/* Change --accent / --accent-2 / --accent-rgb to recolor the whole page. */
:root {
  --accent: #6d6af5;
  --accent-2: #a78bfa;
  --accent-rgb: 109, 106, 245;
  --sky: #4f9fe8;
  --violet: #9b6cf0;
  --ink: #1f2937;
  --ink-2: #4b5563;
  --muted: #6b7280;
  --line: #e7e5f0;
  --soft: #f6f5fc;
  --card: rgba(255, 255, 255, 0.88);
  --ours: #efeefe;
  --video-bg: #11131c;
  --r: 28px;
  --maxw: 1040px;
  --font: Inter, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, Menlo, monospace;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  margin: 0;
  font: 16px/1.7 var(--font);
  color: var(--ink);
  background-color: #f7f7fb;
  background-image:
    radial-gradient(at 12% 4%, rgba(var(--accent-rgb), 0.16), transparent 42%),
    radial-gradient(at 88% 8%, rgba(167, 139, 250, 0.16), transparent 40%),
    radial-gradient(at 50% 60%, rgba(79, 159, 232, 0.08), transparent 50%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }
b { font-weight: 700; }

/* Top bar */
.topbar {
  position: sticky; top: 0; z-index: 40;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 8px 24px rgba(31, 41, 55, 0.05);
}
.bar-inner { max-width: 1200px; margin: 0 auto; padding: 0 24px; height: 60px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand {
  font-weight: 800; font-size: 1.25rem; letter-spacing: -0.02em; flex-shrink: 0;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.brand:hover { text-decoration: none; }
.topbar nav { display: flex; gap: 2px; overflow-x: auto; scrollbar-width: none; }
.topbar nav::-webkit-scrollbar { display: none; }
.topbar nav a { color: var(--ink); font-weight: 600; font-size: 0.92rem; padding: 6px 12px; border-radius: 999px; white-space: nowrap; }
.topbar nav a:hover { text-decoration: none; background: rgba(var(--accent-rgb), 0.08); color: var(--accent); }

/* Cards */
main { max-width: var(--maxw); margin: 0 auto; padding: 32px 16px 24px; }
.card {
  background: var(--card);
  border: 1px solid rgba(255, 255, 255, 0.6);
  border-radius: var(--r);
  box-shadow: 0 13px 42px rgba(var(--accent-rgb), 0.10), 0 1px 2px rgba(0, 0, 0, 0.03);
  padding: 44px 48px;
  margin-bottom: 32px;
}
.card h2 { font-size: 1.6rem; font-weight: 800; letter-spacing: -0.02em; margin: 0 0 10px; }
.card h3.sub { font-size: 1.2rem; font-weight: 800; letter-spacing: -0.01em; margin: 40px 0 6px; }
.intro { color: var(--ink-2); margin: 0 0 24px; }
.hl { color: var(--accent); }

/* Hero */
.hero { text-align: center; padding: 48px 48px 44px; }
.pill-tag {
  display: inline-block; padding: 4px 16px; border-radius: 999px; margin-bottom: 18px;
  font-size: 0.8rem; font-weight: 700; color: var(--accent);
  background: rgba(var(--accent-rgb), 0.1); border: 1px solid rgba(var(--accent-rgb), 0.18);
}
.hero h1 { font-size: clamp(1.6rem, 3.6vw, 2.15rem); line-height: 1.25; font-weight: 800; letter-spacing: -0.025em; margin: 0 auto 12px; max-width: 860px; }
.tagline { color: var(--ink-2); font-size: 1.05rem; margin: 0 0 22px; }
.authors { display: flex; flex-wrap: wrap; justify-content: center; gap: 4px 20px; margin: 0 0 10px; font-size: 1.08rem; }
.authors .au { color: var(--accent); font-weight: 600; }
.authors sup { color: var(--ink-2); margin-left: 1px; }
.affils { display: flex; flex-wrap: wrap; justify-content: center; gap: 2px 18px; color: var(--ink-2); font-size: 0.95rem; margin: 0; }
.affils.small { font-size: 0.85rem; color: var(--muted); margin-top: 2px; }
.venue {
  display: inline-block; margin: 22px 0 24px; font-size: 1.15rem; font-weight: 800; letter-spacing: 0.01em;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.links { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 10px 20px; border-radius: 999px;
  font-weight: 700; font-size: 0.95rem; color: var(--ink);
  background: #fff; border: 1px solid var(--line);
  box-shadow: 0 6px 16px rgba(31, 41, 55, 0.05);
  transition: transform .15s, box-shadow .15s;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); box-shadow: 0 10px 22px rgba(var(--accent-rgb), 0.16); }
.btn svg { width: 17px; height: 17px; }
.btn.primary { color: #fff; border-color: transparent; background: linear-gradient(135deg, var(--accent), var(--accent-2)); box-shadow: 0 8px 20px rgba(var(--accent-rgb), 0.28); }
.btn small { font-size: 0.7rem; font-weight: 600; opacity: 0.65; }
.btn.disabled { cursor: not-allowed; }
.btn.disabled:hover { transform: none; }
.btn.disabled:not(.primary) { color: var(--muted); }

