:root {
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-muted: #5f6368;
  --color-border: #e6e8eb;
  --color-accent: #1a1a1a;
  --color-hover: #f5f6f8;

  --sidebar-width: 220px;
  --topbar-height: 64px;
  --content-max-width: 630px;

  --font-sans: "Merriweather", Georgia, "Times New Roman", serif;
}

[data-theme="dark"] {
  --color-bg: #0f1115;
  --color-text: #e8e8e8;
  --color-muted: #9aa0a6;
  --color-border: #2a2e34;
  --color-hover: #1c1f25;
}

[data-theme="dark"] .topbar {
  background: rgba(15, 17, 21, 0.85);
}

[data-theme="dark"] .topbar__nav a:hover,
[data-theme="dark"] .topbar__nav a:focus-visible,
[data-theme="dark"] .theme-toggle:hover,
[data-theme="dark"] .theme-toggle:focus-visible {
  color: #fff;
}

[data-theme="dark"] .sidebar__photo {
  background: #1c1f25;
}

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

html,
body {
  margin: 0;
  padding: 0;
}

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-optical-sizing: auto;
  font-weight: 400;
  font-style: normal;
  font-size: 14px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
}

/* Top bar */
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  height: var(--topbar-height);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(8px);
  -webkit-backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.topbar__nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 2rem;
  height: 100%;
  max-width: 800px;
  margin: 0 auto;
  padding: 0 2rem;
}

.topbar__nav a {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--color-text);
  transition: color 0.15s ease;
}

.topbar__nav a:hover,
.topbar__nav a:focus-visible {
  color: #000;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  background: transparent;
  border: 0;
  padding: 0.25rem;
  margin: 0;
  cursor: pointer;
  color: var(--color-text);
  transition: color 0.15s ease;
}

.theme-toggle:hover,
.theme-toggle:focus-visible {
  color: #000;
}

.theme-toggle__icon {
  display: block;
}

.theme-toggle__icon--sun {
  display: none;
}

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

[data-theme="dark"] .theme-toggle__icon--sun {
  display: block;
}

/* Layout */
.layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  gap: 0.5rem;
  max-width: 1000px;
  margin: 0 auto;
  padding: 3rem 2rem 5rem;
}

/* Sidebar */
.sidebar {
  position: sticky;
  top: calc(var(--topbar-height) + 2rem);
  align-self: start;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.sidebar__photo {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid var(--color-border);
  background: #f0f2f5;
}

.sidebar__name {
  margin: 1.25rem 0 1.5rem;
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.links {
  list-style: none;
  margin: 0;
  padding: 0;
  width: 100%;
}

.links li + li {
  margin-top: 0.25rem;
}

.link {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  padding: 0.5rem 0.6rem;
  border-radius: 6px;
  font-size: 0.8rem;
  color: var(--color-text);
  transition: background-color 0.15s ease;
}

.link:hover,
.link:focus-visible {
  background: var(--color-hover);
}

.link__icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  fill: currentColor;
}

/* Main content */
.content {
  max-width: var(--content-max-width);
}

.section {
  scroll-margin-top: calc(var(--topbar-height) + 1rem);
  padding-bottom: 2rem;
}

.section + .section {
  padding-top: 1rem;
}

.section__title {
  margin: 0 0 1rem;
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.section p {
  margin: 0;
}

.section p a,
.news__item a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* News */
.news {
  list-style: none;
  margin: 0;
  padding: 0;
}

.news__item + .news__item {
  margin-top: 0.5rem;
}

.news__date {
  font-weight: 700;
  margin-right: 0.4rem;
}

/* Papers */
.papers {
  list-style: none;
  margin: 0;
  padding: 0;
}

.paper + .paper {
  margin-top: 1.25rem;
}

.paper__title {
  font-weight: 600;
}

.paper__authors {
  margin-top: 0.2rem;
  color: var(--color-muted);
}

.paper__venue {
  margin-top: 0.2rem;
  font-style: italic;
  color: var(--color-muted);
}

.paper__links {
  margin-top: 0.25rem;
}

.paper__links a {
  text-decoration: underline;
  margin-right: 0.5rem;
}

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

.paper__abstract-toggle {
  background: none;
  border: 0;
  padding: 0;
  margin: 0;
  font: inherit;
  color: inherit;
  cursor: pointer;
  text-decoration: underline;
}

.paper__abstract-toggle:hover {
  color: var(--color-muted);
}

.paper__abstract {
  font-size: 13px;
  margin-top: 0.5rem;
  text-align: justify;
}

.paper__abstract p {
  margin: 0;
}

/* Responsive */
@media (max-width: 820px) {
  .layout {
    grid-template-columns: 1fr;
    gap: 2.5rem;
    padding: 2rem 1.25rem 3rem;
  }

  .sidebar {
    position: static;
    align-items: center;
    text-align: center;
  }

  .links {
    max-width: 280px;
  }

  .topbar__nav {
    justify-content: center;
    padding: 0 1.25rem;
    gap: 1.5rem;
  }
}