html, body, .content, #lesson-view, #lesson-iframe {
    height: 100% !important;
    margin: 0 !important;
    padding: 0 !important;
}

html {
    transition: background-color 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                color 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    color-scheme: dark;
}

:root {
    --color-primary-bg: #000000;
    --color-secondary-bg: #000000;
    --color-accent-main: #ffffff;
    --color-accent-hover: #ffffff;
    --color-text: #ffffff;
    --color-border: #ffffff;

    --space-sm: 0.5rem;
    --space-md: 0.75rem;
    --space-lg: 1rem;
    --space-xl: 1.5rem;

    --border-subtle:  rgba(255, 255, 255, 0.10);
    --border-default: rgba(255, 255, 255, 0.18);
    --border-strong:  rgba(255, 255, 255, 0.30);

    --color-surface:       rgba(255, 255, 255, 0.02);
    --color-surface-hover: rgba(255, 255, 255, 0.08);

    --color-text-muted: rgba(255, 255, 255, 0.60);
    --color-text-dim:   rgba(255, 255, 255, 0.75);
    --color-text-full:  rgba(255, 255, 255, 0.90);

    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Inter', sans-serif;
    display: flex;
    flex-direction: column;
    color: var(--color-text);
    background-color: var(--color-primary-bg);
    overflow: hidden;
    position: relative;
    min-height: 100vh;
}

.content {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.gradient-word {
    background: linear-gradient(to right, #333333, #ffffff, #333333);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    font-weight: 600;
    font-size: 2.2rem;
}

#sidebar {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    height: auto !important;
    width: auto !important;
    z-index: 1000 !important;
    background: rgba(0, 0, 0, 0.3) !important;
    backdrop-filter: blur(40px) saturate(180%);
    -webkit-backdrop-filter: blur(40px) saturate(180%);
    border: 1px solid var(--border-default) !important;
    border-top: 1px solid rgba(255, 255, 255, 0.22) !important;
    border-radius: 16px !important;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: row;
    align-items: center;
    padding: 6px 10px;
}

#sidebar nav { width: auto; padding: 0; }

#sidebar nav ul {
    padding: 0;
    margin: 0;
    list-style: none;
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: 2px;
}

#sidebar nav ul li {
    width: auto;
    display: flex;
    justify-content: center;
}

#home-page-view,
#lessons-view,
#lesson-view,
#s-view,
#e-view {
    margin-left: 0 !important;
    width: 100% !important;
    height: 100vh !important;
    overflow-y: auto;
    overflow-x: hidden;
    position: relative;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    align-items: center;
    content-visibility: auto;
    contain-intrinsic-size: auto 100vh;
    padding-bottom: 90px !important;
}

#home-page-view.hidden-view,
#lessons-view.hidden-view,
#lesson-view.hidden-view,
#s-view.hidden-view,
#e-view.hidden-view {
    display: none !important;
    visibility: hidden !important;
    pointer-events: none !important;
    opacity: 0 !important;
    content-visibility: hidden !important;
}

.hidden-view,
.hidden-view * {
    display: none !important;
    visibility: hidden !important;
    pointer-events: none !important;
}

.hidden-view {
    position: absolute !important;
    top: -9999px !important;
    left: -9999px !important;
    opacity: 0 !important;
    z-index: -1 !important;
}

.hidden-view img,
.hidden-view video,
.hidden-view iframe,
.hidden-view canvas {
    content-visibility: hidden !important;
    display: none !important;
}

.hidden-view iframe,
.hidden-view #lesson-iframe {
    display: none !important;
    visibility: hidden !important;
    content-visibility: hidden !important;
    pointer-events: none !important;
    opacity: 0 !important;
    position: absolute !important;
    top: -9999px !important;
    left: -9999px !important;
}

.hidden-view iframe *,
.hidden-view #lesson-iframe * {
    animation-play-state: paused !important;
    transition: none !important;
}

/* ── Lesson view ── */
#lesson-view {
    display: flex;
    flex-direction: column;
    background-color: var(--color-secondary-bg);
    position: relative;
    content-visibility: auto;
    contain-intrinsic-size: auto 100vh;
    contain: strict;
    isolation: isolate;
    padding-bottom: 0 !important;
}

#lesson-view:not(.hidden-view) { contain: layout style paint; }

#lesson-view * {
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

#lesson-iframe {
    flex-grow: 1;
    width: 100%;
    border: none;
    background-color: var(--color-primary-bg);
    transform: translateZ(0);
    contain: strict;
    isolation: isolate;
    /* Removed invalid will-change: contents */
}

#lesson-view.loading #lesson-iframe { filter: none; }

/* ── Game grid ── */
#lesson-box-wrapper {
    display: grid !important;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)) !important;
    gap: 16px !important;
    padding: 2rem !important;
    max-width: 1400px !important;
    width: 100% !important;
    margin: 0 auto !important;
    box-sizing: border-box;
    justify-content: center;
    contain: layout style;
}

#lesson-box-wrapper p,
.game-grid p {
    grid-column: 1 / -1;
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.95rem;
    padding: 3rem 1rem;
    margin: 0;
    width: 100%;
}

#lessons-view {
    background: transparent;
    contain: layout style;
    scroll-behavior: auto;
    overflow-anchor: none;
}

#lessons-view .game-box {
    content-visibility: auto;
    contain-intrinsic-size: 160px 120px;
}

