:root {
    --color-brand: #4F46E5;
    --color-brand-hover: #4338CA;
    --color-bg-body: #0F172A;
    --color-bg-panel: #1E293B;
    --color-bg-card: #0B0F19;
    --color-bg-hover: #334155;
    --color-bg-active: #1E1B4B;
    --color-border-main: #334155;
    --color-border-light: #475569;
    --color-border-focus: #6366F1;
    --color-text-primary: #F8FAFC;
    --color-text-secondary: #CBD5E1;
    --color-text-tertiary: #94A3B8;
    --color-success: #10B981;
    --color-success-bg: #064E3B;
    --color-warning: #F59E0B;
    --color-warning-bg: #451A03;
    --color-danger: #EF4444;
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
}

[data-theme="light"] {
    --color-bg-body: #F1F5F9;
    --color-bg-panel: #FFFFFF;
    --color-bg-card: #F8FAFC;
    --color-bg-hover: #E2E8F0;
    --color-bg-active: #EEF2FF;
    --color-border-main: #E2E8F0;
    --color-border-light: #CBD5E1;
    --color-text-primary: #0F172A;
    --color-text-secondary: #334155;
    --color-text-tertiary: #64748B;
    --color-success-bg: #DCFCE7;
    --color-warning-bg: #FEF3C7;
}

[data-theme="light"] .editor-header,
[data-theme="light"] .editor-footer {
    background: #F8FAFC;
    color: var(--color-text-secondary);
}

[data-theme="light"] .code-input {
    background: #F1F5F9;
    color: var(--color-text-primary) !important;
}

[data-theme="light"] .code-input:focus {
    color: var(--color-text-primary);
    background: #FFFFFF;
}

[data-theme="light"] code {
    background: rgba(0, 0, 0, 0.05) !important;
    color: var(--color-brand) !important;
}

[data-theme="light"] .tmpl-title {
    color: var(--color-text-primary);
}

[data-theme="light"] .badge.pro {
    background: #FEF3C7 !important;
    color: #92400E !important;
}

[data-theme="light"] .badge.free {
    background: #DCFCE7 !important;
    color: #166534 !important;
}

[data-theme="light"] .tab:not(.active) {
    color: var(--color-text-tertiary);
}

[data-theme="light"] .nav-item:not(.active) {
    color: var(--color-text-secondary);
}

[data-theme="light"] .ai-header {
    background: #EEF2FF;
    color: var(--color-brand);
}

[data-theme="light"] .bubble b {
    color: var(--color-brand);
}

[data-theme="light"] .flow-section {
    background: rgba(0, 0, 0, 0.03);
}

[data-theme="light"] .flow-note {
    background: rgba(0, 0, 0, 0.03);
    color: var(--color-text-secondary);
}

[data-theme="light"] .ram-table th {
    background: #F1F5F9;
}

[data-theme="light"] .ram-table td.active {
    background: #F0FDF4;
}

[data-theme="light"] svg rect {
    fill: #FFFFFF;
}

[data-theme="light"] svg text {
    fill: var(--color-text-primary);
}

[data-theme="light"] svg text[fill="#94A3B8"] {
    fill: var(--color-text-tertiary);
}

[data-theme="light"] .sb-header {
    border-bottom-color: var(--color-border-main);
}

[data-theme="light"] .lang-selector {
    background: var(--color-bg-card) !important;
    border-color: var(--color-border-main) !important;
}

.theme-toggle {
    cursor: pointer;
    font-size: 20px;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background 0.2s;
    user-select: none;
    border: 1px solid var(--color-border-main);
    background: var(--color-bg-card);
}

.theme-toggle:hover {
    background: var(--color-bg-hover);
}

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

body {
    font-family: var(--font-sans);
    background: var(--color-bg-body);
    color: var(--color-text-primary);
    padding: 20px;
    display: flex;
    justify-content: center;
    min-height: 100vh;
    align-items: flex-start;
}

.mt-16 {
    margin-top: 16px;
}

.mt-24 {
    margin-top: 24px;
}

.mono {
    font-family: var(--font-mono);
}

.app {
    display: flex;
    width: 1280px;
    max-width: 100%;
    height: 85vh;
    min-height: 720px;
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    background: var(--color-bg-panel);
}

.sb {
    width: 240px;
    min-width: 240px;
    background: var(--color-bg-body);
    border-right: 1px solid var(--color-border-main);
    display: flex;
    flex-direction: column;
}

.mc {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    background: var(--color-bg-panel);
    overflow-x: hidden;
}

/* Sidebar */
.sb-header {
    padding: 16px;
    border-bottom: 1px solid var(--color-border-main);
}

