.reader-body {
    background-color: #0f172a;
    color: #e2e8f0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Georgia, serif;
    margin: 0;
    padding: 0;
    -webkit-text-size-adjust: 100%;
}

.reader-controls {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 56px;
    background-color: #1e293b;
    border-bottom: 1px solid #334155;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 0.8rem;
    z-index: 10000;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
    touch-action: manipulation;
    user-select: none;
    -webkit-user-select: none;
}

.btn-icon {
    font-size: 1.3rem;
    text-decoration: none;
    color: #f8fafc;
    padding: 6px 10px;
    border-radius: 6px;
    background-color: rgba(255,255,255,0.05);
}

.book-mini-title {
    font-size: 0.9rem;
    font-weight: 600;
    color: #94a3b8;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 130px;
}

.scroll-toolbar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-play {
    background-color: #38bdf8;
    color: #0f172a;
    border: none;
    padding: 8px 14px;
    border-radius: 8px;
    font-weight: 700;
    cursor: pointer;
    font-size: 0.95rem;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
    transition: background-color 0.2s;
}

.btn-play.active {
    background-color: #ef4444;
    color: #ffffff;
}

.speed-controls {
    display: flex;
    align-items: center;
    background-color: #0f172a;
    border-radius: 8px;
    padding: 3px 6px;
    border: 1px solid #334155;
}

.btn-speed {
    background: none;
    border: none;
    color: #f8fafc;
    font-size: 1.1rem;
    cursor: pointer;
    padding: 4px 8px;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

.btn-speed:active {
    opacity: 0.6;
}

.speed-label {
    font-size: 0.85rem;
    color: #38bdf8;
    font-weight: 700;
    min-width: 60px;
    text-align: center;
}

.progress-badge {
    font-size: 0.9rem;
    font-weight: 700;
    color: #22c55e;
    min-width: 40px;
    text-align: right;
}

.reader-progress-line {
    position: fixed;
    top: 56px;
    left: 0;
    right: 0;
    height: 3px;
    background-color: #334155;
    z-index: 9999;
}

.reader-progress-line .fill {
    height: 100%;
    background-color: #22c55e;
    width: 0%;
    transition: width 0.1s linear;
}

/* HIGH-PERFORMANCE DOM RENDERING VIA CONTENT-VISIBILITY */
.reader-content {
    max-width: 720px;
    margin: 70px auto 50px auto;
    padding: 1rem 1.2rem;
    font-size: 1.25rem;
    line-height: 1.8;
}

.reader-header-info {
    text-align: center;
    margin-bottom: 2rem;
}

.reader-header-info h1 {
    font-size: 2.1rem;
    color: #38bdf8;
    margin-bottom: 0.5rem;
}

.reader-header-info h3 {
    font-size: 1.2rem;
    color: #94a3b8;
}

.divider {
    border: none;
    border-top: 1px solid #334155;
    margin: 1.5rem 0;
}

/* Individual Paragraph Optimization: Skip off-screen rendering for instant loading */
.reader-para {
    content-visibility: auto;
    contain-intrinsic-size: 1px 35px;
    margin-bottom: 1.2rem;
}

.reader-para p {
    margin: 0;
    text-indent: 1.6rem;
    color: #e2e8f0;
}

.reader-para h2 {
    font-size: 1.6rem;
    color: #38bdf8;
    margin: 2rem 0 1rem 0;
    text-align: center;
}

.reader-para h3 {
    font-size: 1.3rem;
    color: #cbd5e1;
    margin: 1.5rem 0 0.8rem 0;
    text-align: center;
}

.empty-line {
    height: 1rem;
}