/* Scandinavian + Japanese + Drafting Board Aesthetic + Search Interface */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
    --paper-white: #fafafa;
    --ink-black: #1a1a1a;
    --graphite: #4a4a4a;
    --light-gray: #e5e5e5;
    --grid-gray: #d0d0d0;
    --accent-blue: #2563eb;
    --accent-red: #dc2626;
    --warm-beige: #f5f3f0;
    --shadow: rgba(0, 0, 0, 0.08);
    --border-radius: 2px;
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, sans-serif;
    font-weight: 400;
    line-height: 1.6;
    color: var(--ink-black);
    background: linear-gradient(135deg, var(--paper-white) 0%, var(--warm-beige) 100%);
    background-attachment: fixed;
    margin: 0;
    padding: 20px;
    min-height: 100vh;
    
    /* Drafting board grid pattern */
    background-image: 
        linear-gradient(var(--grid-gray) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid-gray) 1px, transparent 1px);
    background-size: 20px 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: var(--paper-white);
    border: 1px solid var(--light-gray);
    box-shadow: 
        0 1px 3px var(--shadow),
        0 10px 40px rgba(0, 0, 0, 0.03);
    position: relative;
    
    /* Drafting paper style */
    background-image: 
        linear-gradient(var(--grid-gray) 0.5px, transparent 0.5px),
        linear-gradient(90deg, var(--grid-gray) 0.5px, transparent 0.5px);
    background-size: 10px 10px;
}

.container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 40px;
    width: 2px;
    height: 100%;
    background: var(--accent-red);
    opacity: 0.3;
}

.header {
    padding: 40px 60px 30px;
    border-bottom: 2px solid var(--light-gray);
    background: var(--paper-white);
    position: relative;
}

.header::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 60px;
    right: 60px;
    height: 1px;
    background: var(--graphite);
}

h1 {
    font-size: 2.5rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    margin: 0 0 16px 0;
    color: var(--ink-black);
    position: relative;
}

.subtitle {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    color: var(--graphite);
    margin: 0;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.main-content {
    padding: 40px 60px;
}

.description {
    font-size: 1.1rem;
    color: var(--graphite);
    margin-bottom: 40px;
    line-height: 1.7;
}

.input-section {
    display: flex;
    justify-content: center;
    margin-bottom: 20px; /* Reduced margin for button below */
}

#arxivIdInput {
    flex-grow: 1;
    padding: 12px;
    border: 1px solid #c0c0c0; /* Lighter, more natural border */
    border-radius: 4px 0 0 4px;
    font-size: 16px;
    background-color: #fcfcfc; /* Off-white background */
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.05); /* Subtle inner shadow */
}

#generateExamBtn,
#downloadExamBtn {
    padding: 12px 25px;
    background-color: #3f51b5; /* A slightly muted blue, reminiscent of a blueprint */
    color: white;
    border: none;
    border-radius: 0 4px 4px 0;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    transition: background-color 0.2s ease, transform 0.1s ease;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1); /* Subtle outer shadow */
    -webkit-appearance: none; /* Reset default button styles */
    -moz-appearance: none;
    appearance: none;
}

#generateExamBtn:hover,
#downloadExamBtn:hover {
    background-color: #303f9f; /* Darker blue on hover */
    transform: translateY(-1px); /* Slight lift effect */
}

#generateExamBtn:active,
#downloadExamBtn:active {
    background-color: #263238; /* Even darker on active */
    transform: translateY(0); /* Press effect */
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.2); /* Inner shadow on click */
}

/* Separate style for download button specific positioning */
#downloadExamBtn {
    display: block; /* Override inline style */
    margin: 0 auto 30px auto; /* Center it and add space below */
    border-radius: 4px; /* Make it fully rounded */
    min-width: 200px; /* Ensure consistent width */
    background-color: #607d8b; /* A calm, grayish-blue */
    border: 1px solid #546e7a;
}

