:root {
  --bg: #0e0e12;
  --panel: #181820;
  --text: #ececf1;
  --muted: #9a9aa8;
  --accent: #7c5cff;
  --line: #2a2a36;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  padding: 48px 16px 24px;
  text-align: center;
  border-bottom: 1px solid var(--line);
}

h1 { margin: 0; font-size: 2.4rem; letter-spacing: 0.04em; }
.sub { margin: 4px 0 0; color: var(--muted); }

main {
  flex: 1;
  width: 100%;
  max-width: 880px;
  margin: 0 auto;
  padding: 32px 16px;
}

.intro { color: var(--muted); text-align: center; margin-bottom: 32px; }

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}

.card {
  display: block;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px;
  color: var(--text);
  text-decoration: none;
  transition: border-color 0.15s, transform 0.15s;
}
.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card h2 { margin: 0 0 6px; font-size: 1.2rem; }
.card p { margin: 0; color: var(--muted); }

.back { display: inline-block; margin-bottom: 24px; color: var(--accent); text-decoration: none; }
.back:hover { text-decoration: underline; }

ul.list { list-style: none; padding: 0; margin: 0; }
ul.list li { border-bottom: 1px solid var(--line); padding: 12px 0; }
ul.list a { color: var(--text); text-decoration: none; }
ul.list a:hover { color: var(--accent); }
.hint { color: var(--muted); font-size: 0.95rem; }

footer {
  padding: 24px 16px;
  text-align: center;
  color: var(--muted);
  border-top: 1px solid var(--line);
}