body {
    font-family: Arial, sans-serif;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    background-color: #f5f5f5;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}
.calculator {
    background-color: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    flex: 1;
}
h1 {
    color: #2c3e50;
    text-align: center;
    font-size: 35px;
    margin-bottom: 30px;
    font-weight: 700;
    letter-spacing: -0.5px;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.05);
    padding-bottom: 5px;
}

.calc-row {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 20px;
    padding: 15px;
    background-color: #f9f9f9;
    border-radius: 8px;
    border: 1px solid #e0e0e0;
    flex-wrap: wrap;
}
.calc-formula {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}
input {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 6px;
    width: 80px;
    text-align: center;
    font-size: 16px;
}
select {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 16px;
}
button {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
    min-width: 120px;
    transition: background-color 0.3s;
}
button:hover {
    background-color: #45a049;
}
.result {
    flex: 1;
    min-width: 200px;
    padding: 12px;
    background-color: #e9f7ef;
    border-radius: 6px;
    font-size: 16px;
    font-weight: bold;
    text-align: center;
}
footer {
text-align: center;
margin-top: 60px;
padding-top: 20px;
border-top: 1px solid #eee;
color: #777;
}

.footer-link {
color: var(--primary-color);
text-decoration: none;
font-weight: 600;
}

.footer-link:hover {
text-decoration: none;
opacity: 0.8;
}
@media (max-width: 600px) {
    .calc-row {
        flex-direction: column;
        align-items: flex-start;
    }
    .calc-formula {
        width: 100%;
        margin-bottom: 10px;
    }
    button, .result {
        width: 100%;
    }
}