:root {
    /* Поверхности */
    --c-surface:       #aaa;
    --c-surface-alt:   #bbb;
    --c-surface-light: #ccc;
    --c-surface-input: #ddd;
    --c-surface-hover: #e6e6e6;

    /* Акценты */
    --c-primary:       #8fabbf;
    --c-primary-dark:  #80a4bf;
    --c-accent:        #4a90d9;
    --c-danger:        #c45050;
    --c-danger-dark:   #a83a3a;

    /* Утилитарные */
    --c-border:        #888;
    --c-hover:         #0002;
    --c-overlay:       #808080A0;
    --c-muted:         #888;

    /* Отступы */
    --sp-xs: 2px;
    --sp-sm: 4px;
    --sp-md: 8px;
    --sp-lg: 12px;

    /* Радиусы */
    --r-sm: 3px;
    --r-md: 4px;
    --r-lg: 8px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    user-select: none;
}

/* Scrollbar */

::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--c-border);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--c-muted);
}

[data-layout="hstack"] {
    display: flex;
    flex-direction: row;
}

[data-layout="vstack"] {
    display: flex;
    flex-direction: column;
}

[data-layout="vscroll"] {
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    min-height: 0;
}

[data-layout="vscroll"] > * { flex-shrink: 0; }

[data-layout="hscroll"] {
    display: flex;
    flex-direction: row;
    overflow-x: auto;
    min-width: 0;
}

[data-layout="hscroll"] > * { flex-shrink: 0; }

html, body {
    width: 100%;
    height: 100%;
    overflow: hidden;
}

#gfx-canvas {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
}

#app {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    pointer-events: none;
}

#app * {
    pointer-events: auto;
}

/* --- Утилитарные классы --- */

.selected {
    background-color: var(--c-primary);
}

.hoverable:hover:not(.selected) {
    background-color: var(--c-hover);
}

.text-muted {
    color: var(--c-muted);
}

/* --- Структурные классы --- */

.panel {
    background-color: var(--c-surface);
    padding: var(--sp-sm);
    border-color: var(--c-border);
}

.section {
    background-color: var(--c-surface-alt);
    border-radius: var(--r-md);
    padding: var(--sp-sm);
}

.scroll-section {
    background: var(--c-surface-alt);
    padding: var(--sp-sm);
    border-radius: 0 0 var(--r-md) var(--r-md);
    overflow-y: auto;
    min-height: 180px;
    max-height: 300px;
}

.group {
    border: 1px solid var(--c-border);
    border-radius: var(--r-md);
    padding: 2px;
}

.split-button:has(.split-arrow:hover) > .btn {
    background-color: var(--c-surface-light);
}

.popup-menu {
    background: var(--c-surface);
    border-radius: var(--r-md);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    z-index: 1000;
    min-width: 160px;
}

.header {
    padding: var(--sp-md) var(--sp-lg);
    border-bottom: 1px solid var(--c-border);
    font-weight: bold;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.btn {
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border-radius: var(--r-sm);
    padding: var(--sp-xs);
}

.btn:hover {
    background-color: var(--c-surface-light);
}

.btn.selected,
.btn.selected:hover {
    background-color: var(--c-primary-dark);
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.3);
}

.btn-text {
    padding: var(--sp-xs) var(--sp-md);
    background-color: var(--c-primary);
    border: 1px solid var(--c-primary-dark);
}

.btn-text:hover {
    background-color: var(--c-primary-dark);
}

.btn-danger {
    padding: var(--sp-xs) var(--sp-md);
    background-color: var(--c-danger);
    border: 1px solid var(--c-danger-dark);
    border-radius: var(--r-sm);
    cursor: pointer;
}

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

/* Кнопка закрытия окна: красный квадрат со скруглением и крестиком.
   Центрирование/курсор наследуются от .btn. */
.btn-close {
    width: 22px;
    height: 22px;
    padding: 0;
    font-size: 16px;
    line-height: 1;
    font-weight: bold;
    color: #fff;
    background-color: var(--c-danger);
    border-radius: var(--r-md);
}

