/* Base Styles */
:root {
    --primary-color: #3498db;
    --primary-dark: #2980b9;
    --success-color: #2ecc71;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    --light-bg: #f5f7fa;
    --dark-bg: #2c3e50;
    --light-text: #333333;
    --dark-text: #ecf0f1;
    --card-bg: #ffffff;
    --card-bg-dark: #34495e;
    --border-radius: 10px;
    --box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    --box-shadow-dark: 0 4px 15px rgba(0, 0, 0, 0.3);
    --transition: all 0.3s ease;
    --mastery-color: #27ae60;
    --mastery-color-dark: #219955;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--light-bg);
    color: var(--light-text);
    line-height: 1.6;
    transition: var(--transition);
}

body.dark-mode {
    background-color: var(--dark-bg);
    color: var(--dark-text);
}

.app-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles */
header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px 0;
    border-bottom: 2px solid var(--primary-color);
}

header h1 {
    color: var(--primary-color);
    font-size: 2.5rem;
    margin-bottom: 5px;
}

.tagline {
    color: #7f8c8d;
    font-size: 1.1rem;
}

.dark-mode .tagline {
    color: #bdc3c7;
}

/* Main Content */
main {
    flex: 1;
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 25px;
    transition: var(--transition);
}

.dark-mode main {
    background-color: var(--card-bg-dark);
    box-shadow: var(--box-shadow-dark);
}

/* Screen Styles */
.screen {
    display: none;
    animation: fadeIn 0.3s ease;
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* Welcome Screen */
#welcome-screen {
    text-align: center;
    padding: 40px 20px;
}

#welcome-screen h2 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.file-upload {
    margin-top: 30px;
    padding: 20px;
    border: 2px dashed #e0e0e0;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.dark-mode .file-upload {
    border-color: #546e7a;
}

.file-upload p {
    margin-bottom: 15px;
    color: #7f8c8d;
}

.dark-mode .file-upload p {
    color: #bdc3c7;
}

input[type="file"] {
    display: block;
    margin: 15px auto;
    color: #7f8c8d;
    background-color: transparent;
    border: 1px solid #e0e0e0;
    padding: 10px;
    border-radius: 5px;
    width: 100%;
    max-width: 300px;
}

.dark-mode input[type="file"] {
    color: #bdc3c7;
    border-color: #546e7a;
}

.sample-buttons {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.format-info {
    background-color: #f8f9fa;
    padding: 15px;
    border-radius: var(--border-radius);
    margin-top: 20px;
    text-align: left;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.dark-mode .format-info {
    background-color: #3d4b5c;
}

.format-tabs {
    display: flex;
    gap: 10px;
    margin: 10px 0;
}

.format-tab {
    background-color: #e9ecef;
    color: #495057;
    border: none;
    padding: 8px 15px;
    border-radius: 5px;
    cursor: pointer;
    transition: var(--transition);
}

.dark-mode .format-tab {
    background-color: #455a64;
    color: #ecf0f1;
}

.format-tab.active {
    background-color: var(--primary-color);
    color: white;
}

.format-content {
    display: none;
    padding: 10px;
    background-color: white;
    border-radius: 5px;
    border: 1px solid #e0e0e0;
}

.dark-mode .format-content {
    background-color: #2c3e50;
    border-color: #546e7a;
}

.format-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

.format-content code {
    display: block;
    padding: 10px;
    background-color: #f1f3f5;
    border-radius: 5px;
    margin-bottom: 10px;
    overflow-x: auto;
    font-family: 'Courier New', Courier, monospace;
}

.dark-mode .format-content code {
    background-color: #1e2a38;
}

button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

button:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.dark-mode button {
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
}

.dark-mode button:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.4);
}

/* Settings Screen */
#settings-screen {
    padding: 20px;
}

#settings-screen h2 {
    text-align: center;
    font-size: 1.8rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

#settings-screen p {
    text-align: center;
    margin-bottom: 25px;
    color: #7f8c8d;
}

.dark-mode #settings-screen p {
    color: #bdc3c7;
}

.category-time-setting {
    display: flex;
    align-items: center;
    margin-bottom: 15px;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
}

.dark-mode .category-time-setting {
    background-color: #3d4b5c;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.category-time-setting:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.dark-mode .category-time-setting:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

.category-name {
    flex: 2;
    font-weight: 500;
    text-transform: capitalize;
}

.category-time-input {
    flex: 1;
    padding: 10px 12px;
    border: 2px solid #e0e0e0;
    border-radius: 5px;
    font-size: 1rem;
    text-align: center;
    transition: var(--transition);
}

.dark-mode .category-time-input {
    background-color: #2c3e50;
    border-color: #546e7a;
    color: white;
}

.category-time-input:focus {
    border-color: var(--primary-color);
    outline: none;
    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
}

.dark-mode .category-time-input:focus {
    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.4);
}

.seconds-label {
    margin-left: 10px;
    color: #7f8c8d;
}

.dark-mode .seconds-label {
    color: #bdc3c7;
}

#start-study {
    display: block;
    margin: 30px auto 0;
    width: 200px;
}

/* Study Screen */
.progress-container {
    margin-bottom: 25px;
}

.progress-info {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    margin-bottom: 10px;
    font-weight: 500;
}

