:root {
    /* Yellow/Amber Theme Palette */
    --primary-color: #d97706;       /* Amber 600 - Dark enough for white text */
    --primary-color-hover: #b45309; /* Amber 700 */
    --primary-color-light: #fcd34d; /* Amber 300 */
    --accent-color: #f59e0b;        /* Amber 500 */
    --accent-color-hover: #d97706;
    
    --bg-color: #fffbeb;            /* Amber 50 (Very light yellow tint) */
    --bg-gradient: linear-gradient(135deg, #fffbeb 0%, #fef3c7 100%);
    
    --surface-color: #ffffff;
    --surface-elevated: #ffffff;
    --text-color: #451a03;          /* Dark Brown/Black for contrast on yellow */
    --text-muted-color: #78350f;    /* Muted Brown */
    --border-color: #fde68a;        /* Amber 200 */
    
    --success-bg: #ecfdf5;
    --success-border: #10b981;
    --success-color: #065f46;
    
    --danger-bg: #fef2f2;
    --danger-border: #ef4444;
    --danger-color: #991b1b;
    
    /* Info boxes now match the yellow theme */
    --info-bg: #fff7ed;             /* Orange 50 */
    --info-border: #fbbf24;         /* Amber 400 */
    --info-color: #9a3412;          /* Orange 800 */
    
    --warning-bg: #fffbeb;
    --warning-border: #f59e0b;
    --warning-color: #92400e;
    
    --flag-color: #ea580c;          /* Red/Orange to stand out against yellow */
    
    --desc-bg: #fff8e1;             /* Light Yellow/Cream */
    --desc-border: #fcd34d;
    --desc-text: #78350f;
    
    --smart-bg: #f0fdf4;            /* Keep Smart Mode Green for distinction */
    --smart-border: #16a34a;
    --smart-text: #15803d;

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --border-radius-lg: 16px;
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Inter", Helvetica, Arial, sans-serif;
    --font-mono: "JetBrains Mono", "Fira Code", "Consolas", "Courier New", monospace;
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --primary-color: #fbbf24;       /* Amber 400 - Bright for dark mode */
        --primary-color-hover: #f59e0b; /* Amber 500 */
        --primary-color-light: #d97706; /* Amber 600 */
        --accent-color: #fcd34d;        /* Amber 300 */
        --accent-color-hover: #fbbf24;
        
        --bg-color: #1c1917;            /* Stone 900 */
        --bg-gradient: linear-gradient(135deg, #1c1917 0%, #292524 100%);
        
        --surface-color: #292524;       /* Stone 800 */
        --surface-elevated: #44403c;    /* Stone 700 */
        
        --text-color: #fef3c7;          /* Amber 100 */
        --text-muted-color: #a8a29e;    /* Stone 400 */
        --border-color: #57534e;        /* Stone 600 */
        
        --success-bg: #064e3b;
        --success-border: #10b981;
        --success-color: #6ee7b7;
        
        --danger-bg: #7f1d1d;
        --danger-border: #ef4444;
        --danger-color: #fca5a5;
        
        --info-bg: #451a03;
        --info-border: #d97706;
        --info-color: #fcd34d;
        
        --warning-bg: #451a03;
        --warning-border: #f59e0b;
        --warning-color: #fbbf24;
        
        --flag-color: #fb923c;          /* Orange 400 */
        
        --desc-bg: #292524;
        --desc-border: #78350f;
        --desc-text: #fde68a;
        
        --smart-bg: #064e3b;
        --smart-border: #22c55e;
        --smart-text: #bbf7d0;
    }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }

body {
    font-family: var(--font-sans);
    line-height: 1.6;
    margin: 0;
    padding: 20px;
    background: var(--bg-gradient);
    color: var(--text-color);
    transition: var(--transition-slow);
    min-height: 100vh;
    font-feature-settings: "kern" 1, "liga" 1;
}

#pageWrapper {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 24px;
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
}

.container {
    flex-grow: 1;
    max-width: 1000px;
    background: var(--surface-color);
    padding: 32px 40px;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color), var(--primary-color));
    background-size: 200% 100%;
    animation: shimmer 3s ease-in-out infinite;
}

@keyframes shimmer {
    0%, 100% { background-position: 200% 0; }
    50% { background-position: -200% 0; }
}

#questionNavigator {
    position: sticky;
    top: 20px;
    width: 240px;
    flex-shrink: 0;
    height: calc(100vh - 40px);
    max-height: 800px;
    background: var(--surface-elevated);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    backdrop-filter: blur(10px);
    overflow: hidden;
}

