/* ===========================
   Python Learning App Styles
   =========================== */

/* CSS Variables - Light Mode (Default) */
:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --primary-light: #dbeafe;
    --success-color: #10b981;
    --success-hover: #059669;
    --success-light: #d1fae5;
    --secondary-color: #6b7280;
    --secondary-hover: #4b5563;
    --error-color: #ef4444;
    --warning-color: #f59e0b;

    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --sidebar-bg: #f1f5f9;
    --border-color: #e2e8f0;
    --hover-bg: #f0f9ff;

    --text-primary: #1e293b;
    --text-secondary: #475569;
    --text-muted: #64748b;

    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', Menlo, Monaco, 'Courier New', monospace;

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);

    --transition: all 0.2s ease;
    --transition-slow: all 0.3s ease;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --primary-color: #60a5fa;
    --primary-hover: #3b82f6;
    --primary-light: #1e3a5f;
    --success-color: #34d399;
    --success-hover: #10b981;
    --success-light: #064e3b;
    --secondary-color: #9ca3af;
    --secondary-hover: #d1d5db;
    --error-color: #f87171;
    --warning-color: #fbbf24;

    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --sidebar-bg: #1e293b;
    --border-color: #334155;
    --hover-bg: #334155;

    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -4px rgba(0, 0, 0, 0.4);
}

/* ===========================
   Animations & Keyframes
   =========================== */

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

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

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

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

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

@keyframes shimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}

@keyframes progressFill {
    from { width: 0; }
    to { width: var(--progress-width, 0%); }
}

/* Animation Classes */
.animate-fade-in {
    animation: fadeIn 0.3s ease forwards;
}

.animate-fade-in-up {
    animation: fadeInUp 0.4s ease forwards;
}

.animate-slide-in-left {
    animation: slideInLeft 0.3s ease forwards;
}

.animate-scale-in {
    animation: scaleIn 0.3s ease forwards;
}

/* Reset & Base */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background-color: var(--bg-color);
}

[data-theme="dark"] html,
html[data-theme="dark"] {
    color-scheme: dark;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* App Container */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Page Mode - セクションを独立ページとして表示 */
body.page-mode .sidebar {
    display: none;
}

body.page-mode .search-section,
body.page-mode .welcome-message,
body.page-mode .explanation-card,
body.page-mode .practice-card,
body.page-mode .error-message {
    display: none;
}

body.page-mode .content-area {
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}

body.page-mode .main-content {
    display: block;
}

body.page-mode .dashboard-section,
body.page-mode .glossary-section,
body.page-mode .learning-center-section {
    margin: 0;
    border-radius: 0;
    min-height: auto;
}

/* 用語集をページモードで全体表示 */
body.page-mode .keyword-index-toc {
    max-height: none;
    overflow-y: visible;
}

/* Header */
.header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
}

.logo:hover {
    opacity: 0.8;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.profile-summary {
    cursor: pointer;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.profile-summary:hover {
    background-color: var(--sidebar-bg);
}

.stats-badge {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Main Content */
.main-content {
    display: flex;
    flex: 1;
    max-width: 1400px;
    margin: 0 auto;
    width: 100%;
    padding: 1.5rem;
    gap: 1.5rem;
}

/* Sidebar */
.sidebar {
    width: 280px;
    flex-shrink: 0;
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    height: fit-content;
    max-height: calc(100vh - 120px);
    overflow-y: auto;
}

.sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-header h2 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.sidebar-actions {
    display: flex;
    gap: 0.25rem;
}

/* Hide sidebar close button on desktop (only shown on mobile) */
.sidebar-close-btn {
    display: none;
}

.refresh-btn,
.clear-history-btn {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 0.25rem;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.refresh-btn:hover {
    background-color: var(--sidebar-bg);
    color: var(--primary-color);
}

.clear-history-btn:hover {
    background-color: #fef2f2;
    color: var(--error-color);
}

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

.history-item {
    padding: 0.75rem;
    border-radius: var(--radius-md);
    background: var(--sidebar-bg);
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
}

.history-item:hover {
    border-color: var(--primary-color);
    background: #eff6ff;
}

.history-term {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-primary);
}

.history-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 0.25rem;
    font-size: 0.75rem;
    color: var(--text-muted);
    gap: 0.5rem;
}

.history-time {
    flex-shrink: 0;
}

.history-level {
    background: var(--primary-color);
    color: white;
    padding: 0.125rem 0.5rem;
    border-radius: 9999px;
    font-size: 0.65rem;
    font-weight: 600;
    flex-shrink: 0;
    white-space: nowrap;
}

.history-level.understood {
    background: var(--success-color);
}

.empty-message {
    color: var(--text-muted);
    font-size: 0.875rem;
    text-align: center;
    padding: 1rem;
}

/* Content Area */
.content-area {
    flex: 1;
    min-width: 0;
}

/* Search Section */
.search-section {
    margin-bottom: 1.5rem;
}

.search-box {
    display: flex;
    gap: 0.75rem;
    background: var(--card-bg);
    padding: 1rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.search-box input {
    flex: 1;
    padding: 0.875rem 1rem;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    outline: none;
    transition: var(--transition);
    font-family: var(--font-sans);
}

.search-box input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.search-box input::placeholder {
    color: var(--text-muted);
}

.search-hint {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.75rem;
    padding-left: 0.5rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.875rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font-sans);
    white-space: nowrap;
}

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

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

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

.btn-success:hover:not(:disabled) {
    background: var(--success-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-success:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

.btn-secondary {
    background: var(--sidebar-bg);
    color: var(--text-primary);
    border: none;
}

.btn-secondary:hover:not(:disabled) {
    background: var(--border-color);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-outline:hover:not(:disabled) {
    background: var(--primary-color);
    color: white;
}

.btn-practice {
    background: linear-gradient(135deg, #8b5cf6 0%, #6366f1 100%);
    color: white;
}

.btn-practice:hover:not(:disabled) {
    background: linear-gradient(135deg, #7c3aed 0%, #4f46e5 100%);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-icon {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: rgba(255, 255, 255, 0.8);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    transition: var(--transition);
    line-height: 1;
}

.btn-icon:hover {
    background: rgba(255, 255, 255, 0.1);
    color: white;
}

.btn-loading {
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* Explanation Card */
.explanation-card {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    overflow: hidden;
    animation: fadeInUp 0.4s ease;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.term-title {
    font-size: 1.5rem;
    font-weight: 700;
}

.level-indicator {
    display: flex;
    gap: 0.5rem;
}

.level-badge {
    padding: 0.375rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.8rem;
    font-weight: 700;
    background: rgba(255, 255, 255, 0.25);
    color: rgba(255, 255, 255, 0.85);
    transition: var(--transition);
}

.level-badge.active {
    background: white;
    color: #764ba2;
    box-shadow: var(--shadow-sm);
}

