* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      height: 100vh;
      background: #0a0a0a;
      overflow: hidden;
      display: flex;
      justify-content: center;
      align-items: center;
      font-family: "Poppins", sans-serif;
    }

    /* --- Cuadrícula del fondo --- */
    .grid {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      display: grid;
      grid-template-columns: repeat(auto-fill, 45px);
      grid-auto-rows: 45px;
      gap: 4px;
      z-index: 1;
    }

    .cell {
      background: rgba(0, 247, 255, 0.03);  /* --- Color de la celda --- */
      border-radius: 4px;
      transition: background 0.3s, transform 0.3s;
    }

    .cell.active {
      background: rgba(0,255,225, 0.3);   /* --- Color de la celda activa al pasar el mouse --- */
      transform: scale(1.1);
    }

    /* --- Formulario de login --- */
    .login-container {
      position: relative;
      z-index: 2;
      background: rgba(255, 255, 255, 0.089);
      backdrop-filter: blur(12px);
      border: 1px solid rgba(255, 255, 255, 0.171);
      padding: 40px;
      border-radius: 20px;
      width: 320px;
      text-align: center;
      color: white;
      box-shadow: 0 0 30px rgba(0, 217, 255, 0.2);
      animation: fadeIn 1s ease;
    }

    .login-container h2 {
      margin-bottom: 20px;
      font-weight: 600;
      font-size: 1.8em;
    }

    .input-group {
      position: relative;
      width: 100%;
    }

    .login-container input {
      width: 100%;
      padding: 10px 40px 10px 10px;
      margin: 10px 0;
      border: none;
      border-radius: 10px;
      background: rgba(255, 255, 255, 0.2);
      color: white;
      font-size: 1em;
      outline: none;
    }

    .toggle-password {
      position: absolute;
      right: 10px;
      top: 50%;
      transform: translateY(-50%);
      cursor: pointer;
      color: #fff;
      font-size: 18px;
      user-select: none;
      transition: color 0.3s;
    }

    .toggle-password:hover {
      color: #00ffe1;
    }

    .login-container button {
      width: 100%;
      padding: 10px;
      margin-top: 15px;
      background: linear-gradient(90deg, #00ffe1, #00ffe1);
      border: none;
      border-radius: 10px;
      color: white;
      font-weight: bold;
      cursor: pointer;
      transition: background 0.3s;
    }

    .login-container button:hover {
      background: linear-gradient(90deg, #00ffe1, #00ffe1);
    }

    @keyframes fadeIn {
      from {
        opacity: 0;
        transform: translateY(-10px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }