:root {
  --bg: #14161a;
  --panel: #1c1f26;
  --panel-border: #2c3038;
  --text: #e8eaed;
  --text-dim: #9aa0aa;
  --accent: #4f8cff;
  --accent-hover: #3d78e6;
  --danger: #ff6b6b;
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

.topbar {
  padding: 20px 28px;
  border-bottom: 1px solid var(--panel-border);
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-left: 56px;
}
.topbar h1 { margin: 0; font-size: 20px; }

.menubar { display: flex; gap: 2px; margin-left: auto; }
.menu-item { position: relative; }
.menu-trigger {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-dim);
  padding: 8px 14px;
  border-radius: 6px;
  font-size: 13px;
  cursor: pointer;
}
.menu-trigger:hover { background: #2a2e37; color: var(--text); }
.menu-item.open .menu-trigger { background: #2a2e37; color: var(--text); border-color: var(--panel-border); }
.menu-dropdown {
  display: none;
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  min-width: 210px;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 8px;
  padding: 6px;
  flex-direction: column;
  gap: 2px;
  z-index: 30;
  box-shadow: 0 8px 24px rgba(0,0,0,.35);
}
.menu-item.open .menu-dropdown { display: flex; }
.menu-dropdown button {
  background: transparent;
  border: none;
  color: var(--text);
  text-align: left;
  padding: 8px 10px;
  border-radius: 5px;
  font-size: 13px;
  cursor: pointer;
}
.menu-dropdown button:hover:not(:disabled) { background: var(--accent); color: #fff; }
.menu-dropdown button:disabled { color: var(--text-dim); opacity: .5; cursor: not-allowed; }
.menu-sep { height: 1px; background: var(--panel-border); margin: 4px 2px; }

.left-toolbar {
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  width: 56px;
  background: var(--panel);
  border-right: 1px solid var(--panel-border);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 12px 0;
  gap: 6px;
  z-index: 20;
}
.tool-icon-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 6px;
  color: var(--text-dim);
  cursor: pointer;
  padding: 0;
}
.tool-icon-btn svg { width: 20px; height: 20px; stroke-linecap: round; stroke-linejoin: round; }
.tool-icon-btn:hover:not(:disabled) { background: #2a2e37; color: var(--text); }
.tool-icon-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }
.tool-icon-btn:disabled { opacity: .35; cursor: not-allowed; }
.tool-sep { width: 28px; height: 1px; background: var(--panel-border); margin: 4px 0; }
.left-toolbar[hidden] { display: none; }

.layout {
  display: grid;
  grid-template-columns: 1fr 360px;
  grid-template-rows: auto 1fr;
  gap: 20px;
  padding: 24px;
  max-width: 1400px;
  margin: 0 auto;
  margin-left: 56px;
}
.layout[hidden] { display: none; }

.panel {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  padding: 20px;
}

.upload-panel { grid-column: 2; grid-row: 1; }
.controls-panel { grid-column: 2; grid-row: 2; }
.preview-panel { grid-column: 1; grid-row: 1 / span 2; }

h2 { margin-top: 0; font-size: 15px; text-transform: uppercase; letter-spacing: .04em; color: var(--text-dim); }

.dropzone {
  border: 2px dashed var(--panel-border);
  border-radius: 8px;
  padding: 30px 16px;
  text-align: center;
  cursor: pointer;
  transition: border-color .15s;
}
.dropzone:hover, .dropzone.dragover { border-color: var(--accent); }
.dropzone p { margin: 6px 0; }
.hint { color: var(--text-dim); font-size: 12px; }

.start-screen {
  min-height: calc(100vh - 73px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px 24px;
}
.start-screen[hidden] { display: none; }
.start-inner { width: 100%; max-width: 640px; text-align: center; }
.start-title { margin: 0 0 8px; font-size: 30px; }
.start-tagline { color: var(--text-dim); margin: 0 0 32px; font-size: 14px; }
.dropzone-large { padding: 56px 24px; border-radius: 12px; }
.dropzone-large p:first-child { font-size: 17px; }

.start-presets {
  margin-top: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--text-dim);
}
.start-presets[hidden] { display: none; }
.preset-chip {
  background: #2a2e37;
  border: 1px solid var(--panel-border);
  color: var(--text);
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 13px;
  cursor: pointer;
}
.preset-chip:hover { border-color: var(--accent); }
.preset-chip.active { background: var(--accent); border-color: var(--accent); }

.start-features {
  margin: 36px 0 0;
  padding: 0;
  list-style: none;
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 10px;
  color: var(--text-dim);
  font-size: 13px;
}
.start-features li { padding-left: 22px; position: relative; }
.start-features li::before {
  content: "\2713";
  position: absolute;
  left: 0;
  color: var(--accent);
}

.file-info {
  margin-top: 14px;
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.6;
}
.file-info strong { color: var(--text); }

.field-row { margin-bottom: 16px; }
.field-row label { display: block; margin-bottom: 6px; font-size: 13px; color: var(--text-dim); }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.two-col[hidden] { display: none; }

