:root {
  --ink: #1a1f24;
  --ink-soft: #3d4752;
  --sea: #0d4a5c;
  --sea-deep: #083542;
  --teal: #1b7a72;
  --foam: #f6f2ea;
  --paper: #fffdf8;
  --sand: #e8dfcf;
  --line: #d4cbb8;
  --coral: #c45c38;
  --sky: #d7e8e6;
  --white: #ffffff;
  --shadow: 0 12px 32px rgba(13, 74, 92, 0.08);
  --radius: 18px;
  --max: 1080px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--foam);
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  line-height: 1.65;
}

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

img,
svg {
  max-width: 100%;
}

.skip {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--sea);
  color: var(--white);
  padding: 0.6rem 1rem;
}

.skip:focus {
  left: 1rem;
  top: 1rem;
  z-index: 20;
}

.topbar {
  background: var(--sea-deep);
  color: var(--sand);
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  text-align: center;
  padding: 0.45rem 1rem;
}

.site-header {
  background: var(--paper);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 10;
}

.header-inner,
.footer-inner,
.wrap {
  width: min(var(--max), calc(100% - 2rem));
  margin: 0 auto;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 0.9rem 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--sea-deep);
}

.brand-mark {
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
}

.brand-name {
  font-family: Georgia, "Iowan Old Style", serif;
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand-tag {
  display: block;
  font-family: "Segoe UI", system-ui, sans-serif;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--coral);
}

nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.1rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

nav a {
  color: var(--ink-soft);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
}

nav a:hover,
nav a[aria-current="page"] {
  color: var(--sea);
}

nav a[aria-current="page"] {
  box-shadow: inset 0 -2px 0 var(--coral);
}

.hero {
  background:
    radial-gradient(circle at 12% 20%, rgba(27, 122, 114, 0.16), transparent 28%),
    linear-gradient(160deg, var(--sky) 0%, var(--foam) 55%, #efe6d4 100%);
  border-bottom: 1px solid var(--line);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2.5rem;
  align-items: center;
  padding: 3.5rem 0 3rem;
}

.kicker {
  margin: 0 0 0.6rem;
  color: var(--coral);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  font-family: Georgia, "Iowan Old Style", serif;
  line-height: 1.2;
  color: var(--sea-deep);
}

h1 {
  margin: 0 0 1rem;
  font-size: clamp(2.1rem, 5vw, 3.4rem);
  letter-spacing: -0.03em;
}

h2 {
  margin: 0 0 0.8rem;
  font-size: 1.85rem;
}

h3 {
  margin: 0 0 0.45rem;
  font-size: 1.2rem;
}

.lede {
  font-size: 1.15rem;
  color: var(--ink-soft);
  max-width: 38rem;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.6rem;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.15rem;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 700;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--coral);
  color: var(--white);
}

.btn-primary:hover {
  background: #a94b2d;
}

.btn-ghost {
  background: transparent;
  color: var(--sea);
  border-color: var(--sea);
}

.btn-ghost:hover {
  background: var(--white);
}

.hero-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.2rem;
}

.section {
  padding: 3.2rem 0;
}

.section-alt {
  background: var(--paper);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.grid-3,
.grid-2,
.cards {
  display: grid;
  gap: 1.2rem;
}

.grid-3,
.cards {
  grid-template-columns: repeat(3, 1fr);
}

.grid-2 {
  grid-template-columns: 1fr 1fr;
}

.card,
.step,
.callout,
.term {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.25rem 1.3rem;
}

.card p,
.step p,
.term p {
  margin: 0;
  color: var(--ink-soft);
}

.num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  margin-bottom: 0.7rem;
  border-radius: 50%;
  background: var(--sea);
  color: var(--white);
  font-weight: 800;
}

.callout {
  background: #fff7ef;
  border-color: #efd2bf;
}

.callout strong {
  color: var(--coral);
}

.figure {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem;
}

.figure figcaption {
  margin-top: 0.7rem;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.diagram {
  width: 100%;
  height: auto;
  display: block;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--paper);
  border-radius: var(--radius);
  overflow: hidden;
}

th,
td {
  text-align: left;
  padding: 0.8rem 0.95rem;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

th {
  background: var(--sea);
  color: var(--white);
  font-size: 0.92rem;
}

tr:last-child td {
  border-bottom: 0;
}

.checklist {
  list-style: none;
  padding: 0;
  margin: 0;
}

.checklist li {
  position: relative;
  padding: 0.55rem 0 0.55rem 2rem;
  border-bottom: 1px dashed var(--line);
}

.checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.85rem;
  width: 0.9rem;
  height: 0.9rem;
  border: 2px solid var(--teal);
  border-radius: 3px;
}

.page-hero {
  padding: 2.4rem 0 1.6rem;
}

.crumbs {
  margin: 0 0 0.8rem;
  color: var(--ink-soft);
  font-size: 0.9rem;
}

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

.two-col {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 1.6rem;
  align-items: start;
}

ol.plain {
  padding-left: 1.2rem;
}

ol.plain li {
  margin-bottom: 0.55rem;
}

.site-footer {
  background: var(--sea-deep);
  color: #d7e4e2;
  padding: 2rem 0;
  margin-top: 1rem;
}

.site-footer a {
  color: #f0d2c2;
}

.site-footer p {
  margin: 0.35rem 0;
}

@media (max-width: 860px) {
  .hero-grid,
  .grid-3,
  .grid-2,
  .cards,
  .two-col {
    grid-template-columns: 1fr;
  }

  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}