:root {
  --seo-paper: #f3efe5;
  --seo-paper-deep: #e6e0d2;
  --seo-white: #fffdf8;
  --seo-ink: #15171b;
  --seo-muted: #555b59;
  --seo-coral: #ff654a;
  --seo-coral-text: #a83224;
  --seo-blue: #3448e5;
  --seo-lime: #dbff65;
  --seo-line: rgba(21, 23, 27, 0.2);
}

html {
  color-scheme: light;
  scroll-behavior: smooth;
}

body {
  min-width: 0;
  margin: 0;
  background:
    linear-gradient(rgba(21, 23, 27, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(21, 23, 27, 0.035) 1px, transparent 1px),
    var(--seo-paper);
  background-size: 44px 44px;
  color: var(--seo-ink);
  font-family: Inter, "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  line-height: 1.75;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

a {
  color: inherit;
}

.seo-skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 20;
  padding: 10px 14px;
  background: var(--seo-ink);
  color: var(--seo-white);
  transform: translateY(-150%);
}

.seo-skip-link:focus {
  transform: translateY(0);
}

.seo-site-header {
  width: min(1080px, calc(100% - 40px));
  min-height: 76px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid var(--seo-line);
}

.seo-brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  font-size: 0.96rem;
  font-weight: 950;
  letter-spacing: -0.02em;
  text-decoration: none;
}

.seo-brand-face {
  width: 34px;
  height: 34px;
  position: relative;
  display: inline-block;
  border: 2px solid var(--seo-ink);
  border-radius: 50%;
  background: var(--seo-white);
  box-shadow: 3px 3px 0 var(--seo-blue);
}

.seo-brand-face i {
  width: 3px;
  height: 7px;
  position: absolute;
  top: 9px;
  border-radius: 4px;
  background: var(--seo-blue);
}

.seo-brand-face i:first-child { left: 9px; }
.seo-brand-face i:nth-child(2) { right: 9px; }

.seo-brand-face b {
  width: 13px;
  height: 7px;
  position: absolute;
  right: 8px;
  bottom: 7px;
  border: 2px solid var(--seo-blue);
  border-top: 0;
  border-radius: 0 0 12px 12px;
}

.seo-site-header nav {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.76rem;
  font-weight: 850;
}

.seo-site-header nav a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  text-underline-offset: 4px;
}

.seo-site-header .seo-header-cta {
  padding: 0 16px;
  border: 2px solid var(--seo-ink);
  background: var(--seo-coral);
  box-shadow: 3px 3px 0 var(--seo-ink);
  text-decoration: none;
}

main {
  width: min(980px, calc(100% - 40px));
  margin: 0 auto;
}

.seo-breadcrumbs {
  margin: 28px 0 0;
  color: var(--seo-muted);
  font-size: 0.72rem;
  font-weight: 750;
}

.seo-breadcrumbs ol {
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
}

.seo-breadcrumbs li + li::before {
  margin-right: 8px;
  content: "/";
}

.seo-breadcrumbs a { text-underline-offset: 3px; }

.seo-article {
  margin-top: 24px;
  border: 2px solid var(--seo-ink);
  background: var(--seo-white);
  box-shadow: 10px 10px 0 var(--seo-blue);
}

.seo-hero {
  padding: clamp(42px, 8vw, 82px) clamp(24px, 7vw, 72px) clamp(38px, 6vw, 64px);
  border-bottom: 2px solid var(--seo-ink);
  background:
    linear-gradient(135deg, transparent 78%, rgba(219, 255, 101, 0.82) 78%),
    var(--seo-paper);
}

.seo-eyebrow,
.seo-related > p,
.seo-primary-cta > p {
  margin: 0;
  color: var(--seo-coral-text);
  font-size: 0.72rem;
  font-weight: 950;
  letter-spacing: 0.14em;
}

.seo-hero h1 {
  max-width: 820px;
  margin: 20px 0 0;
  font-size: clamp(2.25rem, 6.3vw, 4.6rem);
  font-weight: 950;
  letter-spacing: -0.065em;
  line-height: 1.08;
}

.seo-lead {
  max-width: 760px;
  margin: 30px 0 0;
  color: #3f4543;
  font-size: clamp(1rem, 2vw, 1.17rem);
  font-weight: 700;
  line-height: 1.95;
}

.seo-updated {
  margin: 26px 0 0;
  color: var(--seo-muted);
  font-size: 0.7rem;
  font-weight: 700;
}

