.background-overlay {
    height: 100vh;
    width: 100vW;
    position: fixed;
    z-index: -1;
    background: radial-gradient(circle at 20% 80%, rgba(36, 52, 121, 0.4) 0%, transparent 50%), radial-gradient(circle at 80% 20%, rgba(36, 131, 160, 0.3) 0%, transparent 40%), linear-gradient(135deg, #0a0a0a 0%, #1a1a2e 100%);
}

.sidebar-toggle {
    position: fixed;
    inset: 20px auto auto 20px;
    background: white;
    border: none;
    width: 50px;
    height: 50px;
    color: black;
    font-size: 24px;
    border-radius: 50%;
    z-index: 1000;
}

.sidebar-toggle .icon {
    transition: all 0.3s;
    display: inline-block;
    margin-top: 0px;
}

.sidebar-toggle.hidden .icon {
    transform: rotate(180deg);
    margin-top: 3px;
}

.sidebar-toggle:hover {
    cursor: pointer;
}

.left.animate,
.right.animate {
    transition: all 0.3s;
}

.left {
    position: fixed;
    inset: 0 auto 0 0;
    width: 250px;
    padding: 80px 20px 20px;
    background-color: rgb(56 55 78);
    color: white;
    transform: translateX(0);
    z-index: 800;
}

.left-show {
    transform: translateX(-100%);
}

.left .home-button {
    position: absolute;
    inset: 20px 20px auto auto;
    background: white;
    border: none;
    width: 50px;
    height: 50px;
    font-size: 24px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.left .home-button img {
    height: 70%;
    width: 70%;
}

.left .title {
    font-size: 24px;
    font-weight: 700;
    border-bottom: 2px solid white;
    padding-bottom: 10px;
    margin-bottom: 20px;
}

.modules {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.modules a {
    position: relative;
    color: black;
    padding: 10px 25px 10px 20px;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
}

.modules .active {
    background: #ffff94;
}

.modules .completed {
    position: absolute;
    inset: 0 5px auto auto;
    width: 20px;
    height: 100%;
}

.modules .completed .check {
    width: 100%;
    height: 100%;
}

.right {
    width: 100%;
    display: flex;
    justify-content: center;
    flex-direction: column;
}

.right .title {
    font-size: 32px;
    font-weight: 700;
    color: white;
}

.with-sidebar {
    padding: 50px calc(10vw) 50px 300px;
}

.without-sidebar {
    padding: 50px calc(10vw);
}

.content-wrapper {
    position: relative;
    display: flex;
    justify-content: center;
    width: 100%;
    background-color: rgb(56 55 78);
    border-radius: 10px;
}

/* Paragraphs */
.content p {
    line-height: 1.6;      /* airy spacing */
    margin-bottom: 1em;    /* space after paragraph */
}

/* Headings */
.content h1 {
    line-height: 1.2;
    margin-bottom: 0.6em;
}

.content h2 {
    line-height: 1.25;
    margin-bottom: 0.6em;
}

.content h3 {
    line-height: 1.3;
    margin-bottom: 0.5em;
}

.content h4 {
    line-height: 1.35;     /* slightly more than h3 for readability */
    margin-bottom: 0.5em;
    margin-top: 0.5rem;
}

.content h5 {
    line-height: 1.4;
    margin-bottom: 0.4em;
}

.content h6 {
    line-height: 1.45;
    margin-bottom: 0.4em;
}

/* Optional: lists */
.content ul, .content ol {
    line-height: 1.5;
    margin-bottom: 1em;
    margin-left: 1.3rem;
}


.checkmark {
    position: absolute;
    display: flex;
    justify-content: center;
    align-items: center;
    inset: 20px 20px auto auto;
    width: 40px;
    height: 40px;
    border-radius: 20px;
    transition: background-color 0.15s;
}

.checkmark:hover {
    background-color: rgb(76, 74, 104);
    cursor: pointer;
}

.checkmark img {
    width: 60%;
    height: 60%;
}

.content {
    width: 80%;
    color: white;
    display: flex;
    flex-direction: column;
    padding: 50px;
    overflow-wrap: break-word;
}

.iframe-container {
    display: flex;
    justify-content: center;
    width: 100%;
    margin-bottom: 32px;
}

.course-page iframe {
    width: 100%;
    aspect-ratio: 16 / 9;
    border-radius: 10px;
}

@media (max-width: 763px) {
    .content {
        padding: 20px 0 0;
        width: 90%;
    }

    .checkmark {
        inset: 0px 0px auto auto;
    }

    .with-sidebar {
        padding: 50px calc(10vw);
    }

    .sidebar-toggle {
        inset: 20px 20px auto auto;
    }

    .left {
        inset: 0 0 0 auto;
        width: 250px;
        padding: 80px 20px 20px;
    }

    .left-show {
        transform: translateX(100%);
    }

    .left .home-button {
        inset: 20px auto auto 20px;
    }

    .blur-filter {
        position: fixed;
        inset: 0 0 0 0;
        z-index: 100;
        backdrop-filter: blur(4px);
        background-color: rgba(0, 0, 0, 0.238);
        transition: backdrop-filter 0.3s, background-color 0.3s;
        pointer-events: none;
    }

    .blur-filter-off {
        backdrop-filter: blur(0);
        background-color: rgba(0, 0, 0, 0);
    }
}