#downloadExamBtn:hover {
    background-color: #455a64; /* Darken on hover */
}

/* PDF Download Button Styles */
.download-pdf-btn, #downloadSinglePdfBtn {
    padding: 8px 16px;
    background-color: #28a745; /* Green for download action */
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background-color 0.2s ease, transform 0.1s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    margin-left: 8px;
    white-space: nowrap;
}

.download-pdf-btn:hover, #downloadSinglePdfBtn:hover {
    background-color: #218838;
    transform: translateY(-1px);
}

.download-pdf-btn:active, #downloadSinglePdfBtn:active {
    background-color: #1e7e34;
    transform: translateY(0);
    box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.2);
}

.download-pdf-btn:disabled, #downloadSinglePdfBtn:disabled {
    background-color: #6c757d;
    cursor: not-allowed;
    transform: none;
}

/* Result Actions Container */
.result-actions {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid var(--light-gray);
    display: flex;
    justify-content: flex-end;
}

/* Enhanced Stats Bar with Exam Name and Citation */
.exam-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--light-gray);
}

.exam-name .stat-value.exam-title {
    font-size: 1.1em;
    font-weight: 600;
    color: var(--accent-blue);
}

.paper-info {
    margin-top: 8px;
}

.citation {
    margin-top: 8px;
    padding: 8px 12px;
    background-color: var(--warm-beige);
    border-left: 3px solid var(--accent-blue);
    border-radius: 0 4px 4px 0;
}

.citation-text {
    font-style: italic;
    font-size: 0.95em;
    color: var(--graphite);
    line-height: 1.4;
    display: block;
    margin-top: 4px;
}

.loading {
    display: none;
    padding: 40px;
    color: var(--graphite);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
}

.progress-container {
    max-width: 600px;
    margin: 0 auto;
    padding: 32px;
    background: var(--paper-white);
    border: 2px solid var(--light-gray);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 12px var(--shadow);
}

.progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.progress-header h3 {
    font-size: 1.4rem;
    font-weight: 500;
    color: var(--ink-black);
    margin: 0;
    font-family: 'Inter', sans-serif;
}

.progress-percentage {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--accent-blue);
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--light-gray);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 32px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-blue), #1d4ed8);
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 4px;
}

.progress-steps {
    display: grid;
    gap: 16px;
}

.progress-step {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 12px 0;
    opacity: 0.4;
    transition: all 0.3s ease;
}

.progress-step.active {
    opacity: 1;
    color: var(--accent-blue);
}

.progress-step.completed {
    opacity: 0.7;
    color: #16a34a;
}

.step-icon {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--light-gray);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--graphite);
    transition: all 0.3s ease;
}

.progress-step.active .step-icon {
    background: var(--accent-blue);
    color: var(--paper-white);
    animation: pulse 2s infinite;
}

.progress-step.completed .step-icon {
    background: #16a34a;
    color: var(--paper-white);
}

.progress-step.completed .step-icon::before {
    content: '✓';
    font-size: 1rem;
}

.step-text {
    font-size: 1rem;
    font-weight: 400;
    flex: 1;
}

.progress-step.active .step-text {
    font-weight: 500;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        opacity: 1;
    }
    50% {
        transform: scale(1.05);
        opacity: 0.8;
    }
}

.exam-container {
    margin-top: 20px;
    border-top: 1px solid #e0e0e0; /* Lighter separator */
    padding-top: 20px;
}

.question {
    background-color: #fdfdfd; /* Very light background for questions */
    border: 1px solid #e0e0e0; /* Subtle border */
    border-radius: 6px;
    padding: 18px;
    margin-bottom: 18px;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.05); /* Soft shadow for depth */
}

.question::before {
    content: '';
    position: absolute;
    top: 0;
    left: 20px;
    width: 3px;
    height: 100%;
    background: var(--accent-blue);
    opacity: 0.4;
}

.question-number {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    color: var(--graphite);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.question-prompt {
    font-weight: 700; /* Bolder prompt */
    margin-bottom: 12px;
    color: #333333;
    line-height: 1.5; /* Improve readability */
}

