:root {
    /* Light Theme */
    --bg-color: #f0f2f5;
    --text-color: #1a1a1a;
    --sidebar-bg: rgba(255, 255, 255, 0.85);
    --card-bg: #ffffff;
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --border-color: #e2e8f0;
    --glass-border: rgba(255, 255, 255, 0.5);
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --font-main: 'Outfit', sans-serif;
}

[data-theme="dark"] {
    --bg-color: #0f172a;
    --text-color: #f1f5f9;
    --sidebar-bg: rgba(30, 41, 59, 0.85);
    --card-bg: #1e293b;
    --primary-color: #3b82f6;
    --primary-hover: #60a5fa;
    --secondary-color: #94a3b8;
    --border-color: #334155;
    --glass-border: rgba(255, 255, 255, 0.1);
}

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

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-color);
    height: 100vh;
    overflow: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Layout */
.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* Sidebar */
.sidebar {
    width: 320px;
    background: var(--sidebar-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-right: 1px solid var(--glass-border);
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    z-index: 10;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s ease;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.brand i {
    font-size: 1.75rem;
}

.brand h1 {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--text-color);
}

/* Controls */
.controls {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.divider {
    height: 1px;
    background-color: var(--border-color);
    margin: 0.5rem 0;
}

/* Buttons */
.btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    border-radius: 0.5rem;
    border: none;
    font-family: var(--font-main);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.95rem;
}

.btn.primary {
    background-color: var(--primary-color);
    color: white;
}

.btn.primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

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

.btn.success {
    background-color: var(--success-color);
    color: white;
}

.btn.ghost {
    background-color: transparent;
    color: var(--secondary-color);
}

.btn.ghost:hover {
    background-color: rgba(0, 0, 0, 0.05);
    color: var(--text-color);
}

.btn.danger {
    background-color: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

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

.icon-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    color: var(--text-color);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
}

.icon-btn:hover {
    background: var(--bg-color);
    transform: scale(1.05);
}

/* Stats Panel */
.stats-panel {
    margin-top: auto;
    padding: 1rem;
    background: rgba(0, 0, 0, 0.03);
    border-radius: 0.75rem;
}

.stats-panel h3 {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--secondary-color);
    margin-bottom: 0.75rem;
}

.stat-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.theme-toggle {
    margin-top: 1rem;
    display: flex;
    justify-content: flex-end;
}

/* Canvas Area */
.canvas-area {
    flex: 1;
    position: relative;
    background-image: radial-gradient(var(--border-color) 1px, transparent 1px);
    background-size: 20px 20px;
    overflow: hidden;
    cursor: grab;
}

.canvas-area:active {
    cursor: grabbing;
}

.canvas-controls {
    position: absolute;
    bottom: 2rem;
    right: 2rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    z-index: 5;
}

#tree-canvas {
    display: block;
    width: 100%;
    height: 100%;
}

/* Empty State */
.empty-state {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: var(--secondary-color);
    display: none;
    /* Hidden by default, shown via JS */
}

.empty-state.visible {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state h2 {
    color: var(--text-color);
}

/* Modals */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.modal-overlay:not(.hidden) {
    opacity: 1;
    pointer-events: auto;
}

.modal {
    background: var(--card-bg);
    width: 90%;
    max-width: 600px;
    border-radius: 1rem;
    box-shadow: var(--shadow-lg);
    display: flex;
    flex-direction: column;
    max-height: 90vh;
    transform: translateY(20px);
    transition: transform 0.3s ease;
}

.modal-overlay:not(.hidden) .modal {
    transform: translateY(0);
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-body {
    padding: 1.5rem;
    overflow-y: auto;
    flex: 1;
    min-height: 0;
}

.modal-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: 1rem;
    justify-content: flex-end;
    flex-shrink: 0;
    background: var(--card-bg);
    border-bottom-left-radius: 1rem;
    border-bottom-right-radius: 1rem;
}