.layers-list { list-style: none; margin: 0; padding: 0; border: 1px solid var(--panel-border); border-radius: 8px; overflow: hidden; }
.layer-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  background: #1a1d24;
  border-bottom: 1px solid var(--panel-border);
  cursor: grab;
}
.layer-row:last-child { border-bottom: none; }
.layer-row.dragging { opacity: .4; }
.layer-row.drag-over { outline: 2px dashed var(--accent); outline-offset: -2px; }
.layer-drag { color: var(--text-dim); font-size: 14px; line-height: 1; user-select: none; cursor: grab; }
.layer-eye {
  flex: none;
  width: 26px;
  height: 26px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--panel-border);
  border-radius: 5px;
  color: var(--text-dim);
  cursor: pointer;
  padding: 0;
}
.layer-eye svg { width: 15px; height: 15px; }
.layer-eye.active { color: var(--accent); border-color: var(--accent); }
.layer-label { font-size: 13px; color: var(--text); flex: 1; }
.layer-options {
  flex-basis: 100%;
  margin: 8px 0 2px 34px;
  padding-top: 8px;
  border-top: 1px solid var(--panel-border);
}
.layer-options[hidden] { display: none; }

.slider-row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.slider-row input[type="range"] {
  min-width: 90px;
  flex: 1;
  accent-color: var(--accent);
  background: transparent;
  padding: 0;
}
.slider-row input[type="number"] { width: 72px; flex: none; }

select, input[type="number"], input[type="text"] {
  width: 100%;
  background: #10121600;
  background-color: #0f1115;
  border: 1px solid var(--panel-border);
  color: var(--text);
  padding: 8px 10px;
  border-radius: 6px;
  font-size: 14px;
}
select:focus, input:focus { outline: 1px solid var(--accent); }

.checkbox-label { display: flex; align-items: center; gap: 8px; color: var(--text); font-size: 13px; }
.checkbox-label input { width: auto; }

input[type="color"] {
  width: 100%;
  height: 36px;
  padding: 2px;
  border: 1px solid var(--panel-border);
  border-radius: 6px;
  background: none;
}

.color-with-pick { display: flex; gap: 6px; align-items: center; }
.color-with-pick input[type="color"] { flex: 1; }
.pick-btn {
  flex: none;
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #2a2e37;
  border: 1px solid var(--panel-border);
  border-radius: 6px;
  color: var(--text-dim);
  cursor: pointer;
  padding: 0;
}
.pick-btn svg { width: 16px; height: 16px; }
.pick-btn:hover:not(:disabled) { border-color: var(--accent); color: var(--text); }
.pick-btn:disabled { opacity: .4; cursor: not-allowed; }
.pick-btn.active { background: var(--accent); border-color: var(--accent); color: #fff; }

.preview-frame.picking { cursor: crosshair; }
.preview-frame.picking img, .preview-frame.picking canvas { cursor: crosshair; }

.channel-table { width: 100%; border-collapse: collapse; margin-bottom: 18px; font-size: 13px; }
.channel-table th {
  text-align: left;
  color: var(--text-dim);
  font-weight: 500;
  padding: 6px 4px;
  border-bottom: 1px solid var(--panel-border);
}
.channel-table td { padding: 6px 4px; vertical-align: middle; }
.channel-table input[type="number"] { width: 70px; }
.channel-table input[type="color"] {
  width: 36px; height: 28px; padding: 0; border: 1px solid var(--panel-border);
  border-radius: 4px; background: none;
}
.channel-swatch {
  display: inline-block; width: 14px; height: 14px; border-radius: 3px; margin-right: 6px; vertical-align: middle;
}

.button-col { display: flex; flex-direction: column; gap: 8px; justify-content: flex-end; }

.btn {
  background: #2a2e37;
  color: var(--text);
  border: 1px solid var(--panel-border);
  padding: 10px 16px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
}
.btn:hover { border-color: var(--accent); }
.btn-primary { background: var(--accent); border-color: var(--accent); }
.btn-primary:hover { background: var(--accent-hover); }
.btn:disabled { opacity: .5; cursor: not-allowed; }

.status { min-height: 18px; font-size: 13px; color: var(--text-dim); }
.status.error { color: var(--danger); }

.preview-tabs { display: flex; gap: 6px; margin-bottom: 12px; }
.tab-btn {
  background: transparent;
  border: 1px solid var(--panel-border);
  color: var(--text-dim);
  padding: 7px 16px;
  border-radius: 6px;
  font-size: 13px;
  cursor: pointer;
}
.tab-btn:hover { color: var(--text); }
.tab-btn.active { background: var(--accent); border-color: var(--accent); color: #fff; }

.preview-frame {
  position: relative;
  border-radius: 8px;
  min-height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-image:
    linear-gradient(45deg, #2a2d33 25%, transparent 25%),
    linear-gradient(-45deg, #2a2d33 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #2a2d33 75%),
    linear-gradient(-45deg, transparent 75%, #2a2d33 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
  background-color: #1a1c21;
  overflow: auto;
}
.preview-frame img { max-width: 100%; max-height: 70vh; display: block; }
.preview-frame canvas {
  position: absolute;
  cursor: crosshair;
  touch-action: none;
}

.toolbox {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: flex-end;
  gap: 20px;
  flex-wrap: wrap;
  padding: 12px 28px;
  background: var(--panel);
  border-bottom: 1px solid var(--panel-border);
  margin-left: 56px;
}
.toolbox .tool-group { display: flex; flex-direction: column; gap: 4px; }
.toolbox .tool-group[hidden] { display: none; }
.toolbox label { font-size: 12px; color: var(--text-dim); }
.toolbox select { min-width: 170px; }
.toolbox-actions { display: flex; gap: 8px; }
.toolbox select:disabled, .toolbox button:disabled { opacity: .4; cursor: not-allowed; }
.toolbox[hidden] { display: none; }
.btn-small { padding: 7px 12px; font-size: 13px; }

@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; }
  .upload-panel, .controls-panel, .preview-panel { grid-column: 1; grid-row: auto; }
}