/* Calculator Tool Styles */
#calculator-app {
    max-width: 400px;
    margin: 0 auto;
    background: #fff;
    border: 2px solid #e53935;
    border-radius: 16px;
    box-shadow: 0 2px 16px rgba(229,57,53,0.07);
    padding: 2rem 1.5rem 1.5rem 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 2.5rem;
}
.calc-display {
    width: 100%;
    min-height: 3.2rem;
    background: #f9fafb;
    border: 1.5px solid #e53935;
    border-radius: 8px;
    font-size: 2.1rem;
    font-family: 'Inter', monospace;
    color: #222;
    text-align: right;
    padding: 0.7rem 1rem;
    margin-bottom: 1.5rem;
    box-sizing: border-box;
    word-break: break-all;
    letter-spacing: 1px;
}
.calc-buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.7rem;
    width: 100%;
}
.calc-btn {
    font-size: 1.25rem;
    padding: 0.9rem 0.2rem;
    border: 1.5px solid #e0e0e0;
    border-radius: 8px;
    background: #fff;
    color: #e53935;
    font-family: 'Inter', monospace;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, color 0.2s, border 0.2s;
    outline: none;
    box-shadow: 0 1px 4px rgba(229,57,53,0.04);
}
.calc-btn:hover, .calc-btn:focus {
    background: #ffeaea;
    color: #b71c1c;
    border-color: #e53935;
}
.calc-btn.op {
    background: #fff5f5;
    color: #b71c1c;
    border-color: #e53935;
}
.calc-btn.eq {
    background: linear-gradient(135deg, #e53935 0%, #ff7043 100%);
    color: #fff;
    border-color: #e53935;
    font-size: 1.35rem;
}
.calc-btn.sci {
    background: #f9fafb;
    color: #e53935;
    border-color: #e0e0e0;
    font-size: 1.1rem;
}
@media (max-width: 600px) {
    #calculator-app {
        padding: 1.2rem 0.5rem 1.2rem 0.5rem;
    }
    .calc-display {
        font-size: 1.3rem;
        padding: 0.5rem 0.7rem;
    }
    .calc-btn {
        font-size: 1rem;
        padding: 0.7rem 0.1rem;
    }
}