:root {
  --ink: #17201e;
  --muted: #5f6a67;
  --line: #dce2df;
  --paper: #ffffff;
  --accent: #315f58;
  --accent-soft: #e9f0ed;
  --link: #315f8f;
  --max-width: 800px;
  --body-font: "Source Sans 3", "Helvetica Neue", Arial, sans-serif;
  --heading-font: var(--body-font);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body-font);
  font-size: 16px;
  line-height: 1.58;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--link);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.16em;
}

a:hover {
  color: #193f68;
}

a:focus-visible {
  border-radius: 2px;
  outline: 3px solid rgba(49, 95, 143, 0.28);
  outline-offset: 3px;
}

h1,
h2,
h3,
p,
figure {
  margin-top: 0;
}

.site-frame {
  width: min(var(--max-width), calc(100% - 40px));
  margin: 0 auto;
}

.concept-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 28px;
  padding: 30px 0 17px;
  border-bottom: 1px solid var(--line);
}

.wordmark {
  flex: none;
  color: var(--ink);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.concept-header nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px 20px;
}

.concept-header nav a {
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

.concept-header nav a:hover {
  color: var(--ink);
}

.concept-header--nav-only {
  justify-content: flex-end;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 150px;
  gap: 54px;
  align-items: center;
  padding: 58px 0 52px;
}

.kicker,
.section-label,
.item-meta {
  color: var(--muted);
  font-size: 12px;
  font-weight: 650;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.kicker {
  margin-bottom: 8px;
}

.hero h1 {
  margin-bottom: 8px;
  font-family: var(--heading-font);
  font-size: clamp(38px, 6vw, 48px);
  font-weight: 650;
  letter-spacing: -0.035em;
  line-height: 1.05;
}

.role {
  margin-bottom: 2px;
  font-size: 19px;
  font-weight: 600;
}

.affiliation {
  margin-bottom: 18px;
  color: var(--muted);
}

.bio {
  max-width: 570px;
  margin-bottom: 17px;
  font-size: 17px;
}

.profile-links,
.resource-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 9px;
}

.profile-links a,
.resource-links a {
  font-weight: 600;
}

.profile-links span,
.resource-links span {
  color: #a0aaa7;
}

.portrait-wrap {
  width: 150px;
  margin: 0;
}

.portrait {
  display: block;
  width: 150px;
  height: 188px;
  border: 0;
  border-radius: 50%;
  object-fit: cover;
  object-position: 50% 38%;
}

.page-section {
  display: grid;
  grid-template-columns: 156px minmax(0, 1fr);
  gap: 30px;
  padding: 38px 0 42px;
  border-top: 1px solid var(--line);
}

.section-header {
  align-self: start;
}

.section-label {
  margin-bottom: 7px;
}

.section-header h2 {
  margin-bottom: 0;
  font-family: var(--heading-font);
  font-size: 24px;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.research-list,
.publication-list,
.writing-list,
.opensource-list {
  min-width: 0;
}

.research-item,
.opensource-item {
  padding: 0 0 22px;
}

.research-item:last-child,
.opensource-item:last-child {
  padding-bottom: 0;
}

.research-item h3,
.opensource-item h3,
.writing-item h3,
.publication-item h3 {
  margin-bottom: 4px;
  font-family: var(--heading-font);
  font-size: 18px;
  font-weight: 620;
  letter-spacing: -0.012em;
  line-height: 1.35;
}

.research-item p,
.opensource-item p,
.now-copy p {
  margin-bottom: 0;
  color: var(--muted);
}

.now-copy p + p {
  margin-top: 12px;
}

.publication-item {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 20px;
  padding: 0 0 28px;
}

.publication-item:last-child {
  padding-bottom: 0;
}

.publication-meta {
  display: flex;
  flex-direction: column;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.45;
}

.publication-meta span:first-child {
  color: var(--ink);
  font-weight: 650;
}

.publication-copy h3 {
  margin-bottom: 7px;
}

.authors {
  margin-bottom: 7px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
  overflow-wrap: anywhere;
}

.authors .author-self {
  color: var(--ink);
  font-weight: 750;
}

.author-note {
  margin: -1px 0 8px;
  color: var(--muted);
  font-size: 12px;
  font-style: italic;
}