.seo-answer-box {
  margin: clamp(30px, 5vw, 54px) clamp(20px, 6vw, 64px) 0;
  padding: clamp(24px, 4vw, 38px);
  border: 2px solid var(--seo-ink);
  background: var(--seo-ink);
  box-shadow: 7px 7px 0 var(--seo-lime);
  color: var(--seo-white);
}

.seo-answer-box > span {
  color: var(--seo-lime);
  font-size: 0.72rem;
  font-weight: 950;
  letter-spacing: 0.12em;
}

.seo-answer-box h2 {
  margin: 14px 0 0;
  font-size: clamp(1.15rem, 3vw, 1.55rem);
  letter-spacing: -0.025em;
  line-height: 1.55;
}

.seo-answer-box ul {
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
  list-style: none;
}

.seo-answer-box li {
  padding-left: 22px;
  position: relative;
  color: rgba(255, 255, 255, 0.78);
  font-size: 0.86rem;
  font-weight: 700;
}

.seo-answer-box li::before {
  position: absolute;
  left: 0;
  content: "●";
  color: var(--seo-coral);
}

.seo-article-section,
.seo-comparison {
  margin: 0 clamp(20px, 6vw, 64px);
  padding: clamp(48px, 8vw, 82px) 0;
  border-bottom: 1px solid var(--seo-line);
}

.seo-article-section h2,
.seo-comparison h2,
.seo-related h2,
.seo-primary-cta h2 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(1.7rem, 4.4vw, 2.65rem);
  font-weight: 950;
  letter-spacing: -0.045em;
  line-height: 1.25;
}

.seo-article-section > p,
.seo-comparison > p {
  max-width: 760px;
  margin: 24px 0 0;
  color: #3f4543;
  font-size: 1rem;
  font-weight: 650;
  line-height: 2;
}

.seo-content-list {
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
  list-style: none;
  counter-reset: seo-step;
}

.seo-content-list li {
  min-width: 0;
  padding: 20px 22px;
  display: grid;
  gap: 7px;
  border: 1px solid var(--seo-line);
  background: var(--seo-paper);
  color: #353b39;
  font-size: 0.9rem;
}

.seo-content-list li::before {
  content: "•";
  color: var(--seo-coral-text);
  font-weight: 950;
}

.seo-content-list.is-ordered li {
  padding-left: 72px;
  position: relative;
  counter-increment: seo-step;
}

.seo-content-list.is-ordered li::before {
  width: 38px;
  height: 38px;
  position: absolute;
  top: 20px;
  left: 20px;
  display: grid;
  place-items: center;
  border: 2px solid var(--seo-ink);
  background: var(--seo-coral);
  color: var(--seo-ink);
  content: counter(seo-step);
  font-size: 0.82rem;
}

.seo-content-list strong {
  color: var(--seo-ink);
  font-size: 1rem;
  font-weight: 950;
}

.seo-content-list span { line-height: 1.75; }

.seo-example {
  margin: 34px 0 0;
  padding: clamp(23px, 4vw, 36px);
  border: 2px solid var(--seo-ink);
  background: var(--seo-blue);
  box-shadow: 7px 7px 0 var(--seo-lime);
  color: var(--seo-white);
}

.seo-example > span {
  display: block;
  color: var(--seo-lime);
  font-size: 0.7rem;
  font-weight: 950;
  letter-spacing: 0.1em;
}

.seo-example > strong {
  margin-top: 12px;
  display: block;
  font-size: clamp(1.15rem, 3vw, 1.5rem);
}

.seo-example ol {
  margin: 24px 0 0;
  padding-left: 1.4rem;
  display: grid;
  gap: 10px;
  color: rgba(255, 255, 255, 0.86);
  font-size: 0.9rem;
  font-weight: 700;
}

.seo-table-wrap {
  margin-top: 30px;
  overflow-x: auto;
  border: 2px solid var(--seo-ink);
  background: var(--seo-white);
}

.seo-table-wrap:focus-visible { outline: 4px solid var(--seo-coral); }

.seo-table-wrap table {
  width: 100%;
  min-width: 720px;
  border-collapse: collapse;
  font-size: 0.82rem;
  line-height: 1.65;
}

.seo-table-wrap th,
.seo-table-wrap td {
  padding: 17px;
  border-right: 1px solid var(--seo-line);
  border-bottom: 1px solid var(--seo-line);
  text-align: left;
  vertical-align: top;
}

