/* Create Set - Styles for creating new study sets */
.create-set-wrapper {
    display: flex;
    animation: fadeIn var(--transition-speed);
    min-height: calc(100vh - var(--navbar-height));
    /* centre column gets all remaining space between the two fixed sidebars */
    margin-left: 200px;  /* width of Quick Jump sidebar */
    margin-right: 260px; /* width of Distribution sidebar */
}

.sidebar-container {
    display: flex;
    flex-direction: column;
    padding-right: var(--spacing-lg);
    border-right: 1px solid var(--color-secondary);
    height: calc(100vh - var(--navbar-height));
    width: 180px;
    position: fixed;
    top: var(--navbar-height);
    left: 0;
    z-index: 5;
}

.sidebar-header {
    position: sticky;
    top: 0;
    background: var(--color-primary);
    z-index: 10;
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--color-border);
}

.sidebar-title {
    font-size: var(--font-size-md);
    font-weight: 600;
    color: var(--color-secondary);
    text-align: center;
    margin: 0;
}

.sidebar-content {
    flex: 1;
    overflow-y: auto;
    padding-top: var(--spacing-md);
    scrollbar-width: thin;
    scrollbar-color: var(--color-border) transparent;
}

.sidebar-content::-webkit-scrollbar {
    width: 6px;
}

.sidebar-content::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar-content::-webkit-scrollbar-thumb {
    background-color: var(--color-border);
    border-radius: 3px;
}

.sidebar-content::-webkit-scrollbar-thumb:hover {
    background-color: var(--color-secondary);
}

/* Up / Down navigation buttons in Quick Jump */
.sidebar-nav-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) 0 var(--spacing-sm);
}

.btn-sidebar-nav {
    flex: 1;
    background: rgba(255,255,255,0.06);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-secondary);
    font-size: var(--font-size-md);
    padding: 6px var(--spacing-xs);
    cursor: pointer;
    transition: background var(--transition-speed);
    text-align: center;
    line-height: 1;
}

.btn-sidebar-nav:hover {
    background: rgba(255,255,255,0.12);
}

/* ── Right Distribution Sidebar ─────────────────────────────────────────── */
.dist-sidebar-container {
    display: flex;
    flex-direction: column;
    width: 240px;
    height: calc(100vh - var(--navbar-height));
    position: fixed;
    top: var(--navbar-height);
    right: 0;
    border-left: 1px solid var(--color-secondary);
    z-index: 5;
    background: var(--color-primary);
}

.dist-sidebar-header {
    background: var(--color-primary);
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
    text-align: center;
}

.dist-sidebar-content {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-md);
    scrollbar-width: thin;
    scrollbar-color: var(--color-border) transparent;
}

.dist-sidebar-content::-webkit-scrollbar { width: 6px; }
.dist-sidebar-content::-webkit-scrollbar-track { background: transparent; }
.dist-sidebar-content::-webkit-scrollbar-thumb {
    background-color: var(--color-border);
    border-radius: 3px;
}
.dist-sidebar-content::-webkit-scrollbar-thumb:hover {
    background-color: var(--color-secondary);
}

.dist-section-title {
    padding-bottom: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
}


.questions-sidebar {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xs);
    padding: 0 var(--spacing-xs);
}

.sidebar-number-box {
    width: 100%;
    min-height: 36px;
    background-color: var(--color-active);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: flex-start;
    padding: 3px 6px;
    font-weight: 600;
    color: var(--color-secondary);
    cursor: pointer;
    transition: all var(--transition-speed);
    gap: 4px;
}

.sidebar-num-label {
    flex: 1;
    min-width: 0;
    text-align: left;
    font-size: inherit;
    font-weight: 600;
    line-height: 1;
}

.sidebar-hji {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1px;
    flex-shrink: 0;
}

.sidebar-hji-letter {
    font-size: 7px;
    font-weight: 700;
    line-height: 1;
    letter-spacing: 0;
}

.sidebar-hji-letter.has-it {
    color: #4ade80;
}

.sidebar-hji-letter.missing {
    color: #f87171;
}

.sidebar-number-box:hover {
    border-color: var(--color-secondary);
    background-color: var(--color-hover);
}

.sidebar-number-box.unfinished {
    border: 2px solid #FFD700;
    box-shadow: 0 0 8px rgba(255, 215, 0, 0.3);
}

.sidebar-number-box.duplicate {
    border: 2px solid #ff4444;
    box-shadow: 0 0 8px rgba(255, 68, 68, 0.4);
    background-color: rgba(255, 68, 68, 0.1);
    color: #ff4444;
}

.sidebar-number-box.invalid {
    border: 2px solid #ff4444;
    box-shadow: 0 0 8px rgba(255, 68, 68, 0.4);
    background-color: rgba(255, 68, 68, 0.1);
    color: #ff4444;
}

.create-set-container {
    flex: 1;
    min-width: 0;
    padding: var(--spacing-lg) var(--spacing-xl);
}

