/* ============================================================
   AI Assistant - Modern Clean UI
   Inspired by: Claude, ChatGPT, Linear
   ============================================================ */

:root {
    /* Color Palette - Clean & Professional */
    --bg-base: #ffffff;
    --bg-surface: #f7f8fa;
    --bg-elevated: #ffffff;
    --bg-hover: #f3f4f6;
    --bg-active: #ebedf3;

    --text-primary: #0d0d0d;
    --text-secondary: #525252;
    --text-muted: #a0a0a0;
    --text-placeholder: #c4c4c4;

    --border: #e4e4e7;
    --border-strong: #d1d1d6;

    --accent: #0d0d0d;
    --accent-fg: #ffffff;
    --accent-hover: #262626;

    --green: #12b76a;
    --green-light: #dcfce7;
    --green-fg: #15803d;

    --blue: #2563eb;
    --blue-light: #dbeafe;
    --blue-fg: #1d4ed8;

    --red: #ef4444;
    --red-light: #fee2e2;
    --red-fg: #dc2626;

    --amber: #f59e0b;
    --amber-light: #fef3c7;
    --amber-fg: #b45309;

    /* Shadows */
    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.06), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 10px 10px -5px rgba(0, 0, 0, 0.03);

    /* Typography */
    --font-sans: "Inter", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
    --font-mono: "JetBrains Mono", "SF Mono", "Fira Code", ui-monospace, monospace;

    /* Spacing */
    --space-1: 4px;
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-5: 20px;
    --space-6: 24px;
    --space-8: 32px;
    --space-10: 40px;

    /* Radii */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Transitions */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
    --duration-fast: 120ms;
    --duration-normal: 200ms;
}

/* ============================================================
   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;
    text-rendering: optimizeLegibility;
}

html, body {
    min-height: 100%;
    height: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: 14px;
    line-height: 1.5;
    color: var(--text-primary);
    background: var(--bg-base);
}

a {
    color: inherit;
    text-decoration: none;
}

button, input, select, textarea {
    font: inherit;
    color: inherit;
}

button {
    cursor: pointer;
    background: none;
    border: none;
}

img, svg {
    display: block;
    max-width: 100%;
}

/* ============================================================
   Page Layouts
   ============================================================ */

/* Auth Page */
body.auth-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: var(--space-6);
    background: var(--bg-surface);
}

.auth-shell {
    width: 100%;
    max-width: 420px;
}

.auth-card {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    box-shadow: var(--shadow-lg);
}

.auth-brand {
    margin-bottom: var(--space-6);
}

.auth-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-1) var(--space-3);
    background: var(--green-light);
    color: var(--green-fg);
    font-size: 12px;
    font-weight: 600;
    border-radius: var(--radius-full);
    margin-bottom: var(--space-3);
}

.auth-title {
    font-size: 24px;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.auth-subtitle {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.auth-tabs {
    display: flex;
    gap: var(--space-1);
    padding: var(--space-1);
    background: var(--bg-surface);
    border-radius: var(--radius-md);
    margin: var(--space-6) 0;
}

.auth-tab {
    flex: 1;
    padding: var(--space-2) var(--space-4);
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    transition: all var(--duration-fast) var(--ease-out);
}

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

.auth-tab.active {
    background: var(--bg-elevated);
    color: var(--text-primary);
    box-shadow: var(--shadow-xs);
}

/* Student Page / Chat Interface */
body.student-page {
    height: 100dvh;
    overflow: hidden;
    background: var(--bg-surface);
}

.codex-shell {
    display: flex;
    flex-direction: column;
    height: 100dvh;
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--space-4);
}

.codex-main {
    flex: 1;
    min-height: 0;
    display: flex;
    flex-direction: column;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.codex-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--space-5);
    border-bottom: 1px solid var(--border);
    background: var(--bg-elevated);
}

.toolbar-left {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.toolbar-title {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.toolbar-subtitle {
    font-size: 13px;
    color: var(--text-muted);
}

.toolbar-actions {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

/* Chat Stage */
.codex-chat-stage {
    flex: 1;
    min-height: 0;
    display: grid;
    grid-template-columns: 1fr;
    grid-template-rows: 1fr auto auto;
    gap: var(--space-3);
    padding: var(--space-4) var(--space-5);
    overflow: hidden;
}

.chat-feed {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    padding-right: var(--space-2);
}

.chat-feed::-webkit-scrollbar {
    width: 6px;
}

.chat-feed::-webkit-scrollbar-track {
    background: transparent;
}

.chat-feed::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: var(--radius-full);
}

/* Thinking Panel */
.thinking-panel {
    padding: var(--space-3) var(--space-4);
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    animation: slideIn var(--duration-normal) var(--ease-out);
}

.thinking-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-2);
}

.thinking-label {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.thinking-dots {
    display: flex;
    gap: 4px;
}

.thinking-dots span {
    width: 6px;
    height: 6px;
    background: var(--green);
    border-radius: 50%;
    animation: pulse 1.4s ease-in-out infinite;
}

.thinking-dots span:nth-child(2) { animation-delay: 0.2s; }
.thinking-dots span:nth-child(3) { animation-delay: 0.4s; }

.thinking-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

.thinking-copy {
    font-size: 13px;
    color: var(--text-muted);
    margin-top: var(--space-1);
}

@keyframes pulse {
    0%, 100% { opacity: 0.4; transform: scale(0.8); }
    50% { opacity: 1; transform: scale(1); }
}

@keyframes slideIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Chat Messages */
.chat-message {
    display: flex;
    gap: var(--space-3);
    max-width: 800px;
}

.chat-message.user {
    flex-direction: row-reverse;
    margin-left: auto;
}

.chat-avatar {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 600;
    flex-shrink: 0;
    background: var(--bg-surface);
    color: var(--text-secondary);
    border: 1px solid var(--border);
}

.chat-message.assistant .chat-avatar {
    background: var(--green-light);
    color: var(--green-fg);
    border-color: transparent;
}

.chat-message.user .chat-avatar {
    background: var(--text-primary);
    color: var(--accent-fg);
    border-color: transparent;
}

.chat-bubble {
    flex: 1;
    padding: var(--space-3) var(--space-4);
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}

.chat-message.user .chat-bubble {
    background: var(--text-primary);
    color: var(--accent-fg);
    border-color: var(--text-primary);
}

.chat-meta {
    font-size: 11px;
    color: var(--text-muted);
    margin-bottom: var(--space-2);
}

