* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    /* Material Design 3 Light Theme Colors */
    --md-primary: #006495;
    --md-on-primary: #ffffff;
    --md-primary-container: #94c6fd;
    --md-on-primary-container: #001e31;
    --md-secondary: #4f616e;
    --md-on-secondary: #ffffff;
    --md-secondary-container: #d3e5f5;
    --md-on-secondary-container: #0b1d29;
    --md-surface: #fcfcff;
    --md-surface-dim: #f8f9ff;
    --md-surface-container: #f3f3f6;
    --md-surface-bright: #fcfcff;
    --md-surface-container-lowest: #ffffff;
    --md-surface-container-low: #f5f5f8;
    --md-surface-container-high: #e9e9ec;
    --md-surface-container-highest: #e3e3e6;
    --md-on-surface: #191c1e;
    --md-outline: #72787e;
    --md-error: #ba1a1a;
    
    /* Map our variables to Material Design */
    --bg-color: var(--md-surface);
    --text-color: var(--md-on-surface);
    --card-bg: var(--md-surface-container-low);
    --card-bg-hover: var(--md-surface-container-high);
    --video-bg: var(--md-surface-container-lowest);
    --card-shadow: 0 1px 3px 1px rgba(0,0,0,0.15), 0 1px 2px 0 rgba(0,0,0,0.3);
    --card-shadow-hover: 0 4px 8px 3px rgba(0,0,0,0.15), 0 1px 3px 0 rgba(0,0,0,0.3);
    --tag-bg: var(--md-secondary-container);
    --tag-hover: var(--md-primary-container);
    --tag-active: var(--md-primary);
    --tag-active-text: var(--md-on-primary);
    --notification-bg: var(--md-primary);
    --notification-text: var(--md-on-primary);
    --search-border: var(--md-outline);
    --heart-color: var(--md-surface-container-highest);
    --heart-active: #e92e44;
    --toggle-bg: var(--md-secondary-container);
    --toggle-circle: var(--md-primary);
    --video-shadow-opacity: 0.3;
}

.dark-theme {
    /* Material Design 3 Dark Theme Colors */
    --md-primary: #8fcdff;
    --md-on-primary: #003450;
    --md-primary-container: #004b71;
    --md-on-primary-container: #cde5ff;
    --md-secondary: #b7c9d9;
    --md-on-secondary: #21323f;
    --md-secondary-container: #374956;
    --md-on-secondary-container: #d3e5f5;
    --md-surface: #191c1e;
    --md-surface-dim: #101214;
    --md-surface-container: #1d2022;
    --md-surface-bright: #393d3f;
    --md-surface-container-lowest: #0c0e10;
    --md-surface-container-low: #191c1e;
    --md-surface-container-high: #272a2c;
    --md-surface-container-highest: #323537;
    --md-on-surface: #e1e2e5;
    --md-outline: #8b9198;
    
    /* Map our variables to Material Design dark theme */
    --bg-color: var(--md-surface);
    --text-color: var(--md-on-surface);
    --card-bg: var(--md-surface-container-low);
    --card-bg-hover: var(--md-surface-container);
    --video-bg: var(--md-surface-container-lowest);
    --card-shadow: 0 1px 3px rgba(0,0,0,0.5);
    --tag-bg: var(--md-secondary-container);
    --tag-hover: var(--md-primary-container);
    --tag-active: var(--md-primary);
    --tag-active-text: var(--md-on-primary);
    --notification-bg: var(--md-primary);
    --notification-text: var(--md-on-primary);
    --search-border: var(--md-outline);
    --heart-color: var(--md-surface-container-highest);
    --heart-active: #ff3e40;
    --toggle-bg: var(--md-secondary-container);
    --toggle-circle: var(--md-primary);
    --video-shadow-opacity: 0.6;

    /* Dark theme specific button styles */
    .clear-filter {
        background-color: #ba1a1a;
        color: #ffffff;
    }

    .clear-filter:hover {
        background-color: #93000a;
    }

    .favorites-filter {
        background-color: #e92e44;
        color: #ffffff;
    }

    .favorites-filter:hover {
        background-color: #ba1a2e;
    }
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    padding: 10px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.title-section {
    flex: 1;
}

