/* AirBoard — 845.Lab  (navy × white) */
:root {
  --navy: #0B1B3A;
  --navy-2: #102650;
  --navy-3: #1A3366;
  --sky: #7DD3FC;
  --sky-soft: #E6F6FE;
  --ink: #0B1B3A;
  --text: #2A3550;
  --muted: #647089;
  --line: rgba(11, 27, 58, .10);
  --mist: #F4F7FB;
  --paper: #FFFFFF;
  --radius: 22px;
  --shadow: 0 30px 80px -30px rgba(11, 27, 58, .45), 0 12px 30px -18px rgba(11, 27, 58, .35);
  --wrap: 1160px;
  --gutter: clamp(16px, 4vw, 40px);
  --sans: "Inter", "Noto Sans JP", -apple-system, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Segoe UI", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 84px; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.85;
  font-feature-settings: "palt";
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
html[lang="en"] body { line-height: 1.7; font-feature-settings: normal; }
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
h1, h2, h3 { color: var(--ink); margin: 0; letter-spacing: .01em; line-height: 1.3; text-wrap: balance; }
html[lang="ja"] h1, html[lang="ja"] h2, html[lang="ja"] h3 { word-break: auto-phrase; }
p { margin: 0; text-wrap: pretty; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 var(--gutter); }
.eyebrow {
  display: inline-block;
  font-size: 12px; font-weight: 600; letter-spacing: .22em; text-transform: uppercase;
  color: var(--navy-3);
}
.on-navy .eyebrow { color: var(--sky); }

/* ---------- header ---------- */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 50;
  transition: background .35s ease, box-shadow .35s ease, color .35s ease;
  color: #fff;
}
.site-header .wrap { display: flex; align-items: center; gap: 24px; height: 72px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.brand img { height: 22px; width: auto; }
.brand .logo-navy { display: none; }
.nav { margin-left: auto; display: flex; align-items: center; gap: 28px; font-size: 14px; }
.nav a { text-decoration: none; opacity: .82; transition: opacity .2s; }
.nav a:hover { opacity: 1; }
.nav .lang {
  border: 1px solid currentColor; border-radius: 999px; padding: 4px 12px; font-size: 12px; letter-spacing: .08em; opacity: .7;
}
.site-header.solid {
  background: rgba(255, 255, 255, .86);
  -webkit-backdrop-filter: saturate(160%) blur(16px); backdrop-filter: saturate(160%) blur(16px);
  box-shadow: 0 1px 0 var(--line);
  color: var(--ink);
}
.site-header.solid .logo-white { display: none; }
.site-header.solid .logo-navy { display: block; }
.site-header.plain { position: sticky; background: rgba(255,255,255,.92); color: var(--ink); box-shadow: 0 1px 0 var(--line); }
.site-header.plain .logo-white { display: none; }
.site-header.plain .logo-navy { display: block; }
@media (max-width: 720px) {
  .nav a:not(.lang) { display: none; }
}

/* ---------- buttons ---------- */
.stores { display: flex; flex-wrap: wrap; gap: 12px; }
.btn {
  display: inline-flex; align-items: center; gap: 12px;
  min-height: 54px; padding: 8px 22px 8px 18px;
  border-radius: 14px; text-decoration: none;
  border: 1px solid rgba(255, 255, 255, .28);
  color: #fff; background: rgba(255, 255, 255, .04);
  transition: transform .2s ease, background .2s ease, border-color .2s ease;
}
.btn:hover { transform: translateY(-2px); border-color: rgba(255, 255, 255, .6); background: rgba(255, 255, 255, .08); }
.btn.primary { background: #fff; color: var(--navy); border-color: #fff; }
.btn.primary:hover { background: var(--sky-soft); }
.btn svg { width: 22px; height: 22px; flex: none; }
.btn span { display: flex; flex-direction: column; line-height: 1.2; }
.btn small { font-size: 11px; letter-spacing: .06em; opacity: .7; }
.btn b { font-size: 16px; font-weight: 700; letter-spacing: .01em; }
.btn.soon { opacity: .55; pointer-events: none; }
.btn.dark { color: var(--navy); border-color: var(--line); background: #fff; }
.btn.dark:hover { border-color: var(--navy-3); background: #fff; }
.btn.dark.primary { background: var(--navy); color: #fff; border-color: var(--navy); }