.chat-message.user .chat-meta {
    color: rgba(255, 255, 255, 0.6);
}

.chat-content {
    font-size: 14px;
    line-height: 1.7;
}

.chat-content p { margin: 0 0 var(--space-3); }
.chat-content p:last-child { margin-bottom: 0; }
.chat-content ul, .chat-content ol { margin: var(--space-3) 0; padding-left: var(--space-5); }
.chat-content li { margin: var(--space-1) 0; }
.chat-content a { color: var(--blue); text-decoration: underline; text-underline-offset: 2px; }
.chat-content code {
    padding: 2px 6px;
    background: var(--bg-hover);
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: 0.9em;
}
.chat-content pre {
    margin: var(--space-3) 0;
    padding: var(--space-3) var(--space-4);
    background: #1a1a1a;
    color: #fafafa;
    border-radius: var(--radius-md);
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 13px;
    line-height: 1.6;
}
.chat-content pre code {
    padding: 0;
    background: none;
    color: inherit;
}
.chat-content blockquote {
    margin: var(--space-3) 0;
    padding-left: var(--space-4);
    border-left: 3px solid var(--border-strong);
    color: var(--text-secondary);
    font-style: italic;
}
.chat-content table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--space-3) 0;
    font-size: 13px;
}
.chat-content th, .chat-content td {
    padding: var(--space-2) var(--space-3);
    border: 1px solid var(--border);
    text-align: left;
}
.chat-content th { background: var(--bg-surface); font-weight: 600; }

/* Composer */
.chat-composer {
    padding: var(--space-3) 0 0;
}

.composer-box {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
    padding: var(--space-3);
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}

.composer-input {
    width: 100%;
    min-height: 24px;
    max-height: 200px;
    padding: 0;
    border: none;
    background: transparent;
    font-size: 14px;
    line-height: 1.6;
    resize: none;
    outline: none;
}

.composer-input::placeholder {
    color: var(--text-placeholder);
}

.composer-actions {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
}

.composer-modes {
    display: flex;
    gap: var(--space-2);
}

.composer-send {
    display: flex;
    gap: var(--space-2);
}

/* Mode Trigger */
.mode-trigger {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--duration-fast) var(--ease-out);
}

.mode-trigger:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.mode-caret {
    font-size: 10px;
    opacity: 0.5;
}

.mode-menu {
    position: absolute;
    bottom: calc(100% + var(--space-2));
    left: 0;
    min-width: 280px;
    padding: var(--space-2);
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    z-index: 100;
    animation: slideUp var(--duration-fast) var(--ease-out);
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

.mode-item {
    width: 100%;
    padding: var(--space-3);
    text-align: left;
    border-radius: var(--radius-md);
    transition: background var(--duration-fast);
}

.mode-item:hover {
    background: var(--bg-hover);
}

.mode-item-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

.mode-item-desc {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 2px;
}

/* Voice Button */
.voice-btn {
    padding: var(--space-2) var(--space-3);
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: all var(--duration-fast) var(--ease-out);
}

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

.voice-btn.listening {
    background: var(--green-light);
    border-color: var(--green);
    color: var(--green-fg);
}

/* ============================================================
   Buttons
   ============================================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    font-size: 13px;
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: all var(--duration-fast) var(--ease-out);
    white-space: nowrap;
}

.btn-primary {
    background: var(--text-primary);
    color: var(--accent-fg);
    border: 1px solid var(--text-primary);
}

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

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

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

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

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

.btn-danger {
    background: var(--red-light);
    color: var(--red-fg);
    border: 1px solid transparent;
}

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

.btn-sm {
    padding: var(--space-1) var(--space-3);
    font-size: 12px;
}

.btn-lg {
    padding: var(--space-3) var(--space-5);
    font-size: 14px;
}

.btn-full {
    width: 100%;
}

/* ============================================================
   Forms
   ============================================================ */

.form-stack {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.form-field {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.form-label {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
}

.form-input {
    width: 100%;
    padding: var(--space-3);
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 14px;
    color: var(--text-primary);
    transition: all var(--duration-fast) var(--ease-out);
}

.form-input:focus {
    outline: none;
    border-color: var(--text-primary);
    box-shadow: 0 0 0 3px rgba(13, 13, 13, 0.08);
}

.form-input::placeholder {
    color: var(--text-placeholder);
}

.form-hint {
    font-size: 12px;
    color: var(--text-muted);
}

.form-help {
    font-size: 12px;
    color: var(--text-muted);
    line-height: 1.5;
}

/* ============================================================
   Admin Layout
   ============================================================ */

body.admin-page {
    background: var(--bg-surface);
}

.admin-shell {
    display: grid;
    grid-template-columns: 260px 1fr;
    min-height: 100vh;
}

.admin-sidebar {
    position: sticky;
    top: 0;
    height: 100vh;
    padding: var(--space-6);
    background: var(--bg-elevated);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

.admin-brand {
    padding-bottom: var(--space-6);
    border-bottom: 1px solid var(--border);
}

.admin-brand-title {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.admin-brand-sub {
    font-size: 13px;
    color: var(--text-muted);
    margin-top: var(--space-1);
}

.admin-nav {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    flex: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--duration-fast) var(--ease-out);
}

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

.nav-item.active {
    background: var(--text-primary);
    color: var(--accent-fg);
}

.nav-icon {
    width: 18px;
    height: 18px;
    opacity: 0.7;
}

.nav-item.active .nav-icon {
    opacity: 1;
}

/* Admin Main */
.admin-main {
    padding: var(--space-6);
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

.admin-topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: var(--space-4);
    border-bottom: 1px solid var(--border);
}

.admin-page-title {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: -0.02em;
}

/* Cards */
.card {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.card-header {
    padding: var(--space-4) var(--space-5);
    border-bottom: 1px solid var(--border);
}

.card-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
}

.card-body {
    padding: var(--space-5);
}

/* Tables */
.table-card {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.table-header {
    padding: var(--space-3) var(--space-4);
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border);
    font-size: 13px;
    font-weight: 600;
    color: var(--text-secondary);
}

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

.table th, .table td {
    padding: var(--space-3) var(--space-4);
    text-align: left;
    border-bottom: 1px solid var(--border);
    font-size: 13px;
}

.table th {
    font-weight: 600;
    color: var(--text-secondary);
    background: var(--bg-surface);
}

.table tr:last-child td {
    border-bottom: none;
}

.table tr:hover td {
    background: var(--bg-hover);
}

/* Summary Strip */
.summary-strip {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-4);
}

.summary-card {
    padding: var(--space-5);
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
}

.summary-label {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.summary-value {
    font-size: 28px;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    margin-top: var(--space-2);
}

/* Status Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: var(--space-1) var(--space-2);
    font-size: 11px;
    font-weight: 600;
    border-radius: var(--radius-full);
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.badge-green {
    background: var(--green-light);
    color: var(--green-fg);
}

.badge-blue {
    background: var(--blue-light);
    color: var(--blue-fg);
}

.badge-red {
    background: var(--red-light);
    color: var(--red-fg);
}

.badge-amber {
    background: var(--amber-light);
    color: var(--amber-fg);
}

.badge-gray {
    background: var(--bg-surface);
    color: var(--text-muted);
}

/* Flash Messages */
.flash-stack {
    position: fixed;
    top: var(--space-4);
    right: var(--space-4);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.flash {
    padding: var(--space-3) var(--space-4);
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    font-size: 13px;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    animation: slideIn var(--duration-normal) var(--ease-out);
}

.flash-success {
    background: var(--green-light);
    border-color: var(--green);
    color: var(--green-fg);
}

.flash-error {
    background: var(--red-light);
    border-color: var(--red);
    color: var(--red-fg);
}

.flash-warning {
    background: var(--amber-light);
    border-color: var(--amber);
    color: var(--amber-fg);
}

/* ============================================================
   Live2D Coach Widget
   ============================================================ */

