/* TAKA Link AI Agent Learning Platform - Clean SaaS Stylesheet (Dark Modern Slate & Indigo) */

:root {
    /* Color Palette - Dark Modern Slate (#0F172A) / Indigo (#3B82F6) Clean SaaS */
    --bg-primary: #0f172a;       /* Slate 900: Primary Background */
    --bg-secondary: #020617;     /* Slate 950: Header / Footer / Deep Background */
    --bg-panel: #1e293b;         /* Slate 800: Panel / Container Background */
    --bg-card: #1e293b;          /* Slate 800: Card Background */
    --bg-card-hover: #334155;    /* Slate 700: Card Hover Background */
    --bg-input: #0f172a;         /* Slate 900: Form Input Background */
    --bg-header: #0b1120;        /* Slate 950: Top Bar Header */

    /* Text Colors */
    --text-primary: #f8fafc;     /* Slate 50: High-contrast Main Text */
    --text-secondary: #94a3b8;   /* Slate 400: Subordinate / Label Text */
    --text-muted: #64748b;       /* Slate 500: Annotations / Inactive Text */

    /* Accent Colors (Indigo Clean SaaS Core) */
    --accent-blue: #3b82f6;               /* Legacy alias for Indigo 500 */
    --accent-indigo-primary: #3b82f6;     /* Indigo 500: Primary Action / Highlights */
    --accent-indigo-hover: #2563eb;       /* Indigo 600: Primary Button Hover */
    --accent-indigo-active: #1d4ed8;      /* Indigo 700: Button Active */
    --accent-indigo-light: #60a5fa;       /* Blue 400: Sub-accent / Links */
    --accent-indigo-glow: rgba(59, 130, 246, 0.25); /* Glow Effect */

    /* Status & Feedback Colors */
    --accent-green: #10b981;     /* Emerald 500: Success / OK */
    --accent-amber: #f59e0b;     /* Amber 500: Warning / Processing */
    --accent-rose: #f43f5e;      /* Rose 500: Error / Failure */

    --status-success: #10b981;   /* Emerald 500 */
    --status-warning: #f59e0b;   /* Amber 500 */
    --status-error: #f43f5e;     /* Rose 500 */
    --status-info: #38bdf8;      /* Sky 400 */

    /* Borders & Dividers */
    --border-color: #334155;       /* Slate 700: Standard Border */
    --border-color-focus: #3b82f6; /* Indigo 500: Focus Border */

    /* Typography */
    --font-sans: 'Inter', 'Hiragino Sans', 'Yu Gothic UI', 'Meiryo', 'Noto Sans JP', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', 'Courier New', monospace;

    /* Shadows & Border Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --shadow-card: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 20px rgba(59, 130, 246, 0.2);
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

body.resizing-h {
    cursor: col-resize;
    user-select: none;
}

body.resizing-v {
    cursor: row-resize;
    user-select: none;
}

/* ==========================================
   Navigation & Header
   ========================================== */

.mobile-tab-bar {
    display: none;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 0.5rem 1rem;
    gap: 0.5rem;
    justify-content: space-around;
    position: sticky;
    top: 0;
    z-index: 100;
}

.mobile-tab-btn {
    flex: 1;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border-color);
    background-color: var(--bg-card);
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s ease;
}

.mobile-tab-btn.active {
    background-color: var(--accent-indigo-primary);
    color: #ffffff;
    border-color: var(--accent-indigo-primary);
}

.app-header {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 0.8rem 1.5rem;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1800px;
    margin: 0 auto;
    width: 100%;
}

.app-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent-indigo-light);
    letter-spacing: -0.025em;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.control-group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.select-input {
    background-color: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 0.35rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    outline: none;
    transition: border-color 0.2s;
}

.select-input:focus {
    border-color: var(--accent-indigo-primary);
    box-shadow: 0 0 0 2px var(--accent-indigo-glow);
}

/* ==========================================
   Status Badges
   ========================================== */

.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.6rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.badge-checking {
    background-color: #334155;
    color: #cbd5e1;
}

.badge-ok,
.badge-emerald {
    background-color: rgba(16, 185, 129, 0.15);
    color: #34d399;
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.badge-error,
.badge-rose {
    background-color: rgba(244, 63, 94, 0.15);
    color: #f87171;
    border: 1px solid rgba(244, 63, 94, 0.3);
}

