/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #0f4c75 0%, #3282b8 50%, #0f4c75 100%);
    background-attachment: fixed;
    color: #ffffff;
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* Animated Background Elements */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(255, 215, 0, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(50, 205, 50, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(255, 69, 0, 0.1) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
}

/* Header with Level System */
.header {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    color: #0d3b66;
    text-align: center;
    padding: 25px;
    box-shadow: 0 4px 15px rgba(255, 215, 0, 0.4);
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent 30%, rgba(255, 255, 255, 0.1) 50%, transparent 70%);
    animation: shimmer 3s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%) translateY(-100%) rotate(45deg); }
    100% { transform: translateX(100%) translateY(100%) rotate(45deg); }
}

.header h1 {
    font-size: 2.8em;
    font-weight: bold;
    margin-bottom: 8px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
    position: relative;
    z-index: 2;
}

.header h1::before {
    content: '🎮';
    margin-right: 15px;
    font-size: 0.8em;
}

.header p {
    font-size: 1.3em;
    opacity: 0.9;
    position: relative;
    z-index: 2;
    font-weight: 600;
}

/* Level Badge */
.level-badge {
    position: absolute;
    top: 15px;
    right: 20px;
    background: linear-gradient(135deg, #ff6b35 0%, #f7931e 100%);
    color: white;
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: bold;
    font-size: 1em;
    box-shadow: 0 3px 10px rgba(255, 107, 53, 0.4);
    z-index: 3;
}

.level-badge::before {
    content: '⭐ LEVEL ';
}

/* App Container with Gaming Aesthetics */
.app-container {
    max-width: 1100px;
    margin: 30px auto;
    background: linear-gradient(145deg, #ffffff 0%, #f8f9fa 100%);
    border-radius: 20px;
    box-shadow: 
        0 10px 30px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
    padding: 25px 40px;
    border: 3px solid #ffd700;
    position: relative;
}

.app-container::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: linear-gradient(45deg, #ffd700, #ff6b35, #32cd32, #ffd700);
    border-radius: 22px;
    z-index: -1;
    animation: borderGlow 2s linear infinite;
}

@keyframes borderGlow {
    0% { filter: hue-rotate(0deg); }
    100% { filter: hue-rotate(360deg); }
}

/* Enhanced Progress Container with XP Bar */
.progress-container {
    background: linear-gradient(135deg, #ffffff 0%, #f0f8ff 100%);
    color: #0d3b66;
    padding: 25px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 3px solid #ffd700;
    position: relative;
    border-radius: 15px;
    margin-bottom: 20px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

/* XP Bar */
.xp-bar-container {
    position: absolute;
    bottom: -8px;
    left: 20px;
    right: 20px;
    height: 16px;
    background-color: rgba(13, 59, 102, 0.2);
    border-radius: 8px;
    overflow: hidden;
    border: 2px solid #0d3b66;
}

.xp-bar {
    height: 100%;
    background: linear-gradient(90deg, #32cd32 0%, #90ee90 50%, #32cd32 100%);
    border-radius: 6px;
    transition: width 0.8s ease;
    position: relative;
    animation: xpPulse 2s infinite;
    min-width: 10%;
}

@keyframes xpPulse {
    0%, 100% { box-shadow: 0 0 5px rgba(50, 205, 50, 0.5); }
    50% { box-shadow: 0 0 15px rgba(50, 205, 50, 0.8); }
}

.xp-text {
    position: absolute;
    top: -25px;
    left: 0;
    font-size: 0.9em;
    font-weight: bold;
    color: #0d3b66;
}

/* Enhanced Fuel Gauge */
.fuel-gauge {
    position: relative;
    width: 140px;
    height: 70px;
    background: linear-gradient(180deg, #0d3b66 0%, #1e5f99 100%);
    border: 4px solid #ffd700;
    border-radius: 70px 70px 0 0;
    overflow: hidden;
    box-shadow: 
        0 5px 15px rgba(0, 0, 0, 0.3),
        inset 0 2px 5px rgba(255, 215, 0, 0.2);
}

.fuel-gauge::before {
    content: '⛽';
    position: absolute;
    top: -5px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 1.2em;
    color: #ffd700;
}

