: clamp(2.5rem, 6vw, 4.5rem) 0;
}
.section-alt {
  background: var(--bg-alt);
  border-block: 1px solid var(--border-soft);
}
.section-head {
  margin-bottom: 2rem;
  max-width: 60ch;
}
.section-head h2 {
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
}
.section-head p {
  margin-top: 0.6rem;
  color: var(--text-dim);
}
.section-head-row {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 1rem;
  max-width: none;
}
.link-more {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
}
.link-more .icon {
  width: 1em;
  height: 1em;
  transition: transform var(--transition);
}
.link-more:hover .icon {
  transform: translateX(3px);
}

/* Pull quote */
.section-quote {
  text-align: center;
}
.pull-quote {
  max-width: 30ch;
  margin-inline: auto;
}
.pull-quote p {
  font-family: var(--font-serif);
  font-size: clamp(1.7rem, 4.5vw, 2.8rem);
  line-height: 1.2;
  font-style: italic;
  letter-spacing: -0.02em;
}
.pull-quote cite {
  display: block;
  margin-top: 1.25rem;
  font-style: normal;
  font-size: 0.95rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  font-family: var(--font-sans);
}

/* ----- Topic cards ------------------------------------------------------- */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 20rem), 1fr));
  gap: 1rem;
}
.topic-card {
  display: flex;
  gap: 1rem;
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
  transition: transform var(--transition), border-color var(--transition),
    box-shadow var(--transition);
}
.topic-card:hover {
  transform: translateY(-3px);
  border-color: color-mix(in srgb, var(--accent) 50%, var(--border));
  box-shadow: var(--shadow);
  color: var(--text);
}
.topic-icon {
  flex: none;
  width: 2.9rem;
  height: 2.9rem;
  display: grid;
  place-items: center;
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  color: var(--accent);
}
.topic-icon .icon {
  width: 1.5rem;
  height: 1.5rem;
}
.topic-card-body {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}
.topic-card-kicker {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-mute);
  font-weight: 700;
}
.topic-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}
.topic-card-blurb {
  font-size: 0.95rem;
  color: var(--text-dim);
  line-height: 1.5;
}

/* ----- Essay cards ------------------------------------------------------- */
.essay-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 22rem), 1fr));
  gap: 1rem;
}
.essay-list {
  display: grid;
  gap: 1rem;
}
.essay-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform var(--transition), border-color var(--transition),
    box-shadow var(--transition);
}
.essay-card:hover {
  transform: translateY(-3px);
  border-color: color-mix(in srgb, var(--accent) 50%, var(--border));
  box-shadow: var(--shadow);
}
.essay-card-link {
  display: block;
  padding: 1.5rem;
  text-decoration: none;
  color: var(--text);
  height: 100%;
}
.essay-card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  align-items: center;
  font-size: 0.78rem;
  color: var(--text-mute);
  margin-bottom: 0.75rem;
}
.essay-card-topic {
  color: var(--accent);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.essay-card-title {
  font-size: 1.3rem;
  letter-spacing: -0.022em;
  margin-bottom: 0.55rem;
}
.essay-card-excerpt {
  color: var(--text-dim);
  font-size: 0.96rem;
  line-height: 1.55;
}
.essay-card-more {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-top: 1rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--accent);
}
.essay-card-more .icon {
  width: 1em;
  height: 1em;
  transition: transform var(--transition);
}
.essay-card:hover .essay-card-more .icon {
  transform: translateX(3px);
}
.essay-list-full .essay-card-title {
  font-size: 1.45rem;
}

/* ----- Idea chips & rows ------------------------------------------------- */
.idea-chip-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 16rem), 1fr));
  gap: 0.8rem;
}
.idea-chip {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  padding: 1rem 1.15rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--text);
  transition: border-color var(--transition), transform var(--transition);
}
.idea-chip:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  color: var(--text);
}
.idea-chip strong {
  font-weight: 700;
}
.idea-chip span {
  font-size: 0.86rem;
  color: var(--text-dim);
  line-height: 1.45;
}