.game-grid {
    display: grid !important;
    grid-template-columns: repeat(auto-fill, minmax(160px, 160px)) !important;
    gap: 16px !important;
    padding: 2rem !important;
    box-sizing: border-box;
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    justify-content: center;
    justify-items: center;
}

.game-grid .five-box-row,
.five-box-row { display: contents !important; }

#lesson-box-wrapper,
.game-grid { contain: layout style; }
/* Removed invalid will-change: scroll-position */

.game-box {
    width: 100%;
    aspect-ratio: 4 / 3;
    background-color: rgba(25, 25, 35, 0.6);
    border: none !important;
    border-radius: 16px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    cursor: pointer;
    transition: transform 0.2s cubic-bezier(0.2, 1, 0.3, 1),
                border-color 0.2s ease;
    position: relative;
    box-shadow: none !important;
    transform: translateZ(0);
    /* Removed will-change: transform — too many elements reserving GPU memory */
    contain: layout style paint;
    content-visibility: auto;
    contain-intrinsic-size: 160px 120px;
    margin: 0 !important;
}

.game-box:hover {
    background-color: var(--color-surface-hover);
    border-color: rgba(255, 255, 255, 0.25) !important;
    transform: translateY(-2px) translateZ(0);
}

.game-box:active { transform: translateY(0) translateZ(0); }

.game-box img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: none;
    pointer-events: none;
}

.game-box:hover img { transform: none; }

.game-box img,
.showcase-lesson img,
.mini-preview img {
    content-visibility: auto;
    contain-intrinsic-size: 200px 150px;
    image-rendering: auto;
    transform: translateZ(0);
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

/* Ripple effect */
.game-box::after {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    background: radial-gradient(circle at center, rgba(255,255,255,0.4) 0%, transparent 50%);
    opacity: 0;
    transform: scale(0) translateZ(0);
    border-radius: inherit;
}

.game-box:active::after {
    opacity: 1;
    transform: scale(1.5) translateZ(0);
    animation: confetti-burst 0.6s ease-out forwards;
}

@keyframes confetti-burst {
    to { opacity: 0; transform: scale(2.5) translateZ(0); }
}

@media (hover: none) and (pointer: coarse) {
    .game-box:hover {
        transform: translateY(0) scale(1) translateZ(0);
        background-color: rgba(25, 25, 35, 0.6);
        border-color: var(--border-subtle) !important;
    }
    .game-box:hover img { transform: scale(1); }
    .game-title { opacity: 1; }
}

.game-title {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    font-size: 0.8rem;
    font-weight: 600;
    text-align: center;
    padding: 0.5rem;
    color: #ffffff;
    background: rgba(0,0,0,0);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    opacity: 0;
    transition: opacity 0.2s ease, background-color 0.2s ease;
    pointer-events: none;
}

.game-box:hover .game-title {
    opacity: 1;
    background: rgba(50,50,50,0.55);
    backdrop-filter: blur(0.5px) saturate(140%) brightness(1.05);
    -webkit-backdrop-filter: blur(0.7px) saturate(140%) brightness(1.05);
}

/* ── Responsive grid ── */
@media (max-width: 1200px) {
    #lesson-box-wrapper {
        grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)) !important;
        gap: 14px !important;
    }
    .game-grid { grid-template-columns: repeat(auto-fill, minmax(140px, 140px)) !important; }
    .game-box { border-radius: 14px; }
}

@media (max-width: 768px) {
    #sidebar { bottom: 12px; padding: 4px 6px; border-radius: 14px !important; }

    #home-page-view,
    #lessons-view,
    #lesson-view,
    #s-view,
    #e-view {
        margin-left: 0 !important;
        width: 100% !important;
        height: 100vh !important;
        padding-bottom: 80px !important;
    }

    #lesson-box-wrapper {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)) !important;
        gap: 12px !important;
        padding: 1.5rem !important;
    }

    .game-grid {
        grid-template-columns: repeat(auto-fill, minmax(120px, 120px)) !important;
        gap: 8px !important;
        padding: 1rem !important;
    }

    .game-box { border-radius: var(--radius-md); }
    .game-title { font-size: 0.7rem; padding: 0.35rem; }

    .e-container { grid-template-columns: 1fr; gap: 1rem; }
    .e-card { padding: 1.5rem; }

    .search-container { flex-direction: column; gap: 10px; max-width: 100%; padding: 0.75rem; }
    .category-wrapper, .provider-wrapper { width: 100%; }
    .category-toggle { width: 100%; }
    .category-menu { right: 0; left: 0; min-width: auto; }
    .search-wrapper { max-width: 100%; }

    #home-page-view { flex-direction: column; text-align: center; gap: 1.5rem; }
    .typewriter-container { font-size: 1.6rem; }
}

@media (max-width: 480px) {
    #sidebar { bottom: 8px; padding: 4px; }

    #lesson-box-wrapper {
        grid-template-columns: repeat(auto-fill, minmax(100px, 1fr)) !important;
        gap: 10px !important;
        padding: 1rem !important;
    }

    .game-grid {
        grid-template-columns: repeat(auto-fill, minmax(100px, 100px)) !important;
        gap: 6px !important;
        padding: 0.75rem !important;
    }

    .game-box { border-radius: 10px; }

    .popup-content { padding: 30px 20px; width: 95%; }
    .popup-content h2 { font-size: 22px; }
}

/* ── Extra view ── */
#e-view {
    padding: 2rem 1rem;
    justify-content: center;
    background: transparent;
    border: 1px solid var(--border-subtle);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    border-top: 1px solid var(--border-default);
}

