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

:root {
    /* Black & Orange Theme */
    --primary-color: #ff6b35;
    --secondary-color: #ff8c42;
    --accent-color: #ffa552;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --text-dark: #f5f5f5;
    --text-light: #d1d1d1;
    --text-muted: #a0a0a0;
    --bg-primary: #000000;
    --bg-secondary: #0a0a0a;
    --bg-tertiary: #141414;
    --bg-card: rgba(20, 20, 20, 0.9);
    --bg-light: #1a1a1a;
    --bg-white: #141414;
    --border-color: rgba(255, 107, 53, 0.15);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.6);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.7);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.8);
    --shadow-glow: 0 0 20px rgba(255, 107, 53, 0.4);
    --gradient: linear-gradient(135deg, #ff6b35 0%, #ff8c42 50%, #ffa552 100%);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #000000 0%, #0a0a0a 50%, #141414 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    line-height: 1.6;
    position: relative;
}

/* Animated background pattern */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(255, 107, 53, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 140, 66, 0.06) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(255, 165, 82, 0.05) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

.container {
    position: relative;
    z-index: 1;
}

.container {
    width: 100%;
    max-width: 800px;
    position: relative;
}

/* Screen Management */
.screen {
    display: none;
    animation: fadeIn 0.4s ease-in-out;
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Welcome Screen */
.welcome-content {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 50px;
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    text-align: center;
}

.welcome-content h1 {
    font-size: 3rem;
    margin-bottom: 15px;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 40px;
}

.quiz-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.info-item {
    background: rgba(255, 107, 53, 0.1);
    border: 1px solid var(--border-color);
    padding: 20px;
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    transition: all 0.3s ease;
}

.info-item:hover {
    background: rgba(255, 107, 53, 0.15);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.info-item .icon {
    font-size: 2rem;
}

.info-item .label {
    font-size: 0.95rem;
    color: var(--text-dark);
    font-weight: 600;
}

.instructions {
    background: rgba(255, 107, 53, 0.05);
    border: 1px solid var(--border-color);
    padding: 30px;
    border-radius: 12px;
    text-align: left;
    margin-bottom: 40px;
}

.instructions h3 {
    color: var(--text-dark);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.instructions ul {
    list-style-position: inside;
    color: var(--text-light);
}

.instructions li {
    margin: 10px 0;
    padding-left: 10px;
}

/* Buttons */
.btn {
    padding: 16px 40px;
    border: none;
    border-radius: 12px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-block;
}

.btn-primary {
    background: var(--gradient);
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background: rgba(255, 107, 53, 0.1);
    border: 1px solid var(--border-color);
    color: var(--text-dark);
}

.btn-secondary:hover {
    background: rgba(255, 107, 53, 0.2);
    border-color: var(--primary-color);
}

/* Quiz Screen */
#quizScreen {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.quiz-header {
    margin-bottom: 40px;
}

.progress-container {
    background: rgba(255, 255, 255, 0.05);
    height: 8px;
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
}

.progress-bar {
    height: 100%;
    background: var(--gradient);
    transition: width 0.4s ease;
    width: 0%;
}

.quiz-stats {
    display: flex;
    justify-content: space-between;
    gap: 20px;
}

.stat {
    flex: 1;
    background: rgba(255, 107, 53, 0.1);
    border: 1px solid var(--border-color);
    padding: 15px 20px;
    border-radius: 12px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.stat-label {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 600;
}

.stat-value {
    color: var(--text-dark);
    font-size: 1.3rem;
    font-weight: 700;
}

/* Question */
.question-text {
    font-size: 1.5rem;
    color: var(--text-dark);
    margin-bottom: 30px;
    line-height: 1.6;
}

/* Answers */
.answers-container {
    display: grid;
    gap: 15px;
    margin-bottom: 30px;
}

.answer-btn {
    background: rgba(255, 255, 255, 0.03);
    border: 2px solid var(--border-color);
    padding: 20px;
    border-radius: 12px;
    font-size: 1.1rem;
    text-align: left;
    cursor: pointer;
    transition: all 0.3s ease;
    color: var(--text-dark);
}

.answer-btn:hover:not(:disabled) {
    background: rgba(255, 107, 53, 0.15);
    border-color: var(--primary-color);
    transform: translateX(5px);
    box-shadow: var(--shadow-glow);
}

.answer-btn:disabled {
    cursor: not-allowed;
}

.answer-btn.correct {
    background: #d1fae5;
    border-color: var(--success-color);
    color: var(--success-color);
    font-weight: 600;
}

.answer-btn.incorrect {
    background: #fee2e2;
    border-color: var(--error-color);
    color: var(--error-color);
    font-weight: 600;
}

/* Feedback */
.feedback-container {
    display: none;
    margin-bottom: 20px;
}

.feedback {
    display: flex;
    gap: 15px;
    padding: 20px;
    border-radius: 12px;
    opacity: 0;
    transform: translateY(-10px);
    transition: all 0.4s ease;
}

