:root {
  --bg: #f4f5f7;
  --card-bg: #ffffff;
  --text: #1f2430;
  --text-muted: #6b7280;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --border: #e2e5ea;
  --error: #dc2626;
  --radius: 12px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", "Meiryo", sans-serif;
}

.center-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.card {
  width: 100%;
  max-width: 360px;
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
}

.card h1 {
  font-size: 20px;
  margin: 0 0 4px;
}

.card .subtitle {
  color: var(--text-muted);
  font-size: 13px;
  margin: 0 0 24px;
}

label {
  display: block;
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 6px;
}

input[type="password"] {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 16px;
  margin-bottom: 16px;
}

input[type="password"]:focus {
  outline: 2px solid var(--primary);
  outline-offset: -1px;
}

button {
  width: 100%;
  padding: 12px 14px;
  border: none;
  border-radius: 8px;
  background: var(--primary);
  color: white;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
}

button:hover {
  background: var(--primary-hover);
}

button:disabled {
  opacity: 0.6;
  cursor: default;
}

.error-message {
  color: var(--error);
  font-size: 13px;
  margin: -8px 0 16px;
  min-height: 16px;
}

/* ダッシュボード */
.dashboard {
  max-width: 640px;
  margin: 0 auto;
  padding: 32px 20px 60px;
}

.dashboard-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.dashboard-header h1 {
  font-size: 18px;
  margin: 0;
}

.logout-link {
  color: var(--text-muted);
  font-size: 13px;
  text-decoration: none;
  cursor: pointer;
  background: none;
  border: none;
  width: auto;
  padding: 6px 10px;
}

.nav-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

@media (max-width: 480px) {
  .nav-grid {
    grid-template-columns: 1fr;
  }
}

.nav-card {
  display: block;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-decoration: none;
  color: var(--text);
}

.nav-card .nav-title {
  font-weight: 600;
  font-size: 15px;
  margin-bottom: 4px;
}

.nav-card .nav-desc {
  font-size: 13px;
  color: var(--text-muted);
}

.nav-card.disabled {
  opacity: 0.55;
  pointer-events: none;
}

.badge {
  display: inline-block;
  font-size: 11px;
  color: var(--text-muted);
  background: var(--bg);
  border-radius: 999px;
  padding: 2px 8px;
  margin-top: 8px;
}