.e-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    max-width: 900px;
    width: 100%;
    margin: 0 auto;
}

.e-card {
    background: var(--color-surface);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    padding: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    cursor: pointer;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                background-color 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                border-color 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    border-top: 1px solid rgba(255, 255, 255, 0.20);
    transform: translateZ(0);
    contain: layout style paint;
}

.e-card:hover {
    background: var(--color-surface-hover);
    border-color: var(--border-strong);
    transform: translateY(-4px) translateZ(0);
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.4);
    border-top-color: rgba(255, 255, 255, 0.25);
}

.e-card-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    color: var(--color-text-dim);
}

.e-card-icon svg { width: 24px; height: 24px; stroke-width: 2; }
.e-card h3 { font-size: 1.1rem; font-weight: 600; color: var(--color-text-full); margin-bottom: 0.5rem; }
.e-card p { font-size: 0.85rem; color: var(--color-text-muted); margin: 0; line-height: 1.4; }

/* ── Settings view ── */
#s-view {
    padding: 2rem 1rem;
    max-width: none;
    margin: 0;
    margin-left: 0 !important;
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    min-height: 100vh;
    height: 100vh;
    box-sizing: border-box;
    background: transparent;
    border: 1px solid var(--border-subtle);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    border-top: 1px solid var(--border-default);
    -ms-overflow-style: none;
    scrollbar-width: none;
}

#s-view::-webkit-scrollbar { display: none; width: 0; height: 0; }

#s-view > .s-tabs-container { width: 100%; max-width: 800px; margin-left: auto; margin-right: auto; }

#s-view .tab-panel { padding: 0; width: 100%; max-width: 800px; margin: 0 auto; display: none; opacity: 0; transition: opacity 0.2s ease; }
#s-view .tab-panel.active { display: block; opacity: 1; }

.s-title {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    font-size: 1.2rem;
    font-weight: 500;
    margin-top: 0;
    margin-bottom: 2.5rem;
    color: var(--color-text-full);
    background: none;
    line-height: 1.5;
}

.s-title svg { width: 20px; height: 20px; stroke-width: 2; color: var(--color-text-full); flex-shrink: 0; align-self: center; margin-top: 2px; }
.s-title span { line-height: 1.5; align-self: center; }

.setting-header { display: flex; align-items: center; gap: 0.625rem; margin-bottom: 1rem; }
.setting-header svg { width: 18px; height: 18px; stroke-width: 2; color: var(--color-text-dim); flex-shrink: 0; }
.setting-header label { font-size: 0.9rem; color: var(--color-text-full); font-weight: 500; margin: 0; letter-spacing: 0.01em; }

.setting-item {
    background: var(--color-surface) !important;
    border: 1px solid var(--border-default) !important;
    padding: 1rem;
    border-radius: 8px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    border-top: 1px solid rgba(255, 255, 255, 0.20) !important;
    transition: background-color 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                border-color 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    contain: layout style paint;
}

.setting-item:hover {
    border-color: var(--border-strong) !important;
    background: rgba(255, 255, 255, 0.05) !important;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
    border-top-color: rgba(255, 255, 255, 0.25) !important;
}

.setting-item label { font-size: 0.875rem; color: var(--color-text-dim); font-weight: 500; margin-bottom: 0.625rem; display: block; line-height: 1.5; }
.setting-hint { font-size: 0.8rem; color: var(--color-text-muted); margin-top: 0.625rem; margin-bottom: 0; line-height: 1.5; }
.setting-status { font-size: 0.85rem; color: rgba(34, 197, 94, 0.9); margin-top: 0.75rem; text-align: center; line-height: 1.5; }
.setting-value { text-align: center; margin-top: 0.75rem; font-size: 0.85rem; color: var(--color-text-dim); font-weight: 500; line-height: 1.5; }
.setting-control { display: flex; align-items: center; justify-content: space-between; margin-top: 0.75rem; gap: 1rem; }
.setting-control span { font-size: 0.85rem; color: rgba(255, 255, 255, 0.65); line-height: 1.5; }
.setting-danger .setting-header svg, .setting-danger .setting-header label { color: rgba(239, 68, 68, 0.9); }

.setting-options { margin-top: 1.25rem; padding-top: 1.25rem; border-top: 1px solid var(--border-subtle); }
.setting-options .setting-item { border-bottom: none; padding-bottom: 0; margin-bottom: 1rem; }
.setting-options .setting-item:last-child { margin-bottom: 0; }

/* Tabs */
.s-tabs-container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    margin-left: auto;
    margin-right: auto;
    padding: 0;
    flex-wrap: nowrap;
    -webkit-overflow-scrolling: touch;
    -ms-overflow-style: none;
    scrollbar-width: none;
}

.s-tabs-container::-webkit-scrollbar { display: none; }

.tab-button {
    background: var(--color-surface) !important;
    border: 1px solid var(--border-default) !important;
    border-top: 1px solid rgba(255, 255, 255, 0.12) !important;
    border-radius: var(--radius-sm) !important;
    padding: 0.5rem 1rem;
    font-weight: 500;
    font-size: 0.85rem;
    color: var(--color-text-muted);
    transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    white-space: nowrap;
    flex-shrink: 0;
    contain: layout style paint;
}

.tab-button svg { width: 18px; height: 18px; stroke-width: 2; }

.tab-button.active {
    background: var(--color-surface-hover) !important;
    border-color: var(--border-strong) !important;
    border-top-color: rgba(255, 255, 255, 0.22) !important;
    color: rgba(255, 255, 255, 1);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4) !important;
    transform: none !important;
}

