:root {
  --bg: #fafafa;
  --fg: #1a1a1a;
  --muted: #666;
  --border: #e0e0e0;
  --accent: #4a6cf7;
  --card: #ffffff;
  --code-bg: #f0f0f0;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f0f10;
    --fg: #e8e8e8;
    --muted: #9a9a9a;
    --border: #2a2a2c;
    --accent: #7c8ff0;
    --card: #18181a;
    --code-bg: #1f1f22;
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.7;
  font-size: 16px;
}
.container {
  max-width: 880px;
  margin: 0 auto;
  padding: 48px 24px 96px;
}

header.hero {
  border-bottom: 1px solid var(--border);
  padding-bottom: 32px;
  margin-bottom: 40px;
}
header.hero h1 {
  font-size: 2.0rem;
  margin: 0 0 8px;
  letter-spacing: -0.01em;
}
header.hero .tagline {
  font-size: 1.05rem;
  color: var(--muted);
  margin: 0 0 16px;
}
.badges { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.badge {
  font-size: 0.78rem;
  padding: 3px 10px;
  border-radius: 12px;
  background: var(--code-bg);
  color: var(--fg);
  border: 1px solid var(--border);
  white-space: nowrap;
}
.badge.danger { background: #fde7e7; color: #a00; border-color: #f3c0c0; }
@media (prefers-color-scheme: dark) {
  .badge.danger { background: #2a1414; color: #f0a0a0; border-color: #5a2a2a; }
}

section { margin-bottom: 56px; }
section h2 {
  font-size: 1.4rem;
  margin: 0 0 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}
section h3 { font-size: 1.1rem; margin: 24px 0 8px; }

p { margin: 0 0 12px; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

code, pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  background: var(--code-bg);
  border-radius: 4px;
  font-size: 0.9rem;
}
code { padding: 1px 6px; }
pre { padding: 12px 16px; overflow-x: auto; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  margin: 12px 0;
}
th, td {
  text-align: left;
  padding: 8px 10px;
  border-bottom: 1px solid var(--border);
}
th { font-weight: 600; background: var(--code-bg); }

.dialog-box {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 18px;
  margin: 12px 0 18px;
  font-size: 0.92rem;
}
.dialog-box .turn { display: flex; gap: 10px; padding: 3px 0; }
.dialog-box .speaker {
  font-weight: 600;
  flex: 0 0 24px;
  color: var(--accent);
}

.audio-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 16px 0;
}
@media (max-width: 640px) {
  .audio-grid { grid-template-columns: 1fr; }
}
.audio-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
}
.audio-card h4 {
  margin: 0 0 6px;
  font-size: 0.95rem;
}
.audio-card .meta {
  font-size: 0.8rem;
  color: var(--muted);
  margin-bottom: 8px;
}
.audio-card audio { width: 100%; }

.curriculum-stages {
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
  counter-reset: stage;
}
.curriculum-stages li {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 18px 14px 56px;
  margin: 0 0 12px;
  position: relative;
  counter-increment: stage;
}
.curriculum-stages li::before {
  content: counter(stage);
  position: absolute;
  left: 16px;
  top: 14px;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--accent);
  color: white;
  font-size: 0.85rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}
.curriculum-stages .stage-title {
  font-weight: 600;
  margin: 0 0 4px;
}
.curriculum-stages .stage-meta {
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0;
}

.callout {
  border-left: 3px solid var(--accent);
  background: var(--card);
  padding: 12px 16px;
  margin: 16px 0;
  border-radius: 0 6px 6px 0;
  font-size: 0.92rem;
}
.callout.warning { border-left-color: #d97706; }

footer {
  border-top: 1px solid var(--border);
  margin-top: 64px;
  padding-top: 24px;
  font-size: 0.85rem;
  color: var(--muted);
}