:root {
    --bg-app: #121212; /* Pitch black background for gaps/margins */
    --bg-panel: #181818; /* Unified Premium Soft Charcoal */
    --bg-header: #1e1e1e; /* VS Code tab/title background */
    --bg-footer: #1e1e1e;
    
    --border-color: #2b2b2b; /* Sleek flat border */
    --border-color-glow: #007acc; /* VS Code active blue highlight */
    
    --accent-blue: #007acc;
    --accent-cyan: #4fc1ff;
    --accent-purple: #c586c0;
    
    --text-primary: #d4d4d4; /* Monaco/VS Code text */
    --text-secondary: #858585; /* VS Code muted text */
    --text-muted: #5a5a5a;
    
    --success: #4ec9b0; /* VS Code class green */
    --warning: #cca700;
    --danger: #f44747;
    --danger-bg: rgba(244, 71, 71, 0.1);
    
    --shadow-sm: none;
    --shadow-md: none;
    --shadow-glow: none;
    
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

/* Blinking terminal cursor animation */
@keyframes blink {
    50% { opacity: 0; }
}
.blink-cursor {
    animation: blink 1.2s step-start infinite;
    display: inline-block;
}

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

body {
    background-color: var(--bg-app);
    color: var(--text-primary);
    font-family: var(--font-sans);
    height: 100vh;
    overflow: hidden;
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}
::-webkit-scrollbar-track {
    background: var(--bg-panel);
}
::-webkit-scrollbar-thumb {
    background: #424242;
    border-radius: 0px;
}
::-webkit-scrollbar-thumb:hover {
    background: #4f4f4f;
}

/* App Main Container */
.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    background-color: var(--bg-app);
}

/* Header styling */
.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.5rem 1rem;
    background-color: var(--bg-header);
    border-bottom: 1px solid var(--border-color);
    z-index: 10;
    height: 48px;
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-text h1 {
    font-size: 1.05rem;
    font-weight: 700;
    color: #ffffff;
    font-family: var(--font-mono);
    letter-spacing: -0.01em;
}

.logo-text span {
    font-size: 0.7rem;
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

.header-status {
    display: flex;
    align-items: center;
    gap: 1.25rem;
}

.status-badge {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.25rem 0.6rem;
    border-radius: 3px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border: 1px solid transparent;
}

.status-badge.connected {
    background: rgba(78, 201, 176, 0.1);
    color: var(--success);
    border-color: rgba(78, 201, 176, 0.2);
}

.status-badge.connecting {
    background: rgba(204, 167, 0, 0.1);
    color: var(--warning);
    border-color: rgba(204, 167, 0, 0.2);
}

.status-badge.disconnected {
    background: rgba(244, 71, 71, 0.1);
    color: var(--danger);
    border-color: rgba(244, 71, 71, 0.2);
}

.status-badge .indicator {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: currentColor;
}

.status-badge.connecting .indicator {
    animation: pulse 1.5s infinite;
}

@keyframes pulse {
    0% { opacity: 0.4; }
    50% { opacity: 1; }
    100% { opacity: 0.4; }
}

.session-info {
    font-size: 0.75rem;
    font-family: var(--font-mono);
    display: flex;
    gap: 0.3rem;
}

.session-info .label {
    color: var(--text-secondary);
}

.session-info .value {
    color: var(--accent-cyan);
}

/* Main Split View */
.app-main {
    display: grid;
    grid-template-columns: 1fr 6px 1fr;
    gap: 0;
    flex: 1;
    padding: 0.5rem;
    height: 60vh;
    min-height: 0; /* Important for grid item content overflow */
}

/* Panes Splitter (Horizontal) */
.panes-splitter {
    width: 6px;
    cursor: col-resize;
    background-color: transparent;
    transition: background-color 0.2s;
    position: relative;
    z-index: 10;
}
.panes-splitter:hover, .panes-splitter.active {
    background-color: var(--accent-blue);
}

/* Vertical Splitter (between main panels and footer) */
.vertical-splitter {
    height: 6px;
    cursor: row-resize;
    background-color: transparent;
    transition: background-color 0.2s;
    position: relative;
    z-index: 10;
}
.vertical-splitter:hover, .vertical-splitter.active {
    background-color: var(--accent-blue);
}

/* Panel Card Structure */
.panel-card {
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 2px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: none;
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.4rem 0.75rem;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-header);
    height: 35px;
}

.panel-title {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    color: var(--text-primary);
}

.panel-title h2 {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.panel-actions {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.panel-body {
    flex: 1;
    min-height: 0;
    overflow: hidden;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.3rem;
    padding: 0.25rem 0.6rem;
    border-radius: 2px;
    font-size: 0.75rem;
    font-weight: 500;
    font-family: var(--font-sans);
    cursor: pointer;
    border: 1px solid var(--border-color);
    background: #3c3c3c;
    color: #ffffff;
    transition: all 0.15s ease;
}