#timerDisplay {
    padding: 20px;
    text-align: center;
    font-size: 1.5em;
    font-weight: 700;
    font-family: var(--font-mono);
    color: var(--text-color);
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    position: relative;
}

#timerDisplay::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--primary-color)10, var(--accent-color)10);
    border-radius: var(--border-radius);
    z-index: -1;
}

#navigatorList {
    overflow-y: auto;
    padding: 16px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    scrollbar-width: thin;
    scrollbar-color: var(--border-color) transparent;
}

#navigatorList::-webkit-scrollbar { width: 6px; }
#navigatorList::-webkit-scrollbar-track { background: transparent; }
#navigatorList::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 3px; }

.nav-btn {
    padding: 12px 8px;
    font-size: 14px;
    font-weight: 600;
    border-radius: var(--border-radius-sm);
    border: 2px solid var(--border-color);
    background: var(--surface-color);
    color: var(--text-muted-color);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    position: relative;
    overflow: hidden;
}

.nav-btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    opacity: 0;
    transition: var(--transition);
    z-index: -1;
}

.nav-btn:hover {
    transform: translateY(-2px);
    border-color: var(--primary-color);
    color: var(--primary-color);
    box-shadow: var(--shadow);
}

.nav-btn.answered {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-color: transparent;
    color: white;
    font-weight: 700;
    box-shadow: var(--shadow);
}

.nav-btn.answered::before { opacity: 1; }

.nav-btn.flagged::after {
    content: '🚩';
    position: absolute;
    top: -4px;
    right: -4px;
    font-size: 16px;
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.2));
}

@media (max-width: 1200px) {
    #pageWrapper { flex-direction: column; gap: 20px; }
    .container { width: 100%; }
    #questionNavigator { position: static; width: 100%; height: auto; max-height: 300px; order: -1; }
    #navigatorList { grid-template-columns: repeat(auto-fill, minmax(80px, 1fr)); }
}

h1, h2, h3 { 
    text-align: center; 
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    border-bottom: 2px solid var(--border-color); 
    padding-bottom: 16px; 
    font-weight: 800;
    letter-spacing: -0.025em;
}

h3 { 
    border-bottom: 1px solid var(--border-color); 
    color: var(--text-color);
    background: none;
    -webkit-text-fill-color: var(--text-color);
    font-weight: 600;
}

.options-panel { 
    padding: 32px; 
    background: var(--surface-elevated);
    border: 1px solid var(--border-color); 
    border-radius: var(--border-radius-lg); 
    margin-bottom: 32px; 
    display: grid; 
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); 
    gap: 24px; 
    align-items: end;
    box-shadow: var(--shadow);
}

.option-group { display: flex; flex-direction: column; }

.option-group label { 
    font-weight: 600; 
    margin-bottom: 8px; 
    font-size: 0.875rem; 
    color: var(--text-muted-color);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.option-group input[type="number"], 
.option-group select { 
    padding: 12px 16px; 
    border-radius: var(--border-radius-sm); 
    border: 2px solid var(--border-color); 
    background: var(--surface-color); 
    color: var(--text-color); 
    font-size: 1em; 
    font-weight: 500;
    width: 100%; 
    transition: var(--transition);
    font-family: inherit;
}

.option-group input[type="number"]:focus,
.option-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-color)20;
}

.option-group input:disabled, 
.option-group select:disabled { 
    background-color: var(--border-color); 
    cursor: not-allowed; 
    opacity: 0.6; 
}

.option-group-checkbox { display: flex; align-items: center; gap: 12px; padding-bottom: 10px; }
.option-group-checkbox label { margin-bottom: 0; text-transform: none; letter-spacing: normal; font-weight: 500; }

#dashboardContainer, 
#categoryDescriptions { 
    margin-bottom: 24px; 
    padding: 24px; 
    border: 1px solid var(--border-color); 
    border-radius: var(--border-radius-lg); 
    background: var(--surface-elevated);
    box-shadow: var(--shadow);
}

.chart-container { display: grid; grid-template-columns: 1fr; gap: 32px; }
.chart-wrapper, .chart-summary-container { position: relative; height: auto; }

.chart-summary-container { 
    margin-top: 32px; 
    padding: 24px; 
    border: 1px solid var(--border-color); 
    border-radius: var(--border-radius-lg);
    background: var(--surface-elevated);
    box-shadow: var(--shadow);
}

