/* =========================================================
   LabVLA · Project Page — Custom Styles
   依赖：Tailwind CDN（见 index.html）
   ========================================================= */

html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body { -webkit-font-smoothing: antialiased; background: #000 !important; }

/* ---------- 背景装饰（全黑） ---------- */
.bg-decor {
  position: fixed; inset: 0; z-index: -1; overflow: hidden;
  background: #000;
}
.orb { display: none; }
.grid-mask { display: none; }
@keyframes float {
  0%,100% { transform: translateY(0) translateX(0); }
  50%     { transform: translateY(-30px) translateX(20px); }
}

/* ---------- 导航 ---------- */
.nav {
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  background: rgba(11,13,18,0.55);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  transition: background .25s ease, border-color .25s ease;
}
.nav.scrolled {
  background: rgba(11,13,18,0.85);
  border-color: rgba(255,255,255,0.08);
}
.nav-link { position: relative; transition: color .2s ease; }
.nav-link:hover { color: #fff; }
.nav-link::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -6px; height: 2px;
  background: linear-gradient(90deg, #7C5CFF, #22D3EE);
  transform: scaleX(0); transform-origin: left; transition: transform .25s ease;
  border-radius: 2px;
}
.nav-link:hover::after,
.nav-link.active::after { transform: scaleX(1); }

.logo-mark {
  width: 22px; height: 22px; border-radius: 6px;
  background: conic-gradient(from 210deg, #7C5CFF, #22D3EE, #A3E635, #7C5CFF);
  box-shadow: 0 0 24px rgba(124,92,255,0.5);
}

/* ---------- 通用按钮 ---------- */
.btn-primary, .btn-ghost, .cta-btn {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: .55rem 1rem; border-radius: 10px; font-weight: 500; font-size: .9rem;
  transition: transform .15s ease, background .2s ease, border-color .2s ease, box-shadow .2s ease;
}
.btn-primary {
  background: linear-gradient(135deg, #7C5CFF 0%, #5B8DFE 100%);
  color: #fff; box-shadow: 0 6px 20px -6px rgba(124,92,255,0.7);
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 10px 28px -6px rgba(124,92,255,0.85); }
.btn-ghost {
  border: 1px solid rgba(255,255,255,0.14);
  color: #e2e8f0; background: rgba(255,255,255,0.02);
}
.btn-ghost:hover { background: rgba(255,255,255,0.06); border-color: rgba(255,255,255,0.22); }

.cta-btn {
  padding: .8rem 1.25rem; border-radius: 12px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.10);
  color: #f1f5f9;
  backdrop-filter: blur(8px);
}
.cta-btn:hover {
  transform: translateY(-2px);
  background: rgba(255,255,255,0.08);
  border-color: rgba(124,92,255,0.55);
  box-shadow: 0 10px 30px -10px rgba(124,92,255,0.55);
}

/* ---------- Hero ---------- */
.eyebrow {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: .35rem .9rem; border-radius: 999px;
  background: rgba(124,92,255,0.08);
  border: 1px solid rgba(124,92,255,0.25);
  color: #C4B5FD; font-size: .8rem; font-weight: 500;
  letter-spacing: .02em;
}
.hero-title-gradient {
  background: linear-gradient(120deg, #ffffff 0%, #C4B5FD 40%, #67E8F9 75%, #ffffff 100%);
  background-size: 200% 100%;
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
  animation: shine 9s ease-in-out infinite;
}
@keyframes shine {
  0%,100% { background-position: 0% 50%; }
  50%     { background-position: 100% 50%; }
}
.author { color: #cbd5e1; transition: color .2s ease; }
.author:hover { color: #fff; }

.hero-media { perspective: 1200px; }
.media-frame {
  position: relative; border-radius: 18px; overflow: hidden;
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.01));
  border: 1px solid rgba(255,255,255,0.08);
  box-shadow: 0 30px 80px -30px rgba(124,92,255,0.55), 0 0 0 1px rgba(255,255,255,0.03) inset;
  transform: rotateX(2deg);
}

/* ---------- Hero Mosaic（视频墙） ---------- */
.hero-mosaic {
  position: relative;
  height: clamp(620px, 92vh, 980px);
  margin-top: 64px;            /* 让出顶部导航 */
  overflow: hidden;
  isolation: isolate;
}