.tab-button.active::after { display: none; }

/* Toggle */
.toggle { position: relative; display: inline-block; width: 44px; height: 24px; }
.toggle input { opacity: 0; width: 0; height: 0; }

.slider {
    position: absolute;
    cursor: pointer;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: var(--border-default);
    border-radius: 24px;
    border: 1px solid var(--border-subtle);
    transition: background-color 0.2s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 18px; width: 18px;
    left: 2px; bottom: 2px;
    background-color: var(--color-text-full);
    border-radius: 50%;
    transition: transform 0.3s cubic-bezier(0.68, -0.55, 0.27, 1.55);
}

input:checked + .slider { background-color: rgba(255,255,255,0.25); border-color: rgba(255,255,255,0.20); transform: scale(1.05); }
input:checked + .slider:before { transform: translateX(20px); }

/* Form inputs */
#s-view select,
#s-view input[type="text"],
#s-view input.panic-input,
#s-view input[type="file"] {
    width: 100%;
    padding: 0.65rem 0.875rem;
    background: rgba(20, 20, 30, 0.5);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    color: var(--color-text-full);
    margin-top: 0.5rem;
    font-size: 0.875rem;
    transition: border-color 0.2s ease, background-color 0.2s ease;
    box-sizing: border-box;
    line-height: 1.5;
}

#s-view select:focus,
#s-view input[type="text"]:focus,
#s-view input.panic-input:focus {
    outline: none;
    border-color: rgba(255, 255, 255, 0.20);
    background-color: rgba(20, 20, 30, 0.6);
}

#s-view input::placeholder { color: var(--color-text-muted); }

input[type="range"] { width: 100%; margin-top: 0.75rem; cursor: pointer; }
input[type="file"] { padding: 0.5rem; cursor: pointer; }

input[type="file"]::file-selector-button {
    padding: 0.5rem 1rem;
    margin-right: 0.75rem;
    background: var(--border-subtle);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    color: var(--color-text-full);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

input[type="file"]::file-selector-button:hover { background: rgba(255,255,255,0.15); border-color: rgba(255,255,255,0.20); }
input[type="range"]::-webkit-slider-thumb { background: rgba(255,255,255,0.8); cursor: pointer; border-radius: 50%; width: 16px; height: 16px; }
input[type="range"]::-moz-range-thumb { background: rgba(255,255,255,0.8); cursor: pointer; border-radius: 50%; width: 16px; height: 16px; border: none; }

.save-btn {
    width: 100%;
    margin-top: 0.75rem;
    padding: 0.65rem 1.25rem;
    font-size: 0.85rem;
    font-weight: 600;
    border-radius: var(--radius-sm) !important;
    background: linear-gradient(135deg, #333333, #525252) !important;
    border: none !important;
    color: var(--color-text-full) !important;
    box-shadow: 0 8px 25px rgb(0,0,0), 0 0 30px rgb(0,0,0) !important;
    cursor: pointer;
    transition: transform 0.4s ease, box-shadow 0.4s ease !important;
}

.save-btn:hover { background: rgba(255,255,255,0.15) !important; }
.save-btn:active { transform: translateY(1px) scale(0.98) !important; }

.save-btn-danger {
    background: rgba(239, 68, 68, 0.2) !important;
    border: 1px solid rgba(239, 68, 68, 0.3) !important;
    color: rgba(239, 68, 68, 0.9) !important;
}
.save-btn-danger:hover { background: rgba(239, 68, 68, 0.3) !important; border-color: rgba(239, 68, 68, 0.4) !important; }

.theme-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 8px; margin-top: 1rem; }

.theme-option {
    padding: 0.75rem 1rem;
    text-align: center;
    background: rgba(20, 20, 30, 0.4) !important;
    border: 1px solid var(--border-subtle) !important;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 500;
    font-size: 0.9rem;
    color: var(--color-text-muted);
    transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
    box-shadow: none !important;
    contain: layout style paint;
}

.theme-option:hover { background: var(--color-surface-hover) !important; border-color: rgba(255,255,255,0.15) !important; color: var(--color-text-full); }
.theme-option.active { border-color: var(--border-strong) !important; background: rgba(255,255,255,0.12) !important; color: rgba(255,255,255,1); }
.theme-option:focus-visible { outline: 3px solid var(--color-accent-main); outline-offset: 4px; }

