/* Ensure inline code is readable in slides */
.inline-code,
.slide-body code,
.slide-content code {
    background: #23272e;
    color: #ffeb95;
    padding: 0.18em 0.38em;
    border-radius: 4px;
    font-family: 'Fira Mono', 'Consolas', 'Menlo', monospace;
    font-size: 1em;
    word-break: break-all;
}

.slide-body pre,
.slide-content pre {
    background: #23272e;
    color: #fff;
    border-radius: 6px;
    padding: 1em;
    overflow-x: auto;
    font-family: 'Fira Mono', 'Consolas', 'Menlo', monospace;
    font-size: 1em;
    margin: 1.2em 0;
}

/* SlidePage.css - Full-page slide presentation styles */



.slide-page {
    position: fixed;
    inset: 0;
    z-index: 1000;
    background: linear-gradient(150deg, #f0f6ff 0%, #eaf8f2 100%);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    color: #1a1a2e;
    --content-text-color: #1a1a2e;
    --content-accent: #149ddd;
}

.slide-page .bullet-label,
.slide-page .content-list-item,
.slide-page .sub-list-item {
    color: #1a1a2e;
}

.topic-exercises-progress {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin: 0 0 1.5rem;
    padding: 1rem 1.1rem;
    background: linear-gradient(135deg, rgba(32, 201, 151, 0.14), rgba(20, 157, 221, 0.12));
    border: 1px solid rgba(15, 23, 42, 0.08);
    border-radius: 14px;
}

.topic-exercises-progress-title {
    margin: 0 0 0.25rem;
    font-size: 1.1rem;
    font-weight: 700;
    color: #0f172a;
}

.topic-exercises-progress-meta {
    margin: 0;
    color: #475569;
    font-size: 0.95rem;
}

.topic-exercises-progress-pill {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 110px;
    padding: 0.5rem 0.8rem;
    border-radius: 999px;
    background: #ffffff;
    color: #0f172a;
    font-weight: 700;
    border: 1px solid rgba(15, 23, 42, 0.1);
}

.topic-exercises-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 1rem;
}

.topic-exercise-card {
    padding: 1rem 1.1rem;
    border: 1px solid #e2e8f0;
    border-radius: 16px;
    background: #fff;
    box-shadow: 0 6px 18px rgba(15, 23, 42, 0.04);
}

.topic-exercise-card-head {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 0.85rem;
}

.topic-exercise-card-title {
    margin: 0 0 0.25rem;
    font-size: 1.22rem;
    line-height: 1.45;
    color: #0f172a;
}

.topic-exercise-card-meta {
    margin: 0;
    color: #64748b;
    font-size: 0.92rem;
}

.topic-exercise-card-body {
    font-size: 1.08rem;
    line-height: 1.8;
    color: #334155;
}

.topic-exercise-card-body p,
.topic-exercise-card-body li {
    font-size: 1em;
    line-height: 1.8;
}

.topic-exercise-check {
    border: none;
    border-radius: 999px;
    padding: 0.35rem 0.65rem;
    font-size: 0.9rem;
    background: #f1f5f9;
    color: #0f172a;
    font-weight: 700;
    cursor: pointer;
    transition: transform 160ms ease, background 160ms ease, color 160ms ease;
}

.topic-exercise-check:hover {
    transform: translateY(-1px);
}

.topic-exercise-check.is-completed {
    background: #10b981;
    color: #fff;
}

.topic-exercise-card-body .content-list {
    margin-bottom: 0;
}

.topic-exercise-card-body h3 {
    font-size: 1.35rem;
    font-weight: 700;
    margin-top: 0.75rem;
    margin-bottom: 0.75rem;
}

.slide-page .inline-code,
.slide-page code {
    background: #f1f5f9;
    color: #b91c1c;
    padding: 0.15em 0.4em;
    border-radius: 4px;
    font-family: 'Fira Mono', 'Consolas', 'Menlo', monospace;
    font-size: 0.93em;
    border: 1px solid #e2e8f0;
}

.slide-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0;
    width: 100%;
    margin: 0;
    padding: 0;
    background: linear-gradient(150deg, #f0f6ff 0%, #eaf8f2 100%);
}