/* 外圈小视频网格（铺满整屏） */
.mosaic-bg {
  position: absolute; inset: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  grid-auto-rows: 96px;
  gap: 4px;
  padding: 4px;
  z-index: 0;
}
.mosaic-bg .tile {
  position: relative;
  border-radius: 8px;
  overflow: hidden;
  background: #0B0D12;
  filter: brightness(0.42) saturate(0.9);
  transform: scale(1);
  transition: filter .4s ease, transform .4s ease;
}
.mosaic-bg .tile:hover { filter: brightness(0.9) saturate(1.1); transform: scale(1.04); z-index: 1; }
.mosaic-bg .tile video,
.mosaic-bg .tile img,
.mosaic-bg .tile .tile-anim {
  width: 100%; height: 100%; object-fit: cover; display: block;
}

/* 中央 2×2 大视频 */
.mosaic-center {
  position: absolute;
  left: 50%; top: 50%;
  transform: translate(-50%, -50%);
  width: clamp(640px, 70vw, 1100px);
  height: clamp(380px, 56vh, 600px);
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr;
  gap: 6px;
  z-index: 2;
  border-radius: 14px;
  overflow: hidden;
  box-shadow:
    0 40px 100px -30px rgba(0,0,0,0.8),
    0 0 0 1px rgba(255,255,255,0.06);
}
.big-tile {
  position: relative;
  overflow: hidden;
  background: #0B0D12;
  filter: brightness(0.95) saturate(1.05);
  transition: filter .35s ease, transform .35s ease;
  border-radius: 6px;
}
.big-tile:hover { filter: brightness(1.08) saturate(1.15); transform: scale(1.015); z-index: 3; }
.big-tile video,
.big-tile img,
.big-tile .tile-anim {
  width: 100%; height: 100%; object-fit: cover; display: block;
}
/* 4 个动图角标 */
.big-tile__label {
  position: absolute; left: 10px; bottom: 10px;
  z-index: 2; pointer-events: none;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px; letter-spacing: .04em;
  color: #E5E7EB;
  padding: 4px 9px; border-radius: 999px;
  background: rgba(11,13,18,0.62);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,0.10);
  box-shadow: 0 6px 18px -8px rgba(0,0,0,0.6);
}
.big-tile::after {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,0.07);
  border-radius: inherit;
}

/* 暗角 + 中心文字背景晕染（让文字在 GIF 之上可读） */
.hero-overlay {
  position: absolute; inset: 0; z-index: 3; pointer-events: none;
  background:
    radial-gradient(ellipse 55% 40% at center, rgba(6,7,10,0.55) 0%, rgba(6,7,10,0.25) 40%, transparent 70%),
    radial-gradient(ellipse at center, transparent 0%, transparent 55%, rgba(6,7,10,0.5) 78%, rgba(6,7,10,0.92) 100%),
    linear-gradient(to bottom, rgba(6,7,10,0.0) 70%, rgba(6,7,10,1) 100%);
}

/* Hero 文案区（紧跟 mosaic 之下） */
.hero-caption {
  position: relative;
  padding: 3.5rem 0 4rem;
  margin-top: -2.5rem;
  z-index: 5;
}

/* 中心文字：叠加在 4 个 GIF 之上 */
.hero-content {
  position: absolute; inset: 0; z-index: 4;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  text-align: center; padding: 2rem 1.5rem;
  pointer-events: none;
}
.hero-content > * { pointer-events: auto; }
.hero-content h1 { text-shadow: 0 6px 30px rgba(0,0,0,0.95), 0 2px 8px rgba(0,0,0,0.9); }
.hero-content p  { text-shadow: 0 2px 14px rgba(0,0,0,0.95); }

/* 中央 2×2 增加柔和发光边框 */
.mosaic-center {
  box-shadow:
    0 40px 100px -30px rgba(0,0,0,0.85),
    0 0 0 1px rgba(255,255,255,0.08),
    0 0 80px -10px rgba(124,92,255,0.35);
}