.coach-widget {
    position: relative;
    width: 200px;
    height: 320px;
    margin-left: auto;
}

.coach-stage {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    position: relative;
}

.coach-figure {
    position: relative;
    animation: gentleFloat 4s ease-in-out infinite;
}

@keyframes gentleFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.coach-shadow {
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    height: 24px;
    background: radial-gradient(ellipse at center, rgba(0, 0, 0, 0.15) 0%, transparent 70%);
    filter: blur(8px);
}

/* ============================================================
   Quiz Components
   ============================================================ */

.quiz-card {
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-5);
}

.quiz-header {
    margin-bottom: var(--space-4);
}

.quiz-kicker {
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-bottom: var(--space-2);
}

.quiz-title {
    font-size: 18px;
    font-weight: 700;
    letter-spacing: -0.01em;
    color: var(--text-primary);
}

.quiz-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    margin-top: var(--space-3);
}

.quiz-tag {
    padding: var(--space-1) var(--space-2);
    background: var(--bg-surface);
    border-radius: var(--radius-sm);
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
}

.quiz-question {
    padding: var(--space-4);
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-4);
}

.quiz-stem {
    font-size: 15px;
    line-height: 1.7;
    color: var(--text-primary);
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.quiz-option {
    display: flex;
    align-items: flex-start;
    gap: var(--space-3);
    padding: var(--space-3);
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--duration-fast) var(--ease-out);
}

.quiz-option:hover {
    border-color: var(--border-strong);
    background: var(--bg-hover);
}

.quiz-option.selected {
    border-color: var(--text-primary);
    background: var(--bg-surface);
}

.quiz-option.correct {
    border-color: var(--green);
    background: var(--green-light);
}

.quiz-option.incorrect {
    border-color: var(--red);
    background: var(--red-light);
}

.quiz-option-label {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-surface);
    border-radius: var(--radius-sm);
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    flex-shrink: 0;
}

.quiz-option.correct .quiz-option-label {
    background: var(--green);
    color: white;
}

.quiz-option.incorrect .quiz-option-label {
    background: var(--red);
    color: white;
}

.quiz-option-text {
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-primary);
}

/* ============================================================
   Responsive
   ============================================================ */

@media (max-width: 1024px) {
    .admin-shell {
        grid-template-columns: 1fr;
    }

    .admin-sidebar {
        position: static;
        height: auto;
        border-right: none;
        border-bottom: 1px solid var(--border);
    }

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

@media (max-width: 768px) {
    body.auth-page {
        padding: var(--space-4);
    }

    .auth-card {
        padding: var(--space-6);
    }

    .codex-shell {
        padding: var(--space-2);
    }

    .codex-toolbar {
        padding: var(--space-3) var(--space-4);
    }

    .codex-chat-stage {
        padding: var(--space-3) var(--space-4);
    }

    .chat-message {
        max-width: 100%;
    }

    .summary-strip {
        grid-template-columns: 1fr;
    }
}

/* ============================================================
   Legacy Class Aliases (for existing templates)
   ============================================================ */

/* Buttons */
.ghost-btn, .ghost-mini { display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2); padding: var(--space-2) var(--space-4); font-size: 13px; font-weight: 500; border-radius: var(--radius-md); border: 1px solid var(--border); background: transparent; color: var(--text-secondary); transition: all var(--duration-fast) var(--ease-out); cursor: pointer; }
.ghost-btn:hover, .ghost-mini:hover { background: var(--bg-hover); color: var(--text-primary); border-color: var(--border-strong); }
.secondary-btn, .outline-link, .button-like, .chat-fullscreen-btn { display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2); padding: var(--space-2) var(--space-4); font-size: 13px; font-weight: 500; border-radius: var(--radius-md); border: 1px solid var(--border); background: var(--bg-surface); color: var(--text-secondary); transition: all var(--duration-fast) var(--ease-out); cursor: pointer; }
.secondary-btn:hover, .outline-link:hover, .button-like:hover, .chat-fullscreen-btn:hover { background: var(--bg-hover); color: var(--text-primary); }
.chat-fullscreen-btn { font-size: 12px; padding: var(--space-1) var(--space-3); }
.primary-btn { display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2); padding: var(--space-2) var(--space-4); font-size: 13px; font-weight: 500; border-radius: var(--radius-md); border: 1px solid var(--text-primary); background: var(--text-primary); color: var(--accent-fg); transition: all var(--duration-fast) var(--ease-out); cursor: pointer; }
.primary-btn:hover { background: var(--accent-hover); border-color: var(--accent-hover); }

/* Layout */
.studio-shell { display: flex; flex-direction: column; height: 100dvh; max-width: 1400px; margin: 0 auto; padding: var(--space-4); }
.studio-main, .chat-only-main { flex: 1; min-height: 0; display: flex; flex-direction: column; background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-xl); box-shadow: var(--shadow-lg); overflow: hidden; }
.glass-card { background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-lg); overflow: hidden; }
.main-toolbar, .codex-toolbar { display: flex; align-items: center; justify-content: space-between; padding: var(--space-4) var(--space-5); border-bottom: 1px solid var(--border); background: var(--bg-elevated); }

