/* Videos share the site's paper palette and editorial typography. */
#page-ai-math [hidden] {
    display: none !important;
}

#page-ai-math .ai-math-tabs {
    --tab-gap: 0.375rem;
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--tab-gap);
    isolation: isolate;
    width: 100%;
    margin: 0 0 1.65rem;
    padding: 0.375rem;
    border: 1px solid var(--border-color);
    border-radius: 9px;
    background: var(--surface-wash);
}

/* One shared background slides between the two equal-width tabs. */
#page-ai-math .ai-math-tabs::before {
    content: "";
    grid-area: 1 / 1;
    border-radius: 5px;
    background: var(--link-color);
    pointer-events: none;
    transition: transform 0.48s cubic-bezier(0.4, 0, 0.2, 1);
}

#page-ai-math .ai-math-tabs[data-view="videos"]::before {
    transform: translateX(calc(100% + var(--tab-gap)));
}

#page-ai-math .ai-math-tab {
    position: relative;
    z-index: 1;
    grid-row: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 0;
    min-height: 56px;
    padding: 0.75rem 1rem;
    border: 1px solid transparent;
    border-radius: 5px;
    background: transparent;
    color: var(--secondary-text);
    font-family: var(--font-reading);
    font-size: 1.08rem;
    font-weight: 500;
    line-height: 1.4;
    text-align: center;
    cursor: pointer;
    transition: color 0.24s ease 0.12s;
}

#page-ai-math .ai-math-tab:first-of-type {
    grid-column: 1;
}

#page-ai-math .ai-math-tab:last-of-type {
    grid-column: 2;
}

#page-ai-math .ai-math-tab > span {
    min-width: 0;
}

#page-ai-math .ai-math-tab:hover {
    color: var(--link-hover);
}

#page-ai-math .ai-math-tab[aria-selected="true"] {
    color: var(--bg-color);
}

#page-ai-math :is(.ai-math-tab, .ai-math-video-play, .ai-math-video h3 a, .ai-math-video-links a):focus-visible,
#page-ai-math [role="tabpanel"]:focus-visible {
    outline: 2px solid var(--link-color);
    outline-offset: 4px;
}

#page-ai-math [role="tabpanel"][hidden] {
    display: none !important;
}

#page-ai-math .ai-math-video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 19rem), 1fr));
    gap: 2rem 2rem;
    align-items: stretch;
}

#page-ai-math .ai-math-video-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem 1.25rem;
    margin: -0.25rem 0 0.5rem;
}

#page-ai-math .ai-math-video-filters button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    min-height: 44px;
    padding: 0.45rem 0;
    border: 0;
    border-bottom: 2px solid transparent;
    background: transparent;
    color: var(--secondary-text);
    font: inherit;
    font-size: 0.93rem;
    cursor: pointer;
}

#page-ai-math .ai-math-video-filters button[aria-pressed="true"] {
    border-bottom-color: currentColor;
    color: var(--link-color);
    font-weight: 500;
}

#page-ai-math .ai-math-video-filters button:hover {
    color: var(--link-hover);
}

#page-ai-math .ai-math-video-filters button:focus-visible {
    outline: 2px solid var(--link-color);
    outline-offset: 4px;
}

#page-ai-math .ai-math-video-filter-count {
    font-family: var(--font-detail);
    font-size: 0.72rem;
    font-variant-numeric: tabular-nums;
}

#page-ai-math .ai-math-video {
    display: flex;
    flex-direction: column;
    min-width: 0;
    padding-top: 1.25rem;
    border-top: 1px solid var(--section-rule);
}

#page-ai-math .ai-math-video-media {
    flex: 0 0 auto;
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 9;
    margin: 0 0 1.1rem;
    border-radius: 3px;
    background: var(--tag-bg);
}

#page-ai-math .ai-math-video-play {
    position: absolute;
    inset: 0;
    display: block;
    width: 100%;
    height: 100%;
    min-height: 44px;
    padding: 0;
    border: 0;
    border-radius: inherit;
    background: #211b17;
    color: #fff;
    cursor: pointer;
    isolation: isolate;
}

#page-ai-math .ai-math-video-play img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: inherit;
}

#page-ai-math .ai-math-video-play::after {
    content: "";
    position: absolute;
    inset: 0;
    z-index: 1;
    border-radius: inherit;
    background: linear-gradient(transparent 45%, rgba(0, 0, 0, 0.58));
    pointer-events: none;
}

#page-ai-math .ai-math-video-play-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    z-index: 2;
    display: grid;
    place-items: center;
    width: 62px;
    height: 62px;
    border: 1px solid rgba(255, 255, 255, 0.65);
    border-radius: 50%;
    background: rgba(28, 22, 18, 0.88);
    color: #fff;
    transform: translate(-50%, -50%);
    transition: background-color 0.16s ease;
}

#page-ai-math .ai-math-video-play-icon svg {
    width: 25px;
    height: 25px;
    margin-left: 3px;
}

#page-ai-math .ai-math-video-play:hover .ai-math-video-play-icon,
#page-ai-math .ai-math-video-play:focus-visible .ai-math-video-play-icon {
    background: #875038;
}

#page-ai-math .ai-math-video-media iframe {
    position: absolute;
    inset: 0;
    display: block;
    width: 100%;
    height: 100%;
    border: 0;
    border-radius: inherit;
}

#page-ai-math .ai-math-video-body {
    flex: 1;
    min-width: 0;
}

/* Shared rows align the controls even when a neighbouring description opens. */
@supports (grid-template-rows: subgrid) {
    #page-ai-math .ai-math-video {
        display: grid;
        grid-row: span 3;
        grid-template-rows: subgrid;
        row-gap: 0;
    }
}

