/* ---------- Base / layout ---------- */
:root {
  --color-bg: #f5f2ec;
  --color-surface: #ffffff;
  --color-border: #ddd4c4;
  --color-text: #2e2a24;
  --color-muted: #6b6356;
  --color-accent: #8a5a2b;
  --color-accent-dark: #6e4621;
  --color-accent-contrast: #fff8ef;
  --color-warn-bg: #fff6e0;
  --color-warn-border: #e5c36b;
  --radius: 8px;
  --gap: 1rem;
  font-size: 16px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", Helvetica, Arial, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.45;
}

.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.app-header {
  background: var(--color-accent-dark);
  color: var(--color-accent-contrast);
  padding: 1.25rem 1.5rem 1rem;
}

.app-header h1 {
  margin: 0;
  font-size: 1.6rem;
  letter-spacing: 0.02em;
}

.app-header .subtitle {
  margin: 0.15rem 0 0;
  font-size: 0.95rem;
  opacity: 0.85;
}

.app-body {
  flex: 1;
  display: flex;
  align-items: stretch;
  min-height: 0;
}

.app-nav {
  flex: 0 0 220px;
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  padding: 1rem 0.75rem;
}

.app-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.nav-link {
  display: block;
  padding: 0.65rem 0.75rem;
  border-radius: var(--radius);
  color: var(--color-text);
  text-decoration: none;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  background: none;
  width: 100%;
  text-align: left;
  font-size: 0.95rem;
}

.nav-link:hover {
  background: var(--color-bg);
}

.nav-link.active {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent-dark);
}

.nav-link.disabled {
  color: var(--color-muted);
  cursor: default;
}

.nav-link.disabled:hover {
  background: none;
}

.nav-badge {
  display: inline-block;
  margin-left: 0.4rem;
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 0.1rem 0.4rem;
  border-radius: 999px;
  background: var(--color-warn-border);
  color: #4a3a10;
  vertical-align: middle;
}

.app-main {
  flex: 1;
  padding: 1.5rem 2rem 2.5rem;
  overflow-y: auto;
  min-width: 0;
}

.app-footer {
  padding: 0.75rem 1.5rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-muted);
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
}

/* ---------- Tool content ---------- */
.tool h2 {
  margin-top: 0;
}

.tool-description {
  color: var(--color-muted);
  max-width: 68ch;
  margin-bottom: 1.5rem;
}

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

.panel h3 {
  margin-top: 0;
  font-size: 1.05rem;
}

.field-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem 1.5rem;
}

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

.field label {
  font-weight: 600;
  font-size: 0.9rem;
}

.field .hint {
  font-size: 0.78rem;
  color: var(--color-muted);
  font-weight: 400;
}

select, input[type="number"], input[type="text"] {
  font-size: 0.95rem;
  padding: 0.45rem 0.55rem;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  background: #fff;
  color: var(--color-text);
}

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

details.advanced {
  margin-top: 1rem;
}

details.advanced summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--color-accent-dark);
}

details.advanced .field-grid {
  margin-top: 0.75rem;
}

/* ---------- Results ---------- */
.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1rem;
}

.result-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
}

.result-card .label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-muted);
  margin-bottom: 0.25rem;
}

.result-card .value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-accent-dark);
}

.result-card .value small {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-muted);
}

.result-card.highlight {
  border-color: var(--color-accent);
  background: #fbf1e3;
}

table.detail-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 0.5rem;
  font-size: 0.9rem;
}

table.detail-table th, table.detail-table td {
  text-align: left;
  padding: 0.45rem 0.6rem;
  border-bottom: 1px solid var(--color-border);
}

table.detail-table th {
  color: var(--color-muted);
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
}

.warning-banner {
  background: var(--color-warn-bg);
  border: 1px solid var(--color-warn-border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  font-size: 0.88rem;
  margin-bottom: 1rem;
}

.under-construction {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--color-muted);
}

.under-construction .icon {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

@media (max-width: 760px) {
  .app-body { flex-direction: column; }
  .app-nav { flex: none; border-right: none; border-bottom: 1px solid var(--color-border); }
  .app-nav ul { flex-direction: row; flex-wrap: wrap; }
}