/* ----- CTA --------------------------------------------------------------- */
.section-cta {
  padding: clamp(2.5rem, 6vw, 4rem) 0;
}
.cta-inner {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: clamp(1.5rem, 4vw, 2.75rem);
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  align-items: center;
  justify-content: space-between;
}
.cta-inner h2 {
  font-size: clamp(1.4rem, 3vw, 1.9rem);
}
.cta-inner p {
  margin-top: 0.5rem;
  color: var(--text-dim);
  max-width: 48ch;
}
.cta-actions {
  display: flex;
  gap: 0.7rem;
  flex-wrap: wrap;
}

/* ----- Page header ------------------------------------------------------- */
.page-header {
  padding: clamp(2.5rem, 6vw, 4.5rem) 0 clamp(1.5rem, 3vw, 2.5rem);
  border-bottom: 1px solid var(--border-soft);
  background: radial-gradient(
      100% 120% at 90% -20%,
      color-mix(in srgb, var(--accent) 9%, transparent),
      transparent 55%
    ),
    var(--bg);
}
.page-header h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  max-width: 22ch;
}
.page-header .lead,
.lead {
  margin-top: 1rem;
  font-size: clamp(1.05rem, 2vw, 1.3rem);
  color: var(--text-dim);
  max-width: 58ch;
  line-height: 1.5;
}

/* ----- Breadcrumbs ------------------------------------------------------- */
.breadcrumbs {
  padding-block: 1.5rem 0.5rem;
}
.breadcrumbs ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  list-style: none;
  padding: 0;
  font-size: 0.85rem;
  color: var(--text-mute);
}
.breadcrumbs li:not(:last-child)::after {
  content: "/";
  margin-inline-start: 0.4rem;
  color: var(--text-mute);
  opacity: 0.6;
}
.breadcrumbs a {
  text-decoration: none;
  color: var(--text-dim);
}
.breadcrumbs a:hover {
  color: var(--accent);
}
.breadcrumbs [aria-current="page"] {
  color: var(--text);
}

/* ----- Prose ------------------------------------------------------------- */
.prose {
  font-family: var(--font-serif);
  font-size: 1.18rem;
  line-height: 1.7;
  color: var(--text);
  max-width: var(--reading);
}
.prose > * + * {
  margin-top: 1.3rem;
}
.prose h2 {
  font-family: var(--font-sans);
  font-size: 1.6rem;
  margin-top: 2.8rem;
  padding-top: 0.4rem;
  scroll-margin-top: 5rem;
}
.prose h3 {
  font-family: var(--font-sans);
  font-size: 1.25rem;
  margin-top: 2rem;
  scroll-margin-top: 5rem;
}
.prose p,
.prose ul,
.prose ol {
  max-width: var(--reading);
}
.prose ul,
.prose ol {
  padding-inline-start: 1.4rem;
}
.prose li + li {
  margin-top: 0.5rem;
}
.prose a {
  font-weight: 500;
}
.prose strong {
  font-weight: 700;
  color: var(--text);
}
.prose blockquote {
  border-inline-start: 3px solid var(--accent);
  padding: 0.4rem 0 0.4rem 1.4rem;
  margin-inline: 0;
  font-style: italic;
  color: var(--text-dim);
  font-size: 1.22rem;
}
.prose code {
  font-family: var(--font-mono);
  font-size: 0.86em;
  background: var(--code-bg);
  padding: 0.15em 0.4em;
  border-radius: 5px;
  border: 1px solid var(--border-soft);
}
.prose pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1.1rem 1.25rem;
  overflow-x: auto;
  font-size: 0.92rem;
}
.prose pre code {
  background: none;
  border: 0;
  padding: 0;
  font-size: inherit;
  color: var(--code-text);
}
.prose hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin-block: 2.5rem;
}
.heading-anchor {
  margin-inline-start: 0.4rem;
  color: var(--text-mute);
  opacity: 0;
  text-decoration: none;
  font-weight: 400;
  transition: opacity var(--transition);
}
.prose h2:hover .heading-anchor,
.prose h3:hover .heading-anchor {
  opacity: 1;
}