/* 外圈墙 · 多列纵向无限流动 */
.mosaic-bg.mosaic-bg--flow {
  display: flex;
  flex-direction: row;
  gap: 6px;
  padding: 0;
  grid-template-columns: none;
  grid-auto-rows: auto;
  overflow: hidden;
}
.mosaic-col {
  flex: 1 1 0;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
  animation: colScroll var(--dur, 40s) linear infinite;
  animation-direction: var(--dir, normal);
  animation-delay: var(--delay, 0s);
  will-change: transform;
}
.mosaic-bg--flow .tile {
  flex: 0 0 auto;
  height: clamp(110px, 13vh, 170px);
  border-radius: 8px;
  overflow: hidden;
  background: #0B0D12;
  filter: brightness(0.5) saturate(0.95);
  transition: filter .35s ease, transform .35s ease;
}
.mosaic-bg--flow .tile:hover {
  filter: brightness(1) saturate(1.1);
  transform: scale(1.04);
  z-index: 1;
}
.mosaic-bg--flow .tile img {
  width: 100%; height: 100%; object-fit: cover; display: block;
}
@keyframes colScroll {
  0%   { transform: translateY(0); }
  100% { transform: translateY(-50%); }
}
@media (prefers-reduced-motion: reduce) {
  .mosaic-col { animation: none; }
}
@media (max-width: 768px) {
  .mosaic-bg.mosaic-bg--flow { gap: 4px; }
  .mosaic-bg--flow .tile { height: 90px; }
  /* 移动端少几列以避免太挤（隐藏部分列，使用 nth-child） */
  .mosaic-col:nth-child(n+6) { display: none; }
}

/* ---------- 动态彩色占位（视频未填时使用） ---------- */
.tile-anim {
  background:
    linear-gradient(135deg,
      hsl(var(--h, 250) 65% 22%) 0%,
      hsl(calc(var(--h, 250) + 30) 70% 32%) 50%,
      hsl(calc(var(--h, 250) + 60) 60% 18%) 100%);
  background-size: 200% 200%;
  animation: tileFlow var(--dur, 9s) ease-in-out infinite;
  animation-delay: var(--delay, 0s);
  position: relative;
}
.tile-anim::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(circle at 30% 30%, rgba(255,255,255,0.18), transparent 45%),
    radial-gradient(circle at 70% 80%, rgba(255,255,255,0.10), transparent 50%);
  mix-blend-mode: screen;
  animation: tileGlow calc(var(--dur, 9s) * 1.3) ease-in-out infinite;
  animation-delay: var(--delay, 0s);
}
.tile-anim::after {
  content: ""; position: absolute; inset: -20%;
  background: linear-gradient(115deg, transparent 40%, rgba(255,255,255,0.18) 50%, transparent 60%);
  animation: tileSheen calc(var(--dur, 9s) * 1.6) linear infinite;
  animation-delay: var(--delay, 0s);
}
@keyframes tileFlow {
  0%,100% { background-position: 0% 0%; filter: brightness(0.85); }
  50%     { background-position: 100% 100%; filter: brightness(1.05); }
}
@keyframes tileGlow {
  0%,100% { opacity: 0.4; transform: scale(1); }
  50%     { opacity: 0.9; transform: scale(1.06); }
}
@keyframes tileSheen {
  0%   { transform: translateX(-60%); }
  100% { transform: translateX(60%); }
}

/* 移动端：缩小中央视频，让外圈一圈也能看到 */
@media (max-width: 768px) {
  .mosaic-center { width: 92vw; height: 50vh; }
  .mosaic-bg { grid-template-columns: repeat(auto-fill, minmax(80px, 1fr)); grid-auto-rows: 64px; }
}

/* ---------- 节通用 ---------- */
.section { padding: 6rem 0; position: relative; }
.section-head { text-align: center; max-width: 760px; margin: 0 auto; }
.section-title {
  font-family: 'Space Grotesk', Inter, sans-serif;
  font-size: clamp(2rem, 4vw, 3rem); font-weight: 700; color: #fff; letter-spacing: -0.02em;
}
.section-title::after {
  content: ""; display: block; width: 56px; height: 3px; margin: 14px auto 0;
  border-radius: 3px;
  background: linear-gradient(90deg, #7C5CFF, #22D3EE);
}
.section-sub { margin-top: 1rem; color: #94a3b8; font-size: 1.05rem; }

