:root {
    --bg-primary: #1e1e1e;
    --bg-secondary: #252526;
    --bg-tertiary: #2d2d30;
    --bg-hover: #3c3c3c;
    --text-primary: #d4d4d4;
    --text-secondary: #808080;
    --text-muted: #6a6a6a;
    --accent: #569cd6;
    --accent-hover: #6eb3e8;
    --success: #4ec9b0;
    --error: #f14c4c;
    --warning: #cca700;
    --border: #3c3c3c;
    --divider: #007acc;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Header */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

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

header h1 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.version {
    font-size: 0.75rem;
    color: var(--text-secondary);
    background: var(--bg-tertiary);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
}

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

select {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border);
    padding: 0.5rem 0.75rem;
    border-radius: 4px;
    font-size: 0.875rem;
    cursor: pointer;
}

select:hover {
    border-color: var(--accent);
}

.btn-primary {
    background: var(--accent);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    font-size: 0.875rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: background 0.2s;
}

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

.btn-primary.compiled {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: default;
    opacity: 0.55;
}

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

@keyframes btn-ready {
    0%   { box-shadow: 0 0 0 0 rgba(86, 156, 214, 0.7); }
    70%  { box-shadow: 0 0 0 7px rgba(86, 156, 214, 0); }
    100% { box-shadow: 0 0 0 0 rgba(86, 156, 214, 0); }
}

.btn-primary.needs-compile {
    animation: btn-ready 0.5s ease;
}

.btn-icon {
    background: transparent;
    color: var(--text-secondary);
    border: none;
    padding: 0.5rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: color 0.2s, background 0.2s;
}

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

/* Main Content */
main {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* Sidebar / File Explorer */
.sidebar {
    width: 220px;
    min-width: 150px;
    max-width: 400px;
    background: var(--bg-secondary);
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--border);
    flex-shrink: 0;
}

.sidebar-header {
    display: flex;
    align-items: center;
    padding: 0.5rem 0.75rem;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
}

.sidebar-header i {
    margin-right: 0.5rem;
}

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

.sidebar-action-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.25rem 0.375rem;
    border-radius: 3px;
    font-size: 0.75rem;
    transition: color 0.15s, background 0.15s;
    display: flex;
    align-items: center;
}

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

.file-tree {
    flex: 1;
    overflow-y: auto;
    padding: 0.5rem 0;
}

.tree-section {
    margin-bottom: 0.5rem;
}

.tree-section-header {
    display: flex;
    align-items: center;
    padding: 0.375rem 0.75rem;
    font-size: 0.6875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    user-select: none;
}

.tree-item {
    display: flex;
    align-items: center;
    padding: 0.375rem 0.75rem;
    padding-left: 1rem;
    font-size: 0.8125rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
    user-select: none;
}

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

.tree-item.active {
    background: var(--bg-hover);
    color: var(--accent);
}

.tree-item i {
    margin-right: 0.5rem;
    font-size: 0.75rem;
    width: 1rem;
    text-align: center;
}

.tree-item .fa-file-code {
    color: var(--success);
}

.tree-folder {
    display: flex;
    align-items: center;
    padding: 0.375rem 0.75rem;
    font-size: 0.8125rem;
    color: var(--text-primary);
    cursor: pointer;
    transition: background 0.15s;
    user-select: none;
    font-weight: 500;
}

.tree-folder:hover {
    background: var(--bg-hover);
}

.tree-folder i {
    margin-right: 0.5rem;
    font-size: 0.75rem;
    width: 1rem;
    text-align: center;
    color: var(--warning);
}

.tree-folder .fa-chevron-down,
.tree-folder .fa-chevron-right {
    color: var(--text-muted);
    font-size: 0.625rem;
    margin-right: 0.375rem;
}

.tree-folder-content {
    display: none;
}

.tree-folder-content.expanded {
    display: block;
}

.tree-folder-content .tree-item {
    padding-left: 2rem;
}

.sidebar-divider {
    width: 4px;
    background: var(--border);
    cursor: col-resize;
    transition: background 0.2s;
    flex-shrink: 0;
}

.sidebar-divider:hover,
.sidebar-divider.dragging {
    background: var(--divider);
}

/* File Tabs */
.file-tabs {
    display: flex;
    gap: 0;
    overflow-x: auto;
    max-width: calc(100% - 150px);
}

