style.css

body {
    font-family: 'Lucida Console', Courier, monospace;
    background-color: #f0f0f0;
    margin: 0;
    padding: 0;
}

.title {
    text-align: center;
    margin-top: 20px;
    margin-bottom: 30px;
}

.title h1 {
    font-size: 2.5em;
    color: #6A0DAD;
    text-shadow:2px 3px 12px#051b01;
}

.title h2{
    font-size: 2em;
    color:#008080;
    text-shadow:2px 3px 12px #30190f;
}

.calculator {
    max-width: fit-content;
    margin: 50px auto;
    padding: 20px;
    border: 2px solid #1b1d18;
    border-radius: 12px;
    box-shadow: 2px 4px 12px #1b1d18;
    background-color: #C0C0C0;
}

.display {
    display: flex;
    justify-content:flex-end;
    width: 90%;
    height: 40px;
    padding: 10px;
    margin-bottom: 20px;
    background-color: #140000;
    border: solid 2px #49111c;
    border-radius: 12px;
    overflow: hidden;
}

#output {
    font-family: 'Courier New', Courier, monospace;
    margin: 10px;
    color: #ff0000;
    text-shadow: 6px 0px 5px #ff0000;
    font-size: 1.2em;
}

.buttons {
    display:grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

button {
    width: 100%;
    padding: 20px;
    font-size: 1em;
    cursor: pointer;
    border: 2px solid #000;
    border-radius: 6px; 
    background-color: #333;
    color: #f1f1f1;
    box-shadow: 0 0 5px black;
}

button:hover {
    background-color: #6A0DAD;
}

.operator, .equals {
    background-color: #39FF14;
    color: #000
}

.clear {
    background-color: #a00000;
}

.instructions {
    max-width: 600px;
    margin: 30px auto;
    padding: 20px;
    background-color: #c0c0c0;
    border: 2px solid #cccccc50;
    border-radius: 12px;
    box-shadow: 2px 6px 10px #00000075;
}

.instructions h2 {
    color: #6A0DAD;
}

.instructions ul {
    list-style-type: disc;
    padding-left: 20px;
}

.instructions li {
    margin-bottom: 10px;
}

.instructions h3 {
    color: #6A0DAD;
    margin-top: 20px;
}

.instructions .text {
    margin-bottom: 20px;
    line-height: 1.4;
    font-size: 0.95em;
}

@media only screen and (max-width: 600px) {
    .calculator {
        max-width: 90%;
    }
}