:root {
    --nice-primary: #0066cc;
    --nice-secondary: #f8f9fa;
    --nice-correct: #28a745;
    --nice-incorrect: #dc3545;
    --nice-selected: #007bff;
    --nice-unselected: #6c757d;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f5f5;
    height: 100vh;
    overflow-x: hidden;
}

.nice-header {
    background-color: var(--nice-primary);
    color: white;
    padding: 0.75rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.question-container {
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    margin: 1rem 0;
    min-height: calc(100vh - 200px);
}

.question-header {
    background-color: var(--nice-secondary);
    border-bottom: 1px solid #dee2e6;
    padding: 1rem;
    border-radius: 8px 8px 0 0;
}

.question-content {
    padding: 2rem;
    line-height: 1.6;
}

.answer-option {
    border: 2px solid #e9ecef;
    border-radius: 8px;
    padding: 1rem;
    margin: 0.75rem 0;
    cursor: pointer;
    transition: all 0.3s ease;
    background: white;
}

.answer-option:hover {
    border-color: var(--nice-selected);
    background-color: #f8f9ff;
}

.answer-option.selected {
    border-color: var(--nice-selected);
    background-color: #e3f2fd;
    box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.25);
}

.answer-option.correct {
    border-color: var(--nice-correct);
    background-color: #d4edda;
}

.answer-option.incorrect {
    border-color: var(--nice-incorrect);
    background-color: #f8d7da;
}

.answer-option.unselected {
    opacity: 0.7;
    border-color: var(--nice-unselected);
}

.answer-label {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background-color: #6c757d;
    color: white;
    font-weight: bold;
    margin-right: 1rem;
    flex-shrink: 0;
}

.selected .answer-label {
    background-color: var(--nice-selected);
}

.correct .answer-label {
    background-color: var(--nice-correct);
}

.incorrect .answer-label {
    background-color: var(--nice-incorrect);
}

.explanation-panel {
    background-color: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 8px;
    padding: 1.5rem;
    margin-top: 2rem;
    display: none;
}

.explanation-panel.show {
    display: block;
    animation: slideDown 0.3s ease;
}

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

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

.control-panel {
    background: white;
    border-top: 1px solid #dee2e6;
    padding: 1rem;
    position: sticky;
    bottom: 0;
    box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.1);
}

.difficulty-badge {
    font-size: 0.8rem;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
}

.difficulty-easy {
    background-color: #d4edda;
    color: #155724;
}

.difficulty-medium {
    background-color: #fff3cd;
    color: #856404;
}

.difficulty-hard {
    background-color: #f8d7da;
    color: #721c24;
}

.question-tools {
    position: absolute;
    top: 1rem;
    right: 1rem;
}

.tool-btn {
    background: none;
    border: 1px solid #dee2e6;
    border-radius: 4px;
    padding: 0.5rem;
    margin-left: 0.5rem;
    cursor: pointer;
    color: #6c757d;
    transition: all 0.2s ease;
}

.tool-btn:hover {
    background-color: #f8f9fa;
    color: var(--nice-primary);
}

.progress-indicator {
    height: 4px;
    background-color: #e9ecef;
    border-radius: 2px;
    overflow: hidden;
}

.progress-bar-custom {
    height: 100%;
    background-color: var(--nice-primary);
    transition: width 0.3s ease;
}

@media (max-width: 768px) {
    .question-content {
        padding: 1rem;
    }

    .answer-option {
        padding: 0.75rem;
    }

    .control-panel {
        padding: 0.75rem;
    }
}

.answer-input {
    width: 100%; /* Adjust as needed */
    padding: 12px 15px; /* Similar padding to answer options */
    margin-bottom: 20px; /* Space below the input */
    border: 1px solid #555; /* Subtle border */
    border-radius: 8px; /* Rounded corners */
    font-size: 1.1em; /* Font size, similar to the options */
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.2); /* Inner shadow for depth */
    transition: border-color 0.3s ease, box-shadow 0.3s ease; /* Smooth transitions */
}

.submit-button {
    cursor: pointer;
}

/* Base styling for all navigation buttons/links */
.nav-button {
    text-decoration: none; /* Remove underline from links */
    color: white; /* White text color */
    padding: 8px 20px; /* Padding inside the buttons */
    border-radius: 25px; /* Makes the buttons pill-shaped */
    transition: background-color 0.3s ease, color 0.3s ease; /* Smooth transition for hover/active states */
}

/* Styling for the active (selected) button */
.nav-button.active {
    background-color: white; /* White background for the active button */
    color: #007bff; /* Blue text color for the active button */
    font-weight: bold; /* Make active text bold */
}

/* Hover effect for inactive buttons */
.nav-button:not(.active):hover {
    background-color: rgba(255, 255, 255, 0.2); /* Subtle white background on hover for inactive buttons */
}