body {
    margin: 0;
    font-family: Arial, sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* HEADER */
header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px 25px;
    background: #f5f5f5;
    border-bottom: 1px solid #ddd;
}

.logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: #333;
}

.logo img {
    /* height: 40px; */
    margin-right: 10px;
}

.logo span {
    font-size: 20px;
    font-weight: bold;
}

nav {
    display: flex;
    gap: 20px;
}

nav a {
    text-decoration: none;
    color: #333;
    font-weight: 600;
}

nav a:hover {
    color: #4CAF50;
}

/* MOBILE MENU */
.menu-btn {
    display: none;
    font-size: 24px;
    cursor: pointer;
}

main {
    flex: 1;
    padding: 40px;
}

footer {
    text-align: center;
    padding: 15px;
    background: #f5f5f5;
    font-size: 14px;
    color: #666;
}

@media (max-width: 768px) {
    nav {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 70px;
        right: 20px;
        background: #fff;
        border: 1px solid #ddd;
        padding: 15px;
    }

    nav.active {
        display: flex;
    }

    .menu-btn {
        display: block;
    }
}

/* Кнопка возврата наверх */
#backToTop {
    position: fixed;
    right: 20px;
    bottom: 20px;
    width: 45px;
    height: 45px;
    border: none;
    border-radius: 50%;
    background: #7bac19;
    color: #fff;
    font-size: 22px;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    z-index: 1000;
}

#backToTop:hover {
    background: #43a047;
}