/* ========================================
   Worksheet Generator Styles - Optimized
   ======================================== */
.worksheet-generator-page {
    width: 100%;
    height: 100%;
    padding: 20px;
    display: flex;
    flex-direction: column;
    background: var(--bg-color);
}

.worksheet-container {
    flex: 1;
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 20px;
    min-height: 0;
}

/* Controls Panel */
.worksheet-controls {
    background: var(--element-bg);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 12px 16px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    height: fit-content;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

.controls-header h2 {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.controls-header p {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.control-group>label {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
}

/* Button Group */
.button-group {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}

.option-btn {
    padding: 7px 14px;
    border: 1.5px solid var(--border-color);
    border-radius: 12px;
    background: var(--bg-color);
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.option-btn:hover {
    border-color: var(--text-secondary);
    background: #fff;
}

.option-btn.active {
    background: var(--text-primary);
    border-color: var(--text-primary);
    color: var(--bg-color);
}

/* Checkbox Group */
.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.checkbox-option {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    padding: 8px 12px;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.checkbox-option:hover {
    background: #fff;
    border-color: var(--text-secondary);
}

.checkbox-option input[type="checkbox"] {
    width: 15px;
    height: 15px;
    accent-color: var(--text-highlight);
    cursor: pointer;
    margin-top: 4px;
}

.checkbox-option span {
    font-size: 0.85rem;
    color: var(--text-primary);
    font-weight: 500;
}

/* Generate Button */
.generate-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 20px;
    background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
    color: #fff;
    border: none;
    border-radius: 12px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 8px;
}

.generate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.15);
}

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

.generate-btn svg {
    stroke: currentColor;
    width: 18px;
    height: 18px;
}

/* Preview Panel */
.worksheet-preview {
    background: var(--element-bg);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-height: 0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

.preview-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 14px;
    background: var(--element-bg);
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
}

.preview-tabs {
    display: flex;
    gap: 6px;
}

.preview-tab {
    padding: 6px 14px;
    border: 1.5px solid transparent;
    border-radius: 12px;
    background: transparent;
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.preview-tab:hover {
    background: var(--bg-color);
}

.preview-tab.active {
    background: var(--text-primary);
    color: var(--bg-color);
}

.export-buttons {
    display: flex;
    gap: 6px;
}

.export-btn {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 6px 12px;
    border: 1.5px solid var(--border-color);
    border-radius: 12px;
    background: var(--bg-color);
    color: var(--text-secondary);
    font-size: 0.75rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.export-btn:hover:not(:disabled) {
    border-color: var(--text-highlight);
    color: var(--text-highlight);
    background: #fff;
}

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

.export-btn svg {
    stroke: currentColor;
    width: 14px;
    height: 14px;
}

.preview-content {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
}

.preview-placeholder {
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    color: var(--text-muted);
}

.preview-placeholder svg {
    opacity: 0.25;
    width: 40px;
    height: 40px;
}

.preview-placeholder p {
    font-size: 0.9rem;
    text-align: center;
}

/* ===== Worksheet Paper Styles ===== */
.worksheet-paper {
    max-width: 680px;
    margin: 0 auto;
}

.worksheet-header {
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--text-primary);
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.header-top h1 {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.worksheet-id-badge {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--text-secondary);
    background: var(--element-bg);
    padding: 4px 10px;
    border-radius: 8px;
    font-family: 'SF Mono', monospace;
    border: 1px solid var(--border-color);
}

.header-fields {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
    margin-bottom: 12px;
}

.field-group {
    display: flex;
    align-items: baseline;
    gap: 6px;
}

.field-label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.field-line {
    width: 140px;
    border-bottom: 1px solid var(--text-primary);
}

.field-line.short {
    width: 40px;
}

.field-value {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-primary);
}

.score-total {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.instructions {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* Questions Grid */
.questions-grid {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.question-row {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 10px;
    background: var(--element-bg);
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.q-num {
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--text-highlight);
    min-width: 18px;
}

.q-equation {
    font-size: 0.8rem;
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
    color: var(--text-primary);
    letter-spacing: 0.01em;
}

/* Equation Elements */
.coef {
    display: inline-block;
    min-width: 14px;
    text-align: center;
    margin-right: 1px;
    font-weight: 700;
}

.coef.blank {
    border-bottom: 2px solid var(--text-primary);
    color: transparent;
    margin-bottom: -2px;
}