/* Figures */
.figure { margin: 0 0 24px; }
.figure:last-child { margin-bottom: 0; }
.figure img { width: 100%; border-radius: 16px; background: #fff; border: 1px solid var(--line); }
.figure figcaption { margin-top: 14px; font-size: 0.94rem; color: var(--ink-2); line-height: 1.65; }
.figure figcaption b { color: var(--ink); }
.zoomable img { cursor: zoom-in; }

.abstract { margin: 0; text-align: justify; hyphens: auto; }

/* Feature cards under the method figure */
.features { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; margin: 32px 0; }
.feature { border-radius: 20px; padding: 20px 22px; background: #fff; border: 1px solid var(--line); box-shadow: 0 6px 18px rgba(31,41,55,0.04); }
.feature h3 { margin: 0 0 6px; font-size: 1.25rem; font-weight: 800; letter-spacing: -0.015em; }
.feature p { margin: 0; color: var(--ink-2); font-size: 0.93rem; line-height: 1.6; }
.f1 h3 { color: var(--sky); }
.f2 h3 { color: var(--accent); }
.f3 h3 { color: var(--violet); }
.eq { font-family: var(--mono); font-size: 0.84rem; background: var(--soft); padding: 1px 6px; border-radius: 5px; white-space: nowrap; color: var(--ink); }

.box { font-weight: 700; padding: 0 6px; border-radius: 4px; }
.box.y { color: #a87a00; background: #fff4cc; }
.box.r { color: #c0392b; background: #fde4e1; }
.box.b { color: #2563eb; background: #e1ecff; }

/* Tabs */
.tabs { display: inline-flex; flex-wrap: wrap; gap: 4px; padding: 5px; margin: 0 0 20px; border-radius: 999px; background: var(--soft); border: 1px solid var(--line); }
.tabs button { font: 600 0.9rem var(--font); cursor: pointer; padding: 7px 18px; border-radius: 999px; border: 0; background: transparent; color: var(--ink-2); }
.tabs button:hover { color: var(--accent); }
.tabs button[aria-selected="true"] { color: #fff; background: linear-gradient(135deg, var(--accent), var(--accent-2)); box-shadow: 0 6px 14px rgba(var(--accent-rgb), 0.25); }

/* Interactive demo */
.demo { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 24px; align-items: start; }
.stage { min-width: 0; }
.stage-bar { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 12px; flex-wrap: wrap; }
.now { margin: 0; font-size: 0.86rem; color: var(--muted); }
.seg { display: inline-flex; gap: 3px; padding: 4px; border-radius: 999px; background: var(--soft); border: 1px solid var(--line); }
.seg button { font: 600 0.86rem var(--font); cursor: pointer; padding: 6px 16px; border-radius: 999px; border: 0; background: transparent; color: var(--ink-2); }
.seg button[aria-selected="true"] { color: #fff; background: linear-gradient(135deg, var(--accent), var(--accent-2)); box-shadow: 0 6px 14px rgba(var(--accent-rgb), 0.25); }

