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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    padding: 40px;
    max-width: 600px;
    width: 100%;
}

h1 {
    color: #333;
    text-align: center;
    margin-bottom: 30px;
    font-size: 28px;
}

h2 {
    color: #667eea;
    margin-bottom: 20px;
    font-size: 22px;
}

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

label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 600;
    font-size: 14px;
}

input[type="number"],
select {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s ease;
}

input[type="number"]:focus,
select:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.calculate-btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    margin-top: 10px;
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

.calculate-btn:active {
    transform: translateY(0);
}

.results {
    margin-top: 30px;
    padding-top: 30px;
    border-top: 2px solid #e0e0e0;
}

.results.hidden {
    display: none;
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 8px;
    margin-bottom: 12px;
}

.result-item .label {
    color: #555;
    font-weight: 600;
    font-size: 14px;
}

.result-item .value {
    color: #333;
    font-size: 18px;
    font-weight: 700;
}

.result-item .value.highlight {
    color: #667eea;
    font-size: 20px;
}

@media (max-width: 640px) {
    .container {
        padding: 25px;
    }

    h1 {
        font-size: 24px;
    }

    .result-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
}