:root {
  --bg: #090713;
  --panel: #141128;
  --line: #2c2552;
  --text: #f5f1db;
  --muted: #bdb5de;
  --accent: #7ef8e1;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Trebuchet MS", "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at 15% 10%, #24174f 0, transparent 45%),
    radial-gradient(circle at 80% 15%, #13324b 0, transparent 40%),
    repeating-linear-gradient(
      to bottom,
      rgba(255,255,255,0.03) 0,
      rgba(255,255,255,0.03) 2px,
      transparent 2px,
      transparent 4px
    ),
    var(--bg);
  color: var(--text);
}

.app {
  max-width: 1180px;
  margin: 0 auto;
  padding: 24px 18px 28px;
}

.topbar h1 {
  margin: 10px 0 6px;
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  letter-spacing: 0.03em;
}

.topbar p {
  margin: 0;
  color: var(--muted);
}

.back-link {
  color: var(--accent);
  text-decoration: none;
}

.panel {
  margin-top: 18px;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--panel) 84%, black 16%);
  border-radius: 14px;
  display: grid;
  grid-template-columns: 330px 1fr;
  gap: 16px;
  padding: 16px;
  box-shadow: 0 22px 50px rgba(0, 0, 0, 0.42);
}

.controls {
  display: grid;
  gap: 12px;
}

label {
  display: grid;
  gap: 5px;
  color: var(--muted);
  font-size: 0.9rem;
}

input, select, button {
  border-radius: 8px;
  border: 1px solid #42397d;
  background: #0f0c20;
  color: var(--text);
  font: inherit;
}

input, select {
  padding: 9px 10px;
}

.button-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 6px;
}

button {
  padding: 10px 9px;
  cursor: pointer;
  transition: transform 120ms ease, filter 120ms ease;
}

button:hover {
  filter: brightness(1.12);
  transform: translateY(-1px);
}

button.primary {
  background: linear-gradient(135deg, #3f8efc, #42e9c7);
  color: #0d0920;
  font-weight: 700;
}

.hint {
  margin: 4px 0 0;
  font-size: 0.84rem;
  color: #9f98c5;
}

.preview {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px;
  background: #0b0919;
}

canvas {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 8px;
  image-rendering: crisp-edges;
}

@media (max-width: 980px) {
  .panel {
    grid-template-columns: 1fr;
  }
}