:root {
  --bg: #ffffff;
  --bg-soft: #f5f7fa;
  --text: #1d2430;
  --muted: #5b6577;
  --accent: #1f4e79;
  --accent-soft: #e6eef6;
  --border: #e2e6ec;
  --notice-bg: #fff8e6;
  --notice-border: #f0c75e;
  --serif: Georgia, "Iowan Old Style", "Palatino Linotype", "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* Dark theme is the default (set on <html data-theme="dark">); the toggle switches to light. */
:root[data-theme="dark"] {
  --bg: #12161c; --bg-soft: #1a2029; --text: #e3e7ee; --muted: #9aa4b5;
  --accent: #8cb8e8; --accent-soft: #1f2d3d; --border: #2a3240;
  --notice-bg: #2a2416; --notice-border: #8a6d2a;
  color-scheme: dark;
}
:root[data-theme="light"] { color-scheme: light; }

/* Theme toggle */
.theme-toggle {
  flex: none; margin-left: auto;
  width: 36px; height: 36px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  background: var(--bg-soft); color: var(--text);
  border: 1px solid var(--border); cursor: pointer;
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); }
.theme-toggle:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.theme-toggle svg { width: 20px; height: 20px; }
.theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-sun { display: block; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: none; }

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 16px; background: var(--bg); padding: 8px 12px; z-index: 10; }

.layout {
  max-width: 1080px;
  margin: 0 auto;
  padding: 32px 24px 48px;
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 56px;
}

/* Mobile menu + drawer (hidden on desktop) */
.menu-btn, .drawer, .drawer-backdrop { display: none; }
.menu-btn, .drawer-close {
  width: 42px; height: 42px; border-radius: 50%;
  align-items: center; justify-content: center;
  background: var(--bg-soft); color: var(--text);
  border: 1px solid var(--border); cursor: pointer;
}
.menu-btn svg, .drawer-close svg { width: 22px; height: 22px; }
.menu-btn:focus-visible, .drawer-close:focus-visible, .drawer-nav a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* Sidebar */
/* Fixed in place: sticks exactly where it starts (57px top bar + 32px padding) and never scrolls.
   The map flexes to fill whatever height is left; on very short windows the sidebar scrolls internally. */
.sidebar {
  position: sticky; top: 89px; align-self: start;
  max-height: calc(100vh - 105px);
  display: flex; flex-direction: column;
  overflow-y: auto; scrollbar-width: none;
}
.sidebar::-webkit-scrollbar { display: none; }
.sidebar > * { flex: none; }
/* Everything in the sidebar shares one centre line: photo, text, links, clock and map */
.sidebar { text-align: center; }
/* Photo spans the full sidebar width, matching the map; on shorter windows it becomes a wider, cropped frame instead of shrinking */
.sidebar .avatar {
  /* Portrait photo: takes the space left over (up to 260x325) and shrinks first on short windows */
  align-self: center; aspect-ratio: 4 / 5; width: auto; height: auto; max-width: 100%;
  flex: 0 1 325px; min-height: 140px; object-position: 50% 30%;
}
.sidebar .links { display: flex; flex-direction: column; align-items: center; }
.avatar {
  width: 240px; height: 240px; border-radius: 6px;
  object-fit: cover; display: block; margin-bottom: 18px;
}
.avatar-placeholder {
  display: flex; align-items: center; justify-content: center;
  background: var(--accent-soft); color: var(--accent);
  font-family: var(--serif); font-size: 56px; letter-spacing: 2px;
}
.name { font-family: var(--serif); font-size: 30px; font-weight: 600; margin: 0 0 6px; line-height: 1.2; }
.role { margin: 0 0 10px; font-weight: 500; }
.affil, .loc { margin: 0 0 8px; color: var(--muted); font-size: 14.5px; }
.links { list-style: none; padding: 0; margin: 18px 0; font-size: 14.5px; }
.links li { margin: 4px 0; overflow-wrap: anywhere; }
/* Top navigation bar */
.topbar {
  position: sticky; top: 0; z-index: 30;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}
.topbar-inner {
  max-width: 1080px; margin: 0 auto; padding: 0 24px;
  height: 56px; display: flex; align-items: center; gap: 16px;
}
.toc {
  display: flex; gap: 22px; overflow-x: auto; white-space: nowrap;
  font-size: 14.5px; scrollbar-width: none;
}
.toc::-webkit-scrollbar { display: none; }
.toc a { color: var(--muted); padding: 6px 0; border-bottom: 2px solid transparent; }
.toc a:hover { color: var(--accent); text-decoration: none; border-bottom-color: var(--accent); }