/* Chat */
.chat-stage { flex: 1; min-height: 0; display: grid; grid-template-columns: 1fr; grid-template-rows: 1fr auto auto; gap: var(--space-3); padding: var(--space-4) var(--space-5); overflow: hidden; }
.chat-feed { flex: 1; min-height: 0; overflow-y: auto; display: flex; flex-direction: column; gap: var(--space-4); padding-right: var(--space-2); }
.chat-message { display: flex; gap: var(--space-3); max-width: 800px; }
.chat-message-user, .chat-message.user { flex-direction: row-reverse; margin-left: auto; }
.chat-message-user .chat-avatar { background: var(--text-primary); color: var(--accent-fg); border-color: transparent; }
.chat-message-assistant .chat-avatar { background: var(--green-light); color: var(--green-fg); border-color: transparent; }
.chat-bubble { flex: 1; padding: var(--space-3) var(--space-4); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-lg); }
.chat-message-user .chat-bubble, .chat-message.user .chat-bubble { background: var(--text-primary); color: var(--accent-fg); border-color: var(--text-primary); }
.chat-meta-row { margin-bottom: var(--space-2); }
.chat-meta { font-size: 11px; color: var(--text-muted); margin-bottom: var(--space-2); }
.chat-message-user .chat-meta { color: rgba(255, 255, 255, 0.6); }
.preformatted, .rendered-content { font-size: 14px; line-height: 1.7; }
.preformatted p, .rendered-content p { margin: 0 0 var(--space-3); }
.preformatted p:last-child, .rendered-content p:last-child { margin-bottom: 0; }
.preformatted pre, .rendered-content pre { margin: var(--space-3) 0; padding: var(--space-3) var(--space-4); background: #1a1a1a; color: #fafafa; border-radius: var(--radius-md); overflow-x: auto; font-family: var(--font-mono); font-size: 13px; line-height: 1.6; }
.thinking-panel-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--space-2); }
.thinking-panel-badge { display: flex; align-items: center; gap: var(--space-2); }
.thinking-panel-label { font-size: 12px; font-weight: 600; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.05em; }
.thinking-panel-title { font-size: 14px; font-weight: 600; color: var(--text-primary); }
.thinking-panel-copy { font-size: 13px; color: var(--text-muted); margin-top: var(--space-1); }
.thinking-panel-timer { font-size: 12px; color: var(--text-muted); font-weight: 500; }
.chat-composer { padding-top: var(--space-3); }
.composer-box { display: flex; flex-direction: column; gap: var(--space-3); padding: var(--space-3); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-lg); }
#chat-input, .chat-input { width: 100%; min-height: 24px; max-height: 200px; padding: 0; border: none; background: transparent; font-size: 14px; line-height: 1.6; resize: none; outline: none; }
.composer-actions { display: flex; align-items: center; justify-content: space-between; gap: var(--space-3); }
.composer-mode { position: relative; }
.composer-action-buttons { display: flex; gap: var(--space-2); }
.mode-trigger { display: inline-flex; align-items: center; gap: var(--space-2); padding: var(--space-2) var(--space-3); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-md); font-size: 13px; font-weight: 500; color: var(--text-secondary); transition: all var(--duration-fast) var(--ease-out); }
.mode-trigger-label { font-size: 13px; font-weight: 500; }
.mode-trigger-caret { font-size: 10px; opacity: 0.5; }
.mode-menu { position: absolute; bottom: calc(100% + var(--space-2)); left: 0; min-width: 280px; padding: var(--space-2); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-lg); box-shadow: var(--shadow-xl); z-index: 100; }
.mode-menu-item { width: 100%; padding: var(--space-3); text-align: left; border-radius: var(--radius-md); transition: background var(--duration-fast); }
.mode-menu-title { font-size: 14px; font-weight: 600; color: var(--text-primary); }
.mode-menu-copy { font-size: 12px; color: var(--text-muted); margin-top: 2px; }
.voice-status-hint { margin-top: var(--space-2); padding: var(--space-2) var(--space-3); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); font-size: 12px; color: var(--text-muted); }

/* Coach / Live2D */
.coach-widget { position: relative; width: 200px; height: 320px; }
.coach-stage-shell { width: 100%; height: 100%; background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-xl); overflow: hidden; position: relative; }
.coach-live2d-stage { width: 100%; height: 100%; background: transparent; }
.coach-live2d-stage canvas { background: transparent !important; }
.coach-fallback-note { display: grid; place-items: center; width: 100%; height: 100%; padding: var(--space-4); color: var(--text-muted); font-size: 13px; text-align: center; }
.coach-record-item { padding: var(--space-3); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); }
.coach-help-item { padding: var(--space-3); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); }
.coach-assistant-card { padding: var(--space-4); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-lg); }
.coach-assistant-topline { font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-muted); margin-bottom: var(--space-2); }
.coach-assistant-heading { font-size: 18px; font-weight: 700; letter-spacing: -0.01em; color: var(--text-primary); margin-bottom: var(--space-2); }
.coach-assistant-subtitle { font-size: 14px; color: var(--text-secondary); line-height: 1.6; }
.coach-status-pill { display: inline-flex; align-items: center; padding: var(--space-1) var(--space-2); background: var(--green-light); color: var(--green-fg); border-radius: var(--radius-full); font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.04em; }
.coach-student-pill { display: inline-flex; align-items: center; padding: var(--space-1) var(--space-2); background: var(--blue-light); color: var(--blue-fg); border-radius: var(--radius-full); font-size: 12px; font-weight: 500; }
.coach-student-pill.is-muted { background: var(--bg-hover); color: var(--text-muted); }
.coach-record-list, .coach-help-list, .coach-student-options { display: flex; flex-direction: column; gap: var(--space-2); margin-top: var(--space-3); }
.coach-record-item-head { display: flex; justify-content: space-between; margin-bottom: var(--space-2); font-size: 12px; color: var(--text-muted); }
.coach-record-item-body, .coach-help-item { font-size: 14px; line-height: 1.6; color: var(--text-primary); }
.coach-inline-note { padding: var(--space-3); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); font-size: 13px; color: var(--text-secondary); line-height: 1.6; }

/* Quiz */
.quiz-explain-card { padding: var(--space-4); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-lg); }
.quiz-explain-topline { font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-muted); margin-bottom: var(--space-2); }
.quiz-explain-header { display: flex; justify-content: space-between; align-items: flex-start; gap: var(--space-4); margin-bottom: var(--space-3); }
.quiz-explain-heading { font-size: 18px; font-weight: 700; letter-spacing: -0.01em; color: var(--text-primary); }
.quiz-explain-subtitle { font-size: 14px; color: var(--text-secondary); line-height: 1.6; margin-top: var(--space-2); }
.quiz-explain-meta { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-top: var(--space-3); }
.quiz-meta-pill, .quiz-query-pill, .quiz-inline-tag { display: inline-flex; align-items: center; padding: var(--space-1) var(--space-2); background: var(--blue-light); color: var(--blue-fg); border-radius: var(--radius-full); font-size: 11px; font-weight: 600; }
.quiz-panel { padding: var(--space-4); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); }
.quiz-panel-question { background: var(--bg-surface); }
.quiz-panel-kicker, .quiz-section-title, .quiz-inline-block-title { font-size: 12px; font-weight: 600; color: var(--text-muted); letter-spacing: 0.04em; }
.quiz-question-stem { font-size: 15px; line-height: 1.7; color: var(--text-primary); margin-top: var(--space-2); }
.quiz-option-list { display: flex; flex-direction: column; gap: var(--space-2); margin-top: var(--space-3); }
.quiz-option-row { display: grid; grid-template-columns: 32px 1fr; gap: var(--space-3); padding: var(--space-3); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-md); }
.quiz-option-label { display: inline-flex; align-items: center; justify-content: center; width: 28px; height: 28px; background: var(--blue-light); color: var(--blue-fg); border-radius: var(--radius-sm); font-size: 12px; font-weight: 700; }
.quiz-option-body { font-size: 14px; line-height: 1.6; color: var(--text-primary); }
.quiz-answer-box { display: inline-flex; align-items: center; gap: var(--space-2); padding: var(--space-2) var(--space-3); background: var(--green-light); color: var(--green-fg); border-radius: var(--radius-md); font-size: 13px; font-weight: 600; margin-top: var(--space-3); }
.quiz-answer-label { font-size: 10px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; }
.quiz-answer-value { font-size: 16px; font-weight: 700; }
.quiz-info-grid, .quiz-vocab-grid, .quiz-candidate-list, .quiz-resource-grid, .quiz-related-grid { display: grid; gap: var(--space-3); margin-top: var(--space-3); }
.quiz-info-card, .quiz-vocab-card, .quiz-candidate-item, .quiz-resource-card, .quiz-related-card { padding: var(--space-3); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-md); }
.quiz-info-label { font-size: 11px; font-weight: 600; color: var(--text-muted); letter-spacing: 0.04em; }
.quiz-info-value { font-size: 14px; color: var(--text-secondary); margin-top: var(--space-1); }
.quiz-vocab-title { font-size: 16px; font-weight: 700; color: var(--text-primary); }
.quiz-resource-title, .quiz-related-title { font-size: 14px; font-weight: 600; color: var(--text-primary); }
.quiz-resource-meta { font-size: 11px; font-weight: 600; color: var(--text-muted); margin-top: var(--space-1); }
.quiz-resource-body, .quiz-related-body, .quiz-related-translation { font-size: 13px; color: var(--text-secondary); margin-top: var(--space-2); line-height: 1.6; }
.quiz-related-translation { padding-top: var(--space-2); border-top: 1px dashed var(--border); color: var(--text-muted); }
.quiz-vocab-meta { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-top: var(--space-2); }
.quiz-vocab-ipa, .quiz-vocab-pos, .quiz-vocab-def { display: inline-flex; align-items: center; padding: var(--space-1) var(--space-2); background: var(--bg-surface); border-radius: var(--radius-sm); font-size: 11px; font-weight: 500; color: var(--text-secondary); }
.quiz-vocab-example { font-size: 13px; color: var(--text-secondary); margin-top: var(--space-2); }
.quiz-vocab-example-cn { color: var(--text-muted); }
.quiz-candidate-id { font-size: 11px; font-weight: 600; color: var(--text-muted); }
.quiz-candidate-text { font-size: 13px; color: var(--text-secondary); margin-top: var(--space-1); }
.quiz-help-list { display: flex; flex-direction: column; gap: var(--space-2); }
.quiz-query-label { font-weight: 600; color: var(--text-primary); }
.quiz-empty-note { color: var(--text-muted); font-size: 13px; }
.quiz-explain-footer { font-size: 13px; color: var(--text-muted); margin-top: var(--space-3); }

