:root {
    --primary: #8b5cf6;
    --primary-dark: #7c3aed;
    --accent: #22d3ee;
    --bg: #1a1b1e;
    --text: #e0e0e0;
    --border: #3a3b3f;
    --btn-radius: 6px;
    --bit-size: clamp(32px, 10vw, 55px);
  
    --bit-on: #10b981;
    --bit-off: #2f3034;
  }
  
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: "Segoe UI", sans-serif;
    background-color: var(--bg);
    color: var(--text);
    padding: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  
  header.header {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    max-width: 800px;
    margin-bottom: 1.5rem;
    gap: 1rem;
  }
  
  header h1 {
    font-size: 1.8rem;
    font-weight: bold;
  }
  
  .controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
  }
  
  #number-system {
    padding: 0.4rem 0.8rem;
    border-radius: var(--btn-radius);
    border: 1px solid var(--border);
    background-color: #1e293b;
    color: var(--text);
    font-size: 0.9rem;
  }
  
  .container {
    width: 100%;
    max-width: 800px;
  }
  
  #bitboard {
    display: flex;
    flex-direction: column;
    gap: 4px;
    background: #1e293b;
    padding: 1rem;
    border-radius: 8px;
    border: 1px solid var(--border);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    overflow-x: auto;
  }
  
  /* Force exactly 8 buttons per row */
  .bit-row {
    display: grid;
    grid-template-columns: repeat(8, var(--bit-size));
    justify-content: center;
    gap: 4px;
  }
  
  .bit-btn {
    width: var(--bit-size);
    height: var(--bit-size);
    font-family: monospace;
    font-size: 14px;
    border-radius: 4px;
    background-color: var(--bit-off);
    color: var(--text);
    border: 1px solid var(--border);
    cursor: pointer;
    transition: background 0.2s ease;
  }
  
  .bit-btn:hover {
    background-color: #334155;
  }
  .bit-btn.active {
    background-color: var(--bit-on);
    color: white;
    border-color: var(--primary-dark);
  }
  
  .button-group {
    margin-top: 1rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
  }
  
  .btn {
    padding: 0.6rem 1.2rem;
    font-size: 0.95rem;
    border: none;
    border-radius: var(--btn-radius);
    background-color: var(--primary);
    color: white;
    cursor: pointer;
    transition: background-color 0.2s ease;
  }
  
  #reset-bit {
    background-color: #64748b;
  }
  
  .btn:hover {
    background-color: var(--primary-dark);
  }
  
  #reset-bit:hover {
    background-color: #475569;
  }
  
  .output-display {
    margin-top: 1rem;
    padding: 1rem;
    font-size: 1.2rem;
    font-family: monospace;
    background: #1e293b;
    border-radius: 8px;
    border: 1px solid var(--border);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    min-height: 32px;
    text-align: center;
  }
  
  /* Mobile Responsiveness */
  @media (max-width: 600px) {
    body {
      padding: 1rem;
    }
  
    header h1 {
      font-size: 1.4rem;
    }
  
    .bit-btn {
      width: 36px;
      height: 36px;
      font-size: 12px;
    }
  
    .btn {
      padding: 0.5rem 1rem;
      font-size: 0.85rem;
    }
  
    #output {
      font-size: 1rem;
    }
  }