#categoryDescriptions summary { 
    font-weight: 700; 
    cursor: pointer; 
    color: var(--primary-color);
    padding: 8px;
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
}

#categoryDescriptions summary:hover { background: var(--primary-color)10; }

#categoryList { 
    list-style-type: none; 
    padding-left: 0; 
    margin-top: 16px; 
    column-count: 2; 
    column-gap: 24px; 
}

#categoryList li { 
    margin-bottom: 12px; 
    font-size: 0.9em;
    padding: 8px;
    border-radius: var(--border-radius-sm);
    transition: var(--transition);
}

#categoryList li:hover { background: var(--surface-color); }
#categoryList li strong { display: inline-block; width: 70px; font-family: var(--font-mono); color: var(--accent-color); font-weight: 700; }
@media (max-width: 600px) { #categoryList { column-count: 1; } }

button { 
    background: linear-gradient(135deg, var(--primary-color), var(--primary-color-hover)); 
    color: white; 
    border: none; 
    padding: 14px 28px; 
    border-radius: var(--border-radius); 
    cursor: pointer; 
    font-size: 16px; 
    font-weight: 600; 
    font-family: inherit;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: var(--transition);
}

button:hover::before { left: 100%; }
button:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); background: linear-gradient(135deg, var(--primary-color-hover), var(--accent-color)); }
button:active { transform: translateY(-1px); }
button:disabled { background: var(--text-muted-color); cursor: not-allowed; transform: none; box-shadow: none; opacity: 0.6; }
button:disabled::before { display: none; }

.clear-data-btn { 
    background: transparent; 
    border: 2px solid var(--danger-border); 
    color: var(--danger-color); 
    font-size: 12px; 
    padding: 8px 16px; 
    margin-top: 16px; 
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.clear-data-btn:hover { background: var(--danger-bg); transform: translateY(-2px); box-shadow: var(--shadow); }

.submit-btn, .restart-btn { display: block; width: 240px; margin: 32px auto; font-size: 18px; padding: 16px 32px; }
.restart-btn { margin-top: 40px; margin-bottom: 16px; }

.question { 
    margin-bottom: 40px; 
    padding-bottom: 32px; 
    border-bottom: 1px solid var(--border-color);
    position: relative;
}

.question::before {
    content: '';
    position: absolute;
    left: -40px;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(180deg, var(--primary-color), var(--accent-color));
    border-radius: 2px;
}

.question-header { display: flex; align-items: flex-start; gap: 0; margin-bottom: 24px; }
.question-text { font-weight: 600; font-size: 1.2em; flex-grow: 1; line-height: 1.5; min-width: 0; padding-top: 4px; }

.question-category { 
    color: var(--text-muted-color); 
    font-weight: 600; 
    font-size: 0.875rem; 
    margin-right: 12px;
    padding: 4px 12px;
    background: var(--surface-elevated);
    border-radius: 20px;
    border: 1px solid var(--border-color);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.bookmark-btn { 
    background: none; 
    border: 2px solid var(--border-color);
    font-size: 18px; 
    cursor: pointer; 
    padding: 6px 12px; 
    line-height: 1; 
    opacity: 0.6; 
    color: var(--text-muted-color); 
    transition: var(--transition);
    border-radius: 6px; 
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0; 
    margin-right: 20px; 
    height: auto;
    width: auto;
    min-height: 36px;
}

.bookmark-btn:hover { background: var(--surface-elevated); border-color: var(--primary-color); opacity: 1; transform: translateY(-2px); }
.bookmark-btn.bookmarked { opacity: 1; transform: none; background: var(--flag-color)20; border-color: var(--flag-color); color: var(--flag-color); box-shadow: 0 2px 8px var(--flag-color)40; }

.exhibit-container { 
    border: 1px solid var(--border-color); 
    border-radius: var(--border-radius-lg); 
    background: var(--surface-elevated);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.exhibit-container strong { 
    display: block; 
    padding: 12px 16px; 
    background: var(--primary-color)10; 
    border-bottom: 1px solid var(--border-color); 
    font-size: 0.875rem; 
    color: var(--primary-color);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.question-exhibit-text { 
    padding: 20px; 
    white-space: pre-wrap; 
    word-wrap: break-word; 
    font-family: var(--font-mono); 
    font-size: 0.9em; 
    margin: 0; 
    background: var(--surface-color); 
    line-height: 1.6;
}