.sb-logo-area {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
}

.sb-logo-icon {
    width: 28px;
    height: 28px;
    border-radius: 6px;
    background: var(--color-brand);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 700;
    color: #fff;
    box-shadow: 0 4px 6px rgba(79, 70, 229, 0.3);
}

.sb-logo-text {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.sb-logo-sub {
    font-size: 9px;
    color: var(--color-text-tertiary);
    margin-top: 2px;
}

.lang-selector {
    padding: 8px 10px;
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-md);
    background: var(--color-bg-card);
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    transition: all 0.2s;
}

.lang-selector:hover {
    border-color: var(--color-border-focus);
}

.lang-dropdown-wrapper {
    position: relative;
    width: 100%;
}

.lang-modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(8px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.lang-modal-overlay.open {
    display: flex;
}

.lang-modal {
    background: var(--color-bg-panel);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-lg);
    width: 90%;
    max-width: 600px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.lang-modal-header {
    padding: 20px;
    border-bottom: 1px solid var(--color-border-main);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.lang-modal-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--color-text-primary);
}

.lang-modal-close {
    cursor: pointer;
    font-size: 20px;
    color: var(--color-text-tertiary);
    transition: color 0.2s;
}

.lang-modal-close:hover {
    color: var(--color-brand);
}

.lang-modal-body {
    padding: 24px;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 12px;
    max-height: 400px;
    overflow-y: auto;
}

.lang-item {
    padding: 8px 12px;
    font-size: 11px;
    color: var(--color-text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: background 0.2s;
}

.lang-item:hover {
    background: var(--color-bg-hover);
    color: var(--color-text-primary);
}

.lang-item.selected {
    background: rgba(79, 70, 229, 0.1);
    color: var(--color-brand);
}

.lang-item .check {
    margin-left: auto;
    width: 14px;
    height: 14px;
    border: 1px solid var(--color-border-light);
    border-radius: 2px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    transition: all 0.2s;
}

.lang-item.selected .check {
    background: var(--color-brand);
    border-color: var(--color-brand);
    color: white;
}

.lang-item.selected .check::after {
    content: '✓';
}

.lang-dots {
    display: flex;
    gap: 3px;
}

.dot {
    width: 8px;
    height: 8px;
    border-radius: 2px;
}

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

.sb-content::-webkit-scrollbar {
    width: 4px;
}

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

.acc-header {
    padding: 10px 16px;
    font-size: 13px;
    color: var(--color-text-secondary);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.2s;
    background: var(--color-bg-panel);
    position: sticky;
    top: 0;
    z-index: 10;
    border-bottom: 1px solid var(--color-border-main);
    border-top: 1px solid var(--color-border-main);
    margin-top: -1px;
    font-weight: 600;
}

.acc-header:hover {
    background: var(--color-bg-hover);
    color: var(--color-text-primary);
}

.acc-body {
    display: none;
    padding: 4px 0;
}

.acc-body.open {
    display: block;
}

.nav-item {
    padding: 8px 16px 8px 24px;
    font-size: 13px;
    color: var(--color-text-tertiary);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    border-left: 2px solid transparent;
    transition: all 0.2s;
}

.nav-item:hover {
    background: var(--color-bg-hover);
    color: var(--color-text-secondary);
}

.nav-item.active {
    background: var(--color-bg-active);
    color: var(--color-brand);
    border-left: 2px solid var(--color-brand);
    font-weight: 500;
}

.nav-num {
    font-family: var(--font-mono);
    font-size: 11px;
    opacity: 0.6;
    min-width: 18px;
}

.badge {
    font-size: 8px;
    padding: 2px 5px;
    border-radius: 3px;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.badge.free {
    background: rgba(16, 185, 129, 0.1);
    color: var(--color-success);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.badge.pro {
    background: rgba(245, 158, 11, 0.1);
    color: var(--color-warning);
    border: 1px solid rgba(245, 158, 11, 0.2);
}

.sb-footer {
    padding: 12px 16px;
    border-top: 1px solid var(--color-border-main);
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--color-bg-body);
}

.user-avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--color-bg-hover);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    color: var(--color-text-secondary);
}

/* Main Content */
.mc-header {
    padding: 16px 24px;
    border-bottom: 1px solid var(--color-border-main);
    background: var(--color-bg-body);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.breadcrumb {
    font-size: 11px;
    color: var(--color-text-tertiary);
    margin-bottom: 4px;
}

.mc-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--color-text-primary);
    display: flex;
    align-items: center;
    gap: 10px;
}

.progress-bar {
    width: 100px;
    height: 4px;
    background: var(--color-bg-hover);
    border-radius: 2px;
    overflow: hidden;
}