.progress-info span {
    margin: 5px;
}

#mastery-indicator {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 5px;
    min-width: 120px;
}

.mastery-progress {
    width: 100%;
    height: 6px;
    background-color: #ecf0f1;
    border-radius: 3px;
    overflow: hidden;
    margin-top: 5px;
}

.dark-mode .mastery-progress {
    background-color: #455a64;
}

.mastery-progress-fill {
    height: 100%;
    width: 0%;
    background-color: var(--success-color);
    transition: width 0.5s ease;
}

.progress-bar {
    height: 10px;
    background-color: #ecf0f1;
    border-radius: 5px;
    overflow: hidden;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.1);
}

.dark-mode .progress-bar {
    background-color: #455a64;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.3);
}

#progress-fill {
    height: 100%;
    background-color: var(--primary-color);
    width: 0%;
    transition: width 0.3s ease;
}

.question-container {
    background-color: #f8f9fa;
    padding: 25px;
    border-radius: var(--border-radius);
    margin-bottom: 25px;
    position: relative;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
}

.dark-mode .question-container {
    background-color: #3d4b5c;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

#timer {
    position: absolute;
    top: 15px;
    right: 15px;
    background-color: var(--primary-color);
    color: white;
    padding: 8px 12px;
    border-radius: 15px;
    font-weight: bold;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.dark-mode #timer {
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
}

#target-time {
    position: absolute;
    top: 15px;
    left: 15px;
    background-color: var(--success-color);
    color: white;
    padding: 8px 12px;
    border-radius: 15px;
    font-weight: bold;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.dark-mode #target-time {
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
}

/* Mastery Badge */
#mastery-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background-color: var(--mastery-color);
    color: white;
    padding: 5px 10px;
    border-radius: 15px;
    font-weight: bold;
    display: flex;
    align-items: center;
    gap: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    animation: badgePulse 2s infinite;
    z-index: 10;
}

.hidden {
    display: none !important;
}

@keyframes badgePulse {
    0% { transform: scale(1); box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2); }
    50% { transform: scale(1.05); box-shadow: 0 3px 8px rgba(0, 0, 0, 0.3); }
    100% { transform: scale(1); box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2); }
}

.badge-icon {
    font-size: 1.2rem;
}

.badge-text {
    font-size: 0.8rem;
    letter-spacing: 1px;
}

#difficulty-display {
    color: var(--warning-color);
    font-weight: bold;
}

#question-display {
    font-size: 1.5rem;
    margin: 30px 0;
    text-align: center;
    min-height: 60px;
    padding: 20px;
    border-radius: var(--border-radius);
    background-color: white;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    line-height: 1.6;
}

.dark-mode #question-display {
    background-color: #2c3e50;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

/* UPDATED: Math Input Container and Preview */
.math-input-container {
    position: relative;
    margin-bottom: 20px;
    border: 2px solid #e0e0e0;
    border-radius: 5px;
    transition: all 0.3s ease;
    background-color: white;
}

.dark-mode .math-input-container {
    background-color: #2c3e50;
    border-color: #546e7a;
}

.math-input-container.focused {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

.dark-mode .math-input-container.focused {
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.4);
}

.math-preview {
    padding: 16px 15px;
    min-height: 120px;
    font-size: 1.1rem;
    line-height: 1.5;
    white-space: pre-wrap;
    word-wrap: break-word;
    color: #333;
    pointer-events: none;
}

.dark-mode .math-preview {
    color: #fff;
}

.math-input {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    padding: 16px 15px;
    font-size: 1.1rem;
    line-height: 1.5;
    background-color: transparent;
    border: none;
    outline: none;
    color: transparent;
    caret-color: #333;
    resize: none;
    overflow: hidden;
    white-space: pre-wrap;
    word-wrap: break-word;
    z-index: 2;
}

.dark-mode .math-input {
    caret-color: #fff;
}

.math-input::placeholder {
    color: #999;
}

.dark-mode .math-input::placeholder {
    color: #777;
}

/* Display placeholder only when input is empty */
.math-input-container.has-content .math-input::placeholder {
    color: transparent;
}

/* Math Display Styles (Desmos-like) */
.fraction {
    display: inline-block;
    vertical-align: middle;
    text-align: center;
    font-size: 1em;
    margin: 0 2px;
    line-height: 1.3;
}

.fraction .numerator {
    display: block;
    padding: 0 3px;
    border-bottom: 1px solid;
    margin-bottom: 1px;
}

.fraction .denominator {
    display: block;
    padding: 0 3px;
}

.power {
    display: inline-block;
    vertical-align: super;
    font-size: 0.7em;
    margin-left: 2px;
}

.sqrt-content {
    display: inline-block;
    padding-top: 1px;
    border-top: 1px solid;
}

.paren-open, .paren-close {
    color: inherit;
}

/* Display placeholder only when input is empty */
.math-input-container.has-content .math-input::placeholder {
    color: transparent;
}

/* Ensure preview and input are perfectly aligned */
.math-preview, .math-input {
    font-family: 'Arial', sans-serif;
    letter-spacing: normal;
}

/* Multiple choice styles */
#mcq-container {
    margin-bottom: 15px;
}

.mcq-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 12px;
    margin-bottom: 16px;
}