.viewer { position: relative; border-radius: 20px; overflow: hidden; background: var(--video-bg); box-shadow: 0 20px 40px -20px rgba(17, 19, 28, 0.45); }
.slider-view { max-width: 600px; margin: 0 auto; }
.compare { position: relative; aspect-ratio: 1 / 1; user-select: none; touch-action: pan-y; cursor: ew-resize; overflow: hidden; }
.compare .layer { position: absolute; inset: 0; }
.compare .layer video { width: 100%; height: 100%; display: block; object-fit: cover; }
.compare .top { clip-path: inset(0 calc(100% - var(--pos, 50%)) 0 0); }
.compare .handle { position: absolute; top: 0; bottom: 0; left: var(--pos, 50%); width: 3px; background: #fff; transform: translateX(-1.5px); pointer-events: none; }
.compare .handle::after {
  content: ""; position: absolute; top: 50%; left: 50%; width: 38px; height: 38px; transform: translate(-50%, -50%);
  border-radius: 50%; background-color: #fff; box-shadow: 0 4px 14px rgba(0,0,0,.3);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M9 7l-5 5 5 5M15 7l5 5-5 5' fill='none' stroke='%236d6af5' stroke-width='2.4' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-size: 20px; background-position: center; background-repeat: no-repeat;
}
.compare .tag { position: absolute; top: 12px; padding: 3px 12px; border-radius: 999px; background: rgba(17,19,28,.68); color: #fff; font-size: 0.8rem; font-weight: 700; pointer-events: none; }
.compare .tag.l { left: 12px; }
.compare .tag.r { right: 12px; background: linear-gradient(135deg, var(--accent), var(--accent-2)); }

.grid-view { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 6px; padding: 6px; }
.tile { margin: 0; position: relative; border-radius: 10px; overflow: hidden; }
.tile video { width: 100%; aspect-ratio: 1 / 1; display: block; object-fit: cover; }
.tile figcaption { position: absolute; left: 6px; bottom: 6px; padding: 1px 8px; border-radius: 999px; background: rgba(17,19,28,.7); color: #fff; font-size: 0.72rem; font-weight: 700; }
.tile.ours { box-shadow: inset 0 0 0 3px var(--accent); }
.tile.ours video { padding: 3px; }
.tile.note { display: grid; place-items: center; padding: 12px; aspect-ratio: 1 / 1; text-align: center; font-size: 0.8rem; color: #9aa0b8; background: rgba(255,255,255,0.04); }
.tile.ours figcaption { background: linear-gradient(135deg, var(--accent), var(--accent-2)); }

.loading { position: absolute; inset: 0; display: grid; place-items: center; background: rgba(17,19,28,.35); pointer-events: none; }
.loading[hidden] { display: none; }
.loading span { width: 34px; height: 34px; border-radius: 50%; border: 3px solid rgba(255,255,255,.3); border-top-color: #fff; animation: spin .8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.parking { position: absolute; width: 1px; height: 1px; overflow: hidden; opacity: 0; pointer-events: none; }

.controls { display: flex; align-items: center; gap: 12px; margin-top: 12px; padding: 8px 12px; border-radius: 999px; background: var(--soft); border: 1px solid var(--line); }
.play { flex-shrink: 0; width: 34px; height: 34px; border-radius: 50%; border: 0; cursor: pointer; background: linear-gradient(135deg, var(--accent), var(--accent-2)) center / cover; position: relative; }
.play::before, .play::after { content: ""; position: absolute; top: 11px; width: 4px; height: 12px; background: #fff; border-radius: 1px; }
.play::before { left: 12px; }
.play::after { left: 18px; }
.play.paused::before { left: 13px; width: 0; height: 0; border-radius: 0; background: none; border-style: solid; border-width: 6px 0 6px 10px; border-color: transparent transparent transparent #fff; }
.play.paused::after { display: none; }
.scrub { flex: 1; min-width: 60px; accent-color: var(--accent); }
.time { font: 0.8rem var(--mono); color: var(--muted); width: 48px; text-align: right; }
.speed { display: flex; gap: 2px; }
.speed button { font: 600 0.78rem var(--font); cursor: pointer; padding: 4px 9px; border-radius: 999px; border: 0; background: transparent; color: var(--ink-2); }
.speed button[aria-pressed="true"] { background: #fff; color: var(--accent); box-shadow: 0 2px 6px rgba(31,41,55,0.08); }

