:root {
  --bg:#ffffff;
  --text:#111827;
  --link:#2563eb;
  --header:#0f172a;
  --card:#f3f4f6;
}
body.dark {
  --bg:#0b1220;
  --text:#e5e7eb;
  --link:#60a5fa;
  --card:#111827;
}

* { box-sizing:border-box; }

body {
  margin:0;
  font-family:system-ui,-apple-system,Segoe UI,Roboto;
  background:var(--bg);
  color:var(--text);
  line-height:1.7;
}

a { color:var(--link); text-decoration:none }

header {
  background:var(--header);
  position:sticky;
  top:0;
  z-index:1000;
}

.header-inner {
  max-width:1200px;
  margin:auto;
  padding:10px 16px;
  display:flex;
  align-items:center;
  justify-content:space-between;
}

.logo img { width:120px; height:40px; }

nav a { color:#fff; margin-left:16px; font-size:15px; }

.menu-toggle { display:none; font-size:26px; color:#fff; cursor:pointer; }

@media(max-width:768px) {
  nav {
    display:none;
    position:absolute;
    top:60px;
    right:16px;
    background:#020617;
    padding:14px;
    border-radius:8px;
    flex-direction:column;
  }
  nav.active { display:flex; }
  .menu-toggle { display:block; }
}

.container {
  max-width:1200px;
  margin:auto;
  padding:16px;
  display:grid;
  grid-template-columns:3fr 1fr;
  gap:24px;
}

@media(max-width:900px) { .container { grid-template-columns:1fr; } }

.card {
  background:var(--card);
  padding:16px;
  border-radius:8px;
  margin-bottom:20px;
}

.sidebar { position:sticky; top:90px; }

.ad {
  background:#e5e7eb;
  padding:14px;
  text-align:center;
  margin-bottom:20px;
  font-size:14px;
}
body.dark .ad { background:#020617; }

footer {
  background:#020617;
  color:#cbd5f5;
  text-align:center;
  padding:32px 16px;
  margin-top:40px;
}