:root {
    --main-bg: #ffffff;
    --txt-black: #0f0f0f;
    --txt-gray: #606060;
    --yt-white: #ffffff;
    --line: rgba(0, 0, 0, 0.1);
    --yt-font: "Roboto", sans-serif;
}

body,
.gallery-detail-body {
    margin: 0;
    padding: 0;
    font-family: var(--yt-font);
    background-color: var(--main-bg);
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

/* Base Layout */
.bd-shell__page-content.gallery-page {
    position: relative;
    min-height: calc(100vh - 56px);
    margin-top: 56px;
    margin-left: 240px;
    background: #ffffff;
    overflow-x: hidden;
}

.gallery-container {
    max-width: 100%;
}

#page-manager,
ytd-browse,
ytd-two-column-browse-results-renderer,
#primary,
ytd-rich-grid-renderer {
    display: block;
}

.gallery-page-manager,
.gallery-browse,
.gallery-results,
.gallery-results-primary,
.gallery-rich-grid,
.gallery-rich-grid-contents {
    display: block;
}

.content-row-section {
    padding: 40px 48px 56px;
}

/* [핵심] 50/50 무한 페이드 배너 스타일 */
ytd-carousel-header-renderer,
.gallery-carousel-header {
    display: block;
    width: 100%;
    background-color: #000; /* 전체 배경을 짙은 검은색으로 고정 */
}

#header.ytd-browse,
.gallery-header {
    position: relative;
}

.gallery-top-actions {
    position: absolute;
    top: 18px;
    right: 24px;
    z-index: 10;
    display: flex;
    align-items: center;
    gap: 8px;
}

.gallery-top-action-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: 0;
    border-radius: 999px;
    background: inherit;
    color: #ffffff;
    cursor: pointer;
    backdrop-filter: blur(10px);
}

.gallery-top-action-button:hover {
    background: rgba(255, 255, 255, 0.18);
}

.gallery-top-action-button svg {
    width: 24px;
    height: 24px;
    fill: currentColor;
}

ytd-default-promo-panel-renderer,
.gallery-promo-panel {
    display: flex;
    position: relative;
    width: 100%;
    height: 420px;
    background-color: #000;
    overflow: hidden;
}

/* 우측 사진 영역: 마스크 기법을 사용하여 왼쪽으로 갈수록 투명하게 소멸 */
#hero,
.gallery-hero {
    position: absolute;
    top: 0;
    right: 0;
    width: 70%; /* 페이드 구간 확보를 위해 50%보다 넓게 설정 */
    height: 100%;
    background-size: cover;
    background-position: center;
    z-index: 1;
    /* 사진이 더 넓게 보이도록 페이드 구간을 줄임 */
    -webkit-mask-image: linear-gradient(to right, transparent 0%, rgba(0,0,0,0.18) 18%, rgba(0,0,0,0.72) 34%, black 48%);
    mask-image: linear-gradient(to right, transparent 0%, rgba(0,0,0,0.18) 18%, rgba(0,0,0,0.72) 34%, black 48%);
}

/* 텍스트 가독성을 위한 전체적인 어두운 톤 유지 */
#scrim,
.gallery-scrim {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.1); /* 사진이 더 잘 보이도록 어둡기 완화 */
    z-index: 2;
}

/* 좌측 콘텐츠 영역: 검은색 배경 위에 배치 */
#content.ytd-default-promo-panel-renderer,
.gallery-promo-content {
    position: relative;
    z-index: 3;
    width: 50%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 0 80px;
    box-sizing: border-box;
    color: #fff;
    background-color: transparent; /* 배경은 부모의 #000을 따름 */
}

.promo-text-wrapper {
    width: 100%;
}

#description.style-scope,
.gallery-description {
    display: block;
    font-size: 15px;
    font-weight: 500;
    color: #ffffff;
    margin: 0 0 12px;
    text-transform: uppercase;
    letter-spacing: 2px;
}

#hero-title.ytd-default-promo-panel-renderer,
.gallery-hero-title {
    font-size: 35px;
    font-weight: 800;
    margin: 0 0 32px 0;
    line-height: 1.1;
    letter-spacing: -1px;
    color: #ffffff;
}

.gallery-hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 0 0 14px;
}

.gallery-hero-tag {
    display: inline-flex;
    align-items: center;
    max-width: 180px;
    min-height: 30px;
    padding: 0 12px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.16);
    color: #ffffff;
    font-size: 13px;
    font-weight: 700;
    text-decoration: none;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.gallery-hero-tag:hover {
    background: rgba(255, 255, 255, 0.24);
}

.hero-meta {
    margin: 0 0 24px;
    font-size: 15px;
    font-weight: 500;
    color: #ffffff;
    letter-spacing: -0.01em;
}

.btn-play-all-main {
    background-color: var(--yt-white);
    color: #000;
    border: none;
    border-radius: 24px;
    padding: 0 32px;
    height: 48px;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    margin-bottom: 60px;
    transition: transform 0.2s, background-color 0.2s;
}

.btn-play-all-main:hover {
    background-color: #f2f2f2;
    transform: scale(1.05);
}

/* 하단 썸네일 내비게이션 */
#pagination-thumbnails {
    display: flex;
    gap: 12px;
}

#pagination-thumbnails button {
    background: transparent;
    border: none;
    padding: 0;
    cursor: pointer;
    width: 90px;
    opacity: 0.4;
    transition: opacity 0.3s, transform 0.2s;
}