/* Smooth visual transition when content swaps to avoid jitter/layout jumps */
.slide-container.is-transitioning {
    transition: min-height 260ms ease;
}

.slide-content {
    transition: opacity 220ms ease, transform 220ms ease;
}

.slide-container.is-transitioning .slide-content {
    opacity: 0.98;
    transform: translateY(2px);
}

/* Fullscreen mode — applied to .slide-container when browser goes fullscreen */
.slide-container:fullscreen,
.slide-container:-webkit-full-screen,
.slide-container:-moz-full-screen {
    display: flex;
    flex-direction: column;
    width: 100vw;
    height: 100vh;
    background: linear-gradient(150deg, #f0f6ff 0%, #eaf8f2 100%);
    overflow: hidden;
}

/* Fullscreen presentation mode: increase legibility from distance while keeping comfort up close. */
.slide-container:fullscreen .slide-content,
.slide-container:-webkit-full-screen .slide-content,
.slide-container:-moz-full-screen .slide-content {
    max-width: 1220px;
    /* remove top padding in native fullscreen so content sits flush to top */
    padding: 0 clamp(2rem, 2.4vw, 3rem) 1rem;
}

/* Ensure main container has no top padding when element is in native fullscreen
   so embedded notebook/iframe content is not clipped under any header */
.slide-container:fullscreen .slide-main,
.slide-container:-webkit-full-screen .slide-main,
.slide-container:-moz-full-screen .slide-main {
    padding-top: 0;
}

.slide-container:fullscreen .slide-title,
.slide-container:-webkit-full-screen .slide-title,
.slide-container:-moz-full-screen .slide-title {
    font-size: clamp(1.87rem, 2.30vw, 2.88rem);
    line-height: 1.08;
    margin-bottom: 1.4rem;
}

.slide-container:fullscreen .slide-body,
.slide-container:-webkit-full-screen .slide-body,
.slide-container:-moz-full-screen .slide-body {
    font-size: clamp(1.04rem, 0.97rem + 0.50vw, 1.40rem);
    line-height: 1;
}

/* Forceful overrides for fullscreen/presentation to avoid tiny rem rounding gaps */
.slide-container:fullscreen .slide-main,
.slide-container:-webkit-full-screen .slide-main,
.slide-container:-moz-full-screen .slide-main,
.slide-container.is-presentation-fullscreen .slide-main {
    padding: 0 !important;
    margin: 0 !important;
}

.slide-container:fullscreen .slide-content,
.slide-container:-webkit-full-screen .slide-content,
.slide-container:-moz-full-screen .slide-content,
.slide-container.is-presentation-fullscreen .slide-content {
    margin: 0 !important;
    padding: 0 !important;
    border-radius: 0 !important;
    border-top: none !important;
}

/* Show a subtle top divider in fullscreen/presentation without adding layout space. */
.slide-container:fullscreen .slide-content,
.slide-container:-webkit-full-screen .slide-content,
.slide-container:-moz-full-screen .slide-content,
.slide-container.is-presentation-fullscreen .slide-content {
    box-shadow: inset 0 1px 0 rgba(0, 0, 0, 0.06) !important;
    position: relative !important;
    z-index: 1 !important;
}

/* Strong fallback: render a real top divider using a pseudo-element so it's
   always visible inside fullscreen/presentation, and does not affect layout. */
.slide-container:fullscreen .slide-content::before,
.slide-container:-webkit-full-screen .slide-content::before,
.slide-container:-moz-full-screen .slide-content::before,
.slide-container.is-presentation-fullscreen .slide-content::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    /* match original border-top thickness */
    background: linear-gradient(90deg, #20c997, rgba(32, 201, 151, 0.85));
    pointer-events: none;
    z-index: 3 !important;
}

/* Zero padding for list items in fullscreen to avoid truncation of notebook header */
.slide-container:fullscreen li.content-list-item,
.slide-container:-webkit-full-screen li.content-list-item,
.slide-container:-moz-full-screen li.content-list-item,
.slide-container.is-presentation-fullscreen li.content-list-item {
    padding-top: 0 !important;
    padding-bottom: 0 !important;
    padding-left: 0 !important;
    padding-right: 0 !important;
    margin-top: 0 !important;
    margin-bottom: 0.5em !important;
}