.resource-links {
  font-size: 14px;
}

.opensource-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px 30px;
}

.opensource-item {
  padding-bottom: 0;
}

.opensource-item .item-meta {
  margin-bottom: 5px;
  font-size: 10px;
}

.opensource-item h3 a,
.writing-item h3 a {
  color: var(--ink);
  text-decoration: none;
}

.opensource-item h3 a:hover,
.writing-item h3 a:hover {
  color: var(--link);
}

.writing-item {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 18px;
  padding: 0 0 15px;
}

.writing-item time {
  padding-top: 2px;
  color: var(--muted);
  font-size: 13px;
}

.writing-item h3 {
  margin-bottom: 0;
  font-size: 17px;
}

.disclosure {
  margin-top: 10px;
  border-top: 1px solid var(--line);
}

.disclosure > summary {
  padding: 14px 0 2px;
  color: var(--link);
  cursor: pointer;
  font-size: 14px;
  font-weight: 650;
}

.disclosure > summary:hover {
  color: var(--ink);
}

.disclosure > summary:focus-visible {
  border-radius: 2px;
  outline: 3px solid rgba(49, 95, 143, 0.28);
  outline-offset: 3px;
}

.writing-list--expanded {
  margin-top: 18px;
}

.writing-disclosure {
  margin-top: 0;
  border-top: 0;
}

.career-groups {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 38px;
}

.career-group h3 {
  margin-bottom: 8px;
  font-size: 17px;
}

.career-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.career-list li {
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
}

.career-list article > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.career-list h4 {
  margin: 0;
  color: var(--ink);
  font-family: var(--heading-font);
  font-size: 14px;
  font-weight: 650;
  line-height: 1.4;
}

.career-list span {
  flex: none;
  color: var(--muted);
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.career-list p {
  margin: 5px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.section-action {
  grid-column: 2;
  margin: 18px 0 0;
  font-size: 14px;
}

.concept-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 24px 0 42px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
}

/* Shared cleaned About preview */

.about-frame {
  --max-width: 900px;
}

.about-preview {
  padding: 64px 0 10px;
}

.about-lead {
  display: grid;
  grid-template-columns: 208px minmax(0, 1fr);
  gap: 48px;
  align-items: center;
  padding-bottom: 56px;
}

.about-frame .about-lead .portrait-wrap,
.about-frame .about-lead .portrait {
  width: 208px;
}

.about-frame .about-lead .portrait {
  height: 260px;
}

.about-lead h1 {
  margin-bottom: 10px;
  font-size: clamp(40px, 6vw, 58px);
  letter-spacing: -0.05em;
  line-height: 1.04;
}

.about-lead h1 span {
  display: block;
  margin-top: 9px;
  color: var(--muted);
  font-size: 0.48em;
  font-weight: 560;
  letter-spacing: 0;
}

.about-section {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr);
  gap: 46px;
  padding: 52px 0 58px;
  border-top: 1px solid rgba(49, 95, 88, 0.2);
}

.bilingual-copy {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 38px;
}

.bilingual-copy article + article {
  padding-left: 38px;
  border-left: 1px solid var(--line);
}

.bilingual-copy h3 {
  margin-bottom: 12px;
  font-size: 17px;
}

.bilingual-copy p {
  margin-bottom: 16px;
  color: #3e4b47;
}

.experience-list {
  margin: 0;
}

.experience-list div {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 30px;
  padding: 17px 0;
  border-bottom: 1px solid var(--line);
}

.experience-list div:first-child {
  padding-top: 0;
}

.experience-list dt {
  font-weight: 650;
}

.experience-list dd {
  margin: 0;
  color: var(--muted);
}

.variant-switcher {
  position: fixed;
  z-index: 10;
  right: 18px;
  bottom: 18px;
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 7px;
  border: 1px solid #d7ddda;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 6px 24px rgba(24, 37, 33, 0.09);
  backdrop-filter: blur(10px);
}

.variant-switcher > span {
  padding: 0 6px;
  color: #65706d;
  font-size: 11px;
}

.variant-switcher a {
  display: inline-flex;
  width: 30px;
  height: 30px;
  align-items: center;
  justify-content: center;
  border-radius: 5px;
  color: #48534f;
  font-size: 11px;
  font-weight: 700;
  text-decoration: none;
}

.variant-switcher a:hover,
.variant-switcher a[aria-current='page'] {
  background: #e8efec;
  color: #244c45;
}

