* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Orbitron', sans-serif;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: linear-gradient(135deg, #0f0c29, #302b63, #24243e);
}

.calculadora {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    padding: 20px;
    border-radius: 20px;
    border: 2px solid rgb(35, 0, 130);
    box-shadow: 0 0 20px rgba(0, 255, 255, 0.1);
    width: 320px;
}

#display {
    width: 100%;
    height: 80px;
    font-size: 35px;
    text-align: right;
    padding: 15px;
    margin-bottom: 20px;
    border: none;
    border-radius: 10px;
    background-color: #000;
    color: #00eaff;
    box-shadow: inset 0 0 10px rgba(0, 234, 255, 0.1);
    text-shadow: 0 0 5px rgba(0, 234, 255, 0.5);
}

.teclado {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
}

button {
    height: 60px;
    font-size: 20px;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    background-color: rgba(0, 0, 0, 0.5);
    color: #fff;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px rgba(0,0,0,0.3);
}

button:hover {
    background-color: rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 15px rgba(0, 234, 255, 0.5);
    transform: translateY(-2px);
}

button:active {
    transform: translateY(0);
}

.operador {
    color: #ff00de;
    background-color: rgba(20, 0, 20, 0.5);
}

.operador:hover {
    box-shadow: 0 0 15px rgba(255, 0, 222, 0.6);
}

.igual {
    grid-row: span 2;
    height: 100%;
    background-color: rgba(0, 255, 0, 0.1);
    color: #00ff00;
    border: 1px solid rgba(0, 255, 0, 0.2);
}

.igual:hover {
    background-color: rgba(0, 255, 0, 0.2);
    box-shadow: 0 0 20px rgba(0, 255, 0, 0.6);
}

.zero {
    grid-column: span 2;
}

footer {
    position: fixed;
    bottom: 15px;
    color: rgba(255, 255, 255, 0.5);
    font-size: 14px;
    text-shadow: 0 0 5px rgba(0, 234, 255, 0.3);
}