/* ----- Essay layout ------------------------------------------------------ */
.essay-wrap {
  max-width: 60rem;
}
.essay-header {
  margin-block: 1rem 2.5rem;
}
.essay-topic-tag {
  display: inline-block;
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 700;
  color: var(--accent);
  text-decoration: none;
  margin-bottom: 1rem;
}
.essay-header h1 {
  font-size: clamp(2rem, 5vw, 3.1rem);
  letter-spacing: -0.03em;
}
.essay-subtitle {
  margin-top: 1rem;
  font-family: var(--font-serif);
  font-size: clamp(1.15rem, 2.4vw, 1.5rem);
  font-style: italic;
  color: var(--text-dim);
  line-height: 1.4;
  max-width: 50ch;
}
.essay-meta {
  margin-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  font-size: 0.9rem;
  color: var(--text-mute);
}
.essay-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
}
.essay-aside {
  display: none;
}
.essay-body {
  max-width: var(--reading);
}
@media (min-width: 1040px) {
  .essay-layout {
    grid-template-columns: 15rem 1fr;
    align-items: start;
  }
  .essay-aside {
    display: block;
    position: sticky;
    top: 5rem;
  }
}
.toc {
  font-size: 0.9rem;
  border-inline-start: 1px solid var(--border);
  padding-inline-start: 1.1rem;
}
.toc-title {
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-mute);
  margin-bottom: 0.8rem;
}
.toc ul {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.55rem;
}
.toc a {
  text-decoration: none;
  color: var(--text-dim);
  line-height: 1.35;
  display: block;
}
.toc a:hover {
  color: var(--accent);
}
.toc-l3 {
  padding-inline-start: 0.9rem;
  font-size: 0.85rem;
}
.essay-tags {
  margin-top: 2.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.tag {
  font-size: 0.78rem;
  padding: 0.28rem 0.7rem;
  border-radius: 999px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-dim);
}
.essay-related {
  margin-top: 4rem;
  padding-top: 2.5rem;
  border-top: 1px solid var(--border);
}
.essay-related h2 {
  font-size: 1.4rem;
  margin-bottom: 1.5rem;
}

/* ----- Topic hub --------------------------------------------------------- */
.topic-hub-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  margin-top: 1.5rem;
}
@media (min-width: 940px) {
  .topic-hub-grid {
    grid-template-columns: 1fr 18rem;
    align-items: start;
  }
}
.block-title {
  margin-top: 3rem;
  margin-bottom: 1.25rem;
  font-size: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}
.topic-hub-main .prose {
  max-width: none;
}
.aside-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.3rem 1.4rem;
  margin-bottom: 1.25rem;
}
.aside-box h2 {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-mute);
  margin-bottom: 0.9rem;
}
.aside-list {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}
.aside-list a {
  text-decoration: none;
  color: var(--text-dim);
}
.aside-list a:hover {
  color: var(--accent);
}

/* ----- Ideas index ------------------------------------------------------- */
.idea-filter {
  margin-block: 1.5rem 2rem;
}
.idea-filter input,
.search-box input {
  width: 100%;
  font-size: 1.05rem;
  padding: 0.85rem 1.1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
}
.idea-filter input:focus,
.search-box input:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
  border-color: var(--accent);
}
.idea-list-index {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--border-soft);
  margin-bottom: 3rem;
}
.idea-row {
  display: grid;
  grid-template-columns: minmax(9rem, 14rem) 1fr;
  gap: 1rem;
  padding: 1.1rem 0.75rem;
  text-decoration: none;
  color: var(--text);
  border-bottom: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}
.idea-row:hover {
  background: var(--surface);
  color: var(--text);
}
.idea-row-term {
  font-weight: 700;
  letter-spacing: -0.01em;
}
.idea-row-short {
  color: var(--text-dim);
  font-size: 0.96rem;
}
@media (max-width: 600px) {
  .idea-row {
    grid-template-columns: 1fr;
    gap: 0.25rem;
  }
}