/* ── Theme variables ── */
[data-theme="dark"]       { --color-primary-bg:#000000; --color-secondary-bg:#000000; --color-accent-main:#ffffff; --color-accent-hover:#ffffff; --color-text:#ffffff; --color-text-muted:#ffffff; --color-border:#ffffff; }
[data-theme="light"]      { --color-primary-bg:#f5f5f0; --color-secondary-bg:#ffffff; --color-accent-main:#6366f1; --color-accent-hover:#4f46e5; --color-text:#111827; --color-text-muted:#6b7280; --color-border:#e5e7eb; }
[data-theme="matrix"]     { --color-primary-bg:#050c05; --color-secondary-bg:#0a160a; --color-accent-main:#00e536; --color-accent-hover:#00ff41; --color-text:#ccf2d0; --color-text-muted:#4a9e58; --color-border:#0d2e0d; }
[data-theme="blood"]      { --color-primary-bg:#160404; --color-secondary-bg:#220808; --color-accent-main:#e03535; --color-accent-hover:#ff4444; --color-text:#f5e0e0; --color-text-muted:#9e6e6e; --color-border:#3d0f0f; }
[data-theme="sunset"]     { --color-primary-bg:#16091e; --color-secondary-bg:#211030; --color-accent-main:#f97316; --color-accent-hover:#fb923c; --color-text:#fef3e2; --color-text-muted:#b89ec4; --color-border:#3a1f52; }
[data-theme="forest"]     { --color-primary-bg:#080f09; --color-secondary-bg:#111c12; --color-accent-main:#4ade80; --color-accent-hover:#22c55e; --color-text:#ecfdf5; --color-text-muted:#6ea87a; --color-border:#1a3320; }
[data-theme="cyberpunk"]  { --color-primary-bg:#090909; --color-secondary-bg:#141414; --color-accent-main:#00e5ff; --color-accent-hover:#40cfff; --color-text:#f0feff; --color-text-muted:#4db8c8; --color-border:#0e5ff3; }
[data-theme="midnight"]   { --color-primary-bg:#080c14; --color-secondary-bg:#111827; --color-accent-main:#3b82f6; --color-accent-hover:#60a5fa; --color-text:#f1f5f9; --color-text-muted:#94a3b8; --color-border:#1e2d45; }
[data-theme="purplehaze"] { --color-primary-bg:#0e0818; --color-secondary-bg:#170d26; --color-accent-main:#a855f7; --color-accent-hover:#c084fc; --color-text:#f3e8ff; --color-text-muted:#9d7ab8; --color-border:#2e1653; }
[data-theme="coffee"]     { --color-primary-bg:#120e0b; --color-secondary-bg:#1e1712; --color-accent-main:#c8965a; --color-accent-hover:#e0b87a; --color-text:#fdf8ed; --color-text-muted:#a08060; --color-border:#362518; }
[data-theme="ocean"]      { --color-primary-bg:#060e18; --color-secondary-bg:#0c1a2e; --color-accent-main:#0ea5e9; --color-accent-hover:#38bdf8; --color-text:#e0f2fe; --color-text-muted:#6b90af; --color-border:#162d4a; }

/* ── Scrollbars ── */
#lessons-view,
#s-view,
#lesson-box-wrapper,
body {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

#lessons-view::-webkit-scrollbar,
#s-view::-webkit-scrollbar,
#lesson-box-wrapper::-webkit-scrollbar,
body::-webkit-scrollbar {
    display: none;
    width: 0;
    height: 0;
}

/* ── Reduced motion ── */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}

/* ── Page animations ── */
#home-page-view, #lessons-view, #s-view {
    animation: fadeIn 0.5s ease-out forwards;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to   { opacity: 1; transform: translateY(0); }
}

html:not(.loaded) #home-page-view { opacity: 0; transform: translateY(30px); }
html.loaded #home-page-view { opacity: 1; transform: translateY(0); transition: opacity 0.8s ease, transform 0.8s ease; }

/* ── Loader ── */
#lesson-loader {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background-color: var(--color-primary-bg);
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1001;
    color: var(--color-text);
    font-size: 1.2rem;
    gap: 1rem;
}

#lesson-loader.active { display: flex; }

.spinner {
    width: 50px; height: 50px;
    border: 5px solid var(--color-border);
    border-top-color: var(--color-accent-main);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* ── Home view ── */
#home-page-view {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    padding: 1.5rem;
    gap: 2rem;
    position: relative;
}

.home-left { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 1rem; }
.home-right { flex: 1; display: flex; justify-content: center; }

.typewriter-container { font-size: 2.2rem; font-weight: 600; line-height: 1.3; text-align: center; max-width: 90%; }
.static-text { color: var(--color-text); }
.accent-word { color: var(--color-accent-main); font-weight: 700; display: inline-block; }

.play-btn, .about-blank-btn {
    background: linear-gradient(135deg, #333333, #525252) !important;
    color: white;
    font-weight: 600;
    border-radius: var(--radius-sm) !important;
    border: none !important;
    box-shadow: 0 8px 25px rgb(0,0,0), 0 0 30px rgb(0,0,0) !important;
    transition: transform 0.4s ease, box-shadow 0.4s ease !important;
}

.play-btn { padding: 1rem 2.5rem; font-size: 1.4rem; }

#home-page-view .about-blank-btn {
    padding: 0.6rem 1.2rem !important;
    font-size: 0.85rem !important;
    position: absolute;
    bottom: 1rem;
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-surface-hover) !important;
    color: var(--color-text-muted) !important;
    border: 1px solid var(--border-subtle) !important;
    box-shadow: none !important;
    font-weight: 500;
}

#home-page-view .about-blank-btn:hover { background: rgba(255,255,255,0.12) !important; color: var(--color-text-full) !important; border-color: rgba(255,255,255,0.15) !important; }

.play-btn:active, .about-blank-btn:active { transform: translateY(1px) scale(0.98) !important; }
.play-btn:focus-visible, .about-blank-btn:focus-visible { outline: 2px solid var(--color-accent-main); outline-offset: 2px; }

/* Shared button interactions */
.play-btn, .about-blank-btn, .save-btn, .theme-option, .tab-button {
    cursor: pointer;
    transform: translateY(0) scale(1) translateZ(0);
}

.play-btn:active, .about-blank-btn:active, .save-btn:active,
.theme-option:active, .tab-button:active {
    transform: translateY(2px) scale(0.98) translateZ(0) !important;
    transition: transform 0.1s ease !important;
}