@media (max-width: 600px) {
    .mcq-options {
        grid-template-columns: 1fr;
    }
}

.mcq-option {
    padding: 15px;
    background-color: white;
    border: 2px solid #e0e0e0;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 60px;
}

.dark-mode .mcq-option {
    background-color: #2c3e50;
    border-color: #546e7a;
}

.mcq-option:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    border-color: var(--primary-color);
}

.dark-mode .mcq-option:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

.mcq-option.selected {
    background-color: rgba(52, 152, 219, 0.1);
    border-color: var(--primary-color);
    font-weight: bold;
}

.dark-mode .mcq-option.selected {
    background-color: rgba(52, 152, 219, 0.3);
}

#submit-answer {
    width: 100%;
}

.stats-container {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
}

.stat-box {
    flex: 1;
    min-width: 100px;
    text-align: center;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
    margin: 0 5px 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
}

.dark-mode .stat-box {
    background-color: #3d4b5c;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.stat-label {
    display: block;
    color: #7f8c8d;
    margin-bottom: 5px;
}

.dark-mode .stat-label {
    color: #bdc3c7;
}

.stat-value {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--primary-color);
}

/* Category Mastery Overview */
.mastery-overview {
    margin-top: 20px;
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
    padding: 15px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.dark-mode .mastery-overview {
    background-color: #3d4b5c;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.mastery-overview h3 {
    text-align: center;
    margin-bottom: 15px;
    color: var(--primary-dark);
}

.dark-mode .mastery-overview h3 {
    color: #ecf0f1;
}

#category-mastery-overview {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.category-mastery-item {
    flex: 1;
    min-width: 120px;
    padding: 10px;
    background-color: white;
    border-radius: var(--border-radius);
    text-align: center;
    position: relative;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
    cursor: pointer; /* Make it appear clickable */
    border: 2px solid transparent; /* For selected state */
}

.dark-mode .category-mastery-item {
    background-color: #2c3e50;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.category-mastery-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.dark-mode .category-mastery-item:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

/* Selected state for category items */
.category-mastery-item.selected {
    background-color: rgba(52, 152, 219, 0.2); /* Light blue background */
    border-color: var(--primary-color);
}

.dark-mode .category-mastery-item.selected {
    background-color: rgba(52, 152, 219, 0.3);
}

.progress-info span {
    margin: 5px;
}

/* Clickable category button styling */
.clickable {
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.clickable:hover {
    transform: translateY(-2px);
}

.category-button {
    background-color: var(--primary-color);
    color: white;
    padding: 6px 12px;
    border-radius: 4px;
    display: inline-block;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: all 0.2s ease;
}

.clickable:hover .category-button {
    background-color: var(--primary-dark);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.dark-mode .category-button {
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.dark-mode .clickable:hover .category-button {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.4);
}
.no-question-message {
    background-color: rgba(231, 76, 60, 0.1);
    border: 2px dashed #e74c3c;
    padding: 20px;
    border-radius: var(--border-radius);
    text-align: center;
    color: #e74c3c;
    font-weight: bold;
    margin: 20px 0;
}

.dark-mode .no-question-message {
    background-color: rgba(231, 76, 60, 0.2);
}

/* Select All button styling */
.select-all-item {
    background-color: #f8f9fa;
    border: 1px dashed #ccc;
    display: flex;
    justify-content: center;
    align-items: center;
    min-width: 100%; /* Make it full width */
    margin-bottom: 10px;
}

.dark-mode .select-all-item {
    background-color: #3d4b5c;
    border-color: #546e7a;
}

.select-all-item .category-mastery-name {
    font-weight: bold;
    color: var(--primary-color);
}

/* "No categories selected" message */
.no-categories-selected {
    background-color: rgba(231, 76, 60, 0.1);
    border: 2px dashed #e74c3c;
    padding: 15px;
    border-radius: var(--border-radius);
    text-align: center;
    margin-bottom: 15px;
    width: 100%;
}

.dark-mode .no-categories-selected {
    background-color: rgba(231, 76, 60, 0.2);
}

.no-categories-selected p {
    color: #e74c3c;
    font-weight: bold;
    margin: 0;
}

.category-question-count {
    font-size: 0.8rem;
    color: #7f8c8d;
    margin-bottom: 5px;
}

.dark-mode .category-question-count {
    color: #bdc3c7;
}

.category-mastery-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--primary-color);
    opacity: 0;
    border-radius: var(--border-radius);
    transition: opacity 0.2s ease;
    pointer-events: none;
}

.category-mastery-item:active::before {
    opacity: 0.1;
}

/* End of session dialog */
.end-session-dialog {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    animation: fadeIn 0.3s ease;
}

.end-session-content {
    background-color: var(--card-bg);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    width: 80%;
    max-width: 500px;
    text-align: center;
    animation: slideDown 0.3s ease;
}

.dark-mode .end-session-content {
    background-color: var(--card-bg-dark);
    box-shadow: var(--box-shadow-dark);
}

.end-session-content h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
}

.end-session-content p {
    margin-bottom: 20px;
}

.end-session-content button {
    margin: 10px;
    min-width: 180px;
    padding: 12px 20px;
}

.analyze-btn {
    background-color: var(--primary-color);
}

.new-categories-btn {
    background-color: var(--success-color);
}



.category-mastery-name {
    font-weight: 500;
    text-transform: capitalize;
    margin-bottom: 5px;
}

