/* ====== Base ====== */
:root {
  --content-max: 1100px;        /* <<< change this one value to widen/narrow the whole site */
  --bg: #0b0e14;
  --panel: #121826;
  --text: #e5e7eb;
  --muted: #9aa4b2;
  --brand: #5da7ff;
  --brand-2: #9bffd6;
  --card: #0f1422;
  --border: #22304b;
  --shadow: 0 10px 25px rgba(0,0,0,.35);
  --headerbrand: #5da7ff;
  --headerbrand-2: #9bffd6;
  --hero-card-1: #1d2740;
  --hero-card-2: #0f1422;
  --button-bg: #5da7ff;
  --button-fg: #04070f;
  --button-border: #6ab1ff;
  color-scheme: dark;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body { background: var(--bg); color: var(--text); line-height: 1.6; }

.container { max-width: var(--content-max); margin: 0 auto; padding: 0 20px; }

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

.skip-link { position: absolute; left: -999px; top: -999px; }
.skip-link:focus { left: 12px; top: 12px; background:#fff; color:#000; padding:.5rem .75rem; border-radius:8px; }

/* ====== Header / Banner ====== */
.nav { white-space: nowrap; flex-shrink: 0; }

.site-header.banner {
  background: linear-gradient(90deg, var(--headerbrand), var(--headerbrand-2));
  color: #04070f;
  text-align: center;
  padding: 2px 0;
  position: sticky; top: 0; z-index: 50;
}

.banner .site-title { margin: 0; font-size: clamp(24px, 3vw, 34px); font-weight: 800; color: #04070f; }
.banner .site-subtitle { margin: 4px 0 16px; color: #04070f; font-weight: 500; }

.banner .nav a {
  color: #04070f; font-weight: 600; margin: 0 10px; padding: 8px 12px;
  border-radius: 8px; border: 1px solid transparent;
}
.banner .nav a:hover { background: rgba(255,255,255,0.2); border-color: #04070f; text-decoration: none; }

.site-header { position: sticky; top: 0; z-index: 50; }
.header-inner { flex-wrap: nowrap; display: flex; gap: 24px; align-items: center; justify-content: space-between; padding: 5px 0; }
.site-title { white-space: nowrap; margin: 0; font-size: clamp(20px, 3vw, 28px); letter-spacing: .2px; }
.site-subtitle { margin: 4px 0 0; color: var(--muted); font-size: 0.95rem; }

.nav a { margin-left: 14px; padding: 8px 10px; border-radius: 10px; border: 1px solid transparent; }
.nav a:hover { background: var(--panel); border-color: var(--border); text-decoration: none; }

/* ====== Hero ====== */
.hero { padding: 40px 0 20px; }

.hero-inner {
  display: grid;
  grid-template-columns: 0.41fr 1.5fr 0.7fr;   /* Photo | Bio | Stats */
  gap: 40px;
  align-items: stretch;
}

/* Photo + contact (left column) */
.hero-photo { display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: left; }
.hero-photo img {
  width: 150px; height: 150px; object-fit: cover; border-radius: 50%;
  border: none; box-shadow: var(--shadow); margin-bottom: 1px;
}
.hero-contact { font-size: 0.95rem; color: var(--muted); line-height: 1.4; }
.hero-contact a { color: var(--brand); text-decoration: none; }
.hero-contact a:hover { text-decoration: underline; }

/* Bio text (middle column) */
.hero-text h2 { font-size: clamp(28px, 4vw, 44px); margin: 0 0 8px; line-height: 1.15; }
.hero-text p { color: var(--muted); margin: 0 0 18px; }

/* CTA buttons */
.cta-row { display: flex; gap: 12px; }
.button {
  border: 1px solid var(--button-border);
  display: inline-block; padding: 8px 12px; background: var(--brand); color: #04070f;
  font-weight: 700; border-radius: 12px; box-shadow: var(--shadow);
}
.button.ghost { background: transparent; color: var(--text); border: 1px solid var(--border); box-shadow: none; }
.button:hover { transform: translateY(-1px); }

/* Stats card (right column) */
.hero-card {
  background: radial-gradient(120% 120% at 0% 0%, var(--hero-card-1), var(--hero-card-2) 60%);
  border: 1px solid var(--border); border-radius: 18px; padding: 20px;
  display: grid; gap: 16px; align-content: center; box-shadow: var(--shadow);
  max-width: 1000px; justify-self: stretch;
}
.stat { display: grid; gap: 2px; }
.stat-number { font-size: 20px; font-weight: 800; letter-spacing: .5px; }
.stat-label { color: var(--muted); font-size: 0.9rem; }

/* ====== Sections ====== */
.section { padding: 32px 0; }
.section-head { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; }
.section-title { font-size: 1.4rem; margin: 0 0 8px; }
.see-all { color: var(--muted); }
.see-all:hover { color: var(--text); }

.pill-list { display: flex; flex-wrap: wrap; gap: 10px; padding-left: 0; list-style: none; margin: 16px 0 0; }
.pill-list li { background: var(--panel); border: 1px solid var(--border); padding: 6px 10px; border-radius: 999px; color: var(--muted); }

/* ====== Cards (Projects) ====== */
.grid.cards { display: grid; gap: 16px; grid-template-columns: repeat(3, minmax(0,1fr)); margin-top: 20px;  }
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: 16px;
  padding: 16px; box-shadow: var(--shadow); 
}
.card h4 { margin-top: 0; margin-bottom: 6px; font-size: 1.1rem; }
.card p { margin: 0 0 12px; color: var(--muted); }
.card-link { font-weight: 600; }
.card-badge {
  display: inline-block; font-size: 12px; text-transform: uppercase; letter-spacing: .08em;
  background: #163255; color: #b8d6ff; padding: 4px 8px; border-radius: 999px; margin-bottom: 10px; border: 1px solid #34557d;
}