/* ── Showcase ── */
.showcase-lesson {
    width: 100%;
    max-width: 280px;
    background: rgba(20, 20, 30, 0.4) !important;
    border: 1px solid var(--border-subtle) !important;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: none !important;
    text-align: center;
    display: flex;
    flex-direction: column;
    transition: transform 0.3s, box-shadow 0.3s;
}

.showcase-lesson img { width: 100%; height: 100%; max-height: 200px; object-fit: cover; }

.showcase-lesson::after {
    content: '';
    display: block;
    height: 1px;
    background-color: var(--color-accent-main);
    margin: 0 0.75rem;
}

.showcase-title {
    padding: 0.8rem;
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--color-text);
    margin-top: auto;
    text-shadow: 0 2px 10px rgba(0,0,0,0.5), 0 0 15px rgba(0,0,0,0.4);
}

h1.gradient-word, .s-category h2 {
    text-shadow: 0 2px 10px rgba(0,0,0,0.5), 0 0 15px rgba(0,0,0,0.4);
}

/* ── Search ── */
.search-container {
    position: sticky;
    top: 0;
    z-index: 10;
    width: 100%;
    max-width: 780px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    gap: 12px;
    align-items: center;
    justify-content: center;
    box-sizing: border-box;
}

.search-wrapper { flex: 1; position: relative; max-width: 400px; display: flex; align-items: center; width: 100%; }

#lesson-search {
    width: 100%;
    padding: 10px 16px 10px 40px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-default) !important;
    border-top: 1px solid var(--border-subtle) !important;
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(24px) saturate(180%);
    -webkit-backdrop-filter: blur(24px) saturate(180%);
    color: var(--color-text-full);
    font-size: 0.9rem;
    outline: none;
    line-height: 1.5;
    box-sizing: border-box;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
    transform: translateZ(0);
    transition: background-color 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                border-color 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

#lesson-search::placeholder { color: var(--color-text-muted); }

#lesson-search:focus {
    background: rgba(255,255,255,0.03);
    border-color: var(--border-strong) !important;
    border-top-color: rgba(255,255,255,0.20) !important;
    box-shadow: 0 8px 24px rgba(0,0,0,0.3);
}

.search-icon {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text-muted);
    width: 18px; height: 18px;
    stroke-width: 2;
    pointer-events: none;
    z-index: 1;
    display: flex;
    align-items: center;
}

/* ── Dropdowns ── */
.category-wrapper, .provider-wrapper { position: relative; }

.category-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    padding: 0.75rem 1rem;
    min-width: 140px;
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--border-default);
    border-top: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    color: var(--color-text-full);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                border-color 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
    transform: translateZ(0);
}

.category-toggle:hover { background: rgba(255,255,255,0.03); border-color: var(--border-strong); box-shadow: 0 8px 24px rgba(0,0,0,0.3); }
.category-toggle .dropdown-arrow { transition: transform 0.3s ease; color: var(--color-text-muted); }
.category-toggle.active .dropdown-arrow, .dropdown-arrow.rotate-180 { transform: rotate(180deg); }

.category-menu {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    min-width: 200px;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(30px) saturate(200%);
    -webkit-backdrop-filter: blur(30px) saturate(200%);
    border: 1px solid var(--border-default);
    border-top: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    padding: 8px;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
    z-index: 100;
    overflow: hidden;
}

.category-menu.hidden { display: none; }

.category-option {
    display: flex;
    align-items: center;
    gap: 10px;
    width: 100%;
    padding: 0.75rem 1rem;
    background: transparent;
    border: none;
    border-radius: 8px;
    color: var(--color-text-full);
    font-size: 0.875rem;
    text-align: left;
    cursor: pointer;
    transition: background-color 0.2s ease, color 0.2s ease;
    font-weight: 500;
}

.category-option:hover { background: var(--color-surface-hover); color: rgba(255,255,255,1); }
.category-option svg { flex-shrink: 0; color: var(--color-text-muted); }
.category-option:hover svg { color: rgba(255,255,255,1); }
.category-divider { height: 1px; background: var(--border-subtle); margin: 6px 0; }

.provider-wrapper .category-toggle { min-width: 120px; }
.provider-wrapper .category-menu { min-width: 160px; }

/* ── Particle canvas ── */
#particle-canvas {
    position: fixed;
    top: 0; left: 0;
    width: 100vw; height: 100vh;
    z-index: 9999;
    opacity: 0.6;
    will-change: transform; /* justified — animates every frame */
    transform: translateZ(0);
    pointer-events: none;
}

/* ── Sidebar nav buttons ── */
.sidebar-btn, .nav-button, #sidebar button {
    width: 44px; height: 44px;
    background: transparent !important;
    color: var(--color-text-muted) !important;
    border: none !important;
    box-shadow: none !important;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: background-color 0.2s ease, color 0.2s ease;
    padding: 0;
    outline: none;
}

.sidebar-btn svg, .nav-button svg { width: 22px; height: 22px; stroke-width: 2; }
.sidebar-btn:hover, .nav-button:hover, #sidebar button:hover { background: var(--color-surface-hover) !important; color: var(--color-text-full) !important; }
.sidebar-btn.active, .nav-button.active { background: rgba(255,255,255,0.15) !important; color: rgba(255,255,255,1) !important; }
.sidebar-btn::before, .sidebar-btn::after, .nav-button::before, .nav-button::after { display: none !important; }