.variant-switcher .all-variants {
  width: auto;
  padding: 0 7px;
}

/* Modern minimal visual system */

html[data-visual='modern'] {
  --ink: #14201d;
  --muted: #68736f;
  --line: #d9e0dc;
  --paper: #f5f7f4;
  --accent: #315f58;
  --accent-soft: #e6efeb;
  --link: #315f58;
  --max-width: 960px;
  --body-font: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --heading-font: var(--body-font);
}

html[data-visual='modern'] body {
  background:
    linear-gradient(180deg, #eef3f0 0, #f7f8f6 360px, #f7f8f6 100%);
}

html[data-visual='modern'] .concept-header {
  padding-top: 25px;
  border-bottom-color: rgba(49, 95, 88, 0.18);
}

html[data-visual='modern'] .wordmark {
  font-size: 16px;
  letter-spacing: 0;
}

html[data-visual='modern'] .concept-header nav a {
  font-size: 13px;
  font-weight: 570;
}

html[data-visual='modern'] .hero {
  grid-template-columns: minmax(0, 1fr) 208px;
  gap: 72px;
  padding: 72px 0 66px;
}

html[data-visual='modern'] .kicker,
html[data-visual='modern'] .section-label,
html[data-visual='modern'] .item-meta {
  color: var(--accent);
  font-weight: 720;
  letter-spacing: 0.12em;
}

html[data-visual='modern'] .hero h1 {
  font-size: clamp(44px, 7vw, 64px);
  font-weight: 690;
  letter-spacing: -0.055em;
}

html[data-visual='modern'] .role {
  font-size: 20px;
}

html[data-visual='modern'] .bio {
  max-width: 610px;
  font-size: 17px;
}

html[data-visual='modern'] .portrait-wrap,
html[data-visual='modern'] .portrait {
  width: 208px;
}

html[data-visual='modern'] .portrait {
  height: 260px;
  border: 0;
  border-radius: 50%;
  box-shadow: none;
}

html[data-visual='modern'] .page-section {
  grid-template-columns: 180px minmax(0, 1fr);
  gap: 46px;
  padding: 52px 0 58px;
  border-top-color: rgba(49, 95, 88, 0.2);
}

html[data-visual='modern'] .section-header h2 {
  font-size: 28px;
  font-weight: 670;
}

html[data-visual='modern'] .research-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
}

html[data-visual='modern'] .research-item {
  padding: 0 24px;
  border-left: 1px solid var(--line);
}

html[data-visual='modern'] .research-item:first-child {
  padding-left: 0;
  border-left: 0;
}

html[data-visual='modern'] .research-item:last-child {
  padding-right: 0;
}

html[data-visual='modern'] .publication-item {
  grid-template-columns: 108px minmax(0, 1fr);
  gap: 28px;
  padding: 0 0 32px;
}

html[data-visual='modern'] .publication-item + .publication-item {
  padding-top: 28px;
  border-top: 1px solid rgba(49, 95, 88, 0.14);
}

html[data-visual='modern'] .publication-meta span:first-child {
  color: var(--accent);
}

html[data-visual='modern'] .publication-copy h3 {
  font-size: 19px;
  font-weight: 660;
}

html[data-visual='modern'] .opensource-list {
  gap: 34px 48px;
}

html[data-visual='modern'] .opensource-item {
  padding-left: 18px;
  border-left: 2px solid #b9cec5;
}

html[data-visual='modern'] .concept-footer {
  border-top-color: rgba(49, 95, 88, 0.2);
}

/* Single-page density gets slightly tighter repeated rows. */

html[data-density='single'] .page-section {
  padding-top: 44px;
  padding-bottom: 48px;
}

html[data-density='single'][data-visual='text'] .hero {
  padding-bottom: 46px;
}

/* Comparison hub */

.comparison-hub {
  width: min(980px, calc(100% - 40px));
  margin: 0 auto;
  padding: 72px 0;
}

.hub-kicker {
  margin-bottom: 10px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.comparison-hub h1 {
  max-width: 650px;
  margin-bottom: 16px;
  font-size: clamp(40px, 7vw, 66px);
  letter-spacing: -0.05em;
  line-height: 1;
}

.hub-intro {
  max-width: 650px;
  margin-bottom: 55px;
  color: var(--muted);
  font-size: 18px;
}

.comparison-axis {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-align: center;
  text-transform: uppercase;
}

