/* One stylesheet for all three languages. No fonts, scripts or images are
   fetched from anywhere else: a page that loads nothing third-party is fast
   on a hotel wifi in Chengdu, which is where this app gets found. */
:root {
  --ink: #152238;
  --muted: #5c6b80;
  --faint: #8695a8;
  --blue: #0a84ff;
  --blue-dark: #0069d9;
  --line: #e3e9f1;
  --bg: #ffffff;
  --bg-soft: #f5f8fc;
  --radius: 18px;
  --measure: 1080px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 400 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
        "Helvetica Neue", Arial, "Noto Sans", "Noto Sans KR", sans-serif;
  -webkit-font-smoothing: antialiased;
}
.wrap { max-width: var(--measure); margin: 0 auto; padding: 0 24px; }
a { color: var(--blue); }

header.top {
  position: sticky; top: 0; z-index: 10;
  background: rgba(255,255,255,.88);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.top .wrap { display: flex; align-items: center; gap: 16px; height: 62px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 19px; }
.brand svg { width: 30px; height: 30px; }
.top nav { margin-left: auto; display: flex; align-items: center; gap: 20px; }
.top nav a { color: var(--muted); text-decoration: none; font-size: 15px; }
.top nav a:hover { color: var(--ink); }
.langs { display: flex; gap: 8px; font-size: 14px; }
.langs a { color: var(--faint); text-decoration: none; }
.langs a[aria-current="true"] { color: var(--ink); font-weight: 600; }

.btn {
  display: inline-block; background: var(--blue); color: #fff;
  text-decoration: none; font-weight: 600; padding: 15px 30px;
  border-radius: 999px; border: 0; font-size: 17px;
  box-shadow: 0 6px 20px rgba(10,132,255,.28);
}
.btn:hover { background: var(--blue-dark); }
.btn.ghost { background: #fff; color: var(--ink); border: 1px solid var(--line); box-shadow: none; }

section { padding: 84px 0; }
section.soft { background: var(--bg-soft); }
h1 { font-size: clamp(34px, 5.4vw, 56px); line-height: 1.1; letter-spacing: -.02em; margin: 0 0 18px; }
h2 { font-size: clamp(26px, 3.4vw, 36px); line-height: 1.2; letter-spacing: -.01em; margin: 0 0 14px; }
h3 { font-size: 19px; margin: 0 0 6px; }
.lede { font-size: clamp(18px, 2.2vw, 21px); color: var(--muted); margin: 0 0 30px; max-width: 60ch; }
.sub { color: var(--muted); margin: 0 0 42px; max-width: 62ch; }
.center { text-align: center; }
.center .lede, .center .sub { margin-left: auto; margin-right: auto; }

.hero { display: grid; grid-template-columns: 1.05fr .95fr; gap: 56px; align-items: center; }
.hero .fine { font-size: 14px; color: var(--faint); margin-top: 16px; }

.shot {
  border: 1px solid var(--line); border-radius: 26px; background: var(--bg-soft);
  aspect-ratio: 9 / 19.5; display: grid; place-items: center; text-align: center;
  color: var(--faint); font-size: 14px; padding: 20px; max-width: 320px; margin: 0 auto;
}
.shot.wide { aspect-ratio: 16 / 10; max-width: none; }

/* A real screenshot fills the frame the placeholder only outlined, so the
   padding and the centred caption text go with it. */
.shot.filled {
  padding: 0; overflow: hidden; aspect-ratio: auto;
  box-shadow: 0 18px 40px rgba(15, 30, 60, .10);
}
.shot.filled img { display: block; width: 100%; height: auto; }
figure.shot { margin: 0 auto; }
.shot figcaption {
  padding: 12px 16px; font-size: 13px; color: var(--faint);
  background: #fff; border-top: 1px solid var(--line);
}

.grid { display: grid; gap: 22px; }
.g3 { grid-template-columns: repeat(3, 1fr); }
.g4 { grid-template-columns: repeat(4, 1fr); }
.card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.card p { margin: 0; color: var(--muted); font-size: 16px; }
.soft .card { background: #fff; }

