.presentation-page {
    min-height: 100vh;
    background:
        radial-gradient(circle at 18% 12%, rgba(183, 45, 83, 0.12), transparent 32rem),
        #f5f1e9;
    color: #15242a;
}

.presentation-page-shell {
    width: min(1180px, calc(100% - 32px));
    margin: 0 auto;
    padding: calc(112px + env(safe-area-inset-top, 0px)) 0 80px;
}

.presentation-list-shell {
    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;
    padding: 118px 0 80px;
}
.presentation-list-header {
    max-width: 820px;
    margin-bottom: 38px;
}
.presentation-list-header h1 {
    margin: 4px 0 12px;
    color: #17252b;
    font-size: clamp(44px, 7vw, 82px);
    line-height: 1;
}
.presentation-list-header > p:last-child {
    color: #637078;
    font-size: 17px;
    line-height: 1.8;
}
.presentation-search-form {
    max-width: 820px;
    margin-bottom: 28px;
}
.presentation-list-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(100%, 360px), 1fr));
    gap: 28px;
}
.presentation-list-card {
    overflow: hidden;
    color: #17252b;
    text-decoration: none;
    border: 1px solid rgba(16,47,53,.1);
    border-radius: 26px;
    background: #fff;
    box-shadow: 0 18px 44px rgba(26,44,50,.1);
    transition: transform 180ms ease, box-shadow 180ms ease;
}
.presentation-list-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 24px 54px rgba(26,44,50,.16);
}
.presentation-list-card img {
    width: 100%;
    aspect-ratio: 16 / 9;
    display: block;
    object-fit: cover;
    background: #102f35;
}
.presentation-list-card > div { padding: 24px; }
.presentation-list-card span {
    color: #c8395b;
    font-size: 12px;
    font-weight: 850;
    letter-spacing: .1em;
    text-transform: uppercase;
}
.presentation-list-card h2 {
    margin: 8px 0 10px;
    font-size: clamp(23px, 3vw, 32px);
    line-height: 1.25;
}
.presentation-list-card p {
    margin: 0 0 18px;
    color: #65727a;
    line-height: 1.7;
}
.presentation-list-card time {
    color: #899399;
    font-size: 13px;
}
.presentation-list-empty {
    grid-column: 1 / -1;
    padding: 56px 32px;
    text-align: center;
    border-radius: 26px;
    background: #fff;
}
.presentation-list-empty h2 { margin: 0 0 8px; }
.presentation-pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 18px;
    margin-top: 30px;
}
.presentation-pagination a {
    color: #b72d53;
    font-weight: 800;
}

.presentation-header {
    display: flex;
    gap: 24px;
    align-items: flex-end;
    justify-content: space-between;
    margin-bottom: 28px;
}

.presentation-header-copy {
    min-width: 0;
    max-width: 900px;
}

.presentation-header h1 {
    margin: 6px 0 12px;
    font-size: clamp(2rem, 5vw, 4rem);
    line-height: 1.12;
    letter-spacing: -0.035em;
}

.presentation-header-copy > p:last-child {
    max-width: 760px;
    color: #52636a;
    font-size: 1.05rem;
    line-height: 1.8;
}

.presentation-share {
    flex: 0 0 auto;
    display: grid;
    gap: 6px;
    justify-items: end;
    padding-bottom: 4px;
}

.presentation-share-button {
    display: inline-flex;
    gap: 8px;
    align-items: center;
    justify-content: center;
    min-height: 44px;
    padding: 10px 18px;
    border: 1px solid rgba(16, 47, 53, 0.18);
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.86);
    color: #102f35;
    font: inherit;
    font-weight: 800;
    cursor: pointer;
    box-shadow: 0 8px 22px rgba(16, 47, 53, 0.08);
    transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.presentation-share-button:hover {
    border-color: rgba(16, 47, 53, 0.36);
    background: #fff;
    transform: translateY(-1px);
}

.presentation-share-button:focus-visible {
    outline: 3px solid rgba(200, 57, 91, 0.3);
    outline-offset: 3px;
}

.presentation-share-button:disabled {
    cursor: wait;
    opacity: 0.65;
}

.presentation-share-status {
    min-height: 1.2em;
    color: #52636a;
    font-size: 0.78rem;
    font-weight: 700;
}

.presentation-stage {
    padding: clamp(12px, 2vw, 22px);
    border-radius: 24px;
    background: #102f35;
    box-shadow: 0 28px 70px rgba(16, 47, 53, 0.2);
}

