@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500&family=Instrument+Sans:ital,wght@0,400;0,500;0,600;0,700;1,400&display=swap");

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root,
:root[data-theme="light"] {
  --bg: #ffffff;
  --surface: #ffffff;
  --text: #121820;
  --muted: #5a6578;
  --line: #cdd6e0;
  --accent: #2563eb;
  --link: #2563eb;
  --on-accent: #ffffff;
  --invert-bg: #121820;
  --invert-fg: #ffffff;
  --max: 56rem;
  --max-wide: 88rem;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --duration: 0.65s;
  --ease-reveal: cubic-bezier(0.16, 1, 0.3, 1);
  --duration-reveal: 0.82s;
  color-scheme: light;
}

:root[data-theme="dark"] {
  --bg: #000000;
  --surface: #111111;
  --text: #e8e8e8;
  --muted: #888888;
  --line: #2a2a2a;
  --accent: #2563eb;
  --link: #2563eb;
  --on-accent: #ffffff;
  --invert-bg: #ffffff;
  --invert-fg: #000000;
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]):not([data-theme="dark"]) {
    --bg: #000000;
    --surface: #111111;
    --text: #e8e8e8;
    --muted: #888888;
    --line: #2a2a2a;
    --accent: #2563eb;
    --link: #2563eb;
    --on-accent: #ffffff;
    --invert-bg: #ffffff;
    --invert-fg: #000000;
    color-scheme: dark;
  }
}

html {
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: "Instrument Sans", system-ui, sans-serif;
  font-size: 1.05rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
}

a {
  color: var(--link);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.15em;
}

a:hover {
  color: var(--accent);
}

::selection {
  background: var(--accent);
  color: var(--on-accent);
}

/* —— theme toggle —— */

.site-header-bar {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 2rem;
}

.site-header-bar--home {
  justify-content: flex-end;
  margin-bottom: 0;
}

.site-header-bar:has(+ article > .post-header) {
  margin-bottom: 0.35rem;
}

.site-header-bar:has(.xyzt-header) {
  align-items: center;
}

.site-header-bar .breadcrumb {
  margin-bottom: 0;
  min-width: 0;
  flex: 1;
}

.theme-toggle {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  align-self: center;
  width: 1.625rem;
  height: 1.625rem;
  padding: 0.25rem;
  border: none;
  background: none;
  color: var(--muted);
  cursor: pointer;
  line-height: 0;
  transition: color var(--duration) var(--ease);
}

.theme-toggle__icon {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: rotate(-35deg) scale(0.72);
  transition:
    opacity calc(var(--duration) * 0.85) var(--ease),
    transform calc(var(--duration) * 0.85) var(--ease);
  pointer-events: none;
}

.theme-toggle__icon svg {
  display: block;
}

.theme-toggle[data-theme-state="dark"] .theme-toggle__icon--dark,
.theme-toggle[data-theme-state="light"] .theme-toggle__icon--light {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

@media (prefers-reduced-motion: reduce) {
  .theme-toggle__icon {
    transform: none;
    transition: opacity 0.15s ease;
  }

  .theme-toggle[data-theme-state="dark"] .theme-toggle__icon--dark,
  .theme-toggle[data-theme-state="light"] .theme-toggle__icon--light {
    transform: none;
  }
}

.theme-toggle:hover {
  color: var(--text);
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--link);
  outline-offset: 2px;
}

/* —— layout —— */

.site {
  max-width: var(--max);
  margin: 0 auto;
  padding: 3rem 1.25rem 4rem;
}

/* —— home —— */

.intro {
  display: flex;
  align-items: flex-start;
  gap: 1.25rem 1.5rem;
  flex-wrap: wrap;
  margin-bottom: 0;
}

.intro-main {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.avatar {
  width: 8rem;
  height: 8rem;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
  border: 1px solid var(--line);
}

.identity h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.35rem;
  line-height: 1.2;
}

.tagline {
  color: var(--muted);
  font-size: 1.05rem;
}

.intro .links {
  display: flex;
  flex-wrap: wrap;
  align-items: stretch;
  gap: 0.5rem;
  margin-top: 0;
  font-size: 0.875rem;
  overflow: visible;
}

.links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  color: var(--muted);
  text-decoration: none;
  padding: 0.4rem 0.65rem;
  border: 1px solid var(--line);
  border-radius: 9999px;
  background-color: transparent;
  transition:
    background-color var(--duration) var(--ease),
    border-color calc(var(--duration) * 0.85) var(--ease),
    color calc(var(--duration) * 0.85) var(--ease);
}

.links .link-icon {
  width: 0.95em;
  height: 0.95em;
  flex-shrink: 0;
  opacity: 0.85;
  transition: opacity var(--duration) var(--ease);
}