.fuel-needle {
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 4px;
    height: 50px;
    background: linear-gradient(180deg, #ffd700 0%, #ffed4e 100%);
    transform-origin: bottom center;
    transform: translateX(-50%) rotate(-90deg);
    transition: transform 0.8s ease;
    border-radius: 2px;
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.6);
}

.fuel-labels {
    position: absolute;
    bottom: -30px;
    width: 100%;
    display: flex;
    justify-content: space-between;
    font-weight: bold;
    color: #0d3b66;
    padding: 0 15px;
    font-size: 0.9em;
}

.progress-text {
    font-size: 1.2em;
    font-weight: bold;
    color: #0d3b66;
    text-shadow: 1px 1px 2px rgba(255, 215, 0, 0.3);
}

/* Achievement Badges */
.achievement-container {
    position: absolute;
    top: 15px;
    left: 20px;
    display: flex;
    gap: 8px;
}

.achievement-badge {
    width: 35px;
    height: 35px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2em;
    border: 2px solid #ffd700;
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.2);
}

.achievement-badge.earned {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    animation: bounce 1s ease-in-out;
}

.achievement-badge.locked {
    background: #cccccc;
    opacity: 0.5;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-10px); }
    60% { transform: translateY(-5px); }
}

/* Content Container */
.content-container {
    flex: 1;
    padding: 40px;
    max-width: 1000px;
    margin: 0 auto;
    width: 100%;
}

/* Enhanced Slides with Gaming Feel */
.slide {
    display: none;
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    color: #0d3b66;
    border-radius: 15px;
    padding: 40px;
    min-height: 500px;
    box-shadow: 
        0 10px 25px rgba(0, 0, 0, 0.15),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
    border: 2px solid #ffd700;
    position: relative;
    overflow: hidden;
}

.slide::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent 0%, rgba(255, 215, 0, 0.1) 50%, transparent 100%);
    transition: left 0.6s ease;
}

.slide.active {
    display: block;
    animation: slideInGame 0.5s ease-out;
}

.slide.active::before {
    left: 100%;
}

@keyframes slideInGame {
    from {
        opacity: 0;
        transform: translateY(30px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.slide.slide-in-right {
    animation: slideInFromRightGame 0.4s ease-out;
}

.slide.slide-in-left {
    animation: slideInFromLeftGame 0.4s ease-out;
}

@keyframes slideInFromRightGame {
    from {
        opacity: 0;
        transform: translateX(50px) rotateY(10deg);
    }
    to {
        opacity: 1;
        transform: translateX(0) rotateY(0deg);
    }
}

@keyframes slideInFromLeftGame {
    from {
        opacity: 0;
        transform: translateX(-50px) rotateY(-10deg);
    }
    to {
        opacity: 1;
        transform: translateX(0) rotateY(0deg);
    }
}

.slide h2 {
    color: #0d3b66;
    font-size: 2.4em;
    margin-bottom: 30px;
    border-bottom: 4px solid #ffd700;
    padding-bottom: 15px;
    text-shadow: 1px 1px 3px rgba(255, 215, 0, 0.3);
    position: relative;
}

.slide h2::before {
    content: '📚';
    margin-right: 15px;
    font-size: 0.8em;
}

.slide h3 {
    color: #0d3b66;
    font-size: 1.6em;
    margin: 25px 0 15px 0;
    position: relative;
}

.slide h3::before {
    content: '▶️';
    margin-right: 10px;
    font-size: 0.8em;
}

.slide h4 {
    color: #0d3b66;
    font-size: 1.4em;
    margin: 20px 0 10px 0;
}

/* Enhanced Content Review */
.content-review {
    font-size: 1.1em;
    line-height: 1.8;
}

.content-review ul {
    margin-left: 30px;
    margin-bottom: 20px;
}

.content-review li {
    margin-bottom: 12px;
    position: relative;
}

.content-review li::before {
    content: '🎯';
    position: absolute;
    left: -25px;
}

/* Gaming-Style Highlight Box */
.highlight-box {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    color: #0d3b66;
    padding: 30px;
    border-radius: 12px;
    margin: 25px 0;
    border: 3px solid #0d3b66;
    position: relative;
    box-shadow: 
        0 8px 20px rgba(255, 215, 0, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.5);
    animation: highlightPulse 3s infinite;
}