.card-body {
    padding: 1.5rem;
    max-height: 60vh;
    overflow-y: auto;
}

.card-actions {
    display: flex;
    gap: 1rem;
    padding: 1.25rem 1.5rem;
    background: var(--sidebar-bg);
    border-top: 1px solid var(--border-color);
    flex-wrap: wrap;
}

/* Related Keywords */
.related-keywords {
    padding: 1rem 1.5rem;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border-top: 1px solid var(--border-color);
}

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

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

.related-keyword-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.5rem 1rem;
    background: white;
    border: 2px solid var(--primary-color);
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--primary-color);
    cursor: pointer;
    transition: var(--transition);
}

.related-keyword-btn:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.related-keyword-btn.loaded {
    background: var(--success-color);
    border-color: var(--success-color);
    color: white;
    cursor: default;
}

.related-keyword-btn.loaded:hover {
    transform: none;
    box-shadow: none;
}

/* Additional Explanations */
#additional-explanations {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.additional-explanation-card {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 2px solid var(--primary-color);
    overflow: hidden;
}

.additional-explanation-card .card-header {
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
}

.additional-explanation-card .card-body {
    max-height: 50vh;
}

/* Practice Card */
.practice-card {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    overflow: hidden;
    margin-top: 1.5rem;
}

.practice-header {
    background: linear-gradient(135deg, #8b5cf6 0%, #6366f1 100%);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.practice-problem {
    background: var(--sidebar-bg);
    padding: 1.25rem;
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
}

.practice-problem h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.practice-problem p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    line-height: 1.7;
}

.practice-problem code {
    font-family: var(--font-mono);
    background: #e2e8f0;
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.9em;
    color: #7c3aed;
}

.practice-editor {
    margin-bottom: 1.25rem;
}

.practice-editor label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

/* Monaco Editor Container */
.monaco-editor-container {
    width: 100%;
    min-height: 300px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: var(--transition);
}

.monaco-editor-container:focus-within {
    border-color: #8b5cf6;
    box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.1);
}

/* Monaco Editor Custom Theme (to match example code colors) */
.monaco-editor {
    --vscode-editor-background: #1e293b;
    --vscode-editor-foreground: #e2e8f0;
}

/* Legacy code-editor class (kept for compatibility) */
.code-editor {
    width: 100%;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.6;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: #1e293b;
    color: #e2e8f0;
    resize: vertical;
    min-height: 150px;
    transition: var(--transition);
}

.code-editor:focus {
    outline: none;
    border-color: #8b5cf6;
    box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.1);
}

.code-editor::placeholder {
    color: #64748b;
}

.practice-actions {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1.25rem;
    flex-wrap: wrap;
}

.practice-hint,
.practice-answer,
.practice-result {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-md);
    margin-top: 1rem;
}

.practice-hint {
    background: #fef3c7;
    border: 1px solid #f59e0b;
}

.practice-hint h4 {
    color: #92400e;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.practice-hint p {
    color: #78350f;
    margin: 0;
}

.practice-answer {
    background: #f0fdf4;
    border: 1px solid var(--success-color);
}

.practice-answer h4 {
    color: #166534;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.practice-answer pre {
    background: #1e293b;
    border-radius: var(--radius-md);
    padding: 1rem;
    overflow-x: auto;
    margin: 0;
}

.practice-answer pre code {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: #e2e8f0;
    line-height: 1.6;
}

.practice-result {
    background: #eff6ff;
    border: 1px solid var(--primary-color);
}

.practice-result.success {
    background: #f0fdf4;
    border-color: var(--success-color);
}

.practice-result.error {
    background: #fef2f2;
    border-color: var(--error-color);
}

.practice-result h4 {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.practice-result.success h4 {
    color: #166534;
}

.practice-result.error h4 {
    color: #991b1b;
}

.practice-result p {
    margin: 0;
    color: var(--text-secondary);
}

.practice-result .execution-output {
    margin-top: 0.75rem;
}

.practice-result .output-box {
    background: #1e293b;
    color: #e2e8f0;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    margin: 0.5rem 0;
    white-space: pre-wrap;
    word-break: break-all;
}

.practice-result .warning-text {
    color: #f59e0b;
    font-weight: 600;
    margin-top: 0.5rem;
}

.practice-result .auto-understand-notice {
    color: #10b981;
    font-weight: 600;
    margin-top: 0.75rem;
    padding: 0.5rem 0.75rem;
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
    border-radius: var(--radius-md);
    border: 1px solid #10b981;
}

[data-theme="dark"] .practice-result .auto-understand-notice {
    background: linear-gradient(135deg, #064e3b 0%, #065f46 100%);
    color: #6ee7b7;
    border-color: #059669;
}

.practice-result .reference-answer {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 0.5rem;
    font-style: italic;
}

[data-theme="dark"] .practice-result .reference-answer {
    color: #94a3b8;
}

.practice-result .error-details {
    margin-top: 0.75rem;
}

.practice-result .error-details p {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.practice-result .error-box {
    background: #fef2f2;
    border: 1px solid var(--error-color);
    color: #991b1b;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    margin: 0.5rem 0;
    white-space: pre-wrap;
    word-break: break-all;
}

.practice-result .suggestion-box {
    background: #fef3c7;
    border: 1px solid #f59e0b;
    color: #78350f;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    margin: 0.5rem 0;
    line-height: 1.6;
}

/* Monaco Editor Error Highlighting */
.error-line-highlight {
    background-color: rgba(239, 68, 68, 0.1) !important;
    border-left: 3px solid #ef4444 !important;
}

.error-glyph {
    background-color: #ef4444 !important;
    width: 4px !important;
}

/* Markdown Body Styles */
.markdown-body {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-primary);
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4 {
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    font-weight: 600;
    line-height: 1.3;
}

.markdown-body h1 { font-size: 1.75rem; }
.markdown-body h2 { font-size: 1.5rem; }
.markdown-body h3 { font-size: 1.25rem; }
.markdown-body h4 { font-size: 1.1rem; }

.markdown-body p {
    margin-bottom: 1rem;
}

.markdown-body ul,
.markdown-body ol {
    margin-bottom: 1rem;
    padding-left: 1.5rem;
}

.markdown-body li {
    margin-bottom: 0.5rem;
}

.markdown-body code {
    font-family: var(--font-mono);
    background: #f1f5f9;
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.9em;
    color: #e11d48;
}

.markdown-body pre {
    background: #1e293b;
    border-radius: var(--radius-md);
    padding: 1rem 1.25rem;
    overflow-x: auto;
    margin: 1rem 0;
    box-shadow: var(--shadow-sm);
}

.markdown-body pre code {
    background: none;
    padding: 0;
    color: #e2e8f0;
    font-size: 0.875rem;
    line-height: 1.6;
}

.markdown-body blockquote {
    border-left: 4px solid var(--primary-color);
    padding-left: 1rem;
    margin: 1rem 0;
    color: var(--text-secondary);
    font-style: italic;
}

