:root {
  --bg: #f6f5f2;
  --ink: #1c1c1c;
  --muted: #5c5c5c;
  --line: #d6d4ce;
  --accent: #2a9d8f;
  --panel: #fff;
}
* { box-sizing: border-box; }
html, body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 14px/1.4 system-ui, Segoe UI, sans-serif;
}
header, main, footer { max-width: none; padding: 12px 16px; }
header { padding-bottom: 0; }
h1 { font-size: 20px; font-weight: 600; margin: 0 0 4px; }
.lede { color: var(--muted); margin: 0 0 10px; max-width: 90ch; }
.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 20px;
  align-items: end;
  padding: 8px 0 10px;
  border-bottom: 1px solid var(--line);
}
.toolbar label {
  display: flex;
  flex-direction: column;
  gap: 2px;
  font-size: 11px;
  color: var(--muted);
  min-width: 140px;
}
.toolbar label.check {
  flex-direction: row;
  align-items: center;
  gap: 6px;
  min-width: auto;
  padding-bottom: 4px;
  color: var(--ink);
  font-size: 13px;
}
.toolbar input[type="range"] { width: 160px; }
.toolbar output { color: var(--ink); font-variant-numeric: tabular-nums; }
.drop {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  min-height: 72px;
  margin: 12px 0;
  padding: 14px;
  border: 2px dashed var(--accent);
  background: var(--panel);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}
.drop.has-files { min-height: 48px; }
.drop span { color: var(--muted); font-size: 12px; }
.drop input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}
.drop.drag { background: #e7f6f3; }
#err { color: #9b1c1c; margin: 8px 0; font-size: 13px; }
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  margin: 10px 0 14px;
}
.panel-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  padding: 6px 10px;
  border-bottom: 1px solid var(--line);
  font-size: 13px;
}
.panel-bar .name { font-weight: 600; }
.panel-bar .meta { color: var(--muted); }
.panel-bar button {
  margin-left: auto;
  font: inherit;
  background: transparent;
  border: 1px solid var(--line);
  padding: 2px 8px;
  cursor: pointer;
}
.viewport {
  overflow-x: auto;
  overflow-y: hidden;
  height: 280px;
  background: #fff;
}
.viewport canvas { display: block; }
.keys {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 12px;
  color: var(--muted);
  padding: 6px 0 0;
}
.keys span::before {
  content: "";
  display: inline-block;
  width: 10px;
  height: 10px;
  margin-right: 5px;
  vertical-align: -1px;
}
.keys .A::before { background: #2ca02c; }
.keys .C::before { background: #1f77b4; }
.keys .G::before { background: #111; }
.keys .T::before { background: #d62728; }
.keys .hint::before { display: none; }
.keys .hint { margin-left: auto; }
footer { color: var(--muted); font-size: 12px; padding-bottom: 24px; }
a { color: var(--accent); }