#home-about-blank-btn, #sidebar .about-blank-btn {
    width: auto;
    min-width: 100px;
    padding: 0.5rem 0.75rem !important;
    font-size: 0.7rem !important;
    background: var(--color-surface-hover) !important;
    color: var(--color-text-muted) !important;
    border: 1px solid var(--border-subtle) !important;
    border-radius: var(--radius-sm) !important;
    box-shadow: none !important;
    transition: all 0.2s ease;
    font-weight: 500;
}

#home-about-blank-btn:hover, #sidebar .about-blank-btn:hover { background: rgba(255,255,255,0.12) !important; color: var(--color-text-full) !important; border-color: rgba(255,255,255,0.15) !important; }

/* ── Navbar position variants ── */
body[data-navbar="top"] #sidebar { bottom: auto !important; top: 12px !important; left: 50% !important; right: auto !important; transform: translateX(-50%) !important; flex-direction: row !important; }
body[data-navbar="top"] #sidebar nav ul { flex-direction: row !important; }
body[data-navbar="left"] #sidebar { bottom: auto !important; top: 50% !important; left: 12px !important; right: auto !important; transform: translateY(-50%) !important; flex-direction: column !important; }
body[data-navbar="left"] #sidebar nav ul { flex-direction: column !important; }
body[data-navbar="right"] #sidebar { bottom: auto !important; top: 50% !important; left: auto !important; right: 12px !important; transform: translateY(-50%) !important; flex-direction: column !important; }
body[data-navbar="right"] #sidebar nav ul { flex-direction: column !important; }

@media (max-width: 768px) {
    body[data-navbar="left"] #sidebar,
    body[data-navbar="right"] #sidebar {
        top: auto !important; bottom: 12px !important; left: 50% !important; right: auto !important;
        transform: translateX(-50%) !important; flex-direction: row !important;
    }
    body[data-navbar="left"] #sidebar nav ul,
    body[data-navbar="right"] #sidebar nav ul { flex-direction: row !important; }
}

/* ── Misc UI ── */
#theme-select {
    background-color: rgba(0,0,0,0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    cursor: pointer;
    transition: all 0.3s ease;
    border-color: rgb(0,0,0);
}
#theme-select:hover { border-color: #ffffff; box-shadow: 0 0 20px rgb(0,0,0); background-color: rgb(0,0,0); }
#theme-select:focus { outline: none; border-color: #ffffff; box-shadow: 0 0 25px rgb(0,0,0); }
#theme-select option { background-color: #000000; color: #ffffff; }

.quote-container {
    opacity: 0;
    transform: translateY(40px) scale(0.95) translateZ(0);
    animation: premiumFadeIn 1.2s cubic-bezier(0.25, 0.8, 0.25, 1) forwards;
    animation-delay: 1.2s;
    text-shadow: 0 0 15px rgb(0,0,0);
}

@keyframes premiumFadeIn {
    0%   { opacity: 0; transform: translateY(40px) scale(0.95) translateZ(0); }
    60%  { opacity: 0.7; transform: translateY(10px) scale(1.02) translateZ(0); }
    100% { opacity: 1; transform: translateY(0) scale(1) translateZ(0); }
}

.about-blank-btn { position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%); }

.rounded-full, button.rounded-full, .rounded-full button { border-radius: var(--radius-sm) !important; }

.panic-input { width: 100%; padding: 0.5rem; border: 1px solid var(--color-border); border-radius: 8px; background-color: var(--color-secondary-bg); color: var(--color-text); }

.mini-preview {
    position: absolute;
    bottom: -80px;
    left: 50%;
    transform: translateX(-50%) translateY(20px) translateZ(0);
    width: 180px; height: 100px;
    background: rgb(0,0,0);
    border-radius: 10px;
    border: 1px solid #ffffff;
    opacity: 0;
    transition: all 0.4s ease;
    overflow: hidden;
    box-shadow: 0 10px 30px rgb(0,0,0);
    pointer-events: none;
}

.game-box:hover .mini-preview { opacity: 1; transform: translateY(0) translateZ(0); }
.mini-preview img { width: 100%; height: 100%; object-fit: cover; }

.lazy-game-img { width: 100%; height: 100%; object-fit: cover; display: block; opacity: 0; transition: opacity 0.3s ease; }
.lazy-game-img.loaded { opacity: 1; }

.social-media-tray { display: flex; justify-content: center; gap: 16px; margin-top: 2rem; }

.social-media-icon-container {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px; height: 48px;
    background: linear-gradient(145deg, #000000, #000000);
    border-radius: 16px;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.shiny-btn svg { filter: drop-shadow(0 0 8px rgba(255,255,255,0.5)); transition: filter 0.3s ease; }
.social-media-icon-container:hover svg { filter: drop-shadow(0 0 16px rgba(255,255,255,0.8)); }

.s-card {
    background: rgba(30, 30, 60, 0.4);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid rgba(139, 92, 246, 0.3);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
    transition: all 0.3s ease;
}

.popup-overlay {
    display: flex;
    position: fixed;
    inset: 0;
    background-color: rgba(0,0,0,0.4);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: 10000;
    justify-content: center;
    align-items: center;
}