.btn-back {
    background: none;
    border: none;
    color: var(--color-secondary);
    font-size: var(--font-size-md);
    cursor: pointer;
    padding: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    transition: opacity var(--transition-speed);
}

.btn-back:hover {
    opacity: 0.7;
}

.create-set-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    font-size: var(--font-size-sm);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    margin-top: var(--spacing-md);
    color: #999999;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-input {
    width: 100%;
    padding: var(--spacing-md);
    background-color: var(--color-primary);
    border: none;
    border-bottom: 2px solid var(--color-border);
    border-radius: 0;
    color: var(--color-secondary);
    font-size: var(--font-size-md);
    transition: border-color var(--transition-speed);
    margin-bottom: var(--spacing-md);
}

.form-input:focus {
    outline: none;
    border-bottom-color: var(--color-secondary);
}

.form-textarea {
    width: 100%;
    min-height: 100px;
    padding: var(--spacing-md);
    background-color: var(--color-primary);
    border: none;
    border-bottom: 2px solid var(--color-border);
    border-radius: 0;
    color: var(--color-secondary);
    font-size: var(--font-size-md);
    transition: border-color var(--transition-speed);
    margin-bottom: var(--spacing-md);
    resize: vertical;
    font-family: inherit;
}

.form-textarea:focus {
    outline: none;
    border-bottom-color: var(--color-secondary);
}

/* ── Set / Lesson permanent UID row ─────────────────────────────────────── */
.set-uid-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--color-primary);
    border: 1px solid var(--color-border);
    border-radius: 6px;
}

.set-uid-value {
    flex: 1;
    font-family: 'Courier New', Courier, monospace;
    font-size: var(--font-size-md);
    font-weight: 700;
    letter-spacing: 2px;
    color: var(--color-secondary);
    user-select: all;
}

.btn-copy-uid {
    padding: 4px 10px;
    font-size: var(--font-size-xs, 11px);
    font-weight: 600;
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    color: #999;
    cursor: pointer;
    transition: background var(--transition-speed), color var(--transition-speed);
    white-space: nowrap;
}

.btn-copy-uid:hover {
    background: var(--color-border);
    color: var(--color-secondary);
}

.visibility-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin: var(--spacing-lg) 0;
}

.visibility-checkbox {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--color-secondary);
}

.visibility-label {
    color: var(--color-secondary);
    font-size: var(--font-size-md);
    cursor: pointer;
}

/* ── Set Publicity section ──────────────────────────────────────────────── */
.set-publicity-section {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-md) var(--spacing-lg);
    background: rgba(0, 0, 0, 0.18);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
}

.form-section-heading {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: #999999;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin: 0 0 var(--spacing-sm) 0;
}

.set-publicity-section .visibility-container {
    margin: var(--spacing-sm) 0 0 0;
}

.edit-password-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-xs);
    padding-left: 28px;
}

.edit-password-input {
    flex: 1;
    margin-bottom: 0;
}

.btn-set-password {
    flex-shrink: 0;
    padding: 6px 14px;
    font-size: var(--font-size-sm);
    font-weight: 600;
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-secondary);
    cursor: pointer;
    white-space: nowrap;
    transition: background var(--transition-speed), border-color var(--transition-speed), color var(--transition-speed);
}

.btn-set-password:hover {
    background: rgba(255, 255, 255, 0.07);
    border-color: var(--color-secondary);
}

.btn-set-password--confirmed {
    border-color: #4ade80;
    color: #4ade80;
}

.btn-set-password--confirmed:hover {
    background: rgba(74, 222, 128, 0.08);
}

.separator {
    width: 100%;
    height: 1px;
    background-color: var(--color-secondary);
    margin: var(--spacing-xl) 0;
}

.questions-container {
    margin-bottom: var(--spacing-lg);
}

.create-set-button-container {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.add-question-wrapper {
    position: relative;
    display: inline-block;
}

.add-question-btn {
    min-width: 160px;
}

.btn-finalize {
    padding: var(--spacing-md) var(--spacing-xl);
    background-color: var(--color-secondary);
    color: var(--color-primary);
    border-radius: var(--border-radius);
    font-weight: 600;
    font-size: var(--font-size-md);
    transition: opacity var(--transition-speed);
    cursor: pointer;
    border: 2px solid var(--color-secondary);
}

.btn-finalize:hover {
    opacity: 0.9;
}

.question-type-dropdown {
    position: absolute;
    bottom: calc(100% + var(--spacing-xs));
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--color-active);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    min-width: 300px;
    z-index: 10;
    box-shadow: 0 -4px 12px rgba(0,0,0,0.4);
    overflow: hidden;
}

/* Bulk-add quantity row inside the dropdown */
.bulk-quantity-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
}

.bulk-quantity-label {
    font-size: var(--font-size-xs);
    color: #999;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-right: 2px;
    flex-shrink: 0;
}

