.chapter-hub {
    --chapter-ink: #123e39;
    --chapter-muted: #66817d;
    --chapter-teal: #087d6b;
    --chapter-teal-dark: #075e53;
    --chapter-mint: #edf8f5;
    --chapter-line: #dce9e6;
    --chapter-shadow: 0 18px 55px rgba(21, 75, 68, 0.10);
    --chapter-radius: 22px;

    margin: -12px -22px 0;
    color: var(--chapter-ink);
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
    line-height: 1.5;
}

.chapter-hub * {
    box-sizing: border-box;
}

.chapter-hub a {
    color: inherit;
    text-decoration: none;
}

.chapter-hub .chapter-shell {
    width: min(1180px, calc(100% - 40px));
    margin: auto;
}

.chapter-hub .chapter-preview-notice {
    margin: 0 0 12px;
    padding: 9px 13px;
    border: 1px solid #ead5a7;
    border-radius: 9px;
    background: #fff8e9;
    color: #79551b;
    font-size: 13px;
    font-weight: 800;
    text-align: center;
}

.chapter-hub .chapter-hero {
    position: relative;
    display: grid;
    grid-template-columns: 1.02fr 0.98fr;
    align-items: center;
    min-height: 420px;
    overflow: hidden;
    padding: 54px;
    border-radius: 30px;
    background: linear-gradient(125deg, #0d5e55 0%, #087e6c 56%, #10a083 100%);
    color: #ffffff;
    box-shadow: var(--chapter-shadow);
}

.chapter-hub .chapter-hero::before {
    position: absolute;
    top: -190px;
    right: -150px;
    width: 420px;
    height: 420px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 50%;
    content: "";
}

.chapter-hub .chapter-hero-copy {
    position: relative;
    z-index: 2;
}

.chapter-hub .chapter-hero-topline {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

.chapter-hub .chapter-eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.14);
    font-size: 13px;
    font-weight: 800;
}

.chapter-hub .chapter-hero h1 {
    max-width: 560px;
    margin: 18px 0 14px;
    color: #ffffff;
    font: 700 clamp(38px, 5vw, 64px) / 1.02 Georgia, serif;
    letter-spacing: -0.035em;
}

.chapter-hub .chapter-hero-copy > p {
    max-width: 540px;
    margin: 0 0 26px;
    color: #d8f3ed;
    font-size: 18px;
}

.chapter-hub .chapter-hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.chapter-hub .chapter-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 13px 18px;
    border: 0;
    border-radius: 12px;
    font-weight: 800;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.chapter-hub .chapter-btn:hover {
    transform: translateY(-2px);
}

.chapter-hub .chapter-btn-primary {
    background: #ffffff;
    color: var(--chapter-teal-dark);
    box-shadow: 0 10px 22px rgba(0, 0, 0, 0.12);
}

.chapter-hub .chapter-btn-ghost {
    border: 1px solid rgba(255, 255, 255, 0.32);
    background: rgba(255, 255, 255, 0.08);
    color: #ffffff;
}

.chapter-hub .chapter-btn-teal {
    background: #19a98e;
    color: #ffffff;
}

.chapter-hub .chapter-hero-stats {
    display: flex;
    gap: 22px;
    margin-top: 32px;
    color: #d8f3ed;
    font-size: 13px;
}

.chapter-hub .chapter-hero-stats span {
    min-width: 0;
}

.chapter-hub .chapter-hero-stats strong {
    display: block;
    color: #ffffff;
    font-size: 18px;
}

.chapter-hub .chapter-hero-board {
    position: relative;
    height: 300px;
    margin-left: 30px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: 24px;
    background: rgba(255, 255, 255, 0.1);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.12);
}

.chapter-hub .chapter-hero-media {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.chapter-hub video.chapter-hero-media {
    object-fit: cover;
}

.chapter-hub .chapter-hero-placeholder {
    display: flex;
    align-items: center;
    justify-content: space-evenly;
    width: 100%;
    height: 100%;
    color: #aaf3e4;
    font-size: 62px;
}

.chapter-hub .chapter-hero-placeholder span:nth-child(2) {
    color: #ffd36d;
    font-size: 95px;
}