.presentation-viewport {
    display: contents;
}

.presentation-screen {
    position: relative;
    overflow: hidden;
    aspect-ratio: 16 / 9;
    border-radius: 14px;
    background: #e9e4da;
}

.presentation-screen img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.presentation-start {
    position: absolute;
    inset: 50% auto auto 50%;
    display: inline-flex;
    gap: 10px;
    align-items: center;
    padding: 16px 24px;
    border: 0;
    border-radius: 999px;
    background: rgba(16, 47, 53, 0.94);
    color: #fff;
    font: inherit;
    font-weight: 800;
    cursor: pointer;
    transform: translate(-50%, -50%);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.3);
}

.presentation-start[hidden] {
    display: none;
}

.presentation-controls {
    display: grid;
    grid-template-columns: auto auto auto 1fr auto auto;
    gap: 10px;
    align-items: center;
    padding: 16px 2px 6px;
    color: #fff;
}

.presentation-controls button {
    display: grid;
    width: 44px;
    height: 44px;
    place-items: center;
    border: 1px solid rgba(255, 255, 255, 0.24);
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.08);
    color: #fff;
    font: inherit;
    font-size: 1.4rem;
    cursor: pointer;
}

.presentation-controls button:disabled {
    cursor: default;
    opacity: 0.35;
}

.presentation-controls .presentation-play {
    background: #b72d53;
    border-color: #b72d53;
}

.presentation-controls .presentation-fullscreen {
    font-size: 1.15rem;
}

.presentation-fullscreen-open {
    overflow: hidden;
}

.presentation-position {
    padding-left: 8px;
    font-variant-numeric: tabular-nums;
    font-weight: 750;
}

.presentation-speed {
    display: inline-flex;
    gap: 8px;
    align-items: center;
    font-size: 0.84rem;
}

.presentation-speed select {
    padding: 7px 9px;
    border: 1px solid rgba(255, 255, 255, 0.25);
    border-radius: 8px;
    background: #173e45;
    color: #fff;
}

.presentation-progress {
    display: block;
    padding: 4px 2px 2px;
}

.presentation-progress .visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.presentation-progress input {
    width: 100%;
    accent-color: #d84f72;
}

.presentation-stage:fullscreen,
.presentation-stage:-webkit-full-screen,
.presentation-stage.is-fullscreen {
    width: 100vw;
    height: 100vh;
    display: grid;
    place-items: center;
    padding: clamp(8px, 2vw, 22px);
    border-radius: 0;
    background: #102f35;
}

.presentation-stage.is-fullscreen {
    position: fixed;
    inset: 0;
    z-index: 1000;
}

.presentation-stage:fullscreen .presentation-viewport,
.presentation-stage:-webkit-full-screen .presentation-viewport,
.presentation-stage.is-fullscreen .presentation-viewport {
    position: relative;
    display: block;
    width: min(100%, calc((100vh - 16px) * 16 / 9));
    max-height: 100%;
    overflow: hidden;
    border-radius: 14px;
    aspect-ratio: 16 / 9;
    background: #e9e4da;
}

.presentation-stage:fullscreen .presentation-screen,
.presentation-stage:-webkit-full-screen .presentation-screen,
.presentation-stage.is-fullscreen .presentation-screen {
    width: 100%;
    height: 100%;
    border-radius: inherit;
}

.presentation-stage:fullscreen .presentation-overlay,
.presentation-stage:-webkit-full-screen .presentation-overlay,
.presentation-stage.is-fullscreen .presentation-overlay {
    position: absolute;
    inset: auto 0 0;
    z-index: 3;
    padding: 58px 12px 10px;
    background: linear-gradient(transparent, rgba(8, 31, 36, 0.92));
    opacity: 1;
    transform: translateY(0);
    transition: opacity 180ms ease, transform 180ms ease;
}

.presentation-stage:fullscreen .presentation-controls,
.presentation-stage:-webkit-full-screen .presentation-controls,
.presentation-stage.is-fullscreen .presentation-controls {
    grid-template-columns: auto auto auto 1fr auto auto;
    gap: 6px;
    padding: 3px 0 2px;
}

.presentation-stage:fullscreen .presentation-controls button,
.presentation-stage:-webkit-full-screen .presentation-controls button,
.presentation-stage.is-fullscreen .presentation-controls button {
    width: 38px;
    height: 38px;
    font-size: 1rem;
}

