:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --muted: #666;
  --accent: #51247a;
  --accent-dark: #3b1a59;
  --accent-soft: #f5f0fa;
  --border: #e5e5e5;
  color-scheme: light;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  line-height: 1.6;
  background: var(--bg);
  color: var(--text);
}
.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px; }

header { border-top: 4px solid var(--accent); border-bottom: 1px solid var(--border); }
header .wrap {
  display: flex; flex-wrap: wrap; align-items: center;
  justify-content: space-between; gap: 8px; padding-top: 12px; padding-bottom: 12px;
}
.brand { margin-right: auto; font-weight: 700; font-size: 1.25rem; color: var(--accent); text-decoration: none; }
nav { display: flex; flex-wrap: wrap; gap: 2px; }
nav a {
  color: var(--text); text-decoration: none;
  padding: 10px 12px; border-radius: 6px;
}
nav a:hover { background: var(--accent-soft); }
nav a[aria-current="page"] { color: var(--accent); background: var(--accent-soft); font-weight: 600; }

main.wrap { padding-top: 32px; padding-bottom: 48px; }
main a:not(.btn) { color: var(--accent); }
h1 { font-family: Georgia, "Times New Roman", serif; font-size: 2rem; line-height: 1.2; margin: 0 0 16px; }
footer { border-top: 1px solid var(--border); background: var(--accent-soft); color: var(--muted); font-size: .9rem; padding: 16px 0; }
@media (max-width: 480px) {
  header .wrap { flex-direction: column; align-items: flex-start; gap: 0; }
  nav { margin-left: -12px; }
}

[hidden] { display: none !important; }
h2 { font-family: Georgia, "Times New Roman", serif; font-size: 1.4rem; margin: 32px 0 16px; }
.muted { color: var(--muted); }

/* Members */
.people {
  list-style: none; margin: 0; padding: 0;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px 16px;
}
.person { text-align: center; font-size: .9rem; }
.avatar {
  display: block; width: 140px; height: 140px; margin: 0 auto 10px;
  border-radius: 50%; object-fit: cover; background: var(--border);
}
.avatar-empty { display: grid; place-items: center; }
.avatar-empty svg { width: 60%; height: 60%; fill: #c4c4c4; }
.person-name { font-weight: 600; font-size: 1rem; }
.person-name a { color: var(--accent); }
.person-role { color: var(--accent); }
.person-meta { color: var(--muted); font-style: italic; }
.projects { padding-left: 20px; }
.projects li { margin-bottom: 6px; }
@media (max-width: 640px) {
  .people { grid-template-columns: repeat(2, 1fr); }
  .avatar { width: 110px; height: 110px; }
}

/* Research */
.research-page .wrap { max-width: 1240px; }
.filters { display: grid; gap: 12px; margin-bottom: 8px; }
#search {
  width: 100%; padding: 10px 12px; font: inherit;
  border: 1px solid var(--border); border-radius: 6px; background: var(--bg); color: var(--text);
}
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  font: inherit; font-size: .95rem; padding: 8px 14px; cursor: pointer;
  border: 1px solid var(--border); border-radius: 999px; background: var(--bg); color: var(--text);
}
.chip:hover { border-color: var(--accent); }
.chip[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: #fff; }
.filter-status { font-size: .9rem; }
button.link { font: inherit; border: 0; background: none; padding: 0; color: var(--accent); cursor: pointer; text-decoration: underline; }
.pubs { list-style: none; margin: 0; padding: 0; display: grid; gap: 32px; }
.pub { display: flex; gap: 32px; align-items: flex-start; }
.thumb { flex: 0 0 400px; width: 400px; height: 250px; border-radius: 8px; object-fit: contain; background: var(--accent-soft); }
.pub-body { min-width: 0; }
.pub-title { font-weight: 600; font-size: 1.4rem; line-height: 1.45; }
.pub-authors { font-size: 1.1rem; margin-top: 8px; }
.pub-venue { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-top: 8px; font-size: .9rem; }
.venue { font-weight: 700; color: var(--accent); margin-right: 4px; }
.tag { padding: 1px 8px; border-radius: 999px; background: var(--border); color: var(--muted); }
.pub-links { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 8px; }
.btn {
  font: inherit; font-size: .8rem; padding: 3px 10px; cursor: pointer; text-decoration: none;
  border: 1px solid var(--accent); border-radius: 4px; background: none; color: var(--accent);
}
.btn:hover { background: var(--accent); color: #fff; }
.pub-links .btn { font-size: 1rem; padding: 9px 16px; }
.bibtex { font-size: .75rem; background: var(--border); padding: 10px; border-radius: 6px; overflow-x: auto; white-space: pre; }

@media (max-width: 960px) {
  .pub { flex-direction: column; }
  .thumb { width: 100%; height: auto; aspect-ratio: 8 / 5; flex-basis: auto; }
}
.pager { display: flex; flex-wrap: wrap; justify-content: center; gap: 6px; margin-top: 32px; }
.page-btn {
  font: inherit; font-size: .9rem; min-width: 40px; padding: 6px 10px; cursor: pointer;
  border: 1px solid var(--border); border-radius: 6px; background: var(--bg); color: var(--text);
}
.page-btn:hover:not(:disabled) { border-color: var(--accent); }
.page-btn[aria-current="page"] { background: var(--accent); border-color: var(--accent); color: #fff; }
.page-btn:disabled { opacity: .4; cursor: default; }

/* Home */
.hero {
  padding: clamp(24px, 5vw, 40px); margin-bottom: 28px; border-radius: 12px;
  background: var(--accent); color: #fff;
}
.eyebrow { margin: 0 0 16px; font-size: .8rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; }
.hero h1 { font-size: clamp(2.5rem, 7vw, 3.5rem); margin-bottom: 12px; }
.slogan { margin: 0 0 24px; font-size: clamp(1.2rem, 4vw, 1.65rem); line-height: 1.4; }
.affiliation { margin: 0; font-size: .9rem; }
.hero .affiliation a { color: #fff; text-underline-offset: 4px; }
.hero .affiliation a:hover { text-decoration-thickness: 2px; }
.lead { font-size: 1.15rem; }
.areas { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.areas li { border: 1px solid var(--border); border-top: 3px solid var(--accent); background: var(--accent-soft); border-radius: 8px; padding: 14px 16px; }
.areas strong { display: block; color: var(--accent); }
.areas span { color: var(--muted); font-size: .9rem; }
.cta { margin-top: 28px; display: flex; flex-wrap: wrap; gap: 8px; }
.cta .btn { font-size: .95rem; padding: 8px 16px; }
.cta .btn:first-child { background: var(--accent); color: #fff; }
.cta .btn:first-child:hover { background: var(--accent-dark); }
@media (max-width: 640px) { .areas { grid-template-columns: 1fr; } }

/* Qiuqiu */
.robot-figure { margin: 28px 0; }
.robot-figure img { display: block; width: 100%; height: auto; border-radius: 12px; }
.robot-figure figcaption { margin-top: 10px; color: var(--muted); font-size: .9rem; }
.qiuqiu-project { margin-top: 24px; padding: clamp(18px, 4vw, 28px); border: 1px solid var(--border); border-top: 3px solid var(--accent); border-radius: 10px; }
.qiuqiu-project h3 { margin: 8px 0 16px; color: var(--accent); font-size: 1.35rem; line-height: 1.35; }
.qiuqiu-project p:last-child { margin-bottom: 0; }
.project-category { margin: 0; color: var(--muted); font-size: .85rem; }
.project-figure { margin: 20px 0; }
.project-figure img { max-width: 596px; margin: 0 auto; }