/* ===========================================================================
   VR-DAgger project page — ETH-blue theme, self-contained (no external deps)
   =========================================================================== */
:root {
  --eth:        #215CAF;   /* ETH Zürich blue           */
  --eth-dark:   #16417f;
  --eth-light:  #e8f0fb;
  --accent:     #1f8a70;   /* secondary (corrective)    */
  --ink:        #1a1d23;
  --muted:      #5b6470;
  --line:       #e4e8ee;
  --bg:         #ffffff;
  --bg-soft:    #f6f8fb;
  --radius:     14px;
  --shadow:     0 1px 2px rgba(16,30,54,.06), 0 8px 24px rgba(16,30,54,.06);
  --maxw:       1080px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  margin: 0;
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: var(--eth); text-decoration: none; }
a:hover { text-decoration: underline; }
img, video { max-width: 100%; display: block; }
h1, h2, h3 { line-height: 1.2; letter-spacing: -0.01em; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 22px; }
.section { padding: 64px 0; border-top: 1px solid var(--line); }
.section:first-of-type { border-top: none; }
.eyebrow {
  text-transform: uppercase; letter-spacing: .14em; font-size: .76rem;
  font-weight: 700; color: var(--eth); margin: 0 0 8px;
}
h2.section-title { font-size: 1.9rem; margin: 0 0 6px; }
.section-lead { color: var(--muted); margin: 0 0 30px; font-size: 1.06rem; }

/* ---------- Nav ---------- */
nav.topnav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.82);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.topnav .wrap { display: flex; align-items: center; height: 58px; gap: 8px; }
.topnav .brand { font-weight: 800; color: var(--eth); letter-spacing: -.02em; margin-right: auto; }
.topnav .brand span { color: var(--ink); }
.topnav a.navlink {
  color: var(--muted); font-weight: 600; font-size: .92rem;
  padding: 6px 10px; border-radius: 8px; text-decoration: none;
}
.topnav a.navlink:hover { color: var(--ink); background: var(--bg-soft); }
.topnav a.navlink.active { color: var(--eth); background: var(--eth-light); }
.nav-toggle { display: none; }

/* ---------- Hero ---------- */
.hero { padding: 56px 0 40px; text-align: center; }
.badge {
  display: inline-block; background: var(--eth-light); color: var(--eth-dark);
  font-weight: 700; font-size: .8rem; letter-spacing: .04em;
  padding: 5px 12px; border-radius: 999px; margin-bottom: 18px;
}
.hero h1 {
  font-size: clamp(1.7rem, 4.2vw, 2.8rem); margin: 0 auto 18px; max-width: 940px;
  letter-spacing: -0.02em; overflow-wrap: break-word; word-break: break-word; hyphens: auto;
}
.hero h1 .tt { color: var(--eth); }
.authors { font-size: 1.06rem; margin: 0 auto 6px; max-width: 960px; }
.authors a { color: var(--ink); font-weight: 600; }
.authors sup { color: var(--eth); }
.affil { color: var(--muted); margin: 0 0 4px; }
.note-eq { color: var(--muted); font-size: .9rem; margin: 0 0 22px; }

.btn-row { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin: 6px 0 8px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--ink); color: #fff; font-weight: 650; font-size: .96rem;
  padding: 11px 18px; border-radius: 999px; border: 1px solid var(--ink);
  transition: transform .12s ease, box-shadow .12s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); box-shadow: var(--shadow); }
.btn.primary { background: var(--eth); border-color: var(--eth); }
.btn.ghost { background: #fff; color: var(--ink); border-color: var(--line); }
.btn .ic { width: 18px; height: 18px; fill: currentColor; }
.btn-hint { color: var(--muted); font-size: .82rem; margin-top: 10px; }

.hero-figure { margin: 34px auto 0; }
.hero-figure img { border-radius: var(--radius); }
figcaption { color: var(--muted); font-size: .9rem; margin-top: 12px; text-align: left; }
figcaption b { color: var(--ink); }

/* ---------- Stat banner ---------- */
.stats { background: var(--bg-soft); }
.stat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.stat {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px 18px; text-align: center; box-shadow: var(--shadow);
}
.stat .num { font-size: 2rem; font-weight: 800; color: var(--eth); letter-spacing: -.02em; }
.stat .lbl { color: var(--muted); font-size: .92rem; margin-top: 4px; }

/* ---------- Generic figure block ---------- */
figure { margin: 0; }
.figure-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 14px; margin: 8px 0 0;
}
.figure-card img, .figure-card video { border-radius: 8px; width: 100%; }
.media-row { display: grid; gap: 18px; margin-top: 8px; }
.cols-2 { grid-template-columns: 1fr 1fr; }
.cols-3 { grid-template-columns: repeat(3, 1fr); }

