header {
    padding: 20px;
    text-align: center;
    position: relative;
    border-bottom: 1px solid #fff;
}

.header-circle {
    position: absolute;
    bottom: -60px;
    left: 20px;
    width: 120px;
    height: 120px;
    background-image: url('../assets/images/profile.webp');
    background-size: cover;
    background-position: center;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.8);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.6);
}

header h1 {
    font-size: 2.5em;
}

header nav {
    margin-top: 10px;
}

header nav a {
    margin: 0 15px;
    color: #fff;
    font-size: 1.2em;
}

header nav a:hover {
    color: #a9a9a9;
}

@media (max-width: 768px) {
    header {
        padding-bottom: 40px;
    }
    .header-circle {
        width: 40px;
        height: 40px;
        bottom: -35px;
        left: 50%;
    }
}