:root {
  --bg: #ffffff;
  --panel: #f7f8fa;
  --line: #e3e6ea;
  --ink: #14171a;
  --ink-soft: #5b6470;
  --accent: #0b6bcb;
  --accent-soft: #eaf3fd;
  --good: #0f7a4a;
  --warn: #a1440d;
  --radius: 10px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
}

.wrap {
  max-width: 1120px;
  margin: 0 auto;
  padding: 24px 20px 64px;
}

header.top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 18px;
}

h1 {
  font-size: 28px;
  line-height: 1.2;
  margin: 0;
  letter-spacing: -0.01em;
}

.tagline {
  margin: 4px 0 0;
  color: var(--ink-soft);
  font-size: 15px;
}

.badge {
  font-size: 13px;
  color: var(--ink-soft);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 10px;
  white-space: nowrap;
}

.grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 380px);
  gap: 20px;
  align-items: start;
}

.card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  padding: 18px;
}

.card.results {
  background: var(--panel);
  position: sticky;
  top: 16px;
}

.card h2 {
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-soft);
  margin: 0 0 14px;
}

.field { margin-bottom: 14px; }

label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-soft);
  margin-bottom: 5px;
}

input[type="number"], input[type="text"], select {
  width: 100%;
  font-size: 16px;
  padding: 10px 11px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font-family: inherit;
}

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

.row2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.chips {
  display: flex;
  gap: 6px;
  margin-top: 7px;
  flex-wrap: wrap;
}

.chip {
  font: inherit;
  font-size: 13px;
  padding: 4px 10px;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 999px;
  cursor: pointer;
  color: var(--ink-soft);
}

.chip:hover { background: var(--accent-soft); color: var(--accent); }

details.adv {
  margin-top: 6px;
  border-top: 1px solid var(--line);
  padding-top: 12px;
}

details.adv summary {
  cursor: pointer;
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-soft);
}

.hint {
  font-size: 12px;
  color: var(--ink-soft);
  margin-top: 4px;
}

.result-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 10px;
  padding: 9px 0;
  border-bottom: 1px dashed var(--line);
}

.result-row:last-of-type { border-bottom: none; }

.result-row .k { font-size: 13px; color: var(--ink-soft); }

.result-row .v {
  font-size: 17px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  overflow-wrap: anywhere;
  text-align: right;
}

.big {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 14px;
  margin-bottom: 12px;
}

.big .k { font-size: 12px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--ink-soft); }

.big .v {
  font-size: 30px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  overflow-wrap: anywhere;
}

.note-risk {
  font-size: 13px;
  color: var(--ink-soft);
  margin: 10px 0 0;
}

.btn {
  width: 100%;
  margin-top: 14px;
  font: inherit;
  font-size: 15px;
  font-weight: 600;
  padding: 11px 12px;
  border-radius: 8px;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  cursor: pointer;
}

.btn.secondary {
  background: #fff;
  color: var(--accent);
}

.btn:hover { filter: brightness(0.97); }

.error {
  margin-top: 10px;
  color: var(--warn);
  font-size: 13px;
  display: none;
}

.error.on { display: block; }

section.doc {
  margin-top: 34px;
}

section.doc h2 {
  font-size: 20px;
  margin: 0 0 10px;
}

section.doc h3 {
  font-size: 16px;
  margin: 20px 0 6px;
}

section.doc p, section.doc li {
  color: #2b3138;
  font-size: 15px;
}

code, .formula {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 2px 6px;
  font-size: 14px;
}

.formula {
  display: block;
  padding: 12px;
  overflow-x: auto;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

table.src {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

table.src th, table.src td {
  text-align: left;
  border-bottom: 1px solid var(--line);
  padding: 8px 6px;
  vertical-align: top;
}

details.faq { border-bottom: 1px solid var(--line); padding: 10px 0; }

details.faq summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 15px;
}

details.faq p { margin: 8px 0 0; font-size: 15px; color: #2b3138; }

footer.foot {
  margin-top: 40px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--ink-soft);
}

nav.footnav {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  margin: 0 0 10px;
}

nav.footnav a {
  color: var(--accent);
  text-decoration: none;
  font-size: 13px;
  font-weight: 600;
}

nav.footnav a:hover,
nav.footnav a:focus { text-decoration: underline; }

a.badge {
  text-decoration: none;
  color: var(--ink-soft);
}

a.badge:hover {
  border-color: var(--accent);
  color: var(--accent);
}

section.doc a {
  color: var(--accent);
  overflow-wrap: anywhere;
}

@media (max-width: 900px) {
  .grid { grid-template-columns: 1fr; }
  .card.results { position: static; }
}

@media (max-width: 480px) {
  .wrap { padding: 16px 14px 48px; }
  h1 { font-size: 23px; }
  .row2 { grid-template-columns: 1fr; }
  .big .v { font-size: 26px; }
}