:root {
  --bg: #F2F0ED; --surface: #FFFFFF; --ink: #2A2724; --muted: #67615B; --line: #E2DED8; --soft: #EDEAE5;
  --amber: #F2C14E; --amber-ink: #6E4700; --amber-soft: #FFF3D9; --press: #E6E2DC; --press-ink: #4A443F;
  --font-body: "Noto Sans TC", system-ui, -apple-system, "PingFang TC", "Microsoft JhengHei", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, Menlo, monospace;
  color-scheme: light;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.65 var(--font-body);
  padding: 0 max(16px, env(safe-area-inset-right, 0px)) calc(32px + env(safe-area-inset-bottom, 0px)) max(16px, env(safe-area-inset-left, 0px)); }
a { color: inherit; }
.wrap { max-width: 640px; margin: 0 auto; }
:focus-visible { outline: 3px solid var(--ink); outline-offset: 2px; }
.vh { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* top bar */
.top { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 16px 0 8px; }
.logo { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 900; font-size: 19px; min-height: 48px; }
.logo img { width: 36px; height: 36px; border-radius: 9px; display: block; }
.link-btn { min-height: 48px; display: inline-flex; align-items: center; padding: 0 14px; border-radius: 999px; border: 1.5px solid var(--ink); text-decoration: none; font-weight: 700; font-size: 15px; background: var(--surface); }

/* hero */
.hero { padding: 28px 0 8px; }
.eyebrow { font-size: 14px; color: var(--muted); font-weight: 500; letter-spacing: 0.06em; margin: 0 0 8px; }
h1 { margin: 0; font-size: clamp(30px, 8.4vw, 44px); line-height: 1.22; font-weight: 900; text-wrap: balance; }
.lead { margin: 14px 0 0; font-size: 17px; color: #47423D; max-width: 34em; }
.cta { display: grid; gap: 10px; margin: 24px 0 0; }
.btn { min-height: 56px; border-radius: 14px; display: flex; align-items: center; justify-content: center; gap: 10px; text-decoration: none; font-weight: 700; font-size: 18px; padding: 0 20px; border: 1.5px solid var(--ink); transition: background-color 0.1s; -webkit-tap-highlight-color: transparent; }
.btn.primary { background: var(--ink); color: #fff; }
.btn.primary svg { color: var(--amber); }
.btn.primary:active { background: var(--press-ink); }
.btn.secondary { background: var(--surface); color: var(--ink); font-size: 16px; min-height: 52px; }
.btn.secondary:active, .link-btn:active { background: var(--press); }
.btn svg { width: 24px; height: 24px; flex: none; }
.trust { margin: 14px 0 0; display: flex; flex-wrap: wrap; gap: 6px 14px; font-size: 14px; color: var(--muted); list-style: none; padding: 0; }
.trust li { display: inline-flex; align-items: center; gap: 6px; }
.trust li::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--ink); opacity: 0.55; }
@media (min-width: 560px) { .cta { grid-template-columns: 1.3fr 1fr; } }

/* sections */
section { margin-top: 44px; }
h2 { font-size: 22px; font-weight: 900; margin: 0 0 14px; line-height: 1.35; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: 16px; padding: 18px; }
.story { border-left: 4px solid var(--amber); }
.story p { margin: 0; font-size: 17px; }
.story .by { margin-top: 10px; font-size: 14px; color: var(--muted); }

.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; counter-reset: s; }
.steps li { counter-increment: s; display: grid; grid-template-columns: 40px minmax(0, 1fr); gap: 14px; align-items: start; }
.steps li::before { content: counter(s); width: 40px; height: 40px; border-radius: 50%; background: var(--ink); color: #fff; font: 500 17px var(--font-mono); display: grid; place-items: center; }
.steps b { display: block; font-size: 17px; }
.steps span { color: var(--muted); font-size: 15px; }

.features { display: grid; gap: 10px; }
@media (min-width: 560px) { .features { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.feature { display: grid; grid-template-columns: 44px minmax(0, 1fr); gap: 14px; align-items: start; }
.feature .ic { width: 44px; height: 52px; border-radius: 4px 12px 4px 4px; background: var(--soft); display: grid; place-items: center; }
.feature .ic svg { width: 24px; height: 24px; }
.feature h3 { margin: 0 0 2px; font-size: 17px; }
.feature p { margin: 0; color: var(--muted); font-size: 15px; }