.choices {
    display: grid;
    gap: 12px;
}

.choice-label {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 16px;
    border: 1px solid var(--light-gray);
    cursor: pointer;
    transition: all 0.2s ease;
    background: var(--paper-white);
}

.choice-label:hover {
    border-color: var(--accent-blue);
    background: rgba(37, 99, 235, 0.02);
}

.choice-label input[type="radio"] {
    margin: 4px 0 0 0;
    accent-color: var(--accent-blue);
}

.choice-text {
    flex: 1;
    line-height: 1.5;
}

.choice-letter {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 500;
    color: var(--graphite);
    min-width: 20px;
}

.error-container {
    color: #c0392b; /* A more subdued red for errors */
    text-align: center;
    margin-top: 25px;
    padding: 10px;
    background-color: #ffebeb; /* Light red background for error message */
    border: 1px solid #c0392b;
    border-radius: 5px;
}

.footer {
    margin-top: 50px;
    padding: 20px 0; /* Add padding to top/bottom, 0 for left/right */
    border-top: 1px solid #d0d0d0; /* A slightly softer border color */
    text-align: center;
    font-size: 0.9em;
    color: #616161;
    background-color: transparent; /* Make background transparent to blend with body */
    width: 100%;
    box-sizing: border-box;
}

.footer p {
    margin: 5px 0;
}

.footer a {
    color: #3f51b5;
    text-decoration: none;
    font-weight: 600;
}

.footer a:hover {
    text-decoration: underline;
}

.submit-section {
    margin: 40px 0;
    padding: 32px 0;
    border-top: 2px solid var(--light-gray);
    text-align: center;
}

.submit-btn {
    padding: 16px 48px;
    background: var(--accent-blue);
    color: var(--paper-white);
    border: 2px solid var(--accent-blue);
    font-family: 'Inter', sans-serif;
    font-weight: 600;
    font-size: 1rem;
    letter-spacing: 0.02em;
    cursor: pointer;
    transition: all 0.2s ease;
    text-transform: uppercase;
    border-radius: var(--border-radius);
}

.submit-btn:hover:not(:disabled) {
    background: var(--paper-white);
    color: var(--accent-blue);
}

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.results-container {
    margin-top: 40px;
    padding: 32px;
    background: var(--warm-beige);
    border: 2px solid var(--light-gray);
    border-radius: var(--border-radius);
}

.score-summary {
    text-align: center;
    margin-bottom: 32px;
    padding: 24px;
    background: var(--paper-white);
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
}

.score-display {
    font-size: 3rem;
    font-weight: 300;
    color: var(--ink-black);
    margin-bottom: 8px;
    font-family: 'JetBrains Mono', monospace;
}

.score-label {
    font-size: 1.1rem;
    color: var(--graphite);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.score-breakdown {
    display: flex;
    justify-content: center;
    gap: 32px;
    margin-top: 16px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
}

.score-item {
    text-align: center;
}

.score-value {
    display: block;
    font-size: 1.2rem;
    font-weight: 500;
    margin-bottom: 4px;
}

.correct { color: #16a34a; }
.incorrect { color: var(--accent-red); }
.unanswered { color: var(--graphite); }

/* Feedback states for questions */
.question.answered-correct {
    border-left: 4px solid #16a34a;
    background: rgba(22, 163, 74, 0.02);
}

.question.answered-incorrect {
    border-left: 4px solid var(--accent-red);
    background: rgba(220, 38, 38, 0.02);
}

.question.unanswered {
    border-left: 4px solid var(--graphite);
    background: rgba(74, 74, 74, 0.02);
}

.choice-label.correct-answer {
    border-color: #16a34a;
    background: rgba(22, 163, 74, 0.1);
}

.choice-label.user-answer.incorrect {
    border-color: var(--accent-red);
    background: rgba(220, 38, 38, 0.1);
}

.choice-label.correct-answer::after {
    content: '✓';
    color: #16a34a;
    font-weight: bold;
    margin-left: auto;
    font-size: 1.2rem;
}