/* ----- Idea page --------------------------------------------------------- */
.idea-page {
  max-width: 48rem;
}
.idea-article {
  margin-block: 1rem 4rem;
}
.idea-article h1 {
  font-size: clamp(2rem, 5vw, 2.8rem);
  margin-top: 0.5rem;
}
.idea-aka {
  margin-top: 0.5rem;
  color: var(--text-mute);
  font-size: 0.92rem;
  font-style: italic;
}
.idea-article .lead {
  margin-bottom: 1.5rem;
}
.idea-article .prose {
  max-width: none;
}
.idea-related {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}
.idea-related h2 {
  font-size: 1.3rem;
  margin-bottom: 1.25rem;
}
.back-link {
  margin-top: 2.5rem;
}
.back-link a {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  text-decoration: none;
  font-weight: 600;
}
.back-link .icon {
  width: 1em;
  transform: rotate(180deg);
}

/* ----- Timeline ---------------------------------------------------------- */
.timeline {
  list-style: none;
  padding: 0;
  margin-block: 2rem 4rem;
  position: relative;
  max-width: 52rem;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 5.5rem;
  top: 0.5rem;
  bottom: 0.5rem;
  width: 2px;
  background: var(--border);
}
.tl-item {
  display: grid;
  grid-template-columns: 5.5rem 1fr;
  gap: 1.5rem;
  padding-bottom: 2.25rem;
  position: relative;
}
.tl-year {
  font-weight: 800;
  font-size: 1.05rem;
  color: var(--accent);
  text-align: right;
  padding-top: 0.1rem;
}
.tl-body {
  position: relative;
  padding-inline-start: 1.5rem;
}
.tl-body::before {
  content: "";
  position: absolute;
  left: -0.4rem;
  top: 0.45rem;
  width: 0.85rem;
  height: 0.85rem;
  border-radius: 50%;
  background: var(--bg);
  border: 2px solid var(--accent);
}
.tl-body h3 {
  font-size: 1.18rem;
  letter-spacing: -0.015em;
}
.tl-who {
  color: var(--text-mute);
  font-size: 0.88rem;
  margin-top: 0.15rem;
  margin-bottom: 0.5rem;
}
.tl-body p {
  color: var(--text-dim);
  font-size: 0.98rem;
}
.tl-topic {
  display: inline-block;
  margin-top: 0.7rem;
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 700;
  text-decoration: none;
  color: var(--accent);
  opacity: 0.85;
}
@media (max-width: 620px) {
  .timeline::before {
    left: 0.4rem;
  }
  .tl-item {
    grid-template-columns: 1fr;
    gap: 0.4rem;
    padding-inline-start: 1.6rem;
  }
  .tl-year {
    text-align: left;
    padding-inline-start: 0;
  }
  .tl-body {
    padding-inline-start: 0;
  }
  .tl-body::before {
    left: -1.55rem;
  }
}

/* ----- Reading list ------------------------------------------------------ */
.reading-wrap {
  max-width: 52rem;
}
.reading-section {
  margin-top: 3rem;
}
.reading-section h2 {
  font-size: 1.6rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border);
  scroll-margin-top: 5rem;
}
.reading-blurb {
  margin-top: 0.9rem;
  color: var(--text-dim);
  max-width: 60ch;
}
.reading-list {
  list-style: none;
  padding: 0;
  margin-top: 1.5rem;
  display: grid;
  gap: 1rem;
}
.reading-item {
  display: grid;
  grid-template-columns: 4.5rem 1fr;
  gap: 1rem;
  padding: 1.1rem 1.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.reading-kind {
  font-size: 0.66rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 800;
  height: 1.55rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding-inline: 0.6rem;
  align-self: start;
}
.reading-kind-book {
  background: color-mix(in srgb, #6c8cff 22%, transparent);
  color: #9db4ff;
}
.reading-kind-paper {
  background: color-mix(in srgb, var(--accent) 22%, transparent);
  color: var(--accent);
}
.reading-kind-talk {
  background: color-mix(in srgb, #46d39a 22%, transparent);
  color: #5fd6a4;
}
.reading-kind-site {
  background: color-mix(in srgb, #c98cff 22%, transparent);
  color: #cfa3ff;
}
html[data-theme="light"] .reading-kind-book {
  color: #2b4ac0;
}
html[data-theme="light"] .reading-kind-talk {
  color: #128a5b;
}
html[data-theme="light"] .reading-kind-site {
  color: #7c2fc0;
}
.reading-meta h3 {
  font-size: 1.12rem;
  letter-spacing: -0.01em;
}
.reading-meta h3 a {
  text-decoration: none;
}
.reading-meta h3 a:hover {
  text-decoration: underline;
}
.reading-byline {
  color: var(--text-mute);
  font-size: 0.85rem;
  margin-top: 0.15rem;
}
.reading-note {
  color: var(--text-dim);
  font-size: 0.95rem;
  margin-top: 0.5rem;
  line-height: 1.5;
}
@media (max-width: 540px) {
  .reading-item {
    grid-template-columns: 1fr;
  }
}

