@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=JetBrains+Mono:wght@400;500&display=swap');

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

:root {
    --ui-bg: #080d16;
    --ui-sidebar: #0b1120;
    --ui-surface: #111827;
    --ui-surface-2: #1a2236;
    --ui-border: rgba(255,255,255,0.06);
    --ui-border-hover: rgba(255,255,255,0.12);
    --ui-text: #e2e8f0;
    --ui-text-muted: #4b5a6e;
    --ui-text-dim: #64748b;
    --ui-accent: #A98EF5;
    --ui-accent-dim: rgba(169,142,245,0.15);
    --ui-accent-glow: rgba(169,142,245,0.25);
    --ui-danger: #f87171;
    --ui-success: #34d399;
    --ui-radius: 6px;
    --sidebar-w: 340px;
    --topbar-h: 52px;
}

html, body {
    height: 100%;
    overflow: hidden;
    font-family: 'Inter', -apple-system, sans-serif;
    font-size: 13px;
    color: var(--ui-text);
    background: var(--ui-bg);
    -webkit-font-smoothing: antialiased;
}

/* ── Layout ── */
.builder-layout {
    display: grid;
    grid-template-columns: var(--sidebar-w) 1fr;
    grid-template-rows: var(--topbar-h) 1fr;
    height: 100vh;
}

/* ── Top Bar ── */
.topbar {
    grid-column: 1 / -1;
    display: flex;
    align-items: center;
    padding: 0 20px;
    border-bottom: 1px solid var(--ui-border);
    background: var(--ui-sidebar);
    gap: 16px;
}

.topbar-brand {
    display: flex;
    align-items: baseline;
    gap: 8px;
    flex: 1;
}

.topbar-brand .brand-name {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 0.15em;
    color: var(--ui-text);
    text-transform: uppercase;
}

.topbar-brand .brand-tag {
    font-size: 10px;
    font-weight: 400;
    letter-spacing: 0.1em;
    color: var(--ui-accent);
    text-transform: uppercase;
    background: var(--ui-accent-dim);
    padding: 2px 7px;
    border-radius: 3px;
    border: 1px solid rgba(169,142,245,0.2);
}

.topbar-actions {
    display: flex;
    gap: 8px;
    align-items: center;
}

/* ── Sidebar ── */
.sidebar {
    border-right: 1px solid var(--ui-border);
    background: var(--ui-sidebar);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.tab-bar {
    display: flex;
    border-bottom: 1px solid var(--ui-border);
    flex-shrink: 0;
}

.tab-btn {
    flex: 1;
    padding: 11px 0;
    background: none;
    border: none;
    color: var(--ui-text-muted);
    font-size: 11px;
    font-family: inherit;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    cursor: pointer;
    transition: color 0.2s, background 0.2s;
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
}

.tab-btn:hover { color: var(--ui-text-dim); }
.tab-btn.active {
    color: var(--ui-accent);
    border-bottom-color: var(--ui-accent);
}

.panel {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.panel.hidden { display: none; }

/* ── Scrollbar ── */
.panel::-webkit-scrollbar, #json-editor::-webkit-scrollbar { width: 4px; }
.panel::-webkit-scrollbar-track, #json-editor::-webkit-scrollbar-track { background: transparent; }
.panel::-webkit-scrollbar-thumb, #json-editor::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.08);
    border-radius: 2px;
}

/* ── Preview Area ── */
.preview-area {
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: #030712;
}

.preview-toolbar {
    display: flex;
    align-items: center;
    padding: 0 16px;
    height: 38px;
    border-bottom: 1px solid var(--ui-border);
    background: rgba(0,0,0,0.3);
    flex-shrink: 0;
    gap: 10px;
}

.preview-toolbar-label {
    font-size: 10px;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--ui-text-muted);
    flex: 1;
}

.preview-status {
    font-size: 10px;
    color: var(--ui-text-muted);
    display: flex;
    align-items: center;
    gap: 5px;
}

.status-dot {
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--ui-success);
    box-shadow: 0 0 6px var(--ui-success);
}

.status-dot.updating {
    background: #fbbf24;
    box-shadow: 0 0 6px #fbbf24;
    animation: pulse 1s ease infinite;
}

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

#preview-frame {
    flex: 1;
    border: none;
    width: 100%;
}

/* ── Buttons ── */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 14px;
    border-radius: var(--ui-radius);
    font-family: inherit;
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s;
    border: 1px solid transparent;
    white-space: nowrap;
}

