:root {
  --bg1: #0a0f1f;
  --bg2: #111a3a;
  --spot1: #1f2a57;
  --spot2: #3a1457;
  --neon1: #00f5ff;
  --neon2: #7b61ff;
  --neon3: #ff4ecd;
  --text: #e6f1ff;
  --muted: #9db0d0;
  --card-bg: rgba(12, 18, 38, 0.65);
  --card-border: rgba(255,255,255,0.14);
  --card-shadow1: rgba(0,245,255,0.2);
  --card-shadow2: rgba(123,97,255,0.18);
  --grid-line: rgba(255,255,255,0.07);
  --card: var(--card-bg);
  --border: var(--card-border);
  --accent: #67e8f9;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  min-height: 100vh;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: radial-gradient(1200px 600px at 20% 10%, var(--spot1) 0%, transparent 60%),
              radial-gradient(1000px 500px at 90% 90%, var(--spot2) 0%, transparent 60%),
              linear-gradient(135deg, var(--bg1), var(--bg2));
}
.nav {
  display: flex;
  gap: 14px;
  align-items: center;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  background: rgba(10, 15, 31, 0.6);
}
.nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 600;
}
.nav a:hover, .nav a.active { color: var(--accent); }
.wrap { max-width: 980px; margin: 0 auto; padding: 28px 20px 60px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px;
  margin-bottom: 16px;
}
h1 { margin: 0 0 12px; font-size: clamp(28px, 4vw, 42px); }
h2 { margin: 0 0 10px; }
p, li { color: #dbe7ff; line-height: 1.8; }
.small { color: var(--muted); font-size: 14px; }
ul { margin: 8px 0 0 18px; }
.badge {
  display:inline-block;
  padding: 6px 10px;
  border: 1px solid rgba(103,232,249,.45);
  border-radius: 999px;
  color: #bff7ff;
  font-size: 12px;
  margin-bottom: 10px;
}
.link-btn {
  display:inline-block;
  margin-top: 12px;
  padding: 10px 14px;
  border-radius: 10px;
  text-decoration: none;
  color: #052333;
  font-weight: 700;
  background: linear-gradient(90deg, #67e8f9, #22d3ee);
}


:root[data-theme="dark"] {
  --bg1: #0a0f1f;
  --bg2: #111a3a;
  --spot1: #1f2a57;
  --spot2: #3a1457;
  --neon1: #00f5ff;
  --neon2: #7b61ff;
  --neon3: #ff4ecd;
  --text: #e6f1ff;
  --muted: #9db0d0;
  --card-bg: rgba(12, 18, 38, 0.65);
  --card-border: rgba(255,255,255,0.14);
  --card-shadow1: rgba(0,245,255,0.2);
  --card-shadow2: rgba(123,97,255,0.18);
  --grid-line: rgba(255,255,255,0.07);
  --card: var(--card-bg);
  --border: var(--card-border);
  --accent: #67e8f9;
}

:root[data-theme="light"] {
  --bg1: #f7fbff;
  --bg2: #e8f0ff;
  --spot1: #d8ecff;
  --spot2: #f4dfff;
  --neon1: #00a8b8;
  --neon2: #5b7cff;
  --neon3: #cf4cc0;
  --text: #10213f;
  --muted: #4f678d;
  --card-bg: rgba(255, 255, 255, 0.88);
  --card-border: rgba(16,35,70,0.16);
  --card-shadow1: rgba(16, 118, 130, 0.18);
  --card-shadow2: rgba(91,124,255,0.16);
  --grid-line: rgba(20,45,88,0.08);
  --card: var(--card-bg);
  --border: var(--card-border);
  --accent: #0ea5b7;
}

.theme-toggle {
  margin-left: auto;
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 6px 10px;
  cursor: pointer;
  font-weight: 600;
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); }