.steps { counter-reset: step; display: grid; gap: 18px; }
.step { display: flex; gap: 16px; align-items: flex-start; }
.step .n {
  flex: 0 0 auto; width: 32px; height: 32px; border-radius: 999px;
  background: #e7f0fc; color: var(--blue); font-weight: 700; font-size: 15px;
  display: grid; place-items: center;
}
.step p { margin: 4px 0 0; color: var(--muted); }

.quote { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; }
.quote blockquote { margin: 0 0 16px; font-size: 17px; }
.quote figcaption { color: var(--faint); font-size: 14px; }
.placeholder-note {
  border: 1px dashed #c8b78a; background: #fdf8ec; color: #7a6320;
  border-radius: 12px; padding: 14px 16px; font-size: 14px; margin: 0 0 26px;
}

details { border-bottom: 1px solid var(--line); padding: 18px 0; }
details summary { cursor: pointer; font-weight: 600; list-style: none; }
details summary::-webkit-details-marker { display: none; }
details summary::after { content: "+"; float: right; color: var(--faint); }
details[open] summary::after { content: "\2212"; }
details p { color: var(--muted); margin: 12px 0 0; }

footer { border-top: 1px solid var(--line); padding: 40px 0; color: var(--faint); font-size: 14px; }
footer .wrap { display: flex; gap: 18px; flex-wrap: wrap; align-items: center; }
footer a { color: var(--muted); text-decoration: none; }
footer .sep { margin-left: auto; }

/* Steps beside a screenshot. Was an inline style, which no media query can
   override, so it stayed two columns on a phone and squeezed the steps into a
   column a few words wide. */
.split { grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }

@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; }
  .g3, .g4 { grid-template-columns: 1fr 1fr; }
  .split { grid-template-columns: 1fr; gap: 36px; }
  section { padding: 60px 0; }
  .top nav a.hide-sm { display: none; }
}
@media (max-width: 560px) {
  .g3, .g4 { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

/* ---- Language picker: one round button, panel underneath ---- */
.lang { position: relative; }
.lang-btn {
  width: 38px; height: 38px; border-radius: 999px;
  border: 1px solid var(--line); background: #fff; cursor: pointer;
  display: grid; place-items: center; padding: 0; color: var(--muted);
}
.lang-btn:hover { color: var(--ink); border-color: #cdd8e6; }
.lang-btn svg { width: 20px; height: 20px; }
.lang-panel {
  position: absolute; right: 0; top: 46px; z-index: 20;
  background: #fff; border: 1px solid var(--line); border-radius: 14px;
  box-shadow: 0 14px 40px rgba(21,34,56,.14);
  padding: 8px; width: 268px; max-height: 340px; overflow-y: auto;
  display: none; grid-template-columns: 1fr 1fr; gap: 2px;
}
.lang-panel[data-open="true"] { display: grid; }
.lang-panel a {
  display: block; padding: 8px 10px; border-radius: 9px;
  text-decoration: none; color: var(--ink); font-size: 14px; white-space: nowrap;
}
.lang-panel a:hover { background: var(--bg-soft); }
.lang-panel a[aria-current="true"] { background: #e7f0fc; color: var(--blue); font-weight: 600; }
.lang-panel .soon { color: var(--faint); }

/* Suggestion strip, shown only when the visitor's browser prefers another
   language. Never a redirect: a redirect would send every crawler to one
   page and un-index the rest. */
.lang-hint {
  display: none; background: #eef4fd; border-bottom: 1px solid #d8e6f8;
  font-size: 14px; color: var(--ink);
}
.lang-hint[data-show="true"] { display: block; }
.lang-hint .wrap { display: flex; gap: 12px; align-items: center; padding: 10px 24px; }
.lang-hint a { font-weight: 600; }
.lang-hint button {
  margin-left: auto; background: none; border: 0; color: var(--faint);
  cursor: pointer; font-size: 18px; line-height: 1; padding: 4px 6px;
}