/* Admin Layout */
.admin-shell { display: grid; grid-template-columns: 260px 1fr; min-height: 100vh; }
.admin-sidebar { position: sticky; top: 0; height: 100vh; padding: var(--space-6); background: var(--bg-elevated); border-right: 1px solid var(--border); display: flex; flex-direction: column; gap: var(--space-6); }
.admin-brand { padding-bottom: var(--space-6); border-bottom: 1px solid var(--border); }
.admin-brand h1 { font-size: 20px; font-weight: 700; letter-spacing: -0.02em; color: var(--text-primary); }
.admin-brand p { font-size: 13px; color: var(--text-muted); margin-top: var(--space-1); }
.admin-nav { display: flex; flex-direction: column; gap: var(--space-1); }
.nav-link { display: flex; align-items: center; min-height: 44px; padding: 0 var(--space-3); font-size: 14px; font-weight: 500; color: var(--text-secondary); border-radius: var(--radius-md); transition: all var(--duration-fast) var(--ease-out); }
.nav-link:hover { background: var(--bg-hover); color: var(--text-primary); }
.nav-link.active { background: var(--text-primary); color: var(--accent-fg); }
.admin-main { padding: var(--space-6); display: flex; flex-direction: column; gap: var(--space-6); }
.admin-topbar { display: flex; align-items: center; justify-content: space-between; padding-bottom: var(--space-4); border-bottom: 1px solid var(--border); }
.admin-content-grid { display: grid; grid-template-columns: 320px 1fr; gap: var(--space-6); }
.list-panel, .form-panel { background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: var(--space-5); }
.student-list, .log-stack, .reply-script-list { display: flex; flex-direction: column; gap: var(--space-2); }
.student-list-item { display: flex; justify-content: space-between; padding: var(--space-3); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-md); transition: all var(--duration-fast); }
.student-list-item:hover { background: var(--bg-hover); }
.student-list-item.active { border-color: var(--text-primary); background: var(--bg-surface); }
.student-list-item span, .student-list-item em { font-size: 13px; color: var(--text-secondary); }
.student-list-meta { text-align: right; }
.admin-sidebar .status-card { padding: var(--space-4); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); }
.status-row { display: flex; justify-content: space-between; padding: var(--space-2) 0; }
.status-row + .status-row { border-top: 1px solid var(--border); }
.status-row span { font-size: 13px; color: var(--text-muted); }
.status-row strong { font-size: 13px; font-weight: 600; color: var(--text-primary); }
.summary-strip { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-4); }
.summary-strip article { padding: var(--space-4); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-lg); }
.summary-strip span { font-size: 12px; font-weight: 500; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; }
.summary-strip strong { display: block; font-size: 28px; font-weight: 700; letter-spacing: -0.02em; color: var(--text-primary); margin-top: var(--space-2); }
.toggle-row { display: flex; justify-content: space-between; align-items: center; padding: var(--space-3) 0; border-bottom: 1px solid var(--border); }
.toggle-row:last-child { border-bottom: none; }
.toggle-row strong { font-size: 14px; font-weight: 600; color: var(--text-primary); }
.toggle-row p { font-size: 13px; color: var(--text-muted); }
.log-entry { padding: var(--space-3); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); border-left: 3px solid var(--border-strong); }
.log-entry-user { border-left-color: var(--blue); }
.log-entry-assistant { border-left-color: var(--green); }
.reply-script-head { display: flex; justify-content: space-between; margin-bottom: var(--space-2); }
.reply-script-head span { font-size: 11px; color: var(--text-muted); }
.bubble-meta { display: flex; justify-content: space-between; margin-bottom: var(--space-2); }
.bubble-meta span { font-size: 11px; color: var(--text-muted); }
.content-block { padding: var(--space-4); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); }
.info-tile { padding: var(--space-4); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); }
.student-card { padding: var(--space-4); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-md); }
.focus-card { padding: var(--space-4); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-md); }
.metric-card { padding: var(--space-4); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-md); }
.status-banner { padding: var(--space-3); background: var(--green-light); border: 1px solid var(--green); border-radius: var(--radius-md); color: var(--green-fg); font-size: 13px; font-weight: 500; margin-top: var(--space-3); }
.status-banner.is-error { background: var(--red-light); border-color: var(--red); color: var(--red-fg); }
.section-box { padding: var(--space-4); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); }
.empty-state { padding: var(--space-6); background: var(--bg-surface); border: 1px dashed var(--border); border-radius: var(--radius-md); text-align: center; }
.empty-state h2 { font-size: 16px; font-weight: 600; color: var(--text-primary); margin-bottom: var(--space-2); }
.empty-state p { font-size: 13px; color: var(--text-muted); }
.student-summary-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-3); margin-top: var(--space-4); }
.student-profile-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-3); margin-top: var(--space-4); }
.student-detail-records { margin-top: var(--space-4); padding-top: var(--space-3); border-top: 1px dashed var(--border); }
.student-detail-records-head { display: flex; align-items: baseline; justify-content: space-between; gap: var(--space-3); margin-bottom: var(--space-3); }
.student-detail-records-head strong { font-size: 14px; font-weight: 700; color: var(--text-primary); }
.student-detail-records-head span { font-size: 12px; color: var(--text-muted); }
.student-detail-records .coach-record-admin-list { display: flex; flex-direction: column; gap: var(--space-3); }
.student-detail-records .coach-record-admin-item { padding: var(--space-3); }
.form-grid-two { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-4); }
.field-wide { grid-column: 1 / -1; }
.form-actions, .wrap-actions, .table-actions, .inline-input-row { display: flex; gap: var(--space-3); align-items: center; flex-wrap: wrap; margin-top: var(--space-4); }
.inline-form { display: flex; justify-content: space-between; gap: var(--space-4); align-items: center; padding: var(--space-3) 0; border-bottom: 1px solid var(--border); }
.inline-input-row { display: flex; gap: var(--space-3); align-items: center; }
.muted-box { background: var(--bg-surface); padding: var(--space-3); border-radius: var(--radius-md); }
.content-wide { grid-column: 1 / -1; }
.inline-input-row select, .inline-input-row input { padding: var(--space-2) var(--space-3); border: 1px solid var(--border); border-radius: var(--radius-md); font-size: 13px; background: var(--bg-elevated); color: var(--text-primary); }

