.age-calculator {
    max-width: 600px;
    margin: 20px auto;
    padding: 30px;
    background: #ffffff;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.calculator-header h3 {
    margin: 0 0 25px 0;
    color: #2c3e50;
    font-size: 1.8em;
    text-align: center;
}

.input-group {
    margin-bottom: 25px;
}

.input-group label {
    display: block;
    margin-bottom: 10px;
    color: #34495e;
    font-weight: 600;
    font-size: 1.1em;
}

#birthDateTime {
    width: 100%;
    padding: 12px;
    border: 2px solid #3498db;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s;
}

#birthDateTime:focus {
    border-color: #2980b9;
    outline: none;
}

button#calculateAge {
    width: 100%;
    padding: 15px;
    background: #3498db;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.1em;
    transition: background 0.3s;
    margin: 20px 0;
}

button#calculateAge:hover {
    background: #2980b9;
}

.results {
    margin-top: 25px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 8px;
    display: none;
}

.results h4 {
    text-align: center;
    margin: 0 0 20px 0;
    color: #2c3e50;
    font-size: 1.4em;
}

.result-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
}

.result-item {
    text-align: center;
    padding: 15px;
    background: #ffffff;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.result-item span {
    display: block;
}

.result-item span:first-child {
    color: #7f8c8d;
    font-size: 0.9em;
    margin-bottom: 5px;
}

.result-item span:last-child {
    color: #2c3e50;
    font-size: 1.4em;
    font-weight: bold;
}

.error-message {
    color: #e74c3c;
    margin-top: 15px;
    text-align: center;
    font-weight: 500;
    display: none;
}

.fa-birthday-cake, .fa-calendar-alt {
    margin-right: 8px;
}

@media (max-width: 480px) {
    .result-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .age-calculator {
        padding: 20px;
    }
}