:root {
    /* Color Palette */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --success-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --error-gradient: linear-gradient(135deg, #fa709a 0%, #fee140 100%);

    --bg-dark: #0f0e17;
    --bg-secondary: #1a1825;
    --surface: rgba(255, 255, 255, 0.05);
    --surface-hover: rgba(255, 255, 255, 0.1);

    --text-primary: #fffffe;
    --text-secondary: #a7a9be;
    --text-hint: #6e7191;

    --accent-purple: #667eea;
    --accent-pink: #f093fb;
    --accent-blue: #4facfe;
    --accent-green: #00f2fe;

    --success: #00f2aa;
    --error: #ff6b9d;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 40px rgba(102, 126, 234, 0.3);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* Animated Background */
.background-gradient {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(circle at 20% 50%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(240, 147, 251, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(79, 172, 254, 0.1) 0%, transparent 50%);
    z-index: -1;
    animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.8;
    }
}

/* Screen Management */
.screen {
    display: none;
    min-height: 100vh;
    padding: var(--spacing-sm);
    animation: fadeIn 0.4s ease;
    overflow-y: auto;
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.container {
    max-width: 700px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

/* Header */
.app-header {
    text-align: center;
    margin-bottom: var(--spacing-md);
    animation: slideDown 0.6s ease;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.app-title {
    font-family: 'Outfit', sans-serif;
    font-size: 2rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-xs);
    letter-spacing: -0.02em;
}

.app-subtitle {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 300;
}

/* Glass Card */
.glass-card {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-normal);
}

.glass-card:hover {
    border-color: rgba(255, 255, 255, 0.2);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    transform: translateY(-2px);
}

/* Form Elements */
.section-title {
    font-family: 'Outfit', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-weight: 600;
    font-size: 1rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.label-icon {
    font-size: 1.25rem;
}

.form-input {
    width: 100%;
    padding: 0.875rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    transition: all var(--transition-fast);
}

.form-input:focus {
    outline: none;
    border-color: var(--accent-purple);
    background: rgba(255, 255, 255, 0.08);
    box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1);
}

.form-input:hover {
    border-color: rgba(255, 255, 255, 0.2);
}

/* Range Inputs */
.range-inputs {
    display: flex;
    align-items: flex-end;
    gap: var(--spacing-md);
}

.input-wrapper {
    flex: 1;
}

.input-label {
    display: block;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
}

.range-separator {
    font-size: 1.5rem;
    color: var(--text-secondary);
    margin-bottom: 0.875rem;
}

.input-hint {
    font-size: 0.875rem;
    color: var(--text-hint);
    margin-top: var(--spacing-xs);
}

/* Radio Buttons */
.radio-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.radio-option {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 1rem;
    background: rgba(255, 255, 255, 0.03);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.radio-option::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.radio-option:hover {
    border-color: rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.05);
}

.radio-option input[type="radio"] {
    display: none;
}

.radio-custom {
    width: 20px;
    height: 20px;
    border: 2px solid var(--text-secondary);
    border-radius: 50%;
    position: relative;
    flex-shrink: 0;
    transition: all var(--transition-fast);
    z-index: 1;
}

.radio-custom::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0);
    width: 10px;
    height: 10px;
    background: var(--accent-purple);
    border-radius: 50%;
    transition: transform var(--transition-fast);
}

.radio-option input[type="radio"]:checked+.radio-custom {
    border-color: var(--accent-purple);
}

.radio-option input[type="radio"]:checked+.radio-custom::after {
    transform: translate(-50%, -50%) scale(1);
}

.radio-option input[type="radio"]:checked~.radio-label {
    color: var(--text-primary);
    font-weight: 600;
}

.radio-option:has(input[type="radio"]:checked) {
    border-color: var(--accent-purple);
    background: rgba(102, 126, 234, 0.1);
}

.radio-label {
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    z-index: 1;
}

/* Toggle Switch */
.toggle-option {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    cursor: pointer;
    padding: 1rem;
    background: rgba(255, 255, 255, 0.03);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.toggle-option:hover {
    border-color: rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.05);
}

.toggle-option input[type="checkbox"] {
    display: none;
}

.toggle-switch {
    width: 50px;
    height: 28px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 14px;
    position: relative;
    transition: all var(--transition-fast);
}

.toggle-switch::after {
    content: '';
    position: absolute;
    top: 3px;
    left: 3px;
    width: 22px;
    height: 22px;
    background: var(--text-secondary);
    border-radius: 50%;
    transition: all var(--transition-fast);
}

.toggle-option input[type="checkbox"]:checked+.toggle-switch {
    background: var(--accent-purple);
}

.toggle-option input[type="checkbox"]:checked+.toggle-switch::after {
    left: 25px;
    background: white;
}

.toggle-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-secondary);
    font-weight: 500;
    transition: color var(--transition-fast);
}

.toggle-option:has(input[type="checkbox"]:checked) .toggle-label {
    color: var(--text-primary);
}

/* Timer Settings */
.timer-settings {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.02);
    border-radius: var(--radius-md);
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        max-height: 0;
    }

    to {
        opacity: 1;
        max-height: 200px;
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 0.875rem 1.75rem;
    border: none;
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:active::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--primary-gradient);
    color: white;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.5);
    transform: translateY(-2px);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    border: 2px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.btn-large {
    width: 100%;
    padding: 1.125rem 2rem;
    font-size: 1.125rem;
}