.markdown-body strong {
    font-weight: 600;
    color: var(--text-primary);
}

.markdown-body em {
    font-style: italic;
}

.markdown-body a {
    color: var(--primary-color);
    text-decoration: none;
}

.markdown-body a:hover {
    text-decoration: underline;
}

.markdown-body table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

.markdown-body th,
.markdown-body td {
    border: 1px solid var(--border-color);
    padding: 0.75rem;
    text-align: left;
}

.markdown-body th {
    background: var(--sidebar-bg);
    font-weight: 600;
}

.markdown-body hr {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 1.5rem 0;
}

/* Messages */
.welcome-message,
.success-message,
.error-message {
    text-align: center;
    padding: 3rem;
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.welcome-icon,
.success-icon,
.error-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.welcome-message h2 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.welcome-message p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.example-terms {
    margin-top: 1.5rem;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 0.5rem;
}

.example-terms p {
    color: var(--text-muted);
    margin: 0;
    font-size: 0.875rem;
}

.example-btn {
    padding: 0.5rem 1rem;
    background: var(--sidebar-bg);
    border: 1px solid var(--border-color);
    border-radius: 9999px;
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font-sans);
}

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

.success-message {
    background: linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%);
    border-color: var(--success-color);
}

.success-text {
    font-size: 1.25rem;
    font-weight: 600;
    color: #065f46;
    margin-bottom: 0.5rem;
}

.success-subtext {
    color: #047857;
}

.error-message {
    background: #fef2f2;
    border-color: var(--error-color);
}

.error-text {
    color: #991b1b;
    margin-bottom: 1rem;
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.modal {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    max-width: 500px;
    width: 100%;
    max-height: 80vh;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
    line-height: 1;
    padding: 0.25rem;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.modal-close:hover {
    background: var(--sidebar-bg);
    color: var(--text-primary);
}

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

/* History Detail Modal */
.history-detail-modal {
    max-width: 700px;
}

.history-modal-meta {
    display: flex;
    gap: 1rem;
    align-items: center;
    padding: 0.75rem 1rem;
    background: var(--sidebar-bg);
    border-radius: var(--radius-md);
    margin-bottom: 1rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.history-modal-meta .meta-item {
    display: flex;
    align-items: center;
    gap: 0.375rem;
}

.history-modal-meta .meta-badge {
    padding: 0.25rem 0.625rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    background: var(--primary-color);
    color: white;
}

.history-modal-meta .meta-badge.understood {
    background: var(--success-color);
}

.history-modal-content {
    max-height: 50vh;
    overflow-y: auto;
}

.profile-stat {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--sidebar-bg);
    border-radius: var(--radius-md);
    margin-bottom: 0.75rem;
}

.profile-stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.profile-stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.profile-section-title {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin: 1.5rem 0 0.75rem;
}

.understood-terms {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.understood-term-badge {
    padding: 0.375rem 0.75rem;
    background: #d1fae5;
    color: #065f46;
    border-radius: 9999px;
    font-size: 0.8rem;
    font-weight: 500;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(248, 250, 252, 0.95);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

/* ダークモード用ローディングオーバーレイ */
[data-theme="dark"] .loading-overlay {
    background: rgba(15, 23, 42, 0.95);
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

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

.loading-overlay p {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Responsive */
@media (max-width: 1024px) {
    .main-content {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        max-height: none;
        order: 2;
    }

    .content-area {
        order: 1;
    }

    .history-list {
        display: grid;
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
        gap: 0.75rem;
    }
}

@media (max-width: 640px) {
    .header {
        padding: 0.75rem 1rem;
    }

    .logo {
        font-size: 1.25rem;
    }

    .main-content {
        padding: 1rem;
    }

    .search-box {
        flex-direction: column;
    }

    .search-box input {
        font-size: 1rem;
    }

    .btn {
        width: 100%;
    }

    .card-header {
        flex-direction: column;
        gap: 0.75rem;
        text-align: center;
    }

    .card-actions {
        flex-direction: column;
    }

    .term-title {
        font-size: 1.25rem;
    }

    .welcome-message,
    .success-message,
    .error-message {
        padding: 2rem 1.5rem;
    }

    .history-list {
        grid-template-columns: 1fr;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--sidebar-bg);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

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

/* Hidden utility */
[hidden] {
    display: none !important;
}

/* Focus visible for accessibility */
:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .sidebar,
    .search-section,
    .card-actions,
    .header {
        display: none;
    }

    .explanation-card {
        box-shadow: none;
        border: none;
    }
}

/* ===========================
   Dashboard Section
   =========================== */

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.dashboard-section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
}

.dashboard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.dashboard-header h2 {
    font-size: 1.5rem;
    color: var(--text-primary);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

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

.stats-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    padding: 1.5rem;
    border-radius: var(--radius-md);
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

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

.stat-value {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    line-height: 1;
}

.stat-card:nth-child(2) .stat-value {
    color: var(--success-color);
}

.stat-card:nth-child(3) .stat-value {
    color: #8b5cf6;
}

.stat-card:nth-child(4) .stat-value {
    color: #f59e0b;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.chart-container {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: var(--radius-md);
    margin-bottom: 2rem;
    border: 1px solid var(--border-color);
}

.chart-container h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-size: 1.1rem;
}

.chart-wrapper {
    position: relative;
    height: 250px;
    width: 100%;
}

.chart-container canvas {
    max-width: 100%;
}

.recommendations-container {
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    padding: 1.5rem;
    border-radius: var(--radius-md);
    border: 1px solid #bfdbfe;
}

.recommendations-container h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-size: 1.1rem;
}

.recommendation-item {
    background: var(--card-bg);
    padding: 1rem 1.25rem;
    border-radius: var(--radius-md);
    margin-bottom: 0.75rem;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.recommendation-item:last-child {
    margin-bottom: 0;
}

.recommendation-item:hover {
    border-color: var(--primary-color);
    background: #f0f9ff;
    transform: translateX(4px);
}

.recommendation-term {
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
    font-size: 1rem;
}

.recommendation-reason {
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.4;
}

.recommendation-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.empty-recommendations {
    text-align: center;
    color: var(--text-muted);
    padding: 2rem;
}

/* Dashboard responsive */
@media (max-width: 768px) {
    .dashboard-section {
        padding: 1rem;
    }

    .dashboard-header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .stats-cards {
        grid-template-columns: repeat(2, 1fr);
    }

    .stat-value {
        font-size: 2rem;
    }
}

/* ===========================
   Glossary Section
   =========================== */

.glossary-section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
}

.glossary-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.glossary-header h2 {
    font-size: 1.5rem;
    color: var(--text-primary);
}

.glossary-content {
    padding: 0;
}

.glossary-progress-summary {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
    border: 1px solid #bbf7d0;
}

