:root{
  --bg: #0b0f17;
  --card: #0f1624;
  --text: #e8eefc;
  --muted: rgba(232,238,252,.72);
  --line: rgba(232,238,252,.12);
  --accent: #6ea8fe;
  --accent2: #8bdbb5;
  --shadow: 0 10px 30px rgba(0,0,0,.35);
  --radius: 18px;
}

*{ box-sizing: border-box; }
html, body{ height: 100%; }
body{
  margin:0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
  background: radial-gradient(1200px 800px at 15% 10%, rgba(110,168,254,.12), transparent 55%),
              radial-gradient(900px 650px at 90% 25%, rgba(139,219,181,.10), transparent 60%),
              var(--bg);
  color: var(--text);
  line-height: 1.65;
}

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

.container{
  width: min(980px, calc(100% - 32px));
  margin: 0 auto;
}

.site-header{
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(10px);
  background: rgba(11,15,23,.55);
  border-bottom: 1px solid var(--line);
}

.header-row{
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding: 14px 0;
}

.brand{
  display:flex;
  align-items:center;
  gap: 12px;
  min-width: 0;
}
.logo{
  width: 40px;
  height: 40px;
  border-radius: 12px;
  display:grid;
  place-items:center;
  font-weight: 800;
  color: #0b0f17;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  box-shadow: var(--shadow);
}
.brand-text{ min-width: 0; }
.brand-name{ font-weight: 800; letter-spacing: .3px; }
.brand-sub{ font-size: 12px; color: var(--muted); }

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  padding: 10px 12px;
  border-radius: 12px;
  background: rgba(232,238,252,.06);
  border: 1px solid var(--line);
  color: var(--text);
  font-weight: 650;
}
.btn:hover{
  background: rgba(232,238,252,.10);
  text-decoration:none;
}

.card{
  margin: 26px 0 18px;
  background: linear-gradient(180deg, rgba(232,238,252,.04), transparent 40%),
              var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.card-head{
  padding: 26px 22px 18px;
  border-bottom: 1px solid var(--line);
}

h1{
  margin:0 0 8px;
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1.25;
  letter-spacing: .2px;
}

h2{
  margin: 0 0 10px;
  font-size: 18px;
  letter-spacing: .2px;
}

.section{
  padding: 18px 22px;
  border-bottom: 1px solid var(--line);
}
.section:last-child{ border-bottom: none; }

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

.toc{
  padding: 16px 22px 18px;
  border-bottom: 1px solid var(--line);
}
.toc-title{
  font-weight: 750;
  margin-bottom: 8px;
}
.toc ol{
  margin: 0;
  padding-left: 18px;
}
.toc li{ margin: 6px 0; }

ul{
  margin: 10px 0 0;
  padding-left: 18px;
}
li{ margin: 8px 0; }

.callout{
  border-radius: 16px;
  border: 1px solid rgba(110,168,254,.22);
  background: rgba(110,168,254,.08);
  padding: 14px 14px 10px;
}
.callout-title{
  font-weight: 750;
  margin-bottom: 8px;
}

.grid-2{
  display:grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
@media (max-width: 760px){
  .grid-2{ grid-template-columns: 1fr; }
}

.info-card{
  border-radius: 16px;
  border: 1px solid var(--line);
  background: rgba(232,238,252,.03);
  padding: 14px;
}
.info-title{
  font-weight: 800;
  margin-bottom: 10px;
}
.info-line{ margin: 8px 0; }

.contact{
  display:flex;
  flex-direction:column;
  gap: 8px;
}

.footer{
  padding: 16px 0 30px;
  text-align:center;
}