body {
    margin: 0;
    padding: 0;
    background-color: #525659; /* PDF Viewer Dark Gray */
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    overflow: hidden;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.pdf-container {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.toolbar {
    background-color: #323639;
    color: #f1f1f1;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    z-index: 10;
}

.toolbar-left, .toolbar-center, .toolbar-right {
    display: flex;
    gap: 16px;
    align-items: center;
}

.title {
    font-size: 14px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.document-area {
    flex: 1;
    background-color: #525659;
    display: flex;
    justify-content: center;
    overflow-y: auto;
    padding: 20px;
}

.paper-sheet {
    background-color: white;
    width: 600px; /* A4 ratio-ish width */
    height: 850px;
    box-shadow: 0 0 10px rgba(0,0,0,0.5);
    position: relative;
    overflow: hidden;
}

canvas {
    display: block;
    width: 100%;
    height: 100%;
}

.game-ui {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.stats {
    position: absolute;
    top: 10px;
    right: 20px;
    text-align: right;
    font-family: 'Times New Roman', Times, serif;
    font-size: 16px;
    color: #333;
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    pointer-events: auto;
    font-family: 'Times New Roman', Times, serif;
}

.overlay h1 {
    font-size: 32px;
    margin-bottom: 10px;
    color: #000;
}

.overlay p {
    font-size: 18px;
    color: #444;
    margin: 5px 0;
}

.stealth-hint {
    margin-top: 20px;
    font-size: 14px;
    color: #666;
}

button {
    margin-top: 20px;
    padding: 10px 20px;
    font-size: 16px;
    background-color: #333;
    color: white;
    border: none;
    cursor: pointer;
    font-family: 'Segoe UI', sans-serif;
}

button:hover {
    background-color: #555;
}

.hidden {
    display: none !important;
}

/* Stealth Overlay */
.stealth-overlay {
    position: fixed;
    top: 48px; /* Below toolbar */
    left: 0;
    width: 100%;
    height: calc(100% - 48px);
    background-color: #525659;
    display: flex;
    justify-content: center;
    padding: 20px;
    z-index: 100;
}

.static-paper {
    padding: 40px;
    box-sizing: border-box;
    font-family: 'Times New Roman', Times, serif;
}

.static-paper h2 {
    text-align: center;
    margin-bottom: 20px;
}

.abstract-text {
    font-size: 14px;
    line-height: 1.6;
    text-align: justify;
    margin-bottom: 20px;
    color: #000;
}

.chart-placeholder {
    width: 100%;
    height: 200px;
    border: 1px solid #ccc;
    display: flex;
    justify-content: center;
    align-items: center;
    color: #888;
    background-color: #f9f9f9;
    margin-top: 40px;
}

/* Mode Selection Buttons */
.mode-buttons {
    display: flex;
    gap: 10px;
    margin-top: 20px;
    flex-wrap: wrap;
    justify-content: center;
}

.mode-buttons button {
    padding: 12px 20px;
    font-size: 14px;
    background-color: #444;
    border: 2px solid #666;
    transition: all 0.2s;
}

.mode-buttons button:hover {
    background-color: #555;
    border-color: #888;
    transform: translateY(-2px);
}

.mode-desc {
    margin-top: 15px;
    font-size: 12px;
    color: #777;
    text-align: left;
    max-width: 350px;
}

.mode-desc p {
    margin: 4px 0;
}

/* Academic Paper Styles for Stealth */
.static-paper h2 {
    font-size: 18px;
    text-align: center;
    margin-bottom: 10px;
    line-height: 1.4;
}

.static-paper h3 {
    font-size: 14px;
    margin-top: 20px;
    margin-bottom: 10px;
}

.authors {
    text-align: center;
    font-size: 13px;
    margin: 5px 0;
}

.affiliations {
    text-align: center;
    font-size: 11px;
    color: #666;
    font-style: italic;
    margin-bottom: 20px;
    line-height: 1.5;
}

.references {
    font-size: 11px;
    margin-top: 30px;
    line-height: 1.6;
    color: #444;
}