.seo-table-wrap thead th {
  background: var(--seo-ink);
  color: var(--seo-white);
  font-weight: 900;
}

.seo-table-wrap tbody th {
  min-width: 130px;
  background: var(--seo-paper-deep);
  font-weight: 950;
}

.seo-primary-cta {
  margin: clamp(46px, 8vw, 82px) clamp(20px, 6vw, 64px) clamp(54px, 8vw, 86px);
  padding: clamp(30px, 6vw, 58px);
  border: 2px solid var(--seo-ink);
  background: var(--seo-paper);
  box-shadow: 8px 8px 0 var(--seo-coral);
}

.seo-primary-cta > p { color: var(--seo-blue); }
.seo-primary-cta h2 { margin-top: 16px; }

.seo-primary-cta > span {
  max-width: 650px;
  margin-top: 20px;
  display: block;
  color: var(--seo-muted);
  font-weight: 700;
}

.seo-primary-cta > a {
  width: fit-content;
  min-height: 56px;
  margin-top: 28px;
  padding: 0 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--seo-ink);
  background: var(--seo-coral);
  box-shadow: 4px 4px 0 var(--seo-ink);
  font-size: 0.95rem;
  font-weight: 950;
  text-decoration: none;
}

.seo-primary-cta small {
  margin-top: 14px;
  display: block;
  color: var(--seo-muted);
  font-size: 0.7rem;
  font-weight: 750;
}

.seo-related {
  padding: clamp(64px, 10vw, 110px) 0;
}

.seo-related > p { color: var(--seo-blue); }
.seo-related h2 { margin-top: 14px; }

.seo-related > div {
  margin-top: 34px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.seo-related-card {
  min-height: 150px;
  padding: 25px;
  display: grid;
  align-content: space-between;
  gap: 20px;
  border: 2px solid var(--seo-ink);
  background: var(--seo-white);
  box-shadow: 5px 5px 0 var(--seo-blue);
  text-decoration: none;
}

.seo-related-card strong {
  font-size: 1.05rem;
  font-weight: 950;
  line-height: 1.45;
}

.seo-related-card span {
  color: var(--seo-muted);
  font-size: 0.78rem;
  font-weight: 700;
}

.seo-related-card:hover,
.seo-related-card:focus-visible,
.seo-primary-cta > a:hover,
.seo-primary-cta > a:focus-visible,
.seo-header-cta:hover,
.seo-header-cta:focus-visible {
  outline: 3px solid var(--seo-lime);
  outline-offset: 3px;
}

.seo-site-footer {
  min-height: 160px;
  padding: 36px max(20px, calc((100vw - 1080px) / 2));
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 24px 40px;
  border-top: 2px solid var(--seo-ink);
  background: var(--seo-ink);
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.74rem;
}

.seo-site-footer > div { display: grid; gap: 5px; }
.seo-site-footer strong { color: var(--seo-white); font-size: 1rem; }
.seo-site-footer nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 18px; }
.seo-site-footer a { min-height: 44px; display: inline-flex; align-items: center; color: var(--seo-white); }
.seo-site-footer > span { grid-column: 1 / -1; }

@media (max-width: 760px) {
  .seo-site-header { width: calc(100% - 28px); min-height: 68px; }
  .seo-site-header nav > a:first-child { display: none; }
  main { width: min(100% - 28px, 980px); }
  .seo-article { box-shadow: 6px 6px 0 var(--seo-blue); }
  .seo-hero h1 { font-size: clamp(2rem, 10vw, 3.25rem); }
  .seo-related > div { grid-template-columns: 1fr; }
  .seo-site-footer { grid-template-columns: 1fr; }
  .seo-site-footer nav { justify-content: flex-start; }
}

@media (max-width: 440px) {
  .seo-brand > span:last-child { display: none; }
  .seo-site-header .seo-header-cta { padding-inline: 12px; }
  .seo-hero { padding-inline: 22px; }
  .seo-answer-box,
  .seo-article-section,
  .seo-comparison,
  .seo-primary-cta { margin-inline: 18px; }
  .seo-content-list.is-ordered li { padding: 68px 18px 20px; }
  .seo-content-list.is-ordered li::before { top: 17px; left: 17px; }
  .seo-primary-cta > a { width: 100%; padding-inline: 14px; text-align: center; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}