:root {
  color-scheme: light;
  --bg: #f3f7ff;
  --card: #ffffff;
  --text: #162033;
  --muted: #55617a;
  --line: #d8e1f2;
  --accent: #2555d6;
  --accent-strong: #1a45b6;
  --danger: #b42318;
  --shadow: 0 10px 24px rgba(20, 44, 111, 0.09);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: radial-gradient(circle at top right, #e7f0ff, var(--bg) 42%);
  color: var(--text);
  line-height: 1.5;
}

a {
  color: var(--accent);
}

a:hover,
a:focus-visible {
  color: var(--accent-strong);
}

.page-header,
.page-footer {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.5rem 1rem;
}

.page-header h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.5rem, 2.6vw, 2.25rem);
}

.page-header p {
  margin: 0.4rem 0;
  color: var(--muted);
}

.links {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.layout {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1rem 1.5rem;
  display: grid;
  gap: 1rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 1rem;
}

.card h2,
.card h3 {
  margin: 0 0 0.75rem;
}

.input-grid {
  display: grid;
  gap: 0.9rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.field {
  display: grid;
  gap: 0.35rem;
}

label {
  font-weight: 600;
  font-size: 0.92rem;
}

input,
select,
button {
  font: inherit;
}

input,
select {
  width: 100%;
  border: 1px solid #bcc9e4;
  border-radius: 10px;
  padding: 0.6rem 0.7rem;
  background: #fff;
  color: var(--text);
}

input:focus-visible,
select:focus-visible,
button:focus-visible {
  outline: 3px solid rgba(37, 85, 214, 0.2);
  outline-offset: 1px;
  border-color: var(--accent);
}

.actions {
  display: flex;
  gap: 0.7rem;
  margin-top: 1rem;
  flex-wrap: wrap;
}

button {
  border: 1px solid transparent;
  border-radius: 10px;
  padding: 0.6rem 0.95rem;
  font-weight: 600;
  cursor: pointer;
  background: var(--accent);
  color: #fff;
}

button:hover {
  background: var(--accent-strong);
}

button.secondary {
  background: #eef3ff;
  color: #16326f;
  border-color: #cdd9f6;
}

button.secondary:hover {
  background: #e2ebff;
}

.error {
  min-height: 1.2rem;
  margin: 0.7rem 0 0;
  color: var(--danger);
  font-weight: 600;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.8rem;
  margin: 0 0 1rem;
}

.metrics div {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.75rem;
  background: #fbfcff;
}

.metrics dt {
  margin: 0;
  font-size: 0.9rem;
  color: var(--muted);
}

.metrics dd {
  margin: 0.3rem 0 0;
  font-size: 1.16rem;
  font-weight: 700;
}

.warnings {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--muted);
}

.provenance {
  margin-top: 0.9rem;
  color: var(--muted);
}

.chart-figure {
  margin: 0;
}

#costChart {
  width: 100%;
  height: auto;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: #fcfdff;
}

.chart-bg {
  fill: #f7faff;
}

.grid-line {
  stroke: #dbe6fb;
  stroke-width: 1;
}

.axis-line {
  stroke: #8ea3d6;
  stroke-width: 1.3;
}

.line-path {
  fill: none;
  stroke: #2555d6;
  stroke-width: 2.5;
}

.point-dot {
  fill: #2555d6;
}

.axis-label {
  fill: #495978;
  font-size: 11.5px;
}

.axis-title {
  fill: #223862;
  font-size: 12px;
  font-weight: 600;
}

.chart-figure figcaption {
  margin-top: 0.5rem;
  color: var(--muted);
}

.page-footer p {
  margin: 0;
  color: var(--muted);
  border-top: 1px solid var(--line);
  padding-top: 1rem;
}

@media (max-width: 700px) {
  .card {
    padding: 0.85rem;
  }

  .actions {
    width: 100%;
  }

  button {
    flex: 1 1 220px;
  }
}