.chapter-hub .chapter-overall-progress {
    width: 190px;
    padding: 10px 12px 11px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 13px;
    background: rgba(4, 63, 56, 0.72);
    box-shadow: 0 8px 22px rgba(3, 49, 44, 0.12),
        inset 0 1px 0 rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(10px);
}

.chapter-hub .chapter-progress-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    margin-bottom: 7px;
    color: #d8f3ed;
    font-size: 11px;
    font-weight: 750;
}

.chapter-hub .chapter-progress-meta strong {
    color: #ffffff;
    font-size: 12px;
}

.chapter-hub .chapter-progress-track {
    height: 5px;
    overflow: hidden;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.16);
}

.chapter-hub .chapter-progress-track span {
    display: block;
    height: 100%;
    border-radius: inherit;
    background: linear-gradient(90deg, #aaf3e4, #ffffff);
    box-shadow: 0 0 12px rgba(196, 255, 243, 0.38);
}

.chapter-hub .chapter-pathway {
    position: relative;
    z-index: 4;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    width: min(1010px, calc(100% - 28px));
    margin: -26px auto 0;
    overflow: hidden;
    border: 1px solid var(--chapter-line);
    border-radius: 18px;
    background: #ffffff;
    box-shadow: 0 14px 36px rgba(20, 70, 63, 0.11);
}

.chapter-hub .chapter-pathway a {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 22px 26px;
    transition: background 0.2s;
}

.chapter-hub .chapter-pathway a:hover {
    background: #f2faf8;
}

.chapter-hub .chapter-pathway a:not(:last-child) {
    border-right: 1px solid var(--chapter-line);
}

.chapter-hub .chapter-path-icon {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    flex: 0 0 auto;
    border-radius: 12px;
    background: var(--chapter-mint);
    color: var(--chapter-teal);
    font-size: 20px;
    font-weight: 900;
}

.chapter-hub .chapter-pathway strong,
.chapter-hub .chapter-pathway small {
    display: block;
}

.chapter-hub .chapter-pathway strong {
    font-size: 16px;
}

.chapter-hub .chapter-pathway small {
    color: var(--chapter-muted);
}

.chapter-hub .chapter-readiness {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    width: min(1010px, calc(100% - 28px));
    margin: 28px auto 0;
    padding: 18px 22px;
    border: 1px solid var(--chapter-line);
    border-radius: 16px;
    background: #f4fbf9;
}

.chapter-hub .chapter-readiness-title {
    display: flex;
    align-items: center;
    gap: 12px;
    white-space: nowrap;
}

.chapter-hub .chapter-readiness-icon {
    display: grid;
    place-items: center;
    width: 36px;
    height: 36px;
    flex: 0 0 auto;
    border-radius: 11px;
    background: #dff3ee;
    color: var(--chapter-teal);
    font-weight: 900;
}

.chapter-hub .chapter-readiness-title strong,
.chapter-hub .chapter-readiness-title small {
    display: block;
}

.chapter-hub .chapter-readiness-title strong {
    font-size: 15px;
}

.chapter-hub .chapter-readiness-title small {
    margin-top: 2px;
    color: var(--chapter-muted);
}

.chapter-hub .chapter-readiness-topics {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 8px;
}

.chapter-hub .chapter-readiness-topics span {
    padding: 7px 11px;
    border: 1px solid var(--chapter-line);
    border-radius: 999px;
    background: #ffffff;
    color: #47706a;
    font-size: 12px;
    font-weight: 800;
}

.chapter-hub .chapter-section {
    padding: 80px 0 0;
    scroll-margin-top: 88px;
}

.chapter-hub .chapter-section-head {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 24px;
    margin-bottom: 28px;
}

.chapter-hub .chapter-kicker {
    margin-bottom: 7px;
    color: var(--chapter-teal);
    font-size: 13px;
    font-weight: 900;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.chapter-hub .chapter-section-head h2,
.chapter-hub .chapter-practice-top h2 {
    margin: 0;
    font: 700 clamp(30px, 4vw, 44px) / 1.08 Georgia, serif;
    letter-spacing: -0.025em;
}

