:root {
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #1c2530;
  --muted: #596574;
  --accent: #0f766e;
  --danger: #b91c1c;
  --border: #d6dee8;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'SF Pro Text', 'Hiragino Sans', 'Noto Sans JP', sans-serif;
  background: radial-gradient(circle at 20% 0%, #e8f5f2, var(--bg) 52%);
  color: var(--text);
}

.page-header {
  padding: 24px 20px 4px;
}

.page-header h1 {
  margin: 0;
  font-size: 28px;
}

.page-header p {
  margin-top: 8px;
  color: var(--muted);
}

.layout {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 16px;
  padding: 12px 20px 24px;
}

.card {
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--card);
  padding: 16px;
  box-shadow: 0 10px 20px rgba(15, 23, 42, 0.05);
}

.card h2 {
  margin: 0 0 10px;
}

.stub-block {
  margin-bottom: 14px;
}

button {
  border: none;
  border-radius: 10px;
  background: var(--accent);
  color: #ffffff;
  padding: 10px 12px;
  margin-right: 8px;
  margin-bottom: 8px;
  cursor: pointer;
  font-weight: 600;
}

button:hover {
  opacity: 0.92;
}

button.danger {
  background: var(--danger);
}

textarea,
input {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px;
  margin-bottom: 8px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 13px;
  background: #fbfdff;
}

.result {
  margin: 8px 0 0;
  min-height: 64px;
  max-height: 280px;
  overflow: auto;
  border-radius: 8px;
  padding: 10px;
  border: 1px solid var(--border);
  background: #0f172a;
  color: #d5e5ff;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12px;
}