:root{
  --bg: #ffffff;
  --ink: #0b0b0f;
  --muted: #000f00;
  --border: #000000;

  --spark: #2f3ea8;        /* deep blue */
  --label: #96d2c7;        /* logo blue */
  --shadow: rgba(11, 11, 15, 0.08);

  --radius: 16px;
  --radius-sm: 12px;
  --max: 1100px;
}

*{ box-sizing: border-box; }
html, body{ height: 100%; }
body{
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  line-height: 1.6;
}

img{ max-width: 100%; height: auto; display: block; }

.container{
  width: min(var(--max), calc(100% - 2rem));
  margin-inline: auto;
}

.skip-link{
  position: absolute;
  left: -999px;
  top: 0.75rem;
  background: var(--label);
  color: var(--ink);
  padding: 0.6rem 0.8rem;
  border: 2px solid var(--ink);
  border-radius: 10px;
  font-weight: 600;
}
.skip-link:focus{ left: 1rem; z-index: 10; }

.site-header{
  position: sticky;
  top: 0;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 5;
}
.header-inner{
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 0;
  gap: 1rem;
}

.brand{
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: inherit;
  font-weight: 800;
  letter-spacing: -0.02em;
}
.brand-mark{
  width: 14px;
  height: 14px;
  border: 2px solid var(--ink);
  background: var(--label);
  box-shadow: 0 6px 16px var(--shadow);
}
.brand-text{ font-size: 0.98rem; }

.nav{
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
  justify-content: flex-end;
}
.nav a{
  text-decoration: none;
  color: var(--muted);
  font-weight: 700;
  padding: 0.45rem 0.65rem;
  border-radius: 10px;
}
.nav a:hover, .nav a:focus{
  color: var(--ink);
  outline: none;
  background: #f6f7fb;
}
.nav a[aria-current="page"]{
  color: var(--ink);
  background: #f6f7fb;
  box-shadow: 0 8px 18px var(--shadow);
}

.hero{
  padding: 4rem 1rem 5rem 1rem;
  border-bottom: 1px solid var(--border);
}
.hero-inner{
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2rem;
  align-items: center;
}
.hero-copy h1{
  font-size: clamp(2.2rem, 3.5vw, 3.2rem);
  line-height: 1.05;
  margin: 0 0 0.6rem 0;
  letter-spacing: -0.03em;
}
.lede{
  font-size: 1.05rem;
  color: var(--muted);
  margin: 0 0 1.15rem 0;
  max-width: 60ch;
}

.cta-row{
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin: 1rem 0 3rem;
}
.button{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1rem;
  text-decoration: none;
  border: 4px solid var(--ink);
  background: var(--label);
  color: var(--ink);
  font-weight: 800;
  box-shadow: 0 10px 22px var(--shadow);
}
.button:focus{ outline: 3px solid #000000; outline-offset: 2px; }
.button-ghost{
  background: transparent;
  box-shadow: none;
}

.facts{
  list-style: none;
  padding: 0;
  margin: 0.8rem 0 0;
  display: grid;
  gap: 0.5rem;
}
.facts li{
  display: flex;
  gap: 0.55rem;
  align-items: flex-start;
  color: var(--muted);
}
.dot{
  width: 10px;
  height: 10px;
  margin-top: 0.45rem;
  border-radius: 50%;
  background: var(--ink);
  flex: 0 0 auto;
}

.hero-logo{
  margin: 0;
  padding: 2rem;
  border: 3px solid var(--border);
  box-shadow: 0 20px 48px var(--shadow);
  background: #ffffff;
}

.section{
  padding: 2.6rem 0;
}
.section-alt{
  background: #fbfcff;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.section h2{
  margin: 0 0 1rem 0;
  font-size: 1.55rem;
  letter-spacing: -0.02em;
}

.h3{
  margin-top: 1.2rem;
  margin-bottom: 0.6rem;
  letter-spacing: -0.01em;
}

.grid{
  display: grid;
  gap: 1rem;
}
.grid.two{ grid-template-columns: repeat(2, minmax(0, 1fr)); }

.card{
  border: 1px solid var(--border);
  padding: 1.1rem 1.1rem;
  background: #fff;
  box-shadow: 0 18px 44px var(--shadow);
}
.card h3{
  margin: 0 0 0.5rem 0;
  letter-spacing: -0.01em;
}
.card p{
  margin: 1rem;
  margin-bottom: 3rem;
  color: var(--muted);
}

.prose p{ max-width: 105ch; }

.table-wrap{
  margin-top: 2rem;
  overflow: auto;
  border: 1px solid var(--border);
  background: #fff;
}

table{
  width: 100%;
  border-collapse: collapse;
  min-width: 650px;
}
th, td{
  border: 1px solid var(--border);
  padding: 0.75rem;
  text-align: center;
}
thead th{
  background: var(--ink);
  color: #fff;
  font-weight: 800;
}
tbody th{
  background: #f7f8fc;
  font-weight: 800;
}

.cite{
  margin-top: 0.5rem;
  font-size: 0.92rem;
  color: var(--muted);
  text-align: right;
}

.authors{
  list-style: none;
  padding: 0;
  margin: 0.75rem 0 0;
  display: grid;
  gap: 0.7rem;
}
.authors li{
  display: grid;
  gap: 0.15rem;
  padding: 0.75rem 0.8rem;
  border: 3px solid var(--border);
  background: #ffffff;
}
.name{ font-weight: 800; color: var(--ink); }
.affil{ color: var(--muted); }

.link{
  font-weight: 800;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 2px solid var(--label);
  padding-bottom: 0.05rem;
}
.link:hover, .link:focus{
  border-bottom-color: var(--spark);
  outline: none;
}

.muted{ color: var(--muted); }

.site-footer{
  border-top: 1px solid var(--border);
  padding: 1.8rem 0;
}
.footer-inner{
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  color: var(--muted);
}
.site-footer p{ margin: 0; }

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