.chapter-hub .chapter-section-head > p {
    max-width: 420px;
    margin: 0;
    color: var(--chapter-muted);
}

.chapter-hub .chapter-concepts {
    display: grid;
    gap: 22px;
}

.chapter-hub .chapter-concept {
    display: grid;
    grid-template-columns: 42% 58%;
    min-height: 285px;
    overflow: hidden;
    border: 1px solid var(--chapter-line);
    border-radius: var(--chapter-radius);
    background: #ffffff;
    box-shadow: 0 10px 35px rgba(21, 74, 66, 0.07);
    transition: transform 0.25s, box-shadow 0.25s;
}

.chapter-hub .chapter-concept:hover {
    transform: translateY(-4px);
    box-shadow: var(--chapter-shadow);
}

.chapter-hub .chapter-concept:nth-child(even) {
    grid-template-columns: 58% 42%;
}

.chapter-hub .chapter-concept:nth-child(even) .chapter-concept-visual {
    order: 2;
}

.chapter-hub .chapter-concept:nth-child(even) .chapter-concept-copy {
    order: 1;
}

.chapter-hub .chapter-concept-visual {
    position: relative;
    display: grid;
    place-items: center;
    min-height: 285px;
    overflow: hidden;
}

.chapter-hub .chapter-concept-visual img,
.chapter-hub .chapter-concept-visual video {
    display: block;
    width: 84%;
    height: 84%;
    object-fit: contain;
}

.chapter-hub .chapter-tone-1 {
    background: linear-gradient(135deg, #edf1ff, #e4f7ff);
}

.chapter-hub .chapter-tone-2 {
    background: linear-gradient(135deg, #e5f7f3, #e6f2ff);
}

.chapter-hub .chapter-tone-3 {
    background: linear-gradient(135deg, #fff2dc, #ffe9d9);
}

.chapter-hub .chapter-tone-4 {
    background: linear-gradient(135deg, #f9e8f1, #e8f8f4);
}

.chapter-hub .chapter-concept-placeholder {
    color: #7158df;
    font-size: 86px;
    font-weight: 300;
}

.chapter-hub .chapter-concept-copy {
    display: flex;
    min-width: 0;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    padding: 38px 44px;
}

.chapter-hub .chapter-concept-number {
    color: #a5b8b4;
    font-size: 13px;
    font-weight: 900;
    letter-spacing: 0.12em;
}

.chapter-hub .chapter-concept h3 {
    max-width: 100%;
    margin: 9px 0 10px;
    font: 700 30px Georgia, serif;
    overflow-wrap: break-word;
}

.chapter-hub .chapter-concept-copy > p {
    width: 100%;
    max-width: 470px;
    margin: 0 0 20px;
    color: var(--chapter-muted);
    font-size: 16px;
}

.chapter-hub .chapter-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 14px;
}

.chapter-hub .chapter-pills span {
    padding: 6px 10px;
    border-radius: 999px;
    background: var(--chapter-mint);
    color: #47706a;
    font-size: 12px;
    font-weight: 800;
}

.chapter-hub .chapter-learning-steps {
    display: flex;
    align-items: center;
    gap: 7px;
    margin: 0 0 12px;
    color: #718985;
    font-size: 12px;
    font-weight: 850;
    letter-spacing: 0.01em;
    white-space: nowrap;
}

.chapter-hub .chapter-learning-steps span {
    display: flex;
    align-items: center;
    gap: 5px;
}

.chapter-hub .chapter-learning-steps span::before {
    width: 6px;
    height: 6px;
    border: 1.5px solid #65ad9f;
    border-radius: 50%;
    background: #f8fcfb;
    content: "";
}

.chapter-hub .chapter-learning-steps i {
    width: 15px;
    height: 1px;
    background: #c9deda;
}

.chapter-hub .chapter-text-link {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--chapter-teal);
    font-weight: 900;
}

.chapter-hub .chapter-empty {
    padding: 35px;
    border: 1px dashed var(--chapter-line);
    border-radius: 18px;
    color: var(--chapter-muted);
    text-align: center;
}

