body {
  background: #222;
  color: #fff;
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
}
.container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}
.main-layout {
  display: flex;
  flex-direction: row; 
  align-items: flex-start;
  justify-content: center;
  gap: 24px;
  padding: 24px 0;
}
.panel {
  background: #333;
  border-radius: 12px;
  padding: 32px 0;
  box-shadow: 0 2px 8px #0006;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 40vw;
}
.panel .info {
  font-size: 2em;
  font-weight: bolder;
  margin-bottom: 12px;
}
.panel .letter-number-row {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  gap: 32px;
  margin-bottom: 14px;
}
.panel .letter, .panel .number, .panel .separator {
  font-size: 5.5em;
  font-weight: bolder;
  color: #ffd700;
  margin-bottom: 0;
}
.panel-buttons {
  display: flex;
  flex-direction: row;
  gap: 50px;
  justify-content: center;
}
.panel button {
  padding: 12px 24px;
  font-size: 1.5em;
  font-weight: bolder;
  border: 1px solid #444;
  border-radius: 6px;
  background: #222; 
  color: #fff;
  cursor: pointer;
  transition: background 0.2s;
}
.panel button:hover:enabled {
   background-color: #111;
}
.panel button:disabled {
  background-color: #cccccc; 
  color: #666666;
  cursor: not-allowed;
  box-shadow: none;
}
.bingo-matrix {
  background: #333;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 2px 8px #0006;
  display: inline-block;
}
.bingo-table {
  border-collapse: collapse;
  margin: auto;
}
.bingo-table th, .bingo-table td {
  border: 1px solid #444;
  width: 75px;
  height: 30px;
  text-align: center;
  font-size: 1em;
  color: #fff;
  background: #222;
  transition: background 0.2s, color 0.2s;
}
.bingo-table th {
  background: #fff;
  color: #222;
  font-size: 1.5em;
}
.marked {
  background: #ffd700 !important;
  color: #222 !important;
  font-weight: bold;
}