.progress-label {
    font-weight: 600;
    color: #166534;
}

.progress-numbers {
    font-size: 1.1rem;
    font-weight: 700;
    color: #15803d;
}

/* Dark mode glossary */
[data-theme="dark"] .glossary-section {
    background: var(--card-bg);
}

[data-theme="dark"] .glossary-progress-summary {
    background: linear-gradient(135deg, #14532d 0%, #166534 100%);
    border-color: #22c55e;
}

[data-theme="dark"] .progress-label {
    color: #bbf7d0;
}

[data-theme="dark"] .progress-numbers {
    color: #4ade80;
}

/* Glossary responsive */
@media (max-width: 768px) {
    .glossary-section {
        padding: 1rem;
    }

    .glossary-header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .glossary-progress-summary {
        flex-direction: column;
        text-align: center;
    }
}

/* ===========================
   Learning Center
   =========================== */

.learning-center-section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
}

.learning-center-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.learning-center-header h2 {
    font-size: 1.5rem;
    color: var(--text-primary);
}

/* タブナビゲーション */
.lc-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.lc-tab {
    padding: 0.75rem 1rem;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: var(--radius-md) var(--radius-md) 0 0;
    font-weight: 500;
    transition: var(--transition);
    white-space: nowrap;
}

.lc-tab:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

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

.lc-tab-content {
    display: none;
}

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

/* 連続学習バナー */
.streak-banner {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.5rem;
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
    border: 1px solid #fbbf24;
}

.streak-icon {
    font-size: 1.5rem;
}

.streak-text {
    color: #92400e;
    font-weight: 500;
}

.streak-text strong {
    font-size: 1.25rem;
    color: #b45309;
}

/* 学習パスグリッド */
.learning-paths-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.learning-path-card {
    background: var(--sidebar-bg);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    cursor: pointer;
    transition: var(--transition);
}

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

.learning-path-card.active {
    border-color: var(--success-color);
    background: linear-gradient(135deg, #f0fdf4 0%, #dcfce7 100%);
}

.path-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.path-icon {
    font-size: 1.5rem;
}

.path-name {
    font-weight: 600;
    color: var(--text-primary);
}

.path-description {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 0.75rem;
}

.path-steps {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.path-progress {
    margin-top: 0.75rem;
    padding-top: 0.75rem;
    border-top: 1px solid var(--border-color);
}

.path-progress-bar {
    height: 6px;
    background: var(--border-color);
    border-radius: 3px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.path-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
    border-radius: 3px;
    transition: width 0.3s ease;
}

.path-progress-text {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* 進行中パス */
.active-paths {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.active-path-item {
    background: var(--sidebar-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1rem;
}

.active-path-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
}

.active-path-name {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
}

.active-path-status {
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    background: var(--primary-light);
    color: var(--primary-color);
}

.active-path-status.completed {
    background: #dcfce7;
    color: #16a34a;
}

.next-term {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.next-term-link {
    color: var(--primary-color);
    cursor: pointer;
    text-decoration: underline;
}

.next-term-link:hover {
    color: var(--primary-dark);
}

/* バッジグリッド */
.badges-summary {
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: linear-gradient(135deg, #ede9fe 0%, #ddd6fe 100%);
    border-radius: var(--radius-md);
    text-align: center;
}

.badges-count {
    color: #5b21b6;
    font-weight: 500;
}

.badges-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.badge-card {
    background: var(--sidebar-bg);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    text-align: center;
    transition: var(--transition);
}

.badge-card.earned {
    border-color: #fbbf24;
    background: linear-gradient(135deg, #fefce8 0%, #fef9c3 100%);
}

.badge-card.locked {
    opacity: 0.6;
}

.badge-icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.badge-name {
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.badge-description {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.badge-earned-date {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
}

/* 復習セクション */
.review-due-section,
.review-upcoming-section {
    margin-bottom: 2rem;
}

.review-due-list,
.review-upcoming-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.review-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background: var(--sidebar-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
}

.review-item.due {
    border-color: #f97316;
    background: #fff7ed;
}

.review-term {
    font-weight: 500;
    color: var(--text-primary);
    cursor: pointer;
}

.review-term:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

.review-info {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.review-btn {
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
}

/* 練習統計 */
.practice-stats {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background: linear-gradient(135deg, #ecfeff 0%, #cffafe 100%);
    border-radius: var(--radius-md);
}

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

.practice-stats .stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: #0891b2;
}

.practice-stats .stat-label {
    font-size: 0.75rem;
    color: #0e7490;
}

/* 履歴リスト */
.practice-history-list,
.code-history-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    max-height: 300px;
    overflow-y: auto;
    margin-bottom: 2rem;
}

.history-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background: var(--sidebar-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
}

.history-item.correct {
    border-left: 3px solid #22c55e;
}

.history-item.incorrect {
    border-left: 3px solid #ef4444;
}

.history-term {
    font-weight: 500;
}

.history-result {
    font-size: 0.875rem;
}

.history-date {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.code-history-item {
    padding: 1rem;
    background: var(--sidebar-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
}

.code-history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.5rem;
}

.code-history-code {
    background: #1e293b;
    color: #e2e8f0;
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    font-family: monospace;
    font-size: 0.875rem;
    overflow-x: auto;
    white-space: pre-wrap;
    max-height: 150px;
    overflow-y: auto;
}

/* エクスポートセクション */
.export-section {
    text-align: center;
    padding: 2rem;
}

.export-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* ダークモード */
[data-theme="dark"] .streak-banner {
    background: linear-gradient(135deg, #78350f 0%, #92400e 100%);
    border-color: #b45309;
}

[data-theme="dark"] .streak-text {
    color: #fef3c7;
}

[data-theme="dark"] .streak-text strong {
    color: #fde68a;
}

[data-theme="dark"] .learning-path-card.active {
    background: linear-gradient(135deg, #14532d 0%, #166534 100%);
}

[data-theme="dark"] .badges-summary {
    background: linear-gradient(135deg, #4c1d95 0%, #5b21b6 100%);
}

[data-theme="dark"] .badges-count {
    color: #e9d5ff;
}

[data-theme="dark"] .badge-card.earned {
    background: linear-gradient(135deg, #78350f 0%, #92400e 100%);
}

[data-theme="dark"] .review-item.due {
    background: #7c2d12;
    border-color: #ea580c;
}

[data-theme="dark"] .practice-stats {
    background: linear-gradient(135deg, #164e63 0%, #155e75 100%);
}

[data-theme="dark"] .practice-stats .stat-value {
    color: #67e8f9;
}

[data-theme="dark"] .practice-stats .stat-label {
    color: #a5f3fc;
}

/* レスポンシブ */
@media (max-width: 768px) {
    .learning-center-section {
        padding: 1rem;
    }

    .learning-center-header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .lc-tabs {
        justify-content: center;
    }