#page-ai-math .ai-math-video-meta {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 0.15rem 0.8rem;
    margin: 0 0 0.5rem;
    color: var(--secondary-text);
    font-family: var(--font-detail);
    font-size: 0.76rem;
    font-weight: 400;
    line-height: 1.65;
    font-variant-numeric: tabular-nums;
    overflow-wrap: anywhere;
}

#page-ai-math .ai-math-video h3 {
    margin: 0 0 0.55rem;
    font-family: var(--font-heading);
    font-size: 1.4rem;
    font-weight: 500;
    line-height: 1.35;
    letter-spacing: -0.018em;
    overflow-wrap: anywhere;
}

#page-ai-math .ai-math-video h3 a {
    display: inline-block;
    min-height: 44px;
    color: var(--text-color);
    text-decoration: none;
}

#page-ai-math .ai-math-video h3 a:hover {
    color: var(--link-color);
    text-decoration: none;
}

#page-ai-math .ai-math-video-speaker {
    margin: 0 0 1rem;
    color: var(--secondary-text);
    font-size: 0.96rem;
    line-height: 1.6;
}

#page-ai-math .ai-math-video-disclosure {
    min-width: 0;
}

#page-ai-math .ai-math-video-description-toggle {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    min-height: 44px;
    margin: 0;
    padding: 0.65rem 2.5rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--surface-wash);
    color: var(--secondary-text);
    font-family: var(--font-reading);
    font-size: 0.85rem;
    font-weight: 500;
    line-height: 1.4;
    text-align: center;
    cursor: pointer;
    transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

#page-ai-math .ai-math-video-description-toggle:hover,
#page-ai-math .ai-math-video-description-toggle[aria-expanded="true"] {
    background: var(--surface-wash-strong);
    border-color: rgba(var(--accent-rgb), 0.48);
    color: var(--link-color);
}

#page-ai-math .ai-math-video-description-toggle > span:first-child {
    min-width: 0;
    overflow-wrap: anywhere;
}

#page-ai-math .ai-math-video-description-toggle:focus-visible {
    border-color: var(--link-color);
    outline: 2px solid var(--link-color);
    outline-offset: 3px;
}

#page-ai-math .ai-math-video-description-chevron {
    position: absolute;
    right: 1rem;
    display: flex;
    align-items: center;
}

#page-ai-math .ai-math-video-description-toggle[aria-expanded="true"] .ai-math-video-description-chevron {
    transform: rotate(180deg);
}

#page-ai-math .ai-math-video-details {
    margin-top: 0.75rem;
    padding: 0.9rem 1rem 0.55rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--surface-wash);
}

#page-ai-math .ai-math-video-description {
    margin: 0;
    padding: 0;
    border: 0;
    color: var(--text-color);
    font-style: normal;
}

#page-ai-math .ai-math-video-description p {
    margin: 0;
    font-size: 0.99rem;
    line-height: 1.65;
    overflow-wrap: anywhere;
}

#page-ai-math .ai-math-video-links {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0 1.25rem;
    margin-top: 0.55rem;
}

#page-ai-math .ai-math-video-links a {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
    max-width: 100%;
    color: var(--link-color);
    font-size: 0.88rem;
    line-height: 1.5;
    text-decoration: none;
    text-underline-offset: 0.18em;
    overflow-wrap: anywhere;
}

#page-ai-math .ai-math-video-links a:hover {
    color: var(--link-hover);
    text-decoration: underline;
}

@media (max-width: 480px) {
    #page-ai-math .ai-math-tabs {
        --tab-gap: 0.25rem;
        padding: 0.25rem;
        margin-bottom: 1.35rem;
    }

    #page-ai-math .ai-math-tab {
        min-height: 64px;
        padding: 0.65rem 0.4rem;
        font-size: 0.96rem;
    }

    #page-ai-math .ai-math-video-grid {
        gap: 1.35rem;
    }

    #page-ai-math .ai-math-video h3 {
        font-size: 1.3rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    #page-ai-math .ai-math-tabs::before,
    #page-ai-math .ai-math-tab,
    #page-ai-math .ai-math-video-description-toggle,
    #page-ai-math .ai-math-video-play-icon {
        transition: none;
    }
}

@media (forced-colors: active) {
    #page-ai-math .ai-math-tabs::before {
        background: Highlight;
        forced-color-adjust: none;
    }

    #page-ai-math .ai-math-tabs,
    #page-ai-math .ai-math-tab {
        border-color: ButtonText;
    }

    #page-ai-math .ai-math-video-description-toggle {
        border-color: ButtonText;
    }

    #page-ai-math .ai-math-tab[aria-selected="true"] {
        color: HighlightText;
        border-color: Highlight;
        outline: 2px solid Highlight;
        outline-offset: -4px;
    }

    #page-ai-math .ai-math-video-play-icon {
        forced-color-adjust: none;
        background: #000;
        color: #fff;
    }
}

@media print {
    #page-ai-math .ai-math-tabs,
    #page-ai-math .ai-math-video-filters,
    #page-ai-math .ai-math-video-description-toggle,
    #page-ai-math .ai-math-video-media {
        display: none;
    }

    #page-ai-math .ai-math-video-grid {
        display: block;
    }

    #page-ai-math .ai-math-video {
        display: block;
        break-inside: avoid;
        padding-block: 1rem;
    }

    #page-ai-math .ai-math-video-details[hidden] {
        display: block !important;
    }

    #page-ai-math .ai-math-video-links a {
        min-height: 0;
    }
}