/* frontend/features/english-writing-practice/style.css */
/* Enhanced English Writing Practice Styles */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border-color: #e5e7eb;
    --border-light: #f3f4f6;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --transition-fast: 150ms ease;
    --transition-normal: 300ms ease;
    --transition-slow: 500ms ease;
}

/* Dark mode variables (optional) */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #1f2937;
        --bg-secondary: #111827;
        --bg-tertiary: #030712;
        --text-primary: #f9fafb;
        --text-secondary: #d1d5db;
        --text-tertiary: #9ca3af;
        --border-color: #374151;
        --border-light: #1f2937;
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: var(--text-primary);
    line-height: 1.6;
}

.app-container {
    max-width: 1400px;
    margin: 0 auto;
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    animation: fadeIn var(--transition-slow);
}

/* Header */
.app-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 2rem;
    text-align: center;
}

.app-header h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.app-header p {
    font-size: 1.1rem;
    opacity: 0.95;
}

/* Setup Section */
.setup-section {
    padding: 2rem;
}

/* Tab Navigation */
.scenario-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.tab-btn {
    background: none;
    border: none;
    padding: 1rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    position: relative;
    white-space: nowrap;
    transition: all var(--transition-normal);
}

.tab-btn:hover {
    color: var(--primary-color);
    background: var(--bg-secondary);
}

.tab-btn.active {
    color: var(--primary-color);
    background: var(--bg-secondary);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-color);
    animation: slideIn var(--transition-normal);
}

.tab-content {
    display: none;
    animation: fadeInUp var(--transition-normal);
}

.tab-content.active {
    display: block;
}

/* Preset Scenarios */
.scenario-presets {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.preset-card {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.preset-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.preset-card.selected {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05) 0%, rgba(99, 102, 241, 0.1) 100%);
}

.preset-icon {
    font-size: 2.5rem;
    margin-bottom: 0.75rem;
    display: block;
}

.preset-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.preset-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.preset-badge {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    background: var(--success-color);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
}

/* Quick Start Options */
.quick-start-section {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-top: 2rem;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.form-group select {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: var(--bg-primary);
    transition: all var(--transition-normal);
}

.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* Difficulty Selector */
.difficulty-selector {
    display: flex;
    gap: 0.5rem;
}

.difficulty-btn {
    flex: 1;
    padding: 0.75rem;
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-normal);
}

.difficulty-btn:hover {
    border-color: var(--primary-light);
    color: var(--primary-color);
}

.difficulty-btn.selected {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

/* Start Button */
.start-btn {
    width: 100%;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    border-radius: var(--radius-lg);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.start-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

/* Practice Section */
.practice-section {
    display: none;
    flex-direction: column;
    height: calc(100vh - 40px);
    max-height: 900px;
}

.practice-header {
    background: var(--bg-secondary);
    padding: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 2px solid var(--border-color);
}

.scenario-info {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.info-badge {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
}

.custom-badge {
    background: linear-gradient(135deg, #fbbf24, #f59e0b);
    color: white;
}

.practice-stats {
    display: flex;
    gap: 2rem;
}

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

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
}

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

/* Practice Content */
.practice-content {
    flex: 1;
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 0;
    overflow: hidden;
}

.chat-area {
    display: flex;
    flex-direction: column;
    background: var(--bg-primary);
    border-right: 2px solid var(--border-color);
}

/* Messages Container */
.messages-container {
    flex: 1;
    padding: 1.5rem;
    overflow-y: auto;
    scroll-behavior: smooth;
}

.message {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    animation: fadeInUp var(--transition-normal);
}

.message.user-message {
    justify-content: flex-end;
}

.message-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    background: var(--bg-tertiary);
    flex-shrink: 0;
}

.message-bubble {
    max-width: 70%;
    padding: 1rem;
    border-radius: var(--radius-lg);
    background: var(--bg-secondary);
}

.user-message .message-bubble {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
}

.message-role {
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    opacity: 0.8;
}

.message-text {
    line-height: 1.6;
}

/* Suggested Responses */
.suggested-responses {
    padding: 1rem;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
}