@keyframes highlightPulse {
    0%, 100% { box-shadow: 0 8px 20px rgba(255, 215, 0, 0.3), inset 0 1px 0 rgba(255, 255, 255, 0.5); }
    50% { box-shadow: 0 8px 30px rgba(255, 215, 0, 0.5), inset 0 1px 0 rgba(255, 255, 255, 0.8); }
}

.highlight-box::before {
    content: '💡';
    position: absolute;
    top: -10px;
    left: 20px;
    background: #0d3b66;
    color: #ffd700;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2em;
}

.highlight-box h4 {
    margin-bottom: 15px;
    font-size: 1.5em;
}

/* Enhanced Quiz Container */
.quiz-container {
    margin-top: 30px;
}

.question-card {
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    border: 3px solid #0d3b66;
    border-radius: 15px;
    padding: 35px;
    margin-bottom: 25px;
    position: relative;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.question-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: linear-gradient(90deg, #ff6b35 0%, #ffd700 50%, #32cd32 100%);
}

.question-text {
    font-size: 1.4em;
    font-weight: bold;
    margin-bottom: 25px;
    color: #0d3b66;
    position: relative;
    padding-left: 40px;
}

.question-text::before {
    content: '❓';
    position: absolute;
    left: 0;
    top: 0;
    font-size: 1.2em;
}

/* Gaming-Style Options */
.options {
    display: grid;
    gap: 15px;
    margin-bottom: 25px;
}

.option {
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    border: 3px solid #0d3b66;
    border-radius: 12px;
    padding: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1.1em;
    color: #0d3b66;
    position: relative;
    transform: translateY(0);
}

.option::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 0;
    height: 100%;
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.2) 0%, rgba(255, 215, 0, 0.1) 100%);
    border-radius: 9px;
    transition: width 0.3s ease;
}

.option:hover {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    border-color: #0d3b66;
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(255, 215, 0, 0.4);
}

.option:hover::before {
    width: 100%;
}

.option.selected {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    border-color: #0d3b66;
    font-weight: bold;
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(255, 215, 0, 0.4);
}

.option.correct {
    background: linear-gradient(135deg, #32cd32 0%, #90ee90 100%);
    border-color: #228b22;
    color: #ffffff;
    animation: correctPulse 0.6s ease;
}

.option.incorrect {
    background: linear-gradient(135deg, #ff6b35 0%, #ff8c69 100%);
    border-color: #dc143c;
    color: #ffffff;
    animation: shake 0.6s ease;
}

@keyframes correctPulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

/* Enhanced Multiple Select */
.multiple-select {
    display: grid;
    gap: 12px;
    margin-bottom: 25px;
}

.checkbox-option {
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    border: 3px solid #0d3b66;
    border-radius: 12px;
    padding: 18px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

.checkbox-option:hover {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    transform: translateX(5px);
}

.checkbox-option input[type="checkbox"] {
    margin-right: 15px;
    transform: scale(1.4);
    cursor: pointer;
    accent-color: #0d3b66;
}

.checkbox-option span {
    font-size: 1.1em;
    color: #0d3b66;
    font-weight: 500;
}

/* Enhanced Drag and Drop */
.drag-drop-container {
    display: flex;
    gap: 40px;
    margin: 25px 0;
    position: relative;
}

.drag-section, .drop-section {
    flex: 1;
    background: linear-gradient(135deg, #f0f8ff 0%, #ffffff 100%);
    border-radius: 15px;
    padding: 20px;
    border: 2px solid #0d3b66;
}

.drag-section h4, .drop-section h4 {
    margin-bottom: 15px;
    color: #0d3b66;
    text-align: center;
    font-size: 1.3em;
    text-shadow: 1px 1px 2px rgba(255, 215, 0, 0.3);
}

.drag-items, .drop-zones {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.drag-item {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    color: #0d3b66;
    padding: 18px;
    border: 3px solid #0d3b66;
    border-radius: 12px;
    cursor: grab;
    user-select: none;
    transition: all 0.3s ease;
    text-align: center;
    font-weight: bold;
    position: relative;
    box-shadow: 0 4px 10px rgba(255, 215, 0, 0.3);
}

.drag-item:hover {
    transform: scale(1.05) rotate(1deg);
    box-shadow: 0 8px 20px rgba(255, 215, 0, 0.5);
}

.drag-item:active {
    cursor: grabbing;
    transform: scale(1.1) rotate(3deg);
}