.choice-label.user-answer.incorrect::after {
    content: '✗';
    color: var(--accent-red);
    font-weight: bold;
    margin-left: auto;
    font-size: 1.2rem;
}

/* Search Interface Styles */
.mode-toggle-section {
    margin-bottom: 2rem;
    text-align: center;
}

.mode-toggle {
    display: inline-flex;
    background: var(--light-gray);
    border-radius: var(--border-radius);
    padding: 4px;
    margin-bottom: 1rem;
}

.mode-btn {
    padding: 8px 16px;
    border: none;
    background: transparent;
    color: var(--graphite);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--border-radius);
    transition: all 0.2s;
}

.mode-btn.active {
    background: var(--paper-white);
    color: var(--ink-black);
    box-shadow: 0 1px 2px var(--shadow);
}

.mode-btn:hover:not(.active) {
    background: rgba(255, 255, 255, 0.5);
}

.mode-content {
    animation: fadeIn 0.3s ease;
}

.search-type-tabs {
    display: flex;
    background: var(--light-gray);
    border-radius: var(--border-radius);
    padding: 4px;
    margin-bottom: 1.5rem;
}

.search-tab {
    flex: 1;
    padding: 10px 16px;
    border: none;
    background: transparent;
    color: var(--graphite);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--border-radius);
    transition: all 0.2s;
}

.search-tab.active {
    background: var(--paper-white);
    color: var(--ink-black);
    box-shadow: 0 1px 2px var(--shadow);
}

.search-tab:hover:not(.active) {
    background: rgba(255, 255, 255, 0.5);
}

.search-panel {
    display: none;
    margin-bottom: 1.5rem;
}

.search-panel.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

.search-input-group {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.search-input {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
    font-size: 1rem;
    background: var(--paper-white);
    transition: border-color 0.2s;
}

.search-input:focus {
    outline: none;
    border-color: var(--accent-blue);
}

.search-select {
    padding: 12px 16px;
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
    background: var(--paper-white);
    font-size: 1rem;
    cursor: pointer;
}

.small-select {
    padding: 8px 12px;
    font-size: 0.9rem;
}

.search-help {
    font-size: 0.85rem;
    color: var(--graphite);
    padding: 0.5rem 0;
}

.search-help code {
    background: var(--light-gray);
    padding: 2px 6px;
    border-radius: 2px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
}

.date-filter {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0.5rem;
    font-size: 0.9rem;
}

.date-input {
    padding: 8px 12px;
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
    background: var(--paper-white);
    font-size: 0.9rem;
}

.search-btn, .search-exam-btn {
    background: var(--accent-blue);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    width: 100%;
}

.search-btn:hover, .search-exam-btn:hover {
    background: #1d4ed8;
    transform: translateY(-1px);
}

.search-results {
    margin-top: 2rem;
    border-top: 1px solid var(--light-gray);
    padding-top: 1.5rem;
}

.results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.results-header h3 {
    margin: 0;
    color: var(--ink-black);
}

.results-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-size: 0.9rem;
    flex-wrap: wrap;
}

.control-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.results-list {
    margin-bottom: 1.5rem;
}

.result-item {
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
    padding: 1rem;
    margin-bottom: 0.75rem;
    background: var(--paper-white);
    cursor: pointer;
    transition: all 0.2s;
}

.result-item:hover {
    border-color: var(--accent-blue);
    box-shadow: 0 2px 8px var(--shadow);
}

.result-item.selected {
    border-color: var(--accent-blue);
    background: rgba(37, 99, 235, 0.02);
}

.result-title {
    font-weight: 600;
    color: var(--ink-black);
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.result-authors {
    color: var(--graphite);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.result-abstract {
    color: var(--graphite);
    font-size: 0.85rem;
    line-height: 1.4;
    margin-bottom: 0.5rem;
}

.result-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: var(--graphite);
}