.category-mastery-bar {
    height: 6px;
    background-color: #ecf0f1;
    border-radius: 3px;
    overflow: hidden;
    margin: 10px 0;
}

.dark-mode .category-mastery-bar {
    background-color: #455a64;
}

.category-mastery-fill {
    height: 100%;
    width: 0%;
    background-color: var(--primary-color);
    transition: width 0.5s ease;
}

.category-mastery-fill.mastered {
    background-color: var(--mastery-color);
}

.category-mastery-value {
    font-size: 0.9rem;
    color: #7f8c8d;
}

.dark-mode .category-mastery-value {
    color: #bdc3c7;
}

.category-badge {
    position: absolute;
    top: -8px;
    right: -8px;
    background-color: var(--mastery-color);
    color: white;
    font-size: 0.7rem;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

/* Feedback Screen */
#feedback-screen {
    text-align: center;
    padding: 30px;
}

#answer-feedback, #time-feedback, #time-score-feedback {
    font-size: 1.3rem;
    margin-bottom: 15px;
    padding: 15px;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.dark-mode #answer-feedback, 
.dark-mode #time-feedback, 
.dark-mode #time-score-feedback {
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

#answer-feedback.correct {
    background-color: rgba(46, 204, 113, 0.2);
    color: var(--success-color);
    border-left: 4px solid var(--success-color);
}

#answer-feedback.incorrect {
    background-color: rgba(231, 76, 60, 0.2);
    color: var(--danger-color);
    border-left: 4px solid var(--danger-color);
}

#time-feedback, #time-score-feedback {
    color: #7f8c8d;
}

.dark-mode #time-feedback, 
.dark-mode #time-score-feedback {
    color: #bdc3c7;
}

#time-score-feedback.good {
    background-color: rgba(46, 204, 113, 0.2);
    color: var(--success-color);
    border-left: 4px solid var(--success-color);
}

#time-score-feedback.average {
    background-color: rgba(243, 156, 18, 0.2);
    color: var(--warning-color);
    border-left: 4px solid var(--warning-color);
}

#time-score-feedback.poor {
    background-color: rgba(231, 76, 60, 0.2);
    color: var(--danger-color);
    border-left: 4px solid var(--danger-color);
}

/* Improved Feedback Actions */
.feedback-actions {
    display: flex;
    justify-content: center;
    margin: 20px 0;
}

#see-explanation {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    font-weight: 500;
    transition: all 0.2s ease;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

#see-explanation:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

#see-explanation:disabled {
    background-color: #95a5a6;
    transform: none;
    box-shadow: none;
}

/* Improved Explanation Container */
#explanation-container {
    background-color: #f8f9fa;
    border-radius: 10px;
    padding: 20px;
    margin: 20px 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    max-height: 600px; /* Increased height */
    overflow-y: auto;
    border-left: 4px solid var(--primary-color);
    text-align: left;
}

.dark-mode #explanation-container {
    background-color: #3d4b5c;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.explanation-loading {
    text-align: center;
    padding: 20px;
    color: #7f8c8d;
}

.dark-mode .explanation-loading {
    color: #bdc3c7;
}

#explanation-content {
    font-size: 1rem;
    line-height: 1.7;
}

/* Support for Markdown Bold/Italic in explanations */
#explanation-content .bold {
    font-weight: bold;
}

#explanation-content .italic {
    font-style: italic;
}

#explanation-content .underline {
    text-decoration: underline;
}

#explanation-content h2 {
    color: var(--primary-color);
    font-size: 1.4rem;
    margin-bottom: 15px;
    border-bottom: 1px solid #e0e0e0;
    padding-bottom: 8px;
}

.dark-mode #explanation-content h2 {
    border-bottom-color: #546e7a;
}

#explanation-content h3 {
    color: #2c3e50;
    font-size: 1.2rem;
    margin: 18px 0 10px;
    font-weight: 600;
}

.dark-mode #explanation-content h3 {
    color: #ecf0f1;
}

#explanation-content p {
    margin-bottom: 12px;
}

#explanation-content ul, #explanation-content ol {
    margin: 15px 0;
    padding-left: 25px;
}

#explanation-content li {
    margin-bottom: 8px;
}

#explanation-content code {
    background-color: #f0f0f0;
    padding: 2px 5px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

.dark-mode #explanation-content code {
    background-color: #2c3e50;
}

#explanation-content blockquote {
    border-left: 3px solid var(--primary-color);
    padding-left: 15px;
    margin: 15px 0;
    color: #555;
    font-style: italic;
}

.dark-mode #explanation-content blockquote {
    color: #bbb;
}

/* Math in explanations */
#explanation-content .katex {
    font-size: 1.1em;
}

#explanation-content .math-block {
    display: block;
    text-align: center;
    padding: 10px;
    margin: 15px 0;
    overflow-x: auto;
}

/* Step by step solutions */
.solution-step {
    padding: 10px;
    margin: 8px 0;
    border-left: 3px solid var(--primary-color);
    background-color: rgba(52, 152, 219, 0.05);
    border-radius: 0 5px 5px 0;
}