.bulk-qty-btn {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-secondary);
    cursor: pointer;
    font-size: var(--font-size-sm);
    font-weight: 600;
    padding: 3px 10px;
    transition: background var(--transition-speed), border-color var(--transition-speed);
    flex: 1;
}

.bulk-qty-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: var(--color-secondary);
}

.bulk-qty-btn.bulk-qty-selected {
    background: var(--color-secondary);
    border-color: var(--color-secondary);
    color: var(--color-primary);
}

.bulk-divider {
    height: 1px;
    background: var(--color-border);
    margin: 0 var(--spacing-sm);
}

/* Finalize/Update Set button sitting inside the right sidebar */
.sidebar-finalize-btn {
    width: 100%;
    margin-top: 0;
}

/* Divider below the finalize button, above Answer Distribution */
.sidebar-divider {
    border: none;
    border-top: 1px solid var(--color-border);
    margin: var(--spacing-md) 0;
}

/* Delete Set button inside the right sidebar */
.sidebar-delete-btn {
    width: 100%;
    margin-top: var(--spacing-sm);
    background: transparent;
    border: 1px solid #f44336;
    color: #f44336;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-sm);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background var(--transition-speed), color var(--transition-speed);
}

.sidebar-delete-btn:hover {
    background: rgba(244, 67, 54, 0.12);
}

/* T/F locked answer inputs */
.tf-locked {
    background: rgba(255, 255, 255, 0.04);
    color: rgba(255, 255, 255, 0.5);
    cursor: default;
    pointer-events: none;
}

/* Badge shown on the card number for question type */
.question-type-badge {
    display: inline-block;
    margin-left: var(--spacing-sm);
    padding: 1px 6px;
    border-radius: 4px;
    border: 1px solid transparent;
    font-size: var(--font-size-xs);
    font-weight: 700;
    background: rgba(255, 255, 255, 0.12);
    color: rgba(255, 255, 255, 0.6);
    vertical-align: middle;
    letter-spacing: 0.05em;
}

.dropdown-options-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
}

.dropdown-option {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-xs);
    background: none;
    border: none;
    border-right: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
    color: var(--color-secondary);
    text-align: center;
    cursor: pointer;
    font-size: var(--font-size-sm);
    transition: background-color var(--transition-speed);
    line-height: 1.3;
}

.dropdown-option:hover {
    background-color: var(--color-hover);
}

/* Remove right border on every 3rd cell (last column) */
.dropdown-option:nth-child(3n) {
    border-right: none;
}

/* Remove bottom border on last row (items 7, 8, 9) */
.dropdown-option:nth-child(n+7) {
    border-bottom: none;
}

.question-card {
    background-color: var(--color-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: 0;
    margin-bottom: var(--spacing-lg);
    overflow: hidden;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
    background-color: var(--color-active);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.btn-unfinished {
    background: none;
    border: 1px solid var(--color-border);
    color: #FFD700;
    font-size: 20px;
    cursor: pointer;
    padding: var(--spacing-xs);
    line-height: 1;
    transition: all var(--transition-speed);
    border-radius: var(--border-radius);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-unfinished:hover {
    border-color: #FFD700;
    background-color: rgba(255, 215, 0, 0.1);
}

.btn-unfinished.active {
    background-color: rgba(255, 215, 0, 0.2);
    border-color: #FFD700;
}

.btn-duplicate-question {
    background: none;
    border: 1px solid var(--color-border);
    color: #87CEEB;
    font-size: 16px;
    cursor: pointer;
    padding: var(--spacing-xs);
    line-height: 1;
    transition: all var(--transition-speed);
    border-radius: var(--border-radius);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-duplicate-question:hover {
    border-color: #87CEEB;
    background-color: rgba(135, 206, 235, 0.1);
}


.duplicate-question {
    border: 2px solid #ff4444 !important;
    box-shadow: 0 0 8px rgba(255, 68, 68, 0.3);
}

.duplicate-alert {
    background-color: rgba(255, 68, 68, 0.1);
    border: 1px solid #ff4444;
    border-radius: var(--border-radius);
    color: #ff4444;
    padding: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    font-size: var(--font-size-sm);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.invalid-question {
    border: 2px solid #ff4444 !important;
    box-shadow: 0 0 8px rgba(255, 68, 68, 0.3);
}

.validation-alert {
    background-color: rgba(255, 68, 68, 0.1);
    border: 1px solid #ff4444;
    border-radius: var(--border-radius);
    color: #ff4444;
    padding: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    font-size: var(--font-size-sm);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.card-number {
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: var(--color-secondary);
}

.btn-delete-question {
    background: none;
    border: none;
    color: #ff4444;
    font-size: 24px;
    cursor: pointer;
    padding: 0;
    line-height: 1;
    transition: opacity var(--transition-speed);
    font-weight: bold;
}

.btn-delete-question:hover {
    opacity: 0.7;
}

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

.question-textarea {
    min-height: 76px;
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-xl);
}

