:root {
  --bg: #ffffff;
  --fg: #1a1c1f;
  --muted: #5c6370;
  --line: #e2e5ea;
  --card: #ffffff;
  --accent: #1f5fa8;
  --accent-fg: #ffffff;
  --error: #b3261e;
  --ok: #1b7f4f;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #15171a; --fg: #e8eaed; --muted: #9aa3ad; --line: #2b2f35;
    --card: #1b1e22; --accent: #74a8e8; --accent-fg: #10131a;
    --error: #f2b8b5; --ok: #7ee2a8;
  }
}
:root[data-theme="dark"] {
  --bg: #15171a; --fg: #e8eaed; --muted: #9aa3ad; --line: #2b2f35;
  --card: #1b1e22; --accent: #74a8e8; --accent-fg: #10131a;
  --error: #f2b8b5; --ok: #7ee2a8;
}

* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--fg);
  font: 16px/1.5 ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
.wrap { max-width: 980px; margin: 0 auto; padding: 0 16px; }
header { border-bottom: 1px solid var(--line); padding: 28px 0 20px; }
h1 { font-size: 1.5rem; margin: 0 0 4px; font-weight: 600; }
h2 { font-size: 1.1rem; margin: 0; font-weight: 600; }
.tagline { margin: 0; color: var(--muted); }
main { padding: 24px 0 8px; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 10px;
  padding: 20px; margin-bottom: 20px;
}
label { display: block; font-weight: 600; margin-bottom: 4px; }
.field { margin-bottom: 16px; }
.hint { color: var(--muted); font-size: .85rem; margin-top: 4px; }
input, select, textarea {
  width: 100%; padding: 9px 10px; font: inherit; color: var(--fg);
  background: var(--bg); border: 1px solid var(--line); border-radius: 7px;
}
textarea { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .9rem; }
input:disabled, select:disabled { opacity: .5; }
button {
  font: inherit; font-weight: 600; padding: 10px 18px; border-radius: 7px;
  border: 1px solid transparent; background: var(--accent); color: var(--accent-fg);
  cursor: pointer;
}
button:disabled { opacity: .6; cursor: default; }
button.link {
  background: none; color: var(--accent); border: none; padding: 4px 0;
  font-weight: 500; text-decoration: underline;
}
.row { display: flex; gap: 14px; align-items: center; flex-wrap: wrap; }
.row.between { justify-content: space-between; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.error { color: var(--error); font-weight: 500; }
.ok { color: var(--ok); }
code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .85em; }
.spinner {
  display: inline-block; width: 14px; height: 14px; border-radius: 50%;
  border: 2px solid var(--line); border-top-color: var(--accent);
  animation: spin 1s linear infinite; vertical-align: -2px; margin-right: 6px;
}
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) { .spinner { animation: none; } }
.pdf { width: 100%; height: min(88vh, 900px); border: 1px solid var(--line); border-radius: 8px; background: var(--bg); }
.downloads { list-style: none; padding: 0; margin: 14px 0 0; }
.downloads li { margin: 4px 0; }
footer { padding: 20px 0 40px; border-top: 1px solid var(--line); margin-top: 20px; }
footer a { color: var(--accent); }
#plot { width: 100%; min-height: 720px; }
.controls { display: flex; gap: 20px; align-items: flex-end; flex-wrap: wrap; margin-bottom: 12px; }
.controls label { font-weight: 500; }
.controls .inline { display: flex; gap: 6px; align-items: center; }
.controls input[type="number"] { width: 110px; }
.controls input[type="checkbox"] { width: auto; }