.popup-content {
    background: transparent;
    backdrop-filter: blur(40px) saturate(180%);
    -webkit-backdrop-filter: blur(40px) saturate(180%);
    color: #ffffff;
    padding: 45px 35px;
    border-radius: 30px;
    position: relative;
    text-align: center;
    max-width: 420px;
    width: 90%;
    border: 1px solid rgba(255,255,255,0.22);
    border-top: 1px solid rgba(255,255,255,0.25);
    box-shadow: 0 40px 100px rgba(0,0,0,0.8);
    animation: slideUp 0.4s ease-out;
}

.popup-content h2 { font-family: 'Inter', sans-serif; font-size: 28px; margin-bottom: 16px; letter-spacing: -0.5px; }
.popup-content p { color: #a1a1a1; font-size: 16px; line-height: 1.6; margin-bottom: 35px; max-width: 340px; margin-inline: auto; }
.popup-content p strong { color: #fff; font-weight: 600; }
.social-links-container { display: flex; flex-direction: column; gap: 14px; }

.social-card {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-surface);
    padding: 16px;
    border-radius: 16px;
    text-decoration: none;
    color: #fff;
    font-weight: 500;
    border: 1px solid var(--border-subtle);
    border-top: 1px solid rgba(255,255,255,0.18);
    transition: background-color 0.2s cubic-bezier(0.4, 0, 0.2, 1),
                border-color 0.2s cubic-bezier(0.4, 0, 0.2, 1),
                transform 0.2s cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 16px rgba(0,0,0,0.3);
    contain: layout style paint;
}

.social-card:hover { background: rgba(255,255,255,0.05); transform: translateY(-2px) translateZ(0); border-color: var(--border-strong); box-shadow: 0 8px 24px rgba(0,0,0,0.4); border-top-color: rgba(255,255,255,0.22); }
.icon-box { margin-right: 12px; display: flex; align-items: center; }

.close-btn { position: absolute; top: 20px; right: 25px; font-size: 32px; cursor: pointer; color: #666; transition: color 0.2s; line-height: 1; }
.close-btn:hover { color: #ff0000; }

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px) scale(0.95) translateZ(0); }
    to   { opacity: 1; transform: translateY(0) scale(1) translateZ(0); }
}

.file-input {
    display: block; width: 100%; font-size: 0.875rem; cursor: pointer;
    padding: 0.5rem;
    background: rgba(147, 51, 234, 0.1);
    border: 1px solid rgba(147, 51, 234, 0.3);
    border-radius: 0.5rem;
    color: #e5e7eb;
    transition: all 0.2s;
}

.file-input:hover { background: rgba(147, 51, 234, 0.2); border-color: rgba(147, 51, 234, 0.5); }

.file-input::file-selector-button {
    margin-right: 1rem; padding: 0.5rem 1rem; border-radius: 0.5rem; border: none;
    font-size: 0.875rem; font-weight: 600; background: #9333ea; color: white; cursor: pointer; transition: background 0.2s;
}

#account-tab input {
    width: 100%; padding: 0.65rem 0.875rem;
    background: rgba(20, 20, 30, 0.5);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    color: var(--color-text-full);
    margin-top: 0.5rem; font-size: 0.875rem;
    box-sizing: border-box; outline: none;
}

.site-footer {
    text-align: center; padding: 2rem 1rem;
    background: rgba(10, 10, 20, 0.6);
    border-top: 1px solid rgba(139, 92, 246, 0.3);
    color: #a0a0ff; font-size: 0.95rem;
}
.site-footer a { color: #ffffff; text-decoration: none; transition: color 0.3s; }
.site-footer a:hover { color: #ffffff; }

.bottom-right-links { position: fixed; bottom: 20px; right: 20px; z-index: 9999; display: flex; flex-direction: row; gap: 15px; align-items: center; }
.bottom-right-link { display: flex; align-items: center; gap: 6px; text-decoration: none; color: #888888; font-size: 13px; font-family: sans-serif; }
.bottom-right-link:hover { color: #555555; }
.bottom-right-link svg { width: 16px; height: 16px; }

/* ── Performance mode ── */
body.perf-mode {
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
}

body.perf-mode * {
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
    animation: none !important;
    transition: none !important;
}

body.perf-mode #particle-canvas { display: none !important; }
body.perf-mode .game-box { box-shadow: none !important; background-color: #1a1a2e !important; transform: none !important; }
body.perf-mode .game-box:hover { border-color: #fff !important; transform: none !important; }
body.perf-mode .showcase-lesson, body.perf-mode .play-btn { box-shadow: 0 4px 10px rgba(0,0,0,0.3) !important; }
body.perf-mode .e-card, body.perf-mode .setting-item, body.perf-mode .tab-button { box-shadow: 0 2px 8px rgba(0,0,0,0.2) !important; }
body.perf-mode #lesson-iframe { box-shadow: none !important; }
body.perf-mode img { image-rendering: pixelated; }
body.perf-mode .game-box:hover, body.perf-mode .e-card:hover, body.perf-mode .setting-item:hover { transform: none !important; box-shadow: inherit !important; }
body.perf-mode #lessons-view { scroll-behavior: auto !important; content-visibility: auto; contain-intrinsic-size: 1000px; }

body.perf-mode #sidebar,
body.perf-mode .category-menu,
body.perf-mode #lesson-search,
body.perf-mode .popup-content,
body.perf-mode .s-card {
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
    background: rgba(10, 10, 10, 0.95) !important;
}

body.perf-mode .setting-item,
body.perf-mode .e-card,
body.perf-mode .category-toggle,
body.perf-mode .social-card,
body.perf-mode #sidebar {
    box-shadow: 0 2px 6px rgba(0,0,0,0.4) !important;
}