.file-tab {
    display: flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.375rem 0.75rem;
    font-size: 0.8125rem;
    color: var(--text-secondary);
    background: transparent;
    border: none;
    border-right: 1px solid var(--border);
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
    white-space: nowrap;
}

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

.file-tab.active {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-bottom: 2px solid var(--accent);
}

.file-tab i {
    font-size: 0.75rem;
    color: var(--success);
}

.file-tab .tab-close {
    margin-left: 0.375rem;
    font-size: 0.625rem;
    color: var(--text-muted);
    opacity: 0;
    transition: opacity 0.15s;
}

.file-tab:hover .tab-close {
    opacity: 1;
}

.file-tab .tab-close:hover {
    color: var(--error);
}

.panel {
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.editor-panel {
    flex: 1;
    min-width: 300px;
}

.output-panel {
    flex: 1;
    min-width: 300px;
    background: var(--bg-secondary);
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 1rem;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--border);
    font-size: 0.875rem;
    flex-shrink: 0;
}

.panel-header span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.file-name {
    color: var(--text-secondary);
}

#editor {
    flex: 1;
    overflow: hidden;
}

/* Divider */
.divider {
    width: 4px;
    background: var(--border);
    cursor: col-resize;
    transition: background 0.2s;
    flex-shrink: 0;
}

.divider:hover,
.divider.dragging {
    background: var(--divider);
}

/* Output Tabs */
.output-tabs {
    display: flex;
    gap: 0.25rem;
}

.tab {
    background: transparent;
    color: var(--text-secondary);
    border: none;
    padding: 0.5rem 0.75rem;
    font-size: 0.8125rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.375rem;
    border-radius: 4px;
    transition: color 0.2s, background 0.2s;
}

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

.tab.active {
    color: var(--text-primary);
    background: var(--bg-secondary);
}

.error-count {
    background: var(--error);
    color: white;
    font-size: 0.6875rem;
    padding: 0.125rem 0.375rem;
    border-radius: 999px;
    min-width: 1.25rem;
    text-align: center;
    display: none;
}

.error-count.visible {
    display: inline;
}

.compile-status {
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    display: none;
    align-items: center;
    gap: 0.25rem;
}

.compile-status.success {
    display: inline-flex;
    color: #4ec9b0;
}

.compile-status.error {
    display: inline-flex;
    color: var(--error);
}

/* Output Content */
.output-content {
    flex: 1;
    overflow: auto;
    position: relative;
}

.output-tab {
    display: none;
    height: 100%;
    overflow: auto;
    padding: 1rem;
    font-family: 'Fira Code', 'Consolas', monospace;
    font-size: 0.8125rem;
    line-height: 1.5;
}

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

#json-output {
    white-space: pre-wrap;
    word-break: break-word;
}

#asm-output {
    white-space: pre-wrap;
}

#errors-output {
    color: var(--error);
}

/* Bindings output */
#bindings-output {
    display: none;
    height: 100%;
    flex-direction: column;
    padding: 0;
}

#bindings-output.active {
    display: flex;
}

.bindings-toolbar {
    display: flex;
    gap: 0;
    padding: 0.5rem 1rem;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
}

.bindings-lang-btn {
    padding: 0.35rem 0.75rem;
    font-size: 0.75rem;
    font-family: inherit;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.15s;
}

.bindings-lang-btn:first-child {
    border-radius: 4px 0 0 4px;
}

.bindings-lang-btn:last-child {
    border-radius: 0 4px 4px 0;
    border-left: none;
}

.bindings-lang-btn.active {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

.bindings-lang-btn:hover:not(.active) {
    background: var(--bg-secondary);
}

.bindings-code {
    flex: 1;
    overflow: auto;
    padding: 1rem;
    font-family: 'Fira Code', 'Consolas', monospace;
    font-size: 0.8125rem;
    line-height: 1.5;
    white-space: pre-wrap;
    word-break: break-word;
}

/* JSON Syntax Highlighting */
.json-key {
    color: #9cdcfe;
}

.json-string {
    color: #ce9178;
}

.json-number {
    color: #b5cea8;
}

.json-boolean {
    color: #569cd6;
}

.json-null {
    color: #569cd6;
}

/* ASM Syntax Highlighting */
.asm-opcode {
    color: #c586c0;
    font-weight: 600;
}