.feedback.show {
    opacity: 1;
    transform: translateY(0);
}

.feedback.correct {
    background: #d1fae5;
    border: 2px solid var(--success-color);
}

.feedback.incorrect {
    background: #fee2e2;
    border: 2px solid var(--error-color);
}

.feedback-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.feedback.correct .feedback-icon {
    color: var(--success-color);
}

.feedback.incorrect .feedback-icon {
    color: var(--error-color);
}

.feedback-content {
    flex: 1;
}

.feedback-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.feedback.correct .feedback-title {
    color: var(--success-color);
}

.feedback.incorrect .feedback-title {
    color: var(--error-color);
}

.feedback-text {
    color: var(--text-dark);
    line-height: 1.6;
}

.quiz-footer {
    display: flex;
    justify-content: flex-end;
}

/* Results Screen */
.results-content {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 50px;
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    text-align: center;
    opacity: 0;
    transform: scale(0.9);
    transition: all 0.5s ease;
}

.results-content.show {
    opacity: 1;
    transform: scale(1);
}

.results-icon {
    font-size: 5rem;
    margin-bottom: 20px;
    animation: bounce 0.6s ease;
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

#resultsTitle {
    font-size: 2.5rem;
    margin-bottom: 40px;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Score Circle */
.score-circle {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 0 auto 40px;
}

.score-circle svg {
    transform: rotate(-90deg);
}

.score-circle-bg {
    fill: none;
    stroke: rgba(255, 255, 255, 0.1);
    stroke-width: 10;
}

.score-circle-progress {
    fill: none;
    stroke: #ff6b35;
    stroke-width: 10;
    stroke-linecap: round;
    stroke-dasharray: 565;
    stroke-dashoffset: 565;
    transition: stroke-dashoffset 1s ease;
    filter: drop-shadow(0 0 8px rgba(255, 107, 53, 0.6));
}

.score-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 3rem;
    font-weight: 700;
}

.score-number {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.score-total {
    color: var(--text-muted);
    font-size: 1.5rem;
}

/* Results Stats */
.results-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.result-stat {
    background: rgba(255, 107, 53, 0.1);
    border: 1px solid var(--border-color);
    padding: 25px;
    border-radius: 12px;
}

.result-stat-icon {
    font-size: 2rem;
    margin-bottom: 10px;
}

.result-stat.correct .result-stat-icon {
    color: var(--success-color);
}

.result-stat.incorrect .result-stat-icon {
    color: var(--error-color);
}

.result-stat.percentage .result-stat-icon {
    color: var(--primary-color);
}

.result-stat-label {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.result-stat-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-dark);
}

.results-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Review Screen */
.review-content {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow-lg), var(--shadow-glow);
}

.review-content h1 {
    font-size: 2rem;
    margin-bottom: 30px;
    text-align: center;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

#reviewContainer {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-bottom: 30px;
}

.review-item {
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 25px;
    transition: all 0.3s ease;
    background: rgba(255, 255, 255, 0.02);
}

.review-item.correct {
    border-color: var(--success-color);
    background: rgba(16, 185, 129, 0.1);
}

.review-item.incorrect {
    border-color: var(--error-color);
    background: rgba(239, 68, 68, 0.1);
}

.review-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.review-number {
    font-weight: 700;
    color: var(--text-dark);
}

.review-badge {
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.badge-correct {
    background: var(--success-color);
    color: white;
}

.badge-incorrect {
    background: var(--error-color);
    color: white;
}

.review-question {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 15px;
}

.review-answers {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 15px;
}

.review-answer {
    padding: 12px;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
}

.review-answer.answer-correct {
    background: rgba(16, 185, 129, 0.2);
    color: #4ade80;
    font-weight: 600;
    border-color: var(--success-color);
}

.review-answer.answer-incorrect {
    background: rgba(239, 68, 68, 0.2);
    color: #f87171;
    font-weight: 600;
    border-color: var(--error-color);
}

.review-explanation {
    background: rgba(255, 107, 53, 0.05);
    border: 1px solid var(--border-color);
    padding: 15px;
    border-radius: 8px;
    color: var(--text-light);
    line-height: 1.6;
}

.review-explanation strong {
    color: var(--primary-color);
}

.review-content .btn {
    display: block;
    margin: 0 auto;
}

/* Responsive Design */
@media (max-width: 768px) {
    .welcome-content,
    #quizScreen,
    .results-content,
    .review-content {
        padding: 30px 20px;
    }

    .welcome-content h1 {
        font-size: 2rem;
    }

    .question-text {
        font-size: 1.2rem;
    }

    .quiz-stats {
        flex-direction: column;
    }

    .results-stats {
        grid-template-columns: 1fr;
    }

    .results-actions {
        flex-direction: column;
    }

    .results-actions .btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .quiz-info {
        grid-template-columns: 1fr;
    }

    .answer-btn {
        padding: 15px;
        font-size: 1rem;
    }

    .btn {
        width: 100%;
    }
}