.question-exhibit, .question-exhibit-frame { max-width: 100%; height: auto; border-radius: var(--border-radius-lg); margin: 20px 0; border: 1px solid var(--border-color); box-shadow: var(--shadow); }

.answer-choice { 
    margin-bottom: 16px; 
    padding: 16px 20px; 
    border-radius: var(--border-radius); 
    display: block; 
    cursor: pointer; 
    transition: var(--transition); 
    position: relative; 
    padding-left: 50px; 
    border: 2px solid var(--border-color);
    background: var(--surface-elevated);
    font-weight: 500;
}

.answer-choice:hover { border-color: var(--primary-color); background: var(--primary-color)5; transform: translateX(4px); box-shadow: var(--shadow-sm); }

.fb-input { 
    padding: 12px 16px; 
    border: 2px solid var(--border-color); 
    border-radius: var(--border-radius-sm); 
    font-size: 1em; 
    margin: 0 8px; 
    width: 220px; 
    background: var(--surface-color); 
    color: var(--text-color);
    font-weight: 500;
    transition: var(--transition);
}

.fb-input:focus { outline: none; border-color: var(--primary-color); box-shadow: 0 0 0 3px var(--primary-color)20; }
.fb-input.correct { border-color: var(--success-border); background: var(--success-bg); color: var(--success-color); }
.fb-input.incorrect { border-color: var(--danger-border); background: var(--danger-bg); color: var(--danger-color); }

.result-explanation { 
    background: var(--info-bg); 
    border-left: 4px solid var(--info-border); 
    padding: 20px; 
    margin-top: 24px; 
    border-radius: var(--border-radius);
    color: var(--info-color);
    font-weight: 500;
}

.correct { background: var(--success-bg); border-color: var(--success-border); color: var(--success-color); font-weight: 600; }
.incorrect { background: var(--danger-bg); border-color: var(--danger-border); color: var(--danger-color); }
.hidden { display: none; }
.answer-choice input { position: absolute; opacity: 0; cursor: pointer; }

.checkmark { 
    position: absolute; 
    top: 50%; 
    left: 16px; 
    transform: translateY(-50%); 
    height: 24px; 
    width: 24px; 
    background: var(--surface-color); 
    border: 2px solid var(--border-color); 
    border-radius: 6px;
    transition: var(--transition);
}

.answer-choice:hover .checkmark { border-color: var(--primary-color); background: var(--primary-color)10; }
.answer-choice input:checked ~ .checkmark { background: var(--primary-color); border-color: var(--primary-color); box-shadow: 0 0 0 3px var(--primary-color)20; }
.checkmark:after { content: ""; position: absolute; display: none; }
.answer-choice input:checked ~ .checkmark:after { display: block; }
.answer-choice input[type="checkbox"] ~ .checkmark:after { left: 7px; top: 3px; width: 6px; height: 12px; border: solid white; border-width: 0 3px 3px 0; transform: rotate(45deg); }
.answer-choice input[type="radio"] ~ .checkmark { border-radius: 50%; }
.answer-choice input[type="radio"] ~ .checkmark:after { left: 50%; top: 50%; transform: translate(-50%, -50%); width: 10px; height: 10px; border-radius: 50%; background: white; }

/* Mode Description Box */
.mode-description {
    background: var(--desc-bg);
    border: 1px solid var(--desc-border);
    color: var(--desc-text);
    padding: 16px;
    border-radius: var(--border-radius);
    margin-top: 16px;
    font-size: 0.9em;
    animation: fadeInUp 0.3s ease-out;
}
.mode-description h4 { margin: 0 0 8px 0; color: inherit; text-align: left; background: none; -webkit-text-fill-color: inherit; border: none; }
.mode-description ul { margin: 0; padding-left: 20px; }
.mode-description li { margin-bottom: 8px; }

@keyframes fadeInUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes pulse { 0%, 100% { transform: scale(1); } 50% { transform: scale(1.05); } }
.question { animation: fadeInUp 0.5s ease-out; }
.nav-btn.answered { animation: pulse 0.3s ease-in-out; }
*:focus { outline: 2px solid var(--primary-color); outline-offset: 2px; }
.loading { position: relative; overflow: hidden; }
.loading::after { content: ''; position: absolute; top: 0; left: -100%; width: 100%; height: 100%; background: linear-gradient(90deg, transparent, var(--primary-color)20, transparent); animation: loading 1.5s infinite; }
@keyframes loading { to { left: 100%; } }