/*
  Layout and type follow chojeq.com. The light palette below is that site's
  exact colors; they are variables only so the dark theme can swap them.
  Sections after "Content pages" cover things that site never needed:
  long-form posts, footnotes, tables, the syllabus, and the theme toggle.
*/

:root {
  --bg: #fff;
  --text: #1a1a1a;
  --text-2: #333;
  --text-3: #555;
  --text-4: #888;
  --rule: #eee;
  --line: #ccc;
  --line-2: #ddd;
  --note-bg: #f8f9fa;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #16181d;
  --text: #ececec;
  --text-2: #d2d2d2;
  --text-3: #b0b0b0;
  --text-4: #8b9098;
  --rule: #2a2d34;
  --line: #4d525b;
  --line-2: #3a3e46;
  --note-bg: #1e2228;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  border-bottom-color: var(--text);
}

a:focus-visible {
  outline: 2px solid var(--text);
  outline-offset: 2px;
}

/* Theme toggle */
.theme-toggle {
  position: fixed;
  top: 1.1rem;
  right: 1.25rem;
  z-index: 10;
  background: none;
  border: 0;
  padding: 0.4rem;
  border-radius: 6px;
  color: var(--text-4);
  cursor: pointer;
  line-height: 0;
}

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

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

.theme-toggle .icon-sun {
  display: none;
}

:root[data-theme="dark"] .theme-toggle .icon-moon {
  display: none;
}

:root[data-theme="dark"] .theme-toggle .icon-sun {
  display: inline;
}

/* Main section */
.main {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4rem 2rem;
}

.main-content {
  display: flex;
  align-items: center;
  gap: 4rem;
  max-width: 900px;
  width: 100%;
}

.details {
  flex: 1;
}

.details h1 {
  font-size: 2rem;
  font-weight: 600;
  margin-bottom: 1.2rem;
  letter-spacing: -0.02em;
}

.details p {
  margin-bottom: 1rem;
  font-size: 0.95rem;
  color: var(--text-2);
}

.links {
  margin-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.2rem;
}

.links a {
  font-size: 0.9rem;
  color: var(--text-3);
  border-bottom: 1px solid var(--line-2);
}

.links a:hover {
  color: var(--text);
  border-bottom-color: var(--text);
}

.portrait {
  flex-shrink: 0;
  width: 280px;
}

.portrait img {
  width: 100%;
  height: auto;
  display: block;
}

/* Research section */
.research {
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 2rem 4rem;
}

.research h2 {
  font-size: 1.4rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  letter-spacing: -0.02em;
}

.research ul + h2 {
  margin-top: 2.5rem;
}

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

.paper-list li {
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--rule);
  font-size: 0.9rem;
  color: var(--text-3);
}

.paper-row {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
}

.paper-info {
  flex: 1;
}

.paper-info em {
  display: block;
  margin-top: 0.15rem;
}

.date {
  flex-shrink: 0;
  color: var(--text-4);
  font-size: 0.85rem;
  white-space: nowrap;
}

.paper-list li a {
  border-bottom: none;
}

.paper-list li a:hover {
  border-bottom: 1px solid var(--text);
}

.paper-list li strong {
  color: var(--text);
}

.coauthors {
  display: block;
  font-size: 0.82rem;
  color: var(--text-4);
  margin-top: 0.1rem;
}

.paper-links {
  margin-left: 0.2rem;
}

.paper-links a {
  font-size: 0.85rem;
  color: var(--text-3);
  text-decoration: underline;
  text-underline-offset: 2px;
  border-bottom: none;
  margin-right: 0.15rem;
}

.paper-list li .paper-links a:hover {
  color: var(--text);
  border-bottom: none;
}

/* Content pages: writings, posts, teaching, contact */
.page {
  max-width: 700px;
  margin: 0 auto;
  padding: 6rem 2rem;
}

.page h1 {
  font-size: 2rem;
  font-weight: 600;
  line-height: 1.25;
  margin-bottom: 1.5rem;
  letter-spacing: -0.02em;
}

.page h2 {
  font-size: 1.35rem;
  font-weight: 600;
  margin: 2.5rem 0 1rem;
  letter-spacing: -0.02em;
}

.page h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 2rem 0 0.75rem;
}

.page h4 {
  font-size: 1rem;
  font-weight: 600;
  margin: 1.5rem 0 0.5rem;
}

.page p {
  font-size: 0.95rem;
  color: var(--text-2);
  margin-bottom: 1rem;
}

.page ul:not(.paper-list),
.page ol {
  padding-left: 1.4rem;
  margin-bottom: 1rem;
  font-size: 0.95rem;
  color: var(--text-2);
}

.page li {
  margin-bottom: 0.5rem;
}

.page .paper-list li {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 2rem;
  margin-bottom: 0;
}

.page .back {
  margin-top: 2.5rem;
}

.page img {
  max-width: 100%;
  height: auto;
}

.page blockquote {
  border-left: 3px solid var(--line);
  padding-left: 1rem;
  margin: 1rem 0;
  color: var(--text-3);
}

.page code {
  font-size: 0.85em;
}

.page pre {
  overflow-x: auto;
  margin-bottom: 1rem;
}

.page hr {
  border: 0;
  border-top: 1px solid var(--rule);
  margin: 2rem 0;
}

.page table {
  display: block;
  max-width: 100%;
  overflow-x: auto;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.9rem;
}

.page th,
.page td {
  padding: 0.5rem 0.75rem;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--rule);
}

.page th {
  font-weight: 600;
  border-bottom-color: var(--line);
}

/* Individual post */
.entry-header {
  margin-bottom: 2rem;
}

.entry-header h1 {
  margin-bottom: 0.5rem;
}

.entry-date,
.entry-authors {
  color: var(--text-4);
  font-size: 0.85rem;
}

.entry-authors {
  margin-top: 0.15rem;
}

.post-content sup {
  font-size: 0.75rem;
  line-height: 0;
}

.post-content sup a.footnote {
  border-bottom: none;
  color: var(--text-3);
}

.footnotes {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
}

.footnotes ol {
  padding-left: 1.4rem;
}

.footnotes li {
  font-size: 0.82rem;
  color: var(--text-3);
  margin-bottom: 0.6rem;
}

.footnotes li p {
  display: inline;
  margin-bottom: 0;
  font-size: inherit;
  color: inherit;
}

.footnotes a.reversefootnote {
  margin-left: 0.25rem;
  border-bottom: none;
}

.references {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
  font-size: 0.82rem;
  color: var(--text-3);
}

/* Teaching / syllabus */
.course-info {
  font-size: 0.95rem;
  color: var(--text-3);
  margin-bottom: 2rem;
}

.week-section {
  margin-top: 2.2rem;
}

.page .week-title {
  font-size: 1.05rem;
  font-weight: 600;
  margin: 0 0 0.75rem;
}

.reading-list li {
  margin-bottom: 0.6rem;
}

.prereq-note {
  background: var(--note-bg);
  padding: 1rem 1.25rem;
  border-left: 3px solid var(--line);
  margin: 1.5rem 0;
  font-size: 0.95rem;
  color: var(--text-2);
}

/* Responsive */
@media (max-width: 768px) {
  .main {
    padding: 3rem 1.5rem;
  }

  .main-content {
    flex-direction: column-reverse;
    gap: 2rem;
  }

  .portrait {
    width: 200px;
  }

  .details h1 {
    font-size: 1.6rem;
    text-align: center;
  }

  .research {
    padding: 1.5rem 1.5rem 3rem;
  }

  .page {
    padding: 4rem 1.5rem;
  }
}