.links a[aria-label="Social Media"] .link-icon,
.links a[aria-label="Code"] .link-icon {
  width: 1.15em;
  height: 1.15em;
}

.links a.link-expand {
  position: relative;
  z-index: 1;
  white-space: nowrap;
  gap: 0;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.8rem;
}

.links a.link-expand:hover,
.links a.link-expand:focus-visible {
  z-index: 20;
}

.link-expand__suffix {
  display: inline-block;
  min-width: 0;
  max-width: 0;
  overflow: hidden;
  vertical-align: bottom;
  margin-left: 0;
  transition:
    max-width var(--duration) var(--ease),
    margin-left var(--duration) var(--ease);
}

.links a.link-expand:hover .link-expand__suffix,
.links a.link-expand:focus-visible .link-expand__suffix {
  max-width: 12em;
  margin-left: 0.35rem;
}

.links .logo-xyzt {
  height: 1rem;
  width: auto;
  flex-shrink: 0;
  opacity: 0.85;
  display: block;
  transition: opacity var(--duration) var(--ease);
}

.links a:hover:not(.xyzt-pill) {
  background-color: var(--link);
  border-color: var(--link);
  color: var(--on-accent);
  text-decoration: none;
}

.links a:hover .link-icon,
.links a:hover .logo-xyzt {
  opacity: 1;
}

.links a.link-expand:hover,
.links a.link-expand:focus-visible {
  background-color: var(--invert-bg);
  border-color: var(--invert-bg);
  color: var(--invert-fg);
}

.xyzt-header {
  display: grid;
  grid-template-columns: 1fr;
  align-items: center;
  margin-bottom: 0;
  flex: 1;
  min-width: 0;
  width: 100%;
}

.xyzt-header__logo {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  grid-column: 1;
  grid-row: 1;
  justify-self: start;
  z-index: 1;
  padding: 0.35rem 0.55rem;
  border-radius: 9999px;
  font-size: clamp(2.25rem, 1.5rem + 2.5vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1;
  color: var(--text);
  text-decoration: none;
  background-color: transparent;
  transition:
    background-color var(--duration) var(--ease),
    color var(--duration) var(--ease);
}

.xyzt-header__logo:hover,
.xyzt-header__logo:focus-visible {
  background-color: var(--invert-bg);
  color: var(--invert-fg);
}

.xyzt-header__logo .logo-xyzt {
  height: 1em;
  width: auto;
  display: block;
}

.xyzt-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  grid-column: 1;
  grid-row: 1;
  justify-self: center;
  width: max-content;
  max-width: 100%;
  margin-top: 0;
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: normal;
  line-height: normal;
}

.xyzt-pill {
  font: inherit;
  transition:
    background-color var(--duration) var(--ease),
    border-color calc(var(--duration) * 0.85) var(--ease),
    color calc(var(--duration) * 0.85) var(--ease),
    filter var(--duration) var(--ease);
}

.xyzt-nav .xyzt-pill:not(.xyzt-pill--active):not([aria-current="page"]) {
  border-color: transparent;
}

.xyzt-nav .xyzt-pill:not(.xyzt-pill--active):not([aria-current="page"]):hover,
.xyzt-nav .xyzt-pill:not(.xyzt-pill--active):not([aria-current="page"]):focus-visible {
  background-color: transparent;
  border-color: var(--line);
  color: var(--muted);
}

.xyzt-pill--active,
.xyzt-pill[aria-current="page"] {
  background-color: var(--link);
  border-color: var(--link);
  color: var(--on-accent);
}

.xyzt-nav .xyzt-pill--active:hover,
.xyzt-nav .xyzt-pill--active:focus-visible,
.xyzt-nav .xyzt-pill[aria-current="page"]:hover,
.xyzt-nav .xyzt-pill[aria-current="page"]:focus-visible {
  background-color: var(--link);
  border-color: var(--link);
  color: var(--on-accent);
  filter: brightness(1.12);
}

.xyzt-pill--active .link-icon,
.xyzt-pill[aria-current="page"] .link-icon {
  opacity: 1;
}

.xyzt-pill .link-icon {
  opacity: 0.85;
  transition: opacity var(--duration) var(--ease);
}

.xyzt-pill:hover .link-icon,
.xyzt-pill:focus-visible .link-icon {
  opacity: 1;
}

body.xyzt-page .site--xyzt {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.xyzt-hero {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem 1.25rem 3rem;
  text-align: center;
}

.xyzt-hero[data-md] {
  justify-content: center;
  padding: 2rem 1.25rem 3rem;
}

.xyzt-hero[data-md].is-revealed {
  justify-content: flex-start;
  padding-top: 2.5rem;
}

