:root {
  color-scheme: light;
  --moon: #f3f6ff;
  --panel: #ffffff;
  --soft: #e8f2ff;
  --ink: #102033;
  --muted: #5c708a;
  --harbor: #3770bf;
  --harbor-dark: #244d85;
  --herb: #cef26d;
  --line: #d6e4f7;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--moon);
  color: var(--ink);
  font-family: A2Z, Pretendard, "Segoe UI", "Malgun Gothic", system-ui, sans-serif;
  word-break: keep-all;
  overflow-wrap: break-word;
}

a { color: inherit; }

.seo-header {
  background: var(--harbor);
  color: white;
  box-shadow: 0 16px 34px rgba(55, 112, 191, .18);
}

.seo-header__inner,
.seo-main,
.seo-footer {
  width: min(100% - 32px, 960px);
  margin-inline: auto;
}

.seo-header__inner { padding: 24px 0; }
.seo-brand {
  display: inline-flex;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 900;
  text-decoration: none;
  transition: opacity 120ms ease-out;
}
.seo-brand:hover { opacity: .82; }
.seo-brand:focus-visible { outline: 3px solid var(--herb); outline-offset: 4px; }
.seo-main { padding: 48px 0 64px; }
.seo-kicker { color: var(--harbor-dark); font-size: 13px; font-weight: 900; }

h1 {
  max-width: 820px;
  margin: 12px 0 18px;
  font-size: clamp(32px, 6vw, 48px);
  line-height: 1.12;
}

h2 { margin: 36px 0 12px; font-size: 23px; line-height: 1.25; }
p, li { font-size: 16px; font-weight: 650; line-height: 1.7; }
.seo-lead { max-width: 780px; color: var(--muted); font-size: 18px; }
.seo-nowrap { white-space: nowrap; }

.seo-card {
  margin-top: 28px;
  padding: 24px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 14px 34px rgba(31, 67, 112, .08);
}

.seo-card ul { margin: 0; padding-left: 22px; }
.seo-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }

.seo-button {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 10px 16px;
  border-radius: 8px;
  background: var(--herb);
  color: var(--ink);
  font-weight: 900;
  text-decoration: none;
  transition: transform 120ms ease-out;
}

.seo-button:hover { transform: translateY(-1px); }
.seo-button:focus-visible { outline: 3px solid var(--ink); outline-offset: 3px; }
.seo-footer { padding: 24px 0 40px; color: var(--muted); border-top: 1px solid var(--line); }

@media (prefers-reduced-motion: reduce) {
  .seo-brand,
  .seo-button { transition: none; }
  .seo-button:hover { transform: none; }
}

@media (max-width: 480px) {
  .seo-main { padding-top: 40px; }
  h1 { font-size: 28px; line-height: 1.18; }
  .seo-mobile-line { display: block; }
}