.answers-section {
    margin-top: var(--spacing-xl);
}

.answers-label {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: #999999;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--spacing-sm);
}

/* Manual distractor lock */
.manual-lock-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
    padding: 5px var(--spacing-sm);
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    width: fit-content;
}

.manual-lock-checkbox {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
    cursor: pointer;
    accent-color: var(--color-secondary);
    margin: 0;
}

.manual-lock-label {
    font-size: var(--font-size-xs);
    color: #999;
    cursor: pointer;
    user-select: none;
    white-space: nowrap;
}

.manual-lock-row:has(.manual-lock-checkbox:checked) {
    border-color: var(--color-secondary);
    background: rgba(255, 255, 255, 0.08);
}

.manual-lock-row:has(.manual-lock-checkbox:checked) .manual-lock-label {
    color: var(--color-secondary);
}

.answer-row-wrapper {
    margin-bottom: var(--spacing-md);
}

.answer-row {
    display: grid;
    grid-template-columns: auto 1fr auto;
    gap: var(--spacing-sm);
    align-items: center;
}

.btn-justification {
    background: none;
    border: 1px solid var(--color-border);
    color: var(--color-secondary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius);
    font-size: var(--font-size-sm);
    cursor: pointer;
    transition: border-color var(--transition-speed);
    white-space: nowrap;
}

.btn-justification:hover {
    border-color: var(--color-secondary);
}

.justification-textarea {
    margin-top: var(--spacing-sm);
    min-height: 60px;
}

.checkbox-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.answer-checkbox {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--color-secondary);
}

.checkbox-label {
    font-size: 11px;
    font-weight: 600;
    color: #666666;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    cursor: pointer;
    min-height: 18px; /* Maintain layout even when empty */
}

.answer-input {
    margin-bottom: 0;
    background-color: var(--color-active);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-sm) var(--spacing-md);
}

.answer-input:focus {
    border-color: var(--color-secondary);
}

.btn-primary {
    padding: var(--spacing-md) var(--spacing-xl);
    background-color: var(--color-secondary);
    color: var(--color-primary);
    border-radius: var(--border-radius);
    font-weight: 600;
    font-size: var(--font-size-md);
    transition: opacity var(--transition-speed);
    cursor: pointer;
}

.btn-primary:hover {
    opacity: 0.9;
}

/* Hint Field Styles */
.hint-label {
    display: block;
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    font-weight: 500;
    margin: var(--spacing-md) 0 var(--spacing-xs) 0;
}

.hint-textarea {
    min-height: 72px;
    margin-bottom: var(--spacing-md);
    opacity: 0.8;
    font-style: italic;
}

.hint-textarea:focus {
    opacity: 1;
}

/* ── Question image upload ───────────────────────────────────────────────── */
.question-image-section {
    margin-top: var(--spacing-md);
}

/* Toggle "See Image / Hide Image" button */
.btn-image-toggle {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px var(--spacing-sm);
    background: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    cursor: pointer;
    margin-bottom: var(--spacing-sm);
    transition: border-color var(--transition-speed), background var(--transition-speed);
}

.btn-image-toggle:hover {
    border-color: var(--color-secondary);
    background: rgba(255, 255, 255, 0.06);
}

/* Preview image */
.image-preview-wrap {
    position: relative;
    display: inline-block;
    margin-bottom: var(--spacing-sm);
}

.question-preview-img {
    max-width: 100%;
    max-height: 280px;
    border-radius: var(--border-radius);
    border: 1px solid var(--color-border);
    display: block;
}

.btn-remove-image {
    position: absolute;
    top: 6px;
    right: 6px;
    padding: 3px 8px;
    background: rgba(0, 0, 0, 0.65);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--border-radius);
    color: #ff6b6b;
    font-size: var(--font-size-sm);
    cursor: pointer;
    transition: background var(--transition-speed);
}

.btn-remove-image:hover {
    background: rgba(220, 53, 69, 0.5);
}

/* Drag & drop zone */
.image-drop-zone {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-md) var(--spacing-lg);
    border: 2px dashed var(--color-border);
    border-radius: var(--border-radius);
    text-align: center;
    cursor: pointer;
    transition: border-color var(--transition-speed), background var(--transition-speed);
    background: rgba(255, 255, 255, 0.02);
    user-select: none;
}

.image-drop-zone:hover,
.image-drop-zone.drag-over {
    border-color: var(--color-secondary);
    background: rgba(255, 255, 255, 0.05);
}

.image-drop-zone.uploading {
    opacity: 0.6;
    pointer-events: none;
}

.drop-icon {
    font-size: 22px;
    line-height: 1;
}

.drop-label {
    color: #aaa;
    font-size: var(--font-size-sm);
}

.drop-browse {
    color: var(--color-secondary);
    text-decoration: underline;
    cursor: pointer;
}

