:root {
  --bg-0: #02030a;
  --bg-1: #06081a;
  --panel: rgba(8, 12, 28, 0.78);
  --panel-bd: rgba(120, 140, 220, 0.22);
  --text: #e2e8f0;
  --text-dim: #94a3b8;
  --text-faint: #64748b;
  --accent: #7dd3fc;
  --accent-2: #c084fc;
  --accent-3: #f472b6;
  --warn: #fbbf24;
  --err: #f87171;
  --ok: #34d399;
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0; height: 100%;
  background: #000;
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

#stage {
  position: fixed;
  inset: 0;
  z-index: 0;
}
#stage canvas { display: block; }

/* ============ top bar ============ */
.topbar {
  position: fixed;
  top: 14px;
  left: 14px;
  right: 14px;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  background: var(--panel);
  border: 1px solid var(--panel-bd);
  border-radius: 10px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.45);
  z-index: 30;
  user-select: none;
  pointer-events: auto;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1 1 auto;
  min-width: 0;
}
.brand-icon {
  width: 32px; height: 32px;
  border-radius: 6px;
  flex: 0 0 auto;
  background: #0b0b18;
  border: 1px solid var(--panel-bd);
}
.brand h1 {
  margin: 0;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.5px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2), var(--accent-3));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.brand .sub {
  font-size: 11px;
  color: var(--text-faint);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.top-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
}
.identity {
  font-size: 11px;
  color: var(--text-dim);
  max-width: 240px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ============ buttons ============ */
.btn {
  font: inherit;
  font-size: 12px;
  font-weight: 500;
  background: linear-gradient(135deg, rgba(125, 211, 252, 0.18), rgba(192, 132, 252, 0.18));
  color: var(--text);
  border: 1px solid var(--panel-bd);
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}
.btn:hover { border-color: var(--accent); color: #fff; transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn.small { padding: 4px 9px; font-size: 11px; }
.btn.danger { color: var(--err); border-color: rgba(248, 113, 113, 0.35); }
.btn.danger:hover { background: rgba(248, 113, 113, 0.18); border-color: var(--err); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }

/* ============ panels ============ */
.panel {
  position: fixed;
  background: var(--panel);
  border: 1px solid var(--panel-bd);
  border-radius: 10px;
  padding: 12px 14px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.45);
  user-select: none;
  pointer-events: auto;
  z-index: 20;
}

/* ============ stats ============ */
#stats {
  top: 76px;
  right: 14px;
  min-width: 230px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 11px;
  line-height: 1.7;
  color: var(--text-dim);
}
#stats .row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
}
#stats .row b {
  color: var(--accent);
  font-weight: 600;
  font-size: 11px;
}

/* ============ control panel ============ */
#controlPanel {
  top: 76px;
  right: 14px;
  width: 320px;
  max-height: calc(100vh - 100px);
  overflow: hidden;
  transition: width 0.25s ease, max-height 0.25s ease, opacity 0.2s ease;
}
#controlPanel.collapsed {
  width: 80px;
  max-height: 44px;
  overflow: hidden;
}
#controlPanel.collapsed .panel-content {
  display: none;
}
#controlPanel.collapsed .panel-header .toggle-btn {
  margin-left: auto;
}

.panel-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--panel-bd);
  margin-bottom: 4px;
}
.panel-title {
  font-size: 12px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 1px;
  text-transform: uppercase;
}
.toggle-btn {
  margin-left: auto;
  min-width: 28px;
  justify-content: center;
}
#controlPanel.collapsed .panel-title {
  display: none;
}

#controlPanel::-webkit-scrollbar { width: 6px; }
#controlPanel::-webkit-scrollbar-thumb { background: rgba(120, 140, 220, 0.3); border-radius: 3px; }
#controlPanel::-webkit-scrollbar-track { background: transparent; }

.panel-content {
  overflow-y: auto;
  max-height: calc(100vh - 150px);
  scrollbar-width: thin;
  scrollbar-color: rgba(120, 140, 220, 0.3) transparent;
}
.panel-content::-webkit-scrollbar { width: 6px; }
.panel-content::-webkit-scrollbar-thumb { background: rgba(120, 140, 220, 0.3); border-radius: 3px; }
.panel-content::-webkit-scrollbar-track { background: transparent; }

.panel-section {
  padding: 10px 0;
  border-bottom: 1px dashed var(--panel-bd);
}
.panel-section:last-child { border-bottom: none; padding-bottom: 0; }
.panel-section:first-child { padding-top: 0; }

.panel-section h2 {
  margin: 0 0 8px;
  font-size: 12px;
  color: var(--accent);
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-dim);
  margin-bottom: 6px;
}
.row:last-child { margin-bottom: 0; }
.row-label {
  flex: 0 0 90px;
  font-size: 11px;
  color: var(--text-dim);
}
.row-val {
  flex: 0 0 70px;
  text-align: right;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 11px;
  color: var(--accent);
  font-weight: 500;
}
.row input[type=range] {
  flex: 1 1 auto;
  min-width: 0;
  accent-color: var(--accent);
  background: transparent;
}
.row select {
  flex: 1 1 auto;
  background: rgba(0, 0, 0, 0.4);
  color: var(--text);
  border: 1px solid var(--panel-bd);
  border-radius: 4px;
  padding: 3px 6px;
  font: inherit;
  font-size: 12px;
}
.row select option { background: #0b0b18; }

#presetSelect {
  width: 100%;
  background: rgba(0, 0, 0, 0.4);
  color: var(--text);
  border: 1px solid var(--panel-bd);
  border-radius: 4px;
  padding: 4px 6px;
  font: inherit;
  font-size: 12px;
  margin-bottom: 6px;
}

.color-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 6px 0;
  align-items: center;
}
.color-row:empty { display: none; }
.color-swatch {
  width: 32px; height: 28px;
  padding: 0;
  border: 1px solid var(--panel-bd);
  border-radius: 4px;
  background: transparent;
  cursor: pointer;
}
.color-swatch::-webkit-color-swatch { border: none; border-radius: 3px; }
.color-swatch::-webkit-color-swatch-wrapper { padding: 0; border-radius: 3px; }

.hint {
  font-size: 11px;
  color: var(--text-faint);
  line-height: 1.6;
}
.hint ul { margin: 4px 0 0 0; padding-left: 18px; }
.hint li { margin: 2px 0; }

/* ============ toast ============ */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: rgba(15, 20, 40, 0.92);
  border: 1px solid var(--panel-bd);
  color: var(--text);
  padding: 8px 16px;
  border-radius: 6px;
  font-size: 12px;
  z-index: 100;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.18s ease, transform 0.18s ease;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.5);
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ============ responsive ============ */
@media (max-width: 720px) {
  #controlPanel {
    width: calc(100vw - 28px);
    right: 14px;
    left: 14px;
    max-height: 50vh;
    top: auto;
    bottom: 14px;
  }
  #stats {
    top: 76px;
    right: 14px;
    min-width: 0;
    width: calc(100vw - 28px);
  }
  .brand .sub { display: none; }
}