* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

h1 {
    margin-bottom: 10px;
    color: #2c3e50;
}

p {
    margin-bottom: 20px;
}

.calculator-card, .results-card {
    background-color: white;
    border-radius: 8px;
    padding: 25px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
}

input {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
}

.calculate-button {
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 4px;
    padding: 12px 20px;
    font-size: 16px;
    cursor: pointer;
    width: 100%;
    transition: background-color 0.3s;
}

.calculate-button:hover {
    background-color: #2980b9;
}

.results-card {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid #eee;
}

.result-label {
    font-weight: 600;
}

.result-value {
    font-weight: 700;
}

.positive {
    color: #27ae60;
}

.negative {
    color: #e74c3c;
}

.error-message {
    background-color: #f8d7da;
    color: #721c24;
    padding: 15px;
    border-radius: 4px;
    margin-bottom: 20px;
}

.hidden {
    display: none;
}