/* Minimal academic theme with modern touches and dark-mode */
/* System font stack for readability */
:root {
  --bg: #ffffff;
  --text: #111111;
  --muted: #5f6368;
  --accent: #155eef;
  --accent-weak: #e7efff;
  --border: #e5e7eb;
  --code-bg: #f6f8fa;
  --card: #ffffff;
  --shadow: 0 1px 2px rgba(0,0,0,.05), 0 8px 24px rgba(0,0,0,.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0f14;
    --text: #e6e6e6;
    --muted: #a0a3a8;
    --accent: #70a0ff;
    --accent-weak: #11213f;
    --border: #1e2937;
    --code-bg: #0f1720;
    --card: #0f141b;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.35);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
}

.container { width: 100%; max-width: 960px; margin: 0 auto; padding: 0 20px; }

/* Header and nav */
header.site-header {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: saturate(180%) blur(10px);
  background: color-mix(in oklab, var(--bg) 80%, transparent);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; padding: 10px 0; }
.brand { display: flex; align-items: baseline; gap: 10px; }
.brand h1 { font-size: 18px; margin: 0; font-weight: 650; letter-spacing: .2px; }
.brand .subtitle { color: var(--muted); font-size: 13px; }
.brand .logo { height: 22px; width: auto; opacity: 0.9; }
.brand .logo-badge { display: inline-flex; align-items: center; justify-content: center; padding: 4px 8px; border-radius: 8px; background: #0b1220; border: 1px solid #111827; }
.nav a { color: var(--muted); text-decoration: none; margin-left: 18px; font-size: 14px; }
.nav a:hover, .nav a:focus, .nav a.active { color: var(--text); }
.nav a.active { text-decoration: underline; text-underline-offset: 4px; }

/* Hero */
.hero { padding: 72px 0 56px; position: relative; background: url('images/Singapore.webp') center/cover no-repeat; }
.hero::before { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(0,0,0,.62) 0%, rgba(0,0,0,.46) 35%, rgba(0,0,0,.24) 65%, rgba(0,0,0,.08) 85%, rgba(0,0,0,0) 100%); }
.hero::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(128,128,128,.22) 0%, rgba(128,128,128,0) 70%); }
.hero > .container { position: relative; z-index: 1; }
.title { font-size: 34px; line-height: 1.2; margin: 0 0 8px; font-weight: 700; }
.hero .title { color: #ffffff; text-shadow: 0 2px 6px rgba(0,0,0,.35); }
.authors, .affiliations { color: #e5e7eb; margin: 4px 0; text-shadow: 0 1px 2px rgba(0,0,0,.35); }
.actions { display: flex; gap: 10px; margin-top: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 12px; border-radius: 10px;
  border: 1px solid var(--border); background: var(--card);
  color: var(--text); text-decoration: none; box-shadow: var(--shadow);
}
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.ghost { background: transparent; }

/* Sections */
section { padding: 28px 0; border-top: 1px solid var(--border); }
section:first-of-type { border-top: 0; }
section h2 { margin: 0 0 8px; font-size: 22px; }
section h3 { margin: 16px 0 8px; font-size: 18px; }
section p { margin: 8px 0; }
section ul { margin: 8px 0 8px 18px; }

/* Article elements */
.abstract { background: var(--accent-weak); padding: 14px 16px; border-radius: 12px; border: 1px solid var(--border); }
code, pre { background: var(--code-bg); border-radius: 8px; }
pre { padding: 12px; overflow: auto; }

/* Figures and table */
figure { margin: 16px 0; }
figure img { width: 100%; height: auto; border-radius: 10px; border: 1px solid var(--border); }
figure figcaption { color: var(--muted); font-size: 13px; margin-top: 6px; }

.people-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px; margin: 12px 0 8px;
}
.presenter { display: grid; grid-template-columns: 160px 1fr; gap: 16px; padding: 16px 0; border-top: 1px solid var(--border); }
.presenter:first-of-type { border-top: 0; }
.presenter .photo { width: 160px; height: 160px; border-radius: 12px; object-fit: cover; border: 1px solid var(--border); background: var(--code-bg); }
.presenter .content h3 { margin: 0 0 6px; }
.presenter .content p { margin: 0; }

@media (max-width: 720px) {
  .presenter { grid-template-columns: 1fr; }
  .presenter .photo { width: 100%; height: auto; max-height: 280px; }
}
.person { display: flex; align-items: center; gap: 12px; padding: 10px; border: 1px solid var(--border); border-radius: 12px; background: var(--card); box-shadow: var(--shadow); }
.person img, .avatar-fallback { width: 64px; height: 64px; border-radius: 50%; object-fit: cover; border: 1px solid var(--border); background: var(--code-bg); }
.avatar-fallback { display: inline-flex; align-items: center; justify-content: center; font-weight: 700; color: var(--muted); }
.person .meta { display: flex; flex-direction: column; }
.person .name { font-weight: 650; }
.person .affil { color: var(--muted); font-size: 13px; }

.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: 12px; }
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { padding: 10px 12px; border-bottom: 1px solid var(--border); vertical-align: top; }
thead th { text-align: left; font-weight: 650; background: color-mix(in oklab, var(--accent-weak) 70%, transparent); }
tbody tr:last-child td { border-bottom: 0; }

/* Footer */
footer { color: var(--muted); padding: 32px 0 40px; text-align: center; }

/* Back to top */
.to-top { position: fixed; right: 20px; bottom: 20px; display: none; }
.to-top.show { display: inline-flex; }

/* Small screens */
@media (max-width: 720px) {
  .title { font-size: 26px; }
  .nav a { margin-left: 12px; }
}