.dark-mode .solution-step {
    background-color: rgba(52, 152, 219, 0.1);
}

/* Highlights for key concepts */
.key-concept {
    background-color: rgba(46, 204, 113, 0.1);
    padding: 10px 15px;
    margin: 15px 0;
    border-radius: 5px;
    border-left: 3px solid var(--success-color);
}

.dark-mode .key-concept {
    background-color: rgba(46, 204, 113, 0.15);
}

/* Mastery Feedback */
#mastery-feedback {
    margin: 20px 0;
    padding: 0;
    box-shadow: none;
}

.mastery-congrats {
    background-color: rgba(46, 204, 113, 0.1);
    border: 2px dashed var(--mastery-color);
    border-radius: var(--border-radius);
    padding: 20px;
    text-align: center;
    animation: fadeIn 0.5s ease;
}

.mastery-icon {
    font-size: 3rem;
    margin-bottom: 10px;
}

.mastery-congrats h3 {
    color: var(--mastery-color);
    margin-bottom: 10px;
}

.mastery-congrats p {
    color: #2c3e50;
}

.dark-mode .mastery-congrats p {
    color: #ecf0f1;
}

#next-question {
    margin-top: 20px;
}

/* Results Screen */
#results-screen {
    text-align: center;
    padding: 30px;
}

#results-screen h2 {
    color: var(--primary-color);
    margin-bottom: 25px;
}

#results-screen h3 {
    color: #2c3e50;
    margin: 25px 0 15px;
}

.dark-mode #results-screen h3 {
    color: #ecf0f1;
}

.results-summary, .category-result {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: var(--border-radius);
    margin-bottom: 25px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
}

.dark-mode .results-summary, 
.dark-mode .category-result {
    background-color: #3d4b5c;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.results-summary:hover, 
.category-result:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.dark-mode .results-summary:hover, 
.dark-mode .category-result:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.result-metric {
    margin: 15px 0;
}

.metric-label {
    font-weight: bold;
    margin-right: 10px;
}

.metric-value {
    color: var(--primary-color);
    font-size: 1.2rem;
}

.category-result {
    margin-bottom: 15px;
    text-align: left;
    position: relative;
}

.category-result h4 {
    text-transform: capitalize;
    margin-bottom: 10px;
    color: var(--primary-color);
    display: flex;
    align-items: center;
}

.category-result.mastered h4::after {
    content: "✓";
    display: inline-block;
    margin-left: 10px;
    color: var(--mastery-color);
    font-weight: bold;
}

.category-mastery-bar {
    height: 20px;
    background-color: #ecf0f1;
    border-radius: 5px;
    overflow: hidden;
    margin: 10px 0;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.1);
}

.dark-mode .category-mastery-bar {
    background-color: #455a64;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.3);
}

.category-mastery-fill {
    height: 100%;
    transition: width 0.5s ease, background-color 0.5s ease;
}

.mastery-feedback {
    padding: 20px;
    border-radius: var(--border-radius);
    margin-bottom: 25px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.dark-mode .mastery-feedback {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.mastery-feedback.mastered {
    background-color: rgba(46, 204, 113, 0.2);
    color: var(--success-color);
    border-left: 4px solid var(--success-color);
}

.mastery-feedback.not-mastered {
    background-color: rgba(231, 76, 60, 0.2);
    color: var(--danger-color);
    border-left: 4px solid var(--danger-color);
}

#restart-btn {
    margin-top: 15px;
}

/* Footer */
footer {
    text-align: center;
    padding: 20px 0;
    color: #7f8c8d;
    margin-top: 20px;
}

.dark-mode footer {
    color: #bdc3c7;
}

/* Settings Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.5);
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background-color: var(--card-bg);
    margin: 15% auto;
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    width: 80%;
    max-width: 500px;
    position: relative;
    animation: slideDown 0.3s ease;
}

.dark-mode .modal-content {
    background-color: var(--card-bg-dark);
    box-shadow: var(--box-shadow-dark);
}

@keyframes slideDown {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.close {
    position: absolute;
    top: 10px;
    right: 20px;
    color: #aaa;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
}

.close:hover {
    color: var(--danger-color);
}

.modal h2 {
    text-align: center;
    font-size: 1.8rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.settings-group {
    margin-bottom: 20px;
    border-bottom: 1px solid #e0e0e0;
    padding-bottom: 15px;
}

.dark-mode .settings-group {
    border-bottom-color: #546e7a;
}

.settings-group:last-child {
    border-bottom: none;
    padding-bottom: 0;
    margin-bottom: 0;
}

.settings-group h3 {
    margin-bottom: 15px;
    color: #2c3e50;
}

.dark-mode .settings-group h3 {
    color: #ecf0f1;
}

.settings-option {
    padding: 10px 0 15px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.settings-option label {
    margin-bottom: 8px;
}

.switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
    margin-bottom: 8px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: var(--transition);
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: var(--transition);
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:focus + .slider {
    box-shadow: 0 0 1px var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}

.setting-description {
    margin-top: 6px;
    font-size: 0.9rem;
    color: #7f8c8d;
    width: 100%;
    line-height: 1.4;
}

.dark-mode .setting-description {
    color: #bdc3c7;
}

/* Replace your current "Fix settings modal positioning flicker" section with this */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: hidden; /* Prevent scrolling */
    background-color: rgba(0, 0, 0, 0.5);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.modal.show {
    opacity: 1;
}

