/* Manifold4D project page - Nerfies-style academic page */
:root {
  --accent: #3a6ea5;
  --accent-dark: #2c5580;
  --accent-light: #eef3f9;
  --text: #22272b;
  --text-light: #6b7480;
  --bg: #ffffff;
  --bg-soft: #f7f8fa;
  --border: #e3e6ea;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(20, 30, 50, 0.07), 0 4px 14px rgba(20, 30, 50, 0.05);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Noto Sans", "Helvetica Neue", "Segoe UI", Arial,
    "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 24px;
}

.container-wide {
  max-width: 1440px;
}

/* ---------------------------------------------------------------- hero */
.hero {
  padding: 72px 0 40px;
  text-align: center;
  background:
    radial-gradient(1200px 500px at 50% -10%, #f2f6fb 0%, rgba(255, 255, 255, 0) 70%);
}

.hero h1 {
  font-size: 2.35rem;
  font-weight: 700;
  line-height: 1.25;
  margin: 0 0 14px;
  letter-spacing: -0.01em;
}

.hero-title {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  margin: 0 0 14px;
}

.hero-name {
  font-size: 3.6rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.05;
  background: linear-gradient(100deg, #2c5580 0%, #3a6ea5 30%, #7b4fa8 68%, #c2528f 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
}

.hero-sub {
  font-size: 1.55rem;
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--text);
}

.hero .subtitle {
  font-size: 1.15rem;
  color: var(--text-light);
  max-width: 720px;
  margin: 0 auto 26px;
}

.authors {
  margin: 22px 0 6px;
  font-size: 1rem;
}

.authors a { color: var(--text); text-decoration: none; border-bottom: 1px dotted #aab; }
.authors a:hover { color: var(--accent); }

.affiliations {
  color: var(--text-light);
  font-size: 0.92rem;
  margin-bottom: 26px;
}

.btn-row {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 10px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 20px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: var(--shadow);
  transition: all 0.15s ease;
}

.btn:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-1px); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { background: var(--accent-dark); color: #fff; }

/* ---------------------------------------------------------------- sections */
section { padding: 44px 0; }
section.alt { background: var(--bg-soft); }

.section-title {
  font-size: 1.6rem;
  font-weight: 700;
  margin: 0 0 8px;
}

.section-title .bar {
  display: block;
  width: 56px;
  height: 4px;
  border-radius: 2px;
  background: var(--accent);
  margin-top: 10px;
}

.section-desc {
  color: var(--text-light);
  max-width: 820px;
  margin: 14px 0 24px;
}

/* ---------------------------------------------------------------- abstract */
.abstract-box {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 30px;
  box-shadow: var(--shadow);
  font-size: 0.98rem;
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-top: 26px;
}

.stat-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  text-align: center;
  box-shadow: var(--shadow);
}

.stat-card .num {
  font-size: 1.9rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1.2;
}

.stat-card .what {
  font-size: 0.88rem;
  color: var(--text-light);
  margin-top: 4px;
}

.figure-frame {
  margin: 28px 0 8px;
  text-align: center;
}

/* two yaw figures side by side, one row */
.figure-row {
  display: flex;
  gap: 18px;
  align-items: flex-start;
  margin-top: 6px;
}

.figure-row .figure-frame {
  flex: 1;
  min-width: 0;
  margin: 0;
}

.figure-frame img {
  max-width: 100%;
  border-radius: 6px;
  box-shadow: var(--shadow);
}

.figure-caption {
  font-size: 0.88rem;
  color: var(--text-light);
  margin-top: 10px;
  max-width: 780px;
  margin-left: auto;
  margin-right: auto;
}

/* ---------------------------------------------------------------- method bullets */
.method-points {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
  margin-top: 24px;
}

.point-card {
  background: #fff;
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  padding: 16px 18px;
  box-shadow: var(--shadow);
}

.point-card h4 { margin: 0 0 6px; font-size: 1rem; }
.point-card p { margin: 0; font-size: 0.9rem; color: var(--text-light); }

/* ---------------------------------------------------------------- video gallery */
.filter-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
  margin: 18px 0 14px;
}

.chip {
  padding: 7px 16px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: #fff;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-light);
  cursor: pointer;
  transition: all 0.12s ease;
}

.chip:hover { border-color: var(--accent); color: var(--accent); }
.chip.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.chip.toggle { color: var(--text); }

.hint-text {
  font-size: 0.82rem;
  color: var(--text-light);
}

/* 7 cards -> 4 edge-to-edge + 3 centered underneath */
.video-grid.flex-7 {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.video-row { display: flex; gap: 16px; }
.video-row.edge { justify-content: space-between; }
.video-row.center {
  position: relative;
  justify-content: center;
}

.overlay-ctrl {
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 7px;
}

.overlay-btn-fixed {
  font-size: 0.95rem;
  padding: 9px 20px;
  white-space: nowrap;
}

.overlay-note {
  font-size: 0.76rem;
  color: var(--text-light);
  white-space: nowrap;
  text-align: center;
}
.video-grid.flex-7 .video-card { width: calc(25% - 12px); }

/* 6 cards -> 3 per row */
.video-grid.flex-3 {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  row-gap: 16px;
}