.badge-amber {
    background-color: rgba(245, 158, 11, 0.15);
    color: #fbbf24;
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.badge-indigo {
    background-color: rgba(59, 130, 246, 0.15);
    color: #60a5fa;
    border: 1px solid rgba(59, 130, 246, 0.3);
}

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

.progress-bar-container {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    width: 100%;
}

.progress-label {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.progress-bar-track,
.progress-track {
    height: 8px;
    background-color: var(--bg-secondary);
    border-radius: 9999px;
    overflow: hidden;
    position: relative;
    border: 1px solid var(--border-color);
}

.progress-bar-fill,
.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #3b82f6, #60a5fa);
    border-radius: 9999px;
    transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ==========================================
   3-Pane Integrated Main Layout
   ========================================== */

.main-container {
    display: flex;
    flex-direction: row;
    padding: 0.75rem;
    flex: 1;
    max-width: 100vw;
    height: calc(100vh - 70px);
    overflow: hidden;
    margin: 0 auto;
    width: 100%;
    box-sizing: border-box;
}

/* Pane 1 (Left: Video/Curriculum/Diagram) */
#video-panel {
    flex: 0 0 calc(45% - 4px);
    min-width: 280px;
}

/* Right Column Container (Pane 2 & Pane 3) */
.right-column-container {
    display: flex;
    flex-direction: column;
    flex: 0 0 calc(55% - 4px);
    height: 100%;
    min-width: 280px;
    overflow: hidden;
}

#agent-container,
#paiza-panel {
    flex: 0 0 calc(55% - 4px);
    min-height: 200px;
}

#tutor-panel {
    flex: 0 0 calc(45% - 4px);
    min-height: 200px;
}

/* Splitters / Resizers */
.splitter {
    background-color: var(--border-color);
    position: relative;
    z-index: 10;
    transition: background-color 0.2s ease;
    user-select: none;
    flex-shrink: 0;
}

.splitter:hover,
body.resizing-h #splitter-horizontal,
body.resizing-v #splitter-vertical {
    background-color: var(--accent-indigo-primary);
    box-shadow: var(--shadow-glow);
}

.splitter-h {
    width: 8px;
    cursor: col-resize;
    margin: 0 2px;
    border-radius: 4px;
}

.splitter-v {
    height: 8px;
    cursor: row-resize;
    margin: 2px 0;
    border-radius: 4px;
}

/* Panels */
.column-panel {
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: var(--shadow-card);
}

.panel-header {
    background-color: rgba(15, 23, 42, 0.7);
    padding: 0.75rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.panel-header h2 {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.panel-subtitle {
    font-size: 0.78rem;
    color: var(--text-secondary);
}

.panel-body {
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    flex: 1;
    overflow-y: auto;
}

/* ==========================================
   Video / Curriculum / Diagram Containers
   ========================================== */

.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 Ratio */
    height: 0;
    overflow: hidden;
    border-radius: var(--radius-sm);
    background-color: #000;
    border: 1px solid var(--border-color);
    flex-shrink: 0;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.speed-controls {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.85rem;
}

.speed-controls .control-label {
    color: var(--text-secondary);
    font-weight: 500;
}

.speed-btn {
    background-color: var(--bg-card);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    padding: 0.25rem 0.6rem;
    border-radius: 4px;
    font-size: 0.8rem;
    cursor: pointer;
    transition: all 0.2s;
}

.speed-btn:hover,
.speed-btn.active {
    background-color: var(--accent-indigo-primary);
    color: #ffffff;
    border-color: var(--accent-indigo-primary);
}

/* Subtabs Header Navigation */
.subtabs-nav {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    gap: 0.25rem;
    margin-top: 0.25rem;
}

.subtab-btn {
    padding: 0.4rem 0.8rem;
    background: transparent;
    border: none;
    border-bottom: 2px solid transparent;
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.subtab-btn:hover {
    color: var(--text-primary);
}

.subtab-btn.active {
    color: var(--accent-indigo-light);
    border-bottom-color: var(--accent-indigo-primary);
}

.subtabs-content {
    padding: 0.5rem 0;
    font-size: 0.9rem;
}

.subtab-pane {
    line-height: 1.6;
}

.subtab-pane pre {
    background-color: var(--bg-secondary);
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    margin-top: 0.5rem;
    font-family: var(--font-mono);
    border: 1px solid var(--border-color);
}