/* Replace your modal-content styles with this */
.modal-content {
    background-color: var(--card-bg);
    padding: 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    width: 80%;
    max-width: 500px;
    max-height: 80vh; /* Add max height */
    overflow-y: auto; /* Allow scrolling if needed */
    
    /* Force center positioning */
    position: absolute !important;
    top: 50% !important;
    left: 50% !important;
    transform: translate(-50%, -50%) !important;
    margin: 0 !important; /* Override the 15% top margin */
    
    opacity: 0;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.dark-mode .modal-content {
    background-color: var(--card-bg-dark);
    box-shadow: var(--box-shadow-dark);
}

.modal.show .modal-content {
    transform: translate(-50%, -50%) scale(1);
    opacity: 1;
}

/* Remove slideDown animation as it conflicts with our positioning */
@keyframes slideDown {
    from {
        transform: translate(-50%, -50%) scale(0.95);
        opacity: 0;
    }
    to {
        transform: translate(-50%, -50%) scale(1);
        opacity: 1;
    }
}

/* Settings number input improvements */
.settings-number-input {
    padding: 8px 12px;
    border: 2px solid #e0e0e0;
    border-radius: 5px;
    font-size: 0.9rem;
    width: 80px;
    text-align: center;
    transition: all 0.3s ease;
}

.dark-mode .settings-number-input {
    background-color: #2c3e50;
    border-color: #546e7a;
    color: white;
}

.settings-number-input:focus {
    border-color: var(--primary-color);
    outline: none;
    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
}

/* Floating Settings Button */
.floating-btn {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    transition: var(--transition);
    z-index: 100;
}

.floating-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.3);
}

.dark-mode .floating-btn {
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.4);
}

.dark-mode .floating-btn:hover {
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.5);
}

/* KaTeX Styling */
.katex {
    font-size: 1.1em !important;
}

.katex-display {
    margin: 0.5em 0 !important;
}

/* Processing indicator animation */
.processing-indicator {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s linear infinite;
    margin-right: 8px;
    vertical-align: middle;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Disabled button style */
button:disabled {
    background-color: #7f8c8d;
    cursor: not-allowed;
    transform: none !important;
    box-shadow: none !important;
}

.dark-mode button:disabled {
    background-color: #546e7a;
}

/* Upload options styling */
.upload-options {
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 20px 0;
    flex-wrap: wrap;
    gap: 15px;
}

.upload-btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 12px 25px;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.upload-btn:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.dark-mode .upload-btn {
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
}

.dark-mode .upload-btn:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.4);
}

.upload-btn input[type="file"] {
    display: none;
}

.or-divider {
    font-weight: bold;
    color: #7f8c8d;
    margin: 0 10px;
}

.dark-mode .or-divider {
    color: #bdc3c7;
}

.preset-btn {
    background-color: #3498db;
    color: white;
}

/* Presets screen */
.screen-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    border-bottom: 1px solid #e0e0e0;
    padding-bottom: 15px;
}

.dark-mode .screen-header {
    border-bottom-color: #546e7a;
}

.back-btn {
    display: flex;
    align-items: center;
    padding: 8px 15px;
    font-size: 0.9rem;
    background-color: #f8f9fa;
    color: #333;
    border: 1px solid #e0e0e0;
}

.dark-mode .back-btn {
    background-color: #3d4b5c;
    color: #ecf0f1;
    border-color: #546e7a;
}

.back-arrow {
    margin-right: 5px;
    font-weight: bold;
}

.presets-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.preset-item {
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
    padding: 20px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.dark-mode .preset-item {
    background-color: #3d4b5c;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.preset-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.dark-mode .preset-item:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.preset-item h3 {
    color: var(--primary-color);
    margin-bottom: 10px;
    font-size: 1.2rem;
}

.preset-item p {
    color: #7f8c8d;
    margin-bottom: 15px;
    flex-grow: 1;
    font-size: 0.95rem;
}

.dark-mode .preset-item p {
    color: #bdc3c7;
}

.preset-select-btn {
    align-self: flex-end;
    padding: 8px 20px;
    font-size: 0.9rem;
    margin-top: auto;
}

.preset-loading {
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
    padding: 20px;
    text-align: center;
    grid-column: 1 / -1;
    color: #7f8c8d;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    animation: pulse 1.5s infinite ease-in-out;
}

.dark-mode .preset-loading {
    background-color: #3d4b5c;
    color: #bdc3c7;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.preset-empty {
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
    padding: 20px;
    text-align: center;
    grid-column: 1 / -1;
    color: #e74c3c;
}

.dark-mode .preset-empty {
    background-color: #3d4b5c;
    color: #e74c3c;
}

@keyframes pulse {
    0% { opacity: 0.6; }
    50% { opacity: 1; }
    100% { opacity: 0.6; }
}

/* Responsive styles for presets */
@media (max-width: 600px) {
    .presets-container {
        grid-template-columns: 1fr;
    }
    
    .upload-options {
        flex-direction: column;
        gap: 10px;
    }
    
    .or-divider {
        margin: 5px 0;
    }
    
    .screen-header {
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }
    
    .back-btn {
        align-self: flex-start;
    }
}

/* Responsive Styles */
@media (max-width: 768px) {
    .app-container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    main {
        padding: 15px;
    }
    