/* ---------- hero ---------- */
.hero {
  position: relative; overflow: hidden; color: #fff;
  background:
    radial-gradient(900px 520px at 85% 10%, rgba(125, 211, 252, .20), transparent 60%),
    radial-gradient(700px 500px at 0% 100%, rgba(26, 51, 102, .9), transparent 70%),
    linear-gradient(180deg, #0A1834 0%, var(--navy) 60%, #0D2045 100%);
  padding: 150px 0 0;
}
.hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.045) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse at 60% 30%, #000 20%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse at 60% 30%, #000 20%, transparent 75%);
}
.hero .wrap { position: relative; display: grid; grid-template-columns: 1.02fr 1fr; gap: 48px; align-items: end; }
.hero-copy { padding-bottom: 120px; }
.hero h1 {
  color: #fff; font-weight: 900;
  font-size: clamp(44px, 6.4vw, 84px); line-height: 1.12; letter-spacing: .01em;
  margin: 22px 0 26px;
}
html[lang="en"] .hero h1 { font-weight: 800; letter-spacing: -.02em; line-height: 1.02; }
.hero h1 em { font-style: normal; color: var(--sky); }
.hero .lead { color: rgba(255, 255, 255, .78); font-size: clamp(16px, 1.5vw, 18px); max-width: 30em; margin-bottom: 36px; }
.hero .note { margin-top: 18px; font-size: 13px; color: rgba(255, 255, 255, .55); }

.stage { position: relative; height: 640px; }
.stage .pc {
  position: absolute; left: 18%; top: 44px; width: 128%;
  border-radius: 14px; overflow: hidden;
  box-shadow: 0 40px 120px -30px rgba(0, 0, 0, .7), 0 0 0 1px rgba(255, 255, 255, .08);
}
.stage .phone { position: absolute; left: -2%; bottom: -40px; width: 268px; }

/* phone frame drawn in CSS; the screenshot starts just below the camera island */
.phone {
  position: relative;
  background: #05080F;
  border-radius: 52px 52px 0 0;
  padding: 12px 12px 0;
  box-shadow: 0 50px 100px -30px rgba(0, 0, 0, .75), inset 0 0 0 1.5px rgba(255, 255, 255, .12);
}
.phone .screen { border-radius: 40px 40px 0 0; overflow: hidden; background: var(--mist); }
.phone .screen::before { content: ""; display: block; height: 46px; background: var(--mist); }
.phone::after {
  content: ""; position: absolute; left: 50%; top: 24px; transform: translateX(-50%);
  width: 31%; height: 24px; border-radius: 999px; background: #05080F;
}
.phone.white .screen, .phone.white .screen::before { background-color: #fff; }
.phone.whole { border-radius: 52px; padding-bottom: 12px; }
.phone.whole .screen { border-radius: 40px; }
.phone.whole .screen::after { content: ""; display: block; height: 26px; background: #fff; }

/* ---------- trust strip ---------- */
.strip { background: var(--navy); color: rgba(255, 255, 255, .7); border-top: 1px solid rgba(255, 255, 255, .08); }
.strip .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px 32px; padding-top: 22px; padding-bottom: 22px; font-size: 13px; letter-spacing: .06em; }
.strip span { display: inline-flex; align-items: center; gap: 10px; }
.strip span::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--sky); }

