:root {
  --page-bg: #fbfdff;
  --surface: #ffffff;
  --surface-soft: #f6f9fd;
  --text: #1f2328;
  --muted: #69727d;
  --line: #dfe7ef;
  --line-strong: #c8d7e5;
  --green: #28c76f;
  --green-dark: #158449;
  --blue: #6ecbff;
  --pink: #f6c3e2;
  --purple: #7b3ff2;
  --shadow: 0 24px 80px rgba(43, 69, 98, 0.12);
  --display: "IBM Plex Sans", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background:
    linear-gradient(rgba(141, 170, 210, 0.14) 1px, transparent 1px),
    linear-gradient(90deg, rgba(141, 170, 210, 0.14) 1px, transparent 1px),
    var(--page-bg);
  background-size: 88px 88px;
  color: var(--text);
  font-family: var(--display);
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }

.seo-shell {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.seo-nav {
  position: sticky;
  top: 16px;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: min(1120px, calc(100% - 32px));
  margin: 16px auto 0;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.88);
  box-shadow: 0 18px 60px rgba(32, 54, 78, 0.10);
  backdrop-filter: blur(18px);
}

.seo-brand,
.seo-nav-links,
.seo-nav-cta {
  display: flex;
  align-items: center;
}

.seo-brand {
  gap: 10px;
  font-weight: 800;
  font-size: 18px;
}

.seo-brand img {
  width: 26px;
  height: 26px;
  border-radius: 8px;
  display: block;
}

.seo-nav-links {
  gap: 24px;
  color: #5c6470;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.seo-nav-links a:hover { color: var(--text); }

.seo-nav-cta {
  min-height: 40px;
  padding: 0 18px;
  border-radius: 999px;
  background: #111111;
  color: #ffffff;
  font-weight: 800;
  box-shadow: 0 16px 40px rgba(20, 20, 20, 0.12);
}

.seo-hero {
  padding: 96px 0 54px;
  text-align: center;
}

.seo-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 30px;
  padding: 0 14px;
  border: 1px solid rgba(40, 199, 111, 0.34);
  border-radius: 999px;
  background: rgba(40, 199, 111, 0.10);
  color: var(--green-dark);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.seo-hero h1,
.seo-section h2 {
  margin: 18px auto 0;
  max-width: 900px;
  color: #101418;
  font-size: clamp(42px, 7vw, 86px);
  line-height: 0.95;
  letter-spacing: -0.045em;
}

.seo-hero p {
  margin: 24px auto 0;
  max-width: 720px;
  color: var(--muted);
  font-size: clamp(18px, 2.3vw, 24px);
  line-height: 1.45;
}

.seo-hero-actions {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 32px;
}

.seo-button,
.seo-button-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 999px;
  font-weight: 800;
  border: 1px solid var(--line);
}

.seo-button {
  background: #111111;
  color: #ffffff;
  box-shadow: 0 18px 45px rgba(18, 18, 18, 0.16);
}

.seo-button:hover {
  background: linear-gradient(90deg, #ee6fb8, #67caff);
  color: #ffffff;
  border-color: transparent;
}

.seo-button-secondary {
  background: #ffffff;
  color: #303741;
}

.seo-gradient-panel {
  margin-top: 48px;
  padding: 48px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background:
    linear-gradient(90deg, rgba(246, 195, 226, 0.54), rgba(255, 255, 255, 0.74) 48%, rgba(110, 203, 255, 0.52)),
    linear-gradient(rgba(255, 255, 255, 0.38) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.38) 1px, transparent 1px);
  background-size: auto, 64px 64px, 64px 64px;
  box-shadow: var(--shadow);
}

.seo-card-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.seo-card,
.seo-form-card,
.seo-article-card,
.seo-compare-card {
  border: 1px solid var(--line);
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 20px 55px rgba(38, 64, 91, 0.10);
}

.seo-card,
.seo-article-card,
.seo-compare-card { padding: 24px; }

.seo-card h2,
.seo-card h3,
.seo-article-card h2,
.seo-article-card h3,
.seo-compare-card h2,
.seo-compare-card h3 {
  margin: 0;
  font-size: 24px;
  line-height: 1.05;
  letter-spacing: -0.03em;
}

.seo-card p,
.seo-article-card p,
.seo-compare-card p {
  color: var(--muted);
  font-size: 16px;
  line-height: 1.55;
}