.suggestions-header {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.suggestions-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.suggestion-chip {
    padding: 0.5rem 1rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.suggestion-chip:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: scale(1.05);
}

/* Input Area */
.input-area {
    padding: 1rem;
    background: var(--bg-secondary);
    border-top: 2px solid var(--border-color);
}

.input-wrapper {
    display: flex;
    gap: 0.75rem;
    align-items: flex-end;
}

.input-field {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    resize: none;
    transition: all var(--transition-normal);
    max-height: 120px;
}

.input-field:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.send-btn {
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-normal);
    white-space: nowrap;
}

.send-btn:hover {
    background: var(--primary-dark);
    transform: scale(1.05);
}

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

.input-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: 0.5rem;
}

.action-btn {
    padding: 0.5rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1.2rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.action-btn:hover {
    background: var(--primary-color);
    border-color: var(--primary-color);
    transform: scale(1.1);
}

.action-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
    transform: none;
}

/* Feedback Panel */
.feedback-panel {
    background: var(--bg-secondary);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.feedback-header {
    padding: 1.5rem;
    background: var(--bg-primary);
    border-bottom: 2px solid var(--border-color);
}

.feedback-header h3 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin: 0;
    font-size: 1.1rem;
}

.feedback-content {
    flex: 1;
    padding: 1.5rem;
    overflow-y: auto;
}

.feedback-empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    color: var(--text-secondary);
}

.feedback-empty-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.feedback-section {
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
}

.feedback-section h4 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.status-indicator {
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-weight: 500;
}

.status-indicator.correct {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.status-indicator.incorrect {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

.status-indicator.warning {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
}

.error-list, .tips-list {
    margin-top: 0.5rem;
    padding-left: 1.5rem;
}

.error-list li, .tips-list li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.alternatives {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.alternative-item {
    padding: 0.75rem;
    background: var(--bg-secondary);
    border-left: 3px solid var(--primary-color);
    border-radius: var(--radius-md);
    font-style: italic;
}

.explanation {
    color: var(--text-secondary);
    line-height: 1.7;
}

.score-indicators {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 1rem;
}

.score-item {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.score-label {
    min-width: 60px;
    font-weight: 500;
}

.score-bar {
    flex: 1;
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
}

.score-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--primary-light) 100%);
    transition: width var(--transition-slow);
}

.score-value {
    min-width: 60px;
    text-align: right;
    font-weight: 600;
    color: var(--primary-color);
}

/* Progress Section */
.progress-section {
    padding: 1rem 1.5rem;
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
}

.progress-bar {
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--primary-light) 100%);
    transition: width var(--transition-slow);
}

.progress-text {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    background: var(--bg-primary);
}

.btn-primary, .btn-secondary {
    flex: 1;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-normal);
    border: none;
    font-size: 0.95rem;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: scale(1.02);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-tertiary);
    border-color: var(--primary-light);
}

/* Custom Scenario Builder */
.custom-scenario-builder {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: 2rem;
}

.scenario-input-section textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    resize: vertical;
    transition: all var(--transition-normal);
}

.scenario-input-section textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.char-counter {
    text-align: right;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

.scenario-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.checkbox-group {
    display: grid;
    gap: 0.75rem;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    transition: background var(--transition-fast);
}

.checkbox-label:hover {
    background: var(--bg-tertiary);
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.generate-btn {
    width: 100%;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border: none;
    border-radius: var(--radius-lg);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: all var(--transition-normal);
}

.generate-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* Generated Scenario Preview */
.generated-scenario-preview {
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--bg-primary);
    border: 2px solid var(--primary-color);
    border-radius: var(--radius-lg);
    animation: fadeInUp var(--transition-normal);
}

.scenario-details {
    display: grid;
    gap: 1rem;
    margin: 1rem 0 1.5rem;
}

.detail-item {
    display: flex;
    gap: 0.5rem;
}

.detail-item strong {
    color: var(--text-secondary);
    min-width: 100px;
}

.keyword-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.keyword-tag {
    padding: 0.25rem 0.75rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    color: var(--primary-color);
}

