.thumb-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 6px;
    gap: 8px;
}

.thumb-row-top .thumb-btn {
    width: 48px;
    height: 48px;
    font-size: 18px;
}

.thumb-btn {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    border: none;
    font-family: 'Outfit', sans-serif;
    font-size: 22px;
    font-weight: 500;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.1s ease, box-shadow 0.1s ease, background-color 0.15s ease;
    user-select: none;
    padding: 0;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

.thumb-btn:active {
    transform: scale(0.92);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.btn-num {
    background: linear-gradient(145deg, #3a3a3a, #2a2a2a);
}

.btn-num:active {
    background: linear-gradient(145deg, #2a2a2a, #3a3a3a);
}

.btn-op {
    background: linear-gradient(145deg, #ffab40, #ff8f00);
    color: white;
}

.btn-op:active {
    background: linear-gradient(145deg, #ff8f00, #ffab40);
}

.btn-func {
    background: linear-gradient(145deg, #b8b8b8, #9a9a9a);
    color: #1a1a1a;
}

.btn-func:active {
    background: linear-gradient(145deg, #9a9a9a, #b8b8b8);
}

.btn-sci {
    background: linear-gradient(145deg, #5c6bc0, #3f51b5);
    color: white;
    font-size: 16px;
}

.btn-sci:active {
    background: linear-gradient(145deg, #3f51b5, #5c6bc0);
}

.btn-mem {
    background: linear-gradient(145deg, #26a69a, #00897b);
    color: white;
    font-size: 14px;
    font-weight: 600;
}

.btn-mem:active {
    background: linear-gradient(145deg, #00897b, #26a69a);
}

.thumb-hist-item {
    padding: 8px 12px;
    text-align: right;
    color: #aaa;
    font-size: 15px;
    border-bottom: 1px solid #333;
    cursor: pointer;
    transition: background-color 0.15s ease, color 0.15s ease;
    border-radius: 6px;
    margin-bottom: 2px;
}

.thumb-hist-item:hover {
    background-color: #1a1a1a;
}

.thumb-hist-item:active {
    background-color: #2a2a2a;
    color: #fff;
}

.calc-side-panel {
    position: absolute;
    left: 10px;
    bottom: 80px;
    width: 130px;
    display: flex;
    flex-direction: row;
    gap: 8px;
}

.side-panel-column {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.side-btn {
    width: 56px;
    height: 44px;
    border-radius: 12px;
    border: none;
    font-family: 'Outfit', sans-serif;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.1s ease, box-shadow 0.1s ease;
    user-select: none;
    padding: 0;
    box-shadow: 0 3px 6px rgba(0, 0, 0, 0.3);
}

.side-btn:active {
    transform: scale(0.92);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

.memory-indicator {
    position: absolute;
    top: 50px;
    left: 20px;
    color: #4fc3f7;
    font-size: 14px;
    font-weight: 600;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.memory-indicator.active {
    opacity: 1;
}

@media (min-width: 769px) {
    .thumb-btn {
        width: 70px;
        height: 70px;
        font-size: 26px;
    }

    .thumb-row-top .thumb-btn {
        width: 56px;
        height: 56px;
        font-size: 20px;
    }

    .side-btn {
        width: 64px;
        height: 50px;
        font-size: 16px;
    }

    .calc-side-panel {
        left: 20px;
        bottom: 100px;
    }
}