.video-grid.flex-3 .video-card { width: calc(33.333% - 12px); }

.video-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: 16px;
}

.video-grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.video-grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.video-grid.cols-5 { grid-template-columns: repeat(5, 1fr); }

.video-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: border-color 0.15s ease;
}

.video-card.ours { border: 2px solid var(--accent); }

.video-frame {
  position: relative;
  aspect-ratio: 672 / 384;
  background: #000;
}

.video-frame video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

/* point cloud render overlay: ghost blend on top of each generation */
.video-frame video.overlay-video {
  position: absolute;
  inset: 0;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.show-overlay .video-frame video.overlay-video { opacity: 0.3; }

.video-card .tag {
  display: block;
  padding: 7px 10px 8px;
  font-size: 0.8rem;
  font-weight: 600;
  text-align: center;
  color: var(--text);
  background: #fff;
  border-top: 1px solid var(--border);
}

.video-card.ours .tag { color: var(--accent-dark); background: var(--accent-light); }
.video-card.ref .tag { color: var(--text-light); background: var(--bg-soft); }

.player-bar {
  display: flex;
  align-items: center;
  gap: 14px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 8px 18px;
  margin: 18px auto 4px;
  box-shadow: var(--shadow);
  max-width: 640px;
}

.player-bar button.play-btn {
  border: none;
  background: var(--accent);
  color: #fff;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  font-size: 13px;
  cursor: pointer;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.player-bar input[type="range"] {
  flex: 1;
  accent-color: var(--accent);
  cursor: pointer;
}

.player-bar .time {
  font-size: 0.82rem;
  color: var(--text-light);
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
}

.scene-hint {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-top: 10px;
  text-align: center;
}

/* ---------------------------------------------------------------- yaw sweep */
.yaw-controls {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 22px;
  box-shadow: var(--shadow);
  margin: 18px 0 6px;
}

.yaw-controls label { font-size: 0.9rem; font-weight: 600; color: var(--text-light); }

.yaw-controls input[type="range"] {
  flex: 1;
  min-width: 220px;
  accent-color: var(--accent);
  cursor: pointer;
}

.yaw-value {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent);
  min-width: 86px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

/* ---------------------------------------------------------------- user study table */
.table-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: var(--radius);
}

.us-table {
  width: 100%;
  min-width: 560px;
  border-collapse: collapse;
  font-size: 0.92rem;
  background: #fff;
  box-shadow: var(--shadow);
  border-radius: var(--radius);
  overflow: hidden;
}

.us-table th, .us-table td {
  padding: 10px 14px;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.us-table th { background: var(--bg-soft); font-weight: 700; }
.us-table td:first-child, .us-table th:first-child { text-align: left; }
.us-table tr:last-child td { border-bottom: none; }
.us-table .ours-col { background: var(--accent-light); font-weight: 700; color: var(--accent-dark); }
.us-table .second { text-decoration: underline; text-decoration-color: #b8c2cc; }
.us-table .best { font-weight: 700; color: var(--accent); }

/* ---------------------------------------------------------------- bibtex */
.bibtex-box {
  position: relative;
  background: #1e242b;
  color: #d7dee6;
  border-radius: var(--radius);
  padding: 22px 24px;
  font-family: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.8rem;
  line-height: 1.6;
  overflow-x: auto;
}

.bibtex-box pre { margin: 0; white-space: pre; }

.copy-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  border: 1px solid #3c4650;
  background: #2a323b;
  color: #c6d0da;
  border-radius: 6px;
  padding: 5px 12px;
  font-size: 0.75rem;
  cursor: pointer;
  transition: all 0.12s ease;
}

.copy-btn:hover { background: #39434e; color: #fff; }
.copy-btn.done { background: #2e7d4f; border-color: #2e7d4f; color: #fff; }

/* ---------------------------------------------------------------- footer */
footer {
  padding: 36px 0 44px;
  border-top: 1px solid var(--border);
  color: var(--text-light);
  font-size: 0.88rem;
  text-align: center;
}

/* ---------------------------------------------------------------- responsive */
@media (max-width: 860px) {
  .video-grid { grid-template-columns: repeat(2, 1fr); }
  .video-grid.cols-5 { grid-template-columns: repeat(2, 1fr); }
  .video-grid.cols-3 { grid-template-columns: repeat(2, 1fr); }
  .video-grid.flex-7 .video-row { flex-wrap: wrap; row-gap: 14px; }
  .video-grid.flex-7 .video-card { width: calc(50% - 8px); }
  .video-grid.flex-3 .video-card { width: calc(50% - 8px); }
  .figure-row { flex-direction: column; }
  .hero h1 { font-size: 1.7rem; }
  .hero-name { font-size: 2.7rem; }
  .hero-sub { font-size: 1.2rem; }
}

@media (max-width: 520px) {
  .video-grid, .video-grid.cols-2, .video-grid.cols-3, .video-grid.cols-5 {
    grid-template-columns: 1fr;
  }
  .video-grid.flex-7 .video-card,
  .video-grid.flex-3 .video-card { width: 100%; }
  .hero-name { font-size: 2.15rem; }
  .hero-sub { font-size: 1.02rem; }
  .us-table { font-size: 0.82rem; }
  .us-table th, .us-table td { padding: 8px 8px; }
}