.reader-canvas {
    width: 100%;
    height: 100%;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 2rem 0;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    
    /* Dedicated Scrollbar Styling */
    scrollbar-width: thin;
    scrollbar-color: rgba(0, 255, 153, 0.2) transparent;
}

.reader-canvas::-webkit-scrollbar {
    width: 6px;
}

.reader-canvas::-webkit-scrollbar-track {
    background: transparent;
}

.reader-canvas::-webkit-scrollbar-thumb {
    background-color: rgba(0, 255, 153, 0.2);
    border-radius: 20px;
    border: 3px solid transparent;
}

.reader-canvas:hover::-webkit-scrollbar-thumb {
    background-color: rgba(0, 255, 153, 0.5);
}

.reader-canvas.theme-light {
    background-color: #F9F9F9; /* Paper-white requirement */
}

.reader-flow-container {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    position: relative;
    padding: 0 1.5rem 15rem 1.5rem; /* Large padding-bottom for reachability */
}

.block-wrapper {
    transition: all 0.5s ease;
    border-radius: 8px;
    padding: 8px;
    border: 1px solid transparent;
}

/* Typographic refinement for TextSegmentBlock */
::deep .nexus-ebook {
    font-family: 'Merriweather', serif !important;
    line-height: 1.65 !important;
    letter-spacing: -0.01em !important;
    font-size: 1.15rem;
    font-weight: 300;
}

.theme-light ::deep .nexus-ebook {
    color: #1a1a1a;
}

/* Technical Code Block Container */
::deep .nexus-ebook pre {
    background-color: #2d2d2d; /* Dark theme for code for better contrast */
    color: #e0e0e0;
    padding: 1.25rem;
    border-radius: 8px;
    margin: 2rem 0;
    overflow-x: auto;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
    border-left: 4px solid var(--nexus-neon); /* Nexus neon accent */
    
    /* Dedicated Scrollbar for Code */
    scrollbar-width: thin;
    scrollbar-color: rgba(0, 255, 153, 0.3) transparent;
}

::deep .nexus-ebook pre::-webkit-scrollbar {
    height: 4px;
}

::deep .nexus-ebook pre::-webkit-scrollbar-thumb {
    background: rgba(0, 255, 153, 0.3);
    border-radius: 10px;
}

/* Monospace Typography Contrast */
::deep .nexus-ebook code {
    font-family: 'JetBrains Mono', 'Cascadia Code', 'Consolas', monospace !important;
    font-variant-ligatures: contextual;
    line-height: 1.5;
    tab-size: 4;
    font-size: 0.9rem;
}

/* Inline Code Highlight */
::deep .nexus-ebook p code {
    background-color: rgba(0, 0, 0, 0.05);
    color: #d63384; /* Classic differentiator for inline code */
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.9em;
    border: none;
}

.theme-dark ::deep .nexus-ebook p code {
    background-color: rgba(255, 255, 255, 0.1);
    color: #ff79c6;
}

.block-wrapper.highlighted {
    background: rgba(0, 243, 255, 0.08);
    box-shadow: 0 0 20px rgba(0, 243, 255, 0.15);
    border-color: #00f3ff;
    transform: scale(1.01);
}

.ai-sparkle-trigger {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: rgba(18, 18, 18, 0.6);
    border: 1px solid rgba(0, 255, 153, 0.3);
    border-radius: 20px;
    cursor: pointer;
    margin: 1rem 0;
    transition: all 0.3s ease;
    position: relative;
}

.ai-sparkle-trigger:hover {
    background: rgba(0, 255, 153, 0.1);
    border-color: #00ff99;
    transform: translateY(-2px);
}

.sparkle-tooltip {
    font-size: 0.75rem;
    color: #fff;
    opacity: 0.7;
}

.neon-pulse {
    color: #00ff99;
    filter: drop-shadow(0 0 5px #00ff99);
    animation: pulse-small 2s infinite;
}

@keyframes pulse-small {
    0% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.1); opacity: 0.8; }
    100% { transform: scale(1); opacity: 1; }
}

/* Chapter Loading Overlay and Spinners */
.loading-state.full-page {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    min-height: 400px;
    gap: 1.5rem;
    animation: fadeIn 0.4s ease-out;
}

.spinner-glow {
    width: 60px;
    height: 60px;
    border: 3px solid rgba(0, 255, 153, 0.1);
    border-radius: 50%;
    border-top-color: var(--nexus-neon, #00ff99);
    animation: spin 1s cubic-bezier(0.55, 0.055, 0.675, 0.19) infinite;
    box-shadow: 0 0 15px rgba(0, 255, 153, 0.2);
}

.spinner-glow.small {
    width: 36px;
    height: 36px;
    border-width: 2px;
}

.loading-text {
    color: rgba(255, 255, 255, 0.7);
    font-size: 1.1rem;
    letter-spacing: 0.5px;
    font-weight: 500;
}

.theme-light .loading-text {
    color: rgba(0, 0, 0, 0.7);
}

.chapter-loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    background-color: rgba(15, 23, 42, 0.15);
    backdrop-filter: blur(2px);
    animation: fadeIn 0.3s ease-out;
}

.theme-light .chapter-loading-overlay {
    background-color: rgba(255, 255, 255, 0.2);
}

.loader-card {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    padding: 1.25rem 2rem;
    border-radius: 40px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25), 0 0 1px rgba(255, 255, 255, 0.1) inset;
    animation: scaleIn 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.loader-text {
    font-family: var(--nexus-font-sans, 'Inter', sans-serif);
    font-weight: 500;
    color: #ffffff;
    font-size: 0.95rem;
    letter-spacing: 0.2px;
}

.theme-light .loader-text {
    color: #0f172a;
}

.content-blurred {
    filter: blur(3px);
    opacity: 0.55;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    pointer-events: none;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@keyframes scaleIn {
    from { transform: scale(0.9) translateY(10px); opacity: 0; }
    to { transform: scale(1) translateY(0); opacity: 1; }
}

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