* { box-sizing: border-box; }

:root {
  --bg: #0b0d10;
  --panel: #14181d;
  --panel-2: #1b2027;
  --border: #262c34;
  --text: #e6e8eb;
  --muted: #8b93a1;
  --accent: #4f8cff;
  --accent-2: #3a74e0;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  background: radial-gradient(1200px 600px at 50% -10%, #12161b 0%, var(--bg) 60%);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

.app {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 20px 60px;
}

.app-header h1 {
  margin: 0 0 6px;
  font-size: 26px;
  letter-spacing: -0.02em;
}

.subtitle {
  margin: 0 0 24px;
  color: var(--muted);
  font-size: 14px;
}

.panel {
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  box-shadow: 0 10px 30px rgba(0,0,0,.35), inset 0 1px 0 rgba(255,255,255,.03);
}

.field { display: flex; flex-direction: column; gap: 6px; }
.field--full { margin-bottom: 14px; }

.field label {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--muted);
}

.field label span {
  color: var(--text);
  font-weight: 700;
}

.field input[type="text"],
.field select {
  width: 100%;
  padding: 10px 12px;
  background: #0e1116;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 9px;
  font-size: 15px;
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}

.field input[type="text"]:focus,
.field select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(79,140,255,.18);
}

.field select optgroup {
  color: var(--muted);
  font-size: 12px;
}

.field select option {
  color: var(--text);
  background: #0e1116;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
}

input[type="color"] {
  width: 100%;
  height: 40px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 9px;
  background: #0e1116;
  cursor: pointer;
}
input[type="color"]::-webkit-color-swatch-wrapper { padding: 4px; }
input[type="color"]::-webkit-color-swatch { border: none; border-radius: 6px; }

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 4px;
  background: #0e1116;
  border: 1px solid var(--border);
  outline: none;
  margin-top: 8px;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid #0b0d10;
  cursor: pointer;
}
input[type="range"]::-moz-range-thumb {
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid #0b0d10;
  cursor: pointer;
}

.actions {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-top: 18px;
  flex-wrap: wrap;
}

button {
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  color: #fff;
  background: linear-gradient(180deg, var(--accent), var(--accent-2));
  border: 1px solid #2b5bc0;
  border-radius: 10px;
  cursor: pointer;
  transition: transform .08s, filter .15s;
}
button:hover { filter: brightness(1.08); }
button:active { transform: translateY(1px); }
button:disabled { opacity: .55; cursor: progress; }

.status { color: var(--muted); font-size: 13px; }

.led-wrap {
  margin-top: 26px;
  padding: 20px;
  background: linear-gradient(180deg, #0d1015, #05070a);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow:
    inset 0 0 60px rgba(0,0,0,.6),
    0 10px 30px rgba(0,0,0,.4);
  display: flex;
  justify-content: center;
  overflow-x: auto;
}

#ledCanvas {
  display: block;
  max-width: 100%;
  height: auto;
  image-rendering: pixelated;
  border-radius: 8px;
}