.install { display: grid; gap: 10px; }
.install h3 { margin: 0 0 6px; font-size: 16px; }
.install ol { margin: 0; padding-left: 1.3em; color: #47423D; font-size: 15px; }

/* FAQ: plain rows on the page background, split by hairlines */
details { border-bottom: 1px solid #D9D4CD; }
h2 + details { border-top: 1px solid #D9D4CD; }
summary { min-height: 60px; padding: 0 4px; display: flex; align-items: center; justify-content: space-between; gap: 12px; cursor: pointer; font-weight: 700; list-style: none; }
summary::-webkit-details-marker { display: none; }
summary::after { content: ""; flex: none; width: 9px; height: 9px; border-right: 2.5px solid currentColor; border-bottom: 2.5px solid currentColor; transform: rotate(45deg) translate(-2px, -2px); transition: transform 0.18s; }
details[open] summary::after { transform: rotate(-135deg) translate(-2px, -2px); }
details p { margin: 0; padding: 0 4px 18px; color: #47423D; font-size: 15px; }

.closing { text-align: center; }
.closing .cta { max-width: 420px; margin-left: auto; margin-right: auto; grid-template-columns: 1fr; }
footer { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--line); font-size: 13.5px; color: var(--muted); display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }

/* language menu: one compact button, the list opens below it (scales to any number of languages) */
.top-right { display: flex; align-items: center; gap: 8px; flex: none; position: relative; }
.link-btn { white-space: nowrap; }
.langmenu { position: static; background: none; border: 0; border-radius: 0; } /* not an FAQ box */
.langmenu summary { list-style: none; min-height: 48px; display: inline-flex; align-items: center; gap: 6px; padding: 0 12px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); cursor: pointer; font-size: 14px; font-weight: 700; white-space: nowrap; -webkit-tap-highlight-color: transparent; }
.langmenu summary::-webkit-details-marker { display: none; }
.langmenu summary::after { display: none; }
.langmenu summary svg { width: 18px; height: 18px; flex: none; }
.langmenu summary .chev { width: 7px; height: 7px; border-right: 2px solid currentColor; border-bottom: 2px solid currentColor; transform: rotate(45deg) translate(-1px, -1px); }
.langmenu[open] summary { background: var(--soft); }
.langmenu summary:active { background: var(--press); }
/* the globe button sits at the far right; its list opens straight below it */
.langmenu nav { position: absolute; right: 0; top: calc(100% + 6px); z-index: 10; width: 190px; background: var(--surface); border: 1px solid var(--line); border-radius: 14px; box-shadow: 0 10px 28px rgba(42, 39, 36, 0.16); padding: 6px; }
.langs { display: grid; gap: 2px; margin: 0; padding: 0; list-style: none; }
.langs a { min-height: 48px; display: flex; align-items: center; padding: 0 12px; border-radius: 10px; text-decoration: none; font-size: 15px; font-weight: 500; color: var(--ink); white-space: nowrap; }
.langs a[aria-current="page"] { font-weight: 700; background: var(--soft); }
.langs a[aria-current="page"]::after { content: "✓"; margin-left: auto; padding-left: 12px; }
.langs a:active { background: var(--press); }
.top { gap: 8px; }
.logo { min-width: 0; }
@media (max-width: 400px) { .top .link-btn { display: none; } }

html[lang="en"] body { font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", var(--font-body); }

/* language suggestion bar */
.langhint { position: sticky; top: 0; z-index: 5; margin: 0 calc(-1 * max(16px, env(safe-area-inset-left, 0px))); padding: 6px max(16px, env(safe-area-inset-right, 0px)) 6px max(16px, env(safe-area-inset-left, 0px));
  display: flex; align-items: center; gap: 8px; background: var(--ink); color: #fff; font-size: 15px; }
.langhint span { flex: 1; min-width: 0; }
.langhint a { min-height: 44px; display: inline-flex; align-items: center; padding: 0 14px; border-radius: 999px; background: #fff; color: var(--ink); font-weight: 700; text-decoration: none; }
.langhint button { width: 44px; height: 44px; border: 0; background: transparent; color: #fff; font-size: 22px; cursor: pointer; }

html[lang="zh-Hans"] body { font-family: "Noto Sans SC", var(--font-body); }