.btn-primary {
    background: var(--ui-accent);
    color: #0a0a0a;
    border-color: var(--ui-accent);
}
.btn-primary:hover {
    background: #c4aff8;
    box-shadow: 0 0 12px var(--ui-accent-glow);
}

.btn-ghost {
    background: transparent;
    color: var(--ui-text-dim);
    border-color: var(--ui-border);
}
.btn-ghost:hover {
    background: var(--ui-surface);
    color: var(--ui-text);
    border-color: var(--ui-border-hover);
}

.btn-danger {
    background: transparent;
    color: var(--ui-danger);
    border-color: rgba(248,113,113,0.2);
}
.btn-danger:hover {
    background: rgba(248,113,113,0.08);
    border-color: var(--ui-danger);
}

.btn-icon {
    padding: 6px 8px;
    background: transparent;
    border: 1px solid var(--ui-border);
    color: var(--ui-text-dim);
    border-radius: var(--ui-radius);
    font-family: inherit;
    font-size: 13px;
    cursor: pointer;
    transition: all 0.15s;
    line-height: 1;
}
.btn-icon:hover {
    background: var(--ui-surface);
    color: var(--ui-text);
    border-color: var(--ui-border-hover);
}

.btn-sm { padding: 4px 10px; font-size: 11px; }
.btn-xs { padding: 3px 8px; font-size: 10px; }
.btn-full { width: 100%; justify-content: center; }

/* ── Form Elements ── */
.field { display: flex; flex-direction: column; gap: 5px; }
.field label {
    font-size: 10px;
    font-weight: 500;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--ui-text-muted);
}

input[type="text"], input[type="url"], select, textarea {
    width: 100%;
    background: var(--ui-surface);
    border: 1px solid var(--ui-border);
    border-radius: var(--ui-radius);
    color: var(--ui-text);
    font-family: inherit;
    font-size: 12px;
    padding: 7px 10px;
    outline: none;
    transition: border-color 0.15s;
}

input[type="text"]:focus, input[type="url"]:focus, select:focus, textarea:focus {
    border-color: var(--ui-accent);
}

select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    padding-right: 30px;
}

input[type="range"] {
    width: 100%;
    accent-color: var(--ui-accent);
    cursor: pointer;
    height: 4px;
}

input[type="color"] {
    width: 36px;
    height: 28px;
    padding: 2px;
    border-radius: 4px;
    border: 1px solid var(--ui-border);
    background: var(--ui-surface);
    cursor: pointer;
    flex-shrink: 0;
}
input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; border-radius: 2px; }
input[type="color"]::-webkit-color-swatch { border: none; border-radius: 2px; }

/* ── Toggle ── */
.toggle-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 2px 0;
}

.toggle-label {
    font-size: 12px;
    color: var(--ui-text-dim);
}

.toggle {
    position: relative;
    width: 32px;
    height: 18px;
    flex-shrink: 0;
}
.toggle input { opacity: 0; width: 0; height: 0; }
.toggle-track {
    position: absolute;
    inset: 0;
    background: var(--ui-surface-2);
    border-radius: 9px;
    cursor: pointer;
    transition: background 0.2s;
    border: 1px solid var(--ui-border);
}
.toggle input:checked + .toggle-track { background: var(--ui-accent); border-color: var(--ui-accent); }
.toggle-track::after {
    content: '';
    position: absolute;
    left: 2px;
    top: 50%;
    transform: translateY(-50%);
    width: 12px; height: 12px;
    background: white;
    border-radius: 50%;
    transition: transform 0.2s;
}
.toggle input:checked + .toggle-track::after { transform: translate(14px,-50%); }

/* ── Slider Row ── */
.slider-row {
    display: flex;
    align-items: center;
    gap: 8px;
}
.slider-row input[type="range"] { flex: 1; }
.slider-value {
    font-size: 11px;
    color: var(--ui-accent);
    font-family: 'JetBrains Mono', monospace;
    min-width: 32px;
    text-align: right;
}

/* ── Section dividers ── */
.section-header {
    font-size: 10px;
    font-weight: 600;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--ui-text-muted);
    padding: 6px 0 4px;
    border-bottom: 1px solid var(--ui-border);
    margin-bottom: 4px;
    margin-top: 4px;
}

/* ── Node List ── */
.data-toolbar {
    display: flex;
    gap: 6px;
    align-items: center;
    margin-bottom: 4px;
}

