body {
    background: #000;
    font-family: 'Inter', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.life-calc {
    width: 900px;
    background: #F9FAFF;
    border-radius: 28px;
    padding: 28px;
    box-shadow: 0 30px 80px rgba(0, 0, 0, 0.15);
}

.display {
    background: linear-gradient(135deg, #6C756B, #93ACB5);
    color: white;
    border-radius: 20px;
    padding: 18px;
    margin-bottom: 24px;
}

.mode-name {
    font-size: 0.9rem;
    opacity: 0.7;
}

#screen {
    width: 100%;
    font-size: 2rem;
    background: transparent;
    border: none;
    color: white;
    outline: none;
}

.calculator-body {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 20px;
}

.keys {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
}


.keys button,
.key {
    padding: 20px;
    font-size: 1.2rem;
    border: none;
    border-radius: 18px;
    cursor: pointer;
    background: #96C5F7;
    color: #000;
    font-weight: 600;
    transition: all 0.15s ease;
}

.keys button:hover,
.key:hover {
    background: #A9D3FF;
    transform: translateY(-2px);
}

.keys button:active,
.key:active {
    transform: scale(0.96);
}


.op {
    background: #96C5F7;
}


.zero {
    grid-column: span 2;
}

.bottom-row {
    grid-column: span 4;
    display: grid;
    grid-template-columns: 1fr 1fr 2fr;
    gap: 14px;
    margin-top: 6px;
}


.bottom-row .key {
    font-size: 1.2rem;
}

.bottom-row .equal {
    background: #111;
    color: #fff;
    font-size: 1.6rem;
    font-weight: 700;
}

.bottom-row .equal:hover {
    background: #000;
}


.modes {
    background: #b1ddf1;
    border-radius: 20px;
    padding: 18px;
}

.modes h3 {
    margin-top: 0;
}

.modes button {
    width: 100%;
    margin-bottom: 10px;
    padding: 12px;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    background: white;
    font-weight: 500;
}

.modes button:hover {
    background: #e6f2fb;
}

.hint {
    font-size: 0.8rem;
    color: #555;
    margin-top: 10px;
}


.result-box {
    margin-top: 20px;
    padding: 14px;
    border-radius: 14px;
    background: #f1f3f6;
    font-size: 1rem;
}

.prank-popup {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 999;
}

.prank-box {
    background: #F9FAFF;
    padding: 28px 36px;
    border-radius: 24px;
    text-align: center;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    animation: popIn 0.25s ease;
}

.prank-box h2 {
    margin-top: 0;
}

.prank-box button {
    margin-top: 20px;
    padding: 10px 24px;
    border: none;
    border-radius: 14px;
    background: #96C5F7;
    font-size: 1rem;
    cursor: pointer;
}

@keyframes popIn {
    from {
        transform: scale(0.9);
        opacity: 0;
    }

    to {
        transform: scale(1);
        opacity: 1;
    }
}

@media (max-width: 768px) {
    body {
        align-items: flex-start;
        padding: 16px;
    }

    .life-calc {
        width: 100%;
        padding: 18px;
        border-radius: 22px;
    }

    .calculator-body {
        grid-template-columns: 1fr;
    }

    .modes {
        margin-top: 20px;
    }

    .keys button,
    .bottom-row .key {
        padding: 20px;
        font-size: 1.1rem;
    }
}