.progress-fill {
    width: 35%;
    height: 100%;
    background: var(--color-brand);
}

.tabs-container {
    background: var(--color-bg-body);
    border-bottom: 1px solid var(--color-border-main);
    width: 100%;
}

.tabs {
    display: flex;
    padding: 0 24px;
}

.tab {
    padding: 12px 16px;
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text-tertiary);
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 6px;
}

.tab:hover {
    color: var(--color-text-secondary);
}

.tab.active {
    color: var(--color-brand);
    border-bottom-color: var(--color-brand);
}

.panel {
    display: none;
    padding: 24px;
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    overflow-x: hidden;
}

.panel.active {
    display: block;
}

.panel::-webkit-scrollbar {
    width: 6px;
}

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

/* Mockup Specifics */
.guideline {
    font-size: 10px;
    color: var(--color-brand);
    border: 1px dashed var(--color-border-focus);
    background: rgba(79, 70, 229, 0.05);
    border-radius: var(--border-radius-sm);
    padding: 6px 10px;
    display: inline-block;
    margin-bottom: 20px;
}

.section-title {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--color-text-primary);
}

/* --- STAGE 1: Concept & Cards --- */
.lang-cards-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
    margin-top: 16px;
}

.lcard {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-lg);
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    transition: transform 0.2s;
}

.lcard:hover {
    transform: translateY(-2px);
    border-color: var(--color-border-light);
}

.lcard-header {
    display: flex;
    align-items: center;
    gap: 8px;
}

.lang-tag {
    font-size: 11px;
    padding: 3px 8px;
    border-radius: 4px;
    font-weight: 600;
}

.lang-tag.c1 {
    background: rgba(239, 68, 68, 0.15);
    color: #FCA5A5;
}

.lang-tag.c2 {
    background: rgba(59, 130, 246, 0.15);
    color: #93C5FD;
}

.lang-tag.c3 {
    background: rgba(139, 92, 246, 0.15);
    color: #C4B5FD;
}

.lang-tag.c4 {
    background: rgba(16, 185, 129, 0.15);
    color: #6EE7B7;
}

.lang-tag-sub {
    font-size: 10px;
    color: var(--color-text-tertiary);
}

.lcard-code {
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--color-text-secondary);
    background: rgba(255, 255, 255, 0.03);
    padding: 12px;
    border-radius: var(--border-radius-md);
    line-height: 1.6;
}

.c-comment {
    color: var(--color-text-tertiary);
    opacity: 0.7;
}

.lcard-desc {
    font-size: 11px;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

.story-grid-container {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-lg);
    padding: 20px;
}

.story-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
}

.story-item {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-md);
    padding: 16px;
    text-align: center;
}

.story-emoji {
    font-size: 28px;
    margin-bottom: 8px;
}

.story-title {
    font-size: 12px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: 4px;
}

.story-desc {
    font-size: 11px;
    color: var(--color-text-tertiary);
    line-height: 1.4;
}

/* --- STAGE 2: Typing interface --- */
.lang-toolbar {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.tb-btn {
    padding: 4px 10px;
    font-size: 11px;
    border: 1px solid var(--color-border-main);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
    color: var(--color-text-secondary);
}

.tb-btn:hover {
    background: var(--color-bg-hover);
}

.tb-btn.active {
    background: rgba(16, 185, 129, 0.1);
    border-color: var(--color-success);
    color: var(--color-success);
    font-weight: 500;
}

.tb-stats {
    margin-left: auto;
    font-size: 11px;
    color: var(--color-text-tertiary);
}

.typing-container {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
}

.typing-split {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    border-bottom: 1px solid var(--color-border-main);
}

.typing-box {
    padding: 16px;
    border-right: 1px solid var(--color-border-main);
}

.typing-box:last-child {
    border-right: none;
}

.typing-label {
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--color-text-tertiary);
    margin-bottom: 12px;
    font-weight: 600;
}

.typing-content {
    font-family: var(--font-mono);
    font-size: 15px;
    line-height: 2;
    color: var(--color-text-primary);
}

.typing-content.ghost {
    color: var(--color-text-tertiary);
    opacity: 0.6;
}

.correct {
    color: var(--color-success);
}

.untyped {
    color: var(--color-text-tertiary);
    opacity: 0.5;
}

.cursor {
    display: inline-block;
    width: 2px;
    height: 14px;
    background: var(--color-brand);
    vertical-align: middle;
    animation: blink 1s infinite;
}

@keyframes blink {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0;
    }
}

.typing-footer {
    padding: 10px 16px;
    background: rgba(255, 255, 255, 0.02);
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: 11px;
    color: var(--color-text-secondary);
}