.result-categories {
    display: flex;
    gap: 0.25rem;
}

.category-tag {
    background: var(--light-gray);
    padding: 2px 6px;
    border-radius: 2px;
    font-size: 0.75rem;
}

.pagination {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
}

.page-btn {
    padding: 8px 12px;
    border: 1px solid var(--light-gray);
    background: var(--paper-white);
    color: var(--graphite);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
}

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

.page-btn.active {
    background: var(--accent-blue);
    color: white;
    border-color: var(--accent-blue);
}

.page-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.feedback-explanation {
    margin-top: 16px;
    padding: 16px;
    background: var(--warm-beige);
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
    font-size: 0.95rem;
    line-height: 1.6;
}

.feedback-explanation strong {
    color: var(--ink-black);
}

.restart-btn {
    padding: 12px 24px;
    background: var(--paper-white);
    color: var(--ink-black);
    border: 2px solid var(--light-gray);
    font-family: 'Inter', sans-serif;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-top: 24px;
    border-radius: var(--border-radius);
}

.restart-btn:hover {
    border-color: var(--ink-black);
}

/* Open-ended question styles */
.open-ended-answer {
    width: 100%;
    min-height: 120px;
    padding: 16px;
    border: 2px solid var(--light-gray);
    border-radius: var(--border-radius);
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    line-height: 1.6;
    background: var(--paper-white);
    color: var(--ink-black);
    resize: vertical;
    transition: border-color 0.2s ease;
}

.open-ended-answer:focus {
    outline: none;
    border-color: var(--accent-blue);
}

.open-ended-answer::placeholder {
    color: var(--graphite);
    opacity: 0.7;
}

.open-ended-answer:disabled {
    background: var(--warm-beige);
    opacity: 0.8;
    cursor: not-allowed;
}

.question-type-badge {
    display: inline-block;
    padding: 4px 12px;
    background: var(--accent-blue);
    color: var(--paper-white);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-radius: 12px;
    margin-bottom: 16px;
}

.question-type-badge.open-ended {
    background: var(--graphite);
}

.sample-answer {
    margin-top: 16px;
    padding: 16px;
    background: rgba(37, 99, 235, 0.05);
    border: 1px solid rgba(37, 99, 235, 0.2);
    border-radius: var(--border-radius);
}

.sample-answer-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--accent-blue);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.key-points {
    margin-top: 12px;
}

.key-points-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--graphite);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.key-points-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.key-points-list li {
    padding: 4px 0;
    padding-left: 16px;
    position: relative;
}

.key-points-list li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--accent-blue);
    font-weight: bold;
}

.char-count {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--graphite);
    text-align: right;
    margin-top: 8px;
}

.char-count.warning {
    color: var(--accent-red);
}

/* Teacher Mode Styles */
.teacher-mode-toggle {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 24px;
    padding: 16px;
    background: rgba(37, 99, 235, 0.05);
    border: 1px solid rgba(37, 99, 235, 0.2);
    border-radius: var(--border-radius);
}

.teacher-mode-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--accent-blue);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.toggle-switch {
    position: relative;
    width: 50px;
    height: 24px;
    background: var(--light-gray);
    border-radius: 12px;
    cursor: pointer;
    transition: background 0.2s ease;
}

.toggle-switch.active {
    background: var(--accent-blue);
}

.toggle-slider {
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background: var(--paper-white);
    border-radius: 50%;
    transition: transform 0.2s ease;
}

.toggle-switch.active .toggle-slider {
    transform: translateX(26px);
}

.teacher-mode-description {
    font-size: 0.85rem;
    color: var(--graphite);
    margin-left: auto;
    max-width: 300px;
}

/* LLM Configuration Styles */
.llm-config-section {
    margin-bottom: 32px;
    padding: 20px;
    background: rgba(220, 38, 38, 0.02);
    border: 1px solid rgba(220, 38, 38, 0.1);
    border-radius: var(--border-radius);
}

.llm-config-section h3 {
    margin: 0 0 16px 0;
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--ink-black);
    font-family: 'Inter', sans-serif;
}