.close-modal {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    color: var(--secondary-color);
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-row {
    display: flex;
    gap: 1rem;
}

.form-row .form-group {
    flex: 1;
}

label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
}

input,
select,
textarea {
    width: 100%;
    padding: 0.75rem;
    border-radius: 0.5rem;
    border: 1px solid var(--border-color);
    background: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    font-size: 1rem;
    transition: border-color 0.2s;
}

input:focus,
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.1);
}

/* Avatar Upload */
.avatar-upload {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.avatar-preview {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: var(--bg-color);
    border: 2px dashed var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    font-size: 2rem;
    color: var(--secondary-color);
}

.avatar-preview img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* Toast */
.toast-container {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 200;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toast {
    background: var(--card-bg);
    color: var(--text-color);
    padding: 0.75rem 1.5rem;
    border-radius: 2rem;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    animation: slideUp 0.3s ease;
    border: 1px solid var(--border-color);
}

.toast.success i {
    color: var(--success-color);
}

.toast.error i {
    color: var(--danger-color);
}

@keyframes slideUp {
    from {
        transform: translateY(20px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

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

    .sidebar {
        width: 100%;
        height: auto;
        padding: 0.75rem;
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
        flex-wrap: wrap;
        gap: 0.5rem;
        z-index: 20;
    }

    .brand {
        margin-bottom: 0;
        margin-right: auto;
    }

    .controls {
        display: flex;
        flex-direction: row;
        gap: 0.5rem;
        overflow-x: auto;
        padding-bottom: 0;
        align-items: center;
        max-width: 100%;
    }

    /* Hide text on some buttons for mobile to save space, show only icons */
    .controls .btn span {
        display: none;
    }

    .controls .btn {
        padding: 0.5rem;
    }

    .view-as-control {
        display: none;
        /* Hide view as on mobile for space */
    }

    .divider {
        display: none;
    }

    .stats-panel {
        display: none;
    }

    .theme-toggle {
        margin-top: 0;
    }

    .canvas-area {
        height: calc(100vh - 70px);
    }

    .modal {
        width: 95%;
        max-height: 95vh;
    }

    .modal-body {
        padding: 1rem;
    }

    .modal-footer {
        padding: 1rem;
    }
}

/* Searchable Select Styles */
.search-select-wrapper {
    position: relative;
    width: 100%;
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 0.25rem;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.25rem;
}

.search-select-wrapper:focus-within {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.1);
}

.search-input {
    flex: 1;
    min-width: 100px;
    border: none;
    background: transparent;
    padding: 0.5rem;
    font-size: 0.95rem;
    color: var(--text-primary);
    outline: none;
}

.dropdown-icon {
    padding: 0 0.5rem;
    color: var(--text-secondary);
    cursor: pointer;
}

.search-results {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    margin-top: 0.25rem;
    max-height: 200px;
    overflow-y: auto;
    z-index: 100;
    box-shadow: var(--shadow-lg);
}

.search-item {
    padding: 0.75rem 1rem;
    cursor: pointer;
    transition: background 0.2s;
    border-bottom: 1px solid var(--border-color);
}

.search-item:last-child {
    border-bottom: none;
}

.search-item:hover,
.search-item.selected {
    background: var(--bg-color);
}

.tag-custom {
    background: #e0f2fe;
    color: #0369a1;
    padding: 0.1rem 0.4rem;
    border-radius: 0.25rem;
    font-size: 0.8em;
    margin-left: 0.5rem;
}

.tag-alias {
    color: var(--text-secondary);
    font-style: italic;
    margin-left: 0.5rem;
}

.selected-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
    padding-left: 0.25rem;
}

.chip {
    background: var(--primary-light);
    color: var(--primary-color);
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

.chip .remove-chip {
    cursor: pointer;
    opacity: 0.7;
}

.chip .remove-chip:hover {
    opacity: 1;
}

.no-results {
    padding: 1rem;
    text-align: center;
    color: var(--text-secondary);
}