:root {
  color-scheme: dark;
  --bg: #080808;
  --surface: #111;
  --surface-2: #181818;
  --text: #f5f5f2;
  --muted: #b1b1aa;
  --line: #2b2b28;
  --accent: #ffd84a;
  --accent-ink: #171200;
  --max: 900px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  background:
    radial-gradient(circle at 78% 0%, rgba(255, 216, 74, 0.12), transparent 30rem),
    var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.65;
}

a {
  color: inherit;
}

a:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 4px;
  border-radius: 4px;
}

header {
  min-height: 72px;
  padding: 0 max(20px, calc((100vw - 1120px) / 2));
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid var(--line);
  background: rgba(8, 8, 8, 0.88);
  backdrop-filter: blur(18px);
}

header .brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 800;
  letter-spacing: -0.02em;
}

header .brand img {
  width: 36px;
  height: 36px;
  border-radius: 10px;
}

header nav {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 0.95rem;
  font-weight: 650;
}

header nav a {
  margin: 0;
  color: var(--muted);
  text-decoration: none;
}

header nav a:hover {
  color: var(--text);
  text-decoration: none;
}

main {
  width: min(var(--max), calc(100% - 40px));
  max-width: none;
  margin: 0 auto;
  padding: 86px 0 100px;
}

main#guide::before {
  content: "Height AI guide";
  display: block;
  margin-bottom: 18px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

h1 {
  max-width: 880px;
  margin: 0;
  color: var(--text);
  font-size: clamp(3rem, 7vw, 5.6rem);
  line-height: 0.98;
  letter-spacing: -0.06em;
  overflow-wrap: break-word;
  text-wrap: balance;
}

main > h1 + p {
  max-width: 760px;
  margin: 28px 0 68px;
  color: var(--muted);
  font-size: clamp(1.08rem, 2vw, 1.28rem);
}

h2 {
  margin: 64px 0 18px;
  color: var(--text);
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.08;
  letter-spacing: -0.04em;
  text-wrap: balance;
}

p,
li {
  color: var(--muted);
  font-size: 1.06rem;
}

p {
  margin: 1rem 0;
}

strong {
  color: var(--text);
}

main a {
  color: var(--accent);
  text-underline-offset: 3px;
}

main > ul,
main > ol {
  margin: 26px 0;
  padding: 22px 28px 22px 52px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(17, 17, 17, 0.78);
}

li + li {
  margin-top: 0.75rem;
}

li::marker {
  color: var(--accent);
  font-weight: 800;
}

.cta {
  margin-top: 72px;
  padding: clamp(28px, 5vw, 48px);
  border: 1px solid #3a3520;
  border-radius: 24px;
  background: linear-gradient(145deg, #211d0d, #12110c);
  text-align: left;
}

.cta h2 {
  margin: 0 0 14px;
  font-size: clamp(1.9rem, 4vw, 2.7rem);
}

.cta p {
  max-width: 650px;
}

.cta a {
  display: inline-flex;
  margin-top: 10px;
  padding: 13px 20px;
  border-radius: 999px;
  background: var(--accent);
  color: var(--accent-ink);
  font-weight: 800;
  text-decoration: none;
  transition: background 0.2s ease;
}

.cta a:hover {
  background: #ffe577;
}

.faq {
  margin-top: 72px;
}

.faq h2 {
  margin-top: 0;
}

.faq details {
  margin: 0;
  padding: 0;
  border: 0;
  border-top: 1px solid var(--line);
  border-radius: 0;
  background: transparent;
  box-shadow: none;
}

.faq details:last-child {
  border-bottom: 1px solid var(--line);
}

.faq summary {
  position: relative;
  padding: 21px 42px 21px 0;
  color: var(--text);
  font-size: 1.08rem;
  font-weight: 750;
  cursor: pointer;
  list-style: none;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::after {
  content: "+";
  position: absolute;
  right: 4px;
  color: var(--accent);
  font-size: 1.5rem;
  font-weight: 400;
}

.faq details[open] summary::after {
  content: "−";
}

.faq details p {
  margin: 0 0 22px;
}

.related {
  margin-top: 72px;
  padding-top: 0;
  border-top: 0;
}

.related h2 {
  margin-top: 0;
}

.related ul {
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  list-style: none;
}

.related li {
  margin: 0;
}

.related a,
a.guide-link {
  display: block;
  height: 100%;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  color: var(--text);
  font-weight: 700;
  text-decoration: none;
}

.related a:hover,
a.guide-link:hover {
  border-color: #575342;
  color: var(--accent);
  text-decoration: none;
}

main:not(#guide) > h2 + ul {
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  border: 0;
  background: transparent;
  list-style: none;
}

main:not(#guide) > h2 + ul li {
  margin: 0;
}

footer {
  padding: 34px max(20px, calc((100vw - 1120px) / 2)) 48px;
  border-top: 1px solid var(--line);
  background: #050505;
  color: #858580;
  text-align: center;
  font-size: 0.9rem;
}

footer p {
  margin: 0;
  color: #858580;
  font-size: 0.9rem;
}

footer a {
  color: var(--muted);
  font-weight: 650;
  text-decoration: none;
}

footer a:hover {
  color: var(--text);
  text-decoration: none;
}

@media (max-width: 680px) {
  header {
    min-height: 64px;
  }

  header .brand {
    font-size: 0.92rem;
  }

  header nav a:not(:first-child) {
    display: none;
  }

  main {
    width: calc(100% - 28px);
    padding: 58px 0 72px;
  }

  h1 {
    font-size: clamp(3rem, 15vw, 4.5rem);
  }

  main > h1 + p {
    margin-bottom: 50px;
  }

  main > ul,
  main > ol {
    padding: 20px 20px 20px 42px;
  }

  .related ul,
  main:not(#guide) > h2 + ul {
    grid-template-columns: 1fr;
  }
}