.config-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 12px;
}

.config-item {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.config-item.full-width {
    grid-column: 1 / -1;
    flex-direction: row;
    align-items: center;
    gap: 12px;
}

.config-item label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--graphite);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.config-select, .config-input {
    padding: 8px 12px;
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    background: var(--paper-white);
    color: var(--ink-black);
    transition: border-color 0.2s ease;
}

.config-select:focus, .config-input:focus {
    outline: none;
    border-color: var(--accent-blue);
}

.config-input {
    flex: 1;
    min-width: 300px;
}

.save-btn {
    padding: 8px 16px;
    background: var(--accent-red);
    color: var(--paper-white);
    border: 1px solid var(--accent-red);
    border-radius: var(--border-radius);
    font-family: 'Inter', sans-serif;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.save-btn:hover {
    background: var(--paper-white);
    color: var(--accent-red);
}

.config-status {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    padding: 8px 0;
    color: var(--graphite);
}

.config-status.success {
    color: #16a34a;
}

.config-status.error {
    color: var(--accent-red);
}

/* Exam Generation Controls */
.exam-generation-controls {
    margin-top: 20px;
    padding: 16px;
    background: rgba(37, 99, 235, 0.03);
    border: 1px solid rgba(37, 99, 235, 0.1);
    border-radius: var(--border-radius);
}

.exam-input-group {
    display: flex;
    gap: 8px;
    align-items: center;
    flex-wrap: wrap;
}

.arxiv-input {
    flex: 1;
    min-width: 200px;
    padding: 10px 12px;
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    background: var(--paper-white);
    color: var(--ink-black);
    transition: border-color 0.2s ease;
}

.arxiv-input:focus {
    outline: none;
    border-color: var(--accent-blue);
}

.arxiv-input::placeholder {
    color: var(--graphite);
    opacity: 0.7;
}

.generate-btn {
    padding: 10px 20px;
    background: var(--accent-blue);
    color: var(--paper-white);
    border: 1px solid var(--accent-blue);
    border-radius: var(--border-radius);
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.generate-btn:hover {
    background: var(--paper-white);
    color: var(--accent-blue);
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(37, 99, 235, 0.2);
}

.generate-btn:active {
    transform: translateY(0);
}

.generate-btn:disabled {
    background: var(--graphite);
    border-color: var(--graphite);
    color: var(--paper-white);
    cursor: not-allowed;
    transform: none;
}

@media (max-width: 768px) {
    .exam-input-group {
        flex-direction: column;
        align-items: stretch;
    }
    
    .arxiv-input {
        min-width: auto;
    }
}

/* Teacher Mode Answer Display */
.teacher-answers {
    margin-top: 24px;
    padding: 20px;
    background: rgba(220, 38, 38, 0.02);
    border: 2px solid rgba(220, 38, 38, 0.1);
    border-radius: var(--border-radius);
}

.teacher-answers-header {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--accent-red);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.teacher-answers-header::before {
    content: '👨‍🏫';
    font-size: 1.2rem;
}

.mc-correct-answer {
    background: rgba(22, 163, 74, 0.1);
    border: 1px solid rgba(22, 163, 74, 0.3);
    padding: 12px;
    border-radius: var(--border-radius);
    margin-bottom: 16px;
}

.mc-correct-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    font-weight: 500;
    color: #16a34a;
    margin-bottom: 8px;
}

.graded-examples {
    display: grid;
    gap: 16px;
}

.graded-example {
    border: 1px solid var(--light-gray);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.example-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    background: var(--warm-beige);
    border-bottom: 1px solid var(--light-gray);
}

.example-score {
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--ink-black);
}

.score-1 { color: #dc2626; }
.score-2 { color: #ea580c; }
.score-3 { color: #d97706; }
.score-4 { color: #16a34a; }
.score-5 { color: #0d9488; }