.asm-placeholder {
    color: #4ec9b0;
}

.asm-comment {
    color: #6a9955;
}

.asm-function {
    color: #dcdcaa;
    font-weight: 600;
    display: block;
    margin-top: 1rem;
    margin-bottom: 0.5rem;
    padding-bottom: 0.25rem;
    border-bottom: 1px solid var(--border);
}

.asm-variant {
    color: var(--text-secondary);
    font-style: italic;
    margin-left: 1rem;
}

/* Footer */
footer {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem 1rem;
    background: var(--accent);
    color: white;
    font-size: 0.75rem;
    flex-shrink: 0;
}

.separator {
    opacity: 0.5;
}

kbd {
    background: rgba(255, 255, 255, 0.2);
    padding: 0.125rem 0.375rem;
    border-radius: 3px;
    font-family: inherit;
    font-size: 0.6875rem;
}

/* Loading State */
.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: var(--text-secondary);
}

.loading::after {
    content: '';
    width: 1.5rem;
    height: 1.5rem;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-left: 0.75rem;
}

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

/* Success/Error States */
.compile-success {
    color: var(--success);
}

.compile-error {
    color: var(--error);
}

/* Context Menu */
.context-menu {
    display: none;
    position: fixed;
    z-index: 1000;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 0.25rem 0;
    min-width: 160px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

.context-menu.visible {
    display: block;
}

.context-menu-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.375rem 0.75rem;
    font-size: 0.8125rem;
    color: var(--text-primary);
    cursor: pointer;
    transition: background 0.1s;
}

.context-menu-item:hover {
    background: var(--accent);
    color: white;
}

.context-menu-item i {
    width: 1rem;
    text-align: center;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.context-menu-item:hover i {
    color: white;
}

.context-menu-item.danger {
    color: var(--error);
}

.context-menu-item.danger i {
    color: var(--error);
}

.context-menu-item.danger:hover {
    background: var(--error);
    color: white;
}

.context-menu-item.danger:hover i {
    color: white;
}

.context-menu-separator {
    height: 1px;
    background: var(--border);
    margin: 0.25rem 0;
}

/* Inline Rename Input */
.tree-rename-input {
    background: var(--bg-primary);
    color: var(--text-primary);
    border: 1px solid var(--accent);
    outline: none;
    font-size: 0.8125rem;
    font-family: inherit;
    padding: 0.125rem 0.25rem;
    border-radius: 2px;
    width: calc(100% - 2rem);
    margin-left: 0.25rem;
}

/* New item input row in file tree */
.tree-new-item {
    display: flex;
    align-items: center;
    padding: 0.375rem 0.75rem;
    padding-left: 2rem;
}

.tree-new-item.root-level {
    padding-left: 0.75rem;
}

.tree-new-item input {
    background: var(--bg-primary);
    color: var(--text-primary);
    border: 1px solid var(--accent);
    outline: none;
    font-size: 0.8125rem;
    font-family: inherit;
    padding: 0.125rem 0.25rem;
    border-radius: 2px;
    width: 100%;
    margin-left: 0.25rem;
}

.tree-new-item i {
    font-size: 0.75rem;
    width: 1rem;
    text-align: center;
}

/* Responsive */
@media (max-width: 768px) {
    main {
        flex-direction: column;
    }

    .divider {
        width: 100%;
        height: 4px;
        cursor: row-resize;
    }

    .editor-panel,
    .output-panel {
        min-height: 200px;
    }
}

/* ── Nested sub-folders (projects inside Examples) ──────────────── */

.tree-folder-content > .tree-folder {
    padding-left: 1.5rem;
}

.tree-folder-content .tree-folder-content .tree-item {
    padding-left: 3rem;
}

/* ── Drag-and-drop ───────────────────────────────────────────────── */

.tree-item.dragging {
    opacity: 0.4;
    cursor: grabbing;
}

.tree-folder.drag-over {
    background: var(--bg-hover);
    outline: 1px solid var(--accent);
    outline-offset: -1px;
    border-radius: 2px;
}

.tree-folder-content.drag-over {
    background: rgba(86, 156, 214, 0.08);
    outline: 1px dashed var(--accent);
    outline-offset: -1px;
    border-radius: 2px;
}