/* ---------- Feature Cards ---------- */
.feature-card {
  position: relative; padding: 1.25rem; border-radius: 16px;
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.01));
  border: 1px solid rgba(255,255,255,0.08);
  transition: transform .25s ease, border-color .25s ease, box-shadow .25s ease, background .25s ease;
  overflow: hidden;
}
.feature-card::before {
  content: ""; position: absolute; inset: -1px; border-radius: inherit; padding: 1px;
  background: linear-gradient(135deg, rgba(124,92,255,0.0), rgba(34,211,238,0.0));
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor; mask-composite: exclude;
  transition: background .3s ease;
  pointer-events: none;
}
.feature-card:hover {
  transform: translateY(-4px);
  border-color: rgba(124,92,255,0.35);
  box-shadow: 0 22px 60px -25px rgba(124,92,255,0.65);
}
.feature-card:hover::before {
  background: linear-gradient(135deg, rgba(124,92,255,0.6), rgba(34,211,238,0.6));
}
.feature-card__media {
  border-radius: 12px; overflow: hidden; aspect-ratio: 1/1;
  background: rgba(0,0,0,0.3);
}
.feature-card__title {
  margin-top: 1rem; font-family: 'Space Grotesk', Inter, sans-serif;
  font-size: 1.2rem; font-weight: 600; color: #fff;
}
.feature-card__desc { margin-top: .5rem; color: #94a3b8; font-size: .95rem; line-height: 1.6; }

/* ---------- Stat Cards ---------- */
.stat-card {
  padding: 1.25rem 1rem; border-radius: 14px; text-align: center;
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.01));
  border: 1px solid rgba(255,255,255,0.08);
  transition: transform .2s ease, border-color .2s ease;
}
.stat-card:hover { transform: translateY(-2px); border-color: rgba(124,92,255,0.35); }
.stat-num {
  font-family: 'Space Grotesk', Inter, sans-serif;
  font-size: clamp(1.6rem, 2.4vw, 2.4rem); font-weight: 700;
  background: linear-gradient(135deg, #fff, #C4B5FD 60%, #67E8F9);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.stat-label { margin-top: .35rem; color: #94a3b8; font-size: .85rem; letter-spacing: .03em; text-transform: uppercase; }

/* ---------- Panel (通用容器) ---------- */
.panel {
  padding: 1rem; border-radius: 16px;
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.01));
  border: 1px solid rgba(255,255,255,0.08);
}

/* ---------- 占位区 ---------- */
.placeholder {
  position: relative; width: 100%; height: 100%;
  border-radius: 12px;
  background:
    repeating-linear-gradient(135deg, rgba(255,255,255,0.03) 0 12px, rgba(255,255,255,0.06) 12px 24px);
  border: 1px dashed rgba(255,255,255,0.18);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  color: #94a3b8; text-align: center; gap: .5rem;
  overflow: hidden;
}
.placeholder::after {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(600px 200px at 50% 120%, rgba(124,92,255,0.18), transparent 70%);
  pointer-events: none;
}
.placeholder-tag {
  font-family: 'JetBrains Mono', monospace; font-size: .7rem; letter-spacing: .12em;
  padding: .25rem .6rem; border-radius: 999px;
  background: rgba(124,92,255,0.15); border: 1px solid rgba(124,92,255,0.3);
  color: #C4B5FD;
}
.placeholder-text { font-size: .9rem; padding: 0 1rem; }

/* ---------- Bullet ---------- */
.bullet-list { color: #cbd5e1; }
.bullet-list li {
  position: relative; padding-left: 1.5rem; margin-top: .6rem; line-height: 1.55;
}
.bullet-list li::before {
  content: ""; position: absolute; left: 0; top: .55rem; width: .55rem; height: .55rem;
  border-radius: 2px;
  background: linear-gradient(135deg, #7C5CFF, #22D3EE);
}

/* ---------- Result Tile ---------- */
.result-tile {
  padding: .5rem; border-radius: 14px;
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.01));
  border: 1px solid rgba(255,255,255,0.08);
  transition: transform .2s ease, border-color .2s ease;
}
.result-tile:hover { transform: translateY(-3px); border-color: rgba(124,92,255,0.35); }
.result-tile figcaption {
  display: flex; align-items: center; gap: .6rem;
  padding: .65rem .25rem .25rem; color: #e2e8f0; font-size: .92rem;
}
.tag {
  font-family: 'JetBrains Mono', monospace; font-size: .65rem; letter-spacing: .14em;
  padding: .15rem .55rem; border-radius: 999px;
  background: rgba(124,92,255,0.18); border: 1px solid rgba(124,92,255,0.35);
  color: #C4B5FD;
}
.tag-cyan { background: rgba(34,211,238,0.15); border-color: rgba(34,211,238,0.4); color: #67E8F9; }
.tag-lime { background: rgba(163,230,53,0.15); border-color: rgba(163,230,53,0.4); color: #BEF264; }