.image-file-input {
    display: none;
}

/* Upload progress bar */
.image-upload-progress {
    width: 100%;
    height: 4px;
    background: var(--color-border);
    border-radius: 2px;
    overflow: hidden;
    margin-top: var(--spacing-xs);
}

.image-upload-progress-fill {
    height: 100%;
    background: var(--color-secondary);
    border-radius: 2px;
    transition: width 0.2s ease;
    width: 0%;
}

/* Distribution Tracker Styles */
.distribution-tracker {
    background: transparent;
    border: none;
    padding: 0;
    margin-bottom: var(--spacing-lg);
}

/* Hide tracker title — header already labels the sidebar */
.tracker-title {
    display: none;
}

.tracker-description {
    color: #999;
    font-size: var(--font-size-sm);
    margin: 0 0 var(--spacing-lg) 0;
    line-height: 1.5;
    text-align: center;
}

.distribution-stats {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.distribution-stats .stat-item {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 2px var(--spacing-md);
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    transition: all var(--transition-speed);
}

.choice-label {
    color: var(--color-secondary);
    font-weight: 600;
    font-size: var(--font-size-sm);
    flex-shrink: 0;
}

.choice-count {
    color: var(--color-secondary);
    font-weight: bold;
    font-size: var(--font-size-md);
}

.choice-percentage {
    color: #999;
    font-size: var(--font-size-sm);
    margin-left: auto;
}

/* Answer Distribution flash on checkbox change */
@keyframes distFlash {
    0%   { background: transparent; }
    25%  { background: rgba(255, 255, 255, 0.18); box-shadow: 0 0 10px rgba(255, 255, 255, 0.25); }
    100% { background: transparent; box-shadow: none; }
}

.distribution-tracker.dist-flash {
    animation: distFlash 0.55s ease-out forwards;
    border-radius: var(--border-radius);
}

/* Per-row flash when an answer is checked as correct */
@keyframes answerRowFlash {
    0%   { background: transparent; }
    20%  { background: rgba(255, 255, 255, 0.14); box-shadow: 0 0 8px rgba(255, 255, 255, 0.2); }
    100% { background: transparent; box-shadow: none; }
}

.answer-row-wrapper.answer-row-flash {
    animation: answerRowFlash 0.5s ease-out forwards;
    border-radius: var(--border-radius);
}

/* ── Answer Type Distribution tracker ───────────────────────────────── */
.type-distribution-tracker {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

.type-dist-title {
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    font-weight: 600;
    text-align: center;
    margin: 0 0 var(--spacing-md) 0;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.type-distribution-stats {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.type-stat-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--color-border);
    border-left-width: 3px;
    border-radius: var(--border-radius);
    transition: opacity var(--transition-speed);
}

.type-stat-row.type-stat-zero {
    opacity: 0.35;
}

.type-stat-label {
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    font-weight: 500;
}

.type-stat-count {
    color: var(--color-secondary);
    font-size: var(--font-size-md);
    font-weight: 700;
    min-width: 24px;
    text-align: right;
}

/* ── Total Questions tracker ─────────────────────────────────────────── */
.total-questions-tracker {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

.total-questions-total-box {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-sm);
}

.total-questions-total-label {
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.total-questions-total-count {
    color: var(--color-secondary);
    font-size: var(--font-size-md);
    font-weight: 700;
    min-width: 24px;
    text-align: right;
}

.total-questions-sections {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

/* ── Help Stats tracker ──────────────────────────────────────────── */
.help-stats-tracker {
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
}

.help-stats-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.help-stat-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    transition: opacity var(--transition-speed);
}

.help-stat-card.help-stat-card--empty {
    opacity: 0.35;
}

.help-stat-label {
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    font-weight: 500;
}

.help-stat-right {
    display: flex;
    align-items: baseline;
    gap: 3px;
}

.help-stat-count {
    font-size: var(--font-size-md);
    font-weight: 700;
    min-width: 20px;
    text-align: right;
    color: var(--color-secondary);
    transition: color var(--transition-speed);
}

.help-stat-total {
    color: var(--color-secondary);
    font-size: 10px;
    opacity: 0.55;
    white-space: nowrap;
}

/* Visual indicators for distribution balance */
.distribution-stats .stat-item.high-usage {
    border-color: #ff9800;
    background: rgba(255, 152, 0, 0.1);
}

.distribution-stats .stat-item.high-usage .choice-label,
.distribution-stats .stat-item.high-usage .choice-count {
    color: #ff9800;
}

.distribution-stats .stat-item.low-usage {
    border-color: #f44336;
    background: rgba(244, 67, 54, 0.1);
}

.distribution-stats .stat-item.low-usage .choice-label,
.distribution-stats .stat-item.low-usage .choice-count {
    color: #f44336;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .create-set-wrapper {
        flex-direction: column;
        margin-left: 0;
    }
    
    .sidebar-container {
        width: 100%;
        height: 200px;
        border-right: none;
        border-bottom: 1px solid var(--color-secondary);
        padding-right: 0;
        padding-bottom: var(--spacing-lg);
        position: static;
    }
    