.xyzt-hero__intro {
  width: 100%;
  max-width: 42rem;
}

.xyzt-hero[data-md].is-revealed .xyzt-hero__intro {
  margin-bottom: 1.75rem;
}

.xyzt-project-reveal {
  width: 100%;
  max-width: 42rem;
  overflow: hidden;
}

.xyzt-project-reveal:not(.is-visible) {
  visibility: hidden;
  pointer-events: none;
}

.xyzt-project-content {
  text-align: left;
  opacity: 0;
  transform: translate3d(0, 2.5rem, 0);
  transition:
    transform var(--duration-reveal) var(--ease-reveal),
    opacity calc(var(--duration-reveal) * 0.9) var(--ease-reveal);
}

.xyzt-project-reveal.is-visible {
  visibility: visible;
  pointer-events: auto;
}

.xyzt-project-reveal.is-visible .xyzt-project-content {
  opacity: 1;
  transform: translate3d(0, 0, 0);
}

.xyzt-hero.is-typing-done .xyzt-typewriter-cursor,
.xyzt-hero.is-revealed .xyzt-typewriter-cursor {
  opacity: 0;
  animation: none;
  transition: opacity 0.28s var(--ease-reveal);
}

.xyzt-tagline {
  max-width: 42rem;
  margin: 0 auto;
  font-size: clamp(1.2rem, 1rem + 1.2vw, 1.65rem);
  font-weight: 600;
  line-height: 1.45;
  letter-spacing: -0.02em;
  color: var(--text);
}

.xyzt-project {
  max-width: 42rem;
  margin: 0 auto;
}

.xyzt-page-title {
  font-size: clamp(2rem, 1.5rem + 2vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
  color: var(--text);
}

.xyzt-page-lead {
  margin-top: 0.5rem;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.85rem;
  color: var(--muted);
}

.xyzt-typewriter {
  display: inline;
  white-space: pre-wrap;
}

.xyzt-char {
  display: inline;
  opacity: 0;
  transform: translate3d(0, 0.05em, 0);
  transition:
    opacity 90ms cubic-bezier(0.22, 1, 0.36, 1),
    transform 90ms cubic-bezier(0.22, 1, 0.36, 1);
  will-change: opacity, transform;
}

.xyzt-char--space {
  display: inline-block;
  min-width: 0.28em;
}

.xyzt-char.is-visible {
  opacity: 1;
  transform: translate3d(0, 0, 0);
}

.xyzt-typewriter-cursor {
  display: inline-block;
  width: 2px;
  height: 0.95em;
  margin-left: 0;
  background: currentColor;
  vertical-align: baseline;
  transform: translate3d(0, 0.06em, 0);
  animation: xyzt-cursor-pulse 1.15s ease-in-out infinite;
  transition: opacity 0.28s var(--ease-reveal);
  will-change: opacity;
}

@keyframes xyzt-cursor-pulse {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.18;
  }
}

.xyzt-footer {
  margin-top: auto;
  padding-top: 3rem;
  text-align: center;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.75rem;
  color: var(--muted);
}

.xyzt-footer p {
  margin: 0;
}

.xyzt-footer a {
  color: inherit;
  text-decoration: none;
}

.xyzt-footer a:hover {
  color: var(--link);
}

@media (max-width: 640px) {
  .intro {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 1rem 1.25rem;
    align-items: start;
  }

  .intro-main {
    display: contents;
  }

  .avatar {
    grid-column: 1;
    grid-row: 1;
    width: 5.5rem;
    height: 5.5rem;
  }

  .identity {
    grid-column: 2;
    grid-row: 1;
  }

  .intro .links {
    grid-column: 1 / -1;
    grid-row: 2;
  }
}

.section-title {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--line);
}

.post-list {
  list-style: none;
}

.post-list li + li {
  margin-top: 0.15rem;
}

.post-list a {
  display: block;
  padding: 0.65rem 0;
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
}

.post-list a:hover {
  color: var(--link);
}

.post-list li:last-child a {
  border-bottom: none;
}

.post-title {
  font-weight: 600;
  font-size: 1.05rem;
}

.post-meta {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.75rem;
  color: var(--muted);
  margin-top: 0.2rem;
}

.post-list .pinned .post-meta {
  text-transform: lowercase;
}

/* —— breadcrumb —— */

.breadcrumb {
  margin-bottom: 2rem;
}

.site-header-bar + article > .post-header {
  margin-top: 0;
  margin-bottom: 1.25rem;
}

.breadcrumb ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  font-size: clamp(1.5rem, 1rem + 1.5vw, 1.85rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.3;
}

.breadcrumb li {
  display: flex;
  align-items: baseline;
}

.breadcrumb li:not(:first-child)::before {
  content: "/";
  margin: 0 0.28em;
  color: var(--muted);
  font-weight: 400;
}

.breadcrumb a {
  color: var(--text);
  text-decoration: none;
}

.breadcrumb a:hover:not(.xyzt-pill):not(.xyzt-header__logo) {
  color: var(--link);
}