/* ====== Publications ====== */
.pub-list { padding-left: 18px; margin: 8px 0 0; }
.pub-venue { color: var(--muted); }

/* ====== Team ====== */
.people { list-style: none; padding-left: 0; margin: 8px 0 0; }
.people li { background: var(--panel); border: 1px solid var(--border); padding: 10px 12px; border-radius: 12px; margin-bottom: 8px; }

/* ====== Footer ====== */
.site-footer { border-top: 1px solid var(--border); margin-top: 40px; }
.footer-inner { padding: 18px 0; color: var(--muted); text-align: center; }

/* ====== Activity / Gallery (kept to same site width) ====== */
.gallery-row {
  max-width: var(--content-max);
  margin: 0 auto 40px;
  padding: 0 20px;              /* match container side padding */
}
.gallery-row h4 {
  color: var(--brand); font-weight: 700; font-size: 1.1rem;
  margin: 20px 0 10px;
}
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 8px;                     /* small breathing room between images */
}
.gallery figure {
  margin: 0; border: none; border-radius: 0; box-shadow: none;
  overflow: hidden; text-align: center; transition: transform 0.2s ease;
}
.gallery figure:hover { transform: scale(1.02); }
.gallery img { width: 100%; height: 300px; object-fit: cover; display: block; }
.gallery figcaption {
  padding: 10px; font-size: 0.95rem; color: var(--muted);
  background: var(--panel); border-top: none;
}

/* ====== Theme Toggle Button ====== */
.theme-toggle {
  margin-left: 10px; display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; border-radius: 10px; border: none; background: transparent; color: var(--text); cursor: pointer;
}
.theme-toggle:hover { filter: brightness(1.05); }
.theme-toggle:focus { outline: 2px solid var(--brand); outline-offset: 2px; }
.theme-toggle .toggle-icon { font-size: 18px; line-height: 1; }

/* ====== Light Theme ====== */
:root[data-theme="light"] {
  --hero-card-1: #eaf2ff;
  --hero-card-2: #ffffff;
  --bg: #ffffff;
  --panel: #f5f7fb;
  --text: #0b1220;
  --muted: #4b5563;
  --brand: #5da7ff;
  --brand-2: #0ea5e9;
  --headerbrand: #5da7ff;
  --headerbrand-2: #9bffd6;
  --card: #ffffff;
  --border: #e5e7eb;
  --shadow: 0 10px 25px rgba(0,0,0,.06);
  color-scheme: light;
}

:root[data-theme="light"] .card,
:root[data-theme="light"] .people li { border-color: #e7eaf0; box-shadow: var(--shadow); }

:root[data-theme="light"] .button.ghost { border-color: #d7dce5; }
:root[data-theme="light"] .card-badge { background: #eef4ff; color: #173a7a; border-color: #d5e2ff; }
:root[data-theme="light"] .nav a:hover { background: #eef1f7; border-color: #d7dce5; text-decoration: none; }
:root[data-theme="light"] .pill-list li { background: #f3f6fb; border-color: #e2e8f0; color: #374151; }

/* Respect system preference on first visit (no saved choice yet) */
@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --bg: #ffffff; --panel: #f5f7fb; --text: #0b1220; --muted: #4b5563;
    --brand: #1e66f5; --brand-2: #0ea5e9; --card: #ffffff; --border: #e5e7eb;
    --shadow: 0 10px 25px rgba(0,0,0,.06);
    color-scheme: light;
  }
}

/* ====== Anchor offset for sticky header ====== */
:target { scroll-margin-top: 90px; }

/* ====== Responsive ====== */
@media (max-width: 1000px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .grid.cards { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .hero-card { justify-self: center; max-width: 360px; }
}

@media (max-width: 620px) {
  .grid.cards { grid-template-columns: 1fr; }
  .nav { display: none; }
}


/* ====== Expandable Teaching Section ====== */
.expand-btn {
  background: none;
  border: none;
  color: var(--brand);
  font-weight: 600;
  cursor: pointer;
  padding: 0;
  text-align: left;
  width: 100%;
}

.expand-btn:hover {
  text-decoration: underline;
}

.expand-content {
  display: none;
  margin-top: 10px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px;
}

.expandable.open .expand-content {
  display: block;
}

/* .game-list {
  list-style: none;
  padding-left: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  max-width: 300px;
  gap: 10px;
  margin-top: 10px;
}

.game-list li {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px;
  text-align: center;
  box-shadow: var(--shadow);
}

.game-list li:hover {
  transform: translateY(-3px);
} */

.game-grid li:hover {
  transform: translateY(-4px);
  box-shadow: 0 14px 28px rgba(0,0,0,.28);
  border-color: #34557d;              /* subtle highlight border */
}

.game-grid {
  list-style: none;
  padding-left: 0;
  margin: 10px 0 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 10px;
}

.course summary {
  list-style: none;
  cursor: pointer;
  font-weight: 700;
  color: var(--brand);
  outline: none;
}
.game-grid {
  list-style: none;
  padding-left: 0;
  margin: 10px 0 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 10px;
}

.game-grid li {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: transform .15s ease;
}
.game-grid li:hover { transform: translateY(-1px); }