.btn:hover {
    background: #4c4c4c;
    border-color: #5c5c5c;
}

.btn:active {
    transform: scale(0.98);
}

.btn-primary {
    background: #007acc;
    color: #ffffff;
    border: none;
}

.btn-primary:hover {
    background: #0087e0;
    box-shadow: none;
}

.btn-secondary {
    background: #2d2d2d;
    border-color: #3e3e42;
}

.btn-secondary:hover {
    border-color: #5a5a5a;
    color: #ffffff;
}

.btn-icon {
    padding: 0.25rem;
    border-radius: 2px;
    color: #cccccc;
    background: transparent;
    border: none;
}

.btn-icon:hover {
    color: #ffffff;
    background: #333333;
}

.btn-danger-hover:hover {
    color: #ffffff;
    background: var(--danger);
    border-color: var(--danger);
}

/* Monaco Editor Container */
.editor-body {
    display: flex;
    flex-direction: column;
}

#editor-container {
    flex: 1;
    width: 100%;
    height: 100%;
}

/* Terminal container */
.terminal-body {
    background-color: var(--bg-panel); /* matches Monaco background */
    padding: 0.5rem;
}

#terminal-container {
    width: 100%;
    height: 100%;
    font-family: var(--font-mono);
}

/* Xterm overrides to fit layout */
.xterm .xterm-viewport {
    background-color: var(--bg-panel) !important;
}

/* State / Lower section */
.app-footer {
    padding: 0 0.5rem 0.5rem 0.5rem;
    height: 30vh;
    min-height: 0;
    display: flex;
}

.state-card {
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* Tab buttons */
.tabs-header {
    display: flex;
    gap: 0.1rem;
}

.tab-btn {
    background: none;
    border: none;
    padding: 0.4rem 0.8rem;
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: 0px;
    transition: all 0.15s ease;
    border-bottom: 2px solid transparent;
}

.tab-btn:hover {
    color: #ffffff;
    background: rgba(255, 255, 255, 0.05);
}

.tab-btn.active {
    color: #ffffff;
    background: var(--bg-panel);
    border-bottom-color: var(--accent-blue);
}

/* Tab content viewports */
.state-body {
    padding: 0.75rem;
    background-color: var(--bg-panel);
    overflow-y: auto;
    border: 1px solid var(--border-color);
    border-top: none;
    flex: 1;
    min-height: 0;
}

.tab-content {
    display: none;
    height: 100%;
}

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

/* State Tab: Cumulative Code View */
.state-container {
    height: 100%;
    display: flex;
    flex-direction: column;
}

.state-code-wrapper {
    background: var(--bg-panel);
    border: none;
    border-radius: 0;
    padding: 0;
    height: 100%;
    overflow: auto;
}

.code-view {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    line-height: 1.5;
    color: #d4d4d4;
    white-space: pre-wrap;
    word-break: break-all;
}

/* Snippets Tab styling */
.snippets-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.75rem;
    padding: 0.25rem;
}

.snippet-item {
    background: #252526;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 0.75rem;
    cursor: pointer;
    transition: all 0.15s ease;
}

.snippet-item:hover {
    background: #2d2d30;
    border-color: var(--accent-blue);
}

.snippet-item h3 {
    font-size: 0.8rem;
    font-weight: 600;
    color: #ffffff;
    margin-bottom: 0.25rem;
}

.snippet-item p {
    font-size: 0.72rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

/* Help Content styling */
.help-content {
    max-width: 800px;
}

.help-callout {
    margin-top: 1rem;
    padding: 0.75rem 1rem;
    border-radius: 4px;
    font-size: 0.75rem;
    line-height: 1.5;
}

.help-callout.warning {
    background: rgba(204, 167, 0, 0.1);
    border: 1px solid rgba(204, 167, 0, 0.3);
    color: #dcdcaa;
}

.help-content h3 {
    font-size: 0.85rem;
    color: var(--accent-cyan);
    margin-bottom: 0.5rem;
}

.help-content ul {
    list-style-position: inside;
    margin-left: 0.5rem;
}

.help-content li {
    font-size: 0.75rem;
    color: var(--text-primary);
    line-height: 1.6;
    margin-bottom: 0.4rem;
}

.help-content code {
    font-family: var(--font-mono);
    background: #2d2d30;
    padding: 0.1rem 0.3rem;
    border-radius: 3px;
    color: #ce9178;
}

/* Responsiveness adjustments */
@media (max-height: 700px) {
    .app-main {
        height: 55vh;
    }
    .app-footer {
        height: 35vh;
    }
}