.slide-container:fullscreen .slide-body p,
.slide-container:fullscreen .slide-body li,
.slide-container:-webkit-full-screen .slide-body p,
.slide-container:-webkit-full-screen .slide-body li,
.slide-container:-moz-full-screen .slide-body p,
.slide-container:-moz-full-screen .slide-body li {
    margin-bottom: 0.75rem;
}

.slide-container:fullscreen .slide-body ul,
.slide-container:fullscreen .slide-body ol,
.slide-container:-webkit-full-screen .slide-body ul,
.slide-container:-webkit-full-screen .slide-body ol,
.slide-container:-moz-full-screen .slide-body ul,
.slide-container:-moz-full-screen .slide-body ol {
    padding-left: 1.75rem;
}

.slide-container:fullscreen .slide-counter,
.slide-container:-webkit-full-screen .slide-counter,
.slide-container:-moz-full-screen .slide-counter {
    font-size: 0.78rem;
}

.slide-container:fullscreen .slide-counter-label,
.slide-container:-webkit-full-screen .slide-counter-label,
.slide-container:-moz-full-screen .slide-counter-label {
    font-size: 0.61rem;
}

/* Explicit class fallback/booster for fullscreen readability across all content blocks. */
.slide-container.is-presentation-fullscreen .slide-content {
    max-width: 100%;
    padding: 0;
    grid-template-columns: 1fr auto;
    grid-template-rows: auto auto;
    grid-template-areas:
        "title controls"
        "body body";
}

.slide-container.is-presentation-fullscreen .slide-controls-top-right {
    padding: clamp(0.75rem, 1vw, 1rem) clamp(2rem, 2.7vw, 3.15rem) 0 1rem;
    grid-area: controls;
    align-self: start;
}

.slide-container.is-presentation-fullscreen .slide-title {
    font-size: clamp(2.52rem, 2.74vw, 3.24rem) !important;
    line-height: 1.08;
    margin-bottom: 0.9rem;
    padding: 0 1rem 0.7rem clamp(2rem, 2.7vw, 3.15rem);
    border-bottom: 2px solid #e5e7eb;
    grid-area: title;
}

.slide-container.is-presentation-fullscreen .slide-body,
.slide-container.is-presentation-fullscreen .slide-body p,
.slide-container.is-presentation-fullscreen .slide-body li,
.slide-container.is-presentation-fullscreen .content-list-item,
.slide-container.is-presentation-fullscreen .sub-list-item,
.slide-container.is-presentation-fullscreen .bullet-label {
    font-size: clamp(1.8rem, 0.95rem + 0.61vw, 1.44rem) !important;
    /* Slightly tighter line-height for lists to remove excessive vertical gaps */
    line-height: 1.28 !important;
    /* Reduce bottom padding so list items sit closer together on tall layouts */
}

/* Ensure list items themselves don't retain large margins inside presentation mode */
.slide-container.is-presentation-fullscreen .slide-body p,
.slide-container.is-presentation-fullscreen .slide-body li,
.slide-container.is-presentation-fullscreen .content-list-item {
    margin-bottom: 0.5rem !important;
    line-height: 1.5 !important;
}

.slide-container.is-presentation-fullscreen .slide-body {
    grid-area: body;
}

.slide-container.is-presentation-fullscreen .slide-body ul,
.slide-container.is-presentation-fullscreen .slide-body ol {
    padding-left: 1.85rem;
}

.slide-container.is-presentation-fullscreen .slide-body code,
.slide-container.is-presentation-fullscreen .slide-content code,
.slide-container.is-presentation-fullscreen .slide-body pre,
.slide-container.is-presentation-fullscreen .slide-content pre {
    font-size: 1.05em;
}

.slide-container.is-presentation-fullscreen .content-table,
.slide-container.is-presentation-fullscreen .content-table table,
.slide-container.is-presentation-fullscreen .content-table th,
.slide-container.is-presentation-fullscreen .content-table td,
.slide-container.is-presentation-fullscreen .table-title,
.slide-container.is-presentation-fullscreen .table-caption {
    font-size: clamp(0.85rem, 0.78rem + 0.29vw, 1.08rem) !important;
}