/* ---------- Result Table ---------- */
.result-table { width: 100%; border-collapse: separate; border-spacing: 0; font-size: .95rem; }
.result-table th, .result-table td {
  padding: .85rem 1rem; text-align: center; border-bottom: 1px solid rgba(255,255,255,0.06);
}
.result-table th {
  font-family: 'Space Grotesk', Inter, sans-serif; font-weight: 600;
  color: #cbd5e1; text-transform: uppercase; letter-spacing: .06em; font-size: .78rem;
  background: rgba(255,255,255,0.02);
}
.result-table tbody tr:hover { background: rgba(255,255,255,0.025); }
.result-table .ours td { color: #fff; font-weight: 500; }
.result-table .ours { background: linear-gradient(90deg, rgba(124,92,255,0.10), rgba(34,211,238,0.06)); }
.result-table .best { color: #A3E635; font-weight: 600; }

/* ---------- BibTeX ---------- */
.bibtex-wrap {
  position: relative; border-radius: 16px;
  background: #0B0D12;
  border: 1px solid rgba(255,255,255,0.08);
  overflow: hidden;
}
.bibtex-wrap pre {
  margin: 0; padding: 1.5rem 1.25rem; overflow-x: auto;
  font-family: 'JetBrains Mono', monospace; font-size: .88rem; color: #cbd5e1; line-height: 1.7;
}
.bibtex-wrap code { color: inherit; }
.copy-btn {
  position: absolute; top: .75rem; right: .75rem;
  display: inline-flex; align-items: center;
  padding: .4rem .8rem; border-radius: 8px; font-size: .8rem;
  background: rgba(255,255,255,0.06); border: 1px solid rgba(255,255,255,0.12);
  color: #e2e8f0; cursor: pointer; transition: background .2s ease, border-color .2s ease;
}
.copy-btn:hover { background: rgba(124,92,255,0.18); border-color: rgba(124,92,255,0.4); }
.copy-btn .copy-done { display: none; color: #BEF264; }
.copy-btn.copied .copy-default { display: none; }
.copy-btn.copied .copy-done { display: inline; }

/* ---------- Team ---------- */
.team-subhead {
  margin-top: 2.5rem; text-align: center;
  font-family: 'Space Grotesk', Inter, sans-serif;
  color: #cbd5e1; font-size: 1rem; font-weight: 500;
  letter-spacing: .12em; text-transform: uppercase;
}
.member-card {
  display: flex; flex-direction: column; align-items: center; text-align: center;
  transition: transform .2s ease;
}
.member-card:hover { transform: translateY(-3px); }
.avatar {
  width: 84px; height: 84px; border-radius: 50%; overflow: hidden;
  border: 2px solid rgba(255,255,255,0.08);
  background: rgba(255,255,255,0.02);
  transition: border-color .2s ease, box-shadow .2s ease;
}
.member-card:hover .avatar {
  border-color: rgba(124,92,255,0.55);
  box-shadow: 0 12px 30px -10px rgba(124,92,255,0.55);
}
.avatar .placeholder { border-radius: 50%; border: none; font-size: .7rem; }
.member-name { margin-top: .65rem; color: #e2e8f0; font-size: .92rem; font-weight: 500; }

/* ---------- Footer ---------- */
.footer {
  margin-top: 4rem;
  background: linear-gradient(180deg, transparent, rgba(124,92,255,0.06));
  border-top: 1px solid rgba(255,255,255,0.06);
}
.footer-h {
  font-family: 'Space Grotesk', Inter, sans-serif; font-weight: 600;
  color: #cbd5e1; letter-spacing: .08em; text-transform: uppercase; font-size: .78rem;
}
.footer-list { margin-top: .75rem; display: flex; flex-direction: column; gap: .5rem; }
.footer-list a { color: #94a3b8; transition: color .15s ease; font-size: .92rem; }
.footer-list a:hover { color: #fff; }

/* ---------- 滚动出现动画 ---------- */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: translateY(0); }

/* ---------- 滚动条美化 ---------- */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: #06070A; }
::-webkit-scrollbar-thumb { background: rgba(124,92,255,0.35); border-radius: 999px; }
::-webkit-scrollbar-thumb:hover { background: rgba(124,92,255,0.6); }