/* Personal website: one page, light and dark themes (the system's by default, or the one chosen with the button) */

:root {
  --bg: #f7f8f6;
  --surface: #ffffff;
  --text: #1d2420;
  --muted: #5b665f;
  --border: #dde3de;
  --accent: #2f7d4f;
  --accent-soft: #e4f1e8;
  --shadow: 0 1px 3px rgba(20, 30, 25, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #151a17;
    --surface: #1d2420;
    --text: #e6ebe7;
    --muted: #9faba3;
    --border: #2e3832;
    --accent: #6cc28f;
    --accent-soft: #233229;
    --shadow: none;
  }
}

:root[data-theme="dark"] {
  --bg: #151a17;
  --surface: #1d2420;
  --text: #e6ebe7;
  --muted: #9faba3;
  --border: #2e3832;
  --accent: #6cc28f;
  --accent-soft: #233229;
  --shadow: none;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 4.5rem; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: 960px; margin: 0 auto; padding: 0 16px; }

/* --- top bar --- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}
.topbar .wrap { display: flex; align-items: center; gap: 1rem; min-height: 3.5rem; }
.menu { display: flex; flex-wrap: wrap; gap: 0.25rem 1rem; font-size: 0.95rem; }
.menu a { color: var(--muted); }
.menu a:hover { color: var(--accent); text-decoration: none; }
.theme-button {
  margin-left: auto;
  white-space: nowrap;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  border-radius: 6px;
  padding: 0.2rem 0.55rem;
  cursor: pointer;
  font: inherit;
  font-size: 0.85rem;
}

/* --- sections --- */
section { padding: 3rem 0 1rem; }
h1 { font-size: 2.3rem; line-height: 1.2; margin: 0 0 0.4rem; }
h2 { font-size: 1.45rem; margin: 0 0 1.2rem; padding-bottom: 0.4rem; border-bottom: 2px solid var(--accent-soft); }
h3 { font-size: 1.05rem; margin: 0 0 0.3rem; }
p { margin: 0 0 1rem; }

.intro { padding-top: 4rem; }
.tagline { font-size: 1.2rem; color: var(--muted); margin-bottom: 1.4rem; }
.links { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.links a {
  border: 1px solid var(--border);
  background: var(--surface);
  border-radius: 999px;
  padding: 0.3rem 0.9rem;
  font-size: 0.92rem;
}
.links a:hover { border-color: var(--accent); text-decoration: none; }

.about p { text-align: justify; }

/* --- cards (research themes, software) --- */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1rem; }
.cards.pairs { grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); }
@media (max-width: 420px) { .cards.pairs { grid-template-columns: 1fr; } }
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.1rem 1.2rem;
  box-shadow: var(--shadow);
}
.card p { color: var(--muted); font-size: 0.95rem; margin-bottom: 0.6rem; }
.card .more { font-size: 0.9rem; }
.earlier { color: var(--muted); font-size: 0.95rem; margin-top: 1rem; }

/* --- publications --- */
.filters { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 1.2rem; }
.filters button {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  border-radius: 999px;
  padding: 0.25rem 0.8rem;
  cursor: pointer;
  font: inherit;
  font-size: 0.88rem;
}
.filters button[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: var(--surface); }
.year { font-weight: 600; color: var(--muted); margin: 1.2rem 0 0.4rem; }
.pubs { list-style: none; margin: 0; padding: 0; }
.pubs li { padding: 0.55rem 0; border-bottom: 1px solid var(--border); }
.pubs .title { font-weight: 600; }
.pubs .authors, .pubs .venue { font-size: 0.92rem; color: var(--muted); }
.pubs .venue em { font-style: italic; }
.pubs .me { color: var(--text); font-weight: 600; }
.tag {
  display: inline-block;
  font-size: 0.75rem;
  background: var(--accent-soft);
  color: var(--text);
  border-radius: 4px;
  padding: 0 0.4rem;
  margin-right: 0.3rem;
}

/* --- experience and education --- */
.timeline { list-style: none; margin: 0 0 1.5rem; padding: 0; border-left: 2px solid var(--accent-soft); }
.timeline li { position: relative; padding: 0 0 1.2rem 1.2rem; }
.timeline li::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 0.45rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
}
.when { font-size: 0.88rem; color: var(--muted); }
.timeline p { font-size: 0.95rem; color: var(--muted); margin: 0.2rem 0 0; }

footer { color: var(--muted); font-size: 0.85rem; padding: 2rem 0 3rem; border-top: 1px solid var(--border); margin-top: 2rem; }

@media (max-width: 640px) {
  .topbar .wrap { align-items: flex-start; padding-top: 0.5rem; padding-bottom: 0.5rem; }
  h1 { font-size: 1.8rem; }
  .about p { text-align: left; }
}