.btn-close:hover {
    background-color: var(--c-danger-dark);
}

.input {
    padding: var(--sp-sm) var(--sp-md);
    border: 1px solid var(--c-border);
    border-radius: var(--r-md);
    background: var(--c-surface-input);
}

.tab {
    padding: var(--sp-sm) var(--sp-lg);
    cursor: pointer;
    border-radius: var(--r-md) var(--r-md) 0 0;
}

.tab:hover {
    background: var(--c-surface-hover);
}

.tab-active {
    background: var(--c-surface-alt);
}

.list-item {
    padding: var(--sp-sm) var(--sp-md);
    cursor: pointer;
    border-radius: var(--r-md);
    display: flex;
    justify-content: space-between;
}

.list-item:hover:not(.selected) {
    background: var(--c-hover);
}

.hover-actions {
    display: none;
}

.list-item:hover .hover-actions {
    display: flex;
    gap: var(--sp-xs);
    align-items: center;
}

.hover-actions .btn {
    padding: 0;
    height: 16px;
    width: 16px;
}

.hover-actions .btn img {
    height: 16px;
    width: 16px;
}

.dropzone {
    border: 2px dashed var(--c-border);
    border-radius: var(--r-lg);
    margin: var(--sp-md);
}

.dropzone-active {
    border-color: var(--c-accent);
    background: #4a90d920;
}

/* --- Resizer --- */

.resizer-wrap {
    position: relative;
}

.resizer {
    position: absolute;
    background: transparent;
    z-index: 10;
    transition: background-color 0.15s;
}

.resizer:hover,
.resizer-active {
    background-color: var(--c-accent);
}

.resizer-h {
    width: 4px;
    top: 0;
    bottom: 0;
    cursor: col-resize;
}

.resizer-h.resizer-right { right: -2px; }
.resizer-h.resizer-left  { left: -2px; }

.resizer-v {
    height: 4px;
    left: 0;
    right: 0;
    cursor: row-resize;
}

.resizer-v.resizer-bottom { bottom: -2px; }
.resizer-v.resizer-top    { top: -2px; }

/* --- Tree --- */

.tree-item {
    border-radius: var(--r-sm);
}

.tree-item:hover:not(:has(.tree-item:hover)):not(.selected) {
    background-color: var(--c-hover);
}

/* --- Drag & Drop индикатор позиции вставки (box-shadow/bg — без сдвига layout) --- */
.drop-before { box-shadow: inset 0 2px 0 var(--c-accent); }
.drop-after  { box-shadow: inset 0 -2px 0 var(--c-accent); }
.drop-into   { background-color: rgba(74, 144, 217, 0.22); }

/* --- Select --- */

select {
    all: unset;
    padding: var(--sp-xs);
    background: none;
    border: 1px solid #00000040;
    border-radius: var(--r-md);
    text-align: center;
}

select:hover {
    background: var(--c-surface-hover);
}

select option {
    background: var(--c-surface-hover);
    border-radius: var(--r-md);
}

/* --- Overlay --- */

#overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 100;
}

#overlay .overlay-layer {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--c-overlay);
}

/* --- Dialog --- */

.dialog:focus {
    outline: none;
}

.dialog {
    background: var(--c-surface);
    border-radius: var(--r-lg);
    min-width: 400px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

/* --- ColorPicker --- */

.color-picker {
    position: relative;
}

.color-picker-input {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
    border: none;
    padding: 0;
}

/* --- Checkbox --- */

.checkbox {
    appearance: none;
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    flex-shrink: 0;
    border: 1px solid var(--c-border);
    border-radius: var(--r-sm);
    background: transparent;
    cursor: pointer;
}

.checkbox:checked {
    position: relative;
}

.checkbox:checked::after {
    content: '';
    position: absolute;
    left: 3px;
    top: 0px;
    width: 5px;
    height: 8px;
    border: 1px solid #000D;
    border-top: none;
    border-left: none;
    transform: rotate(45deg);
}