.breadcrumb .xyzt-header__logo:hover,
.breadcrumb .xyzt-header__logo:focus-visible {
  color: var(--invert-fg);
}

.breadcrumb .links a:hover:not(.xyzt-pill) {
  color: var(--on-accent);
}

.breadcrumb .links .xyzt-pill:not(.xyzt-pill--active):not([aria-current="page"]):hover,
.breadcrumb .links .xyzt-pill:not(.xyzt-pill--active):not([aria-current="page"]):focus-visible {
  background-color: transparent;
  border-color: var(--line);
  color: var(--muted);
}

.breadcrumb .links .xyzt-pill:not(.xyzt-pill--active):not([aria-current="page"]) {
  color: var(--muted);
}

.breadcrumb .links .xyzt-pill--active:hover,
.breadcrumb .links .xyzt-pill--active:focus-visible,
.breadcrumb .links .xyzt-pill[aria-current="page"]:hover,
.breadcrumb .links .xyzt-pill[aria-current="page"]:focus-visible {
  color: var(--on-accent);
}

.breadcrumb .links a.xyzt-pill--active,
.breadcrumb .links a[aria-current="page"] {
  color: var(--on-accent);
}

.breadcrumb li[aria-current="page"] {
  color: var(--muted);
  align-items: center;
}

.breadcrumb .logo-xyzt {
  height: 0.72em;
  width: auto;
  display: block;
}

/* —— article —— */

.post-date {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.75rem;
  color: var(--muted);
}

.post-body h2,
.post-body h3 {
  font-weight: 700;
  margin: 2rem 0 0.75rem;
  line-height: 1.3;
}

.post-body h2 {
  font-size: 1.25rem;
}

.post-body h3 {
  font-size: 1.1rem;
}

.post-body p {
  margin-bottom: 1rem;
}

.post-body ul,
.post-body ol {
  margin: 0 0 1rem 1.25rem;
}

.post-body li {
  margin-bottom: 0.35rem;
}

.post-body blockquote {
  margin: 1.25rem 0;
  padding-left: 1rem;
  border-left: 2px solid var(--line);
  color: var(--muted);
  font-style: italic;
}

.post-body img {
  max-width: 100%;
  height: auto;
  border-radius: 2px;
  border: 1px solid var(--line);
}

.post-body figure:not(.about-photo) {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: fit-content;
  max-width: 100%;
  margin: 1.25rem auto;
}

.post-body figure:not(.about-photo) img {
  margin: 0;
  display: block;
}

.post-body > img {
  display: block;
  margin: 1.25rem auto;
}

.post-body figcaption {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem;
  color: var(--muted);
  margin-top: 0.4rem;
  text-align: center;
}

.post-body#about-content .about-photos {
  --photos-width: min(var(--max-wide), calc(100vw - 2.5rem));
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: flex-start;
  gap: 1rem 1.5rem;
  width: var(--photos-width);
  max-width: var(--photos-width);
  margin: 1.25rem calc((100% - var(--photos-width)) / 2) 1.5rem;
}

.post-body#about-content .about-photo,
.post-body#about-content figure.about-photo {
  display: block;
  flex: 1 1 14rem;
  max-width: 17rem;
  margin: 1.25rem 0 1.5rem;
}

.post-body#about-content .about-photos .about-photo,
.post-body#about-content .about-photos figure.about-photo {
  flex: 1 1 calc(25% - 1.125rem);
  min-width: 14rem;
  max-width: none;
  margin: 0;
  border-radius: 0.5rem;
  overflow: hidden;
}

.post-body#about-content .about-photos .about-photo img {
  display: block;
  width: 100%;
  height: 22rem;
  max-width: none;
  max-height: none;
  object-fit: cover;
  object-position: center;
  margin: 0;
  border-radius: 0.5rem;
}

.post-body#about-content .about-photo figcaption {
  text-align: left;
}

.post-body pre {
  overflow-x: auto;
  margin: 1.25rem 0;
  padding: 1rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 2px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.8rem;
  line-height: 1.5;
}

.post-body code {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.88em;
}

.post-body p code {
  padding: 0.1em 0.35em;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 2px;
}

.post-body pre code {
  padding: 0;
  border: none;
  background: none;
}

.post-body .katex-display {
  margin: 1.25rem 0;
  overflow-x: auto;
  overflow-y: hidden;
}

:root[data-theme="dark"] .post-body .invert-dark {
  filter: invert(1);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]):not([data-theme="dark"]) .post-body .invert-dark {
    filter: invert(1);
  }
}

@media (max-width: 480px) {
  .site {
    padding-top: 2rem;
  }

  .identity h1 {
    font-size: 1.5rem;
  }
}