body {
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: black;
    background-image: 
        linear-gradient(rgba(245, 94, 94, 0.2) 1px, transparent 1px),
        linear-gradient(90deg, rgba(245, 94, 94, 0.2) 1px, transparent 1px);
    background-size: 67px 67px; 
    background-attachment: fixed;
}

.cal-container {
    width: 400px;
    min-height: 450px;
    height: auto;
    background-color: #201c1cc8;
    background-image: linear-gradient(315deg , #201c1cc8 0%, #600d0da8 74%);
    border-radius: 20px 0px 20px 0px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.2);
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
}

.cal-display{
    width: 350px;
    min-height: 80px;
    height: auto;
    word-wrap: break-word;
    background-color: #130e0edf;
    border: 2px solid #600d0d;
    border-radius: 12px;
    font-size: 52px;
    color: #c74242;
    font-weight: bold;
    box-shadow: inset 0 0 15px rgba(240, 7, 7, 0.5);
}

.cal-buttons{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    width: 350px;
    height: 300px;
    margin-top: 20px;
}

.num-btn, .opr-btn{
    background-color:#121212;
    color:#c74242;
    border-top: 1px solid #333;
    border-left: 1px solid #222;
    border-right: 1px solid #111;
    border-bottom: 5px solid #000;
    font-size: 24px;
    font-weight: bold;
    border-radius: 8px;
    box-shadow: 
        inset 0 2px 3px rgba(255, 255, 255, 0.1), /* Top edge light */
        0 5px 10px rgba(0, 0, 0, 0.8);
    transition: transform 0.3s, box-shadow 0.2s;
}

.num-btn:hover, .opr-btn:hover{
    cursor: pointer;
    transform: scale(1.05);
    box-shadow: 2px 4px 14px rgba(187, 28, 28, 0.7);
}

.num-btn:active, .opr-btn:active{
    transform: scale(0.95);
    box-shadow: inset 0 0 10px rgba(187, 28, 28, 0.7);
}

.unique-btn{
    background-color: #130101dc;
    color: #c74242;
    border-top: 1px solid #333;
    border-left: 1px solid #222;
    border-right: 1px solid #111;
    border-bottom: 5px solid #000;
    font-size: 30px;
    font-weight: bold;
    border-radius: 8px;
    box-shadow: 
        inset 0 2px 3px rgba(131, 50, 50, 0.1), /* Top edge light */
        0 5px 10px rgba(0, 0, 0, 0.8);
    transition: transform 0.3s, box-shadow 0.2s;
}

.unique-btn:hover{
    cursor: pointer;
    transform: scale(1.05);
    box-shadow: 3px 5px 13px rgba(187, 28, 28, 0.7),
                3px 5px 27px rgba(187, 28, 28, 0.7);
}

.unique-btn:active{
    transform: scale(0.95);
    box-shadow: inset 0 0 10px rgba(187, 28, 28, 0.7);
}