:root {
  color-scheme: dark;
  --bg: #070b16;
  --bg-soft: #111827;
  --card: #172238;
  --card-2: #1f2b45;
  --border: #30415f;
  --text: #f8fafc;
  --muted: #a8c0ff;
  --accent: #68a4ff;
  --accent-2: #86efdc;
  --danger: #ef4444;
  --warning: #facc15;
  --shadow: rgba(0, 0, 0, 0.35);
}

body.light-theme {
  color-scheme: light;
  --bg: #eff6ff;
  --bg-soft: #ffffff;
  --card: #ffffff;
  --card-2: #eaf2ff;
  --border: #b9c7dc;
  --text: #111827;
  --muted: #315584;
  --accent: #2563eb;
  --accent-2: #0f766e;
  --shadow: rgba(30, 64, 175, 0.12);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background:
    radial-gradient(circle at top left, rgba(104, 164, 255, 0.18), transparent 28rem),
    radial-gradient(circle at top right, rgba(134, 239, 220, 0.10), transparent 26rem),
    var(--bg);
  color: var(--text);
  font-family: Inter, Arial, Helvetica, sans-serif;
  min-height: 100vh;
}

.app-header {
  padding: 32px 24px 18px;
  text-align: center;
}

.app-header h1 {
  margin: 0;
  font-size: clamp(26px, 4vw, 42px);
  letter-spacing: -0.03em;
  text-shadow: 0 3px 16px rgba(0,0,0,.22);
}

.app-header p {
  margin: 10px auto 0;
  max-width: 880px;
  color: var(--muted);
  font-size: 16px;
}

.app-shell {
  width: min(1240px, calc(100% - 32px));
  margin: 0 auto 40px;
  display: grid;
  gap: 22px;
}

.card {
  background: linear-gradient(180deg, var(--card), var(--bg-soft));
  border: 1px solid var(--border);
  border-radius: 30px;
  box-shadow: 0 18px 60px var(--shadow);
  padding: 24px;
}

.preset-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
}

.preset-row label,
.field label,
.section-title {
  color: var(--muted);
  font-weight: 700;
}

.preset-highlight select {
  min-width: min(100%, 390px);
  color: #fff;
  background: linear-gradient(135deg, #2563eb, #0891b2);
  border: 1px solid rgba(255,255,255,.35);
  font-weight: 800;
}

.preset-highlight select option {
  background: #1f2b45;
  color: #fff;
}

body.light-theme .preset-highlight select option {
  background: #ffffff;
  color: #111827;
}

.manual-badge {
  display: inline-flex;
  align-items: center;
  padding: 7px 10px;
  border-radius: 999px;
  color: #111827;
  background: var(--warning);
  font-size: 13px;
  font-weight: 800;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.full-width { margin-bottom: 18px; }

textarea,
input,
select {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 18px;
  color: var(--text);
  background: var(--card-2);
  padding: 13px 16px;
  font: inherit;
  font-weight: 650;
  outline: none;
  transition: border-color .2s, box-shadow .2s, transform .2s;
}

textarea:focus,
input:focus,
select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px rgba(104, 164, 255, .18);
}

textarea {
  resize: vertical;
  min-height: 74px;
  line-height: 1.55;
}

.formula-block {
  border: 1px solid var(--border);
  background: rgba(104,164,255,.08);
  color: var(--muted);
  border-radius: 22px;
  padding: 12px 16px;
  margin: 12px 0 24px;
  overflow-x: auto;
}

.section-title {
  margin: 22px 0 12px;
  font-size: 22px;
  color: var(--text);
}

.grid-4,
.grid-3 {
  display: grid;
  gap: 16px;
}

.grid-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.actions {
  display: grid;
  grid-template-columns: repeat(4, minmax(140px, 1fr)) auto;
  align-items: center;
  gap: 14px;
  margin-top: 24px;
}

button {
  border: 0;
  border-radius: 20px;
  padding: 14px 18px;
  color: #f8fafc;
  font: inherit;
  font-weight: 900;
  cursor: pointer;
  transition: transform .15s, filter .15s, opacity .15s;
}

button:hover:not(:disabled) { transform: translateY(-1px); filter: brightness(1.07); }
button:disabled { opacity: .45; cursor: not-allowed; }

.primary { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #05101f; }
.secondary { background: #263653; }
.danger { background: linear-gradient(135deg, #ef4444, #b91c1c); }

.theme-toggle {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  color: var(--text);
  white-space: nowrap;
}

.result-card .status {
  color: var(--text);
  font-weight: 900;
  font-size: 22px;
  margin-bottom: 18px;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.metrics > div {
  border: 1px solid var(--border);
  border-radius: 22px;
  background: var(--card-2);
  padding: 18px;
  min-height: 92px;
}

.metrics span {
  display: block;
  color: var(--muted);
  margin-bottom: 12px;
}

.metrics strong {
  display: block;
  font-size: 24px;
  word-break: break-word;
}

.diagnostics {
  border: 1px solid var(--border);
  border-radius: 22px;
  margin-top: 18px;
  padding: 16px 18px;
  color: var(--muted);
  line-height: 1.6;
  background: rgba(104,164,255,.07);
}

.warning-line { color: var(--warning); font-weight: 800; }

.plot-card { overflow: hidden; }

.plot-header {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: baseline;
  margin-bottom: 10px;
}

.plot-header h2 {
  margin: 0;
  font-size: 24px;
}

.plot-header span,
.plot-note {
  color: var(--muted);
}

.plot-note {
  margin: 0 0 10px;
  font-size: 14px;
}

.plot {
  width: 100%;
  height: 560px;
  border-radius: 24px;
  overflow: hidden;
  background: var(--bg-soft);
}

.plot.small { height: 430px; }

.plot-fallback {
  display: grid;
  place-items: center;
  height: 100%;
  padding: 24px;
  color: var(--muted);
  text-align: center;
}

@media (max-width: 900px) {
  .grid-4,
  .grid-3,
  .metrics,
  .actions {
    grid-template-columns: 1fr 1fr;
  }

  .actions .theme-toggle { grid-column: 1 / -1; }
}

@media (max-width: 620px) {
  .grid-4,
  .grid-3,
  .metrics,
  .actions {
    grid-template-columns: 1fr;
  }

  .card { border-radius: 22px; padding: 16px; }
  .plot { height: 420px; }
  .plot.small { height: 360px; }
}