#pagination-thumbnails button.selected {
    opacity: 1;
    transform: scale(1.1);
}

.thumb-img-wrapper {
    width: 100%;
    aspect-ratio: 16 / 9;
    border-radius: 6px;
    overflow: hidden;
    margin-bottom: 8px;
    border: 1px solid rgba(255,255,255,0.2);
}

.thumb-img-wrapper img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.progress-bar {
    width: 100%;
    height: 3px;
    background-color: rgba(255,255,255,0.2);
    border-radius: 2px;
    overflow: hidden;
}

button.selected .progress-bar::after {
    content: '';
    display: block;
    height: 100%;
    width: 100%;
    background-color: #fff;
    animation: yt-progress 7500ms linear forwards;
}

@keyframes yt-progress {
    from { width: 0; }
    to { width: 100%; }
}

/* Navigation Tabs */
.gallery-nav {
    border-bottom: 1px solid var(--line);
    background: var(--main-bg);
}

.gallery-nav ul {
    list-style: none;
    padding: 0 80px;
    margin: 0;
    display: flex;
    height: 56px;
    align-items: center;
    gap: 40px;
}

.gallery-nav li {
    font-size: 15px;
    font-weight: 600;
    color: var(--txt-gray);
    cursor: pointer;
    position: relative;
    height: 100%;
    display: flex;
    align-items: center;
}

.gallery-nav li.active {
    color: var(--txt-black);
}

.gallery-nav li.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: #0f0f0f;
}

/* Contents Section */
.gallery-content {
    padding: 40px 80px;
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 24px;
    margin-top: 24px;
}

.shorts-grid {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}

.video-item .thumb {
    width: 100%;
    aspect-ratio: 16 / 9;
    border-radius: 12px;
    overflow: hidden;
    background-color: #eee;
    margin-bottom: 12px;
}

.shorts-thumb {
    aspect-ratio: 9 / 16 !important;
}

.video-item .thumb img,
.video-item .thumb video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.video-item .thumb video {
    background: #000000;
}

.item-meta {
    display: grid;
    grid-template-columns: 36px minmax(0, 1fr);
    gap: 12px;
    align-items: start;
    margin-top: 12px;
}

.item-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    overflow: hidden;
    background: #d9d9d9;
}

.item-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.item-copy {
    min-width: 0;
}

.item-meta h3 {
    font-size: 16px;
    font-weight: 600;
    line-height: 1.4;
    margin: 0 0 2px;
    display: -webkit-box;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: 2;
    overflow: hidden;
}

.item-meta p {
    margin: 0;
}

.item-channel,
.item-stats {
    font-size: 14px;
    color: #111111;
    line-height: 1.35;
}

.item-channel {
    margin-bottom: 1px;
}

.video-item,
.video-item:hover,
.video-item:visited,
.item-meta h3,
.item-channel,
.item-stats {
    color: #111111;
    text-decoration: none;
}

ytd-rich-shelf-renderer h2, .content-row-section h2 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 20px;
}

/* Responsive */
@media (max-width: 1024px) {
    .bd-shell__page-content.gallery-page {
        margin-left: 72px;
    }

    #content.ytd-default-promo-panel-renderer { padding: 0 40px; }
    .gallery-promo-content { padding: 0 40px; }
    .gallery-nav ul, .gallery-content { padding-left: 40px; padding-right: 40px; }
    .content-row-section { padding: 32px 32px 48px; }
    .video-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (max-width: 768px) {
    .bd-shell__page-content.gallery-page {
        margin-left: 0;
    }

    ytd-default-promo-panel-renderer { height: 320px; }
    .gallery-promo-panel { height: 320px; }
    #hero { width: 100%; -webkit-mask-image: linear-gradient(to bottom, transparent 0%, black 50%); }
    .gallery-hero { width: 100%; -webkit-mask-image: linear-gradient(to bottom, transparent 0%, black 50%); mask-image: linear-gradient(to bottom, transparent 0%, black 50%); }
    #content.ytd-default-promo-panel-renderer { width: 100%; align-items: center; text-align: center; }
    .gallery-promo-content { width: 100%; align-items: center; text-align: center; }
    .content-row-section { padding: 24px 20px 36px; }
    .video-grid { grid-template-columns: minmax(0, 1fr); }
    .gallery-top-actions { top: 16px; right: 16px; }
}

@media (max-width: 640px) {
    .gallery-top-actions { top: 14px; right: 12px; }
}

.work-action-sheet {
    position: fixed;
    top: 72px;
    right: 24px;
    left: auto;
    z-index: 30;
    width: 180px;
    border: 1px solid #e6e6e6;
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.98);
    color: #111111;
    box-shadow: none;
}

.work-action-sheet button.danger {
    color: #ed4956;
    font-weight: 600;
}
.work-action-sheet button {
    width: 100%;
    border: none;
    background: transparent;
    text-align: center;
    padding: 14px 0;
    font-size: 14px;
    color: #262626;
    cursor: pointer;
    line-height: 1.5;
}
.work-action-sheet button + button {
    border-top: 1px solid #efefef;
}
.work-action-sheet button.cancel{
    color: #262626;
}

.work-action-sheet button + button {
    border-top: 1px solid #efefef;
}

@media (max-width: 768px) {
    .work-action-sheet {
        top: 112px;
        right: 16px;
    }
}