    .progress-info {
        flex-direction: column;
        align-items: center;
    }
    
    .progress-info span {
        margin-bottom: 5px;
    }
    
    .stats-container {
        flex-direction: column;
    }
    
    .stat-box {
        margin: 5px 0;
        width: 100%;
    }
    
    .category-time-setting {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .category-name {
        margin-bottom: 10px;
    }
    
    .category-time-input {
        width: 100%;
        margin-bottom: 10px;
    }
    
    .modal-content {
        width: 95%;
        margin: 10% auto;
        padding: 20px;
    }
    
    #question-display {
        font-size: 1.3rem;
        padding: 10px;
    }
    
    .settings-option {
        flex-direction: column;
        align-items: flex-start;
        padding: 15px 0;
    }
    
    .switch {
        margin-top: 10px;
    }

    /* Adjust math input for mobile */
    .math-input {
        min-height: 80px;
    }
}

/* Add these styles to your stylesheet for better answer formatting */

/* Formatted answer in incorrect feedback */
.formatted-answer {
    background-color: rgba(255, 255, 255, 0.9);
    padding: 12px 15px;
    border-radius: 6px;
    border: 1px solid #ddd;
    margin-top: 10px;
    font-size: 1rem;
    line-height: 1.5;
    text-align: left;
}

.dark-mode .formatted-answer {
    background-color: rgba(52, 73, 94, 0.9);
    border-color: #546e7a;
}

.formatted-answer p {
    margin-bottom: 8px;
}

.formatted-answer ul, .formatted-answer ol {
    margin: 8px 0;
    padding-left: 25px;
}

.formatted-answer li {
    margin-bottom: 4px;
}

/* Number formatting for multi-part answers */
.formatted-answer .part-number {
    font-weight: bold;
    color: var(--primary-color);
    margin-right: 8px;
}

/* Step formatting for multi-step solutions */
.formatted-answer .step {
    display: block;
    margin: 6px 0;
    border-left: 3px solid var(--primary-color);
    padding-left: 10px;
}

/* Math expression formatting */
.formatted-answer .math {
    font-family: 'Times New Roman', Times, serif;
    font-style: italic;
}

/* Variable highlighting in questions */
.variable {
    font-style: italic;
    color: var(--primary-dark);
}

.dark-mode .variable {
    color: #64b5f6;
}

/* Equation formatting in questions */
.question-equation {
    display: inline-block;
    margin: 0 3px;
    font-family: 'Times New Roman', Times, serif;
}

/* Feedback screen improvements */
#answer-feedback {
    text-align: left;
    padding: 18px;
}

#answer-feedback.incorrect {
    background-color: rgba(231, 76, 60, 0.1);
    color: var(--danger-color);
    border-left: 4px solid var(--danger-color);
}

#answer-feedback.incorrect > div:first-child {
    font-size: 1.3rem;
    margin-bottom: 12px;
    font-weight: 600;
}

/* Markdown-style text formatting */
.md-bold {
    font-weight: bold;
}

.md-italic {
    font-style: italic;
}

/* Add these styles to ensure proper display within questions */
#question-display .md-bold {
    font-weight: bold;
    color: inherit;
}

#question-display .md-italic {
    font-style: italic;
    color: inherit;
}

/* Additional formatting for answer feedback */
.formatted-answer .md-bold {
    font-weight: bold;
}

.formatted-answer .md-italic {
    font-style: italic;
}

.formatted-answer ul {
    padding-left: 20px;
    margin: 10px 0;
}

.formatted-answer li {
    margin-bottom: 5px;
    list-style-type: disc;
}

.dark-mode .formatted-answer .md-bold,
.dark-mode .formatted-answer .md-italic {
    color: inherit;
}

/* Add these styles to your styles.css file for the memory feature */

/* Preset item layout improvements */
.preset-item {
    display: flex;
    flex-direction: column;
}

/* Buttons container for presets */
.preset-buttons {
    display: flex;
    gap: 10px;
    margin-top: 10px;
    margin-top: auto;
}

/* Continue button styling */
.preset-continue-btn {
    flex: 1;
    background-color: var(--success-color);
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: 5px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.preset-continue-btn:hover {
    background-color: var(--mastery-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.dark-mode .preset-continue-btn {
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.3);
}

.dark-mode .preset-continue-btn:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.4);
}

/* Select/Start New button styling */
.preset-select-btn {
    flex: 1;
    align-self: auto;
    padding: 10px 15px;
    font-size: 0.9rem;
}

/* Progress indicator badge for presets with saved progress */
.progress-badge {
    background-color: var(--success-color);
    color: white;
    font-size: 0.7rem;
    padding: 3px 8px;
    border-radius: 10px;
    position: absolute;
    top: 10px;
    right: 10px;
}

/* Progress bar in preset items */
.preset-progress-bar {
    height: 4px;
    background-color: #ecf0f1;
    border-radius: 2px;
    overflow: hidden;
    margin: 8px 0;
}

.dark-mode .preset-progress-bar {
    background-color: #455a64;
}

.preset-progress-fill {
    height: 100%;
    background-color: var(--success-color);
    transition: width 0.3s ease;
}