.preview-actions {
    display: flex;
    gap: 1rem;
}

/* Saved Scenarios */
.saved-scenarios-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.saved-scenario-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    transition: all var(--transition-normal);
}

.saved-scenario-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.scenario-card-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 1rem;
}

.scenario-card-header h4 {
    flex: 1;
    color: var(--text-primary);
    margin: 0;
}

.delete-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.delete-btn:hover {
    background: var(--danger-color);
    color: white;
}

.scenario-card-desc {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.5;
    margin-bottom: 1rem;
}

.scenario-card-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.scenario-card-tags {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
    min-height: 24px;
}

.scenario-card-tags .tag {
    padding: 0.125rem 0.5rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    color: var(--primary-color);
}

.scenario-card-actions {
    display: flex;
    gap: 0.5rem;
}

.btn-primary-small, .btn-secondary-small {
    flex: 1;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-normal);
    border: none;
}

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

.btn-primary-small:hover {
    background: var(--primary-dark);
}

.btn-secondary-small {
    background: var(--bg-primary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary-small:hover {
    background: var(--bg-tertiary);
}

/* Achievement Notification */
.achievement {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0);
    background: white;
    border-radius: var(--radius-xl);
    padding: 2rem;
    box-shadow: var(--shadow-xl);
    z-index: 10000;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    transition: transform var(--transition-normal);
}

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

.achievement-icon {
    font-size: 3rem;
    animation: bounce 1s infinite;
}

.achievement-content h4 {
    margin-bottom: 0.25rem;
    color: var(--primary-color);
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.loading-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.loading-overlay p {
    color: white;
    margin-top: 1rem;
    font-size: 1.1rem;
}

/* Toast Container */
.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10001;
    pointer-events: none;
}

.toast {
    background: white;
    border-radius: var(--radius-lg);
    padding: 1rem 1.5rem;
    margin-bottom: 0.5rem;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transform: translateX(400px);
    transition: transform var(--transition-normal);
    pointer-events: auto;
    max-width: 400px;
}

.toast.show {
    transform: translateX(0);
}

.toast-success {
    border-left: 4px solid var(--success-color);
}

.toast-warning {
    border-left: 4px solid var(--warning-color);
}

.toast-error {
    border-left: 4px solid var(--danger-color);
}

.toast-info {
    border-left: 4px solid var(--primary-color);
}

.toast-icon {
    font-size: 1.25rem;
}

.toast-message {
    flex: 1;
}

/* Session Summary */
.session-summary {
    padding: 2rem;
    text-align: center;
}

.session-summary h3 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.summary-stats {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
}

.summary-stats .stat {
    text-align: center;
}

.summary-stats .stat-label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.summary-stats .stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
}

.summary-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* Modal */
.scenario-preview-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    padding: 20px;
    animation: fadeIn var(--transition-normal);
}

.modal-content {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    max-width: 600px;
    width: 100%;
    max-height: 80vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    animation: slideInUp var(--transition-normal);
}

.modal-header {
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-bottom: 2px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    margin: 0;
    color: var(--primary-color);
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

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

.modal-body {
    flex: 1;
    padding: 1.5rem;
    overflow-y: auto;
}

.preview-section {
    margin-bottom: 1.5rem;
}

.preview-section strong {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.preview-section p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.preview-section ul {
    padding-left: 1.5rem;
    color: var(--text-secondary);
}

.keyword-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.modal-footer {
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-top: 2px solid var(--border-color);
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
}

/* Mobile Toggle Button */
.toggle-feedback-btn {
    display: none;
    position: fixed;
    right: 20px;
    bottom: 20px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: var(--primary-color);
    color: white;
    border: none;
    box-shadow: var(--shadow-lg);
    cursor: pointer;
    z-index: 999;
    font-size: 1.5rem;
    transition: all var(--transition-normal);
}

.toggle-feedback-btn:hover {
    transform: scale(1.1);
    background: var(--primary-dark);
}