.slide-container.is-presentation-fullscreen .slide-counter {
    font-size: 0.81rem;
}

/* Header */
.slide-header {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    padding: 0.5rem 1rem;
    background: transparent;
    margin-bottom: 0;
    flex-shrink: 0;
    border-bottom: none;
    box-shadow: none;
    min-height: 2rem;
}

.slide-main {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    overscroll-behavior-y: contain;
    padding: 0.05rem 0.5rem 0.25rem 0.5rem;
}

.slide-content {
    padding: 0;
    margin: 0 auto;
    max-width: 960px;
    width: 100%;
    word-break: break-word;
    background: #fff;
    border-radius: 14px;
    border-top: 4px solid #20c997;
    box-shadow: 0 2px 8px rgba(15, 23, 42, 0.06), 0 12px 40px rgba(15, 23, 42, 0.09);
    position: relative;
    display: grid;
    grid-template-columns: 1fr auto;
    grid-template-rows: auto auto;
    grid-template-areas:
        "title controls"
        "body body";
}

.slide-controls-top-right {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 0.75rem;
    padding: 1rem 1.5rem 0 1rem;
    flex-shrink: 0;
    grid-area: controls;
    align-self: start;
}

.slide-title {
    grid-area: title;
}

.slide-body {
    grid-area: body;
}

.slide-controls-top-right .slide-counter {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.9rem;
    color: #64748b;
    margin-right: 0.5rem;
}

.slide-counter-label {
    font-weight: 500;
    color: #475569;
}

.slide-counter-current {
    color: #1a1a2e;
    font-weight: 600;
}

.slide-counter-divider {
    color: #cbd5e1;
}

.slide-counter-total {
    color: #64748b;
}

.slide-nav-btn {
    background: transparent;
    border: 1px solid #d1d5db;
    padding: 0.4rem 0.5rem;
    border-radius: 6px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #374151;
    font-size: 1.1rem;
    transition: all 0.2s ease;
}

.slide-nav-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.slide-nav-btn:not(:disabled):hover {
    background: #f3f4f6;
    border-color: #9ca3af;
    transform: translateY(-1px);
}

.exit-btn {
    background: transparent;
    border: 1px solid #d1d5db;
    padding: 0.4rem 0.6rem;
    border-radius: 6px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #374151;
    font-size: 1.1rem;
    text-decoration: none;
    transition: all 0.2s ease;
}

.exit-btn:hover {
    background: #fecaca;
    border-color: #f87171;
    color: #991b1b;
}

.slide-container.is-presentation-fullscreen .slide-header,
.slide-container:fullscreen .slide-header,
.slide-container:-webkit-full-screen .slide-header,
.slide-container:-moz-full-screen .slide-header {
    /* Hide the page header in presentation/native fullscreen so content
       starts at the very top of the viewport (no clipped notebook header). */
    display: none !important;
    visibility: hidden !important;
    height: 0 !important;
    margin: 0 !important;
    padding: 0 !important;
    background: transparent !important;
    border: none !important;
}

.slide-container.is-presentation-fullscreen .slide-main,
.slide-container:fullscreen .slide-main,
.slide-container:-webkit-full-screen .slide-main,
.slide-container:-moz-full-screen .slide-main {
    padding-top: 0;
}

.slide-container.is-presentation-fullscreen .slide-content {
    margin: 0;
    padding: 0;
    max-width: 100%;
    width: 100%;
    border-top-left-radius: 0;
    border-top-right-radius: 0;
    border-top: none;
    grid-template-columns: 1fr auto;
    grid-template-rows: auto auto;
    grid-template-areas:
        "title controls"
        "body body";
}

.slide-container.is-presentation-fullscreen .slide-controls-top-right {
    padding: clamp(0.75rem, 1vw, 1rem) clamp(2rem, 2.7vw, 3.15rem) 0 1rem;
    grid-area: controls;
    align-self: start;
}

.slide-container.is-presentation-fullscreen .slide-title {
    padding: 0 1rem 0 clamp(2rem, 2.7vw, 3.15rem);
    grid-area: title;
}

.slide-container.is-presentation-fullscreen .slide-body {
    padding: 0 clamp(2rem, 2.7vw, 3.15rem) 1rem clamp(2rem, 2.7vw, 3.15rem);
    grid-area: body;
}