.clip {
  border-radius: 10px; border: 1px solid var(--line); box-shadow: var(--shadow);
  width: 100%; background: #000;
}
.clip-cap { color: var(--muted); font-size: .86rem; margin-top: 8px; text-align: center; }

/* ---------- Abstract ---------- */
.abstract p { font-size: 1.08rem; }

/* ---------- Method steps ---------- */
.steps { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; margin-top: 26px; }
.step {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; box-shadow: var(--shadow);
}
.step .k {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border-radius: 8px;
  background: var(--eth-light); color: var(--eth-dark); font-weight: 800; margin-bottom: 12px;
}
.step h3 { margin: 0 0 6px; font-size: 1.08rem; }
.step p { margin: 0; color: var(--muted); font-size: .96rem; }

.callout {
  background: var(--eth-light); border: 1px solid #cfe0f6;
  border-left: 4px solid var(--eth); border-radius: 10px;
  padding: 16px 18px; margin-top: 24px; color: var(--eth-dark);
}
.callout code { background: #fff; padding: 1px 6px; border-radius: 5px; font-size: .92em; }

/* ---------- Tasks ---------- */
.task-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; margin-top: 24px; }
.task {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); overflow: hidden;
}
.task video, .task img { width: 100%; aspect-ratio: 16/10; object-fit: cover; background:#000; }
.task .body { padding: 16px 18px; }
.task .body h3 { margin: 0 0 4px; font-size: 1.1rem; }
.task .body p { margin: 0; color: var(--muted); font-size: .94rem; }
.task .tag {
  display:inline-block; font-size:.72rem; font-weight:700; letter-spacing:.05em;
  text-transform:uppercase; color: var(--eth); background: var(--eth-light);
  padding:2px 8px; border-radius:999px; margin-bottom:8px;
}

/* ---------- Results table ---------- */
.table-scroll { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }
table.results { border-collapse: collapse; width: 100%; font-size: .86rem; min-width: 900px; background:#fff; }
table.results th, table.results td { padding: 8px 10px; text-align: center; white-space: nowrap; }
table.results thead th {
  background: var(--eth); color: #fff; font-weight: 700; border-bottom: 2px solid var(--eth-dark);
  position: sticky; top: 0;
}
table.results thead tr:nth-child(2) th { background: var(--eth-dark); font-weight: 600; font-size:.8rem; }
table.results tbody td:first-child, table.results tbody th { text-align: left; font-weight: 600; }
table.results tbody tr:nth-child(odd) { background: var(--bg-soft); }
table.results tbody tr.group-start td { border-top: 2px solid #cdd6e3; }
table.results td .std { color: var(--muted); font-size: .76em; }
table.results td.best { color: var(--eth-dark); font-weight: 800; }
table.results td.second { text-decoration: underline; text-decoration-color: #9bb6df; }
.legend { color: var(--muted); font-size: .86rem; margin-top: 10px; }
.legend b { color: var(--eth-dark); }

/* ---------- BibTeX ---------- */
.bibtex-box { position: relative; }
pre.bibtex {
  background: #0f1722; color: #d7e2f1; border-radius: var(--radius); padding: 22px;
  overflow-x: auto; font-size: .86rem; line-height: 1.55; margin: 0;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
.copy-btn {
  position: absolute; top: 12px; right: 12px;
  background: rgba(255,255,255,.12); color: #fff; border: 1px solid rgba(255,255,255,.25);
  border-radius: 8px; padding: 6px 12px; font-size: .82rem; font-weight: 600; cursor: pointer;
}
.copy-btn:hover { background: rgba(255,255,255,.22); }

/* ---------- Footer ---------- */
footer { background: var(--bg-soft); border-top: 1px solid var(--line); padding: 40px 0; }
footer p { color: var(--muted); font-size: .9rem; margin: 0 0 8px; }
footer .ack { font-size: .84rem; }

/* ---------- Responsive ---------- */
@media (max-width: 520px) {
  .hero h1 { font-size: 1.5rem; }
  .hero { padding: 36px 0 28px; }
  .stat .num { font-size: 1.7rem; }
  h2.section-title { font-size: 1.5rem; }
}

@media (max-width: 860px) {
  .stat-grid { grid-template-columns: repeat(2,1fr); }
  .steps, .task-grid { grid-template-columns: 1fr; }
  .cols-2, .cols-3 { grid-template-columns: 1fr; }
  .topnav .navlinks { display: none; }
  .topnav .navlinks.open {
    display: flex; flex-direction: column; position: absolute; top: 58px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--line); padding: 10px 22px; gap: 4px;
  }
  .nav-toggle {
    display: inline-flex; margin-left: auto; background: none; border: 1px solid var(--line);
    border-radius: 8px; padding: 6px 10px; font-size: 1rem; cursor: pointer; color: var(--ink);
  }
  .topnav .brand { margin-right: 0; }
}