:root {
  color-scheme: light dark;
  --bg: #0d1117;
  --panel: #161b22;
  --panel-2: #1c2330;
  --border: #2a3038;
  --text: #e6edf3;
  --dim: #8b949e;
  --accent: #2f81f7;
  --accent-2: #1f6feb;
  --good: #3fb950;
  --warn: #d29922;
}
@media (prefers-color-scheme: light) {
  :root {
    --bg: #f6f8fa;
    --panel: #ffffff;
    --panel-2: #f0f3f6;
    --border: #d0d7de;
    --text: #1f2328;
    --dim: #57606a;
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font: 15px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

header {
  padding: 32px 24px 8px;
  text-align: center;
}
header h1 { margin: 0; font-size: 28px; letter-spacing: -0.01em; }
.tag { color: var(--dim); margin-top: 4px; }

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 16px 24px 64px;
}

section { margin-top: 24px; }

.drop {
  border: 2px dashed var(--border);
  background: var(--panel);
  border-radius: 12px;
  padding: 48px 16px;
  text-align: center;
  transition: border-color 120ms, background 120ms;
}
.drop.dragging { border-color: var(--accent); background: var(--panel-2); }
.drop strong { font-size: 18px; }
.dim { color: var(--dim); }

#config {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
}
.row { display: flex; align-items: center; gap: 16px; margin-bottom: 16px; }
.row label { width: 90px; color: var(--dim); flex-shrink: 0; }

.presets { display: flex; flex-wrap: wrap; gap: 8px; }
.preset {
  padding: 8px 12px;
  border: 1px solid var(--border);
  background: var(--panel-2);
  color: var(--text);
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
}
.preset .label { font-weight: 600; }
.preset .desc { display: block; color: var(--dim); font-size: 12px; margin-top: 2px; max-width: 220px; }
.preset.active { border-color: var(--accent); background: rgba(47, 129, 247, 0.12); }

select, button, input {
  font: inherit;
  color: var(--text);
}
select {
  padding: 8px 10px;
  border: 1px solid var(--border);
  background: var(--panel-2);
  border-radius: 8px;
}

button.primary, a.primary {
  display: inline-block;
  background: var(--accent);
  color: white;
  border: 0;
  padding: 10px 18px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  text-decoration: none;
}
button.primary:hover, a.primary:hover { background: var(--accent-2); }
button.primary:disabled { opacity: 0.5; cursor: not-allowed; }

button#pick {
  background: transparent;
  color: var(--accent);
  border: 0;
  cursor: pointer;
  text-decoration: underline;
  font: inherit;
  padding: 0;
}

#status {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 20px;
  color: var(--dim);
}

.metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  margin-bottom: 16px;
}
.metric {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
}
.metric .label { color: var(--dim); font-size: 12px; text-transform: uppercase; letter-spacing: 0.04em; }
.metric span:last-child { font-size: 18px; font-weight: 600; margin-top: 4px; }
.metric.primary { border-color: var(--good); }
.metric.primary span:last-child { color: var(--good); }

.warn {
  background: rgba(210, 153, 34, 0.12);
  border: 1px solid var(--warn);
  color: var(--warn);
  border-radius: 8px;
  padding: 10px 14px;
  margin-bottom: 12px;
}

.compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 12px;
}
.compare h3 { margin: 0 0 8px; font-size: 14px; color: var(--dim); }
.compare canvas {
  width: 100%;
  height: auto;
  background: white;
  border: 1px solid var(--border);
  border-radius: 8px;
}

@media (max-width: 720px) {
  .compare { grid-template-columns: 1fr; }
}