:root {
  --bg: #14161a;
  --surface: #1c1f25;
  --surface-raised: #242830;
  --border: #33373f;
  --text: #eef1f4;
  --text-muted: #8b93a0;
  --accent: #2dd4bf;
  --accent-dim: #2a8577;
  --ok: #7fa37a;
  --err: #c4604a;
  --serif: Charter, "Iowan Old Style", "Palatino Linotype", Georgia, ui-serif, serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --sans: -apple-system, "Segoe UI", system-ui, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 3rem 1.5rem 5rem;
  background: var(--bg);
  background-image:
    radial-gradient(ellipse 900px 500px at 50% -10%, rgba(45, 212, 191, 0.07), transparent);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.5;
  min-height: 100vh;
}

.wrap {
  max-width: 640px;
  margin: 0 auto;
}

.eyebrow {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.6rem;
}

h1 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: 2.1rem;
  line-height: 1.15;
  margin: 0 0 0.5rem;
  color: var(--text);
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin: 0 0 2.5rem;
  max-width: 46ch;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.75rem;
}

.pair-card + .pair-card {
  margin-top: 1rem;
}

form { display: block; }

.duo {
  position: relative;
  margin-bottom: 1.25rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
}

.duo:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.remove-duo {
  position: absolute;
  top: -0.4rem;
  right: -0.4rem;
  width: 1.5rem;
  height: 1.5rem;
  line-height: 1;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--surface-raised);
  color: var(--text-muted);
  font-size: 1rem;
  cursor: pointer;
  z-index: 1;
}

.duo:first-child .remove-duo { display: none; }
.remove-duo:hover { color: var(--err); border-color: var(--err); }

.add-duo {
  display: block;
  width: 100%;
  background: transparent;
  border: 1px dashed var(--border);
  color: var(--text-muted);
  padding: 0.6rem 1rem;
  border-radius: 7px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: border-color 0.15s ease, color 0.15s ease;
}

.add-duo:hover { color: var(--text); border-color: var(--accent-dim); }

.dropzones {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

@media (max-width: 520px) {
  .dropzones { grid-template-columns: 1fr; }
}

.dropzone {
  position: relative;
  border: 1px dashed var(--border);
  border-radius: 8px;
  padding: 1.25rem 1rem;
  text-align: center;
  transition: border-color 0.15s ease, background 0.15s ease;
  background: var(--surface-raised);
}

.dropzone:has(input:focus-visible) {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.dropzone.has-file {
  border-color: var(--accent-dim);
  border-style: solid;
}

.dropzone label.tag {
  display: block;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.dropzone .hint {
  color: var(--text-muted);
  font-size: 0.8rem;
}

.dropzone .filename {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--text);
  word-break: break-all;
  margin-top: 0.35rem;
  display: none;
}

.dropzone input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  width: 100%;
  height: 100%;
}

button.run {
  width: 100%;
  margin-top: 1.5rem;
  background: var(--accent);
  color: #06211d;
  border: none;
  padding: 0.75rem 1rem;
  border-radius: 7px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s ease;
}

button.run:hover { background: #5eead4; }
button.run:focus-visible { outline: 2px solid var(--text); outline-offset: 2px; }

.error-banner {
  background: rgba(196, 96, 74, 0.12);
  border: 1px solid rgba(196, 96, 74, 0.4);
  color: #e2a795;
  padding: 0.7rem 0.9rem;
  border-radius: 7px;
  font-size: 0.85rem;
  margin-bottom: 1.25rem;
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.35rem 0.7rem;
  border-radius: 5px;
  margin-bottom: 1.25rem;
}

.status.ok { background: rgba(127, 163, 122, 0.14); color: var(--ok); }
.status.err { background: rgba(196, 96, 74, 0.14); color: var(--err); }

.warning-banner {
  background: rgba(45, 212, 191, 0.1);
  border: 1px solid rgba(45, 212, 191, 0.35);
  color: var(--accent);
  padding: 0.7rem 0.9rem;
  border-radius: 7px;
  font-size: 0.85rem;
  margin-bottom: 1.25rem;
}

pre.log {
  background: #0e1015;
  border: 1px solid var(--border);
  border-radius: 7px;
  padding: 1rem;
  font-family: var(--mono);
  font-size: 0.76rem;
  color: #b6c0c8;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
  max-height: 360px;
  overflow-y: auto;
}

.actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.25rem;
  flex-wrap: wrap;
}

.btn-download,
.btn-secondary {
  display: inline-block;
  text-decoration: none;
  padding: 0.65rem 1.1rem;
  border-radius: 7px;
  font-size: 0.88rem;
  font-weight: 600;
}

.btn-download {
  background: var(--accent);
  color: #06211d;
}
.btn-download:hover { background: #5eead4; }

.btn-secondary {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
}
.btn-secondary:hover { color: var(--text); border-color: var(--accent-dim); }

.footnote {
  margin-top: 2rem;
  color: var(--text-muted);
  font-size: 0.78rem;
  line-height: 1.6;
}

.footnote code {
  font-family: var(--mono);
  background: var(--surface-raised);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
}

.version {
  margin-top: 0.75rem;
  color: var(--text-muted);
  font-family: var(--mono);
  font-size: 0.7rem;
  opacity: 0.6;
}