:root {
  --bg: #ffffff;          
  --text: #1a1a1a;        
  --muted: #666666;       
  --border: #e6e3db;      

  --heading: #1a1a1a;     
  --link: #2b4fdb;       
  --accent: #2b4fdb;      

  --maxw: 46rem;
  --sans: "Ubuntu", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

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

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.15s ease;
}
a:hover {
  text-decoration: underline;
  text-decoration-color: var(--accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}
a:active { color: var(--accent); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }

/* Top */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border-top: 3px solid var(--accent);
  border-bottom: 1px solid var(--border);
}
.nav {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0.8rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
  flex-wrap: wrap;
}
.nav__brand { display: block; text-decoration: none; }
.nav__brand:hover { text-decoration: none; }
.nav__name {
  display: block;
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  line-height: 1.25;
}
.nav__role {
  display: block;
  margin-top: 0.1rem;
  font-size: 0.8rem;
  color: var(--muted);
}
.nav__links { display: flex; flex-wrap: wrap; gap: 1.1rem; margin: 0; padding: 0; list-style: none; }
.nav__links a { color: var(--muted); font-size: 0.95rem; }
.nav__links a:hover { color: var(--text); text-decoration: none; }
.nav__links a:active { color: var(--accent); }
.nav__links a.is-current { color: var(--accent); }

/* Layout */
main { max-width: var(--maxw); margin: 0 auto; padding: 0 1.25rem 4rem; }

/* accent colour */
.highlight { color: var(--accent); font-weight: 500; }
.coming { color: var(--muted); font-style: italic; }

/* sections */
.section { padding-top: 2.75rem; scroll-margin-top: 5.5rem; }
.section h2 {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--heading);
  margin: 0 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border);
}
.subhead { font-size: 1.15rem; font-weight: 500; color: var(--heading); margin: 2rem 0 0.9rem; }
.section p { text-align: justify; -webkit-hyphens: auto; hyphens: auto; }

/* papers */
.papers { margin: 0; padding: 0; list-style: none; }
.paper { margin-bottom: 1.3rem; }
.paper > span { display: block; }
.paper__title { font-weight: 500; }
.paper__meta { color: var(--muted); font-size: 0.97rem; }
.paper__links { font-size: 0.9rem; margin-top: 0.15rem; }

/* project write-ups */
.project { margin-bottom: 1.4rem; }
.project__title { margin: 0 0 0.3rem; font-size: 1.1rem; font-weight: 500; color: var(--heading); }
.project p { margin: 0; }

/* teaching */
.teaching { margin: 0; padding: 0; list-style: none; }
.teaching li { margin-bottom: 0.75rem; }

/* footer */
.site-footer { border-top: 1px solid var(--border); padding: 1.6rem 1.25rem; text-align: center; color: var(--muted); font-size: 0.9rem; }

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

/* font stuffs */
@font-face {
  font-family: "Ubuntu"; font-style: normal; font-weight: 400; font-display: swap;
  src: url("ubuntu-400.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: "Ubuntu"; font-style: normal; font-weight: 400; font-display: swap;
  src: url("ubuntu-ext-400.woff2") format("woff2");
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: "Ubuntu"; font-style: normal; font-weight: 500; font-display: swap;
  src: url("ubuntu-500.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: "Ubuntu"; font-style: normal; font-weight: 500; font-display: swap;
  src: url("ubuntu-ext-500.woff2") format("woff2");
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: "Ubuntu"; font-style: normal; font-weight: 700; font-display: swap;
  src: url("ubuntu-700.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: "Ubuntu"; font-style: normal; font-weight: 700; font-display: swap;
  src: url("ubuntu-ext-700.woff2") format("woff2");
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
@font-face {
  font-family: "Ubuntu"; font-style: italic; font-weight: 400; font-display: swap;
  src: url("ubuntu-400i.woff2") format("woff2");
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: "Ubuntu"; font-style: italic; font-weight: 400; font-display: swap;
  src: url("ubuntu-ext-400i.woff2") format("woff2");
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}