@font-face {
    font-family: 'Digital-7';
    src: url('../fonts/digital-7.otf') format('opentype');
    font-weight: normal;
    font-style: normal;
}

#calculator-overlay {
    position: fixed;
    right: 20px;
    width: 260px;
    background: #111;
    border-radius: 16px;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.5);
    z-index: 10001;
    display: none;
    overflow: hidden;
    font-family: 'Digital-7', monospace;
}

#calculator-header {
    background-color: #333;
    color: white;
    padding: 8px 12px;
    font-size: 14px;
    cursor: move;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

#calculator-display {
    background: #b5c7a5;
    color: #000;
    font-size: 40px;
    text-align: right;
    line-height: 36px;
    padding-left: 12px;
    padding-right: 12px;
    padding-top:2px;
    height: 50px;
    box-sizing: border-box;
    font-family: 'Digital-7', monospace !important;
}

.calculator-keys {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
    padding: 12px;
    background: #222;
}

.calculator-keys button {
    padding: 12px;
    font-size: 16px;
    border: none;
    border-radius: 10px;
    font-family: Arial, sans-serif;
    cursor: pointer;
}

button.main {
    background-color: var(--main-colour, #00A3F9);
    color: white;
}

button.function {
    background-color: #444;
    color: white;
}

button.number {
    background-color: #888;
    color: white;
}

#calculator-fab {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: var(--main-colour, #00A3F9);
    color: white;
    border: none;
    border-radius: 50%;
    width: 56px;
    height: 56px;
    font-size: 24px;
    cursor: pointer;
    z-index: 10000;
}