.chapter-hub .chapter-practice {
    position: relative;
    overflow: hidden;
    padding: 42px;
    border-radius: 28px;
    background: #102f2c;
    color: #ffffff;
}

.chapter-hub .chapter-practice::after {
    position: absolute;
    top: -100px;
    right: -110px;
    width: 280px;
    height: 280px;
    border-radius: 50%;
    background: #0d7e6c;
    opacity: 0.25;
    filter: blur(2px);
    content: "";
}

.chapter-hub .chapter-practice-top {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: 1fr auto;
    align-items: center;
    gap: 28px;
}

.chapter-hub .chapter-practice-top h2 {
    color: #ffffff;
}

.chapter-hub .chapter-practice-top p {
    max-width: 560px;
    margin: 10px 0 0;
    color: #bcd2ce;
}

.chapter-hub .chapter-question-progress {
    position: relative;
    display: grid;
    place-items: center;
    width: 122px;
    height: 122px;
    border-radius: 50%;
    background: conic-gradient(
        #34d6b5 var(--chapter-question-progress),
        rgba(255, 255, 255, 0.12) 0
    );
}

.chapter-hub .chapter-question-progress::after {
    position: absolute;
    inset: 10px;
    border-radius: 50%;
    background: #102f2c;
    content: "";
}

.chapter-hub .chapter-question-progress div {
    position: relative;
    z-index: 1;
    color: #a9c5c0;
    font-size: 12px;
    text-align: center;
}

.chapter-hub .chapter-question-progress strong {
    display: block;
    color: #ffffff;
    font-size: 25px;
}

.chapter-hub .chapter-question-progress.is-unavailable strong {
    font-size: 14px;
    line-height: 1.1;
}

.chapter-hub .chapter-questions {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 10px;
    margin-top: 32px;
}

.chapter-hub .chapter-question {
    padding: 14px 10px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.07);
    color: #e9f5f2;
    font-weight: 800;
    text-align: center;
    transition: transform 0.2s, background 0.2s, color 0.2s;
}

.chapter-hub .chapter-question:hover,
.chapter-hub .chapter-question.is-active {
    transform: translateY(-2px);
    background: #ffffff;
    color: var(--chapter-teal-dark);
}

.chapter-hub .chapter-question.is-done::before {
    color: #4be0c0;
    content: "✓ ";
}

.chapter-hub .chapter-practice-empty {
    position: relative;
    z-index: 2;
    margin: 28px 0 0;
    color: #bcd2ce;
}

.chapter-hub .chapter-practice-actions {
    position: relative;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    margin-top: 20px;
    color: #a9c5c0;
    font-size: 14px;
}

.chapter-hub .chapter-revision {
    display: grid;
    grid-template-columns: 1.15fr 0.85fr;
    gap: 22px;
}

.chapter-hub .chapter-revision-main {
    padding: 38px;
    border: 1px solid var(--chapter-line);
    border-radius: 24px;
    background: linear-gradient(125deg, #eaf7f4, #f8fcfb);
}

.chapter-hub .chapter-revision-main h3 {
    margin: 0 0 8px;
    font: 700 29px Georgia, serif;
}

.chapter-hub .chapter-revision-main > p {
    margin: 0 0 25px;
    color: var(--chapter-muted);
}

.chapter-hub .chapter-revision-links {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.chapter-hub .chapter-revision-links > a,
.chapter-hub .chapter-revision-links > span {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    padding: 18px;
    border: 1px solid var(--chapter-line);
    border-radius: 15px;
    background: #ffffff;
    font-weight: 850;
}

.chapter-hub .chapter-revision-links > a:hover {
    border-color: #8dcbbf;
}

.chapter-hub .chapter-revision-links .is-disabled {
    color: #879c98;
}

.chapter-hub .chapter-revision-links small {
    font-size: 10px;
    font-weight: 700;
}

.chapter-hub .chapter-video-card {
    position: relative;
    display: flex;
    min-height: 250px;
    flex-direction: column;
    justify-content: space-between;
    overflow: hidden;
    padding: 35px;
    border-radius: 24px;
    background: linear-gradient(145deg, #6c55d8, #4d3ca7);
    color: #ffffff;
}