    .lc-tab {
        padding: 0.5rem 0.75rem;
        font-size: 0.875rem;
    }

    .learning-paths-grid {
        grid-template-columns: 1fr;
    }

    .badges-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .practice-stats {
        flex-direction: column;
        gap: 1rem;
    }
}

/* Badge Notification */
.badge-notification {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10000;
    transform: translateX(120%);
    transition: transform 0.3s ease;
}

.badge-notification.show {
    transform: translateX(0);
}

.badge-notification-content {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.5rem;
    background: linear-gradient(135deg, #fef9c3 0%, #fde68a 100%);
    border: 2px solid #fbbf24;
    border-radius: var(--radius-lg);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.badge-notification-icon {
    font-size: 2rem;
}

.badge-notification-text {
    display: flex;
    flex-direction: column;
}

.badge-notification-text strong {
    color: #92400e;
    font-size: 0.875rem;
}

.badge-notification-text span {
    color: #78350f;
    font-weight: 600;
}

[data-theme="dark"] .badge-notification-content {
    background: linear-gradient(135deg, #78350f 0%, #92400e 100%);
}

[data-theme="dark"] .badge-notification-text strong {
    color: #fef3c7;
}

[data-theme="dark"] .badge-notification-text span {
    color: #fde68a;
}

/* Learning Path Notification */
.learning-path-notification {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10000;
    transform: translateX(120%);
    transition: transform 0.3s ease;
    max-width: 360px;
}

.learning-path-notification.show {
    transform: translateX(0);
}

.lp-notification-content {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    padding: 1.25rem;
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
    border: 2px solid #10b981;
    border-radius: var(--radius-lg);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
}

.lp-notification-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.lp-notification-icon {
    font-size: 1.75rem;
}

.lp-notification-text {
    flex: 1;
}

.lp-notification-text strong {
    display: block;
    color: #059669;
    font-size: 0.875rem;
    margin-bottom: 0.25rem;
}

.lp-notification-text span {
    color: #047857;
    font-weight: 500;
}

.lp-notification-progress {
    font-size: 0.75rem;
    color: #065f46;
    background: rgba(16, 185, 129, 0.2);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    text-align: center;
}

.lp-notification-action {
    display: flex;
    gap: 0.5rem;
}

.lp-next-term-btn {
    flex: 1;
    padding: 0.625rem 1rem;
    background: #10b981;
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.875rem;
}

.lp-next-term-btn:hover {
    background: #059669;
    transform: translateY(-1px);
}

.lp-notification-close {
    background: transparent;
    border: none;
    font-size: 1.25rem;
    color: #065f46;
    cursor: pointer;
    padding: 0.25rem;
    line-height: 1;
    opacity: 0.7;
    transition: opacity 0.2s;
}

.lp-notification-close:hover {
    opacity: 1;
}

/* Completed notification style */
.learning-path-notification.completed .lp-notification-content {
    background: linear-gradient(135deg, #fef9c3 0%, #fde68a 100%);
    border-color: #f59e0b;
}

.learning-path-notification.completed .lp-notification-text strong {
    color: #b45309;
}

.learning-path-notification.completed .lp-notification-text span {
    color: #92400e;
}

.learning-path-notification.completed .lp-notification-progress {
    background: rgba(245, 158, 11, 0.2);
    color: #92400e;
}

/* Dark mode */
[data-theme="dark"] .lp-notification-content {
    background: linear-gradient(135deg, #064e3b 0%, #065f46 100%);
}

[data-theme="dark"] .lp-notification-text strong {
    color: #6ee7b7;
}

[data-theme="dark"] .lp-notification-text span {
    color: #a7f3d0;
}

[data-theme="dark"] .lp-notification-progress {
    background: rgba(16, 185, 129, 0.3);
    color: #a7f3d0;
}

[data-theme="dark"] .lp-notification-close {
    color: #a7f3d0;
}

[data-theme="dark"] .learning-path-notification.completed .lp-notification-content {
    background: linear-gradient(135deg, #78350f 0%, #92400e 100%);
}

[data-theme="dark"] .learning-path-notification.completed .lp-notification-text strong {
    color: #fde68a;
}

[data-theme="dark"] .learning-path-notification.completed .lp-notification-text span {
    color: #fef3c7;
}

/* Learning Path Steps List (improved UI) */
.path-steps-list {
    margin-top: 0.75rem;
    padding-top: 0.75rem;
    border-top: 1px solid var(--border-color);
}

.path-step-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.375rem 0;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.path-step-item.completed {
    color: var(--success-color);
}

.path-step-item.current {
    color: var(--primary-color);
    font-weight: 600;
}

.path-step-item.pending {
    color: var(--text-muted);
}

.step-indicator {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    flex-shrink: 0;
}

.path-step-item.completed .step-indicator {
    background: var(--success-color);
    color: white;
}

.path-step-item.current .step-indicator {
    background: var(--primary-color);
    color: white;
    animation: pulse 2s infinite;
}

.path-step-item.pending .step-indicator {
    background: var(--border-color);
    color: var(--text-muted);
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.step-name {
    flex: 1;
    cursor: pointer;
    transition: color 0.2s;
}

.step-name:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

.path-step-item.completed .step-name:hover {
    color: var(--success-color);
}

.step-action-hint {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-style: italic;
}

/* ===========================
   Dark Mode Toggle
   =========================== */

.theme-toggle {
    background: var(--sidebar-bg);
    border: none;
    border-radius: var(--radius-md);
    padding: 0.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    transition: var(--transition);
    font-size: 1.2rem;
}

.theme-toggle:hover {
    background: var(--hover-bg);
    transform: rotate(15deg);
}

.theme-toggle .icon-sun,
.theme-toggle .icon-moon {
    transition: var(--transition);
}

[data-theme="dark"] .theme-toggle .icon-sun {
    display: none;
}

[data-theme="light"] .theme-toggle .icon-moon,
:root:not([data-theme]) .theme-toggle .icon-moon {
    display: none;
}

/* ===========================
   Progress Bar
   =========================== */

.progress-container {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
}

.progress-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), #8b5cf6, var(--success-color));
}

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

.progress-title {
    font-weight: 700;
    color: var(--text-primary);
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.progress-stats {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 600;
    background: var(--sidebar-bg);
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
}

.progress-bar-wrapper {
    background: var(--sidebar-bg);
    border-radius: 12px;
    height: 20px;
    overflow: hidden;
    position: relative;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1);
}

.progress-bar-fill {
    height: 100%;
    border-radius: 12px;
    background: linear-gradient(90deg,
        #3b82f6 0%,
        #8b5cf6 35%,
        #a855f7 65%,
        #10b981 100%
    );
    transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    box-shadow: 0 0 10px rgba(139, 92, 246, 0.4), 0 0 20px rgba(59, 130, 246, 0.2);
}