    .sidebar-content {
        max-height: 150px;
    }
    
    .questions-sidebar {
        grid-template-columns: repeat(auto-fit, minmax(60px, 1fr));
        gap: var(--spacing-xs);
    }
    
    .sidebar-number-box {
        min-height: 32px;
        font-size: var(--font-size-xs);
    }
    
    .dist-sidebar-container {
        position: static;
        width: 100%;
        height: auto;
        border-left: none;
        border-top: 1px solid var(--color-secondary);
    }

    .create-set-wrapper {
        margin-right: 0;
    }
    
    .distribution-tracker {
        margin-bottom: var(--spacing-lg);
    }
    
    .distribution-stats {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-sm);
    }
    
    .distribution-stats .stat-item {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
        text-align: left;
    }
    
    .choice-label {
        margin-bottom: 0;
    }
    
    .choice-percentage {
        margin-top: 0;
        margin-left: var(--spacing-xs);
    }
}

@media (max-width: 768px) {
    .sidebar-container {
        height: 150px;
    }
    
    .sidebar-content {
        max-height: 100px;
    }
    
    .questions-sidebar {
        grid-template-columns: repeat(auto-fit, minmax(50px, 1fr));
    }
    
    .sidebar-number-box {
        min-height: 28px;
        font-size: 10px;
    }
    
    .distribution-stats {
        grid-template-columns: 1fr;
    }
}

/* ── Matching question ──────────────────────────────────────────────── */
.matching-headers {
    display: grid;
    grid-template-columns: 28px 1fr 1fr 28px;
    gap: var(--spacing-sm);
    padding: var(--spacing-xs) 0;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: var(--spacing-xs);
}

.matching-col-header {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: #999;
    text-align: center;
}

.matching-letter-spacer,
.matching-col-spacer {
    /* spacers to align with letter label and delete button */
}

.matching-pairs {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.matching-pair-row {
    display: grid;
    grid-template-columns: 28px 1fr 1fr 28px;
    gap: var(--spacing-sm);
    align-items: center;
}

.matching-row-letter {
    font-weight: 700;
    font-size: var(--font-size-sm);
    color: var(--color-secondary);
    text-align: center;
}

.matching-pair-row .form-input {
    padding: 6px var(--spacing-sm);
    font-size: var(--font-size-sm);
}

.matching-remove-row {
    font-size: 11px;
    padding: 4px 6px;
    opacity: 0.6;
    transition: opacity var(--transition-speed);
}

.matching-remove-row:hover {
    opacity: 1;
}

.btn-add-match-row {
    font-size: var(--font-size-sm);
    padding: 5px var(--spacing-md);
    margin-top: var(--spacing-xs);
}

/* ── Categorize question ─────────────────────────────────────────────── */
.categorize-section-label {
    font-size: var(--font-size-sm);
    font-weight: 700;
    color: var(--color-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin: var(--spacing-md) 0 var(--spacing-xs);
}

.categorize-section-label--items {
    margin-top: var(--spacing-lg);
}

.categorize-categories {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-xs);
}

.category-row {
    display: grid;
    grid-template-columns: 1fr 28px;
    gap: var(--spacing-sm);
    align-items: center;
}

.category-input {
    padding: 6px var(--spacing-sm);
    font-size: var(--font-size-sm);
}

.categorize-items {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-xs);
}

.categorize-item-row {
    display: grid;
    grid-template-columns: 24px 1fr 160px 28px;
    gap: var(--spacing-sm);
    align-items: center;
}

.categorize-item-num {
    font-size: var(--font-size-sm);
    font-weight: 700;
    color: var(--color-secondary);
    text-align: center;
}

.categorize-item-input,
.categorize-item-category {
    padding: 6px var(--spacing-sm);
    font-size: var(--font-size-sm);
}

@media (max-width: 600px) {
    .categorize-item-row {
        grid-template-columns: 20px 1fr 28px;
        grid-template-rows: auto auto;
    }
    .categorize-item-category {
        grid-column: 1 / -2;
    }
}

/* ── Move-to-section button and dropdown ────────────────────────────── */
.move-section-wrapper {
    position: relative;
    display: inline-flex;
}

.btn-move-section {
    background: none;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    font-size: var(--font-size-md);
    padding: 3px 7px;
    line-height: 1;
    transition: color var(--transition-speed), border-color var(--transition-speed);
}

.btn-move-section:hover {
    color: var(--color-secondary);
    border-color: var(--color-secondary);
}

.move-section-dropdown {
    position: absolute;
    top: calc(100% + 4px);
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-active);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    min-width: 160px;
    z-index: 20;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.45);
    overflow: hidden;
}

.move-section-option {
    display: block;
    width: 100%;
    background: none;
    border: none;
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    padding: var(--spacing-xs) var(--spacing-md);
    text-align: left;
    cursor: pointer;
    transition: background var(--transition-speed);
}

