:root {
  --ink: #1a1a21;
  --text: #3c3b44;
  --muted: #6e6c78;
  --line: #e4e1ec;
  --paper: #f7f5fc;
  --card: #ffffff;
  --brand: #3d42e0;
  --brand-deep: #2a2e9e;
  --soft: #e0e0ff;
  --violet: #6b3ff2;
  --chip: #f1eef8;
  --shadow: 0 18px 40px rgba(26, 26, 33, 0.06);
  --header: rgba(247, 245, 252, 0.92);
  --radius: 22px;
  --max: 1120px;
  --sans: "Segoe UI", system-ui, -apple-system, Roboto, "Helvetica Neue", sans-serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e5e2ea;
    --text: #d5d2db;
    --muted: #b0acb8;
    --line: #34343b;
    --paper: #121218;
    --card: #1c1c24;
    --brand: #c2c4ff;
    --brand-deep: #e0e0ff;
    --soft: #2a2c55;
    --violet: #d4c4ff;
    --chip: #292930;
    --shadow: 0 18px 40px rgba(0, 0, 0, 0.28);
    --header: rgba(18, 18, 24, 0.92);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  color: var(--text);
  background: var(--paper);
  line-height: 1.6;
  font-size: 1.0625rem;
}

img, svg, audio { max-width: 100%; }

img { height: auto; }

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

a:hover { color: var(--brand-deep); }

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 3px;
}

.skip {
  position: absolute;
  left: 1rem;
  top: -4rem;
  background: var(--card);
  color: var(--ink);
  padding: 0.6rem 0.9rem;
  border-radius: 10px;
  z-index: 5;
}

.skip:focus { top: 0.75rem; }

.wrap {
  width: min(var(--max), calc(100% - 2rem));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 4;
  background: var(--header);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  width: min(var(--max), calc(100% - 2rem));
  margin: 0 auto;
  min-height: 72px;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
  letter-spacing: -0.03em;
  font-size: 1.05rem;
}

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

.nav-toggle {
  margin-left: auto;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--ink);
  border-radius: 999px;
  min-height: 44px;
  padding: 0 0.95rem;
  font: inherit;
  font-size: 0.95rem;
}

.nav {
  display: none;
  position: absolute;
  left: 0;
  right: 0;
  top: 72px;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
  padding: 0.5rem 1rem 1rem;
}

.nav.is-open { display: grid; }

.nav a {
  color: var(--ink);
  text-decoration: none;
  padding: 0.75rem 0.2rem;
  font-size: 1rem;
}

.nav a:hover { color: var(--brand); }

.nav a.btn,
.nav a.btn:hover {
  color: #fff;
}

@media (prefers-color-scheme: dark) {
  .nav a.btn,
  .nav a.btn:hover { color: #16178a; }
}

.nav .btn { margin-top: 0.4rem; }

h1, h2, h3 {
  color: var(--ink);
  line-height: 1.15;
  letter-spacing: -0.03em;
  font-weight: 600;
}

h1 {
  font-size: clamp(2.4rem, 7vw, 4.6rem);
  margin: 0 0 1rem;
  font-weight: 700;
}

h2 {
  font-size: clamp(1.7rem, 3vw, 2.3rem);
  margin: 0 0 0.75rem;
}

h3 { font-size: 1.15rem; margin: 0 0 0.4rem; }

.eyebrow {
  margin: 0 0 0.8rem;
  color: var(--brand);
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.lede {
  font-size: 1.15rem;
  max-width: 40rem;
  margin: 0 0 1.4rem;
}

.hero {
  padding: 2.5rem 0 3.5rem;
}

.hero-grid {
  display: grid;
  gap: 2rem;
  align-items: center;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  margin-bottom: 1.4rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  min-height: 48px;
  padding: 0.7rem 1.15rem;
  border-radius: 999px;
  background: var(--brand);
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: -0.01em;
  border: 0;
}

@media (prefers-color-scheme: dark) {
  .btn { color: #16178a; }
}

.btn:hover { color: #fff; filter: brightness(1.08); }

@media (prefers-color-scheme: dark) {
  .btn:hover { color: #16178a; }
}

.btn svg { width: 16px; height: 16px; fill: currentColor; }

.btn-ghost {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}

.btn-ghost:hover { color: var(--ink); filter: none; background: var(--card); }

.trust {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 640px) {
  .trust { grid-template-columns: 1fr 1fr; }
}

.trust li {
  margin: 0;
  padding-left: 0.9rem;
  border-left: 2px solid var(--brand);
  color: var(--ink);
  font-size: 0.95rem;
}

.trust span {
  display: block;
  color: var(--muted);
  font-size: 0.82rem;
}

.panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 28px;
  box-shadow: var(--shadow);
  padding: 1.3rem;
}

.panel-top {
  display: flex;
  gap: 0.9rem;
  align-items: center;
  margin-bottom: 1rem;
}

.panel-top img {
  width: 72px;
  height: 72px;
  border-radius: 18px;
}

.panel-top strong {
  display: block;
  color: var(--ink);
  font-size: 1.15rem;
  letter-spacing: -0.03em;
}

.panel-top span { color: var(--muted); font-size: 0.92rem; }

.sample {
  margin: 0 0 1rem;
  padding: 1rem 1rem 0.9rem;
  background: var(--paper);
  border-radius: 18px;
  color: var(--ink);
}

.sample p { margin: 0.35rem 0 0; }

.kicker {
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 700;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 0 0 1rem;
  padding: 0;
  list-style: none;
}

.chips li {
  background: var(--chip);
  color: var(--ink);
  border-radius: 999px;
  padding: 0.35rem 0.7rem;
  font-size: 0.86rem;
}

