:root {
  --ink: #151515;
  --ink-muted: #666;
  --ink-subtle: #888;
  --surface: #ffffff;
  --surface-muted: #f8f8f6;
  --canvas: #f3f3f0;
  --line: #e3e3de;
  --line-strong: #cfcfc8;
  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 18px;
  --radius-xl: 22px;
  --shadow-soft: 0 1px 2px rgba(21, 21, 21, 0.04);
  --shadow-card: 0 10px 40px rgba(21, 21, 21, 0.06);
  --transition: 160ms ease;

  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--canvas);
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at 50% -20%, #ffffff 0, var(--canvas) 52%);
}

a {
  color: inherit;
}

.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.topbar {
  width: min(1100px, calc(100% - 40px));
  margin: 0 auto;
  padding: 22px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: -0.02em;
  font-size: 15px;
  text-decoration: none;
}

.brand:hover {
  opacity: 0.82;
}

.brand-mark {
  width: 28px;
  height: 28px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(2, 1fr);
  gap: 2px;
  padding: 6px;
  border-radius: 8px;
  background: var(--ink);
}

.brand-mark span {
  display: block;
  border-radius: 1px;
  background: #fff;
  opacity: 0.92;
}

.topbar-note {
  color: var(--ink-subtle);
  font-size: 13px;
}

.guide-main {
  flex: 1;
  width: min(760px, calc(100% - 40px));
  margin: 0 auto;
  padding: 12px 0 80px;
}

.guide-hero {
  margin-bottom: 36px;
}

.eyebrow {
  color: var(--ink-subtle);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1 {
  margin: 14px 0 0;
  font-size: clamp(34px, 6.4vw, 52px);
  line-height: 1.08;
  letter-spacing: -0.045em;
  font-weight: 800;
}

.guide-lede,
.guide-article p,
.guide-article li {
  color: var(--ink-muted);
  font-size: 17px;
  line-height: 1.65;
}

.guide-lede {
  margin: 18px 0 0;
}

.guide-article h2 {
  margin: 36px 0 0;
  font-size: 22px;
  letter-spacing: -0.03em;
  font-weight: 700;
  color: var(--ink);
}

.guide-article h3 {
  margin: 0;
  font-size: 16px;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.guide-article ul {
  margin: 14px 0 0;
  padding-left: 20px;
}

.guide-article li + li {
  margin-top: 8px;
}

.guide-cta-row {
  margin: 28px 0 0;
}

.guide-cta-note {
  margin: 12px 0 0;
  color: var(--ink-subtle);
  font-size: 13px;
}

.primary-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: var(--radius-sm);
  padding: 12px 18px;
  font-weight: 700;
  font-size: 14px;
  text-decoration: none;
  background: var(--ink);
  color: #fff;
  transition:
    background var(--transition),
    transform var(--transition);
}

.primary-button.large {
  padding: 14px 22px;
  font-size: 15px;
}

.primary-button:hover {
  background: #2a2a2a;
  transform: translateY(-1px);
}

.primary-button:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 2px;
}

.guide-cta-card {
  margin-top: 40px;
  padding: 24px 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow-card);
}

.guide-cta-card h2 {
  margin: 0;
  font-size: 20px;
}

.guide-cta-card p {
  margin: 10px 0 18px;
}

.guide-faq {
  margin-top: 12px;
}

.guide-faq-item {
  margin-top: 16px;
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.72);
}

.guide-faq-item p {
  margin: 8px 0 0;
  font-size: 15px;
}

.guide-related {
  margin-top: 40px;
}

.guide-related ul {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 10px;
}

.guide-related a {
  display: block;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
  text-decoration: none;
  transition: border-color var(--transition), transform var(--transition);
}

.guide-related a:hover {
  border-color: var(--line-strong);
  transform: translateY(-1px);
}

.guide-related strong,
.guide-related span {
  display: block;
}

.guide-related strong {
  font-size: 14px;
  letter-spacing: -0.02em;
}

.guide-related span {
  margin-top: 4px;
  color: var(--ink-subtle);
  font-size: 13px;
  line-height: 1.45;
  font-weight: 400;
}

footer {
  width: min(960px, calc(100% - 40px));
  margin: auto;
  padding: 24px 0 32px;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 20px;
  color: var(--ink-subtle);
  font-size: 12px;
  line-height: 1.5;
}

@media (max-width: 768px) {
  .topbar-note {
    display: none;
  }

  h1 {
    font-size: 34px;
  }

  .guide-lede,
  .guide-article p,
  .guide-article li {
    font-size: 16px;
  }

  footer {
    flex-direction: column;
  }
}

@media (max-width: 430px) {
  .topbar,
  .guide-main,
  footer {
    width: min(100% - 28px, 960px);
  }

  .primary-button.large {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}