.chapter-hub .chapter-video-card::after {
    position: absolute;
    top: -65px;
    right: -65px;
    width: 190px;
    height: 190px;
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: 50%;
    content: "";
}

.chapter-hub .chapter-video-card.is-disabled {
    opacity: 0.8;
    filter: saturate(0.55);
}

.chapter-hub .chapter-play {
    position: relative;
    z-index: 1;
    display: grid;
    place-items: center;
    width: 58px;
    height: 58px;
    border-radius: 50%;
    background: #ffffff;
    color: #5f49c4;
    font-size: 22px;
    box-shadow: 0 12px 24px rgba(35, 18, 100, 0.22);
}

.chapter-hub .chapter-video-card div {
    position: relative;
    z-index: 1;
}

.chapter-hub .chapter-video-card small {
    color: #ded8ff;
    font-size: 11px;
    font-weight: 900;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.chapter-hub .chapter-video-card h3 {
    margin: 5px 0;
    font: 700 28px Georgia, serif;
}

.chapter-hub .chapter-video-card p {
    margin: 0;
    color: #ded8ff;
}

.chapter-hub .chapter-help {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 28px;
    margin: 28px 0 0;
    padding: 24px 28px;
    border: 1px solid #cfe6e1;
    border-radius: 20px;
    background: linear-gradient(115deg, #f1faf8, #fbfefd);
    box-shadow: 0 10px 30px rgba(21, 74, 66, 0.05);
}

.chapter-hub .chapter-help-copy {
    display: flex;
    align-items: center;
    gap: 16px;
}

.chapter-hub .chapter-help-icon {
    display: grid;
    place-items: center;
    width: 46px;
    height: 46px;
    flex: 0 0 auto;
    border-radius: 14px;
    background: #dff3ee;
    color: var(--chapter-teal);
    font: 700 23px Georgia, serif;
}

.chapter-hub .chapter-help h3 {
    margin: 0 0 3px;
    font: 700 22px Georgia, serif;
}

.chapter-hub .chapter-help p {
    margin: 0;
    color: var(--chapter-muted);
    font-size: 14px;
}

.chapter-hub .chapter-help-button {
    flex: 0 0 auto;
    padding: 11px 16px;
    border-radius: 11px;
    background: var(--chapter-teal);
    color: #ffffff;
    font-size: 14px;
    font-weight: 850;
    box-shadow: 0 8px 18px rgba(8, 125, 107, 0.16);
    transition: transform 0.2s, box-shadow 0.2s;
}

.chapter-hub .chapter-help-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 11px 22px rgba(8, 125, 107, 0.22);
}

@media (max-width: 900px) {
    .chapter-hub .chapter-hero {
        grid-template-columns: 1fr;
        min-height: auto;
        padding: 42px;
    }

    .chapter-hub .chapter-hero-board {
        height: 260px;
        margin: 36px 0 0;
    }

    .chapter-hub .chapter-readiness {
        align-items: flex-start;
        flex-direction: column;
    }

    .chapter-hub .chapter-readiness-topics {
        justify-content: flex-start;
    }

    .chapter-hub .chapter-concepts {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .chapter-hub .chapter-concept,
    .chapter-hub .chapter-concept:nth-child(even) {
        grid-template-columns: 1fr;
        min-height: 0;
    }

    .chapter-hub .chapter-concept .chapter-concept-visual,
    .chapter-hub .chapter-concept:nth-child(even) .chapter-concept-visual {
        order: 1;
        min-height: 220px;
    }

    .chapter-hub .chapter-concept .chapter-concept-copy,
    .chapter-hub .chapter-concept:nth-child(even) .chapter-concept-copy {
        order: 2;
        padding: 28px;
    }

    .chapter-hub .chapter-revision {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 800px) {
    .chapter-hub {
        margin: 0 -16px;
    }
}

@media (max-width: 640px) {
    .chapter-hub .chapter-shell {
        width: min(100% - 24px, 1180px);
    }

    .chapter-hub .chapter-hero {
        padding: 29px 22px;
        border-radius: 22px;
    }

    .chapter-hub .chapter-hero h1 {
        max-width: 10ch;
        font-size: 42px;
        overflow-wrap: normal;
    }