.move-section-option:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.08);
}

.move-section-option.current-section {
    color: #888;
    font-style: italic;
    cursor: default;
}

/* ── Section blocks ──────────────────────────────────────────────────── */
.section-block {
    margin-bottom: var(--spacing-xl);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-md) var(--spacing-lg) var(--spacing-lg);
    background: rgba(255, 255, 255, 0.02);
}

.section-header-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--color-border);
}

.section-header-input {
    flex: 1;
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: var(--color-secondary);
    background: transparent;
    border: none;
    border-bottom: 1px dashed transparent;
    padding: 4px 0;
    transition: border-color var(--transition-speed);
}

.section-header-input:focus {
    outline: none;
    border-bottom-color: var(--color-border);
}

.section-header-input::placeholder {
    color: rgba(255, 255, 255, 0.3);
    font-weight: 400;
}

.btn-delete-section {
    background: none;
    border: 1px solid transparent;
    color: rgba(255, 255, 255, 0.4);
    cursor: pointer;
    font-size: var(--font-size-md);
    padding: 4px 8px;
    border-radius: var(--border-radius);
    transition: color var(--transition-speed), border-color var(--transition-speed);
    flex-shrink: 0;
}

.btn-delete-section:hover {
    color: #f44336;
    border-color: #f44336;
}

/* Unnamed section error state — shown when user tries to save with un-renamed sections */
.section-block.section-header--unnamed {
    border-color: #f44336;
    box-shadow: 0 0 0 2px rgba(244, 67, 54, 0.25);
    animation: section-shake 0.35s ease;
}

.section-block.section-header--unnamed .section-header-input {
    color: #f44336;
}

@keyframes section-shake {
    0%, 100% { transform: translateX(0); }
    20%       { transform: translateX(-6px); }
    40%       { transform: translateX(6px); }
    60%       { transform: translateX(-4px); }
    80%       { transform: translateX(4px); }
}

.section-questions {
    display: flex;
    flex-direction: column;
    gap: 0;
}

/* Section-level add question button — less prominent than a top-level action */
.section-add-btn-container {
    margin-top: var(--spacing-md);
    margin-bottom: 0;
}

/* "Add Section" button — sits below all section blocks */
.add-section-btn {
    min-width: 140px;
}

/* Quick Jump sidebar — section labels and dividers */
.sidebar-section-label {
    grid-column: 1 / -1;
    font-size: 10px;
    color: #888;
    padding: var(--spacing-xs) 2px 2px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-top: var(--spacing-xs);
}

.sidebar-section-divider {
    grid-column: 1 / -1;
    height: 1px;
    background: var(--color-border);
    margin: 2px 0 var(--spacing-xs);
}

/* ── Reorder Question ──────────────────────────────────────────────────────── */
.reorder-headers {
    display: grid;
    grid-template-columns: 80px 1fr 32px;
    gap: var(--spacing-sm);
    padding: 0 var(--spacing-xs);
    margin-top: var(--spacing-md);
}

.reorder-col-header {
    font-size: var(--font-size-xs);
    font-weight: 600;
    color: var(--color-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.reorder-col-spacer { width: 32px; }

.reorder-items {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-xs);
}

.reorder-item-row {
    display: grid;
    grid-template-columns: 80px 1fr 32px;
    gap: var(--spacing-sm);
    align-items: center;
}

.reorder-order-select {
    background: var(--color-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-secondary);
    padding: var(--spacing-xs);
    font-size: var(--font-size-sm);
    cursor: pointer;
    width: 70px;
}

/* ── Highlight Fill Question ──────────────────────────────────────────────── */
.highlight-fill-instruction {
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    margin: 0 0 var(--spacing-xs) 0;
    opacity: 0.8;
}

.highlight-fill-toolbar {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.highlight-fill-mark-btn,
.highlight-fill-clear-btn {
    font-size: var(--font-size-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
}

.highlight-fill-preview-label {
    font-size: var(--font-size-xs);
    font-weight: 600;
    color: var(--color-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin: var(--spacing-sm) 0 var(--spacing-xs) 0;
}

.highlight-fill-preview {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--color-secondary);
    font-size: var(--font-size-md);
    line-height: 1.7;
    min-height: 40px;
}

.highlight-blank-preview {
    background: rgba(255, 193, 7, 0.25);
    border-bottom: 2px solid #ffc107;
    border-radius: 2px;
    padding: 0 3px;
    color: #ffc107;
    font-weight: 600;
}

.highlight-fill-empty {
    color: var(--color-secondary);
    opacity: 0.4;
    font-style: italic;
}

/* ── Chart question (create-set editor) ─────────────────────────────── */
.chart-instruction {
    font-size: var(--font-size-sm);
    color: #999;
    margin: 0 0 var(--spacing-md);
    line-height: 1.5;
}

.chart-editor-wrapper {
    overflow-x: auto;
    margin-bottom: var(--spacing-sm);
}