/* Misc */
.field { display: flex; flex-direction: column; gap: var(--space-2); }
.field span, .field label { font-size: 13px; font-weight: 500; color: var(--text-primary); }
.field-help { font-size: 12px; color: var(--text-muted); line-height: 1.5; }
.field-hint { font-size: 12px; color: var(--text-muted); }
.hero-chip { display: inline-flex; align-items: center; padding: var(--space-1) var(--space-3); background: var(--green-light); color: var(--green-fg); border-radius: var(--radius-full); font-size: 12px; font-weight: 600; }
.section-tag { display: inline-flex; align-items: center; padding: var(--space-1) var(--space-3); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-full); font-size: 12px; font-weight: 500; color: var(--text-secondary); }
.auth-kicker { display: inline-flex; align-items: center; padding: var(--space-1) var(--space-3); background: var(--green-light); color: var(--green-fg); border-radius: var(--radius-full); font-size: 12px; font-weight: 600; }
.card-heading h2, .panel-heading h2 { font-size: 18px; font-weight: 700; letter-spacing: -0.01em; color: var(--text-primary); margin-bottom: var(--space-2); }
.card-heading p, .panel-heading p { font-size: 13px; color: var(--text-muted); }
.chat-stage.no-coach { grid-template-columns: 1fr !important; }
.coach-widget.is-unavailable { display: none; }

/* Sidebar blocks */
.sidebar-block { padding: var(--space-4); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-md); }
.sidebar-block-title { font-size: 11px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-muted); margin-bottom: var(--space-3); }
.sidebar-info-list { display: flex; flex-direction: column; gap: var(--space-2); }
.sidebar-info-list > div { display: flex; justify-content: space-between; gap: var(--space-3); }
.sidebar-info-list span { font-size: 12px; color: var(--text-muted); }
.sidebar-info-list strong { font-size: 13px; font-weight: 600; color: var(--text-primary); text-align: right; }
.sidebar-metric-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-2); }
.sidebar-metric-grid article { padding: var(--space-3); background: var(--bg-hover); border-radius: var(--radius-sm); }
.sidebar-metric-grid span { display: block; font-size: 11px; color: var(--text-muted); }
.sidebar-metric-grid strong { display: block; font-size: 16px; font-weight: 700; color: var(--text-primary); margin-top: var(--space-1); }
.sidebar-prompt-list { display: flex; flex-direction: column; gap: var(--space-2); }
.prompt-chip { display: inline-flex; padding: var(--space-2) var(--space-3); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-md); font-size: 13px; font-weight: 500; color: var(--text-secondary); cursor: pointer; transition: all var(--duration-fast); }
.prompt-chip:hover { background: var(--bg-hover); color: var(--text-primary); }
.sidebar-actions { display: flex; flex-direction: column; gap: var(--space-2); }
.sidebar-scroll { min-height: 0; overflow-y: auto; display: flex; flex-direction: column; gap: var(--space-4); }
.sidebar-header { display: flex; justify-content: space-between; align-items: flex-start; gap: var(--space-4); }
.sidebar-header h1 { font-size: 20px; font-weight: 700; letter-spacing: -0.02em; color: var(--text-primary); }
.sidebar-header p { font-size: 13px; color: var(--text-muted); }
.sidebar-toggle-btn, .sidebar-open-btn { display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2); font-size: 13px; font-weight: 500; border-radius: var(--radius-md); border: 1px solid var(--border); background: var(--bg-surface); color: var(--text-secondary); transition: all var(--duration-fast) var(--ease-out); cursor: pointer; padding: var(--space-2) !important; min-height: unset !important; }
.sidebar-toggle-btn:hover, .sidebar-open-btn:hover { background: var(--bg-hover); color: var(--text-primary); }
.main-toolbar-left { display: flex; align-items: center; gap: var(--space-3); }
.main-toolbar-copy { display: flex; flex-direction: column; gap: 2px; }
.main-toolbar-copy strong { font-size: 16px; font-weight: 700; color: var(--text-primary); }
.main-toolbar-copy span { font-size: 13px; color: var(--text-muted); }
.toolbar-actions { display: flex; align-items: center; gap: var(--space-2); }
.context-pill { display: inline-flex; align-items: center; padding: var(--space-2) var(--space-3); background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-full); font-size: 13px; font-weight: 500; color: var(--text-secondary); }
.ai-layout { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-6); }
.content-library-grid { display: grid; grid-template-columns: 320px 1fr; gap: var(--space-6); }
.search-select-group { display: flex; flex-direction: column; gap: var(--space-2); }

/* Coach states */
.coach-widget.state-idle .coach-figure,
.coach-widget.state-thinking .coach-figure,
.coach-widget.state-speaking .coach-figure { animation: gentleFloat 4s ease-in-out infinite; }
@keyframes gentleFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-6px); }
}
.coach-watermark-guard { display: none; }
.coach-media { object-fit: contain; object-position: center bottom; background: transparent; user-select: none; }
.coach-media.is-hidden, .coach-live2d-stage.is-hidden { display: none; }

/* Thinking dots animation */
.thinking-dots span { animation: thinkingPulse 1.4s ease-in-out infinite; }
.thinking-dots span:nth-child(2) { animation-delay: 0.2s; }
.thinking-dots span:nth-child(3) { animation-delay: 0.4s; }
@keyframes thinkingPulse {
    0%, 80%, 100% { opacity: 0.4; transform: scale(0.8); }
    40% { opacity: 1; transform: scale(1); }
}

/* Thinking panel states */
.thinking-panel.is-visible { opacity: 1; transform: translateY(0); }
.thinking-panel { opacity: 0; transform: translateY(8px); transition: opacity var(--duration-normal) var(--ease-out), transform var(--duration-normal) var(--ease-out); }
.thinking-panel[hidden] { display: none !important; }
.chat-bubble.is-pending .preformatted { display: inline-flex; align-items: center; gap: var(--space-2); }

/* Mode menu visibility */
.mode-menu.is-visible { opacity: 1; transform: translateY(0); }
.mode-menu { opacity: 0; transform: translateY(8px); transition: opacity var(--duration-fast) var(--ease-out), transform var(--duration-fast) var(--ease-out); pointer-events: none; }
.mode-menu.is-visible { pointer-events: auto; }