.diagram-box {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
}

.diagram-header {
    padding: 12px 16px;
    background: rgba(255, 255, 255, 0.03);
    border-bottom: 1px solid var(--color-border-main);
    font-size: 13px;
    font-weight: 600;
    color: var(--color-text-primary);
}

.diagram-body {
    padding: 24px;
}

/* FLOW SECTION STYLES */
.flow-section {
    margin-top: 32px;
    padding: 24px;
    background: rgba(15, 23, 42, 0.4);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-lg);
}

.flow-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-brand);
    margin-bottom: 20px;
}

.flow-steps {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    margin-bottom: 30px;
}

.flow-step {
    flex: 1;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-md);
    padding: 16px;
    text-align: center;
    position: relative;
    transition: transform 0.3s;
}

.flow-step:hover {
    transform: translateY(-5px);
    border-color: var(--color-brand);
}

.flow-step-icon {
    font-size: 24px;
    margin-bottom: 8px;
}

.flow-step-label {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: 4px;
}

.flow-step-desc {
    font-size: 13px;
    color: var(--color-text-tertiary);
    line-height: 1.4;
}

.flow-arrow {
    color: var(--color-text-tertiary);
    font-size: 18px;
}

.ram-map-container {
    margin-top: 24px;
}

.ram-map-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text-secondary);
    margin-bottom: 12px;
}

.ram-table {
    width: 100%;
    border-collapse: collapse;
    font-family: var(--font-mono);
    font-size: 15px;
}

.ram-table th,
.ram-table td {
    border: 1px solid var(--color-border-main);
    padding: 12px;
    text-align: center;
}

.ram-table th {
    background: var(--color-bg-body);
    color: var(--color-text-tertiary);
    font-size: 11px;
    font-weight: normal;
}

.ram-table td {
    background: var(--color-bg-card);
    color: var(--color-text-secondary);
}

.ram-table td.active {
    color: var(--color-success);
    font-weight: 700;
    background: rgba(16, 185, 129, 0.05);
}

.flow-note {
    margin-top: 20px;
    font-size: 14px;
    color: var(--color-text-tertiary);
    text-align: center;
    padding: 12px;
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--border-radius-md);
}

/* COMPLEX SVG ANIMATIONS */
@keyframes flowLine {
    to {
        stroke-dashoffset: 0;
    }
}

.anim-path {
    stroke-dasharray: 1000;
    stroke-dashoffset: 1000;
    animation: flowLine 3s ease-out forwards;
}

@keyframes pulse-dot {
    0% {
        r: 2;
        opacity: 0.5;
    }

    50% {
        r: 4;
        opacity: 1;
    }

    100% {
        r: 2;
        opacity: 0.5;
    }
}

.pulse-node {
    animation: pulse-dot 2s infinite;
}

.glow-path {
    filter: drop-shadow(0 0 3px var(--color-brand));
}

/* --- STAGE 3: Templates --- */
.split-view {
    display: grid;
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
    gap: 20px;
    min-height: 480px;
}

.editor-container {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-lg);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.editor-header {
    padding: 10px 16px;
    background: #0F172A;
    border-bottom: 1px solid var(--color-border-main);
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--color-text-secondary);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.editor-body {
    padding: 16px;
    flex: 1;
    overflow-y: auto;
    font-family: var(--font-mono);
    font-size: 14px;
    line-height: 1.7;
}

.editor-footer {
    padding: 12px 16px;
    background: #0F172A;
    border-top: 1px solid var(--color-border-main);
    display: flex;
    gap: 10px;
    align-items: center;
}

.code-hint-block {
    margin-bottom: 20px;
    border-left: 2px solid transparent;
    padding-left: 12px;
    transition: all 0.3s;
}

.code-hint-block.active {
    border-left-color: var(--color-warning);
    background: linear-gradient(90deg, rgba(245, 158, 11, 0.05) 0%, transparent 100%);
    border-radius: 0 var(--border-radius-md) var(--border-radius-md) 0;
}

.korean-comment {
    color: var(--color-success);
    font-family: var(--font-sans);
    font-size: 13px;
    margin-bottom: 6px;
}

.code-line {
    color: var(--color-text-primary);
    display: flex;
    align-items: center;
}

.code-input {
    background: rgba(0, 0, 0, 0.3);
    border: 1px dashed var(--color-border-light);
    border-radius: 4px;
    padding: 4px 8px;
    color: var(--color-text-secondary);
    width: 100%;
    cursor: text;
    transition: all 0.2s;
    outline: none;
}