.presentation-stage:fullscreen .presentation-position,
.presentation-stage:-webkit-full-screen .presentation-position,
.presentation-stage.is-fullscreen .presentation-position {
    padding-left: 2px;
    font-size: 0.82rem;
}

.presentation-stage:fullscreen .presentation-speed,
.presentation-stage:-webkit-full-screen .presentation-speed,
.presentation-stage.is-fullscreen .presentation-speed {
    grid-column: auto;
    gap: 5px;
    font-size: 0.72rem;
}

.presentation-stage:fullscreen .presentation-speed select,
.presentation-stage:-webkit-full-screen .presentation-speed select,
.presentation-stage.is-fullscreen .presentation-speed select {
    padding: 5px 6px;
}

.presentation-stage:fullscreen .presentation-fullscreen,
.presentation-stage:-webkit-full-screen .presentation-fullscreen,
.presentation-stage.is-fullscreen .presentation-fullscreen {
    grid-column: auto;
    grid-row: auto;
}

.presentation-stage.is-fullscreen.is-controls-hidden {
    cursor: none;
}

.presentation-stage.is-fullscreen.is-controls-hidden .presentation-overlay {
    pointer-events: none;
    opacity: 0;
    transform: translateY(10px);
}

.presentation-thumbnails {
    display: grid;
    grid-auto-columns: minmax(132px, 180px);
    grid-auto-flow: column;
    gap: 12px;
    overflow-x: auto;
    margin: 22px 0;
    padding: 4px 2px 12px;
    scrollbar-width: thin;
}

.presentation-thumbnails button {
    position: relative;
    overflow: hidden;
    padding: 0;
    border: 3px solid transparent;
    border-radius: 10px;
    background: #fff;
    cursor: pointer;
    box-shadow: 0 5px 18px rgba(15, 23, 42, 0.1);
}

.presentation-thumbnails button.is-current {
    border-color: #b72d53;
}

.presentation-thumbnails img {
    display: block;
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
}

.presentation-thumbnails span {
    position: absolute;
    right: 6px;
    bottom: 6px;
    display: grid;
    min-width: 24px;
    height: 24px;
    padding: 0 5px;
    place-items: center;
    border-radius: 999px;
    background: rgba(16, 47, 53, 0.9);
    color: #fff;
    font-size: 0.75rem;
    font-weight: 800;
}

.presentation-related-books {
    margin-top: 34px;
    padding: clamp(22px, 4vw, 38px);
    border: 1px solid rgba(16, 47, 53, 0.1);
    border-radius: 24px;
    background: rgba(255, 255, 255, 0.78);
    box-shadow: 0 18px 48px rgba(16, 47, 53, 0.08);
}

.presentation-related-books-header {
    margin-bottom: 20px;
}

.presentation-related-books-header h2 {
    margin: 4px 0 6px;
    font-size: clamp(1.45rem, 3vw, 2rem);
    letter-spacing: -0.03em;
}

.presentation-related-books-header > p:last-child {
    margin: 0;
    color: #65727a;
}

.presentation-related-books-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
}

.presentation-related-book {
    display: grid;
    grid-template-columns: 74px minmax(0, 1fr);
    gap: 15px;
    align-items: center;
    min-width: 0;
    padding: 12px;
    border: 1px solid rgba(16, 47, 53, 0.1);
    border-radius: 18px;
    background: #fff;
    color: #17252b;
    text-decoration: none;
    transition: transform 180ms ease, box-shadow 180ms ease;
}

.presentation-related-book:hover {
    transform: translateY(-2px);
    box-shadow: 0 14px 32px rgba(16, 47, 53, 0.11);
}

.presentation-related-book img {
    width: 74px;
    height: 104px;
    display: block;
    border-radius: 10px;
    background: #f5f1e9;
    object-fit: cover;
}

.presentation-related-book span,
.presentation-related-book strong,
.presentation-related-book small {
    display: block;
    min-width: 0;
}

.presentation-related-book strong {
    font-size: 0.95rem;
    line-height: 1.45;
}

.presentation-related-book small {
    margin-top: 4px;
    color: #65727a;
}

.presentation-transcript {
    padding: clamp(18px, 4vw, 34px);
    border: 1px solid rgba(16, 47, 53, 0.12);
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.8);
}

.presentation-transcript summary {
    cursor: pointer;
    font-size: 1.05rem;
    font-weight: 850;
}