/* Status pills */
.status-pill { display: inline-flex; align-items: center; padding: var(--space-1) var(--space-2); border-radius: var(--radius-full); font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; }
.status-pill-completed { background: var(--green-light); color: var(--green-fg); }
.status-pill-running { background: var(--blue-light); color: var(--blue-fg); }
.status-pill-failed { background: var(--red-light); color: var(--red-fg); }

/* Admin shell sidebar collapsed */
.studio-shell.sidebar-collapsed { grid-template-columns: 0 1fr !important; }
.studio-shell.sidebar-collapsed .studio-sidebar { opacity: 0; pointer-events: none; }
.studio-shell.sidebar-collapsed .sidebar-open-btn { display: inline-flex !important; }

/* Flash messages */
.flash { padding: var(--space-3) var(--space-4); background: var(--bg-elevated); border: 1px solid var(--border); border-radius: var(--radius-md); font-size: 13px; font-weight: 500; box-shadow: var(--shadow-lg); }
.flash-error { background: var(--red-light); border-color: var(--red); color: var(--red-fg); }
.flash-success { background: var(--green-light); border-color: var(--green); color: var(--green-fg); }

/* Simple table */
.simple-table { width: 100%; border-collapse: collapse; }
.simple-table th, .simple-table td { padding: var(--space-3); text-align: left; border-bottom: 1px solid var(--border); font-size: 13px; }
.simple-table th { font-size: 12px; font-weight: 600; color: var(--text-muted); background: var(--bg-surface); text-transform: uppercase; letter-spacing: 0.04em; }
.simple-table tr:last-child td { border-bottom: none; }
.table-title { padding: var(--space-3) var(--space-4); font-weight: 600; background: var(--bg-surface); border-bottom: 1px solid var(--border); font-size: 14px; color: var(--text-primary); }

/* @extend polyfill for legacy aliases */
.btn-ghost { display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2); padding: var(--space-2) var(--space-4); font-size: 13px; font-weight: 500; border-radius: var(--radius-md); border: 1px solid var(--border); background: transparent; color: var(--text-secondary); transition: all var(--duration-fast) var(--ease-out); cursor: pointer; }
.btn-ghost:hover { background: var(--bg-hover); color: var(--text-primary); }
.btn-secondary { display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2); padding: var(--space-2) var(--space-4); font-size: 13px; font-weight: 500; border-radius: var(--radius-md); border: 1px solid var(--border); background: var(--bg-surface); color: var(--text-secondary); transition: all var(--duration-fast) var(--ease-out); cursor: pointer; }
.btn-secondary:hover { background: var(--bg-hover); color: var(--text-primary); }
.btn-primary { display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2); padding: var(--space-2) var(--space-4); font-size: 13px; font-weight: 500; border-radius: var(--radius-md); border: 1px solid var(--text-primary); background: var(--text-primary); color: var(--accent-fg); transition: all var(--duration-fast) var(--ease-out); cursor: pointer; }
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }

/* Responsive adjustments */
@media (max-width: 1200px) {
    .admin-shell { grid-template-columns: 1fr; }
    .admin-sidebar { position: static; height: auto; border-right: none; border-bottom: 1px solid var(--border); }
    .admin-content-grid, .ai-layout, .content-library-grid { grid-template-columns: 1fr; }
    .summary-strip { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 980px) {
    .studio-shell { grid-template-columns: 1fr !important; }
    .chat-stage { grid-template-columns: 1fr !important; }
}

@media (max-width: 860px) {
    .codex-shell, .admin-shell { padding: var(--space-3); }
    .auth-card, .list-panel, .form-panel { padding: var(--space-4); }
}

body.auth-page,
body.student-page,
body.admin-page {
    background:
        radial-gradient(900px 500px at 0% 0%, rgba(37, 99, 235, 0.08), transparent 60%),
        radial-gradient(900px 500px at 100% 0%, rgba(18, 183, 106, 0.08), transparent 60%),
        linear-gradient(180deg, #fafbfd 0%, #f4f6fb 100%);
}

.full-width {
    width: 100%;
}

.stack-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.field input,
.field select,
.field textarea,
.field input[type="file"],
.inline-input-row input,
.inline-input-row select {
    width: 100%;
    min-height: 44px;
    padding: 11px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.92);
    color: var(--text-primary);
    transition: border-color var(--duration-fast) var(--ease-out), box-shadow var(--duration-fast) var(--ease-out), background var(--duration-fast) var(--ease-out);
}

.field textarea {
    min-height: 120px;
    resize: vertical;
}

.field input:focus,
.field select:focus,
.field textarea:focus,
.inline-input-row input:focus,
.inline-input-row select:focus {
    outline: none;
    border-color: rgba(37, 99, 235, 0.45);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.12);
    background: #ffffff;
}

.field input[type="file"] {
    padding: 10px 12px;
}

.field code,
.auth-codex-tip code,
.auth-codex-subtitle code {
    display: inline-block;
    padding: 2px 6px;
    border-radius: 6px;
    background: var(--bg-surface);
    border: 1px solid var(--border);
    font-family: var(--font-mono);
    font-size: 12px;
}

.auth-codex-shell {
    width: min(1040px, 100%);
    display: grid;
    grid-template-columns: minmax(0, 1.15fr) minmax(360px, 0.85fr);
    gap: 24px;
    align-items: stretch;
}

.auth-codex-panel {
    background: rgba(255, 255, 255, 0.82);
    border: 1px solid rgba(228, 228, 231, 0.9);
    border-radius: 24px;
    box-shadow: 0 24px 60px rgba(15, 23, 42, 0.08);
    backdrop-filter: blur(16px);
}

.auth-codex-hero {
    padding: 40px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 14px;
    background:
        radial-gradient(560px 260px at 0% 0%, rgba(37, 99, 235, 0.1), transparent 70%),
        linear-gradient(180deg, rgba(255, 255, 255, 0.88) 0%, rgba(248, 250, 252, 0.88) 100%);
}

.auth-codex-badge,
.auth-codex-kicker {
    display: inline-flex;
    align-items: center;
    width: fit-content;
    padding: 6px 12px;
    border-radius: 999px;
    background: rgba(37, 99, 235, 0.1);
    color: var(--blue-fg);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.auth-codex-title {
    font-size: clamp(30px, 4vw, 44px);
    line-height: 1.05;
    font-weight: 800;
    letter-spacing: -0.04em;
    color: #0f172a;
}

.auth-codex-subtitle {
    max-width: 52ch;
    font-size: 15px;
    line-height: 1.8;
    color: #475569;
}

.auth-codex-form-panel {
    padding: 32px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.auth-codex-form-head {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 24px;
}

.auth-codex-form-head h2 {
    font-size: 28px;
    line-height: 1.1;
    letter-spacing: -0.03em;
    color: #0f172a;
}

.auth-codex-form-head p,
.auth-codex-tip {
    font-size: 13px;
    line-height: 1.7;
    color: #64748b;
}

.auth-codex-form .primary-btn {
    min-height: 46px;
    margin-top: 4px;
}

.studio-shell.studio-shell-chat-only,
.studio-shell {
    max-width: 1600px;
    padding: 20px;
}

