/* Koihop website. Colours follow the app's Ink tokens (Shared/InkTokens.swift). */
:root {
  --ground: #0b0f14;
  --surface: #121821;
  --raised: #18202b;
  --hairline: #232c38;
  --text: #f2f4f7;
  --text2: #b7c0cc;
  --text3: #8a95a5;
  --signal: #4fe3c1;
  --signal-dim: rgba(79, 227, 193, .14);
  --amber: #ffb454;
  --radius: 20px;
  --max: 1120px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "PingFang TC", "Hiragino Sans GB",
          "Microsoft YaHei", "Noto Sans CJK SC", "Helvetica Neue", Arial, sans-serif;
  --mono: "SF Mono", ui-monospace, Menlo, Consolas, monospace;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--ground); color: var(--text); font: 16px/1.65 var(--font); }
a { color: var(--signal); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 20px; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 16px; top: 16px; background: var(--signal); color: var(--ground); padding: 8px 12px; border-radius: 8px; z-index: 10; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 5; background: rgba(11, 15, 20, .82); backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px); border-bottom: 1px solid var(--hairline); }
.site-header .wrap { display: flex; align-items: center; gap: 20px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; letter-spacing: .1em; }
.brand:hover { text-decoration: none; }
.brand img { width: 32px; height: 32px; border-radius: 8px; }
.brand .koi { color: var(--signal); }
.nav { display: flex; gap: 22px; margin-left: auto; font-size: 15px; }
.nav a { color: var(--text2); }
.nav a:hover { color: var(--text); text-decoration: none; }
.lang { font-size: 14px; color: var(--text3); }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 10px; border-radius: 14px; padding: 13px 22px;
  font-weight: 650; font-size: 16px; border: 1px solid transparent; cursor: pointer; }
.btn:hover { text-decoration: none; filter: brightness(1.06); }
.btn-primary { background: var(--signal); color: #04201a; }
.btn-ghost { border-color: var(--hairline); color: var(--text); background: var(--surface); }
.btn-sm { padding: 8px 14px; font-size: 14px; border-radius: 10px; }
.btn svg { width: 20px; height: 20px; }

/* Hero */
.hero { position: relative; overflow: hidden; padding: 72px 0 40px; }
.hero::before { content: ""; position: absolute; inset: -20% -10% auto 40%; height: 720px;
  background: radial-gradient(closest-side, rgba(28, 110, 96, .55), transparent); pointer-events: none; }
.hero .wrap { position: relative; display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; align-items: center; }
.eyebrow { display: inline-flex; gap: 8px; align-items: center; font-size: 13px; letter-spacing: .08em; text-transform: uppercase;
  color: var(--signal); background: var(--signal-dim); border-radius: 999px; padding: 6px 12px; }
h1 { font-size: clamp(34px, 5vw, 56px); line-height: 1.12; margin: 18px 0 16px; letter-spacing: -.01em; }
h1 em { font-style: normal; color: var(--signal); }
.nw { white-space: nowrap; }
.lead { font-size: 19px; color: var(--text2); max-width: 36em; margin: 0 0 28px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.ticks { display: flex; flex-wrap: wrap; gap: 8px 20px; list-style: none; padding: 0; margin: 26px 0 0; color: var(--text2); font-size: 15px; }
.ticks li::before { content: "✓"; color: var(--signal); margin-right: 8px; font-weight: 700; }
.phone { position: relative; width: min(330px, 100%); margin: 0 auto; border-radius: 48px; padding: 10px; background: #1b222c;
  box-shadow: 0 40px 120px rgba(0, 0, 0, .55), 0 0 0 1px #2c3644 inset; }
.phone img { border-radius: 40px; }

/* Sections */
section { padding: 72px 0; }
.section-head { max-width: 720px; margin: 0 0 36px; }
.section-head h2 { font-size: clamp(26px, 3.4vw, 38px); line-height: 1.2; margin: 0 0 12px; }
.section-head p { color: var(--text2); margin: 0; font-size: 17px; }
.kicker { font-size: 13px; letter-spacing: .1em; text-transform: uppercase; color: var(--signal); font-weight: 650; }
.alt { background: linear-gradient(180deg, transparent, rgba(18, 24, 33, .7) 12%, rgba(18, 24, 33, .7) 88%, transparent); }

/* Feature / USP grid */
.grid { display: grid; gap: 16px; grid-template-columns: repeat(3, 1fr); }
.card { background: var(--surface); border: 1px solid var(--hairline); border-radius: var(--radius); padding: 24px; }
.card h3 { margin: 6px 0 8px; font-size: 19px; }
.card p { margin: 0; color: var(--text2); font-size: 15.5px; }
.card .icon { width: 40px; height: 40px; border-radius: 12px; display: grid; place-items: center; background: var(--signal-dim); color: var(--signal); font-size: 20px; }
.protocols { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; }
.protocols span { font: 600 13px/1 var(--mono); padding: 8px 10px; border-radius: 8px; background: var(--raised); border: 1px solid var(--hairline); color: var(--text2); }

/* Download */
.download { display: grid; grid-template-columns: 1fr auto; gap: 32px; align-items: center; background: var(--surface);
  border: 1px solid var(--hairline); border-radius: 28px; padding: 36px; }
.download h2 { margin: 0 0 8px; font-size: clamp(24px, 3vw, 32px); }
.download p { margin: 0 0 20px; color: var(--text2); }
.qr { width: 148px; padding: 10px; background: #fff; border-radius: 16px; }
.qr-cap { font-size: 13px; color: var(--text3); text-align: center; margin-top: 8px; }
.fine { font-size: 13.5px; color: var(--text3); margin-top: 14px; }

