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

body{
  height: 100%;
  background-image: url(fondo2.gif);
  display:flex;
  justify-content:center;
  align-items:center;
  background:#1e1e1e;
  font-family:Arial, sans-serif;
}

.cronometro{
  background:#2d2d2d;
  padding:40px;
  border-radius:20px;
  text-align:center;
  box-shadow:0 0 20px rgba(0,0,0,0.5);
  width:400px;
}

h1{
  color:white;
  margin-bottom:20px;
}

#display{
  font-size:4rem;
  color:#00ff88;
  margin-bottom:25px;
  letter-spacing:3px;
}

.botones{
  display:flex;
  gap:15px;
  justify-content:center;
  margin-bottom:20px;
}

button{
  padding:12px 20px;
  border:none;
  border-radius:10px;
  font-size:1rem;
  cursor:pointer;
  transition:0.3s;
  color:white;
}

button:hover{
  transform:scale(1.05);
  opacity:0.9;
}

#start{
  background:#28a745;
}

#pause{
  background:#ffc107;
  color:black;
}

#reset{
  background:#dc3545;
}

#lap{
  background:#007bff;
  margin-bottom:20px;
}

h2{
  color:white;
  margin-bottom:15px;
}

#historial{
  list-style:none;
  max-height:200px;
  overflow-y:auto;
}

#historial li{
  background:#444;
  color:white;
  padding:10px;
  border-radius:8px;
  margin-bottom:10px;
}