.drop-zone {
    border: 4px dashed #0d3b66;
    border-radius: 12px;
    padding: 25px;
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    color: #0d3b66;
    text-align: center;
    font-weight: 600;
}

.drop-zone.drag-over {
    border-color: #ffd700;
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    color: #0d3b66;
    transform: scale(1.02);
    animation: dropZonePulse 0.6s infinite;
}

@keyframes dropZonePulse {
    0%, 100% { box-shadow: 0 0 10px rgba(255, 215, 0, 0.5); }
    50% { box-shadow: 0 0 20px rgba(255, 215, 0, 0.8); }
}

.drop-zone.filled {
    border-color: #32cd32;
    background: linear-gradient(135deg, #32cd32 0%, #90ee90 100%);
    color: #ffffff;
    font-weight: bold;
    animation: fillSuccess 0.5s ease;
}

@keyframes fillSuccess {
    0% { transform: scale(1); }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

/* Enhanced Feedback */
.feedback {
    margin-top: 25px;
    padding: 25px;
    border-radius: 12px;
    display: none;
    font-size: 1.1em;
    font-weight: bold;
    border: 3px solid;
    position: relative;
    overflow: hidden;
}

.feedback::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.2) 50%, transparent 100%);
    animation: feedbackShine 2s infinite;
}

@keyframes feedbackShine {
    0% { left: -100%; }
    100% { left: 100%; }
}

.feedback.correct {
    background: linear-gradient(135deg, #32cd32 0%, #90ee90 100%);
    border-color: #228b22;
    color: #ffffff;
}

.feedback.correct::after {
    content: '🎉';
    position: absolute;
    top: 10px;
    right: 15px;
    font-size: 1.5em;
    animation: celebration 1s ease;
}

@keyframes celebration {
    0%, 100% { transform: scale(1) rotate(0deg); }
    25% { transform: scale(1.2) rotate(10deg); }
    75% { transform: scale(1.2) rotate(-10deg); }
}

.feedback.incorrect {
    background: linear-gradient(135deg, #ff6b35 0%, #ff8c69 100%);
    border-color: #dc143c;
    color: #ffffff;
}

/* Enhanced Results */
.results {
    text-align: center;
    padding: 40px;
    position: relative;
}

.results h3 {
    color: #0d3b66;
    font-size: 2.2em;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(255, 215, 0, 0.3);
}

.results p {
    color: #0d3b66;
    font-size: 1.3em;
    margin-bottom: 20px;
    font-weight: 600;
}

.score {
    font-size: 3em;
    font-weight: bold;
    color: #0d3b66;
    margin: 30px 0;
    padding: 25px;
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    border: 4px solid #0d3b66;
    border-radius: 15px;
    display: inline-block;
    box-shadow: 
        0 10px 25px rgba(255, 215, 0, 0.4),
        inset 0 2px 5px rgba(255, 255, 255, 0.5);
    animation: scoreReveal 1s ease;
    position: relative;
}

@keyframes scoreReveal {
    0% { transform: scale(0) rotate(180deg); opacity: 0; }
    50% { transform: scale(1.2) rotate(10deg); }
    100% { transform: scale(1) rotate(0deg); opacity: 1; }
}

.score::before {
    content: '🏆';
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.6em;
    animation: trophyBounce 2s infinite;
}

@keyframes trophyBounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(-10px); }
}

/* Enhanced Navigation */
.navigation {
    background: linear-gradient(135deg, #ffffff 0%, #f0f8ff 100%);
    padding: 25px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 3px solid #ffd700;
    border-radius: 0 0 18px 18px;
    position: relative;
}

/* Gaming-Style Buttons */
.btn {
    background: linear-gradient(135deg, #0d3b66 0%, #1e5f99 100%);
    color: #ffffff;
    border: 3px solid #0d3b66;
    padding: 15px 35px;
    font-size: 1.1em;
    font-weight: bold;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
    letter-spacing: 1px;
    box-shadow: 0 5px 15px rgba(13, 59, 102, 0.3);
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.2) 50%, transparent 100%);
    transition: left 0.5s ease;
}

.btn:hover {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    color: #0d3b66;
    border-color: #0d3b66;
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(255, 215, 0, 0.4);
}

.btn:hover::before {
    left: 100%;
}

.btn:active {
    transform: translateY(-1px);
}

.btn:disabled {
    background: linear-gradient(135deg, #cccccc 0%, #e0e0e0 100%);
    color: #666666;
    border-color: #cccccc;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn.btn-secondary {
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    color: #0d3b66;
    border-color: #0d3b66;
}