.btn-arrow {
    font-size: 1.25rem;
    transition: transform var(--transition-fast);
}

.btn:hover .btn-arrow {
    transform: translateX(4px);
}

/* Error Message */
.error-message {
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 107, 157, 0.1);
    border: 2px solid var(--error);
    border-radius: var(--radius-md);
    color: var(--error);
    margin-bottom: var(--spacing-md);
    animation: shake 0.5s ease;
}

@keyframes shake {

    0%,
    100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-10px);
    }

    75% {
        transform: translateX(10px);
    }
}

/* Quiz Screen */
.quiz-header {
    margin-bottom: var(--spacing-md);
}

.progress-bar {
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    height: 32px;
    position: relative;
    overflow: hidden;
    margin-bottom: var(--spacing-sm);
}

.progress-fill {
    height: 100%;
    background: var(--primary-gradient);
    border-radius: var(--radius-lg);
    transition: width 0.4s ease;
    position: relative;
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% {
        transform: translateX(-100%);
    }

    100% {
        transform: translateX(100%);
    }
}

.progress-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-weight: 600;
    color: var(--text-primary);
    z-index: 1;
}

.quiz-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md);
}

.timer {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1.125rem;
}

.timer-icon {
    font-size: 1.25rem;
}

.score-display {
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    font-weight: 600;
}

.score-label {
    color: var(--text-secondary);
    margin-right: var(--spacing-xs);
}

#score-value {
    color: var(--accent-blue);
    font-size: 1.25rem;
}

/* Question Card */
.question-card {
    animation: scaleIn 0.4s ease;
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }

    to {
        opacity: 1;
        transform: scale(1);
    }
}

.question-type-badge {
    display: inline-block;
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--success-gradient);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.question-header-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.speak-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-md);
    padding: var(--spacing-xs) var(--spacing-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-primary);
}

.speak-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: var(--accent-blue);
    transform: scale(1.05);
}

.speak-btn:active {
    transform: scale(0.95);
}

.speaker-icon {
    font-size: 1.25rem;
}

.question-actions {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.btn-action {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-action:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.3);
    color: var(--text-primary);
}

.btn-skip:hover {
    border-color: var(--accent-blue);
}

.btn-reveal:hover {
    border-color: var(--accent-pink);
}

.question-text {
    font-family: 'Outfit', sans-serif;
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    line-height: 1.3;
}

/* MCQ Options */
.mcq-options {
    display: grid;
    gap: var(--spacing-md);
}

.mcq-option {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.03);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
    font-size: 1rem;
    color: var(--text-primary);
}

.mcq-option:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateX(4px);
}

.option-letter {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    font-weight: 700;
    flex-shrink: 0;
}

.option-text {
    flex: 1;
}

.mcq-option.correct {
    background: rgba(0, 242, 170, 0.1);
    border-color: var(--success);
    animation: correctPulse 0.5s ease;
}

.mcq-option.incorrect {
    background: rgba(255, 107, 157, 0.1);
    border-color: var(--error);
    animation: incorrectShake 0.5s ease;
}

.mcq-option.disabled {
    pointer-events: none;
    opacity: 0.5;
}

@keyframes correctPulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.02);
    }
}

@keyframes incorrectShake {

    0%,
    100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-8px);
    }

    75% {
        transform: translateX(8px);
    }
}

/* Typing Input */
.typing-input {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.answer-input {
    width: 100%;
    padding: 1rem 1.25rem;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1.125rem;
    font-family: inherit;
    transition: all var(--transition-fast);
}

.answer-input:focus {
    outline: none;
    border-color: var(--accent-purple);
    background: rgba(255, 255, 255, 0.08);
    box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1);
}

/* Feedback */
.feedback {
    text-align: center;
    animation: fadeIn 0.3s ease;
}

.feedback-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
}

.feedback.correct .feedback-icon::before {
    content: '✅';
}

.feedback.incorrect .feedback-icon::before {
    content: '❌';
}

.feedback-message {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-lg);
    font-weight: 600;
}

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

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

/* Results Screen */
.results-card {
    text-align: center;
    animation: scaleIn 0.5s ease;
}

.results-icon {
    font-size: 5rem;
    margin-bottom: var(--spacing-md);
}

.results-title {
    font-family: 'Outfit', sans-serif;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: var(--spacing-xl);
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.results-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.stat-item {
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-md);
    border: 2px solid rgba(255, 255, 255, 0.1);
}

.stat-value {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--success-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.results-actions {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

/* Responsive Design */
@media (max-width: 768px) {
    .app-title {
        font-size: 2rem;
    }

    .app-subtitle {
        font-size: 1rem;
    }

    .glass-card {
        padding: var(--spacing-lg);
    }

    .range-inputs {
        flex-direction: column;
        align-items: stretch;
    }

    .range-separator {
        display: none;
    }

    .question-text {
        font-size: 1.5rem;
    }

    .results-title {
        font-size: 2rem;
    }

    .stat-value {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .screen {
        padding: var(--spacing-md);
    }

    .app-title {
        font-size: 1.75rem;
    }

    .glass-card {
        padding: var(--spacing-md);
    }

    .question-text {
        font-size: 1.25rem;
    }
}