/* ----- Search ------------------------------------------------------------ */
.search-box {
  position: relative;
  margin-block: 1.5rem 1rem;
}
.search-box .search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-mute);
  pointer-events: none;
}
.search-box input {
  padding-inline-start: 3rem;
  font-size: 1.15rem;
}
.search-status {
  color: var(--text-mute);
  font-size: 0.9rem;
  min-height: 1.2rem;
}
.search-results {
  display: grid;
  gap: 0.75rem;
  margin-block: 1.5rem 4rem;
}
.search-result {
  display: block;
  padding: 1.1rem 1.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
  transition: border-color var(--transition);
}
.search-result:hover {
  border-color: var(--accent);
  color: var(--text);
}
.search-result-type {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 800;
  color: var(--accent);
}
.search-result h3 {
  font-size: 1.12rem;
  margin-block: 0.3rem;
}
.search-result p {
  color: var(--text-dim);
  font-size: 0.92rem;
}
.search-result mark {
  background: color-mix(in srgb, var(--accent) 35%, transparent);
  color: inherit;
  padding: 0 0.1em;
  border-radius: 3px;
}

/* ----- Error page -------------------------------------------------------- */
.error-page {
  padding: clamp(4rem, 12vw, 8rem) 0;
  text-align: center;
}
.error-page h1 {
  font-size: clamp(2rem, 6vw, 3.4rem);
  max-width: 18ch;
  margin-inline: auto;
}
.error-page .lead {
  margin-inline: auto;
}
.error-page .hero-actions {
  justify-content: center;
}

/* ----- Footer ------------------------------------------------------------ */
.site-footer {
  margin-top: 4rem;
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding-block: clamp(2.5rem, 5vw, 3.5rem) 2rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}
@media (min-width: 720px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 2.5rem;
  }
}
.footer-about {
  max-width: 34ch;
}
.footer-about .brand {
  margin-bottom: 0.9rem;
}
.footer-about p {
  color: var(--text-dim);
  font-size: 0.92rem;
  line-height: 1.55;
}
.footer-feed {
  margin-top: 1rem;
}
.footer-feed a {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
}
.footer-feed .icon {
  width: 1.1em;
}
.footer-col h2 {
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-mute);
  margin-bottom: 1rem;
}
.footer-col ul {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}
.footer-col a {
  text-decoration: none;
  color: var(--text-dim);
  font-size: 0.92rem;
}
.footer-col a:hover {
  color: var(--accent);
}
.footer-bottom {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-soft);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem;
  color: var(--text-mute);
  font-size: 0.85rem;
}
.footer-note a {
  color: var(--text-dim);
}

/* ----- People ------------------------------------------------------------ */
.people-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 17rem), 1fr));
  gap: 1rem;
  margin: 1.75rem 0 3rem;
}
.person-card {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding: 1.1rem 1.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
  transition: border-color var(--transition), transform var(--transition);
}
.person-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}
.pc-name {
  font-weight: 700;
  font-size: 1.12rem;
  letter-spacing: -0.01em;
}
.pc-meta {
  color: var(--text-mute);
  font-size: 0.8rem;
}
.pc-life,
.person-life {
  font-variant-numeric: tabular-nums;
}
.pc-short {
  color: var(--text-dim);
  font-size: 0.94rem;
  line-height: 1.5;
  margin-top: 0.15rem;
}
.person-meta {
  color: var(--text-mute);
  font-size: 0.95rem;
  margin: 0.1rem 0 0.4rem;
}
.person-meta .dot {
  margin: 0 0.5rem;
  color: var(--border);
}

/* ----- Focus visibility -------------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 3px;
}