.chapter-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.chapter-list li {
    padding: 0.4rem 0.6rem;
    background-color: var(--bg-card);
    border-radius: 4px;
    font-size: 0.85rem;
    border: 1px solid var(--border-color);
}

.chapter-time,
.time-tag {
    color: var(--accent-indigo-light);
    font-weight: 600;
    font-family: var(--font-mono);
    margin-right: 0.5rem;
}

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

/* ==========================================
   Forms, Inputs, and Editors
   ========================================== */

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.form-group label,
.form-label {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.text-input,
.input-field {
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.6rem 0.8rem;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-family: var(--font-sans);
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.code-textarea,
.chat-textarea,
.monaco-editor-container {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: #e2e8f0;
    font-family: var(--font-mono);
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    line-height: 1.5;
    resize: vertical;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.code-textarea:focus,
.text-input:focus,
.chat-textarea:focus,
.input-field:focus {
    border-color: var(--accent-indigo-primary);
    box-shadow: 0 0 0 2px var(--accent-indigo-glow);
}

.editor-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    cursor: pointer;
    color: var(--text-primary);
    font-size: 0.875rem;
}

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

.action-bar,
.chat-action-bar {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    padding: 0.55rem 1.1rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    border: none;
    transition: all 0.2s ease;
    text-decoration: none;
    line-height: 1.2;
}

.btn-primary {
    background-color: var(--accent-indigo-primary);
    color: #ffffff;
}

.btn-primary:hover {
    background-color: var(--accent-indigo-hover);
    box-shadow: var(--shadow-glow);
}

.btn-primary:active {
    background-color: var(--accent-indigo-active);
}

.btn-secondary {
    background-color: #334155;
    color: #f8fafc;
}

.btn-secondary:hover {
    background-color: #475569;
}

.btn-success {
    background-color: var(--status-success);
    color: #ffffff;
}

.btn-success:hover {
    background-color: #059669;
}

.btn-warning {
    background-color: var(--status-warning);
    color: #ffffff;
}

.btn-warning:hover {
    background-color: #d97706;
}

.btn-danger {
    background-color: var(--status-error);
    color: #ffffff;
}

.btn-danger:hover {
    background-color: #e11d48;
}

.btn-info {
    background-color: var(--status-info);
    color: #ffffff;
}

.btn-info:hover {
    background-color: #0284c7;
}

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

.btn-ghost:hover {
    color: var(--text-primary);
    border-color: var(--accent-indigo-primary);
    background-color: rgba(59, 130, 246, 0.1);
}

.btn-sm {
    padding: 0.35rem 0.75rem;
    font-size: 0.8rem;
}

.btn-lg {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
}

.btn-full {
    width: 100%;
}


/* ==========================================
   Console & //loop Panels
   ========================================== */

.console-box {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.console-header {
    background-color: var(--bg-primary);
    padding: 0.4rem 0.8rem;
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.time-label {
    color: var(--accent-indigo-light);
    font-family: var(--font-mono);
}

.console-content {
    padding: 0.75rem;
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: #4ade80;
    white-space: pre-wrap;
    max-height: 150px;
    overflow-y: auto;
}

.loop-panel {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.8rem;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.loop-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.loop-header h3 {
    font-size: 0.9rem;
    color: var(--accent-indigo-light);
}

.reflection-container {
    font-size: 0.85rem;
    line-height: 1.4;
    color: #cbd5e1;
}

.reflection-card {
    background-color: var(--bg-card);
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    border-left: 4px solid var(--accent-amber);
    margin-top: 0.5rem;
}

.reflection-card .title {
    font-weight: 600;
    color: #fde047;
    margin-bottom: 0.3rem;
}

/* ==========================================
   AI Tutor Chat Panel
   ========================================== */

.chat-history {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.8rem;
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    min-height: 150px;
    max-height: 220px;
    overflow-y: auto;
}

.chat-message {
    padding: 0.75rem;
    border-radius: 8px;
    max-width: 90%;
    font-size: 0.9rem;
    line-height: 1.4;
}

.message-system {
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    align-self: flex-start;
}

.message-user {
    background-color: var(--accent-indigo-primary);
    color: #ffffff;
    align-self: flex-end;
}

.message-tutor {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-left: 3px solid var(--accent-indigo-primary);
    align-self: flex-start;
}