.example-content {
    padding: 16px;
}

.example-answer {
    margin-bottom: 12px;
    line-height: 1.6;
}

.example-feedback {
    font-size: 0.9rem;
    color: var(--graphite);
    padding: 12px;
    background: var(--warm-beige);
    border-radius: var(--border-radius);
    border-left: 3px solid var(--accent-blue);
}

.example-feedback strong {
    color: var(--ink-black);
}

.teacher-mode-active .question {
    border-left: 4px solid var(--accent-red) !important;
}

.teacher-mode-active .submit-section {
    display: none;
}

.stats-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
    margin-bottom: 32px;
    border-bottom: 1px solid var(--light-gray);
}

.stat {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    color: var(--graphite);
}

.stat-value {
    font-weight: 500;
    color: var(--ink-black);
}

@media (max-width: 768px) {
    body {
        padding: 8px;
        background-size: 15px 15px;
        min-height: 100vh;
    }
    
    .container {
        background-size: 8px 8px;
        margin: 0;
        border-radius: 8px;
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    }
    
    .container::before {
        left: 15px;
    }
    
    .header {
        padding: 20px 20px 16px 20px;
        text-align: center;
    }
    
    .main-content {
        padding: 0 20px 20px 20px;
    }
    
    h1 {
        font-size: 1.8rem;
        margin-bottom: 4px;
    }
    
    .subtitle {
        font-size: 0.9rem;
        margin-bottom: 16px;
    }
    
    /* Mode Toggle Mobile */
    .mode-toggle-section {
        margin-bottom: 20px;
    }
    
    .mode-toggle {
        padding: 3px;
        border-radius: 8px;
        margin: 0 auto;
        max-width: 280px;
    }
    
    .mode-btn {
        padding: 12px 16px;
        font-size: 0.9rem;
        border-radius: 6px;
    }
    
    /* Description text mobile */
    .description {
        font-size: 0.9rem;
        line-height: 1.5;
        margin-bottom: 16px;
        text-align: center;
    }
    
    /* Teacher Mode Mobile */
    .teacher-mode-toggle {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 12px;
        margin-bottom: 24px;
        padding: 16px;
        background: rgba(26, 26, 26, 0.02);
        border-radius: 8px;
    }
    
    .teacher-mode-description {
        margin-left: 0;
        margin-top: 0;
        max-width: none;
        font-size: 0.85rem;
    }
    
    /* LLM Config Mobile */
    .llm-config-section {
        margin-bottom: 24px;
        padding: 16px;
        border-radius: 8px;
    }
    
    .llm-config-section h3 {
        font-size: 1rem;
        margin-bottom: 16px;
        text-align: center;
    }
    
    .config-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    
    .config-item.full-width {
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
    }
    
    .config-input {
        min-width: unset;
        padding: 12px;
        font-size: 0.9rem;
    }
    
    .save-btn {
        padding: 12px 20px;
        font-size: 0.85rem;
        align-self: flex-end;
        max-width: 120px;
    }
    
    /* Exam Generation Controls Mobile */
    .exam-generation-controls {
        padding: 16px;
        margin-top: 16px;
        border-radius: 8px;
    }
    
    .exam-input-group {
        flex-direction: column;
        align-items: stretch;
        gap: 12px;
    }
    
    .arxiv-input {
        min-width: auto;
        padding: 12px;
        font-size: 0.9rem;
        text-align: center;
    }
    
    .generate-btn {
        padding: 14px 20px;
        font-size: 0.95rem;
        font-weight: 600;
    }
    
    .download-pdf-btn {
        padding: 12px 16px;
        font-size: 0.85rem;
    }
    
    /* Search Interface Mobile */
    .search-options {
        margin-top: 16px;
    }
    
    .search-type-tabs {
        margin-bottom: 16px;
        padding: 3px;
    }
    
    .search-tab {
        padding: 10px 12px;
        font-size: 0.85rem;
    }
    
    .search-input-group {
        flex-direction: column;
        gap: 12px;
    }
    
    .search-input, .search-select {
        padding: 12px;
        font-size: 0.9rem;
    }
    