/* Location map */
.sidebar > .map { flex: none; }
.map { margin-top: 18px; }
.sidebar > .map iframe { height: 120px; }
.map iframe {
  display: block; width: 100%; height: 170px; border: 1px solid var(--border); border-radius: 6px;
}
:root[data-theme="dark"] .map iframe { filter: invert(90%) hue-rotate(180deg) brightness(.95) contrast(.9); }
.clock {
  display: flex; align-items: center; justify-content: center; gap: 6px; flex-wrap: wrap;
  margin: 4px 0 0; font-size: 14px; text-align: center;
}
.clock svg { width: 16px; height: 16px; color: var(--accent); flex: none; }
.clock-time { font-weight: 600; font-variant-numeric: tabular-nums; }
.clock-zone { color: var(--muted); font-size: 13px; }
.map-link { display: block; margin-top: 6px; font-size: 13px; color: var(--muted); }

/* Desktop: GitHub | LinkedIn | IEEE Xplore on one line at the bottom of the sidebar */
.links .social-item { display: none; }
.social-line { margin: -12px 0 14px; font-size: 14.5px; white-space: nowrap; }
.social-line .sep { color: var(--muted); margin: 0 6px; }

/* Main */
main { min-width: 0; }
.notice {
  background: var(--notice-bg);
  border-left: 4px solid var(--notice-border);
  padding: 12px 16px; border-radius: 4px; margin-bottom: 32px; font-size: 15px;
}
section { margin-bottom: 40px; scroll-margin-top: 76px; }
h2 {
  font-family: var(--serif); font-size: 23px; font-weight: 600;
  margin: 0 0 14px; padding-bottom: 6px; border-bottom: 1px solid var(--border);
}
h3 { font-size: 16.5px; margin: 0; font-weight: 600; }
.muted { color: var(--muted); font-size: 14.5px; }

.tags { list-style: none; padding: 0; margin: 0 0 14px; display: flex; flex-wrap: wrap; gap: 8px; }
.tags li { background: var(--accent-soft); color: var(--accent); padding: 4px 12px; border-radius: 999px; font-size: 14px; }

.news { list-style: none; padding: 0; margin: 0; }
.news li { display: grid; grid-template-columns: 84px 1fr; gap: 12px; padding: 5px 0; }
.date { color: var(--muted); font-variant-numeric: tabular-nums; font-size: 14.5px; }

.pubs { padding-left: 22px; margin: 0 0 12px; }
.pubs li { margin-bottom: 12px; }
.pubs li span { display: block; }
.pubs .title { font-weight: 600; }
.pub-links a { margin-right: 8px; font-size: 14.5px; }

.project { margin-bottom: 20px; }
.project p { margin: 6px 0; }
.when { color: var(--muted); font-weight: 400; font-size: 14px; white-space: nowrap; }
.project h3 .when { margin-left: 6px; }

.entry { margin-bottom: 20px; }
.entry-head { display: flex; justify-content: space-between; gap: 12px; align-items: baseline; flex-wrap: wrap; }
.org { margin: 2px 0 6px; color: var(--muted); font-size: 15px; }
.entry ul, section > ul { margin: 6px 0; padding-left: 20px; }
.entry li, section > ul li { margin: 4px 0; }

.skills { display: grid; grid-template-columns: 170px 1fr; gap: 6px 16px; margin: 0; }
.skills dt { font-weight: 600; }
.skills dd { margin: 0; }

footer { border-top: 1px solid var(--border); padding-top: 14px; color: var(--muted); font-size: 13.5px; }