.message-sender {
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--accent-indigo-light);
}

.message-user .message-sender {
    color: #bae6fd;
}

/* Quiz & Citation Panels */
.quiz-panel {
    background-color: #3b0764;
    border: 1px solid #7e22ce;
    border-radius: var(--radius-sm);
    padding: 0.8rem;
}

.quiz-header h3 {
    font-size: 0.9rem;
    color: #e9d5ff;
}

.quiz-question-text {
    font-weight: 600;
    margin-top: 0.4rem;
    color: #f3e8ff;
}

.quiz-hint-text {
    font-size: 0.8rem;
    color: #d8b4fe;
    margin-top: 0.3rem;
    font-style: italic;
}

.citation-panel {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.8rem;
}

.citation-panel h3 {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.4rem;
}

.citation-item {
    background-color: var(--bg-card);
    padding: 0.5rem 0.75rem;
    border-radius: 4px;
    font-size: 0.8rem;
    margin-bottom: 0.4rem;
    border-left: 3px solid var(--accent-indigo-primary);
}

.citation-source {
    font-weight: 600;
    color: var(--accent-indigo-light);
    margin-bottom: 0.2rem;
}

.placeholder-text {
    color: var(--text-secondary);
    font-style: italic;
    font-size: 0.85rem;
}

.hidden {
    display: none !important;
}

/* ==========================================
   Login Screen UI Components (Milestone 2)
   ========================================== */

.login-card {
    max-width: 420px;
    width: 100%;
    margin: auto;
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.4);
}

.login-header {
    text-align: center;
    margin-bottom: 1.5rem;
}

.login-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.login-header p {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

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

.alert-box {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    margin-bottom: 1.25rem;
    border: 1px solid transparent;
}

.alert-box.alert-error {
    background-color: rgba(244, 63, 94, 0.15);
    border-color: var(--status-error);
    color: #fca5a5;
}

.alert-box.alert-success {
    background-color: rgba(16, 185, 129, 0.15);
    border-color: var(--status-success);
    color: #6ee7b7;
}

.alert-box.alert-info {
    background-color: rgba(56, 189, 248, 0.15);
    border-color: var(--status-info);
    color: #7dd3fc;
}

.preset-container {
    margin-top: 1.5rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.preset-label {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    text-align: center;
}

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

.preset-btn {
    width: 100%;
    justify-content: center;
    font-size: 0.85rem;
    padding: 0.5rem;
}

/* ==========================================
   Course List Dashboard UI (Milestone 3)
   ========================================== */

.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
    padding: 1.5rem 0;
}

.course-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
    display: flex;
    flex-direction: column;
}

.course-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-indigo-primary);
    box-shadow: var(--shadow-glow);
}

.course-card-thumb {
    position: relative;
    aspect-ratio: 16 / 9;
    background-color: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    border-bottom: 1px solid var(--border-color);
}

.course-chapter-badge {
    position: absolute;
    top: 0.75rem;
    left: 0.75rem;
}

.course-card-body {
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    flex: 1;
}

.course-card-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
}

.instructor-info {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ==========================================
   Footer
   ========================================== */

.app-footer {
    text-align: center;
    padding: 0.6rem;
    font-size: 0.8rem;
    color: var(--text-secondary);
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
    flex-shrink: 0;
}

/* ==========================================
   Responsive Fallback @media (max-width: 1024px)
   ========================================== */

@media (max-width: 1024px) {
    .mobile-tab-bar {
        display: flex;
    }

    .main-container {
        flex-direction: column;
        height: auto;
        overflow: visible;
        padding: 0.5rem;
    }

    .splitter {
        display: none !important;
    }

    .right-column-container {
        display: flex;
        flex-direction: column;
        width: 100% !important;
        height: auto !important;
    }

    .column-panel.pane {
        width: 100% !important;
        height: auto !important;
        display: none;
    }

    .column-panel.pane.mobile-active {
        display: flex !important;
    }
}

/* ==========================================
   AI Agent Chat UI Components (Dark Indigo SaaS Theme)
   ========================================== */

/* ------------------------------------------
   a) Chat Container & Scrollable History
   ------------------------------------------ */
#agent-chat-history,
.agent-chat-history,
#agent-container,
#agent-chat-container,
#chat-history,
.chat-history {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
    min-height: 200px;
    max-height: 520px;
    overflow-y: auto;
    scroll-behavior: smooth;
}

