body {
  margin: 0;
  font-family: sans-serif;
  background-color: #121212;
  color: #ccc;
  display: flex;
  justify-content: center;
  align-items: start;
  min-height: 100vh;
  height: 100vh;
  /* padding-top: 5vh; */
  user-select: none;
  overflow: hidden;
}

.container {
  text-align: center;
}

.status {
  display: flex;
  justify-content: space-between;
  margin: 10px auto;
  width: 260px;
  font-size: 18px;
  height: 24px;
}

.board {
  position: relative;
  width: 255px;
  height: 255px;
  margin: 10px auto 20px;
  background-color: #1e1e1e;
}

.tile {
  background-color: #1e1e1e;
  border: 1px solid #444;
  font-size: 20px;
  font-weight: bold;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  will-change: transform;
  transition: transform 0.6s ease-in-out;
  position: absolute;
  width: 50px;
  height: 50px;
}

button {
  padding: 10px 20px;
  font-size: 18px;
  background: #333;
  color: #aaa;
  border: none;
  cursor: pointer;
  margin-top: 10px;
  border-radius: 12px;
}

#startBtn {
  width: 140px;
}

#badBtn {
  width: 100px;
}

#helpBtn {
  width: 250px;
}

.horizontal-buttons {
  display: flex;
  gap: 5px;
}

button:disabled {
  background: #222;
  cursor: default;
}

button:hover:enabled {
  background: #444;
}

.button-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px; /* ボタン間の隙間 */
  margin-bottom: 70px;
}

.hidden {
  display: none;
}

footer {
  position: absolute;
  bottom: 10px;
  width: 100%;
  text-align: center;
  font-size: 0.8rem;
  color: #666;
}

footer a {
  color: #bb86fc;
  text-decoration: none;
}

h1 {
  margin-top: 10px;
  margin-bottom: 0;
}

h3 {
  margin: 0;
  bottom: 0;
  font-size: 0.8rem;
  color: #bb86fc;
  text-decoration: none;
}