body {
    font-family: Arial, sans-serif;
    background-color: #001122;
    color: #ffffff;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    display: flex;
    width: 100%;
    max-width: 1200px;
    height: 100vh;
}

.calculator {
    flex: 1;
    background-color: #002244;
    padding: 20px;
    border-right: 2px solid #004466;
    display: flex;
    flex-direction: column;
}

.mode-selector {
    display: flex;
    margin-bottom: 20px;
}

.mode-btn {
    flex: 1;
    padding: 10px;
    background-color: #004466;
    color: #ffffff;
    border: none;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s;
}

.mode-btn.active {
    background-color: #006688;
}

.mode-btn:hover {
    background-color: #005577;
}

.display {
    margin-bottom: 20px;
}

#calc-display {
    width: 100%;
    padding: 15px;
    font-size: 24px;
    background-color: #001122;
    color: #ffffff;
    border: 2px solid #004466;
    border-radius: 5px;
    text-align: right;
}

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

.btn {
    padding: 20px;
    font-size: 20px;
    background-color: #004466;
    color: #ffffff;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.2s;
}

.btn:hover {
    background-color: #005577;
    transform: scale(1.05);
}

.btn:active {
    background-color: #006688;
    transform: scale(0.95);
}

.btn.number:active {
    animation: numberPress 0.5s ease;
}

@keyframes numberPress {
    0% { background-color: #004466; box-shadow: 0 0 0 0 rgba(0, 255, 255, 0.7); }
    25% { background-color: #00ffff; box-shadow: 0 0 10px 5px rgba(0, 255, 255, 0.7); }
    50% { background-color: #ff00ff; box-shadow: 0 0 10px 5px rgba(255, 0, 255, 0.7); }
    75% { background-color: #ffff00; box-shadow: 0 0 10px 5px rgba(255, 255, 0, 0.7); }
    100% { background-color: #004466; box-shadow: 0 0 0 0 rgba(0, 255, 255, 0.7); }
}

.right-panel {
    flex: 1;
    background-color: #001122;
    padding: 20px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    transform: scaleY(-1);
}

.illustration {
    max-width: 100%;
    max-height: 60%;
    margin-bottom: 20px;
}

.message {
    text-align: center;
    font-size: 24px;
}

.message p {
    margin: 10px 0;
}