.samples { display: grid; gap: 0.75rem; }

.samples figure {
  margin: 0;
  display: grid;
  gap: 0.3rem;
}

.samples figcaption {
  font-size: 0.88rem;
  color: var(--ink);
  font-weight: 600;
}

.samples audio { width: 100%; height: 40px; }

.section { padding: 4.2rem 0; }

.section-head {
  max-width: 40rem;
  margin-bottom: 1.6rem;
}

.section-head p { margin: 0; }

.cards, .guides, .uses, .steps {
  display: grid;
  gap: 0.9rem;
}

.card, .guide-card, .use, .step, .faq-item, .final, .note, .related {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.card, .use, .step, .faq-item {
  padding: 1.15rem 1.15rem 1.2rem;
}

.card p, .use p, .step p, .faq-item p { margin: 0; }

.card .num, .step .num {
  display: block;
  color: var(--brand);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.45rem;
}

.langs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1.2rem 0 0;
  padding: 0;
  list-style: none;
}

.langs li {
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 999px;
  padding: 0.45rem 0.8rem;
  color: var(--ink);
  font-size: 0.92rem;
}

.after { margin-top: 1.2rem; }

.guide-card {
  padding: 1.15rem 1.2rem 1.2rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  color: inherit;
  text-decoration: none;
}

.guide-card:hover { border-color: var(--brand); }

.guide-card strong {
  color: var(--ink);
  letter-spacing: -0.02em;
  font-size: 1.12rem;
}

.guide-card span { color: var(--muted); font-size: 0.95rem; }

.guide-card em {
  margin-top: auto;
  font-style: normal;
  color: var(--brand);
  font-weight: 700;
  font-size: 0.92rem;
}

.faq-item h3 { font-size: 1.08rem; }

.more {
  display: inline-block;
  margin-top: 0.7rem;
  font-weight: 700;
}

.final {
  padding: 1.5rem 1.2rem;
  display: grid;
  gap: 0.8rem;
  align-items: center;
}

.final img {
  width: 72px;
  height: 72px;
  border-radius: 18px;
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 2rem 0 6.5rem;
}

.footer-grid {
  display: grid;
  gap: 1.4rem;
}

.site-footer .label {
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 0.5rem;
  font-weight: 700;
}

.prose .faq-item { margin-top: 0.75rem; }

.prose .guide-cta h2 {
  margin: 0 0 0.35rem;
  font-size: 1.25rem;
}

.site-footer ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-footer li { margin: 0.3rem 0; }

.site-footer a { color: var(--ink); text-decoration: none; }

.site-footer a:hover { color: var(--brand); text-decoration: underline; }

.legal {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 1.2rem 0 0;
}

.sticky-cta {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 3;
  display: flex;
  gap: 0.7rem;
  align-items: center;
  justify-content: space-between;
  padding: 0.7rem 1rem calc(0.7rem + env(safe-area-inset-bottom));
  background: var(--header);
  border-top: 1px solid var(--line);
  transform: translateY(110%);
  transition: transform 180ms ease;
}

.sticky-cta.is-visible { transform: translateY(0); }

.sticky-cta strong {
  color: var(--ink);
  font-size: 0.95rem;
  letter-spacing: -0.02em;
}

.sticky-cta span {
  display: block;
  color: var(--muted);
  font-size: 0.8rem;
}

.article-hero { padding: 2rem 0 0.5rem; }

.crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  list-style: none;
  margin: 0 0 1rem;
  padding: 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.crumbs a { color: var(--muted); }

.prose {
  max-width: 44rem;
  padding-bottom: 1rem;
}

.prose h2 { margin-top: 2.2rem; }

.prose h3 { margin-top: 1.3rem; }

.prose li { margin: 0.35rem 0; }

.prose ol, .prose ul { padding-left: 1.2rem; }

.answer {
  border-left: 3px solid var(--brand);
  padding: 0.2rem 0 0.2rem 1rem;
  margin: 1rem 0 0;
  color: var(--ink);
}

.note, .related, .guide-cta {
  margin: 1.4rem 0;
  padding: 1rem 1.1rem;
}

.guide-cta {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  display: grid;
  gap: 0.7rem;
}

.guide-cta img {
  width: 56px;
  height: 56px;
  border-radius: 14px;
}

.toc {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem 0.8rem;
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
}

.toc a { font-size: 0.92rem; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
  margin: 1rem 0;
  display: block;
  overflow-x: auto;
}

th, td {
  text-align: left;
  padding: 0.65rem 0.5rem;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

th { color: var(--ink); font-size: 0.82rem; letter-spacing: 0.04em; }

@media (min-width: 840px) {
  .nav-toggle { display: none; }

  .nav {
    position: static;
    display: flex;
    align-items: center;
    gap: 0.3rem;
    margin-left: auto;
    border: 0;
    padding: 0;
    background: transparent;
  }

  .nav a { padding: 0.4rem 0.65rem; font-size: 0.95rem; }

  .nav .btn { margin: 0 0 0 0.4rem; min-height: 42px; }

  .hero { padding: 4.5rem 0 5rem; }

  .hero-grid { grid-template-columns: 1.05fr 0.95fr; gap: 3rem; }

  .cards, .guides { grid-template-columns: repeat(3, 1fr); }

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

  .steps { grid-template-columns: repeat(4, 1fr); }

  .final {
    grid-template-columns: auto 1fr auto;
    padding: 1.6rem 1.5rem;
  }

  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; }

  .site-footer { padding-bottom: 2.5rem; }

  .sticky-cta { display: none; }

  .guide-cta {
    grid-template-columns: auto 1fr auto;
    align-items: center;
  }
}

@media (max-width: 839px) {
  .header-inner .btn-desktop { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .sticky-cta { transition: none; }
}