:root {
  --accent: #0078ff;
  --accent-light: #e7f1ff;
  --bg: #f9fbfd;
  --card-bg: #fff;
  --border: #ddd;
  --text: #333;
  --shadow: 0 3px 8px rgba(0,0,0,0.15);
  --transition: 0.25s ease;
}

body {
  font-family: 'Noto Sans JP', sans-serif;
  background-color: var(--bg);
  color: var(--text);
  margin: 0;
  padding: 0;
  line-height: 1.7;
}

.header {
  position: relative;
  text-align: center;
  padding: 1rem 2rem;
  background: var(--accent);
  color: #fff;
  box-shadow: var(--shadow);
}

.header h1 {
  margin: 0;
  font-size: 1.8rem;
}

.header .home-link {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  display: inline-block;
  padding: 6px 14px;
  border-radius: 20px;
  background: var(--card-bg);
  border: 1px solid var(--accent);
  text-decoration: none;
  color: var(--accent);
  font-weight: 500;
  font-size: 0.9rem;
  transition: var(--transition);
  box-shadow: var(--shadow);
}

.header .home-link:hover {
  background: var(--accent);
  color: #fff;
  transform: translateY(-50%) translateY(-2px);
}

main {
  max-width: 900px;
  margin: 2rem auto;
  background: var(--card-bg);
  border-radius: 14px;
  padding: 2rem;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
}

textarea {
  width: 100%;
  font-size: 1rem;
  padding: 10px;
  border-radius: 8px;
  border: 1px solid #ccc;
  resize: vertical;
}

.action-btn {
  display: block;
  text-align: center;
  padding: 12px;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  border-radius: 8px;
  margin-top: 14px;
  font-size: 1rem;
  cursor: pointer;
}
.action-btn:hover {
  background: #0056b3;
}

#roulette {
  display: block;
  margin: 0 auto;
}

.result-text {
  text-align: center;
  font-size: 1.6rem;
  font-weight: bold;
  margin-top: 1rem;
  color: #d32f2f;
}

/* 既存の GIF ページと同じ下部デザイン */
.related-tools {
  text-align: center;
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: var(--shadow);
}

.tool-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.tool-card {
  display: inline-block;
  padding: 0.8rem 1.2rem;
  background: var(--accent-light);
  border: 1px solid var(--accent);
  border-radius: 10px;
  text-decoration: none;
  color: var(--accent);
  font-weight: 500;
  transition: var(--transition);
}

.tool-card:hover {
  background: var(--accent);
  color: #fff;
  transform: translateY(-2px);
}

footer {
  text-align: center;
  padding: 1.5rem 0;
  background-color: #f1f5f9;
  color: #555;
  font-size: 0.9rem;
  border-top: 1px solid #e2e8f0;
}