:root {
  --text: #2c2c2b;
  --muted: #737373;
  --line: #e8e8e7;
  --soft: #f6f6f5;
  --code: #f4f4f3;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  background: #fff;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", sans-serif;
  font-size: 16px;
  font-weight: 400;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
button, a { font: inherit; }
a { color: inherit; }
button { cursor: pointer; }

.page { width: min(100%, 720px); margin: 0 auto; padding: 16px 24px 32px; }
.page-header { display: flex; min-height: 44px; align-items: center; gap: 14px; padding-bottom: 8px; border-bottom: 1px solid var(--line); color: var(--muted); }
.page-header a { display: inline-flex; min-height: 44px; align-items: center; text-decoration: none; }
.page-header a:hover, .instagram-link:hover { text-decoration: underline; text-underline-offset: 4px; }
.page-header span { white-space: nowrap; }

article { padding-top: 24px; }
h1, h2, p { margin-top: 0; }
h1 { margin-bottom: 16px; font-size: 28px; font-weight: 700; letter-spacing: -0.035em; line-height: 1.35; }
.intro { margin-bottom: 36px; }
.intro p { max-width: 620px; margin-bottom: 0; }
.subtitle { margin-bottom: 16px !important; color: #4a4a49; }

.step { margin-bottom: 36px; }
.step h2 { margin-bottom: 16px; font-size: 20px; font-weight: 600; letter-spacing: -0.02em; line-height: 1.45; }
.step h2 span { margin-right: 8px; font-weight: 400; }
.step h2 em { font-style: normal; }
.step > p { margin-bottom: 16px; }

.platform-switch { display: grid; grid-template-columns: 1fr 1.12fr; gap: 12px; margin-bottom: 12px; }
.platform-switch button { min-height: 48px; border: 1px solid #a9a9a7; border-radius: 6px; color: var(--text); background: #fff; font-weight: 400; }
.platform-switch button[aria-pressed="true"] { border: 1.5px solid var(--text); background: #fafafa; }
.platform-switch button:focus-visible, .setup-copy:focus-visible, .code-strip button:focus-visible, a:focus-visible { outline: 2px solid #3478f6; outline-offset: 3px; }
.setup-status { margin-bottom: 12px !important; }
.setup-copy { display: inline-flex; width: 100%; min-height: 52px; align-items: center; justify-content: center; gap: 9px; border: 0; border-radius: 5px; color: #fff; background: #272727; font-size: 17px; font-weight: 600; }
.setup-copy svg { width: 24px; height: 24px; }
.setup-copy:disabled { cursor: not-allowed; color: #a7a7a6; background: #e8e8e7; }
.registration-note { margin: 12px 0 0 !important; color: var(--muted); font-size: 14px; }

.code-strip { display: flex; min-height: 48px; align-items: center; justify-content: space-between; gap: 14px; margin: 14px 0 16px; padding: 7px 10px 7px 16px; border: 1px solid #dededc; border-radius: 4px; background: var(--code); }
.code-strip code { font-family: inherit; font-size: 16px; }
.code-strip button { min-width: 56px; min-height: 44px; border: 0; border-radius: 4px; color: #555; background: transparent; }
.code-strip button:hover { background: #e9e9e7; }
.reference-callout { margin-top: 24px; padding: 16px; border-radius: 4px; background: var(--soft); }
.reference-callout h2 { margin-bottom: 8px; font-size: 16px; font-weight: 600; line-height: 1.5; }
.reference-callout p { margin-bottom: 0; }
.last-step { margin-bottom: 28px; }
.footnote { margin: 0; color: var(--muted); font-size: 14px; }

footer { margin-top: 24px; color: var(--muted); }
.instagram-link { display: inline-flex; min-height: 44px; align-items: center; }
footer p { min-height: 44px; margin: 2px 0 0; display: flex; align-items: center; }

#copy-toast { position: fixed; right: 18px; bottom: 18px; z-index: 2; max-width: calc(100vw - 36px); padding: 9px 12px; border-radius: 5px; color: #fff; background: #2c2c2b; font-size: 14px; opacity: 0; pointer-events: none; transition: opacity 160ms ease; }
#copy-toast.visible { opacity: 1; }

@media (min-width: 721px) {
  .page { padding: 32px 0 40px; }
  h1 { font-size: 40px; line-height: 1.25; }
  article { padding-top: 28px; }
  .intro { margin-bottom: 40px; }
}

@media (max-width: 374px) {
  .page { padding-right: 20px; padding-left: 20px; }
  .page-header { gap: 10px; }
  .platform-switch { gap: 9px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: 0.01ms !important; }
}