:root {
  --color-bg: #0d1117;
  --color-text: #c9d1d9;
  --color-accent: #58a6ff;
  --color-card: #161b22;
  --color-border: #30363d;
  --color-success: #3fb950;
  --color-warning: #d29922;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
}

header {
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

header nav a {
  color: var(--color-text);
  text-decoration: none;
  margin-left: 1.5rem;
  font-size: 0.95rem;
}

header nav a:hover { color: var(--color-accent); }

main {
  max-width: 900px;
  margin: 0 auto;
  padding: 3rem 2rem;
}

h1 { font-size: 2.2rem; margin-bottom: 0.5rem; }
h2 { color: var(--color-accent); margin-top: 2.5rem; }

.card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 1.5rem;
  margin: 1.5rem 0;
}

.notice {
  border-left: 3px solid var(--color-warning);
  background: rgba(210, 153, 34, 0.1);
  padding: 1rem 1.5rem;
  border-radius: 4px;
  margin: 1.5rem 0;
}

.badge-ok { color: var(--color-success); }
.badge-todo { color: var(--color-warning); }

footer {
  text-align: center;
  padding: 2rem;
  color: #6e7681;
  font-size: 0.85rem;
  border-top: 1px solid var(--color-border);
}