:root {
  --page: #eef2f5;
  --panel: #ffffff;
  --line: #d8e0e6;
  --ink: #111820;
  --muted: #64717c;
  --action: #1c6ca8;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.55;
}

.page {
  max-width: 860px;
  margin: 0 auto;
  padding: 32px 18px 48px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-size: 22px;
  font-weight: 900;
}

.brand img {
  width: 32px;
  height: 32px;
}

.guide-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 7px 14px;
  margin-top: 22px;
}

.guide-nav a {
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

.guide-nav a:hover,
.guide-nav a[aria-current="page"] {
  color: var(--action);
  text-decoration: underline;
  text-underline-offset: 3px;
}

main {
  margin-top: 28px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

h1 {
  margin: 0 0 12px;
  font-size: clamp(30px, 5vw, 48px);
  line-height: 1.05;
}

h2 {
  margin: 28px 0 10px;
  font-size: 22px;
}

.lead {
  font-size: 18px;
}

p,
li {
  color: #2f3a43;
}

ol,
ul {
  margin: 10px 0 0;
  padding-left: 24px;
}

li + li {
  margin-top: 6px;
}

a {
  color: var(--action);
  font-weight: 700;
}

.cta {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  margin-top: 12px;
  padding: 0 16px;
  border-radius: 7px;
  background: var(--action);
  color: #ffffff;
  text-decoration: none;
}

.note {
  color: var(--muted);
  font-size: 14px;
}

.source-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
}

.letter-search {
  margin: 24px 0;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f7fafc;
}

.letter-search label {
  display: block;
  margin-bottom: 8px;
  color: var(--ink);
  font-weight: 800;
}

.letter-search-row {
  display: flex;
  gap: 8px;
}

.letter-search input {
  min-width: 0;
  flex: 1;
  padding: 11px 12px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #ffffff;
  color: var(--ink);
  font: inherit;
  text-transform: uppercase;
}

.letter-search button {
  padding: 0 16px;
  border: 0;
  border-radius: 6px;
  background: var(--action);
  color: #ffffff;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}

.form-help {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.table-scroll {
  overflow-x: auto;
  margin-top: 14px;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: #ffffff;
  font-variant-numeric: tabular-nums;
}

caption {
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 13px;
  text-align: left;
}

th,
td {
  padding: 7px 10px;
  border: 1px solid var(--line);
  text-align: left;
}

th {
  background: #f1f5f7;
  color: var(--ink);
}

.related {
  margin-top: 32px;
  padding-top: 2px;
  border-top: 1px solid var(--line);
}

@media (max-width: 640px) {
  .page {
    padding-top: 18px;
  }

  main {
    padding: 20px;
  }

  .letter-search-row {
    align-items: stretch;
    flex-direction: column;
  }

  .letter-search button {
    min-height: 44px;
  }
}