.progress-bar-fill::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 50%;
    background: linear-gradient(
        to bottom,
        rgba(255, 255, 255, 0.35) 0%,
        rgba(255, 255, 255, 0.1) 100%
    );
    border-radius: 12px 12px 0 0;
}

.progress-bar-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        90deg,
        transparent 0%,
        rgba(255, 255, 255, 0.4) 50%,
        transparent 100%
    );
    background-size: 200% 100%;
    animation: shimmer 2s infinite;
}

@keyframes progressPulse {
    0%, 100% { box-shadow: 0 0 10px rgba(139, 92, 246, 0.4), 0 0 20px rgba(59, 130, 246, 0.2); }
    50% { box-shadow: 0 0 15px rgba(139, 92, 246, 0.6), 0 0 30px rgba(59, 130, 246, 0.4); }
}

.progress-bar-fill.animating {
    animation: progressPulse 1.5s ease-in-out infinite;
}

.progress-milestones {
    display: flex;
    justify-content: space-between;
    margin-top: 1rem;
    font-size: 0.75rem;
    color: var(--text-muted);
    position: relative;
}

.milestone {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.375rem;
    padding: 0.5rem;
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
    min-width: 60px;
    position: relative;
}

.milestone::before {
    content: '';
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    width: 2px;
    height: 8px;
    background: var(--border-color);
    margin-bottom: 4px;
}

.milestone.achieved {
    color: var(--success-color);
    background: var(--success-light);
}

.milestone.achieved::before {
    background: var(--success-color);
}

.milestone.current {
    color: var(--primary-color);
    background: var(--primary-light);
    transform: scale(1.05);
    box-shadow: var(--shadow-sm);
}

.milestone.current::before {
    background: var(--primary-color);
}

.milestone-icon {
    font-size: 1.25rem;
    transition: transform 0.3s ease;
}

.milestone.achieved .milestone-icon,
.milestone.current .milestone-icon {
    animation: bounce 0.5s ease;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-4px); }
}

.milestone span:last-child {
    font-weight: 600;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

/* Keyword Index Section */
.keyword-index-section {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.keyword-index-title {
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--text-primary);
    margin: 0 0 1rem 0;
}

.keyword-index-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.keyword-index-subtitle {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.keyword-index-stats {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.9rem;
    background: var(--sidebar-bg);
    padding: 0.4rem 0.875rem;
    border-radius: 9999px;
}

.learned-count {
    font-weight: 700;
    color: var(--success-color);
}

.total-count {
    font-weight: 600;
    color: var(--text-secondary);
}

.stats-separator {
    color: var(--text-muted);
}

.stats-label {
    color: var(--text-muted);
    font-size: 0.8rem;
    margin-left: 0.25rem;
}

.keyword-index-toc {
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-height: 500px;
    overflow-y: auto;
    padding-right: 8px;
}

/* Category Item */
.category-item {
    background-color: #f1f5f9 !important;
    border: 1px solid #e2e8f0 !important;
    border-radius: 8px !important;
    overflow: visible !important;
}

.category-item:hover {
    border-color: var(--primary-color);
}

.category-header {
    display: flex !important;
    justify-content: space-between !important;
    align-items: center !important;
    padding: 12px 16px !important;
    cursor: pointer !important;
    user-select: none !important;
    min-height: 52px !important;
    background-color: transparent !important;
}

.category-header:hover {
    background-color: rgba(59, 130, 246, 0.1) !important;
}

.category-title {
    display: flex !important;
    align-items: center !important;
    gap: 8px !important;
    font-weight: 600 !important;
    font-size: 15px !important;
    color: #1e293b !important;
    line-height: 1.4 !important;
}

.category-icon {
    font-size: 1.2rem;
    flex-shrink: 0;
}

.category-name {
    color: inherit;
}

.category-meta {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-shrink: 0;
}

.category-progress {
    font-size: 0.8rem;
    font-weight: 600;
    color: #64748b;
    background: white;
    padding: 0.25rem 0.625rem;
    border-radius: 9999px;
    border: 1px solid #e2e8f0;
}

.category-progress.complete {
    background: #d1fae5;
    border-color: #10b981;
    color: #059669;
}

.category-toggle {
    font-size: 0.75rem;
    color: #64748b;
    transition: transform 0.2s ease;
}

.category-item.expanded .category-toggle {
    transform: rotate(180deg);
}

/* Category Keywords */
.category-keywords {
    display: none;
    padding: 1rem;
    border-top: 1px solid var(--border-color);
    background: white;
}

.category-item.expanded .category-keywords {
    display: block;
}

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

.keyword-btn {
    display: inline-flex;
    align-items: center;
    padding: 0.4rem 0.75rem;
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 9999px;
    font-size: 0.8rem;
    font-weight: 500;
    color: #475569;
    cursor: pointer;
    transition: all 0.2s ease;
}

.keyword-btn:hover {
    background: #dbeafe;
    border-color: #3b82f6;
    color: #2563eb;
    transform: translateY(-1px);
}

.keyword-btn.learned {
    background: #d1fae5;
    border-color: #10b981;
    color: #059669;
}

.keyword-btn.learned::before {
    content: '✓ ';
}

/* Dark mode - Keyword Index */
[data-theme="dark"] .keyword-index-section {
    background: #1e293b;
    border-color: #334155;
}

[data-theme="dark"] .keyword-index-title {
    color: #f1f5f9;
}

[data-theme="dark"] .keyword-index-header {
    border-bottom-color: #334155;
}

[data-theme="dark"] .keyword-index-subtitle {
    color: #94a3b8;
}

[data-theme="dark"] .keyword-index-stats {
    background: #334155;
}

[data-theme="dark"] .learned-count {
    color: #34d399;
}

[data-theme="dark"] .total-count {
    color: #cbd5e1;
}

[data-theme="dark"] .category-item {
    background-color: #334155 !important;
    border-color: #475569 !important;
}

[data-theme="dark"] .category-item:hover {
    border-color: #60a5fa;
}

[data-theme="dark"] .category-header:hover {
    background-color: rgba(96, 165, 250, 0.15) !important;
}

[data-theme="dark"] .category-title {
    color: #f1f5f9 !important;
}

[data-theme="dark"] .category-title span,
[data-theme="dark"] .category-name {
    color: #f1f5f9 !important;
}

[data-theme="dark"] .category-progress {
    background: #1e293b;
    border-color: #475569;
    color: #94a3b8;
}

[data-theme="dark"] .category-progress.complete {
    background: rgba(52, 211, 153, 0.2);
    border-color: #34d399;
    color: #34d399;
}

[data-theme="dark"] .category-toggle {
    color: #94a3b8;
}

[data-theme="dark"] .category-keywords {
    background: #1e293b;
    border-top-color: #475569;
}

[data-theme="dark"] .keyword-btn {
    background: #1e293b;
    border-color: #475569;
    color: #e2e8f0;
}

