* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #1e3c72, #2a5298);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 20px;
  padding: 20px;
}

/* CONTENEDOR SUPERIOR */
.top {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 15px;
  width: 100%;
}

/* BOTÓN */
.btn {
  background: white;
  color: #2a5298;
  border: none;
  padding: 12px 24px;
  font-size: 16px;
  font-weight: bold;
  border-radius: 25px;
  cursor: pointer;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  transition: all 0.2s ease;
}

.btn:hover {
  background: #2a5298;
  color: white;
  transform: scale(1.05);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
}

/* CONTENEDOR DE TARJETAS */
.contenedor {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(90px, 1fr));
  gap: 15px;
  width: 100%;
  max-width: 700px;
}

/* TARJETAS */
.item {
  background: white;
  color: #2a5298;
  font-size: 22px;
  font-weight: bold;
  border-radius: 15px;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 90px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
  transition: transform 0.2s, box-shadow 0.2s;
}

.item:hover {
  background:#c45800;
  transform: scale(1.05);
  box-shadow: 0 12px 25px rgba(0, 0, 0, 0.3);
}

/* CONTENEDOR DE INPUTS */
.inputs {
display: flex;
gap: 15px;
justify-content: center;
flex-wrap: wrap;
}
/* INPUT BASE */
.inputs input {
width: 140px;
padding: 12px 15px;
border-radius: 25px;

border: none;
outline: none;
font-size: 14px;
text-align: center;
font-weight: bold;
color: #2a5298;
background: white;
box-shadow: 0 5px 15px rgba(0,0,0,0.2);
transition: all 0.25s ease;
}
/* PLACEHOLDER */
.inputs input::placeholder {
color: #8aa3d0;
font-weight: normal;
}
/* HOVER */
.inputs input:hover {
transform: scale(1.05);
box-shadow: 0 8px 20px rgba(0,0,0,0.3);
}
/* FOCUS (cuando escribes) */
.inputs input:focus {
box-shadow: 0 0 0 3px rgba(42,82,152,0.3),
0 8px 20px rgba(0,0,0,0.3);
transform: scale(1.05);
}

#txtsalto {
  width: 200px;
  padding: 10px;
  border: 2px solid #3498db;
  border-radius: 8px;
  font-size: 16px;
  outline: none;
  transition: 0.3s;
}

#txtsalto:focus {
  border-color: #2ecc71;
  box-shadow: 0 0 8px rgba(46, 204, 113, 0.5);
}

#txtsalto::placeholder {
  color: #999;
}


/* TABLET */
@media (max-width: 768px) {
  .contenedor {
    grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    gap: 12px;
  }

  .item {
    font-size: 20px;
    min-height: 80px;
  }

  .btn {
    width: 100%;
    max-width: 250px;
  }
}




/* CELULAR */
@media (max-width: 480px) {
  body {
    padding: 15px;
    gap: 15px;
  }

  .contenedor {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }

  .item {
    font-size: 18px;
    min-height: 70px;
    border-radius: 12px;
  }

  .btn {
    width: 100%;
    font-size: 15px;
    padding: 10px 20px;
  }
  /* CELULAR: una tarjeta por fila */
@media (max-width: 480px) {
  .contenedor {
    grid-template-columns: 1fr;
  }
}
}