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

:root {
    /* Light Theme */
    --bg-app: #FFFFFF;
    --bg-toolbar: #F3F4F6;
    --bg-tab-bar: #E5E7EB;
    --bg-tab-active: #FFFFFF;
    --bg-tab-inactive: #E5E7EB;
    --border-color: #D1D5DB;
    
    --text-primary: #374151;
    --text-secondary: #6B7280;
    
    --accent-color: #374151;
    --hover-bg: rgba(0, 0, 0, 0.05);
    
    --modal-overlay: rgba(0, 0, 0, 0.5);
    --modal-bg: #FFFFFF;
    
    --toolbar-height: 48px;
    --tab-height: 36px;
    --status-height: 28px;
}

[data-theme="dark"] {
    /* Dark Theme */
    --bg-app: #0D1117;
    --bg-toolbar: #161B22;
    --bg-tab-bar: #010409;
    --bg-tab-active: #0D1117;
    --bg-tab-inactive: #010409;
    --border-color: #30363D;
    
    --text-primary: #C9D1D9;
    --text-secondary: #8B949E;
    
    --accent-color: #C9D1D9;
    --hover-bg: rgba(255, 255, 255, 0.1);
    
    --modal-overlay: rgba(0, 0, 0, 0.7);
    --modal-bg: #161B22;
}

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background-color: var(--bg-app);
    color: var(--text-primary);
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* --- TOOLBAR (Top) --- */
.app-header {
    height: var(--toolbar-height);
    background-color: var(--bg-toolbar);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    padding: 0 16px;
    justify-content: space-between;
    user-select: none;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 20px;
}

.logo {
    font-weight: 600;
    font-size: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-primary);
}

.toolbar-actions {
    display: flex;
    align-items: center;
    gap: 4px;
}

.toolbar-btn {
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 6px 10px;
    border-radius: 4px;
    font-size: 13px;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: background-color 0.2s;
    font-weight: 500;
}

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

.toolbar-btn i {
    width: 16px;
    height: 16px;
}

.toolbar-separator {
    width: 1px;
    height: 20px;
    background-color: var(--border-color);
    margin: 0 8px;
}

.toolbar-btn.active {
    background-color: var(--hover-bg);
    box-shadow: inset 0 0 0 1px var(--border-color);
}

/* --- TAB BAR --- */
.tab-bar-container {
    height: var(--tab-height);
    background-color: var(--bg-tab-bar);
    display: flex;
    overflow-x: auto;
    border-bottom: 1px solid var(--border-color);
}

.tab-item {
    display: flex;
    align-items: center;
    padding: 0 16px;
    background-color: var(--bg-tab-inactive);
    color: var(--text-secondary);
    border-right: 1px solid var(--border-color);
    cursor: pointer;
    font-size: 13px;
    min-width: 120px;
    max-width: 200px;
    user-select: none;
}

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

.tab-item:not(.active) {
    border-top: 2px solid transparent; 
}

.tab-item:hover:not(.active) {
    background-color: var(--hover-bg);
}

.tab-name {
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-right: 8px;
}

.tab-item.modified .tab-name {
    font-style: italic;
}

.tab-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background-color: var(--text-primary);
    display: none;
    margin-right: 6px;
    opacity: 0.7;
}

.tab-item.modified .tab-dot {
    display: block;
}

.tab-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 2px;
    border-radius: 3px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.tab-close:hover {
    background-color: rgba(0,0,0,0.1);
    color: var(--text-primary);
}

[data-theme="dark"] .tab-close:hover {
    background-color: rgba(255,255,255,0.2);
}

.tab-close i {
    width: 12px;
    height: 12px;
}

/* --- WORKSPACE --- */
.workspace {
    flex: 1;
    display: flex;
    overflow: hidden;
}

.editor-wrapper {
    flex: 1;
    position: relative;
    width: 100%;
}

#editor {
    width: 100%;
    height: 100%;
}

/* --- STATUS BAR --- */
.status-bar {
    height: var(--status-height);
    background-color: var(--bg-toolbar);
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    font-size: 11px;
    color: var(--text-secondary);
    user-select: none;
}

.status-group {
    display: flex;
    gap: 16px;
}

.status-item {
    display: flex;
    align-items: center;
    gap: 6px;
}

.status-item i {
    width: 12px;
    height: 12px;
}

/* --- MODALS --- */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--modal-overlay);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s;
}

.modal-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.modal-box {
    background-color: var(--bg-app);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    width: 400px;
    padding: 20px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

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

.modal-content {
    margin-bottom: 20px;
}

.input-group {
    display: flex;
    gap: 10px;
}

input, select {
    width: 100%;
    padding: 8px;
    background-color: var(--bg-toolbar);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-primary);
    outline: none;
    font-family: inherit;
}

input:focus, select:focus {
    border-color: var(--text-secondary);
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}

.btn {
    padding: 8px 16px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    background: transparent;
    color: var(--text-primary);
    cursor: pointer;
    font-size: 13px;
}

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

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

.btn-primary:hover {
    opacity: 0.9;
}

/* Drag Overlay */
.drag-overlay {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 20px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s;
}
.drag-overlay.active { opacity: 1; pointer-events: auto; }