/* Back to Top Button */
.back-to-top-btn {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 100;
    background-color: #333;
    color: #fff;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    font-size: 24px;
    cursor: pointer;
    transition: opacity 0.3s ease, visibility 0.3s ease, bottom 0.3s ease-in-out;
    opacity: 0;
    visibility: hidden;
    line-height: 50px;
    text-align: center;
    text-decoration: none;
    font-family: 'Inter', sans-serif;
}
.back-to-top-btn.visible {
    opacity: 1;
    visibility: visible;
}
.back-to-top-btn:hover {
    background-color: #555;
    text-decoration: none;
}

/* Basic Reset & Typography */
h1{
    font-weight: 100;
    font-size: 22px;
}
h2 {
    font-size: 1.8em;
    margin-top: 0;
    margin-bottom: 20px;
    color: #333;
    border-bottom: none;
}
.container {
    max-width: 1080px;
    margin: 0 auto;
}
a {
    color: #2196f3;
    text-decoration: underline;
}
a:hover {
    text-decoration: underline;
}
header a {
    color: #333;
    text-decoration: none;
}
header a:hover {
    text-decoration: none;
}

/* --- Footer --- */
footer {
    font-family: 'Inter', sans-serif;
    background-color: #222;
    color: #ccc;
    text-align: center;
    padding: 40px 20px;
    font-size: 0.85em;
}
footer a {
    color: #fff;
    margin: 0 8px;
}