.data-mode-toggle {
    display: flex;
    background: var(--ui-surface);
    border: 1px solid var(--ui-border);
    border-radius: var(--ui-radius);
    overflow: hidden;
}
.data-mode-toggle button {
    padding: 5px 12px;
    background: none;
    border: none;
    color: var(--ui-text-muted);
    font-size: 11px;
    font-family: inherit;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s;
    letter-spacing: 0.04em;
}
.data-mode-toggle button.active {
    background: var(--ui-accent-dim);
    color: var(--ui-accent);
}

.node-filter {
    flex: 0 0 auto;
    height: 32px;
    padding: 5px 9px;
    background: var(--ui-surface);
    border: 1px solid var(--ui-border);
    border-radius: var(--ui-radius);
    color: var(--ui-text);
    font-family: inherit;
    font-size: 11px;
    outline: none;
}
.node-filter::placeholder { color: var(--ui-text-muted); }
.node-filter:focus { border-color: var(--ui-accent); }

.node-list { display: flex; flex-direction: column; gap: 3px; }

.node-item {
    display: flex;
    align-items: center;
    padding: 7px 10px;
    border-radius: var(--ui-radius);
    background: var(--ui-surface);
    border: 1px solid var(--ui-border);
    cursor: pointer;
    transition: all 0.15s;
    gap: 8px;
}
.node-item:hover {
    border-color: var(--ui-border-hover);
    background: var(--ui-surface-2);
}
.node-item.active {
    border-color: var(--ui-accent);
    background: var(--ui-accent-dim);
}
.node-item-name {
    flex: 1;
    font-size: 12px;
    color: var(--ui-text);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.node-item-count {
    font-size: 10px;
    color: var(--ui-text-muted);
    background: var(--ui-surface-2);
    padding: 2px 6px;
    border-radius: 10px;
}
.node-item.active .node-item-count {
    background: rgba(169,142,245,0.2);
    color: var(--ui-accent);
}

/* ── Node Editor ── */
.node-editor {
    background: var(--ui-surface);
    border: 1px solid var(--ui-border);
    border-radius: var(--ui-radius);
    padding: 12px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.node-editor-header {
    display: flex;
    align-items: center;
    gap: 8px;
    justify-content: space-between;
}

.node-editor-title {
    font-size: 10px;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--ui-text-muted);
    font-weight: 500;
}

.children-table {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.child-row {
    display: flex;
    gap: 4px;
    align-items: center;
}

.child-row input {
    flex: 1;
    padding: 5px 8px;
    font-size: 11px;
}

.child-row input:first-child { flex: 1.4; }

/* ── JSON Editor ── */
#json-editor {
    flex: 1;
    background: var(--ui-surface);
    border: 1px solid var(--ui-border);
    border-radius: var(--ui-radius);
    color: var(--ui-text);
    font-family: 'JetBrains Mono', monospace;
    font-size: 11px;
    padding: 12px;
    resize: none;
    outline: none;
    line-height: 1.6;
    min-height: 300px;
}
#json-editor:focus { border-color: var(--ui-accent); }
#json-error {
    font-size: 10px;
    color: var(--ui-danger);
    min-height: 14px;
}

/* ── Theme Panel ── */
.color-row {
    display: flex;
    align-items: center;
    gap: 8px;
}
.color-row label {
    flex: 1;
    font-size: 11px;
    color: var(--ui-text-dim);
}
.color-row .color-value {
    font-size: 10px;
    font-family: 'JetBrains Mono', monospace;
    color: var(--ui-text-muted);
    min-width: 80px;
    text-align: right;
}

.preset-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 6px;
}

.preset-btn {
    padding: 7px 4px;
    background: var(--ui-surface);
    border: 1px solid var(--ui-border);
    border-radius: var(--ui-radius);
    color: var(--ui-text-dim);
    font-size: 10px;
    font-family: inherit;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s;
    text-align: center;
    letter-spacing: 0.04em;
}
.preset-btn:hover {
    border-color: var(--ui-border-hover);
    color: var(--ui-text);
    background: var(--ui-surface-2);
}
.preset-btn.active {
    border-color: var(--ui-accent);
    color: var(--ui-accent);
    background: var(--ui-accent-dim);
}
.preset-swatch {
    width: 12px; height: 12px;
    border-radius: 50%;
    display: inline-block;
    vertical-align: middle;
    margin-right: 4px;
    border: 1px solid rgba(255,255,255,0.15);
}