.code-input:focus {
    border-color: var(--color-brand);
    background: rgba(79, 70, 229, 0.1);
    border-style: solid;
    box-shadow: 0 0 0 2px rgba(79, 70, 229, 0.2);
    color: #fff;
}

.btn {
    padding: 8px 14px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--color-border-main);
    color: var(--color-text-secondary);
}

.btn-outline:hover {
    background: var(--color-bg-hover);
    color: var(--color-text-primary);
}

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

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

/* AI Tutor Area */
.tutor-container {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.ai-chat {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.ai-header {
    padding: 12px 16px;
    background: rgba(79, 70, 229, 0.1);
    border-bottom: 1px solid rgba(79, 70, 229, 0.2);
    display: flex;
    align-items: center;
    gap: 8px;
}

.ai-icon {
    width: 24px;
    height: 24px;
    border-radius: 6px;
    background: var(--color-brand);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
}

.ai-title {
    font-size: 14px;
    font-weight: 600;
    color: #fff;
}

.ai-body {
    padding: 16px;
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.msg {
    display: flex;
    flex-direction: column;
    max-width: 90%;
    gap: 4px;
}

.msg.ai {
    align-self: flex-start;
}

.msg.user {
    align-self: flex-end;
}

.bubble {
    padding: 10px 14px;
    border-radius: 12px;
    font-size: 14px;
    line-height: 1.5;
}

.msg.ai .bubble {
    background: var(--color-bg-hover);
    color: var(--color-text-primary);
    border-bottom-left-radius: 4px;
    border: 1px solid var(--color-border-main);
}

.msg.user .bubble {
    background: var(--color-brand);
    color: #fff;
    border-bottom-right-radius: 4px;
}

.hint-pyramid {
    display: flex;
    gap: 6px;
    margin-top: 10px;
}

.hint-dot {
    width: 30px;
    height: 4px;
    border-radius: 2px;
    background: var(--color-border-main);
}

.hint-dot.active {
    background: var(--color-success);
}

.hint-dot.warn {
    background: var(--color-warning);
}

.hint-dot.danger {
    background: var(--color-danger);
}

.preview-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-lg);
    padding: 16px;
}

.preview-header {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--color-text-tertiary);
    margin-bottom: 12px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 6px;
}

.tmpl-grid {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
    overflow-x: auto;
    padding-bottom: 8px;
}

.tmpl-grid::-webkit-scrollbar {
    height: 4px;
}

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

.tmpl-item {
    min-width: 140px;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border-main);
    border-radius: var(--border-radius-md);
    padding: 12px;
    cursor: pointer;
    transition: all 0.2s;
}

.tmpl-item:hover {
    border-color: var(--color-border-focus);
    transform: translateY(-2px);
}

.tmpl-item.active {
    border-color: var(--color-brand);
    background: rgba(79, 70, 229, 0.05);
}

.tmpl-icon {
    font-size: 20px;
    margin-bottom: 8px;
}

.tmpl-title {
    font-size: 13px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: 4px;
}

.tmpl-desc {
    font-size: 10px;
    color: var(--color-text-tertiary);
    line-height: 1.4;
}

/* --- Responsive Design --- */
@media (max-width: 1024px) {
    .split-view {
        grid-template-columns: 1fr;
    }

    .story-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 768px) {
    body {
        padding: 0;
    }

    .app {
        flex-direction: column;
        height: auto;
        min-height: 100vh;
        width: 100%;
        border-radius: 0;
        border: none;
    }

    .sb {
        width: 100%;
        min-width: 100%;
        height: auto;
        max-height: 300px;
        border-right: none;
        border-bottom: 1px solid var(--color-border-main);
    }

    .sb-content {
        height: auto;
        max-height: 200px;
    }

    .mc {
        width: 100%;
        min-width: 100%;
        overflow-x: hidden;
    }

    .lang-cards-grid,
    .story-grid,
    .typing-split {
        grid-template-columns: minmax(0, 1fr) !important;
    }

    .lang-toolbar {
        flex-direction: column;
        align-items: flex-start;
    }

    .tb-stats {
        margin-left: 0;
        margin-top: 8px;
    }

    .typing-box {
        border-right: none;
        border-bottom: 1px solid var(--color-border-main);
    }

    .typing-box:last-child {
        border-bottom: none;
    }

    .mc-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .tabs {
        flex-wrap: nowrap;
        overflow-x: auto;
        white-space: nowrap;
        padding: 0 16px;
    }

    .tabs::-webkit-scrollbar {
        height: 0px;
    }

    .panel {
        padding: 16px;
        overflow-x: hidden;
    }

    .split-view {
        min-height: auto;
    }
}