:root{
  --bg:#0b0c10;
  --card:#11131a;
  --text:#e8eaf0;
  --muted:#a8afc3;
  --line:#222637;
  --link:#9ad0ff;
  --max: 920px;
}

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

header{
  position: sticky;
  top: 0;
  background: rgba(11,12,16,.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  z-index: 10;
}

nav{
  max-width: var(--max);
  margin: 0 auto;
  padding: 14px 16px;
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  align-items: center;
}

nav a{
  color: var(--text);
  text-decoration: none;
  opacity: .9;
}
nav a:hover{ opacity: 1; text-decoration: underline; }
nav a:first-child{
  font-weight: 700;
  margin-right: 10px;
}

main{
  max-width: var(--max);
  margin: 0 auto;
  padding: 28px 16px 40px;
}

section{
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px 18px;
  margin: 14px 0;
}

h1{ font-size: 2rem; margin: 0 0 8px; }
h2{ font-size: 1.35rem; margin: 0 0 10px; }
h3{ font-size: 1.05rem; margin: 10px 0 6px; }

p{ margin: 10px 0; color: var(--text); }
em, .muted{ color: var(--muted); }

ul{ margin: 8px 0 0; padding-left: 20px; }
li{ margin: 6px 0; }

a{ color: var(--link); }
a:hover{ filter: brightness(1.1); }

article{
  border-top: 1px dashed var(--line);
  padding-top: 12px;
  margin-top: 12px;
}

footer{
  max-width: var(--max);
  margin: 0 auto;
  padding: 20px 16px 30px;
  color: var(--muted);
}

@media (max-width: 520px){
  h1{ font-size: 1.6rem; }
  section{ padding: 16px; }
}

nav a.active{
  text-decoration: underline;
  opacity: 1;
  font-weight: 700;
}