.studio-main.glass-card.chat-only-main,
.codex-chat-main {
    background: rgba(255, 255, 255, 0.82);
    border: 1px solid rgba(228, 228, 231, 0.9);
    box-shadow: 0 28px 70px rgba(15, 23, 42, 0.1);
    backdrop-filter: blur(18px);
}

.main-toolbar.chat-only-toolbar,
.main-toolbar,
.codex-toolbar {
    padding: 18px 22px;
    background: rgba(255, 255, 255, 0.78);
    backdrop-filter: blur(10px);
}

.main-toolbar-copy strong {
    font-size: 18px;
    font-weight: 800;
    letter-spacing: -0.03em;
}

.main-toolbar-copy span {
    color: #64748b;
}

.chat-stage,
.codex-chat-stage {
    grid-template-columns: minmax(0, 1fr) 290px;
    grid-template-rows: minmax(0, 1fr) auto auto;
    grid-template-areas:
        "feed coach"
        "thinking coach"
        "composer coach";
    align-items: stretch;
    gap: 18px;
}

.chat-stage.no-coach,
.codex-chat-stage.no-coach {
    grid-template-columns: 1fr !important;
    grid-template-areas:
        "feed"
        "thinking"
        "composer";
}

.chat-feed {
    grid-area: feed;
    padding-right: 6px;
}

.coach-widget {
    grid-area: coach;
    width: 100%;
    height: auto;
    min-height: 100%;
    display: flex;
}

.coach-stage-shell {
    width: 100%;
    min-height: 100%;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding: 20px;
    background:
        radial-gradient(320px 200px at 50% 15%, rgba(37, 99, 235, 0.12), transparent 75%),
        linear-gradient(180deg, rgba(248, 250, 252, 0.96) 0%, rgba(241, 245, 249, 0.96) 100%);
    border-radius: 20px;
}

.coach-live2d-stage {
    width: 100%;
    height: 100%;
    min-height: 520px;
}

.thinking-panel {
    grid-area: thinking;
    background: rgba(255, 255, 255, 0.72);
    border: 1px solid rgba(228, 228, 231, 0.9);
    box-shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
}

.chat-composer {
    grid-area: composer;
    padding-top: 0;
}

.composer-box {
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(209, 213, 219, 0.9);
    box-shadow: 0 14px 36px rgba(15, 23, 42, 0.08);
}

#chat-input,
.chat-input {
    min-height: 48px;
    font-size: 15px;
    line-height: 1.7;
}

.mode-menu[hidden],
.thinking-panel[hidden] {
    display: none !important;
}

.mode-menu {
    max-width: 320px;
}

.mode-menu-item:hover,
.mode-menu-item[aria-checked="true"] {
    background: var(--bg-hover);
}

.chat-message {
    max-width: min(840px, 100%);
}

.chat-avatar {
    width: 36px;
    height: 36px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid var(--border);
    box-shadow: 0 6px 18px rgba(15, 23, 42, 0.06);
}

.chat-bubble {
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(15, 23, 42, 0.06);
}

.chat-message-user .chat-bubble,
.chat-message.user .chat-bubble {
    background: linear-gradient(180deg, #111827 0%, #0f172a 100%);
}

.chat-meta-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.rendered-content table,
.preformatted table {
    width: 100%;
    border-collapse: collapse;
    margin: 12px 0;
}

.rendered-content th,
.rendered-content td,
.preformatted th,
.preformatted td {
    padding: 10px 12px;
    border: 1px solid var(--border);
    text-align: left;
    vertical-align: top;
}

.rendered-content th,
.preformatted th {
    background: var(--bg-surface);
}

.admin-shell,
.codex-admin-shell {
    grid-template-columns: 272px minmax(0, 1fr);
    gap: 18px;
    padding: 20px;
    min-height: 100vh;
}

.admin-sidebar,
.codex-admin-sidebar,
.admin-main,
.codex-admin-main,
.admin-topbar,
.codex-admin-topbar,
.list-panel,
.form-panel {
    background: rgba(255, 255, 255, 0.82);
    border: 1px solid rgba(228, 228, 231, 0.9);
    box-shadow: 0 24px 60px rgba(15, 23, 42, 0.08);
    backdrop-filter: blur(14px);
}

.admin-sidebar,
.codex-admin-sidebar {
    position: sticky;
    top: 20px;
    height: calc(100vh - 40px);
    border-right: none;
}

.admin-main,
.codex-admin-main {
    min-width: 0;
    padding: 0;
    background: transparent;
    border: none;
    box-shadow: none;
    backdrop-filter: none;
}

.admin-topbar,
.codex-admin-topbar {
    padding: 18px 20px;
}

.status-column {
    align-items: flex-start;
    flex-direction: column;
    gap: 6px;
}

.student-list-item > div:first-child,
.student-list-item > div:last-child {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.student-list-item strong {
    color: #0f172a;
}

.metric-card strong,
.summary-strip strong {
    letter-spacing: -0.03em;
}

.student-admin-grid {
    grid-template-columns: minmax(320px, 420px) minmax(0, 1fr);
}

@media (max-width: 1100px) {
    .auth-codex-shell {
        grid-template-columns: 1fr;
    }

    .chat-stage,
    .codex-chat-stage {
        grid-template-columns: 1fr;
        grid-template-areas:
            "feed"
            "thinking"
            "composer"
            "coach";
    }

    .coach-live2d-stage {
        min-height: 360px;
    }
}

@media (max-width: 720px) {
    .studio-shell,
    .studio-shell.studio-shell-chat-only,
    .admin-shell,
    .codex-admin-shell {
        padding: 12px;
    }

    .main-toolbar.chat-only-toolbar,
    .main-toolbar,
    .codex-toolbar,
    .admin-topbar,
    .codex-admin-topbar {
        padding: 14px 16px;
    }

    .toolbar-actions,
    .composer-actions {
        flex-wrap: wrap;
    }

    .summary-strip,
    .student-summary-grid,
    .student-profile-grid,
    .form-grid-two,
    .student-admin-grid {
        grid-template-columns: 1fr;
    }

    .auth-codex-hero,
    .auth-codex-form-panel {
        padding: 24px;
    }
}

/* 20260406d minimalist login + transparent Live2D stage */
body.auth-page {
    padding: 24px !important;
}

.auth-minimal-shell {
    width: 100%;
    max-width: 360px;
}

.auth-minimal-form {
    display: grid;
    gap: 12px;
    padding: 18px;
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(228, 228, 231, 0.9);
    box-shadow: 0 12px 32px rgba(15, 23, 42, 0.08);
}

.auth-minimal-form input {
    width: 100%;
    min-height: 44px;
    padding: 0 12px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: #fff;
}

.auth-minimal-form .primary-btn {
    min-height: 44px;
    border-radius: 10px;
}

body.student-page .coach-widget,
body.student-page .coach-stage-shell,
body.student-page .coach-live2d-stage {
    background: transparent !important;
    border: 0 !important;
    box-shadow: none !important;
    backdrop-filter: none !important;
}

body.student-page .coach-stage-shell {
    padding: 0 !important;
    border-radius: 0 !important;
}

body.student-page .coach-stage-shell::before,
body.student-page .coach-stage-shell::after {
    display: none !important;
    content: none !important;
}