.variant-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.variant-card {
  display: grid;
  min-height: 225px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  color: var(--ink);
  text-decoration: none;
  transition: border-color 150ms ease, transform 150ms ease;
}

.variant-card:hover {
  border-color: #91aaa1;
  color: var(--ink);
  transform: translateY(-2px);
}

.variant-card:nth-child(1),
.variant-card:nth-child(3) {
  border-radius: 2px;
  font-family: "Source Sans 3", "Helvetica Neue", Arial, sans-serif;
}

.variant-card:nth-child(2),
.variant-card:nth-child(4) {
  background: #eef3f0;
}

.variant-code {
  color: var(--accent);
  font-size: 34px;
  font-weight: 750;
  line-height: 1;
}

.variant-density {
  align-self: end;
  color: var(--muted);
  font-size: 13px;
}

.variant-card strong {
  font-size: 22px;
}

.variant-open {
  align-self: end;
  color: var(--link);
  font-size: 13px;
  font-weight: 650;
}

.hub-note {
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 820px) {
  .hero,
  html[data-visual='modern'] .hero {
    grid-template-columns: minmax(0, 1fr) 150px;
    gap: 36px;
  }

  html[data-visual='modern'] .portrait-wrap,
  html[data-visual='modern'] .portrait {
    width: 150px;
  }

  html[data-visual='modern'] .portrait {
    height: 188px;
    box-shadow: none;
  }

  html[data-visual='modern'] .research-list {
    grid-template-columns: 1fr;
  }

  html[data-visual='modern'] .research-item,
  html[data-visual='modern'] .research-item:first-child,
  html[data-visual='modern'] .research-item:last-child {
    padding: 0 0 20px;
    border-left: 0;
  }
}

@media (max-width: 680px) {
  .site-frame {
    width: min(100% - 32px, var(--max-width));
  }

  .concept-header {
    align-items: flex-start;
    padding-top: 22px;
  }

  .concept-header nav {
    gap: 8px 13px;
  }

  .hero,
  html[data-visual='modern'] .hero {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 42px 0 44px;
  }

  .portrait-wrap,
  html[data-visual='modern'] .portrait-wrap {
    grid-row: 1;
    width: 112px;
  }

  .portrait,
  html[data-visual='modern'] .portrait {
    width: 112px;
    height: 140px;
  }

  .hero h1,
  html[data-visual='modern'] .hero h1 {
    font-size: 40px;
  }

  .page-section,
  html[data-visual='modern'] .page-section {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 36px 0 40px;
  }

  .section-action {
    grid-column: 1;
  }

  .opensource-list {
    grid-template-columns: 1fr;
  }

  .career-groups {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .publication-item,
  html[data-visual='modern'] .publication-item {
    grid-template-columns: 1fr;
    gap: 9px;
  }

  .publication-meta {
    flex-direction: row;
    gap: 8px;
  }

  .publication-meta span + span::before {
    margin-right: 8px;
    color: #a5aeab;
    content: '·';
  }

  .variant-switcher {
    right: 10px;
    bottom: 10px;
  }

  .variant-switcher > span {
    display: none;
  }

  .comparison-hub {
    width: min(100% - 32px, 980px);
    padding: 48px 0;
  }

  .comparison-axis {
    display: none;
  }

  .variant-grid {
    grid-template-columns: 1fr;
  }

  .about-preview {
    padding-top: 42px;
  }

  .about-lead,
  .about-section {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .about-frame .about-lead .portrait-wrap,
  .about-frame .about-lead .portrait {
    width: 128px;
  }

  .about-frame .about-lead .portrait {
    height: 160px;
  }

  .bilingual-copy {
    grid-template-columns: 1fr;
  }

  .bilingual-copy article + article {
    padding: 28px 0 0;
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .experience-list div {
    grid-template-columns: 1fr;
    gap: 4px;
  }
}

@media (max-width: 430px) {
  .concept-header {
    display: block;
  }

  .wordmark {
    display: inline-block;
    margin-bottom: 13px;
  }

  .concept-header nav {
    justify-content: flex-start;
  }

  .concept-header--nav-only {
    display: flex;
    justify-content: flex-start;
  }

  .role {
    font-size: 18px;
  }

  .bio {
    font-size: 16px;
  }

  .writing-item {
    grid-template-columns: 76px minmax(0, 1fr);
    gap: 12px;
  }

  .concept-footer {
    display: block;
  }

  .concept-footer span {
    display: block;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}