/* ===== Meta-Ctrl project page ===== */
:root {
  --blue:      #2563EB;
  --blue-dark: #1d4ed8;
  --red:       #DC2626;
  --green:     #16A34A;
  --orange:    #F59E0B;
  --gray:      #6B7280;
  --ink:       #1f2430;
  --muted:     #5b6472;
  --line:      #e6e8ee;
  --bg:        #ffffff;
  --bg-soft:   #f7f8fb;
  --bg-soft2:  #eef2fb;
  --maxw:      1120px;
  --radius:    14px;
  --shadow:    0 1px 3px rgba(16,24,40,.06), 0 8px 24px rgba(16,24,40,.06);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 70px; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Inter", Roboto, Helvetica, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

/* ---------- top nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255,255,255,.85);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 11px 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.nav-brand { font-weight: 700; letter-spacing: -.01em; color: var(--ink); }
.nav-brand .mc { color: var(--blue); }
.nav-links { display: flex; gap: 20px; flex-wrap: wrap; }
.nav-links a { color: var(--muted); font-size: 15px; font-weight: 500; }
.nav-links a:hover { color: var(--blue); text-decoration: none; }
@media (max-width: 680px) { .nav-links { display: none; } }

/* ---------- layout ---------- */
section { max-width: var(--maxw); margin: 0 auto; padding: 54px 22px; }
section + section { border-top: 1px solid var(--line); }

h1, h2, h3 { letter-spacing: -.02em; line-height: 1.2; }
h2 {
  font-size: 28px;
  margin: 0 0 6px;
  text-align: center;
}
.section-sub {
  text-align: center;
  color: var(--muted);
  margin: 0 auto 30px;
  max-width: 640px;
  font-size: 16px;
}

/* ---------- hero ---------- */
.hero {
  max-width: var(--maxw);
  margin: 0 auto;
  text-align: center;
  padding: 56px 22px 30px;
}
.hero figure { max-width: 860px; margin-left: auto; margin-right: auto; }
.hero h1 {
  font-size: 40px;
  margin: 0 0 6px;
  font-weight: 800;
}
.hero .subtitle {
  font-size: 21px;
  color: var(--muted);
  font-weight: 500;
  margin: 0 auto 22px;
  max-width: 760px;
  letter-spacing: -.01em;
}
.venue {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--blue-dark);
  background: var(--bg-soft2);
  border: 1px solid #d6e0fb;
  padding: 4px 14px;
  border-radius: 999px;
  margin-bottom: 22px;
}
.authors { font-size: 18px; margin: 4px 0 2px; }
.authors a { color: var(--ink); font-weight: 600; }
.affil { color: var(--muted); font-size: 15px; margin: 2px 0 24px; }

/* ---------- buttons ---------- */
.btns { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-top: 6px; }
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--ink);
  color: #fff;
  padding: 10px 20px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid var(--ink);
  transition: transform .08s ease, background .15s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); background: #000; }
.btn.secondary { background: #fff; color: var(--ink); border-color: var(--line); }
.btn.secondary:hover { background: var(--bg-soft); }
.btn .ico { font-size: 16px; line-height: 1; }

/* ---------- figures ---------- */
figure { margin: 22px 0 0; }
figure img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  background: #fff;
}
figcaption {
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.55;
  margin-top: 12px;
  text-align: center;
}
figcaption b { color: var(--ink); }
.fig-narrow { max-width: 720px; margin-left: auto; margin-right: auto; }

/* ---------- abstract ---------- */
.abstract p { margin: 0 auto; max-width: 760px; text-align: justify; color: #2b313d; }

/* ---------- key-points grid ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 8px;
}
@media (max-width: 760px) { .grid { grid-template-columns: 1fr; } }
.card {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 20px 18px;
}
.card .big { font-size: 30px; font-weight: 800; letter-spacing: -.02em; color: var(--blue); line-height: 1.1; }
.card .lbl { font-weight: 700; margin: 8px 0 4px; }
.card .desc { font-size: 14.5px; color: var(--muted); margin: 0; }

/* ---------- method steps ---------- */
.steps { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin-top: 10px; }
@media (max-width: 760px) { .steps { grid-template-columns: 1fr; } }
.step {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  background: #fff;
}
.step .tag {
  display: inline-block;
  font-size: 12.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .04em;
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 10px;
}
.step.syntax .tag { background: var(--bg-soft2); color: var(--blue-dark); }
.step.semantics .tag { background: #fef3c7; color: #b45309; }
.step h3 { margin: 0 0 8px; font-size: 19px; }
.step p { margin: 0; font-size: 15.5px; color: var(--muted); }
.step .mono { font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; font-size: 13.5px; color: var(--ink); }

/* ---------- equation blocks ---------- */
.eqn-block {
  background: var(--bg-soft);
  border: 1px solid var(--line);
  border-left: 3px solid var(--blue);
  border-radius: var(--radius);
  padding: 18px 22px 14px;
  margin: 16px 0;
}
.eqn-head {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .04em;
  color: var(--blue-dark);
  margin-bottom: 2px;
}
.eqn-block mjx-container { overflow-x: auto; overflow-y: hidden; max-width: 100%; padding: 2px 0; }
.eqn-note { font-size: 15px; color: var(--muted); margin: 6px 0 0; }
.eqn-note b { color: var(--ink); }

/* ---------- tables ---------- */
.table-wrap { overflow-x: auto; margin-top: 10px; border-radius: var(--radius); border: 1px solid var(--line); }
table { border-collapse: collapse; width: 100%; font-size: 14.5px; min-width: 540px; }
caption { caption-side: top; text-align: left; color: var(--muted); font-size: 14px; padding: 0 4px 12px; }
th, td { padding: 9px 14px; text-align: center; border-bottom: 1px solid var(--line); white-space: nowrap; }
th:first-child, td:first-child { text-align: left; }
thead th { background: var(--bg-soft); font-weight: 700; color: var(--ink); }
tbody tr:hover { background: #fafbfe; }
.group-row td {
  background: var(--bg-soft2);
  font-weight: 700;
  color: var(--blue-dark);
  text-align: center;
}
.row-base td { color: var(--muted); }
.row-ours { background: #f0fdf4 !important; }
.row-ours td { font-weight: 600; }
td.best { color: var(--green); font-weight: 800; }
.tnote { font-size: 13.5px; color: var(--muted); margin-top: 12px; max-width: 820px; }

/* ---------- bibtex ---------- */
.bibtex pre {
  background: #0f1320;
  color: #d7dcea;
  border-radius: var(--radius);
  padding: 20px 22px;
  overflow-x: auto;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 13.5px;
  line-height: 1.6;
  margin: 0;
}

/* ---------- footer ---------- */
footer {
  text-align: center;
  color: var(--muted);
  font-size: 14px;
  padding: 36px 22px 50px;
  border-top: 1px solid var(--line);
}
footer a { color: var(--muted); text-decoration: underline; }