    .chapter-hub .chapter-hero-copy > p {
        font-size: 16px;
    }

    .chapter-hub .chapter-hero-actions .chapter-btn {
        width: 100%;
    }

    .chapter-hub .chapter-hero-stats {
        display: grid;
        grid-template-columns: repeat(3, minmax(0, 1fr));
        gap: 8px;
        font-size: 11px;
    }

    .chapter-hub .chapter-hero-stats strong {
        font-size: 16px;
    }

    .chapter-hub .chapter-hero-board {
        height: 220px;
        margin-top: 28px;
    }

    .chapter-hub .chapter-pathway {
        grid-template-columns: 1fr;
        margin-top: -18px;
    }

    .chapter-hub .chapter-pathway a:not(:last-child) {
        border-right: 0;
        border-bottom: 1px solid var(--chapter-line);
    }

    .chapter-hub .chapter-readiness {
        width: 100%;
        margin-top: 20px;
        padding: 16px;
    }

    .chapter-hub .chapter-readiness-title {
        white-space: normal;
    }

    .chapter-hub .chapter-readiness-topics {
        display: grid;
        grid-template-columns: 1fr;
        width: 100%;
    }

    .chapter-hub .chapter-readiness-topics span {
        text-align: center;
    }

    .chapter-hub .chapter-section {
        padding-top: 62px;
    }

    .chapter-hub .chapter-section-head {
        align-items: flex-start;
        flex-direction: column;
    }

    .chapter-hub .chapter-section-head > p {
        font-size: 15px;
    }

    .chapter-hub .chapter-concepts {
        grid-template-columns: 1fr;
    }

    .chapter-hub .chapter-concept,
    .chapter-hub .chapter-concept:nth-child(even) {
        grid-template-columns: 1fr;
    }

    .chapter-hub .chapter-concept:nth-child(even) .chapter-concept-visual {
        order: 1;
    }

    .chapter-hub .chapter-concept:nth-child(even) .chapter-concept-copy {
        order: 2;
    }

    .chapter-hub .chapter-concept-visual {
        min-height: 210px;
    }

    .chapter-hub .chapter-concept-copy {
        padding: 28px 25px;
    }

    .chapter-hub .chapter-concept h3 {
        font-size: 26px;
    }

    .chapter-hub .chapter-practice {
        padding: 29px 20px;
    }

    .chapter-hub .chapter-practice-top {
        grid-template-columns: 1fr;
    }

    .chapter-hub .chapter-question-progress {
        display: block;
        width: 100%;
        height: 12px;
        border-radius: 999px;
        background: linear-gradient(
            90deg,
            #34d6b5 var(--chapter-question-progress),
            rgba(255, 255, 255, 0.12) 0
        );
    }

    .chapter-hub .chapter-question-progress::after,
    .chapter-hub .chapter-question-progress div {
        display: none;
    }

    .chapter-hub .chapter-question-progress.is-unavailable {
        display: grid;
        width: 100%;
        height: 44px;
        border: 1px solid rgba(255, 255, 255, 0.14);
        background: rgba(255, 255, 255, 0.08);
    }

    .chapter-hub .chapter-question-progress.is-unavailable::after {
        display: none;
    }

    .chapter-hub .chapter-question-progress.is-unavailable div {
        display: block;
    }

    .chapter-hub .chapter-questions {
        grid-template-columns: repeat(2, 1fr);
    }

    .chapter-hub .chapter-practice-actions {
        align-items: stretch;
        flex-direction: column;
    }

    .chapter-hub .chapter-practice-actions .chapter-btn {
        width: 100%;
    }

    .chapter-hub .chapter-revision-links {
        grid-template-columns: 1fr;
    }

    .chapter-hub .chapter-help {
        align-items: stretch;
        flex-direction: column;
        gap: 18px;
        padding: 20px;
    }

    .chapter-hub .chapter-help-copy {
        align-items: flex-start;
    }

    .chapter-hub .chapter-help-button {
        text-align: center;
    }
}

@media (prefers-reduced-motion: reduce) {
    .chapter-hub * {
        scroll-behavior: auto !important;
        transition: none !important;
    }
}