.percentage-calculator-container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem;
    background: linear-gradient(145deg, #f8f9fa 0%, #e9ecef 100%);
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    font-family: 'Segoe UI', sans-serif;
}

.calculator-header {
    text-align: center;
    margin-bottom: 2rem;
}

.calculator-header h2 {
    font-size: 2rem;
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.calculator-header p {
    font-size: 1rem;
    color: #7f8c8d;
}

.input-group {
    margin-bottom: 1.5rem;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #2c3e50;
}

.input-field {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid #dee2e6;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.input-field:focus {
    border-color: #4dabf7;
    box-shadow: 0 0 0 3px rgba(77, 171, 247, 0.1);
    outline: none;
}

.controls {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    flex-wrap: wrap;
}

.btn {
    padding: 0.8rem 1.5rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
}

.btn-primary {
    background: #4dabf7;
    color: white;
}

.btn-danger {
    background: #ff6b6b;
    color: white;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.result-container {
    margin-top: 2rem;
    padding: 1.5rem;
    background: white;
    border-radius: 8px;
    animation: fadeIn 0.5s ease-out;
}

.result-container h3 {
    font-size: 1.5rem;
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.error-message {
    color: #ff6b6b;
    margin: 0.5rem 0;
    display: none;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@media (max-width: 768px) {
    .percentage-calculator-container {
        padding: 1rem;
        margin: 1rem;
    }

    .controls {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}