[data-theme="dark"] .keyword-btn:hover {
    background: rgba(96, 165, 250, 0.2);
    border-color: #60a5fa;
    color: #60a5fa;
}

[data-theme="dark"] .keyword-btn.learned {
    background: rgba(52, 211, 153, 0.15);
    border-color: #34d399;
    color: #34d399;
}

/* ===========================
   Mobile Menu Button
   =========================== */

.mobile-menu-btn {
    display: none;
    background: var(--sidebar-bg);
    border: none;
    border-radius: var(--radius-md);
    padding: 0.5rem;
    cursor: pointer;
    font-size: 1.5rem;
    line-height: 1;
    transition: var(--transition);
}

.mobile-menu-btn:hover {
    background: var(--hover-bg);
}

/* ===========================
   Enhanced Mobile Styles
   =========================== */

@media (max-width: 768px) {
    /* Header mobile */
    .header {
        padding: 0.5rem 0.75rem;
        flex-wrap: nowrap;
        gap: 0.4rem;
    }

    .header-left {
        flex-shrink: 1;
        min-width: 0;
        gap: 0.4rem;
    }

    .logo {
        font-size: 0.95rem;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .header-actions {
        display: flex;
        align-items: center;
        gap: 0.4rem;
        flex-wrap: nowrap;
        flex-shrink: 0;
    }

    .header-actions #open-dashboard-btn {
        padding: 0.4rem 0.5rem;
        font-size: 0.7rem;
    }

    .header-actions #open-dashboard-btn .btn-label,
    .header-actions #open-glossary-btn .btn-label,
    .header-actions #open-learning-center-btn .btn-label {
        display: none;
    }

    .header-actions #open-glossary-btn,
    .header-actions #open-learning-center-btn {
        padding: 0.4rem;
    }

    .header-actions .theme-toggle {
        width: 32px;
        height: 32px;
        flex-shrink: 0;
        font-size: 1rem;
    }

    .header-actions .profile-summary {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
        width: 36px;
        height: 36px;
        flex-shrink: 0;
    }

    /* Main content mobile */
    .main-content {
        flex-direction: column;
        padding: 1rem;
        gap: 1rem;
    }

    /* Sidebar mobile - collapsible */
    .sidebar {
        width: 100%;
        max-height: none;
        position: fixed;
        top: 0;
        left: -100%;
        height: 100vh;
        z-index: 200;
        border-radius: 0;
        transition: left 0.3s ease;
        overflow-y: auto;
    }

    .sidebar.open {
        left: 0;
    }

    .sidebar-overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.5);
        z-index: 199;
        opacity: 0;
        transition: opacity 0.3s ease;
    }

    .sidebar-overlay.visible {
        display: block;
        opacity: 1;
    }

    .sidebar-close-btn {
        display: block;
        position: absolute;
        top: 1rem;
        right: 1rem;
        background: none;
        border: none;
        font-size: 1.5rem;
        cursor: pointer;
        color: var(--text-secondary);
    }

    /* Content area mobile */
    .content-area {
        width: 100%;
    }

    .search-box {
        flex-direction: column;
    }

    .search-box input {
        width: 100%;
    }

    .search-box .btn {
        width: 100%;
    }

    /* Cards mobile */
    .explanation-card,
    .practice-card,
    .additional-explanation-card {
        padding: 1rem;
        animation: fadeInUp 0.3s ease;
    }

    .card-header {
        flex-direction: column;
        gap: 0.75rem;
        align-items: flex-start;
    }

    .card-actions {
        flex-direction: column;
        gap: 0.5rem;
    }

    .card-actions .btn {
        width: 100%;
        justify-content: center;
    }

    /* Practice mobile */
    .practice-actions {
        flex-direction: column;
        gap: 0.5rem;
    }

    .practice-actions .btn {
        width: 100%;
    }

    .monaco-editor-container {
        height: 200px !important;
    }

    /* Modal mobile */
    .modal {
        width: 95%;
        max-width: none;
        margin: 1rem;
        max-height: 90vh;
    }

    /* Welcome message mobile */
    .welcome-message {
        padding: 2rem 1rem;
    }

    .example-terms {
        flex-wrap: wrap;
        justify-content: center;
    }

    /* Related keywords mobile */
    .related-keywords-list {
        flex-direction: column;
    }

    .related-keyword-btn {
        width: 100%;
        text-align: center;
    }

    /* Progress bar mobile */
    .progress-container {
        padding: 1rem;
    }

    .progress-header {
        flex-direction: row;
        align-items: center;
        gap: 0.5rem;
    }

    .progress-bar-wrapper {
        height: 16px;
    }

    .progress-milestones {
        margin-top: 0.75rem;
    }

    .milestone {
        min-width: 50px;
        padding: 0.375rem;
    }

    .milestone::before {
        height: 6px;
    }

    .milestone-icon {
        font-size: 1rem;
    }

    .milestone span:last-child {
        font-size: 0.6rem;
    }

    /* Keyword index mobile */
    .keyword-index-section {
        padding: 1rem;
        margin-bottom: 1.5rem;
    }

    .keyword-index-title {
        font-size: 1rem;
    }

    .keyword-index-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .keyword-index-toc {
        max-height: 350px;
    }

    .category-header {
        padding: 0.6rem 0.75rem;
    }

    .category-title {
        font-size: 0.85rem;
    }

    .keyword-btn {
        font-size: 0.7rem;
        padding: 0.3rem 0.6rem;
    }

    /* Progress bar in dashboard mobile */
    .progress-container {
        padding: 1rem;
        margin-bottom: 1.5rem;
    }
}

/* Small mobile */
@media (max-width: 480px) {
    /* Header very small */
    .header {
        padding: 0.4rem 0.5rem;
        gap: 0.3rem;
    }

    .header-left {
        gap: 0.3rem;
    }

    .logo {
        font-size: 0.85rem;
    }

    /* Hide dashboard, glossary, and learning center button text, show only icon */
    .header-actions #open-dashboard-btn .btn-label,
    .header-actions #open-glossary-btn .btn-label,
    .header-actions #open-learning-center-btn .btn-label {
        display: none;
    }

    .header-actions #open-dashboard-btn,
    .header-actions #open-glossary-btn,
    .header-actions #open-learning-center-btn {
        padding: 0.4rem;
    }

    .mobile-menu-btn {
        width: 32px;
        height: 32px;
        font-size: 1.2rem;
    }

    .stats-cards {
        grid-template-columns: 1fr;
    }

    .stat-card {
        padding: 1rem;
    }

    .stat-value {
        font-size: 1.75rem;
    }

    .level-indicator {
        flex-wrap: wrap;
        gap: 0.25rem;
    }

    .level-badge {
        font-size: 0.7rem;
        padding: 0.2rem 0.5rem;
    }

    .history-item {
        padding: 0.625rem;
    }

    .history-term {
        font-size: 0.85rem;
    }

    .history-meta {
        flex-wrap: wrap;
        gap: 0.25rem 0.5rem;
    }

    .history-level {
        font-size: 0.6rem;
        padding: 0.1rem 0.4rem;
    }
}