/* Screenshots */
.shots { display: flex; gap: 18px; overflow-x: auto; scroll-snap-type: x mandatory; padding-bottom: 12px; }
.shots figure { margin: 0; flex: 0 0 240px; scroll-snap-align: start; }
.shots img { border-radius: 22px; border: 1px solid var(--hairline); }
.shots figcaption { font-size: 14px; color: var(--text3); margin-top: 10px; }

/* Steps */
.steps { counter-reset: s; display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; list-style: none; padding: 0; margin: 0; }
.steps li { counter-increment: s; background: var(--surface); border: 1px solid var(--hairline); border-radius: var(--radius); padding: 24px; }
.steps li::before { content: counter(s); display: grid; place-items: center; width: 36px; height: 36px; border-radius: 50%;
  background: var(--signal); color: #04201a; font-weight: 800; margin-bottom: 14px; }
.steps h3 { margin: 0 0 6px; font-size: 18px; }
.steps p { margin: 0; color: var(--text2); font-size: 15.5px; }

/* Guides list */
.guide-card { display: flex; flex-direction: column; gap: 8px; color: var(--text); }
.guide-card:hover { text-decoration: none; border-color: #335; }
.guide-card .kw { font: 600 12px/1 var(--mono); color: var(--amber); }
.guide-card .more { margin-top: auto; color: var(--signal); font-size: 15px; }

/* FAQ */
.faq { display: grid; gap: 10px; }
.faq details { background: var(--surface); border: 1px solid var(--hairline); border-radius: 16px; padding: 4px 20px; }
.faq summary { cursor: pointer; list-style: none; padding: 16px 0; font-weight: 650; font-size: 17px; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--signal); font-size: 22px; line-height: 1; }
.faq details[open] summary::after { content: "–"; }
.faq .a { padding: 0 0 18px; color: var(--text2); }
.faq .a p { margin: 0 0 10px; }

/* Final CTA */
.final { text-align: center; padding: 88px 0; background: radial-gradient(60% 80% at 50% 100%, rgba(28, 110, 96, .45), transparent); }
.final h2 { font-size: clamp(28px, 4vw, 44px); margin: 0 0 12px; }
.final p { color: var(--text2); margin: 0 0 26px; font-size: 18px; }

/* Footer */
.site-footer { border-top: 1px solid var(--hairline); padding: 40px 0 56px; color: var(--text3); font-size: 14px; }
.site-footer .wrap { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 24px; }
.site-footer h4 { color: var(--text2); margin: 0 0 10px; font-size: 14px; }
.site-footer ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 6px; }
.site-footer a { color: var(--text3); }
.site-footer a:hover { color: var(--text); }

/* Article (guides, legal) */
.article { max-width: 760px; margin: 0 auto; padding: 48px 20px 72px; }
.crumbs { font-size: 14px; color: var(--text3); margin-bottom: 18px; }
.crumbs a { color: var(--text3); }
.article h1 { font-size: clamp(30px, 4.4vw, 44px); }
.article h2 { font-size: 26px; margin: 44px 0 12px; }
.article h3 { font-size: 19px; margin: 28px 0 8px; }
.article p, .article li { color: var(--text2); }
.article strong { color: var(--text); }
.article ol, .article ul { padding-left: 22px; }
.article li { margin: 6px 0; }
.article code { font: 14px var(--mono); background: var(--raised); border: 1px solid var(--hairline); border-radius: 6px; padding: 1px 6px; color: var(--text); }
.article .lang-title { font-size: clamp(30px, 4.4vw, 44px); margin-top: 72px; padding-top: 32px; border-top: 1px solid var(--hairline); }
.article .meta { color: var(--text3); font-size: 14px; }
.callout { background: var(--surface); border: 1px solid var(--hairline); border-left: 3px solid var(--signal); border-radius: 12px; padding: 16px 18px; margin: 22px 0; }
.callout p { margin: 0; }
.callout.warn { border-left-color: var(--amber); }
.article figure { margin: 26px auto; max-width: 300px; }
.article figure img { border-radius: 22px; border: 1px solid var(--hairline); }
.article figcaption { font-size: 13.5px; color: var(--text3); text-align: center; margin-top: 8px; }
.inline-cta { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; justify-content: space-between; background: var(--surface);
  border: 1px solid var(--hairline); border-radius: 18px; padding: 20px 22px; margin: 36px 0; }
.inline-cta p { margin: 0; color: var(--text); font-weight: 600; }
.related { display: grid; gap: 8px; padding-left: 0; list-style: none; }
.toc { background: var(--surface); border: 1px solid var(--hairline); border-radius: 14px; padding: 14px 20px; margin: 22px 0; font-size: 15px; }
.toc ol { margin: 6px 0 0; }

@media (max-width: 900px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .hero { padding-top: 40px; }
  .grid, .steps { grid-template-columns: 1fr; }
  .download { grid-template-columns: 1fr; }
  .qr-box { display: none; }
  .nav { display: none; }
  .site-footer .wrap { grid-template-columns: 1fr; }
  section { padding: 56px 0; }
}
@media (min-width: 901px) and (max-width: 1080px) { .grid { grid-template-columns: repeat(2, 1fr); } }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }