* {
    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;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    padding: 40px;
    max-width: 500px;
    width: 100%;
}

h1 {
    color: #333;
    margin-bottom: 15px;
    font-size: 28px;
    text-align: center;
}

.description {
    color: #666;
    text-align: center;
    margin-bottom: 30px;
    font-size: 14px;
    line-height: 1.5;
}

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

label {
    display: block;
    color: #333;
    font-weight: 600;
    margin-bottom: 10px;
    font-size: 16px;
}

input[type="number"] {
    width: 100%;
    padding: 14px 16px;
    font-size: 16px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    transition: all 0.3s ease;
    color: #333;
}

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

input[type="number"]::placeholder {
    color: #999;
}

.results {
    background: #f5f5f5;
    border-radius: 8px;
    padding: 25px;
    margin-top: 35px;
    border-left: 4px solid #667eea;
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.result-item:last-child {
    margin-bottom: 0;
}

.result-label {
    color: #666;
    font-weight: 600;
    font-size: 15px;
}

.result-value {
    color: #667eea;
    font-size: 24px;
    font-weight: 700;
}

.section-title {
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: #999;
    font-weight: 600;
    margin-bottom: 20px;
    margin-top: 10px;
    padding-bottom: 8px;
    border-bottom: 1px solid #eee;
}

.form-row {
    display: flex;
    gap: 16px;
}

.form-row .form-group {
    flex: 1;
}

input[type="text"],
input[type="date"] {
    width: 100%;
    padding: 14px 16px;
    font-size: 16px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    transition: all 0.3s ease;
    color: #333;
    font-family: inherit;
}

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

input[type="text"]::placeholder {
    color: #999;
}

.optional {
    font-weight: 400;
    color: #999;
    font-size: 13px;
}

.btn-faktura {
    display: block;
    width: 100%;
    margin-top: 24px;
    padding: 16px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 17px;
    font-weight: 700;
    cursor: pointer;
    transition: opacity 0.2s ease;
    font-family: inherit;
}

.btn-faktura:hover {
    opacity: 0.9;
}

/* Mobile responsive */
@media (max-width: 600px) {
    .container {
        padding: 25px;
    }

    h1 {
        font-size: 24px;
    }

    .description {
        font-size: 13px;
    }

    input[type="number"] {
        font-size: 16px;
        padding: 12px 14px;
    }

    .result-value {
        font-size: 20px;
    }
}