.toggle-section {
    display: flex;
    align-items: center;
    gap: 10px;
}

.theme-toggle {
    position: relative;
    width: 50px;
    height: 24px;
    background-color: var(--toggle-bg);
    border-radius: 12px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.theme-toggle-circle {
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background-color: var(--toggle-circle);
    border-radius: 50%;
    transition: transform 0.3s ease;
}

.theme-toggle.dark .theme-toggle-circle {
    transform: translateX(26px);
}

.search-container {
    width: 100%;
}

.search-container input {
    width: 100%;
    padding: 8px;
    border: 1px solid var(--search-border);
    border-radius: 4px;
    background-color: white;
    color: var(--text-color);
    transition: border-color 0.3s ease;
}

.search-container input:focus {
    outline: none;
    border-color: var(--tag-active);
}

/* Dark theme specific override */
.dark-theme .search-container input {
    background-color: #333;
    color: #eee;
}

.tags-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 15px;
    padding: 10px;
    background-color: var(--card-bg);
    border-radius: 8px;
    box-shadow: var(--card-shadow);
}

.filter-controls {
    display: flex;
    gap: 5px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--search-border);
}

.tags-list {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
}

.tag {
    padding: 4px 8px;
    background-color: var(--tag-bg);
    border-radius: 20px;
    cursor: pointer;
    transition: background-color 0.2s cubic-bezier(0.4, 0, 0.2, 1),
                color 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    color: var(--text-color);
}

.tag:hover {
    background-color: var(--tag-hover);
}

.tag.active {
    background-color: var(--tag-active);
    color: var(--tag-active-text);
}

.hidden {
    display: none;
}

/* Animation classes for elements */
.element {
    background: var(--card-bg);
    border-radius: 16px;
    box-shadow: var(--card-shadow);
    border: none;
    transition: box-shadow 0.3s ease-in-out,
                background-color 0.3s ease-in-out,
                opacity 0.3s ease-in-out,
                transform 0.3s ease-in-out;
    cursor: pointer;
    padding: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    opacity: 1;
    transform: translateZ(0);
    animation: fadeIn 0.3s ease-in-out;
    will-change: transform, opacity;
    backface-visibility: hidden;
    z-index: 3;
    
    /* Add containment for performance */
    contain: layout style paint;
    content-visibility: auto;
    contain-intrinsic-size: 0 300px; /* Approximate size to avoid layout shifts */
}

@keyframes fadeIn {
    from { 
        opacity: 0; 
    }
    to { 
        opacity: 1; 
    }
}

.element:hover {
    box-shadow: var(--card-shadow-hover);
    background: var(--card-bg-hover);
}

.element:hover .video-container {
    transform: none;
}

.element.hidden {
    display: none;
}

.favorite-icon {
    cursor: pointer;
    width: 24px;
    height: 24px;
    display: inline-flex;
    vertical-align: middle;
    margin-left: 8px;
}

.favorite-icon svg {
    fill: var(--heart-color);
    transition: fill 0.3s ease;
    stroke: var(--text-color);
    stroke-width: 1;
}

.favorite-icon.active svg {
    fill: var(--heart-active);
    stroke: var(--heart-active);
}

.video-container {
    width: 100%;
    border-radius: 8px;
    overflow: hidden;
    margin-bottom: 12px;
    background-color: var(--video-bg);
    transition: transform 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    z-index: 3;
    will-change: transform;
    
    /* Add containment for video container */
    contain: layout paint;
}

.video-container::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    box-shadow: inset 0 1px 8px rgba(0,0,0,var(--video-shadow-opacity));
    pointer-events: none;
    border-radius: 8px;
}

.element video {
    width: auto;
    height: auto;
    max-width: 100%;
    max-height: 300px;
}

.title-container {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    border-top: 1px solid var(--card-border);
    margin-top: auto;
}

.title-container h3 {
    margin: 0;
    font-size: 0.9rem;
    font-weight: 400;
    letter-spacing: 0.2px;
    color: var(--text-color);
    text-align: center;
    flex-grow: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1;
    position: relative;
    top: -1px;
    text-shadow: 0 0.5px 1px rgba(0, 0, 0, 0.1);
}

.bg-switcher {
    display: flex;
    gap: 4px;
    padding: 4px;
    background-color: var(--md-surface-container-highest);
    border-radius: 20px;
    box-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