.chart-editor-table {
    border-collapse: collapse;
    min-width: 100%;
}

.chart-cell {
    border: 1px solid var(--color-border);
    padding: 0;
    min-width: 100px;
    position: relative;
    background: rgba(255,255,255,0.03);
    cursor: pointer;
    transition: background var(--transition-speed);
}

.chart-cell:hover {
    background: rgba(255,255,255,0.07);
}

.chart-cell-input {
    width: 100%;
    background: transparent;
    border: none;
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    padding: var(--spacing-sm) 24px var(--spacing-sm) var(--spacing-sm);
    outline: none;
    cursor: text;
    box-sizing: border-box;
}

.chart-cell-toggle-btn {
    position: absolute;
    top: 2px;
    right: 2px;
    width: 18px;
    height: 18px;
    padding: 0;
    font-size: 10px;
    line-height: 1;
    border: none;
    border-radius: 3px;
    background: rgba(255,255,255,0.12);
    color: var(--color-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.15s;
    z-index: 2;
}

.chart-cell:hover .chart-cell-toggle-btn,
.chart-cell-blank .chart-cell-toggle-btn {
    opacity: 1;
}

.chart-cell-blank .chart-cell-toggle-btn {
    background: rgba(244, 67, 54, 0.3);
    color: #f44336;
}

/* Legacy overlay – kept for any old markup, hidden */
.chart-cell-overlay {
    display: none;
    position: absolute;
    inset: 0;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-xs);
    font-weight: 600;
    pointer-events: none;
}

.chart-cell-blank {
    background: rgba(244, 67, 54, 0.12);
    border-color: rgba(244, 67, 54, 0.5);
}

.chart-cell-blank .chart-cell-input {
    opacity: 0.3;
}

.chart-cell-blank .chart-cell-overlay {
    display: flex;
    color: #f44336;
}

.chart-editor-btns {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    margin-top: var(--spacing-sm);
}

.btn-chart-remove {
    opacity: 0.7;
}

.btn-chart-remove:hover {
    opacity: 1;
}

/* ── List question (create-set editor) ──────────────────────────────── */
.list-answer-label {
    margin-top: var(--spacing-md);
}

.list-instruction {
    font-size: var(--font-size-sm);
    color: #999;
    margin: 2px 0 var(--spacing-sm);
    line-height: 1.4;
}

/* ── Chart question (study mode) ────────────────────────────────────── */
.study-chart-wrapper {
    overflow-x: auto;
    margin-bottom: var(--spacing-lg);
}

.study-chart-table {
    border-collapse: collapse;
    min-width: 100%;
}

.study-chart-cell {
    border: 1px solid var(--color-border);
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: var(--font-size-sm);
    color: var(--color-secondary);
    min-width: 90px;
    text-align: center;
}

.study-chart-cell-filled {
    background: rgba(255,255,255,0.03);
}

.study-chart-cell-blank {
    background: rgba(33,150,243,0.08);
    border-color: rgba(33,150,243,0.4);
    padding: 4px;
}

.study-chart-input {
    width: 100%;
    background: transparent;
    border: none;
    border-bottom: 2px solid var(--color-border);
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    padding: 2px 4px;
    text-align: center;
    outline: none;
    box-sizing: border-box;
    transition: border-color 0.2s;
}

.study-chart-input:focus {
    border-bottom-color: #2196F3;
}

/* ── List question (study mode) ─────────────────────────────────────── */
.list-study-input-wrapper {
    margin-bottom: var(--spacing-lg);
}

.list-study-label {
    color: #999;
    font-size: var(--font-size-sm);
    margin: 0 0 var(--spacing-sm);
}

.list-study-textarea {
    width: 100%;
    resize: vertical;
    box-sizing: border-box;
}

/* ── Long Answer / Draw question type — criteria list ────────────────── */
.criteria-label {
    margin-top: var(--spacing-sm);
}

.criteria-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.criterion-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.criterion-bullet {
    color: var(--color-text-muted, #aaa);
    font-size: 1.1rem;
    flex-shrink: 0;
    line-height: 1;
}

.criterion-input {
    flex: 1;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: var(--color-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
    font-family: inherit;
    transition: border-color 0.2s ease;
}

.criterion-input:focus {
    outline: none;
    border-color: var(--color-accent, #4CAF50);
}

.btn-remove-criterion {
    background: none;
    border: none;
    color: var(--color-text-muted, #aaa);
    cursor: pointer;
    font-size: 0.85rem;
    padding: 2px 6px;
    border-radius: var(--border-radius);
    transition: color 0.2s ease;
    flex-shrink: 0;
}

.btn-remove-criterion:hover {
    color: #f44336;
}

.add-criterion-btn {
    align-self: flex-start;
    font-size: var(--font-size-sm);
    padding: var(--spacing-xs) var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

.draw-image-note {
    color: var(--color-text-muted, #aaa);
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-sm);
    margin-bottom: var(--spacing-xs);
    font-style: italic;
}