.presentation-toolbar {
    display: none;
}

.slide-container.is-presentation-fullscreen .presentation-toolbar,
.slide-container:fullscreen .presentation-toolbar {
    display: flex;
    position: absolute;
    top: 10px;
    right: 12px;
    gap: 0.5rem;
    z-index: 60;
    align-items: center;
}

.presentation-btn {
    background: rgba(255, 255, 255, 0.96);
    border: 1px solid rgba(15, 23, 42, 0.06);
    padding: 0.42rem 0.6rem;
    border-radius: 8px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #0f172a;
    font-size: 1.05rem;
    box-shadow: 0 4px 10px rgba(2, 6, 23, 0.08);
}

.presentation-btn:disabled {
    opacity: 0.45;
    cursor: default;
}

.presentation-btn:hover:not(:disabled) {
    transform: translateY(-1px);
}

.presentation-btn.fullscreen {
    background: rgba(32, 201, 151, 0.96);
    color: #fff;
}



.slide-title {
    font-size: clamp(2rem, 1.4rem + 2vw, 3rem);
    line-height: 1.1;
    margin-bottom: 1rem;
    padding: 0.8rem 1rem 0.75rem 1rem;
    color: #0f172a;
    font-weight: 700;
    text-shadow: none;
    border-left: 4px solid #20c997;
    border-bottom: 2px solid #e5e7eb;
    align-self: start;
}

.slide-body {
    padding: 0 2.5rem 0.5rem 1rem;
}

.slide-page .slide-body,
.exercise-page .slide-body {
    font-size: 1.22rem;
    line-height: 1.85;
    color: #374151;
}

.slide-page .slide-title,
.exercise-page .slide-title {
    font-size: clamp(2.2rem, 3vw, 3rem);
    line-height: 1.08;
}


.slide-body p,
.slide-body li {
    margin-bottom: 1rem;
}

/* Indent direct child headings in slide body to match list text alignment */
.slide-body>h1,
.slide-body>h2,
.slide-body>h3,
.slide-body>h4,
.slide-body>h5,
.slide-body>h6 {
    margin-left: 1.5rem;
    margin-top: 0.6rem;
    margin-bottom: 0.4rem;
}

/* If content uses a leading bold paragraph (e.g. <p><strong>Heading</strong></p>),
   render the strong as a block and indent it so it lines up with bullets. */
.slide-body p>strong:first-child,
.slide-body p>b:first-child {
    display: block;
    margin-left: 1.5rem;
    margin-bottom: 0.4rem;
    line-height: 1.2;
    font-weight: 700;
}



.slide-body ul,
.slide-body ol {
    padding-left: 1.5rem;
    margin: 1rem 0;
    color: #374151;
    background: transparent;
    list-style-type: disc;
}

.slide-body li::marker {
    color: #20c997;
}

.slide-body ul ul,
.slide-body ol ul,
.slide-body ul ol,
.slide-body ol ol {
    color: #6b7280;
    background: transparent;
    list-style-type: circle;
}


.slide-main::-webkit-scrollbar {
    width: 8px;
}

.slide-main::-webkit-scrollbar-track {
    background: transparent;
}

.slide-main::-webkit-scrollbar-thumb {
    background: #c8d5e0;
    border-radius: 999px;
}

.slide-main::-webkit-scrollbar-thumb:hover {
    background: #a0b3c0;
}

.slide-breadcrumb {
    display: none;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: #64748b;
}

.slide-page .slide-breadcrumb {
    display: flex;
}

.slide-breadcrumb a {
    color: #20c997;
    text-decoration: none;
    transition: color 0.2s;
}

.slide-breadcrumb a:hover {
    color: #15805e;
}

.slide-breadcrumb span {
    color: #94a3b8;
}

.slide-header-right {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.mobile-header-icons {
    display: none;
    align-items: center;
    gap: 0.35rem;
}

.exercise-header-left {
    display: flex;
    align-items: flex-start;
    flex-direction: column;
    gap: 0.35rem;
    min-width: 0;
}

.exercise-header-right {
    display: none;
}

.exercise-header-left {
    display: none;
}

@media (min-width: 769px) {
    .exercise-page .exercise-header-left {
        flex: 1 1 auto;
        align-items: flex-start;
    }