.bg-option {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.bg-option:hover {
    transform: scale(1.1);
}

.bg-option.active {
    border-color: var(--tag-active);
    transform: scale(1.1);
}

/* Add specific style for background variant */
.bg-option[data-variant="bg"] {
    background-image: linear-gradient(45deg, rgba(0,0,0,0.45) 25%, rgba(0,0,0,0.2) 25%, rgba(0,0,0,0.2) 50%, rgba(0,0,0,0.45) 50%, rgba(0,0,0,0.45) 75%, rgba(0,0,0,0.2) 75%, rgba(0,0,0,0.2));
    background-size: 1.5px 1.5px;
}

.notification {
    position: fixed;
    bottom: 20px;
    right: 20px;
    padding: 10px 20px;
    background-color: var(--notification-bg);
    color: var(--notification-text);
    border-radius: 8px;
    box-shadow: 0 3px 6px rgba(0,0,0,0.15), 0 2px 4px rgba(0,0,0,0.3);
    transform: translateY(100px);
    opacity: 0;
    transition: all 0.3s ease;
}

.notification.show {
    transform: translateY(0);
    opacity: 1;
}

.clear-filter {
    background-color: #ba1a1a;
    color: #ffffff;
}

.clear-filter:hover {
    background-color: #93000a;
}

.favorites-filter {
    background-color: #e92e44;
    color: #ffffff;
}

.favorites-filter:hover {
    background-color: #ba1a2e;
}

.elements-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 10px;
    position: relative;
    min-height: 100px; /* Prevents container collapse during filtering */
    
    /* Add containment for the container */
    contain: layout style;
}

@keyframes floatingHeart {
    0% {
        transform: translate(0, 0) scale(0.2);
        opacity: 0;
    }
    20% {
        opacity: 0.8;
    }
    100% {
        transform: translate(var(--tx), calc(var(--ty) * -1)) scale(0.8) rotate(var(--rot));
        opacity: 0;
    }
}

.floating-heart {
    position: fixed;
    color: #ff3e40; /* Fallback for browsers without CSS var support */
    color: var(--heart-active);
    pointer-events: none;
    animation: floatingHeart 10s ease-out forwards;
    z-index: -1;  /* Changed from 2 to -1 so hearts appear behind elements */
    font-size: 24px;
    will-change: transform, opacity;
    /* For GPU acceleration on modern browsers */
}

/* Loading indicator */
.loading-indicator {
    text-align: center;
    padding: 20px;
    font-size: 1.2rem;
    color: var(--text-color);
    width: 100%;
    animation: pulse 1.5s infinite;
}

@keyframes pulse {
    0% { opacity: 0.6; }
    50% { opacity: 1; }
    100% { opacity: 0.6; }
}

/* Placeholder elements styling */
.placeholder-element {
    background: var(--card-bg);
    animation: pulse-bg 2s infinite ease-in-out;
}

.placeholder-element .video-container {
    background: var(--video-bg);
    animation: pulse-content 2s infinite ease-in-out;
}

.placeholder-element .title-container div {
    animation: pulse-content 2s infinite ease-in-out;
    animation-delay: 0.3s;
}

@keyframes pulse-bg {
    0%, 100% { background-color: var(--card-bg); }
    50% { background-color: var(--card-bg-hover); }
}

@keyframes pulse-content {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 0.8; }
}

/* Video loading states and placeholders */
.video-placeholder {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--video-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.video-placeholder.loading {
    opacity: 1;
}

.video-placeholder.loading::after {
    content: "";
    width: 30px;
    height: 30px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: var(--text-color);
    animation: spin 1s infinite linear;
}

.video-placeholder.loaded {
    opacity: 0;
    pointer-events: none;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Video loading transitions */
.video-container {
    position: relative;
    overflow: hidden;
}

.video-loading {
    opacity: 0;
    transition: opacity 0.5s ease-in;
}

.video-loaded {
    opacity: 1 !important;
}

/* Video error state */
.video-error {
    position: relative;
    background: var(--card-bg-hover);
}

.video-error-message {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: var(--text-color);
    background: rgba(0, 0, 0, 0.5);
    padding: 8px 12px;
    border-radius: 4px;
    font-size: 0.9rem;
}

/* Override animation for elements that have inline style opacity */
.element[style*="opacity"] {
    animation: none !important;
}