body {
  font-family: 'Noto Sans JP', sans-serif;
  text-align: center;
  background-color: #121212;
  color: white;
  margin: 0;
  padding: 20px;
  min-height: 100vh;
  position: relative;
}

body::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background: linear-gradient(90deg, #ff0000, #990000);
  z-index: 10;
}

.header {
  margin-bottom: 30px;
}

.logo {
  display: inline-block;
  background: linear-gradient(135deg, #ff0000 0%, #990000 100%);
  padding: 10px 25px;
  border-radius: 8px;
  box-shadow: 0 5px 15px rgba(255, 0, 0, 0.2);
  transform: skewX(-10deg);
  margin-bottom: 10px;
}

h1 {
  font-size: 2.2rem;
  margin: 0;
  text-shadow: 2px 2px 0px rgba(0,0,0,0.5);
  transform: skewX(10deg);
  letter-spacing: 1px;
}

.subtitle {
  font-size: 1.1rem;
  color: #ff3333;
  font-weight: bold;
  margin-top: 0;
}

#game {
  display: inline-grid;
  grid-template-columns: repeat(8, 50px);
  grid-template-rows: repeat(8, 50px);
  gap: 3px;
  margin: 20px auto;
  padding: 10px;
  background-color: #333;
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.cell {
  width: 50px;
  height: 50px;
  background-color: #1e1e1e;
  border: 1px solid #444;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

.cell:hover {
  background-color: #2a2a2a;
  box-shadow: inset 0 0 5px rgba(255, 0, 0, 0.3);
}

.black, .white {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  transition: transform 0.3s ease;
  box-shadow: 0 3px 6px rgba(0, 0, 0, 0.3);
}

.black {
  background: linear-gradient(135deg, #333 0%, #000 100%);
  border: 2px solid #ff0000;
}

.white {
  background: linear-gradient(135deg, #eee 0%, #999 100%);
  border: 2px solid #666;
}

#turn {
  font-size: 1.2rem;
  margin: 20px 0;
}

.black-text {
  color: #ff3333;
  font-weight: bold;
}

.controls {
  margin: 25px 0;
}

button {
  margin: 0 8px;
  padding: 10px 20px;
  font-size: 16px;
  cursor: pointer;
  border: none;
  border-radius: 5px;
  font-weight: bold;
  transition: all 0.3s ease;
  font-family: 'Noto Sans JP', sans-serif;
}

.btn-primary {
  background-color: #ff0000;
  color: white;
}

.btn-primary:hover {
  background-color: #cc0000;
  transform: translateY(-2px);
  box-shadow: 0 5px 10px rgba(255, 0, 0, 0.2);
}

.btn-danger {
  background-color: #333;
  color: white;
  border: 2px solid #ff0000;
}

.btn-danger:hover {
  background-color: #ff0000;
  transform: translateY(-2px);
  box-shadow: 0 5px 10px rgba(255, 0, 0, 0.2);
}

.btn-secondary {
  background-color: #333;
  color: white;
}

.btn-secondary:hover {
  background-color: #444;
  transform: translateY(-2px);
  box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
}