* {
    box-sizing: border-box;
}

body {
    font-family: system-ui, -apple-system, sans-serif;
    background-color: #1a1a1a;
    color: #e0e0e0;
    margin: 0;
    padding: 0;
}

.reader-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
}

.toolbar {
    position: sticky;
    top: 0;
    background: #2b2b2b;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 16px;
    padding: 12px 20px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
    z-index: 100;
}

.btn {
    background-color: #0078d4;
    color: #ffffff;
    padding: 8px 16px;
    text-decoration: none;
    border-radius: 4px;
    font-weight: 600;
    transition: background 0.2s ease;
}

.btn:hover {
    background-color: #005a9e;
}

.btn.disabled {
    opacity: 0.35;
    pointer-events: none;
}

.page-picker select {
    padding: 6px 12px;
    border-radius: 4px;
    background: #383838;
    color: #ffffff;
    border: 1px solid #555555;
    font-size: 14px;
}

.page-viewport {
    margin: 24px 0;
    display: flex;
    justify-content: center;
    width: 100%;
}

.book-page {
    max-width: 92vw;
    max-height: 85vh;
    object-fit: contain;
    background: #ffffff;
    border-radius: 2px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.6);
    cursor: pointer;
}