/* PaPA: Pick-and-Place Anything — project page */

:root {
  --bg: #ffffff;
  --bg-alt: #f6f7f9;
  --bg-card: #ffffff;
  --fg: #16181d;
  --fg-muted: #5c6370;
  --fg-faint: #8a909b;
  --border: #e3e6ea;
  --accent: #1f4ea1;
  --accent-soft: #e8eefb;
  --accent-2: #d2642f;
  --ours: #1f4ea1;
  --shadow: 0 1px 2px rgba(16, 20, 30, .06), 0 8px 24px rgba(16, 20, 30, .06);
  --radius: 14px;
  --maxw: 1080px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e1116;
    --bg-alt: #141922;
    --bg-card: #161b23;
    --fg: #e8eaee;
    --fg-muted: #a3abb8;
    --fg-faint: #767f8d;
    --border: #262d38;
    --accent: #7aa7f0;
    --accent-soft: #1a2435;
    --accent-2: #e8926a;
    --ours: #7aa7f0;
    --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px rgba(0, 0, 0, .35);
  }
}

:root[data-theme="dark"] {
  --bg: #0e1116;
  --bg-alt: #141922;
  --bg-card: #161b23;
  --fg: #e8eaee;
  --fg-muted: #a3abb8;
  --fg-faint: #767f8d;
  --border: #262d38;
  --accent: #7aa7f0;
  --accent-soft: #1a2435;
  --accent-2: #e8926a;
  --ours: #7aa7f0;
  --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px rgba(0, 0, 0, .35);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
}

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

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 16px;
}

/* ---------- top bar ---------- */

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--border);
}

.topbar .wrap {
  display: flex;
  align-items: center;
  gap: 18px;
  height: 54px;
}

.topbar .brand {
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--fg);
  margin-right: auto;
}

.topbar nav {
  display: flex;
  gap: 18px;
  font-size: 14.5px;
}

.topbar nav a { color: var(--fg-muted); }
.topbar nav a:hover { color: var(--accent); text-decoration: none; }

.theme-toggle {
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--fg-muted);
  border-radius: 999px;
  width: 34px;
  height: 34px;
  cursor: pointer;
  font-size: 15px;
  line-height: 1;
  display: grid;
  place-items: center;
}
.theme-toggle:hover { color: var(--accent); border-color: var(--accent); }

@media (max-width: 760px) {
  .topbar nav { display: none; }
}

/* ---------- hero ---------- */

.hero {
  padding: 60px 0 34px;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.hero h1 {
  font-size: clamp(30px, 5.2vw, 50px);
  line-height: 1.14;
  letter-spacing: -.025em;
  margin: 0 0 10px;
  font-weight: 750;
}

.hero .subtitle {
  font-size: clamp(16px, 2.3vw, 21px);
  color: var(--fg-muted);
  margin: 0 auto 28px;
  max-width: 760px;
  font-weight: 450;
}

.hero .subtitle b { color: var(--fg); font-weight: 650; }

.authors {
  font-size: 17px;
  margin: 0 0 6px;
  line-height: 2;
}

.authors a, .authors span.author { color: var(--fg); }
.authors sup { color: var(--accent); font-size: 12px; }

.affil {
  color: var(--fg-muted);
  font-size: 15px;
  margin: 0 0 4px;
}

.note {
  color: var(--fg-faint);
  font-size: 13.5px;
  margin: 0;
}

/* ---------- buttons ---------- */

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin-top: 28px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--fg);
  color: var(--bg);
  border: 1px solid var(--fg);
  border-radius: 999px;
  padding: 9px 20px;
  font-size: 15px;
  font-weight: 560;
  transition: transform .12s ease, opacity .12s ease;
}
.btn:hover { text-decoration: none; opacity: .86; transform: translateY(-1px); }

.btn.ghost {
  background: transparent;
  color: var(--fg);
  border-color: var(--border);
}
.btn.ghost:hover { border-color: var(--accent); color: var(--accent); opacity: 1; }

.btn.disabled {
  background: transparent;
  color: var(--fg-faint);
  border-color: var(--border);
  cursor: default;
  pointer-events: none;
}

.btn svg { width: 16px; height: 16px; fill: currentColor; }

/* ---------- sections ---------- */

section { padding: 56px 0; }
section.alt { background: var(--bg-alt); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

h2 {
  font-size: clamp(24px, 3.4vw, 32px);
  letter-spacing: -.02em;
  margin: 0 0 8px;
  font-weight: 700;
}

h3 {
  font-size: 19px;
  letter-spacing: -.01em;
  margin: 0 0 6px;
  font-weight: 650;
}

.lede {
  color: var(--fg-muted);
  max-width: 760px;
  margin: 0 0 30px;
}

.section-head { margin-bottom: 30px; }
.section-head .lede { margin-bottom: 0; }

p { margin: 0 0 16px; }

/* ---------- figures ---------- */

figure {
  margin: 0 0 26px;
}

figure img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: #fff;
}

figcaption {
  font-size: 14.5px;
  color: var(--fg-muted);
  margin-top: 12px;
  line-height: 1.6;
}

figcaption b { color: var(--fg); font-weight: 650; }

.fig-narrow { max-width: 640px; margin-left: auto; margin-right: auto; }

/* ---------- key numbers ---------- */

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: 34px;
}

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

.stat .v {
  font-size: 30px;
  font-weight: 720;
  letter-spacing: -.03em;
  color: var(--accent);
  line-height: 1.2;
}

.stat .k {
  font-size: 13.5px;
  color: var(--fg-muted);
  margin-top: 4px;
  line-height: 1.45;
}

@media (max-width: 760px) {
  .stats { grid-template-columns: repeat(2, 1fr); }
}

/* ---------- pipeline cards ---------- */

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 8px 0 34px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow);
}

.card .step {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 8px;
}

.card p {
  font-size: 15px;
  color: var(--fg-muted);
  margin: 0;
}

@media (max-width: 880px) {
  .cards { grid-template-columns: 1fr; }
}

/* ---------- two column ---------- */

.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
}

@media (max-width: 880px) {
  .two-col { grid-template-columns: 1fr; gap: 24px; }
}

/* ---------- video ---------- */

.video-shell {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  background: #000;
  line-height: 0;
}

.video-shell video { width: 100%; height: auto; display: block; }

/* ---------- tables ---------- */

.table-wrap {
  overflow-x: auto;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  margin-bottom: 14px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
  font-variant-numeric: tabular-nums;
}

caption {
  caption-side: top;
  text-align: left;
  padding: 16px 20px 10px;
  font-size: 14.5px;
  color: var(--fg-muted);
}
caption b { color: var(--fg); font-weight: 650; }

th, td {
  padding: 10px 16px;
  text-align: center;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}

thead th {
  font-size: 13px;
  font-weight: 650;
  color: var(--fg-muted);
  text-transform: none;
}

tbody th, td:first-child, th:first-child { text-align: left; }

tbody tr:last-child td, tbody tr:last-child th { border-bottom: none; }

tr.ours { background: var(--accent-soft); }
tr.ours th, tr.ours td { font-weight: 650; color: var(--fg); }

td.best { font-weight: 700; }

.table-note {
  font-size: 13.5px;
  color: var(--fg-faint);
  margin: 0 0 30px;
}

/* ---------- footer ---------- */

footer {
  border-top: 1px solid var(--border);
  padding: 34px 0 48px;
  color: var(--fg-faint);
  font-size: 14px;
  text-align: center;
}

footer p { margin: 0 0 6px; }