.seo-card-meta {
  display: inline-flex;
  align-items: center;
  margin-bottom: 18px;
  color: var(--green-dark);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.seo-section { padding: 72px 0; }

.seo-section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 30px;
  margin-bottom: 28px;
}

.seo-section h2 {
  margin: 12px 0 0;
  max-width: 760px;
  font-size: clamp(36px, 5vw, 64px);
}

.seo-section-head p {
  max-width: 460px;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.5;
}

.seo-two-col {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
  gap: 24px;
  align-items: start;
}

.seo-form-card { padding: 26px; }

.seo-field {
  display: grid;
  gap: 8px;
  margin-bottom: 14px;
}

.seo-field label {
  color: #3d4650;
  font-size: 14px;
  font-weight: 800;
}

.seo-field input,
.seo-field textarea,
.seo-field select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #ffffff;
  color: var(--text);
  font: inherit;
  padding: 13px 14px;
  outline: none;
}

.seo-field textarea { min-height: 104px; resize: vertical; }

.seo-field input:focus,
.seo-field textarea:focus,
.seo-field select:focus {
  border-color: #78cdf5;
  box-shadow: 0 0 0 4px rgba(110, 203, 255, 0.18);
}

.seo-output {
  min-height: 420px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background:
    linear-gradient(rgba(255, 255, 255, 0.72), rgba(255, 255, 255, 0.92)),
    linear-gradient(90deg, rgba(246, 195, 226, 0.34), rgba(110, 203, 255, 0.28));
  box-shadow: var(--shadow);
}

.seo-output h2,
.seo-output h3 {
  margin: 0 0 12px;
  font-size: 26px;
  line-height: 1.08;
}

.seo-output-list {
  display: grid;
  gap: 12px;
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.seo-output-list li {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.82);
}

.seo-output-list strong { display: block; margin-bottom: 6px; }
.seo-output-list span { color: var(--muted); line-height: 1.45; }

.seo-table {
  width: 100%;
  border-collapse: collapse;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: #ffffff;
  box-shadow: var(--shadow);
}

.seo-table th,
.seo-table td {
  padding: 18px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.seo-table th {
  color: #4a535f;
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.seo-table td:first-child {
  color: #111111;
  font-weight: 800;
}

.seo-check-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  padding: 0;
  list-style: none;
}

.seo-check-list li {
  display: flex;
  gap: 12px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: #ffffff;
}

.seo-check-list li::before {
  content: "v";
  display: grid;
  place-items: center;
  flex: 0 0 24px;
  height: 24px;
  border: 2px solid var(--green);
  border-radius: 50%;
  color: var(--green-dark);
  font-weight: 900;
  font-size: 13px;
}

.seo-resource-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.seo-article {
  max-width: 780px;
  margin: 0 auto;
  padding: 84px 0;
}

.seo-article h1 {
  margin: 18px 0 24px;
  font-size: clamp(42px, 6vw, 76px);
  line-height: 0.95;
  letter-spacing: -0.045em;
}

.seo-article h2 {
  margin-top: 44px;
  font-size: 30px;
  letter-spacing: -0.03em;
}

.seo-article p,
.seo-article li {
  color: #4e5965;
  font-size: 19px;
  line-height: 1.68;
}

.seo-article ul { padding-left: 22px; }

.seo-footer {
  margin-top: 56px;
  padding: 52px 0 36px;
  border-top: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.74);
}

.seo-footer-grid {
  display: grid;
  grid-template-columns: 1.3fr repeat(4, minmax(0, 1fr));
  gap: 24px;
}

.seo-footer h4 {
  margin: 0 0 12px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: #596371;
  text-transform: uppercase;
}

.seo-footer a {
  display: block;
  margin-top: 9px;
  color: #68727e;
  font-size: 14px;
  font-weight: 700;
}

.seo-footer a:hover { color: var(--text); }

.seo-footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  margin-top: 42px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  color: #77818d;
  font-size: 13px;
}

@media (max-width: 860px) {
  .seo-nav { align-items: flex-start; border-radius: 24px; }
  .seo-nav-links { display: none; }
  .seo-hero { padding-top: 64px; }
  .seo-card-grid,
  .seo-two-col,
  .seo-check-list,
  .seo-resource-grid,
  .seo-footer-grid {
    grid-template-columns: 1fr;
  }
  .seo-gradient-panel { padding: 24px; }
  .seo-section-head { display: block; }
}