:root {
  --bg: #f4f6f8;
  --card-bg: #ffffff;
  --primary: #1e5b8c;
  --primary-dark: #123a5c;
  --accent: #2a9d8f;
  --text: #223;
  --muted: #5a6472;
  --border: #dde3e8;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.wrap {
  max-width: 760px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
}

header h1 {
  margin-bottom: 0.25rem;
  color: var(--primary-dark);
}

header .sub {
  color: var(--muted);
  margin-top: 0;
}

form {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  margin-top: 1.5rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem 1.5rem;
}

.field {
  display: flex;
  flex-direction: column;
}

.field label {
  font-size: 0.9rem;
  margin-bottom: 0.3rem;
  color: var(--muted);
}

.field input {
  padding: 0.55rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 1rem;
}

.field input:focus {
  outline: 2px solid var(--primary);
  outline-offset: 1px;
}

.assumptions {
  margin-top: 1.25rem;
  border-top: 1px solid var(--border);
  padding-top: 1rem;
}

.assumptions summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--primary-dark);
  margin-bottom: 0.75rem;
}

.note {
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 0.75rem;
}

button[type="submit"] {
  margin-top: 1.5rem;
  background: var(--primary);
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 6px;
  font-size: 1rem;
  cursor: pointer;
  transition: background 0.15s ease;
}

button[type="submit"]:hover {
  background: var(--primary-dark);
}

.results {
  margin-top: 2rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
}

.results.hidden {
  display: none;
}

.result-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.card {
  background: #f8fafb;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

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

.card .value {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary-dark);
}

.card.highlight {
  background: linear-gradient(135deg, var(--primary), var(--accent));
}

.card.highlight .label,
.card.highlight .value {
  color: white;
}

.breakdown-block {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem;
  margin-bottom: 1rem;
  background: #fbfcfd;
}

.breakdown-block.hidden {
  display: none;
}

.breakdown-block h4 {
  margin-top: 0;
  color: var(--primary-dark);
}

.breakdown-block ul {
  margin: 0.5rem 0 0;
  padding-left: 1.2rem;
}

@media (max-width: 560px) {
  .grid {
    grid-template-columns: 1fr;
  }
}