/* Shorter desktop windows: compact the fixed sidebar so it fits without moving */
@media (min-width: 821px) and (max-height: 980px) {
  .name { font-size: 24px; margin-bottom: 4px; }
  .role, .affil, .loc { margin-bottom: 4px; font-size: 13.5px; }
  .links { margin: 8px 0; font-size: 13.5px; }
  .links li { margin: 2px 0; }
  .social-line { margin: -4px 0 8px; font-size: 13.5px; }
  .map { margin-top: 10px; }
  .map-link { display: none; }
}

@media (min-width: 821px) and (max-height: 680px) {
  .name { font-size: 22px; }
  .role, .affil, .loc { font-size: 13px; margin-bottom: 2px; }
  .links { margin: 6px 0; }
  .clock { font-size: 13px; }
  .sidebar .avatar { min-height: 80px; }
  .sidebar > .map iframe { height: 90px; }
}

/* Mobile */
@media (max-width: 820px) {
  .layout { grid-template-columns: 1fr; gap: 24px; padding: 28px 16px; }
  .sidebar { position: static; text-align: center; display: block; max-height: none; overflow: visible; }
  .sidebar .avatar { margin: 0 auto 14px; width: 200px; height: 250px; aspect-ratio: auto; }
  .sidebar .links { flex-direction: row; flex-wrap: wrap; justify-content: center; gap: 4px 14px; }
  .sidebar .map { display: none; }
  .links .social-item { display: list-item; }
  .social-line { display: none; }
  .drawer .map { margin-top: 16px; }
  .drawer .map iframe { height: 112px; }
  .avatar-placeholder { font-size: 44px; }
  .links { display: flex; flex-wrap: wrap; justify-content: center; gap: 4px 14px; }
  .topbar { display: none; }
  .menu-btn {
    display: flex; position: fixed; top: 12px; right: 12px; z-index: 40;
    box-shadow: 0 2px 8px rgba(0,0,0,.25);
  }
  .drawer-backdrop {
    display: block; position: fixed; inset: 0; z-index: 50;
    background: rgba(0,0,0,.5); opacity: 0; visibility: hidden;
    transition: opacity .2s ease, visibility .2s ease;
  }
  .drawer {
    display: flex; flex-direction: column; gap: 8px;
    position: fixed; top: 0; right: 0; bottom: 0; z-index: 60;
    width: min(300px, 82vw); padding: 16px 20px 24px;
    background: var(--bg); border-left: 1px solid var(--border);
    transform: translateX(100%); visibility: hidden;
    transition: transform .25s ease, visibility .25s ease;
    overflow-y: auto;
  }
  .drawer-open .drawer { transform: translateX(0); visibility: visible; }
  .drawer-open .drawer-backdrop { opacity: 1; visibility: visible; }
  .drawer-open { overflow: hidden; }
  .drawer-head { display: flex; align-items: center; justify-content: space-between; padding-bottom: 12px; border-bottom: 1px solid var(--border); }
  .drawer-title { font-family: var(--serif); font-size: 19px; font-weight: 600; }
  .drawer-close { display: flex; }
  .drawer-nav { display: flex; flex-direction: column; padding: 6px 0; }
  .drawer-nav a { color: var(--text); padding: 9px 4px; border-bottom: 1px solid var(--border); font-size: 16px; }
  .drawer-nav a:hover { color: var(--accent); text-decoration: none; }
  .drawer-theme {
    display: flex; gap: 10px; width: auto; height: 44px; border-radius: 8px;
    margin: 8px 0 0; padding: 0 14px; justify-content: flex-start; font: inherit; font-size: 15px;
  }
  section { scroll-margin-top: 16px; }
  .skills { grid-template-columns: 1fr; gap: 0; }
  .skills dd { margin-bottom: 10px; }
  .news li { grid-template-columns: 1fr; gap: 0; }
}

@media print {
  .topbar, .notice, .skip, .menu-btn, .drawer, .drawer-backdrop { display: none !important; }
  .layout { display: block; padding: 0; }
  .sidebar { position: static; }
}