:root {
  --ink: #12141a;
  --paper: #f3efe6;
  --paper-2: #e8e2d4;
  --mute: #5c5a54;
  --accent: #c23b22;
  --line: rgba(18, 20, 26, 0.12);
  --font-display: "Fraunces", "Songti SC", "Noto Serif SC", serif;
  --font-body: "IBM Plex Sans", "PingFang SC", "Hiragino Sans GB", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(194, 59, 34, 0.08), transparent 55%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper-2) 100%);
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: 1.65;
  min-height: 100vh;
}

.skip {
  position: absolute;
  left: -999px;
  top: 0;
}
.skip:focus {
  left: 1rem;
  top: 1rem;
  z-index: 10;
  background: var(--ink);
  color: var(--paper);
  padding: 0.5rem 0.75rem;
}

.top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem clamp(1.25rem, 4vw, 3rem);
  border-bottom: 1px solid var(--line);
}

.brand {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 650;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
}

.top nav {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.top a {
  color: var(--mute);
  text-decoration: none;
  font-size: 0.92rem;
}
.top a:hover {
  color: var(--accent);
}

.nav-gh {
  color: var(--ink) !important;
  font-weight: 500;
}

.hero {
  padding: clamp(3.5rem, 12vh, 7rem) clamp(1.25rem, 4vw, 3rem) clamp(3rem, 8vh, 5rem);
  max-width: 52rem;
}

.kicker {
  margin: 0 0 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 650;
  font-size: clamp(2.4rem, 7vw, 4.2rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  max-width: 12ch;
  animation: rise 0.7s ease both;
}

.lede {
  margin: 1.5rem 0 0;
  color: var(--mute);
  font-size: clamp(1.05rem, 2.4vw, 1.25rem);
  max-width: 36rem;
  animation: rise 0.7s ease 0.08s both;
}

.cta-row {
  margin: 2rem 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  animation: rise 0.7s ease 0.16s both;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  padding: 0.65rem 1.2rem;
  border-radius: 2px;
  text-decoration: none;
  font-weight: 500;
  transition: transform 0.15s ease, background 0.15s ease, color 0.15s ease;
}
.btn:active {
  transform: translateY(1px);
}
.btn.primary {
  background: var(--ink);
  color: var(--paper);
}
.btn.primary:hover {
  background: var(--accent);
}
.btn.ghost {
  border: 1px solid var(--ink);
  color: var(--ink);
}
.btn.ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.strip {
  margin: 0 clamp(1.25rem, 4vw, 3rem);
  padding: 1.25rem 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  max-width: 40rem;
  color: var(--mute);
}
.strip strong {
  color: var(--ink);
  font-weight: 500;
}

.block {
  padding: clamp(3rem, 8vh, 5rem) clamp(1.25rem, 4vw, 3rem);
  max-width: 48rem;
}

.block h2 {
  margin: 0 0 1.75rem;
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3.5vw, 2.1rem);
  letter-spacing: -0.02em;
}

.rail {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1.75rem;
}

.rail li {
  display: grid;
  grid-template-columns: 3.5rem 1fr;
  gap: 1rem;
  align-items: start;
}

.rail .n {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  padding-top: 0.35rem;
}

.rail h3 {
  margin: 0 0 0.35rem;
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 650;
}

.rail p {
  margin: 0;
  color: var(--mute);
}

.hint {
  margin: 0 0 1rem;
  color: var(--mute);
}

.code {
  margin: 0 0 1.5rem;
  padding: 1rem 1.15rem;
  background: var(--ink);
  color: var(--paper);
  overflow-x: auto;
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

.steps {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--mute);
}
.steps li {
  margin: 0.4rem 0;
}
.steps code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  color: var(--ink);
}

.more {
  margin: 1.5rem 0 0;
  color: var(--mute);
}
.more a {
  color: var(--accent);
}

.seek-list {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--mute);
}
.seek-list li {
  margin: 0.55rem 0;
}

.ban {
  margin: 0;
  padding: 0;
  list-style: none;
  border-left: 3px solid var(--accent);
  padding-left: 1.25rem;
}
.ban li {
  margin: 0.55rem 0;
  color: var(--mute);
}

.foot {
  padding: 2.5rem clamp(1.25rem, 4vw, 3rem) 3rem;
  border-top: 1px solid var(--line);
  color: var(--mute);
  font-size: 0.92rem;
}
.foot a {
  color: var(--ink);
}
.credit {
  margin: 0.5rem 0 0;
  font-size: 0.82rem;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(0.6rem);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .hero h1,
  .lede,
  .cta-row {
    animation: none;
  }
}

@media (max-width: 560px) {
  .rail li {
    grid-template-columns: 2.5rem 1fr;
  }
}