.btn.btn-secondary:hover {
    background: linear-gradient(135deg, #0d3b66 0%, #1e5f99 100%);
    color: #ffffff;
    transform: translateY(-3px);
}

.btn.btn-secondary:disabled {
    background: linear-gradient(135deg, #f5f5f5 0%, #e8e8e8 100%);
    color: #999999;
    border-color: #cccccc;
    transform: none;
}

/* Enhanced Submit Button */
.submit-button {
    background: linear-gradient(135deg, #ff6b35 0%, #f7931e 100%);
    color: #ffffff;
    border: 3px solid #ff6b35;
    padding: 12px 30px;
    font-size: 1.1em;
    font-weight: bold;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    position: relative;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(255, 107, 53, 0.3);
}

.submit-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.3) 50%, transparent 100%);
    transition: left 0.5s ease;
}

.submit-button:hover {
    background: linear-gradient(135deg, #ffd700 0%, #ffed4e 100%);
    color: #0d3b66;
    border-color: #0d3b66;
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 8px 20px rgba(255, 215, 0, 0.4);
}

.submit-button:hover::before {
    left: 100%;
}

.submit-button:disabled {
    background: linear-gradient(135deg, #cccccc 0%, #e0e0e0 100%);
    color: #666666;
    border-color: #cccccc;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.question-card .submit-multiple-select {
    display: block;
    margin: 20px auto 0 auto;
}

/* Combo/Streak Indicator */
.combo-indicator {
    position: fixed;
    top: 50%;
    right: 20px;
    transform: translateY(-50%);
    background: linear-gradient(135deg, #ff6b35 0%, #ffd700 100%);
    color: #ffffff;
    padding: 15px 20px;
    border-radius: 50px;
    font-weight: bold;
    font-size: 1.2em;
    box-shadow: 0 5px 20px rgba(255, 107, 53, 0.4);
    z-index: 1000;
    opacity: 0;
    transition: all 0.3s ease;
    border: 3px solid #ffffff;
}

.combo-indicator.show {
    opacity: 1;
    animation: comboPopup 2s ease;
}

@keyframes comboPopup {
    0% { transform: translateY(-50%) scale(0); }
    20% { transform: translateY(-50%) scale(1.2); }
    100% { transform: translateY(-50%) scale(1); }
}

.combo-indicator::before {
    content: '🔥 COMBO ';
}

/* Particle Effects Container */
.particle-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
    overflow: hidden;
}

.particle {
    position: absolute;
    width: 8px;
    height: 8px;
    background: #ffd700;
    border-radius: 50%;
    animation: particleFall 2s linear forwards;
}

@keyframes particleFall {
    0% {
        opacity: 1;
        transform: translateY(0) rotate(0deg);
    }
    100% {
        opacity: 0;
        transform: translateY(100vh) rotate(360deg);
    }
}

/* Sound Wave Animation for Audio Feedback */
.sound-wave {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 3px;
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 1000;
}

.sound-wave.active {
    opacity: 1;
}

.sound-bar {
    width: 4px;
    height: 20px;
    background: linear-gradient(135deg, #32cd32 0%, #90ee90 100%);
    border-radius: 2px;
    animation: soundPulse 0.8s infinite ease-in-out;
}

.sound-bar:nth-child(2) { animation-delay: -0.7s; }
.sound-bar:nth-child(3) { animation-delay: -0.6s; }
.sound-bar:nth-child(4) { animation-delay: -0.5s; }
.sound-bar:nth-child(5) { animation-delay: -0.4s; }

@keyframes soundPulse {
    0%, 40%, 100% { transform: scaleY(0.4); }
    20% { transform: scaleY(1); }
}

/* Enhanced Digital Dashboard Timer */
.dashboard-timer {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
}

.timer-frame {
    display: inline-block;
    background: linear-gradient(135deg, #0d3b66 0%, #1e5f99 100%);
    border: 4px solid #ffd700;
    border-radius: 12px;
    padding: 8px 20px;
    box-shadow: 
        0 5px 15px rgba(0, 0, 0, 0.3),
        inset 0 1px 0 rgba(255, 215, 0, 0.2);
    position: relative;
}