    .exercise-page .exercise-header-right {
        flex-shrink: 0;
    }
}

.slide-counter {
    color: #155e34;
    font-size: 0.86rem;
    padding: 0.28rem 0.6rem;
    background: #eafaf1;
    border-radius: 999px;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}

.slide-counter-label {
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #0f5132;
}

.slide-counter-current,
.slide-counter-total {
    font-weight: 700;
    font-size: 0.88rem;
    color: #0b3d2e;
}

.slide-counter-divider {
    color: #4b5563;
    font-weight: 700;
    opacity: 0.9;
}

.exit-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: #fee2e2;
    border: 1px solid #fecaca;
    border-radius: 50%;
    color: #991b1b;
    font-size: 1.25rem;
    font-weight: 700;
    line-height: 1;
    text-decoration: none;
    transition: background 160ms ease, transform 120ms ease;
}

.exit-btn:hover {
    background: #fecaca;
    color: #7f1d1d;
    transform: scale(1.03);
}

.slide-nav-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    background: #fff;
    border: 1px solid #d1dbe8;
    border-radius: 50%;
    color: #1f2937;
    font-size: 1.05rem;
    cursor: pointer;
    transition: all 0.2s;
    padding: 0;
}

.slide-nav-btn:hover:not(:disabled) {
    background: #d5f7e5;
    border-color: #20c997;
    transform: scale(1.08);
}

.slide-nav-btn:disabled {
    opacity: 0.35;
    cursor: default;
}

/* ── Progress bar footer ── */
.slide-footer {
    flex-shrink: 0;
    height: 4px;
    background: rgba(15, 23, 42, 0.08);
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    width: 100%;
}

.progress-fill {
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, #20c997 0%, #3b82f6 100%);
    transform-origin: left center;
    transition: transform 0.45s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 0 999px 999px 0;
}

/* Accessible helper: visually hidden but available to screen readers */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
    white-space: nowrap;
    border: 0;
}

.exercise-completion-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.45rem 0.75rem;
    border-radius: 999px;
    border: 1px solid #d1dbe8;
    background: #f3f5f8;
    color: #334155;
    font-size: 0.82rem;
    font-weight: 700;
    line-height: 1;
    cursor: pointer;
    transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.exercise-completion-toggle:hover {
    background: #eaf0f5;
    border-color: #c8d2dc;
    color: #0f172a;
    transform: translateY(-1px);
}

.exercise-completion-toggle i {
    font-size: 0.98rem;
}

.exercise-completion-toggle.is-completed {
    background: #e9f9f0;
    border-color: #9be1b5;
    color: #166534;
}

.exercise-page .exercise-completion-toggle {
    width: auto;
    height: auto;
    padding: 0.28rem 0.6rem;
    border-radius: 999px;
    justify-content: center;
    gap: 0.35rem;
    min-height: 34px;
}

.exercise-page .exercise-completion-toggle .exercise-completion-icon {
    font-size: 1rem;
    font-family: inherit;
    font-weight: 700;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    line-height: 1;
}

.exercise-page .exercise-completion-toggle .completion-label {
    display: inline-block;
    margin-left: 0;
    font-weight: 700;
    color: inherit;
}

.slide-content.exercise-content.is-completed {
    border-top-color: #16a34a;
}

.slide-content.exercise-content.is-completed .slide-title {
    border-left-color: #16a34a;
}

/* Annotation toolbar (must stay above canvas) */
.annotation-toolbar {
    position: absolute;
    top: 1rem;
    right: 1rem;
    z-index: 30;
    display: flex;
    align-items: center;
    gap: 0.45rem;
    flex-wrap: wrap;
    max-width: min(92%, 760px);
    padding: 0.55rem;
    border: 1px solid #d1dbe8;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 0 8px 22px rgba(15, 23, 42, 0.14);
}

.annotation-toolbar-close,
.annotation-toolbar-drag,
.annotation-tool-btn {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    border: 1px solid #d1dbe8;
    background: #fff;
    color: #1f2937;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    padding: 0;
    transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.annotation-toolbar-close:hover,
.annotation-toolbar-drag:hover,
.annotation-tool-btn:hover {
    background: #f0f9ff;
    border-color: #7dd3fc;
    color: #0c4a6e;
}

