body {
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  font-family: 'Segoe UI', Arial, sans-serif;
  margin: 0;
  padding: 0;
  min-height: 100vh;
}

/* Loader Styles */
.loader {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(255,255,255,0.95);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  transition: opacity 0.4s;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 5px solid #e0eafc;
  border-top: 5px solid #2d8cf0;
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: 18px;
}

@keyframes spin {
  0% { transform: rotate(0deg);}
  100% { transform: rotate(360deg);}
}

.loader-text {
  font-size: 1.1rem;
  color: #4a6fa1;
  letter-spacing: 1px;
  font-weight: 500;
  text-align: center;
  margin-top: 2px;
}

.container {
  max-width: 350px;
  margin: 60px auto;
  background: #f9fafb;
  border-radius: 18px;
  box-shadow: 0 8px 32px rgba(44, 62, 80, 0.18);
  padding: 32px 24px 24px 24px;
  text-align: center;
}

h1 {
  margin-bottom: 24px;
  color: #222;
  letter-spacing: 2px;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 80px);
  grid-template-rows: repeat(3, 80px);
  gap: 12px;
  justify-content: center;
  margin-bottom: 28px;
  background: linear-gradient(120deg, #e0eafc 0%, #cfdef3 100%);
  border-radius: 16px;
  box-shadow: 0 4px 24px rgba(44, 62, 80, 0.12);
  padding: 18px;
  transition: box-shadow 0.3s;
}

.cell {
  width: 80px;
  height: 80px;
  background: #f3f6fa;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(44, 62, 80, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  color: #4a6fa1;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, transform 0.18s;
  user-select: none;
  animation: popin 0.35s cubic-bezier(.68,-0.55,.27,1.55);
}

@keyframes popin {
  0% { transform: scale(0.7); opacity: 0; }
  80% { transform: scale(1.1); opacity: 1; }
  100% { transform: scale(1); }
}

.cell:hover {
  background: #e6ecf3;
  color: #3b4d63;
}

.status {
  min-height: 28px;
  margin-bottom: 18px;
  font-size: 1.15rem;
  color: #4a6fa1;
  font-weight: 500;
  letter-spacing: 1px;
  text-shadow: 0 1px 0 #fff;
}

#restart-btn {
  background: linear-gradient(90deg, #7ea7c7 60%, #b7cbe6 100%);
  color: #222;
  border: none;
  border-radius: 8px;
  padding: 12px 32px;
  font-size: 1.08rem;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(44, 62, 80, 0.10);
  transition: background 0.2s, box-shadow 0.2s;
  font-weight: 500;
  margin-bottom: 8px;
}

#restart-btn:hover {
  background: linear-gradient(90deg, #5d7fa3 60%, #7ea7c7 100%);
  box-shadow: 0 4px 16px rgba(44, 62, 80, 0.12);
}

.footer {
  margin-top: 32px;
  text-align: center;
  color: #888;
  font-size: 1rem;
  letter-spacing: 1px;
  padding-bottom: 12px;
}

.footer a {
  color: #4a6fa1;
  text-decoration: none;
  font-weight: 600;
  transition: color 0.2s;
}

.footer a:hover {
  color: #5d7fa3;
  text-decoration: underline;
}