/* ===========================
   Dark Mode Specific Overrides
   =========================== */

[data-theme="dark"] .recommendations-container {
    background: linear-gradient(135deg, #1e3a5f 0%, #1e293b 100%);
    border-color: #334155;
}

[data-theme="dark"] .recommendation-item {
    background: var(--card-bg);
}

[data-theme="dark"] .recommendation-item:hover {
    background: var(--hover-bg);
}

[data-theme="dark"] .search-box input {
    background: var(--card-bg);
    color: var(--text-primary);
}

[data-theme="dark"] .search-box input::placeholder {
    color: var(--text-muted);
}

[data-theme="dark"] .modal {
    background: var(--card-bg);
}

[data-theme="dark"] .history-item:hover {
    background: var(--hover-bg);
}

[data-theme="dark"] code {
    background: #0f172a;
}

[data-theme="dark"] pre {
    background: #0f172a !important;
}

[data-theme="dark"] .example-btn {
    background: var(--sidebar-bg);
    border-color: var(--border-color);
    color: var(--text-primary);
}

[data-theme="dark"] .example-btn:hover {
    background: var(--hover-bg);
    border-color: var(--primary-color);
}

/* Dark mode - Stats cards */
[data-theme="dark"] .stat-card {
    background: var(--card-bg);
    border-color: var(--border-color);
}

[data-theme="dark"] .stat-label {
    color: var(--text-secondary);
}

/* Dark mode - Related keywords */
[data-theme="dark"] .related-keywords {
    background: var(--card-bg);
    border-color: var(--border-color);
}

[data-theme="dark"] .related-keywords-header {
    color: var(--text-primary);
}

[data-theme="dark"] .related-keyword-btn {
    background: var(--sidebar-bg);
    border-color: var(--border-color);
    color: var(--text-primary);
}

[data-theme="dark"] .related-keyword-btn:hover {
    background: var(--hover-bg);
    border-color: var(--primary-color);
}

/* Dark mode - Dashboard */
[data-theme="dark"] .dashboard-section {
    background: var(--bg-color);
}

[data-theme="dark"] .chart-container {
    background: var(--card-bg);
    border-color: var(--border-color);
}

/* Dark mode - Progress bar */
[data-theme="dark"] .progress-container {
    background: var(--card-bg);
    border-color: var(--border-color);
}

[data-theme="dark"] .progress-container::before {
    background: linear-gradient(90deg, #60a5fa, #a78bfa, #34d399);
}

[data-theme="dark"] .progress-bar-wrapper {
    background: var(--border-color);
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.3);
}

[data-theme="dark"] .progress-bar-fill {
    box-shadow: 0 0 15px rgba(139, 92, 246, 0.5), 0 0 25px rgba(96, 165, 250, 0.3);
}

[data-theme="dark"] .progress-stats {
    background: var(--border-color);
    color: var(--text-primary);
}

[data-theme="dark"] .milestone::before {
    background: var(--border-color);
}

[data-theme="dark"] .milestone.achieved {
    background: rgba(52, 211, 153, 0.2);
}

[data-theme="dark"] .milestone.current {
    background: rgba(96, 165, 250, 0.2);
}

/* Dark mode - Buttons */
[data-theme="dark"] .btn-outline {
    background: var(--card-bg);
    border-color: var(--border-color);
    color: var(--text-primary);
}

[data-theme="dark"] .btn-outline:hover {
    background: var(--hover-bg);
    border-color: var(--primary-color);
}

[data-theme="dark"] .btn-secondary {
    background: var(--card-bg);
    border-color: var(--border-color);
    color: var(--text-primary);
}

[data-theme="dark"] .btn-secondary:hover:not(:disabled) {
    background: var(--hover-bg);
}

/* Smooth transition for theme change (only after page load) */
body.theme-ready,
body.theme-ready .header,
body.theme-ready .sidebar,
body.theme-ready .card-bg,
body.theme-ready .explanation-card,
body.theme-ready .practice-card,
body.theme-ready .modal,
body.theme-ready input,
body.theme-ready button {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

/* ===========================
   Touch-friendly improvements
   =========================== */

@media (hover: none) and (pointer: coarse) {
    .btn {
        min-height: 44px;
        min-width: 44px;
    }

    .history-item {
        min-height: 60px;
    }

    .example-btn {
        min-height: 44px;
        padding: 0.75rem 1.25rem;
    }

    .theme-toggle,
    .mobile-menu-btn {
        min-width: 44px;
        min-height: 44px;
    }
}

/* ===========================
   Login Screen
   =========================== */

.login-screen {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-color);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.login-container {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: 2.5rem;
    max-width: 400px;
    width: 100%;
    margin: 1rem;
    animation: fadeInUp 0.4s ease;
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-logo {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.login-header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.login-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.login-input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.login-input-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
}

.login-input-group input {
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    background: var(--bg-color);
    color: var(--text-primary);
    transition: var(--transition);
}

.login-input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.login-hint {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin: 0;
}

.btn-login {
    padding: 0.875rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    width: 100%;
}

.login-note {
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin: 0;
}

.login-error {
    margin-top: 1rem;
    padding: 0.75rem 1rem;
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--error-color);
    border-radius: var(--radius-md);
    color: var(--error-color);
    font-size: 0.875rem;
    text-align: center;
}

/* Logout button */
.btn-logout {
    display: flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.5rem 0.75rem;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.8rem;
    cursor: pointer;
    transition: var(--transition);
}

.btn-logout:hover {
    background: var(--error-color);
    border-color: var(--error-color);
    color: white;
}

/* Username display */
.username-display {
    font-weight: 600;
    color: var(--primary-color);
    margin-left: 0.5rem;
    font-size: 0.85rem;
}

/* Mobile responsive login */
@media (max-width: 768px) {
    .login-container {
        padding: 1.5rem;
        margin: 0.5rem;
    }

    .login-logo {
        font-size: 3rem;
    }

    .login-header h1 {
        font-size: 1.5rem;
    }

    .btn-logout .logout-text {
        display: none;
    }
}

/* ===========================
   Toast Notifications
   =========================== */

.toast-notification {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--card-bg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: 1rem 1.5rem;
    z-index: 3000;
    opacity: 0;
    transition: transform 0.3s ease, opacity 0.3s ease;
    border: 1px solid var(--border-color);
}

.toast-notification.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast-content {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

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

.toast-message {
    font-size: 0.95rem;
    color: var(--text-primary);
}

.toast-success .toast-icon {
    color: var(--success-color);
}

.toast-error .toast-icon {
    color: var(--error-color);
}

.toast-info .toast-icon {
    color: var(--primary-color);
}