:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --text: #141414;
  --muted: #4f4f4f;
  --line: #dfdfdf;
  --link: #0067c5;
  --link-hover: #00488d;
  --header-bg: rgba(255, 255, 255, 0.96);
  --mobile-nav-bg: rgba(255, 255, 255, 0.99);
  --menu-line: #1f1f1f;
  --about-text: #1f1f1f;
  --meta-text: #262626;
  --max-width: 860px;
}

[data-theme="dark"] {
  --bg: #111318;
  --surface: #161a22;
  --text: #eceff7;
  --muted: #a5adbd;
  --line: #30384a;
  --link: #80b9ff;
  --link-hover: #a9d0ff;
  --header-bg: rgba(17, 19, 24, 0.96);
  --mobile-nav-bg: rgba(22, 26, 34, 0.99);
  --menu-line: #eceff7;
  --about-text: #dde3ef;
  --meta-text: #d4daea;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Roboto", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.55;
  padding-top: 66px;
  transition: background-color 0.25s ease, color 0.25s ease;
}

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

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

img {
  display: block;
  max-width: 100%;
}

h1,
h2,
h3 {
  margin: 0;
  font-family: "Noto Serif", Georgia, serif;
  font-weight: 700;
}

h1 {
  font-size: clamp(1.7rem, 3vw, 2rem);
  margin-bottom: 0.65rem;
}

h2 {
  font-size: clamp(1.3rem, 2.3vw, 1.55rem);
  margin-bottom: 0.9rem;
}

p {
  margin: 0;
  padding-bottom: 0.55rem;
  color: var(--text);
}

hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 0;
}

.container {
  width: min(var(--max-width), 92vw);
  margin: 0 auto;
}

.fixed-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
}

.site-header {
  background: var(--header-bg);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(6px);
}

.header-row {
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem;
}

.title-block {
  display: flex;
  align-items: baseline;
  gap: 0.8rem;
  min-width: 0;
}

.brand {
  font-family: "Noto Serif", Georgia, serif;
  font-size: 1.15rem;
  color: var(--text);
  font-weight: 700;
  white-space: nowrap;
}

.subtitle {
  padding-bottom: 0;
  color: var(--muted);
  font-size: 0.87rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.site-nav {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 0.22rem;
}

.site-nav a {
  color: var(--text);
  font-size: 0.93rem;
  font-weight: 600;
  padding: 0.42rem 0.75rem;
  border-radius: 999px;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--link);
}

.menu-toggle {
  display: none;
  border: 0;
  background: transparent;
  padding: 0;
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  margin: 4px 0;
  background: var(--menu-line);
  border-radius: 2px;
}

.theme-toggle {
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--text);
  border-radius: 999px;
  padding: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease, background-color 0.2s ease;
}

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

.theme-toggle .icon {
  width: 18px;
  height: 18px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.theme-toggle .icon-moon path {
  fill: currentColor;
  stroke: none;
}

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

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

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

.main-content {
  padding: 0;
}

.section {
  padding: 1.45rem 0;
}

.about-layout {
  display: grid;
  grid-template-columns: 190px 1fr;
  gap: 1.4rem;
  align-items: start;
}

.photo-wrap {
  width: 100%;
}

.photo-stack {
  width: 100%;
  max-width: 190px;
}

.photo {
  width: 100%;
  max-width: 100%;
  border-radius: 6px;
  border: 1px solid var(--line);
}

.photo-dark {
  display: none;
}

[data-theme="dark"] .photo-light {
  display: none;
}

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

.photo-contact {
  margin-top: 0.7rem;
  display: grid;
  gap: 0.45rem;
}

.photo-contact a {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text);
  font-size: 0.9rem;
  line-height: 1.2;
}

.photo-contact a:hover {
  color: var(--link);
}

.photo-contact .contact-icon {
  width: 16px;
  height: 16px;
  flex: 0 0 16px;
  fill: currentColor;
}

.about-text p {
  color: var(--about-text);
}

.meta-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.2rem;
  margin-top: 0.35rem;
}

.meta-grid h2 {
  font-size: 1.02rem;
  margin-bottom: 0.55rem;
}

.meta-grid p {
  color: var(--meta-text);
  font-size: 0.94rem;
  padding-bottom: 0.4rem;
}

.no-bullet {
  margin: 0;
  padding: 0;
  list-style: none;
}

.entry-list {
  display: grid;
  gap: 0.8rem;
}

.entry-list li {
  margin: 0;
}

.entry-list p {
  padding-bottom: 0.35rem;
}

.jump-link {
  margin-top: 0.6rem;
  font-size: 0.95rem;
}

.cv-viewer {
  width: 100%;
  min-height: 760px;
  border: 1px solid var(--line);
}

.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 0.8rem;
}

.footer-row {
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.7rem;
  flex-wrap: wrap;
}

.footer-row p {
  color: var(--muted);
  font-size: 0.88rem;
  padding-bottom: 0;
}

.page-main {
  padding-top: 1.6rem;
}

.page-intro {
  margin-bottom: 1rem;
}

.paper-grid {
  display: grid;
  gap: 0.7rem;
}

.paper-card,
.project-card,
.timeline article,
.contact-card {
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 0.8rem 0.85rem;
  background: var(--surface);
}

.paper-card h3,
.project-card h2,
.project-card h3 {
  font-size: 1rem;
  margin-bottom: 0.4rem;
}

.authors,
.venue,
.project-meta {
  color: var(--muted);
  font-size: 0.92rem;
}

.paper-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 0.4rem;
  font-size: 0.92rem;
}

.project-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
}

.pub-year {
  margin-bottom: 1rem;
}

.pub-year h2 {
  margin-bottom: 0.7rem;
}

.contact-card p {
  padding-bottom: 0;
}

.reveal {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.4s ease, transform 0.4s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.delay-1 {
  transition-delay: 0.08s;
}

.delay-2 {
  transition-delay: 0.16s;
}

@media (max-width: 880px) {
  .subtitle {
    display: none;
  }

  .meta-grid {
    grid-template-columns: 1fr;
    gap: 0.8rem;
  }

  .about-layout {
    grid-template-columns: 160px 1fr;
    gap: 1rem;
  }

  .photo {
    max-width: 160px;
  }
}

@media (max-width: 760px) {
  body {
    padding-top: 60px;
  }

  .header-row {
    min-height: 60px;
  }

  .menu-toggle {
    display: inline-block;
  }

  .site-nav {
    position: absolute;
    top: 60px;
    right: 4vw;
    left: 4vw;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--mobile-nav-bg);
    padding: 0.45rem;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .site-nav a {
    padding: 0.55rem 0.65rem;
    border-radius: 6px;
  }

  .site-nav.open {
    display: flex;
  }

  .about-layout {
    grid-template-columns: 1fr;
  }

  .photo-wrap {
    width: 150px;
  }

  .cv-viewer {
    min-height: 520px;
  }
}