:root {
  --bg: #f8fbf8;
  --panel: #ffffff;
  --ink: #15221b;
  --muted: #47594d;
  --line: #dce8df;
  --primary: #0f8a58;
  --primary-ink: #0b5b3a;
  --accent: #d2872a;
  --topbar-bg: rgba(248, 251, 248, 0.82);
  --topbar-line: rgba(21, 34, 27, 0.08);
  --kicker-bg: #f0f7f3;
  --block-bg: rgba(255, 255, 255, 0.92);
  --pre-bg: #f3f8f4;
  --pre-line: #d8e5db;
  --grid-line: rgba(21, 34, 27, 0.03);
  --ghost-bg: rgba(255, 255, 255, 0.65);
  --glow-primary: rgba(15, 138, 88, 0.1);
  --glow-accent: rgba(210, 135, 42, 0.15);
  --mono: "IBM Plex Mono", monospace;
  --sans: "Space Grotesk", sans-serif;
}

html[data-theme="dark"] {
  --bg: #0d1218;
  --panel: #131b24;
  --ink: #e8f0f6;
  --muted: #9fb2c2;
  --line: #253544;
  --primary: #2f86ff;
  --primary-ink: #89bcff;
  --accent: #35d4e5;
  --topbar-bg: rgba(13, 18, 24, 0.82);
  --topbar-line: rgba(232, 240, 246, 0.12);
  --kicker-bg: #162332;
  --block-bg: rgba(19, 27, 36, 0.92);
  --pre-bg: #101821;
  --pre-line: #223343;
  --grid-line: rgba(232, 240, 246, 0.06);
  --ghost-bg: rgba(20, 30, 40, 0.7);
  --glow-primary: rgba(47, 134, 255, 0.22);
  --glow-accent: rgba(53, 212, 229, 0.2);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--sans);
}

.bg-grid {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(circle at 0% 0%, var(--glow-primary), transparent 35%),
    radial-gradient(circle at 100% 20%, var(--glow-accent), transparent 30%),
    linear-gradient(transparent 95%, var(--grid-line) 95%),
    linear-gradient(90deg, transparent 95%, var(--grid-line) 95%);
  background-size: auto, auto, 28px 28px, 28px 28px;
}

.wrap {
  width: min(1100px, calc(100% - 2.4rem));
  margin: 0 auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(9px);
  background: var(--topbar-bg);
  border-bottom: 1px solid var(--topbar-line);
}

.topbar-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 68px;
}

.brand {
  font-weight: 700;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: 0.02em;
}

.topbar nav {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.topbar nav a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.93rem;
  font-weight: 500;
}

.hero {
  padding: 5.6rem 0 3rem;
}

.kicker {
  display: inline-block;
  margin: 0;
  padding: 0.25rem 0.65rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 0.74rem;
  color: var(--primary-ink);
  background: var(--kicker-bg);
}

h1 {
  margin: 0.95rem 0 0.6rem;
  font-size: clamp(2.1rem, 5vw, 3.8rem);
  line-height: 1.05;
}

.lead {
  max-width: 740px;
  color: var(--muted);
  line-height: 1.65;
  font-size: 1.06rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.3rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  border-radius: 0.72rem;
  padding: 0.7rem 1rem;
  font-size: 0.93rem;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn.primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 10px 22px rgba(15, 138, 88, 0.22);
}

.btn.ghost {
  border-color: var(--line);
  color: var(--ink);
  background: var(--ghost-bg);
}

.block {
  margin-top: 2.2rem;
  padding: 1.3rem;
  border-radius: 1rem;
  border: 1px solid var(--line);
  background: var(--block-bg);
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.8rem;
}

h2 {
  margin: 0;
  font-size: clamp(1.35rem, 2vw, 2rem);
}

.copy-btn {
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
  border-radius: 0.65rem;
  padding: 0.45rem 0.75rem;
  font-family: var(--mono);
  font-size: 0.75rem;
  cursor: pointer;
}

.copy-btn.done {
  border-color: var(--primary);
  color: var(--primary-ink);
}

pre {
  margin: 0;
  overflow: auto;
  border-radius: 0.85rem;
  border: 1px solid var(--pre-line);
  background: var(--pre-bg);
  padding: 1rem;
}

code {
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.55;
}

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

.card {
  border: 1px solid var(--line);
  border-radius: 0.95rem;
  padding: 1rem;
  background: var(--panel);
}

.theme-toggle {
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
  border-radius: 999px;
  padding: 0.3rem 0.62rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  cursor: pointer;
}

.card h3 {
  margin: 0 0 0.5rem;
}

.card p,
.card li {
  color: var(--muted);
  line-height: 1.6;
}

.card ul,
.card ol {
  margin: 0;
  padding-left: 1.2rem;
}

.limits-list {
  margin-top: 1rem;
  padding-left: 1.2rem;
}

.limits-list li {
  margin: 0.34rem 0;
  line-height: 1.55;
  color: var(--muted);
}

.positioning {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px dashed var(--line);
  color: var(--ink);
  font-weight: 500;
}

.footer {
  padding: 2.5rem 0 2rem;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.78rem;
}

.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.45s ease, transform 0.45s ease;
}

.reveal.in {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 860px) {
  .topbar-inner {
    min-height: 62px;
  }

  .topbar nav {
    gap: 0.6rem;
    flex-wrap: wrap;
    justify-content: flex-end;
  }

  .topbar nav a {
    font-size: 0.8rem;
  }

  .grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 4.6rem;
  }

  .section-head {
    flex-direction: column;
    align-items: flex-start;
  }
}