body {
    background: #f5f5f7;
    color: #222;
    font-family: 'Segoe UI', Arial, sans-serif;
    margin: 0;
    padding: 0;
    min-height: 100vh;
}

.calculator {
    background: #fff;
    border-radius: 32px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.10);
    padding: 24px 16px;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 240px;
}
.calc-display {
    width: 100%;
    font-size: 1.6rem;
    padding: 12px 10px;
    border-radius: 18px;
    border: none;
    background: #f8f8fa;
    color: #222;
    margin-bottom: 24px;
    text-align: right;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}
.calc-buttons {
    display: grid;
    grid-template-columns: repeat(4, 48px);
    gap: 12px;
}

.calc-buttons-left {
    display: grid;
    grid-template-columns: repeat(2, 48px);
    gap: 12px;
    align-content: flex-start;
}
/* Einheitliches Button-Styling für beide Bereiche */
.calc-buttons button,
.calc-buttons-left button {
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 18px;
    background: linear-gradient(90deg, #e5e9f2 0%, #fff 100%);
    color: #222;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    padding: 10px 0;
    cursor: pointer;
    transition: background 0.2s, box-shadow 0.2s, transform 0.2s;
}
.calc-buttons button:hover,
.calc-buttons-left button:hover {
    background: linear-gradient(90deg, #0071e3 0%, #005bb5 100%);
    color: #fff;
    box-shadow: 0 8px 32px rgba(0,0,0,0.18);
    transform: scale(1.05);
}
.calc-buttons button:last-child {
    grid-column: span 4;
}