:root {
  --p: #007aff;
  --p-rgb: 0,122,255;
  --bg: #faf9f7;
  --ink: #1c1917;
  --ink-secondary: #57534e;
  --ink-tertiary: #a8a29e;
  --surface: #fff;
  --rule: #e7e5e4;
  --serif: Georgia, "Times New Roman", serif;
  --sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --content-w: 820px;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
}

nav {
  align-items: center;
  background: rgba(250, 249, 247, 0.9);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--rule);
  display: flex;
  justify-content: space-between;
  padding: 0.9rem clamp(1rem, 4vw, 2rem);
  position: sticky;
  top: 0;
  z-index: 100;
}

nav .home {
  font-weight: 750;
  letter-spacing: -0.01em;
  text-decoration: none;
}

nav .dl,
.btn {
  background: var(--ink);
  border-radius: 999px;
  color: var(--bg);
  display: inline-flex;
  font-size: 0.9rem;
  font-weight: 700;
  justify-content: center;
  line-height: 1.2;
  padding: 0.68rem 1.25rem;
  text-decoration: none;
  transition: background 0.25s var(--ease-out), box-shadow 0.25s var(--ease-out), transform 0.25s var(--ease-out);
}

nav .dl:hover,
.btn:hover {
  background: var(--p);
  box-shadow: 0 8px 24px rgba(var(--p-rgb), 0.22);
  transform: translateY(-1px);
}

.hero {
  margin: 0 auto;
  max-width: 980px;
  padding: clamp(4rem, 9vw, 7.5rem) clamp(1rem, 5vw, 2rem) clamp(3rem, 7vw, 5rem);
  text-align: center;
}

.badge {
  background: rgba(var(--p-rgb), 0.1);
  border: 1px solid rgba(var(--p-rgb), 0.22);
  border-radius: 999px;
  color: var(--p);
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  margin-bottom: 1.35rem;
  padding: 0.35rem 0.78rem;
  text-transform: uppercase;
}

h1,
h2,
.ed-section-num {
  font-family: var(--serif);
}

h1 {
  font-size: clamp(2.5rem, 7vw, 5.6rem);
  font-weight: 700;
  letter-spacing: 0;
  line-height: 0.96;
  margin: 0 auto 1.4rem;
  max-width: 960px;
}

.hero p {
  color: var(--ink-secondary);
  font-size: clamp(1.12rem, 2.5vw, 1.45rem);
  line-height: 1.55;
  margin: 0 auto;
  max-width: 760px;
}

.ed-main {
  border-top: 1px solid var(--rule);
}

main {
  margin: 0 auto;
  max-width: 1120px;
  padding: 0 clamp(1rem, 4vw, 2rem) 5rem;
}

.ed-section {
  border-bottom: 1px solid var(--rule);
}

.ed-section-inner {
  display: grid;
  gap: clamp(1.5rem, 5vw, 4rem);
  grid-template-columns: minmax(4rem, 10rem) minmax(0, var(--content-w));
  padding: clamp(2.6rem, 7vw, 5rem) 0;
}

.ed-section-num {
  color: var(--ink-tertiary);
  font-size: clamp(2rem, 6vw, 4.75rem);
  line-height: 0.9;
}

.ed-section-body h2 {
  font-size: clamp(1.7rem, 4vw, 3rem);
  font-weight: 650;
  line-height: 1.08;
  margin-bottom: 1rem;
}

.ed-lead,
.ed-section-body p {
  color: var(--ink-secondary);
  font-size: 1.06rem;
  margin-bottom: 1rem;
}

.answer-strip {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 8px;
  margin: 0 auto 3rem;
  max-width: 900px;
  padding: clamp(1.25rem, 4vw, 2rem);
}

.answer-strip strong {
  display: block;
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  margin-bottom: 0.5rem;
  text-transform: uppercase;
}

.faq-grid,
.related-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 1.5rem;
}

.faq-item,
.related-card {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 1.2rem;
}

.faq-item h3,
.related-card h3 {
  font-size: 1rem;
  line-height: 1.3;
  margin-bottom: 0.55rem;
}

.faq-item p,
.related-card p {
  color: var(--ink-secondary);
  font-size: 0.98rem;
  line-height: 1.55;
}

.related-card {
  text-decoration: none;
  transition: border-color 0.2s var(--ease-out), transform 0.2s var(--ease-out);
}

.related-card:hover {
  border-color: rgba(var(--p-rgb), 0.45);
  transform: translateY(-1px);
}

.cta {
  background: var(--ink);
  border-radius: 8px;
  color: var(--bg);
  margin: clamp(2.5rem, 7vw, 5rem) auto 0;
  max-width: 900px;
  padding: clamp(2rem, 6vw, 4rem);
  text-align: center;
}

.cta h2 {
  font-size: clamp(2rem, 5vw, 4rem);
  line-height: 1;
  margin-bottom: 1rem;
}

.cta p {
  color: rgba(250, 249, 247, 0.78);
  font-size: 1.1rem;
  margin: 0 auto 1.5rem;
  max-width: 640px;
}

.cta .btn {
  background: var(--bg);
  color: var(--ink);
}

footer {
  border-top: 1px solid var(--rule);
  color: var(--ink-secondary);
  padding: 2rem;
  text-align: center;
}

footer a {
  text-decoration: none;
}

@media (max-width: 760px) {
  nav {
    gap: 1rem;
  }

  nav .dl {
    padding: 0.58rem 0.95rem;
  }

  .ed-section-inner {
    grid-template-columns: 1fr;
  }

  .ed-section-num {
    font-size: 2.5rem;
  }

  .faq-grid,
  .related-grid {
    grid-template-columns: 1fr;
  }
}