.annotation-tool-btn.active {
    background: #d5f7e5;
    border-color: #20c997;
    color: #0f5c3f;
    box-shadow: inset 0 0 0 1px rgba(32, 201, 151, 0.2);
}

.annotation-tool-btn:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.annotation-color-wrap,
.annotation-size-wrap {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0 0.2rem;
}

.annotation-color-input {
    width: 32px;
    height: 32px;
    border: 1px solid #d1dbe8;
    border-radius: 8px;
    background: #fff;
    cursor: pointer;
    padding: 2px;
}

.annotation-size-label {
    font-size: 0.78rem;
    color: #4b5563;
    font-weight: 600;
}

.annotation-size-input {
    width: 88px;
}

.annotation-textarea {
    width: 100%;
    min-height: 60px;
    border: 1px solid #d1dbe8;
    border-radius: 6px;
    padding: 0.4rem 0.5rem;
    font-size: 0.95rem;
    resize: vertical;
    outline: none;
}

.annotation-textarea:focus {
    border-color: #20c997;
}

.annotation-text-editor-actions {
    display: flex;
    gap: 0.4rem;
    margin-top: 0.4rem;
    justify-content: flex-end;
}

.annotation-text-editor-actions button {
    padding: 0.25rem 0.65rem;
    border-radius: 5px;
    border: 1px solid #20c997;
    background: #20c997;
    color: #fff;
    font-size: 0.85rem;
    cursor: pointer;
}

.annotation-text-editor-actions button:last-child {
    background: #fff;
    color: #374151;
    border-color: #d1dbe8;
}

/* ── Annotation overlays ── */
.annotation-canvas {
    position: absolute;
    inset: 0;
    display: block;
    pointer-events: none;
    z-index: 10;
    border-radius: 12px;
}

.annotation-canvas.active {
    pointer-events: all;
    cursor: crosshair;
}

.annotation-canvas.active.eraser {
    cursor: cell;
}

.annotation-text-note {
    position: absolute;
    z-index: 11;
    pointer-events: none;
    white-space: pre-wrap;
    font-size: 1rem;
    line-height: 1.4;
}

.annotation-text-editor {
    position: absolute;
    z-index: 20;
    background: #fff;
    border: 1px solid #d1dbe8;
    border-radius: 8px;
    padding: 0.5rem;
    box-shadow: 0 4px 16px rgba(15, 23, 42, 0.12);
    min-width: 200px;
}

.annotation-text-input {
    width: 100%;
    min-height: 60px;
    border: 1px solid #d1dbe8;
    border-radius: 6px;
    padding: 0.4rem 0.5rem;
    font-size: 0.95rem;
    resize: vertical;
    outline: none;
}

.annotation-text-input:focus {
    border-color: #20c997;
}

.annotation-text-actions {
    display: flex;
    gap: 0.4rem;
    margin-top: 0.4rem;
    justify-content: flex-end;
}

.annotation-text-btn {
    padding: 0.25rem 0.65rem;
    border-radius: 5px;
    border: 1px solid #20c997;
    background: #20c997;
    color: #fff;
    font-size: 0.85rem;
    cursor: pointer;
}

.annotation-text-btn.secondary {
    background: #fff;
    color: #374151;
    border-color: #d1dbe8;
}

.annotation-cursor-preview {
    position: absolute;
    border-radius: 50%;
    border: 2px solid;
    pointer-events: none;
    z-index: 12;
    transform: translate(-50%, -50%);
    transition: width 0.1s, height 0.1s;
}

@media (max-width: 768px) {
    .slide-page .slide-header {
        padding: 0.5rem 0.6rem;
        gap: 0.35rem;
        justify-content: flex-start;
    }

    .slide-page .slide-breadcrumb {
        display: flex;
    }

    .slide-page .mobile-header-icons {
        display: none;
    }

    .slide-page .slide-header-right {
        display: none;
    }

    .slide-page .slide-main {
        padding: 0.2rem;
    }

    .slide-page .slide-content {
        padding: 0;
        border-radius: 12px;
        grid-template-columns: 1fr auto;
        grid-template-rows: auto auto;
        grid-template-areas:
            "title controls"
            "body body";
    }