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

@keyframes fadeInUp {
    from { 
        opacity: 0; 
        transform: translateY(20px);
    }
    to { 
        opacity: 1; 
        transform: translateY(0);
    }
}

@keyframes slideIn {
    from { transform: translateX(-20px); }
    to { transform: translateX(0); }
}

@keyframes slideInUp {
    from { transform: translateY(30px); }
    to { transform: translateY(0); }
}

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

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

/* Responsive Design */
@media (max-width: 1200px) {
    .practice-content {
        grid-template-columns: 1fr 350px;
    }
}

@media (max-width: 1024px) {
    .practice-content {
        grid-template-columns: 1fr;
    }
    
    .feedback-panel {
        position: fixed;
        right: 0;
        top: 0;
        height: 100vh;
        width: 400px;
        transform: translateX(100%);
        transition: transform var(--transition-normal);
        z-index: 1000;
        box-shadow: -5px 0 15px rgba(0, 0, 0, 0.1);
    }
    
    .feedback-panel.open {
        transform: translateX(0);
    }
    
    .toggle-feedback-btn {
        display: flex !important;
        align-items: center;
        justify-content: center;
    }
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    
    .app-header {
        padding: 1.5rem 1rem;
    }
    
    .app-header h1 {
        font-size: 1.5rem;
    }
    
    .app-header p {
        font-size: 0.95rem;
    }
    
    .scenario-presets {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: 1rem;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .practice-header {
        flex-direction: column;
        gap: 1rem;
    }
    
    .scenario-info {
        width: 100%;
    }
    
    .practice-stats {
        width: 100%;
        justify-content: space-around;
    }
    
    .message-bubble {
        max-width: 85%;
    }
    
    .feedback-panel {
        width: 100%;
    }
    
    .saved-scenarios-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        max-height: 90vh;
    }
    
    .toast-container {
        left: 10px;
        right: 10px;
    }
    
    .toast {
        max-width: none;
    }
}

@media (max-width: 480px) {
    .scenario-presets {
        grid-template-columns: 1fr;
    }
    
    .difficulty-selector {
        flex-direction: column;
    }
    
    .difficulty-btn {
        width: 100%;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .btn-primary, .btn-secondary {
        width: 100%;
    }
}

/* Print Styles */
@media print {
    .app-header,
    .scenario-tabs,
    .action-buttons,
    .input-area,
    .toggle-feedback-btn {
        display: none !important;
    }
    
    .messages-container {
        max-height: none;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation: none !important;
        transition: none !important;
    }
}

/* Focus Styles */
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Loading States */
.loading {
    position: relative;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

.empty-icon {
    font-size: 3rem;
    display: block;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-hint {
    font-size: 0.875rem;
    margin-top: 0.5rem;
}

/* AI模型选择器样式 */
.model-selector {
    position: relative;
}

.model-selector select {
    width: 100%;
    padding: 0.75rem 1rem;
    background: linear-gradient(145deg, #ffffff, #f9fafb);
    border: 2px solid #e5e7eb;
    border-radius: var(--radius-md);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.model-selector select:hover {
    border-color: var(--primary-color);
    box-shadow: 0 2px 8px rgba(99, 102, 241, 0.2);
}

.model-selector select:focus {
    outline: none;
    border-color: var(--primary-dark);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.model-tooltip {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-top: 5px;
    padding: 12px;
    background: rgba(255, 255, 255, 0.98);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    font-size: 0.875rem;
    color: var(--text-secondary);
    z-index: 100;
    animation: fadeIn var(--transition-normal);
}

.model-tooltip strong {
    color: var(--primary-color);
    display: block;
    margin-bottom: 4px;
}

.model-tooltip small {
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

/* 模型选项样式 */
#aiModelSelect option[data-tier="paid"] {
    background: linear-gradient(90deg, #ffd93d, #ffed4e);
}

#aiModelSelect option[data-default="true"] {
    font-weight: bold;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .model-selector select {
        font-size: 0.95rem;
        padding: 0.65rem 0.9rem;
    }
    
    .model-tooltip {
        font-size: 0.8rem;
    }
}