/* Webkit Scrollbar Customization */
#agent-chat-history::-webkit-scrollbar,
.agent-chat-history::-webkit-scrollbar,
#agent-container::-webkit-scrollbar,
#agent-chat-container::-webkit-scrollbar,
#chat-history::-webkit-scrollbar,
.chat-history::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

#agent-chat-history::-webkit-scrollbar-track,
.agent-chat-history::-webkit-scrollbar-track,
#agent-container::-webkit-scrollbar-track,
#agent-chat-container::-webkit-scrollbar-track,
#chat-history::-webkit-scrollbar-track,
.chat-history::-webkit-scrollbar-track {
    background: var(--bg-secondary);
    border-radius: 4px;
}

#agent-chat-history::-webkit-scrollbar-thumb,
.agent-chat-history::-webkit-scrollbar-thumb,
#agent-container::-webkit-scrollbar-thumb,
#agent-chat-container::-webkit-scrollbar-thumb,
#chat-history::-webkit-scrollbar-thumb,
.chat-history::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

#agent-chat-history::-webkit-scrollbar-thumb:hover,
.agent-chat-history::-webkit-scrollbar-thumb:hover,
#agent-container::-webkit-scrollbar-thumb:hover,
#agent-chat-container::-webkit-scrollbar-thumb:hover,
#chat-history::-webkit-scrollbar-thumb:hover,
.chat-history::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ------------------------------------------
   b) User Message Bubbles
   ------------------------------------------ */
.chat-message.message-user,
.message-user-bubble,
.user-message-bubble,
.message-user {
    align-self: flex-end;
    margin-left: auto;
    margin-right: 0;
    max-width: 85%;
    padding: 0.75rem 1rem;
    background: linear-gradient(135deg, #3b82f6 0%, #2563eb 100%);
    color: #ffffff;
    border-radius: 16px 16px 4px 16px;
    box-shadow: 0 2px 8px rgba(59, 130, 246, 0.25);
    font-size: 0.9rem;
    line-height: 1.5;
    word-break: break-word;
}

/* ------------------------------------------
   c) Agent Message Bubbles & Avatars
   ------------------------------------------ */
.chat-message.message-agent,
.message-agent-bubble,
.agent-message-bubble,
.message-tutor,
.message-agent {
    align-self: flex-start;
    margin-left: 0;
    margin-right: auto;
    max-width: 85%;
    padding: 0.75rem 1rem;
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-left: 3px solid var(--accent-indigo-primary);
    color: var(--text-primary);
    border-radius: 16px 16px 16px 4px;
    box-shadow: var(--shadow-card);
    font-size: 0.9rem;
    line-height: 1.5;
    word-break: break-word;
}

.message-sender,
.agent-avatar {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.35rem;
    color: var(--accent-indigo-light);
    letter-spacing: 0.02em;
}

.agent-avatar img,
.agent-avatar svg,
.message-sender img,
.message-sender svg {
    width: 18px;
    height: 18px;
    border-radius: 50%;
}

.message-user .message-sender,
.message-user-bubble .message-sender,
.user-message-bubble .message-sender {
    color: #bae6fd;
    justify-content: flex-end;
}

/* ------------------------------------------
   d) System Log & Internal Thinking Entries
   ------------------------------------------ */
.system-log-entry,
.thinking-log,
.tool-execution-log,
.agent-internal-log,
.agent-step-log,
.message-system {
    align-self: stretch;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    background-color: rgba(15, 23, 42, 0.8);
    border: 1px dashed var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.6rem 0.85rem;
    color: var(--text-secondary);
    line-height: 1.4;
    position: relative;
}

/* Status pill badges for logs */
.log-pill,
.status-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.15rem 0.5rem;
    border-radius: 9999px;
    font-size: 0.72rem;
    font-weight: 600;
    font-family: var(--font-mono);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin-right: 0.4rem;
    background-color: rgba(59, 130, 246, 0.15);
    color: var(--accent-indigo-light);
    border: 1px solid rgba(59, 130, 246, 0.3);
}

.status-pill.status-planning,
.log-pill.log-planning {
    background-color: rgba(168, 85, 247, 0.15);
    color: #c084fc;
    border-color: rgba(168, 85, 247, 0.3);
}

