/* ============================================
   Category Page - Liquid Glass 风格
   iOS 26 inspired - 透明、流动、亮丽
   ============================================ */

/* 页面背景 - 柔和渐变 */
.yt-main {
    background: linear-gradient(145deg, 
        #e0f2fe 0%, 
        #f0fdfa 25%,
        #fdf4ff 50%,
        #fef3c7 75%,
        #e0f2fe 100%);
    background-size: 400% 400%;
    animation: bgFlow 20s ease infinite;
    min-height: 100vh;
}

@keyframes bgFlow {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

/* Category Card 容器 */
.category-card {
    position: relative;
    margin-bottom: 32px;
}

/* Banner - 彩色渐变背景 */
.category-banner {
    width: 100%;
    height: 400px;
    min-height: 400px;
    max-height: 400px;
    background: linear-gradient(135deg, 
        #06b6d4 0%, 
        #8b5cf6 25%,
        #ec4899 50%,
        #f97316 75%,
        #06b6d4 100%);
    background-size: 300% 300%;
    animation: bannerFlow 12s ease infinite;
    position: relative;
    overflow: hidden;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
}

@keyframes bannerFlow {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

/* 玻璃光泽层 */
.category-banner::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(ellipse 80% 50% at 20% 40%, rgba(255,255,255,0.4) 0%, transparent 50%),
        radial-gradient(ellipse 60% 40% at 80% 60%, rgba(255,255,255,0.3) 0%, transparent 50%);
    pointer-events: none;
}

/* 底部渐变 */
.category-banner::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 150px;
    background: linear-gradient(to top, rgba(255,255,255,0.2) 0%, transparent 100%);
}

/* Category Header - Liquid Glass 卡片 */
.category-header {
    position: relative;
    z-index: 10;
    margin: -120px 40px 0;
    padding: 32px 36px;
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(40px) saturate(180%);
    -webkit-backdrop-filter: blur(40px) saturate(180%);
    border-radius: 28px;
    border: 1px solid rgba(255, 255, 255, 0.7);
    box-shadow: 
        0 8px 32px rgba(0, 0, 0, 0.08),
        0 0 0 1px rgba(255, 255, 255, 0.5) inset,
        0 2px 4px rgba(255, 255, 255, 0.9) inset;
    display: flex;
    gap: 28px;
    align-items: flex-start;
}

/* 玻璃高光 */
.category-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 20px;
    right: 20px;
    height: 1px;
    background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.9) 50%, transparent 100%);
}

/* Category Avatar - 玻璃图标 */
.category-avatar {
    width: 140px;
    height: 140px;
    min-width: 140px;
    min-height: 140px;
    background: linear-gradient(145deg, 
        rgba(6, 182, 212, 0.8) 0%, 
        rgba(139, 92, 246, 0.8) 50%,
        rgba(236, 72, 153, 0.8) 100%);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    border: 1px solid rgba(255, 255, 255, 0.5);
    box-shadow: 
        0 8px 24px rgba(139, 92, 246, 0.3),
        0 0 0 1px rgba(255, 255, 255, 0.3) inset,
        0 1px 2px rgba(255, 255, 255, 0.8) inset;
    position: relative;
    overflow: hidden;
}

.category-avatar::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 50%;
    background: linear-gradient(to bottom, rgba(255,255,255,0.4) 0%, transparent 100%);
    border-radius: 22px 22px 50% 50%;
}

.category-avatar svg {
    width: 64px;
    height: 64px;
    color: white;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.15));
    position: relative;
    z-index: 1;
}

.category-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 24px;
}

/* Category Info */
.category-info {
    flex: 1;
}

.category-title {
    font-size: 32px;
    font-weight: 700;
    color: #1e293b;
    margin: 0 0 8px 0;
    line-height: 1.3;
    letter-spacing: -0.3px;
    min-height: 42px;
    display: flex;
    align-items: center;
}

.category-subtitle {
    font-size: 13px;
    color: #64748b;
    margin: 0 0 10px 0;
    font-weight: 500;
}

.category-description {
    font-size: 14px;
    color: #475569;
    line-height: 1.6;
    margin: 0;
    max-width: 600px;
}

/* Stats */
.category-stats {
    display: flex;
    gap: 12px;
    flex-shrink: 0;
}

.category-stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 12px 18px;
    background: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.6);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
    min-width: 80px;
}

.category-stat-item svg {
    display: none;
}

.category-stat-number {
    font-size: 20px;
    font-weight: 700;
    color: #0f172a;
    line-height: 1;
}

.category-stat-item span {
    font-size: 11px;
    color: #64748b;
    margin-top: 4px;
}

/* ============================================
   Navigation - Liquid Glass Tabs
   ============================================ */

.category-nav {
    margin: 24px 40px 32px;
    padding: 6px;
    background: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(40px) saturate(180%);
    -webkit-backdrop-filter: blur(40px) saturate(180%);
    border-radius: 18px;
    border: 1px solid rgba(255, 255, 255, 0.6);
    box-shadow: 
        0 4px 16px rgba(0, 0, 0, 0.06),
        0 0 0 1px rgba(255, 255, 255, 0.4) inset;
}