.coef.filled {
    color: #047857;
}

.formula {
    font-weight: 500;
}

.formula sub {
    font-size: 0.7em;
}

.plus {
    margin: 0 4px;
    color: var(--text-secondary);
    font-weight: 500;
}

.arrow {
    margin: 0 8px;
    color: var(--text-primary);
    font-weight: 500;
}

.worksheet-footer {
    margin-top: 24px;
    padding-top: 12px;
    border-top: 1px solid var(--border-color);
    text-align: center;
    font-size: 0.7rem;
    color: var(--text-muted);
}

/* Answer Key Specific */
.answer-key .question-row {
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
    border-color: #a7f3d0;
}

.answer-key .q-num {
    color: #047857;
}

.answer-key .coef.filled {
    color: #047857;
    font-weight: 700;
}

/* ===== Practice Mode Styles ===== */
.practice-mode .worksheet-header {
    border-bottom-color: #6366f1;
}

.practice-mode .header-top h1 {
    color: #4f46e5;
}

/* Coefficient Input */
.coef-input {
    width: 30px;
    height: 22px;
    text-align: center;
    font-size: 0.75rem;
    font-weight: 700;
    font-family: 'SF Mono', monospace;
    border: 1.5px solid #cbd5e1;
    border-radius: 8px;
    background: #fff;
    color: var(--text-primary);
    outline: none;
    transition: all 0.2s ease;
    margin-right: 1px;
    -moz-appearance: textfield;
    appearance: textfield;
}

.coef-input::-webkit-outer-spin-button,
.coef-input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.coef-input:focus {
    border-color: #6366f1;
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

.coef-input.correct {
    border-color: #10b981;
    background: #ecfdf5;
    color: #047857;
}

.coef-input.incorrect {
    border-color: #ef4444;
    background: #fef2f2;
    color: #dc2626;
}

/* Question Row Results */
.question-row.correct {
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
    border-color: #a7f3d0;
}

.question-row.incorrect {
    background: linear-gradient(135deg, #fef2f2 0%, #fee2e2 100%);
    border-color: #fca5a5;
}

.result-icon {
    font-size: 1.2rem;
    font-weight: 700;
    margin-left: auto;
}

.question-row.correct .result-icon {
    color: #10b981;
}

.question-row.incorrect .result-icon {
    color: #ef4444;
}

/* Practice Actions */
.practice-actions {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-top: 20px;
    padding-top: 16px;
    border-top: 1px dashed var(--border-color);
}

.check-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: linear-gradient(135deg, #6366f1 0%, #4f46e5 100%);
    color: #fff;
    border: none;
    border-radius: 12px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.check-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

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

.check-btn svg {
    stroke: currentColor;
}

/* Score Display */
.score-display {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--element-bg);
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.score-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.score-value {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
}

.score-value.perfect {
    color: #10b981;
}

/* NEW STYLES: Navigation and Footer Toggle */
.top-right-nav {
    display: flex;
    justify-content: flex-end;
    gap: 8px;
    margin-bottom: 0;
}

.controls-footer {
    margin-top: auto;
    padding-top: 20px;
}

.lang-toggle-minimal {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    background: transparent;
    border: 1px solid transparent;
    border-radius: 12px;
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    width: 100%;
    justify-content: flex-start;
}

.lang-toggle-minimal:hover {
    background: var(--element-bg);
    color: var(--text-primary);
    border-color: var(--border-color);
}

/* =========================================
   New UI Elements (Subtitles, Trust Text)
   ========================================= */
.checkbox-text-wrapper {
    display: flex;
    flex-direction: column;
    margin-left: 2px;
}

.checkbox-subtitle {
    display: block;
    font-size: 0.7rem;
    color: var(--text-muted);
    font-family: 'SF Mono', monospace;
    margin-top: 2px;
    opacity: 0.8;
    line-height: 1.2;
}

.trust-text {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-align: center;
    margin-top: 12px;
    line-height: 1.4;
    padding: 0 4px;
    opacity: 0.8;
}

.preview-summary-bar {
    background: #f8fafc;
    color: #475569;
    font-size: 0.8rem;
    font-weight: 600;
    padding: 10px 16px;
    border-radius: 12px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
    border: 1px solid #e2e8f0;
}

.preview-summary-icon {
    color: #64748b;
    width: 16px;
    height: 16px;
}