.presentation-transcript p {
    margin: 20px 0 0;
    white-space: pre-wrap;
    font-size: 1rem;
    line-height: 1.95;
}

@media (max-width: 1050px) {
    .presentation-related-books-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 680px) {
    .presentation-list-shell {
        width: min(100% - 24px, 560px);
        padding: 92px 0 58px;
    }

    .presentation-list-header { margin-bottom: 24px; }

    .presentation-list-header h1 { font-size: 48px; }

    .presentation-list-grid { gap: 18px; }

    .presentation-list-card { border-radius: 20px; }

    .presentation-list-card > div { padding: 20px; }

    .presentation-search-form { margin-bottom: 18px; }

    .presentation-page-shell {
        width: min(100% - 20px, 1180px);
        padding: calc(88px + env(safe-area-inset-top, 0px)) 0 58px;
    }

    .presentation-header {
        display: grid;
        gap: 14px;
        align-items: start;
    }

    .presentation-share {
        justify-items: start;
        padding-bottom: 0;
    }

    .presentation-stage {
        padding: 8px;
        border-radius: 16px;
    }

    .presentation-screen {
        border-radius: 10px;
    }

    .presentation-controls {
        grid-template-columns: auto auto auto 1fr auto;
    }

    .presentation-speed {
        grid-column: 1 / -1;
        justify-self: end;
    }

    .presentation-fullscreen {
        grid-column: 5;
        grid-row: 1;
    }

    .presentation-start {
        padding: 12px 18px;
    }

    .presentation-related-books {
        margin-top: 24px;
        padding: 20px 16px;
        border-radius: 18px;
    }

    .presentation-related-books-grid {
        grid-template-columns: 1fr;
    }
}

@media (orientation: landscape) and (max-height: 600px) {
    .presentation-stage:fullscreen,
    .presentation-stage:-webkit-full-screen,
    .presentation-stage.is-fullscreen {
        padding:
            max(5px, env(safe-area-inset-top))
            max(8px, env(safe-area-inset-right))
            max(5px, env(safe-area-inset-bottom))
            max(8px, env(safe-area-inset-left));
    }

    .presentation-stage:fullscreen .presentation-viewport,
    .presentation-stage:-webkit-full-screen .presentation-viewport,
    .presentation-stage.is-fullscreen .presentation-viewport {
        width: min(100%, calc((100vh - 10px) * 16 / 9));
        border-radius: 8px;
    }

    .presentation-stage:fullscreen .presentation-controls,
    .presentation-stage:-webkit-full-screen .presentation-controls,
    .presentation-stage.is-fullscreen .presentation-controls {
        grid-template-columns: auto auto auto 1fr auto auto;
        gap: 6px;
        padding: 2px 0 1px;
    }

    .presentation-stage:fullscreen .presentation-controls button,
    .presentation-stage:-webkit-full-screen .presentation-controls button,
    .presentation-stage.is-fullscreen .presentation-controls button {
        width: 36px;
        height: 36px;
        font-size: 1rem;
    }

    .presentation-stage:fullscreen .presentation-position,
    .presentation-stage:-webkit-full-screen .presentation-position,
    .presentation-stage.is-fullscreen .presentation-position {
        padding-left: 2px;
        font-size: 0.82rem;
    }

    .presentation-stage:fullscreen .presentation-speed,
    .presentation-stage:-webkit-full-screen .presentation-speed,
    .presentation-stage.is-fullscreen .presentation-speed {
        grid-column: auto;
        gap: 5px;
        font-size: 0.72rem;
    }

    .presentation-stage:fullscreen .presentation-speed select,
    .presentation-stage:-webkit-full-screen .presentation-speed select,
    .presentation-stage.is-fullscreen .presentation-speed select {
        padding: 5px 6px;
    }

    .presentation-stage:fullscreen .presentation-fullscreen,
    .presentation-stage:-webkit-full-screen .presentation-fullscreen,
    .presentation-stage.is-fullscreen .presentation-fullscreen {
        grid-column: auto;
        grid-row: auto;
    }

    .presentation-stage:fullscreen .presentation-progress,
    .presentation-stage:-webkit-full-screen .presentation-progress,
    .presentation-stage.is-fullscreen .presentation-progress {
        padding: 0;
        line-height: 1;
    }

    .presentation-stage:fullscreen .presentation-overlay,
    .presentation-stage:-webkit-full-screen .presentation-overlay,
    .presentation-stage.is-fullscreen .presentation-overlay {
        padding: 42px 8px 6px;
    }
}