html, body {
    height: 100%;
    margin: 0;
    font-family: 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, #0a0a0a, #1a1a1a);
    display: flex;
    justify-content: center;
    align-items: center;
}

#content-div {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: linear-gradient(145deg, #2e2e2e, #3a3a3a);
    border-radius: 20px;
    padding: 25px;
    width: 380px;
}

#titulo {
    color: white;
    font-size: 26px;
    letter-spacing: 2px;
    margin-bottom: 15px;
}

#inputPantalla {
    text-align: right;
    margin-left: 10px;
    width: 90%;
    height: 60px;
    border: none;
    border-radius: 10px;
    padding: 10px;
    background-color: #121212;
    color: #adff2f;
    font-size: 32px;
    font-weight: bold;
    margin-bottom: 20px;
}

#inputPantalla:focus {
    outline: none;
    box-shadow: 0 0 5px 3px #adff2f;
}

#botones {
    display: grid;
    grid-template-columns: repeat(4, 70px);
    grid-auto-rows: 70px;
    gap: 12px;
    justify-content: center;
}

#botones button {
    font-size: 22px;
    font-weight: bold;
    border-radius: 15px;
    border: none;
    background: linear-gradient(145deg, #3b3b3b, #2a2a2a);
    color: white;
    cursor: pointer;
    box-shadow: 3px 3px 8px rgba(0, 0, 0, 0.5),
                -2px -2px 6px rgba(255, 255, 255, 0.05);
    transition: all 0.2s ease;
}

#botones button:hover {
    transform: translateY(-3px);
}

#botones button.clicked {
    transform: scale(0.95);
    box-shadow: 0 0 5px 3px #adff2f;
}

#botones button.clickedclear {
    transform: scale(0.95);
    box-shadow: 0 0 5px 3px rgb(206, 75, 28);
}

#botones button.clicked\+ {
    transform: scale(0.95);
    box-shadow: 0 0 5px 3px rgb(98, 98, 218);  
}

#botones button.clicked\= {
    transform: scale(0.95);
    box-shadow: 0 0 5px 3px rgb(25, 201, 25);  
}

#botones #\= {
    background: linear-gradient(145deg, rgb(31, 161, 31), rgb(15, 134, 15));
    color: white;
}

#botones #clear {
    background: linear-gradient(145deg, rgb(252, 98, 42), rgb(224, 66, 9));
    color: white;
}

#botones #\+ {
  grid-row: span 2;
  height: 150px;
  background: linear-gradient(145deg, rgb(63, 63, 206), rgb(55, 55, 165));
  color: white;
  font-weight: bold;
}