* {
    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 {
    max-width: 600px;
    width: 100%;
}

h1 {
    text-align: center;
    color: white;
    margin-bottom: 30px;
    font-size: 2rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.calculator {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    margin-bottom: 20px;
}

.section {
    margin-bottom: 30px;
    padding-bottom: 30px;
    border-bottom: 2px solid #f0f0f0;
}

.section:last-of-type {
    margin-bottom: 0;
}

.dpi-section {
    margin-bottom: 30px;
    padding-bottom: 30px;
    border-bottom: 2px solid #f0f0f0;
}

h2 {
    color: #333;
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.input-group {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
}

label {
    font-weight: bold;
    color: #555;
    min-width: 90px;
}

input[type="number"] {
    flex: 1;
    padding: 12px 15px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

input[type="number"]:focus {
    outline: none;
    border-color: #667eea;
}

.result {
    background: #f8f9fa;
    padding: 15px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.result-label {
    font-weight: bold;
    color: #555;
}

.result span:last-child {
    color: #667eea;
    font-size: 1.2rem;
    font-weight: bold;
}

.result + .result {
    margin-top: 10px;
}


.dpi-buttons {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.dpi-btn {
    flex: 1;
    min-width: 130px;
    padding: 12px 20px;
    border: 2px solid #667eea;
    background: white;
    color: #667eea;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 500;
}

.dpi-btn:hover {
    background: #f0f2ff;
}

.dpi-btn.active {
    background: #667eea;
    color: white;
}

.current-dpi {
    text-align: center;
    padding: 10px;
    background: #f8f9fa;
    border-radius: 8px;
    color: #555;
    font-weight: 500;
}

#current-dpi-value {
    color: #667eea;
    font-weight: bold;
}

.info {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    padding: 20px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.info h3 {
    color: #333;
    margin-bottom: 10px;
}

.info p {
    color: #555;
    margin: 5px 0;
    font-family: 'Courier New', monospace;
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.5rem;
    }

    .calculator {
        padding: 20px;
    }

    .dpi-buttons {
        flex-direction: column;
    }

    .dpi-btn {
        width: 100%;
    }
}