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

body {
    font-family: 'Roboto', sans-serif;
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
}

header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    padding: 15px 20px;
    position: relative;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
}

header h1 {
    font-size: 24px;
    font-weight: 500;
    color: #333;
}

header h1 a {
    text-decoration: none;
    color: #333;
    font-size: 24px;
    font-weight: 500;
}

.hamburger {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #333;
    padding: 5px;
    z-index: 100;
}

.main-nav {
    display: flex;
    transition: all 0.3s ease-in-out;
}

.main-nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
    margin: 0;
    padding: 0;
}

.main-nav ul li a {
    text-decoration: none;
    color: #007BFF;
    font-weight: 500;
    padding: 5px 10px;
    border-radius: 4px;
    transition: all 0.3s;
}

.main-nav ul li a:hover,
.main-nav ul li a.active {
    color: #0056b3;
    background-color: #f0f4ff;
}


.calculator-section {
    max-width: 1200px;
    margin: 20px auto;
    padding: 20px;
}

.calculator {
    background: #fff;
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    max-width: 500px;
    margin: 0 auto;
}

.calculator h2 {
    text-align: center;
    font-size: 24px;
    margin-bottom: 20px;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    font-size: 16px;
    margin-bottom: 5px;
    display: block;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 10px;
    font-size: 16px;
    border: 1px solid #ddd;
    border-radius: 4px;
}

button {
    background-color: #007BFF;
    color: #fff;
    padding: 10px 15px;
    font-size: 16px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    width: 100%;
    margin-top: 15px;
}

button:hover {
    background-color: #0056b3;
}

.result {
    margin-top: 20px;
    font-size: 18px;
    font-weight: 500;
}

footer {
    text-align: center;
    padding: 30px 20px;
    background: #fff;
    box-shadow: 0 -2px 4px rgba(0, 0, 0, 0.1);
    margin-top: 20px;
    font-size: 14px;
    color: #333;
}

footer .footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    text-align: left;
}

footer .footer-container .footer-section {
    flex: 1;
    margin: 10px;
    min-width: 200px;
}

footer .footer-container .footer-section h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 15px;
}

footer .footer-container .footer-section ul {
    list-style-type: none;
    padding: 0;
}

footer .footer-container .footer-section ul li {
    margin-bottom: 10px;
}

footer .footer-container .footer-section ul li a {
    text-decoration: none;
    color: #007BFF;
    font-weight: 500;
    transition: color 0.3s;
}

footer .footer-container .footer-section ul li a:hover {
    color: #0056b3;
}

footer .footer-container .footer-socials {
    display: flex;
    align-items: center;
    gap: 15px;
}

footer .footer-container .footer-socials a {
    text-decoration: none;
    color: #333;
    font-size: 20px;
    transition: color 0.3s;
}

footer .footer-container .footer-socials a:hover {
    color: #007BFF;
}

footer .footer-bottom {
    margin-top: 30px;
    font-size: 12px;
    color: #777;
}

@media (max-width: 768px) {
    .hamburger {
        display: block;
    }

    .main-nav {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: #fff;
        box-shadow: 0 2px 4px rgba(0,0,0,0.1);
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease-in-out;
    }

    .main-nav.active {
        max-height: 500px;
    }

    .main-nav ul {
        flex-direction: column;
        gap: 0;
        padding: 10px 20px;
        width: 100%;
    }

    .main-nav ul li {
        margin: 5px 0;
    }

    .main-nav ul li a {
        display: block;
        padding: 12px 15px;
    }

    header {
        padding: 10px 15px;
    }

    header h1 a {
        font-size: 20px;
    }

    footer .footer-container {
        flex-direction: column;
        align-items: center;
    }

    footer .footer-container .footer-section {
        margin-bottom: 20px;
    }

    footer .footer-socials {
        justify-content: center;
    }
}