.category-tabs {
    display: flex;
    gap: 6px;
}

.category-tab {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 18px;
    background: transparent;
    border: none;
    border-radius: 12px;
    color: #64748b;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    white-space: nowrap;
}

.category-tab:hover {
    color: #334155;
    background: rgba(255, 255, 255, 0.5);
}

.category-tab.active {
    background: rgba(255, 255, 255, 0.85);
    color: #0f172a;
    font-weight: 600;
    box-shadow: 
        0 2px 8px rgba(0, 0, 0, 0.08),
        0 0 0 1px rgba(255, 255, 255, 0.5) inset;
}

.category-tab svg {
    width: 16px;
    height: 16px;
}

/* ============================================
   Video Grid
   ============================================ */

.yt-video-grid {
    margin: 0 40px 80px;
    padding: 0;
}

/* 去掉默认标题 */
.yt-video-grid::before {
    display: none;
}

/* Loading & Empty - Liquid Glass */
.yt-loading {
    text-align: center;
    padding: 60px 20px;
    color: #64748b;
    font-size: 14px;
}

.yt-empty {
    text-align: center;
    padding: 80px 32px;
    background: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(40px);
    -webkit-backdrop-filter: blur(40px);
    border-radius: 24px;
    border: 1px solid rgba(255, 255, 255, 0.6);
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
}

.yt-empty svg {
    width: 64px;
    height: 64px;
    color: #94a3b8;
    margin-bottom: 16px;
}

.yt-empty h3 {
    font-size: 17px;
    font-weight: 600;
    color: #334155;
    margin: 0 0 6px 0;
}

.yt-empty p {
    font-size: 14px;
    color: #64748b;
    margin: 0;
}

/* ============================================
   Video Card V2 - Liquid Glass 覆盖
   ============================================ */

.video-grid-v2 {
    padding: 0;
}

.video-grid-v2 .video-card-v2 {
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(40px) saturate(180%);
    -webkit-backdrop-filter: blur(40px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.7);
    box-shadow: 
        0 4px 16px rgba(0, 0, 0, 0.06),
        0 0 0 1px rgba(255, 255, 255, 0.4) inset;
    border-radius: 20px;
}

.video-grid-v2 .video-card-v2:hover {
    transform: translateY(-4px) scale(1.01);
    box-shadow: 
        0 12px 32px rgba(0, 0, 0, 0.1),
        0 0 0 1px rgba(255, 255, 255, 0.5) inset;
}

.video-grid-v2 .video-card-v2 .thumb {
    border-radius: 16px 16px 0 0;
}

.video-grid-v2 .video-card-v2 .content {
    background: transparent;
    border-top: 1px solid rgba(255, 255, 255, 0.5);
}

/* ============================================
   Responsive
   ============================================ */

@media (max-width: 1024px) {
    .category-header {
        margin: -80px 24px 0;
        padding: 28px 28px;
    }
    
    .category-nav {
        margin: 20px 24px 28px;
    }
    
    .yt-video-grid {
        margin: 0 24px 60px;
    }
}

@media (max-width: 768px) {
    .category-banner {
        height: 240px;
    }
    
    .category-header {
        margin: -70px 16px 0;
        padding: 24px 20px;
        flex-direction: column;
        align-items: flex-start;
        gap: 20px;
        border-radius: 24px;
    }
    
    .category-avatar {
        width: 72px;
        height: 72px;
        border-radius: 18px;
    }
    
    .category-avatar svg {
        width: 32px;
        height: 32px;
    }
    
    .category-title {
        font-size: 22px;
    }
    
    .category-stats {
        width: 100%;
        justify-content: flex-start;
    }
    
    .category-stat-item {
        padding: 10px 14px;
        min-width: 70px;
    }
    
    .category-stat-number {
        font-size: 18px;
    }
    
    .category-nav {
        margin: 16px 16px 24px;
        padding: 5px;
        border-radius: 14px;
    }
    
    .category-tabs {
        flex-wrap: wrap;
    }
    
    .category-tab {
        padding: 8px 14px;
        font-size: 13px;
        border-radius: 10px;
    }
    
    .yt-video-grid {
        margin: 0 16px 50px;
    }
}

@media (max-width: 480px) {
    .category-banner {
        height: 200px;
    }
    
    .category-header {
        margin: -60px 12px 0;
        padding: 20px 16px;
        border-radius: 20px;
    }
    
    .category-avatar {
        width: 60px;
        height: 60px;
        border-radius: 16px;
    }
    
    .category-title {
        font-size: 20px;
    }
    
    .category-description {
        font-size: 13px;
    }
    
    .category-nav {
        margin: 12px 12px 20px;
    }
    
    .yt-video-grid {
        margin: 0 12px 40px;
    }
}

/* Sidebar */
.yt-sidebar-section-items a.active {
    background: rgba(6, 182, 212, 0.1);
    color: #0891b2;
    font-weight: 500;
}