    .search-btn, .search-exam-btn {
        padding: 14px 20px;
        font-size: 0.95rem;
        width: 100%;
    }
    
    /* Search Results Mobile */
    .results-header {
        flex-direction: column;
        align-items: stretch;
        gap: 16px;
    }
    
    .results-controls {
        flex-direction: column;
        gap: 12px;
    }
    
    .control-group {
        justify-content: space-between;
        flex-wrap: wrap;
        gap: 8px;
    }
    
    .result-item {
        padding: 16px;
        margin-bottom: 12px;
        border-radius: 8px;
    }
    
    .result-title {
        font-size: 1rem;
        line-height: 1.3;
        margin-bottom: 8px;
    }
    
    .result-authors {
        font-size: 0.85rem;
        margin-bottom: 8px;
    }
    
    .result-abstract {
        font-size: 0.85rem;
        line-height: 1.4;
    }
    
    .result-meta {
        margin-top: 12px;
        flex-direction: column;
        gap: 8px;
    }
    
    .category-tag {
        font-size: 0.75rem;
        padding: 3px 6px;
    }
    
    /* Progress Indicator Mobile */
    .loading {
        padding: 20px;
    }
    
    .progress-container {
        max-width: none;
    }
    
    .progress-header h3 {
        font-size: 1.1rem;
    }
    
    .progress-steps {
        gap: 8px;
        padding: 0;
    }
    
    .progress-step {
        padding: 8px 12px;
        border-radius: 6px;
    }
    
    .step-icon {
        width: 24px;
        height: 24px;
        font-size: 0.8rem;
        line-height: 24px;
    }
    
    .step-text {
        font-size: 0.8rem;
        margin-left: 8px;
    }
    
    /* Stats Bar Mobile */
    .stats-bar {
        padding: 12px;
        border-radius: 6px;
        margin-bottom: 16px;
    }
    
    .exam-header {
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
        margin-bottom: 12px;
        padding-bottom: 12px;
    }
    
    .exam-name .stat-value.exam-title {
        font-size: 1rem;
        text-align: center;
    }
    
    .stat-label {
        font-size: 0.8rem;
    }
    
    .stat-value {
        font-size: 0.9rem;
    }
    
    .citation {
        margin-top: 12px;
        padding: 12px;
        border-radius: 6px;
    }
    
    .citation-text {
        font-size: 0.85rem;
        line-height: 1.5;
    }
    
    /* Questions Mobile */
    .question {
        margin-bottom: 20px;
        padding: 16px;
        border-radius: 8px;
    }
    
    .question-number {
        font-size: 0.8rem;
        margin-bottom: 8px;
    }
    
    .question-prompt {
        font-size: 0.95rem;
        line-height: 1.4;
        margin-bottom: 16px;
    }
    
    .choices {
        gap: 8px;
    }
    
    .choice {
        padding: 12px;
        border-radius: 6px;
    }
    
    .choice-letter {
        font-size: 0.9rem;
        min-width: 24px;
    }
    
    .choice-text {
        font-size: 0.9rem;
        line-height: 1.3;
    }
    
    .open-ended-input textarea {
        min-height: 120px;
        padding: 12px;
        font-size: 0.9rem;
        border-radius: 6px;
    }
    
    .char-count {
        font-size: 0.75rem;
        margin-top: 6px;
    }
    
    /* Submit Section Mobile */
    .submit-section {
        padding: 20px 0;
        text-align: center;
    }
    
    .submit-btn {
        width: 100%;
        max-width: 280px;
        padding: 16px 24px;
        font-size: 1rem;
        border-radius: 8px;
    }
    
    /* Footer Mobile */
    .footer {
        padding: 16px 20px;
        text-align: center;
    }
    
    .footer p {
        font-size: 0.8rem;
        margin-bottom: 4px;
    }
    
    /* Download Button Mobile */
    #downloadExamBtn {
        width: 100%;
        max-width: 280px;
        margin: 16px auto;
        padding: 12px 20px;
        font-size: 0.9rem;
        border-radius: 8px;
    }
}