/* Core visual identity: "cool cousin" of Arecibo C3 */
:root {
  --primary: #1976d2;         /* science-blue */
  --accent: #26c6da;          /* cyan */
  --bg-light: #f4f9fc;        /* pale blue background */
  --text-dark: #1e1e1e;
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  --border-radius: 12px;
  --font: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
  margin: 0;
  font-family: var(--font);
  background-color: var(--bg-light);
  color: var(--text-dark);
  line-height: 1.6;
}

header {
  background: var(--primary);
  color: white;
  text-align: center;
  padding: 2em 1em 1em;
  box-shadow: var(--shadow);
}

header h1 {
  margin: 0;
  font-size: 2rem;
}

header .subtitle {
  font-size: 1rem;
  opacity: 0.9;
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 2em;
}

.upload-section,
.selector-section {
  background: white;
  border-radius: var(--border-radius);
  padding: 1.5em;
  box-shadow: var(--shadow);
  margin-bottom: 2em;
}

.upload-label {
  display: block;
  margin-bottom: 0.5em;
  font-weight: bold;
}

input[type="file"],
select {
  font-size: 1rem;
  padding: 0.5em;
  border: 1px solid #ccc;
  border-radius: 6px;
  width: 100%;
  box-sizing: border-box;
}

pre#output {
  background: #eef3f7;
  padding: 1em;
  border-radius: 6px;
  margin-top: 1em;
  font-size: 0.9rem;
  overflow-x: auto;
}

.plot-section {
  display: flex;
  flex-direction: column;
  gap: 2em;
}

.plot-container {
  background: white;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  padding: 1em;
  min-height: 400px;
}

footer {
  text-align: center;
  font-size: 0.85rem;
  color: #666;
  padding: 2em 1em;
  margin-top: 4em;
}