:root{
  --bg: #0b0b10;
  --card: #0f1720;
  --text: #e6eef8;
  --muted: #9aa6b2;
  --accent: #1fb6ff;
}
[data-theme="light"] {
  --bg: #f6f8fb;
  --card: #ffffff;
  --text: #0b1720;
  --muted: #556677;
  --accent: #0077cc;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  background:var(--bg);
  color:var(--text);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
}
.header{
  display:flex;
  align-items:center;
  gap:20px;
  padding:16px 28px;
  background:linear-gradient(90deg, rgba(0,0,0,0.12), transparent);
}
.site-title{font-weight:700; font-size:20px}
.nav{margin-left:auto; display:flex; gap:12px}
.nav a{color:var(--text); text-decoration:none; padding:8px 12px; border-radius:8px}
.nav a:hover{background:rgba(255,255,255,0.03)}
.container{max-width:1100px; margin:28px auto; padding:0 18px}
.card{background:var(--card); border-radius:12px; padding:18px; box-shadow:0 6px 18px rgba(2,6,23,0.6)}
.cover{width:100%; height:auto; border-radius:10px; display:block; margin-bottom:14px}
.flex{display:flex; gap:18px; align-items:center}
.btn{display:inline-block; padding:10px 14px; border-radius:8px; background:var(--accent); color:white; text-decoration:none}
.footer{padding:18px; text-align:center; color:var(--muted); margin-top:28px}
.theme-toggle{cursor:pointer; padding:8px; border-radius:8px; background:rgba(255,255,255,0.02)}
@media(max-width:720px){
  .flex{flex-direction:column; align-items:stretch}
  .nav{display:none}
}