.timer-frame::before {
    content: '⏱️';
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: #ffd700;
    color: #0d3b66;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8em;
}

.timer-frame #timer {
    font-family: 'Courier New', monospace;
    font-size: 2em;
    color: #ffd700;
    text-shadow: 0 0 10px rgba(255, 215, 0, 0.5);
    font-weight: bold;
}

.timer-frame.warning {
    animation: timerWarning 1s infinite;
}

@keyframes timerWarning {
    0%, 100% { 
        border-color: #ffd700;
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3), inset 0 1px 0 rgba(255, 215, 0, 0.2);
    }
    50% { 
        border-color: #ff6b35;
        box-shadow: 0 5px 20px rgba(255, 107, 53, 0.5), inset 0 1px 0 rgba(255, 107, 53, 0.3);
    }
}

.timer-frame.critical {
    animation: timerCritical 0.5s infinite;
}

@keyframes timerCritical {
    0%, 100% { 
        border-color: #ff6b35;
        transform: translateX(-50%) scale(1);
    }
    50% { 
        border-color: #dc143c;
        transform: translateX(-50%) scale(1.05);
    }
}

/* Power-up Indicator */
.powerup-indicator {
    position: fixed;
    bottom: 20px;
    left: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    z-index: 1000;
}

.powerup {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5em;
    border: 3px solid #ffd700;
    background: linear-gradient(135deg, #0d3b66 0%, #1e5f99 100%);
    color: #ffd700;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    cursor: pointer;
}

.powerup:hover {
    transform: scale(1.1);
    box-shadow: 0 8px 20px rgba(255, 215, 0, 0.4);
}

.powerup.active {
    animation: powerupPulse 1s infinite;
}

@keyframes powerupPulse {
    0%, 100% { box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3); }
    50% { box-shadow: 0 8px 25px rgba(255, 215, 0, 0.6); }
}

/* Mobile Responsive Enhancements */
@media (max-width: 768px) {
    .content-container {
        padding: 20px;
    }

    .slide {
        padding: 25px;
    }

    .header h1 {
        font-size: 2.2em;
    }

    .progress-container {
        flex-direction: column;
        gap: 15px;
        text-align: center;
        padding: 20px;
    }

    .achievement-container {
        position: static;
        justify-content: center;
        margin-bottom: 15px;
    }

    .level-badge {
        position: static;
        margin-bottom: 10px;
    }

    .drag-drop-container {
        flex-direction: column;
        gap: 20px;
    }

    .navigation {
        flex-direction: column;
        gap: 15px;
        padding: 20px;
    }

    .btn, .submit-button {
        width: 100%;
        max-width: 250px;
    }

    .combo-indicator {
        right: 10px;
        font-size: 1em;
        padding: 10px 15px;
    }

    .powerup-indicator {
        bottom: 10px;
        left: 10px;
        flex-direction: row;
        gap: 8px;
    }

    .powerup {
        width: 40px;
        height: 40px;
        font-size: 1.2em;
    }
}

@media (max-width: 600px) {
    .slide {
        padding: 15px;
    }

    .header h1 {
        font-size: 1.8em;
    }

    .header p {
        font-size: 1.1em;
    }

    .btn, .submit-button {
        padding: 12px 25px;
        font-size: 1em;
    }

    .question-card {
        padding: 20px;
    }

    .question-text {
        font-size: 1.2em;
        padding-left: 35px;
    }

    .option {
        padding: 15px;
        font-size: 1em;
    }

    .checkbox-option {
        padding: 15px;
    }

    .timer-frame #timer {
        font-size: 1.6em;
    }

    .score {
        font-size: 2.2em;
        padding: 20px;
    }

    .fuel-gauge {
        width: 120px;
        height: 60px;
    }

    .xp-bar-container {
        height: 12px;
    }
}

/* Additional Gaming Elements */
.screen-flash {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.8);
    z-index: 9998;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.1s ease;
}

.screen-flash.active {
    opacity: 1;
}

/* Loading Spinner for Transitions */
.loading-spinner {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    border: 6px solid #f3f3f3;
    border-top: 6px solid #ffd700;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    z-index: 10000;
    display: none;
}

.loading-spinner.show {
    display: block;
}

@keyframes spin {
    0% { transform: translate(-50%, -50%) rotate(0deg); }
    100% { transform: translate(-50%, -50%) rotate(360deg); }
}