:root {
  --bg: #0f1115;
  --panel: #171a21;
  --border: #2a2e38;
  --text: #e8eaf0;
  --muted: #9aa1ae;
  --accent: #ff7a1a;
  --accent-dim: #ff7a1a33;
  --good: #3ddc84;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f5f6f8;
    --panel: #ffffff;
    --border: #dde1e8;
    --text: #1a1d24;
    --muted: #5b6270;
    --accent: #d9600a;
    --accent-dim: #d9600a22;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

header {
  padding: 2rem 1.5rem 1rem;
  max-width: 1100px;
  margin: 0 auto;
}

h1 { margin: 0 0 0.25rem; font-size: 1.6rem; }
.subtitle { color: var(--muted); margin: 0; max-width: 60ch; }

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem 3rem;
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 1.5rem;
  align-items: start;
}

@media (max-width: 800px) {
  main { grid-template-columns: 1fr; }
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem 1.5rem 1.5rem;
}

.panel h2 { margin-top: 0; font-size: 1.1rem; }
.panel h3 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
  margin: 1.25rem 0 0.5rem;
  border-top: 1px solid var(--border);
  padding-top: 1rem;
}
.panel h3:first-of-type { border-top: none; padding-top: 0; }

.field {
  margin-bottom: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.field label {
  font-size: 0.85rem;
  color: var(--muted);
}

.field .unit { color: var(--muted); font-weight: normal; }

input, select {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.5rem 0.6rem;
  border-radius: 6px;
  font-size: 0.95rem;
}

input:focus, select:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

button[type="submit"] {
  margin-top: 1rem;
  width: 100%;
  padding: 0.7rem;
  background: var(--accent);
  color: #17120a;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
}

button[type="submit"]:hover { filter: brightness(1.08); }

.results .headline {
  display: flex;
  align-items: baseline;
  gap: 0.4rem;
  margin: 0.5rem 0 0.25rem;
}

#power-value {
  font-size: 3.2rem;
  font-weight: 700;
  color: var(--accent);
}

.power-unit { font-size: 1.4rem; color: var(--muted); }
.power-note { color: var(--muted); margin-top: 0; }

table.breakdown {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0 1.5rem;
  font-size: 0.9rem;
}

table.breakdown th, table.breakdown td {
  text-align: right;
  padding: 0.4rem 0.5rem;
  border-bottom: 1px solid var(--border);
}

table.breakdown th:first-child, table.breakdown td:first-child { text-align: left; }
table.breakdown tfoot td { font-weight: 700; border-bottom: none; }

.graph-controls {
  display: flex;
  gap: 1.5rem;
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 0.75rem;
}

.graph-controls label { display: flex; align-items: center; gap: 0.4rem; cursor: pointer; }

canvas#chart {
  width: 100%;
  height: auto;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
}

.formula-note {
  color: var(--muted);
  font-size: 0.88rem;
  max-width: 70ch;
}

.formula-note code {
  background: var(--bg);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  border: 1px solid var(--border);
}

.formula-steps {
  font-size: 0.85rem;
  color: var(--muted);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  white-space: pre-wrap;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  line-height: 1.6;
}

footer {
  text-align: center;
  color: var(--muted);
  font-size: 0.8rem;
  padding: 1.5rem;
}