    .slide-page .slide-controls-top-right {
        padding: 0.5rem 0.75rem 0 0.75rem;
        gap: 0.5rem;
        font-size: 0.8rem;
        grid-area: controls;
        align-self: start;
    }

    .slide-page .slide-controls-top-right .slide-counter {
        gap: 0.25rem;
        margin-right: 0.3rem;
    }

    .slide-page .slide-counter-label {
        display: none;
    }

    .slide-page .slide-title {
        font-size: clamp(1.55rem, 6.2vw, 2.05rem);
        line-height: 1.14;
        margin-bottom: 1rem;
        padding: 0.5rem 0.75rem 0.62rem 0.72rem;
        border-left-width: 3px;
        grid-area: title;
        align-self: start;
    }

    .slide-page .slide-body {
        font-size: 1.02rem;
        grid-area: body;
        line-height: 1.7;
        padding: 0 0.75rem 0.45rem 0.72rem;
    }

    .slide-page .slide-body p,
    .slide-page .slide-body li {
        margin-bottom: 0.76rem;
    }

    .slide-page .slide-body ul,
    .slide-page .slide-body ol {
        padding-left: 1.2rem;
        margin: 0.75rem 0;
    }

    .exercise-page .slide-header {
        padding: 0.5rem 0.6rem;
        gap: 0.35rem;
        justify-content: flex-start;
    }

    .exercise-page .exercise-header-left {
        display: none;
    }

    .exercise-page .exercise-header-right {
        display: none;
    }

    .exercise-page .slide-controls-top-right {
        padding: 0.5rem 0.75rem 0 0.75rem;
        gap: 0.4rem;
        font-size: 0.75rem;
    }

    .exercise-page .slide-controls-top-right .slide-counter {
        gap: 0.2rem;
        margin-right: 0.2rem;
    }

    .exercise-page .slide-counter-label {
        display: none;
    }

    .exercise-page .exercise-completion-toggle span {
        display: none;
    }
}

@media (max-width: 480px) {
    .slide-page .slide-controls-top-right {
        padding: 0.4rem 0.5rem 0 0.5rem;
        gap: 0.3rem;
        font-size: 0.7rem;
        grid-area: controls;
        align-self: start;
    }

    .slide-page .slide-controls-top-right .slide-counter {
        display: none;
    }

    .slide-page .slide-nav-btn {
        padding: 0.3rem 0.35rem;
        font-size: 0.9rem;
    }

    .slide-page .slide-content {
        grid-template-columns: 1fr auto;
        grid-template-rows: auto auto;
        grid-template-areas:
            "title controls"
            "body body";
    }

    .slide-page .slide-title {
        grid-area: title;
        align-self: start;
    }

    .slide-page .slide-body {
        grid-area: body;
    }

    .exercise-page .slide-controls-top-right {
        padding: 0.4rem 0.5rem 0 0.5rem;
        gap: 0.25rem;
        font-size: 0.65rem;
        grid-area: controls;
        align-self: start;
    }

    .exercise-page .slide-controls-top-right .slide-counter {
        display: none;
    }

    .exercise-page .slide-nav-btn {
        width: 28px;
        height: 28px;
        padding: 0;
        font-size: 0.9rem;
    }

    .exercise-page .slide-content {
        padding: 0;
        border-radius: 12px;
        grid-template-columns: 1fr auto;
        grid-template-rows: auto auto;
        grid-template-areas:
            "title controls"
            "body body";
    }

    .exercise-page .slide-title {
        font-size: clamp(1.45rem, 6vw, 1.95rem);
        margin-bottom: 0.9rem;
        padding: 0.4rem 0.75rem 0.55rem 0.7rem;
        grid-area: title;
        align-self: start;
    }

    .exercise-page .slide-body {
        font-size: 1rem;
        line-height: 1.65;
        padding: 0 0.75rem 0.4rem 0.7rem;
        grid-area: body;
    }

    .exercise-page .slide-body p,
    .exercise-page .slide-body li {
        margin-bottom: 0.72rem;
    }

    .exercise-page .slide-header {
        position: relative;
    }
}