.picker { background: var(--soft); border-radius: 20px; padding: 6px 16px 18px; }
.pick-group { margin: 14px 0 8px; font-size: 0.74rem; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); }
.thumbs { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; }
.thumb { position: relative; padding: 0; border: 0; cursor: pointer; border-radius: 12px; overflow: hidden; background: var(--video-bg); aspect-ratio: 1 / 1; outline: 2px solid transparent; outline-offset: 2px; transition: outline-color .15s, transform .15s; }
.thumb img { width: 100%; height: 100%; object-fit: cover; opacity: 0.8; transition: opacity .15s; }
.thumb span { position: absolute; left: 0; right: 0; bottom: 0; padding: 12px 6px 4px; font-size: 0.68rem; font-weight: 700; color: #fff; text-align: left; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; background: linear-gradient(transparent, rgba(0,0,0,.65)); }
.thumb:hover img { opacity: 1; }
.thumb[aria-pressed="true"] { outline-color: var(--accent); }
.thumb[aria-pressed="true"] img { opacity: 1; }
.methods { display: flex; flex-wrap: wrap; gap: 6px; transition: opacity .15s; }
.methods.muted { opacity: 0.55; }
.methods button { font: 600 0.82rem var(--font); cursor: pointer; padding: 6px 12px; border-radius: 999px; border: 1px solid var(--line); background: #fff; color: var(--ink-2); }
.methods button:hover { color: var(--accent); border-color: rgba(var(--accent-rgb), 0.4); }
.methods button[aria-pressed="true"] { color: #fff; border-color: transparent; background: linear-gradient(135deg, var(--accent), var(--accent-2)); }
.methods button:disabled { opacity: 0.4; cursor: not-allowed; }

/* Stats */
.stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 14px; margin: 0 0 32px; }
.stat { background: #fff; border: 1px solid var(--line); border-radius: 20px; padding: 18px 20px; display: flex; flex-direction: column; box-shadow: 0 6px 18px rgba(31,41,55,0.04); }
.stat .val {
  font-size: 2rem; font-weight: 800; letter-spacing: -0.03em; line-height: 1.15;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.stat .lbl { font-weight: 700; font-size: 0.92rem; margin-top: 4px; }
.stat .sub { font-size: 0.82rem; color: var(--muted); }

/* Tables */
.table-cap { margin: 0 0 10px; font-size: 0.94rem; color: var(--ink-2); }
.table-cap b { color: var(--ink); }
.table-cap .best { font-weight: 700; color: var(--accent); }
.table-cap u, table.results u { text-decoration-thickness: 1.5px; text-underline-offset: 3px; }
.table-scroll { overflow-x: auto; border-radius: 16px; border: 1px solid var(--line); background: #fff; }
table.results { width: 100%; border-collapse: collapse; white-space: nowrap; font-size: 0.86rem; font-variant-numeric: tabular-nums; }
table.results th, table.results td { padding: 9px 12px; text-align: right; border-bottom: 1px solid var(--line); }
table.results th { background: var(--soft); font-weight: 700; color: var(--ink); font-size: 0.82rem; }
table.results .l { text-align: left; }
table.results th.c { text-align: center; }
table.results td.t { color: var(--muted); }
table.results th.grp { text-align: center; color: var(--accent); }
table.results .gs, table.results th.grp { border-left: 1px solid var(--line); }
table.results tbody tr:last-child td { border-bottom: 0; }
table.results tr.sep td { border-top: 2px solid var(--line); }
table.results tbody tr:hover td { background: #faf9ff; }
table.results tr.ours td { background: var(--ours); }
table.results tr.ours td:first-child { font-weight: 700; color: var(--accent); }
table.results b { color: var(--accent); }
table.results td.y { text-align: center; color: var(--accent); font-weight: 700; }
table.results td.x { text-align: center; color: #c4c4d0; }
table.main th, table.main td { padding: 8px 9px; font-size: 0.82rem; }
table.main th:first-child, table.main td:first-child { padding-left: 16px; }
table.main th:last-child, table.main td:last-child { padding-right: 16px; }
table.main .ty { margin-left: 4px; font-size: 0.7rem; color: var(--muted); }
table.main tr.ours .ty { color: var(--accent); opacity: 0.75; }
table.main tr.grp-row td { padding: 6px 16px; text-align: left; font-size: 0.72rem; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); background: #fbfbfe; }
table.main tbody tr.grp-row:hover td { background: #fbfbfe; }
table.compact th, table.compact td { padding: 8px 7px; font-size: 0.8rem; }
table.compact th:first-child, table.compact td:first-child { padding-left: 12px; }
table.compact th:last-child, table.compact td:last-child { padding-right: 12px; }

