/* --- SIDEBAR --- */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 80px;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;

    gap: 8px;
    background: #fff;
    border-right: 1px solid #ddd;
    z-index: 10;
}

.sidebar a {
    text-decoration: none;
    color: #000;
    font-size: 18px;
    letter-spacing: 0.5px;
    margin: 10px 0;
    transition: opacity 0.2s ease;
}

.sidebar a:hover {
    opacity: 0.5;
}

.container {
    margin-left: 100px;
    padding: 85px;
    flex: 1;
    max-width: 900px;
}

.container img {
    width: 100%;
    height: auto;
    display: block;
}

#toggleImage {
    max-width: 1000px;
    width: 90vw;
    /* responsive: 70% of viewport width on small screens */
    height: auto;
    display: block;
    margin: 20px auto;
}

/* center heading on week5 (targets the non-standard <text> wrapper used in week5.html) */
text h1 {
    text-align: center;
    margin: 0.5rem auto;
    /* add space from top so heading doesn't sit under the fixed sidebar/header */
    padding-top: 85px;
}

/* ensure SVG arrows in the sidebar are visible and sized (shared) */
.sidebar a {
    padding: 6px;
}

.sidebar a svg {
    width: 20px;
    height: 20px;
    display: block;
}

.sidebar a svg path {
    stroke: currentColor;
}