:root {
  color-scheme: dark;
  --bg: #0f1115;
  --bg-panel: #171a21;
  --bg-panel-2: #1f232c;
  --border: #2a2f3a;
  --text: #e6e8ee;
  --text-dim: #9aa1b1;
  --accent: #7aa2ff;
  --pass: #66d19e;
  --fail: #ff7a7a;
  --radius: 10px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}

/* ===========================================================
   Layout
   =========================================================== */
.app {
  display: grid;
  grid-template-rows: auto 1fr;
  height: 100vh;
}

.top-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  padding: 10px 20px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
}

.top-bar h1 {
  margin: 0;
  font-size: 18px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-weight: 700;
  background: linear-gradient(90deg, #ff6b6b, #feca57, #48dbfb, #a55eea);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.top-bar label { color: var(--text-dim); font-size: 13px; }
.top-bar .control { display: flex; align-items: center; gap: 6px; }

.top-bar select,
.top-bar input[type="number"] {
  background: var(--bg-panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 5px 8px;
  border-radius: 6px;
  font-family: inherit;
}

.format-toggle {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
}
.format-toggle label {
  padding: 5px 10px;
  cursor: pointer;
  color: var(--text-dim);
  background: var(--bg-panel-2);
  transition: background 0.12s;
}
.format-toggle input { display: none; }
.format-toggle input:checked + label {
  background: var(--accent);
  color: #0f1115;
  font-weight: 600;
}

.checkbox {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
}
.checkbox input { cursor: pointer; }

.btn {
  background: var(--bg-panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 5px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-family: inherit;
  font-size: 13px;
  transition: background 0.12s, border-color 0.12s;
}
.btn:hover { background: #2a2f3a; border-color: var(--accent); }

.share-msg {
  font-size: 12px;
  color: var(--pass);
  opacity: 0;
  transition: opacity 0.2s;
}
.share-msg.visible { opacity: 1; }

/* ===========================================================
   Main area
   =========================================================== */
.main {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 16px;
  padding: 16px;
  min-height: 0;
}

@media (max-width: 900px) {
  .main { grid-template-columns: 1fr; }
}

.spiral-stage {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 400px;
  overflow: hidden;
}

.spiral {
  position: relative;
}

/* ===========================================================
   Swatch tile
   =========================================================== */
.swatch {
  position: absolute;
  border-radius: 6px;
  overflow: hidden;
  cursor: pointer;
  border: 2px solid transparent;
  transition: border-color 0.12s, transform 0.12s;
}
.swatch:hover { transform: scale(1.01); }
.swatch.selected { border-color: #fff; box-shadow: 0 0 0 2px var(--accent); }

.swatch .checker,
.swatch-preview .checker {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(45deg, #555 25%, transparent 25%),
    linear-gradient(-45deg, #555 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #555 75%),
    linear-gradient(-45deg, transparent 75%, #555 75%);
  background-size: 16px 16px;
  background-position: 0 0, 0 8px, 8px -8px, -8px 0;
  background-color: #888;
  opacity: 1;
}

.swatch .fill,
.swatch-preview .fill {
  position: absolute;
  inset: 0;
}

.swatch .label {
  position: relative;
  z-index: 1;
  padding: 8px 10px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-family: var(--mono);
  font-size: 11px;
  text-shadow: 0 1px 2px rgba(0,0,0,0.35);
  pointer-events: none;
}
.swatch .idx { font-weight: 700; opacity: 0.95; font-size: 10px; }
.swatch .hex { font-size: 13px; font-weight: 600; }
.swatch .name { opacity: 0.85; }

/* ===========================================================
   Editor panel
   =========================================================== */
.editor {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  overflow-y: auto;
}

.editor-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.editor-header h2 { margin: 0; font-size: 16px; }

.swatch-preview {
  position: relative;
  width: 56px;
  height: 56px;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
}

.channels {
  margin-bottom: 16px;
}
.channels h3 {
  margin: 0 0 8px;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  font-weight: 600;
}
.channels h3 .unit { opacity: 0.65; }

.channels .row {
  display: grid;
  grid-template-columns: 18px 1fr 60px;
  gap: 8px;
  align-items: center;
  margin-bottom: 6px;
}
.channels .row label {
  font-family: var(--mono);
  font-weight: 700;
  color: var(--text-dim);
  text-align: center;
}
.channels .row input[type="range"] { width: 100%; accent-color: var(--accent); }
.channels .row input[type="text"] {
  background: var(--bg-panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 4px 6px;
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 12px;
  width: 100%;
  text-align: right;
}

.direct-row {
  display: grid;
  grid-template-columns: 65px 1fr auto;
  gap: 8px;
  align-items: center;
  margin-bottom: 6px;
}
.direct-row label { color: var(--text-dim); font-size: 12px; }
.direct-row input {
  background: var(--bg-panel-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 5px 8px;
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 12px;
  width: 100%;
}
.copy-btn {
  background: var(--bg-panel-2);
  color: var(--text-dim);
  border: 1px solid var(--border);
  padding: 4px 8px;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
  font-size: 11px;
}
.copy-btn:hover { color: var(--text); border-color: var(--accent); }

.alpha-slider {
  margin-top: 8px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.alpha-slider.hidden { display: none; }
.alpha-slider label { color: var(--text-dim); font-size: 12px; }
.alpha-slider input[type="range"] { accent-color: var(--accent); }

/* ===========================================================
   Contrast panel
   =========================================================== */
.contrast { margin-top: 8px; }
.contrast h3 {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  margin: 0 0 8px;
  font-weight: 600;
}
.contrast-row {
  display: grid;
  grid-template-columns: 70px 70px 1fr 1fr;
  gap: 6px;
  align-items: center;
  padding: 3px 0;
  font-size: 12px;
  font-family: var(--mono);
}
.contrast-row .pair { color: var(--text-dim); }
.contrast-row .ratio { font-weight: 600; }
.contrast-row .pass { color: var(--pass); }
.contrast-row .fail { color: var(--fail); }