/* Collection entry and single-video introduction overlay. */
.section-heading.has-intro-action {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}
.intro-trigger {
    display: inline-flex;
    align-items: center;
    flex: 0 0 auto;
    transform: translateY(3px);
    gap: 7px;
    min-height: 34px;
    padding: 0 12px;
    border: 1px solid color-mix(in srgb, var(--color-accent-purple) 74%, transparent);
    border-radius: 6px;
    background: color-mix(in srgb, var(--color-accent-purple) 38%, var(--color-surface-dark));
    box-shadow: 0 5px 14px rgba(0, 0, 0, .14);
    color: color-mix(in srgb, var(--color-text-light) 88%, transparent);
    font: inherit;
    font-size: 12px;
    font-weight: 650;
    white-space: nowrap;
    cursor: default;
}
.intro-trigger:enabled { cursor: pointer; }
.intro-trigger:enabled:hover { border-color: var(--color-accent-purple); background: color-mix(in srgb, var(--color-accent-purple) 52%, var(--color-surface-dark)); color: var(--color-text-light); }
.intro-trigger:focus-visible { outline: 2px solid color-mix(in srgb, var(--color-accent-purple) 70%, transparent); outline-offset: 3px; border-radius: 6px; }

/* The dialog remains a transparent technical shell around the video. */
.about-dialog {
    position: fixed;
    inset: 0;
    width: fit-content;
    height: fit-content;
    max-width: calc(100vw - 20px);
    max-height: calc(100vh - 20px);
    max-height: calc(100dvh - 20px);
    margin: auto;
    padding: 0;
    border: 0;
    border-radius: 0;
    background: transparent;
    box-shadow: none;
    overflow: visible;
}
.about-dialog::backdrop {
    background: color-mix(in srgb, var(--color-surface-dark) 52%, transparent);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
}
.about-dialog .overlay-close {
    top: 0;
    right: 0;
    z-index: 5;
    border: 1px solid color-mix(in srgb, var(--color-text-light) 22%, transparent);
    border-radius: 50%;
    background: color-mix(in srgb, var(--color-surface-dark) 72%, transparent);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    box-shadow: 0 6px 18px rgba(0, 0, 0, .34);
    color: var(--color-text-light);
}
.about-dialog .overlay-close:hover { background: color-mix(in srgb, var(--color-accent-purple) 52%, transparent); }
.about-content {
    position: relative;
    display: grid;
    justify-items: center;
    padding: 22px 22px 0 0;
}
.about-stage {
    position: relative;
    width: min(420px, calc((100dvh - 112px) * 9 / 16), calc(100vw - 42px));
    overflow: hidden;
    border: 1px solid color-mix(in srgb, var(--color-accent-purple) 46%, var(--color-text-light));
    border-radius: 8px;
    background: var(--color-surface-dark);
    box-shadow: 0 18px 48px rgba(0, 0, 0, .45);
    line-height: 0;
}
.about-video {
    display: block;
    width: 100%;
    height: auto;
    border: 0;
    border-radius: 0;
    object-fit: contain;
}
.about-video-toggle {
    position: absolute;
    inset: 0;
    z-index: 2;
    display: grid;
    place-items: center;
    width: 52px;
    height: 52px;
    margin: auto;
    padding: 0;
    border: 0;
    background: transparent;
    color: var(--color-text-light);
    cursor: pointer;
}
.about-video-toggle svg {
    grid-area: 1 / 1;
    filter: drop-shadow(0 1px 1px rgba(0, 0, 0, 1)) drop-shadow(0 2px 3px rgba(0, 0, 0, .78));
}
.guide-icon-pause { display: none; }
.about-video-toggle.is-playing .guide-icon-play { display: none; }
.about-video-toggle.is-playing .guide-icon-pause { display: block; }
.about-video-toggle:focus-visible { outline: 2px solid var(--color-accent-purple); outline-offset: 3px; border-radius: 50%; }
.guide-info-links {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 28px;
    margin-top: 10px;
}
.guide-info-links a {
    min-height: 40px;
    padding: 8px 3px;
    border-bottom: 1px solid transparent;
    color: color-mix(in srgb, var(--color-text-light) 78%, transparent);
    font-size: 15px;
    font-weight: 600;
    line-height: 1.5;
}
.guide-info-links a:hover { border-bottom-color: var(--color-accent-purple); color: var(--color-text-light); }
.guide-info-links a:focus-visible { outline: 2px solid var(--color-accent-purple); outline-offset: 3px; border-radius: 3px; }

@media (max-width: 760px) {
    .about-dialog { max-width: calc(100vw - 16px); max-height: calc(100dvh - 16px); }
    .about-stage { width: min(calc(100vw - 38px), calc((100dvh - 104px) * 9 / 16)); }
    .guide-info-links { gap: 26px; }
    .guide-info-links a { min-height: 38px; padding-block: 7px; font-size: 14.5px; }
}

@media (max-width: 520px) {
    .section-heading.has-intro-action { gap: 12px; }
}

@media (orientation: landscape) and (max-height: 520px) {
    .about-stage { width: min(calc(100vw - 56px), calc((100dvh - 80px) * 9 / 16)); }
    .guide-info-links { margin-top: 2px; }
}