/* Responsive adjustments */
@media (max-width: 500px) {
    .preset-buttons {
        flex-direction: column;
    }
    
    .preset-continue-btn, .preset-select-btn {
        width: 100%;
    }
}

/* Replace or update the header styles in styles.css */
header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px 0;
    border-bottom: 2px solid var(--primary-color);
    cursor: pointer; /* Add cursor pointer to indicate it's clickable */
    transition: var(--transition);
}

header:hover {
    background-color: rgba(52, 152, 219, 0.05); /* Slight highlight on hover */
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
}

.dark-mode header:hover {
    background-color: rgba(52, 152, 219, 0.1);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

/* Add a small hint about clicking the header */
header::after {
    content: "Click to return home";
    display: block;
    font-size: 0.7rem;
    margin-top: 5px;
    color: #999;
    opacity: 0;
    transition: opacity 0.3s ease;
}

header:hover::after {
    opacity: 1;
}

.dark-mode header::after {
    color: #bbb;
}

/* Subject Categories Layout Styles */
.subject-categories-container {
    max-width: 900px;
    margin: 0 auto;
    animation: fadeIn 0.3s ease;
}

.subject-categories-header {
    text-align: center;
    margin-bottom: 30px;
}

.subject-categories-header h2 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.subject-categories-header p {
    color: #7f8c8d;
    font-size: 1.1rem;
}

.dark-mode .subject-categories-header p {
    color: #bdc3c7;
}

.subject-category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.subject-category-card {
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
    padding: 20px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
    display: flex;
    align-items: center;
    cursor: pointer;
    border: 2px solid transparent;
    height: 100%;
    min-height: 120px;
}

.dark-mode .subject-category-card {
    background-color: #3d4b5c;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.subject-category-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.1);
    border-color: var(--primary-color);
}

.dark-mode .subject-category-card:hover {
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.3);
}

.subject-category-icon {
    font-size: 2.5rem;
    margin-right: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 60px;
    height: 60px;
    background-color: rgba(52, 152, 219, 0.1);
    border-radius: 50%;
    padding: 10px;
}

.dark-mode .subject-category-icon {
    background-color: rgba(52, 152, 219, 0.2);
}

.subject-category-content {
    flex: 1;
}

.subject-category-content h3 {
    color: var(--primary-color);
    margin-bottom: 5px;
    font-size: 1.3rem;
}

.subject-category-content p {
    color: #7f8c8d;
    font-size: 0.9rem;
    margin-bottom: 8px;
    line-height: 1.4;
}

.dark-mode .subject-category-content p {
    color: #bdc3c7;
}

.preset-count {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    font-size: 0.8rem;
    padding: 3px 10px;
    border-radius: 12px;
}

.upload-own-container {
    background-color: rgba(52, 152, 219, 0.05);
    border-radius: var(--border-radius);
    padding: 20px;
    text-align: center;
    margin-top: 20px;
    border: 2px dashed #e0e0e0;
    transition: var(--transition);
}

.dark-mode .upload-own-container {
    background-color: rgba(52, 152, 219, 0.1);
    border-color: #546e7a;
}

.upload-own-container:hover {
    border-color: var(--primary-color);
}

.upload-own-container p {
    margin-bottom: 15px;
    color: #7f8c8d;
}

.dark-mode .upload-own-container p {
    color: #bdc3c7;
}

/* Empty categories message */
.no-categories-message {
    text-align: center;
    padding: 40px 20px;
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
    margin: 20px 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.dark-mode .no-categories-message {
    background-color: #3d4b5c;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.no-categories-message h3 {
    color: var(--primary-color);
    margin-bottom: 10px;
}

.no-categories-message p {
    color: #7f8c8d;
}

.dark-mode .no-categories-message p {
    color: #bdc3c7;
}

/* Subject Label in Presets Screen */
.subject-label {
    display: inline-block;
    background-color: rgba(52, 152, 219, 0.1);
    padding: 5px 10px;
    border-radius: 15px;
    color: var(--primary-color);
    font-size: 0.9rem;
    margin-bottom: 15px;
    border: 1px solid var(--primary-color);
}

.dark-mode .subject-label {
    background-color: rgba(52, 152, 219, 0.2);
}

/* Animation for categories */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.subject-category-card {
    animation: fadeInUp 0.3s ease;
    animation-fill-mode: both;
}

/* Staggered animations */
.subject-category-card:nth-child(1) { animation-delay: 0.05s; }
.subject-category-card:nth-child(2) { animation-delay: 0.1s; }
.subject-category-card:nth-child(3) { animation-delay: 0.15s; }
.subject-category-card:nth-child(4) { animation-delay: 0.2s; }
.subject-category-card:nth-child(5) { animation-delay: 0.25s; }

/* Responsive Adjustments */
@media (max-width: 768px) {
    .subject-category-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    }
    
    .subject-categories-header h2 {
        font-size: 1.8rem;
    }
    
    .subject-categories-header p {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .subject-category-grid {
        grid-template-columns: 1fr;
    }
    
    .subject-category-card {
        padding: 15px;
    }
    
    .subject-category-icon {
        font-size: 2rem;
        min-width: 50px;
        height: 50px;
    }
    
    .subject-categories-header h2 {
        font-size: 1.6rem;
    }
}