.status-pill.status-tool,
.log-pill.log-tool {
    background-color: rgba(245, 158, 11, 0.15);
    color: #fbbf24;
    border-color: rgba(245, 158, 11, 0.3);
}

.status-pill.status-observation,
.log-pill.log-observation {
    background-color: rgba(56, 189, 248, 0.15);
    color: #38bdf8;
    border-color: rgba(56, 189, 248, 0.3);
}

.status-pill.status-correction,
.log-pill.log-correction {
    background-color: rgba(244, 63, 94, 0.15);
    color: #fb7185;
    border-color: rgba(244, 63, 94, 0.3);
}

/* Active Thinking Glowing Pulse Indicator */
.thinking-log.active::before,
.agent-internal-log.thinking::before,
.thinking-indicator {
    content: '';
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--accent-indigo-primary);
    margin-right: 0.5rem;
    animation: pulse-glow 1.5s infinite ease-in-out;
}

@keyframes pulse-glow {
    0% {
        transform: scale(0.95);
        box-shadow: 0 0 0 0 rgba(59, 130, 246, 0.7);
    }
    70% {
        transform: scale(1.1);
        box-shadow: 0 0 0 8px rgba(59, 130, 246, 0);
    }
    100% {
        transform: scale(0.95);
        box-shadow: 0 0 0 0 rgba(59, 130, 246, 0);
    }
}

/* ------------------------------------------
   e) Input Form & Action Controls
   ------------------------------------------ */
.agent-chat-input-container,
.chat-input-wrapper {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.75rem;
    margin-top: 0.5rem;
    box-shadow: var(--shadow-card);
}

.agent-chat-input-container .input-row,
.chat-input-wrapper .input-row {
    display: flex;
    gap: 0.5rem;
    align-items: flex-end;
}

#agent-chat-input,
#question-input,
.agent-chat-input-container textarea,
.chat-input-wrapper textarea {
    flex: 1;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.9rem;
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    resize: vertical;
    min-height: 50px;
    max-height: 160px;
    outline: none;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

#agent-chat-input:focus,
#question-input:focus,
.agent-chat-input-container textarea:focus,
.chat-input-wrapper textarea:focus {
    border-color: var(--accent-indigo-primary);
    box-shadow: 0 0 0 3px var(--accent-indigo-glow);
}

#agent-send-btn,
#btn-ask,
.btn-send {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    padding: 0.65rem 1.25rem;
    background: linear-gradient(135deg, var(--accent-indigo-primary) 0%, var(--accent-indigo-hover) 100%);
    color: #ffffff;
    font-weight: 600;
    font-size: 0.875rem;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

#agent-send-btn:hover,
#btn-ask:hover,
.btn-send:hover {
    background: linear-gradient(135deg, #60a5fa 0%, var(--accent-indigo-primary) 100%);
    box-shadow: var(--shadow-glow);
    transform: translateY(-1px);
}

#agent-send-btn:active,
#btn-ask:active,
.btn-send:active {
    background-color: var(--accent-indigo-active);
    transform: translateY(0);
}

#agent-send-btn:disabled,
#btn-ask:disabled,
.btn-send:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* ------------------------------------------
   f) Responsive Design Adjustments
   ------------------------------------------ */
@media (max-width: 768px) {
    #agent-chat-history,
    .agent-chat-history,
    #agent-container,
    #agent-chat-container,
    #chat-history,
    .chat-history {
        max-height: 380px;
        padding: 0.75rem;
        gap: 0.65rem;
    }

    .chat-message.message-user,
    .message-user-bubble,
    .user-message-bubble,
    .message-user,
    .chat-message.message-agent,
    .message-agent-bubble,
    .agent-message-bubble,
    .message-tutor,
    .message-agent {
        max-width: 92%;
        padding: 0.65rem 0.85rem;
        font-size: 0.85rem;
    }

    .system-log-entry,
    .thinking-log,
    .tool-execution-log,
    .agent-internal-log,
    .agent-step-log,
    .message-system {
        font-size: 0.75rem;
        padding: 0.5rem 0.65rem;
    }

    .agent-chat-input-container,
    .chat-input-wrapper {
        padding: 0.6rem;
    }

    #agent-send-btn,
    #btn-ask,
    .btn-send {
        padding: 0.6rem 1rem;
        font-size: 0.825rem;
    }
}