.two-col { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; margin-top: 28px; }
.two-col.flush { margin: 0 0 28px; }
.panel { min-width: 0; background: var(--soft); border-radius: 20px; padding: 20px 18px; }
.panel h3 { margin: 0; font-size: 1.15rem; font-weight: 800; letter-spacing: -0.01em; }
.panel-sub { margin: 2px 0 14px; color: var(--muted); font-size: 0.86rem; }
.note { margin: 10px 0 0; font-size: 0.82rem; color: var(--muted); line-height: 1.55; }

.bars { display: grid; gap: 7px; }
.bar { display: grid; grid-template-columns: 82px minmax(0, 1fr) 48px; align-items: center; gap: 10px; font-size: 0.84rem; }
.bar .name { color: var(--ink-2); }
.bar .track { height: 10px; background: #e9e8f3; border-radius: 999px; overflow: hidden; }
.bar .fill { display: block; height: 100%; width: var(--w); background: #c3c2d6; border-radius: 999px; }
.bar .val { text-align: right; color: var(--muted); font-variant-numeric: tabular-nums; }
.bar.us .name, .bar.us .val { color: var(--accent); font-weight: 700; }
.bar.us .fill { background: linear-gradient(90deg, var(--accent), var(--accent-2)); }

/* BibTeX */
.bib { position: relative; margin-top: 16px; }
.bib pre { margin: 0; padding: 22px 24px; background: var(--soft); border: 1px solid var(--line); border-radius: 16px; overflow-x: auto; font: 0.85rem/1.7 var(--mono); color: var(--ink); }
.copy { position: absolute; top: 12px; right: 12px; font: 700 0.8rem var(--font); padding: 6px 14px; border-radius: 999px; border: 0; color: #fff; background: linear-gradient(135deg, var(--accent), var(--accent-2)); cursor: pointer; }

footer { text-align: center; padding: 8px 16px 40px; color: var(--muted); font-size: 0.86rem; }

/* Lightbox */
.lightbox { position: fixed; inset: 0; z-index: 60; background: rgba(17,19,28,.9); overflow: auto; padding: 24px; display: flex; align-items: flex-start; justify-content: center; }
.lightbox[hidden] { display: none; }
.lightbox img { max-width: none; width: min(2400px, 180vw); margin: auto; background: #fff; border-radius: 10px; }
.lightbox button { position: fixed; top: 14px; right: 18px; width: 40px; height: 40px; border: 0; border-radius: 50%; background: #fff; color: var(--ink); font-size: 24px; line-height: 1; cursor: pointer; }

@media (max-width: 1100px) {
  .card { padding: 36px 28px; }
}
@media (max-width: 900px) {
  .features, .two-col, .demo { grid-template-columns: 1fr; }
  .thumbs { grid-template-columns: repeat(5, minmax(0, 1fr)); }
  .stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  main { padding-top: 20px; }
  .card, .hero { padding: 28px 18px; border-radius: 22px; margin-bottom: 20px; }
  .bar-inner { padding: 0 16px; }
  .topbar nav a { padding: 6px 8px; font-size: 0.85rem; }
  .grid-view { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .thumbs { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .controls { flex-wrap: wrap; border-radius: 18px; }
  .abstract { text-align: left; }
  .lightbox img { width: 240vw; }
}