:root {
  --primary-color: #ff477e;
  --secondary-color: #70d6ff;
  --bg-color: #f8f9fa;
  --text-color: #333;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
  margin: 0;
  padding: 20px 10px;
  line-height: 1.6;
}

.container {
  max-width: 500px;
  margin: 0 auto;
}

header {
  text-align: center;
  margin-bottom: 20px;
}

h1 {
  color: var(--primary-color);
  font-size: 1.5rem;
  margin-bottom: 5px;
}

.subtitle {
  font-size: 0.9rem;
  color: #666;
}

.card {
  background: #fff;
  padding: 25px;
  border-radius: 20px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}

.input-group {
  margin-bottom: 15px;
}

label {
  display: block;
  font-size: 0.85rem;
  font-weight: bold;
  margin-bottom: 5px;
  color: #555;
}

input {
  width: 100%;
  padding: 12px;
  border: 2px solid #eee;
  border-radius: 10px;
  box-sizing: border-box;
  font-size: 1rem;
}

/* 歌詞入力欄を特に広く設定 */
textarea {
  width: 100%;
  min-height: 250px; /* ここで高さを確保 */
  padding: 12px;
  border: 2px solid #eee;
  border-radius: 10px;
  box-sizing: border-box;
  font-size: 0.95rem;
  line-height: 1.5;
  font-family: inherit;
  resize: vertical;
}

input:focus, textarea:focus {
  outline: none;
  border-color: var(--secondary-color);
}

button#submitBtn {
  width: 100%;
  padding: 15px;
  background: linear-gradient(135deg, var(--primary-color), #ff7096);
  color: white;
  border: none;
  border-radius: 10px;
  font-size: 1.1rem;
  font-weight: bold;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(255, 71, 126, 0.3);
  transition: transform 0.2s;
}

button#submitBtn:active { transform: scale(0.98); }
button#submitBtn:disabled { background: #ccc; box-shadow: none; }

.output-container {
  margin-top: 30px;
  animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.output-card {
  background: #fff;
  padding: 15px;
  border-radius: 15px;
  margin-bottom: 15px;
  border-left: 5px solid var(--secondary-color);
}

.output-card h3 {
  margin-top: 0;
  font-size: 0.9rem;
  color: #888;
}

.result-box {
  font-size: 0.95rem;
  white-space: pre-wrap;
  background: #fdfdfd;
  padding: 10px;
  border-radius: 5px;
}

.copy-btn {
  margin-top: 10px;
  background: #eee;
  border: none;
  padding: 5px 10px;
  border-radius: 5px;
  font-size: 0.8rem;
  cursor: pointer;
}

footer {
  text-align: center;
  font-size: 0.7rem;
  color: #bbb;
  margin-top: 30px;
}