/* ---------- sections ---------- */
section { position: relative; }
.section { padding: clamp(88px, 11vw, 150px) 0; }
.section-head { max-width: 760px; margin-bottom: clamp(48px, 6vw, 80px); }
.section-head h2 { font-size: clamp(30px, 3.8vw, 48px); font-weight: 800; margin: 16px 0 20px; }
html[lang="en"] .section-head h2 { letter-spacing: -.015em; }
.section-head p { color: var(--muted); font-size: 17px; }
.center { text-align: center; margin-left: auto; margin-right: auto; }

.principles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border-top: 1px solid var(--line); }
.principle { padding: 36px 32px 8px 0; }
.principle + .principle { padding-left: 32px; border-left: 1px solid var(--line); }
.principle .num { font-size: 13px; font-weight: 600; color: var(--navy-3); letter-spacing: .16em; }
.principle h3 { font-size: 21px; font-weight: 700; margin: 18px 0 12px; }
.principle p { color: var(--muted); font-size: 15px; }

/* feature rows */
.features { background: var(--mist); }
.feature { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(40px, 7vw, 110px); align-items: center; }
.feature + .feature { margin-top: clamp(96px, 12vw, 160px); }
.feature.flip .feature-media { order: 2; }
.feature-media { display: flex; justify-content: center; position: relative; }
.feature-media::before {
  content: ""; position: absolute; inset: 8% 6% 0; border-radius: 40px;
  background: linear-gradient(160deg, #fff, rgba(255,255,255,0));
  border: 1px solid rgba(11,27,58,.06);
}
.feature-media .phone { width: min(330px, 78vw); max-height: 600px; overflow: hidden; }
.feature-media .phone.cut { mask-image: linear-gradient(#000 82%, transparent); -webkit-mask-image: linear-gradient(#000 82%, transparent); }
.feature h3 { font-size: clamp(28px, 3.2vw, 40px); font-weight: 800; margin: 16px 0 22px; }
html[lang="en"] .feature h3 { letter-spacing: -.015em; }
.feature p { color: var(--muted); font-size: 16px; }
.ticks { list-style: none; padding: 0; margin: 28px 0 0; display: grid; gap: 12px; }
.ticks li { display: flex; gap: 14px; align-items: baseline; color: var(--text); font-size: 15px; }
.ticks li::before {
  content: ""; flex: none; width: 18px; height: 18px; border-radius: 50%; transform: translateY(3px);
  background: var(--navy) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'%3E%3Cpath d='M5.5 10.5l3 3 6-7' fill='none' stroke='%237DD3FC' stroke-width='2.2' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / 14px no-repeat;
}

/* save-to illustration (built from the app's own strings) */
.sheet-stack { position: relative; width: min(400px, 88vw); padding: 40px 0 70px; }
.sheet {
  position: relative; background: #fff; border-radius: 28px; padding: 14px 22px 18px;
  box-shadow: var(--shadow); border: 1px solid rgba(11,27,58,.06);
}
.sheet-grab { width: 40px; height: 4px; border-radius: 4px; background: #D5DBE6; margin: 0 auto 16px; }
.sheet-title { font-size: 22px; font-weight: 700; color: var(--ink); }
.sheet-path { font-size: 12px; color: var(--muted); margin: 4px 0 12px; word-break: break-all; }
.sheet-row {
  display: flex; gap: 14px; align-items: center; padding: 14px 12px; border-radius: 14px;
  font-size: 15px; color: var(--ink); line-height: 1.4;
}
.sheet-row svg { width: 22px; height: 22px; flex: none; color: var(--navy-3); }
.sheet-row span { display: flex; flex-direction: column; }
.sheet-row small { font-size: 12px; color: var(--muted); }
.sheet-row.on { background: #E8EEFB; }
.toast {
  position: absolute; right: -6%; bottom: 0; display: flex; align-items: center; gap: 12px;
  background: var(--navy); color: #fff; border-radius: 18px; padding: 14px 18px;
  box-shadow: 0 30px 60px -20px rgba(11,27,58,.6); font-size: 14px; line-height: 1.35;
}
.toast svg { width: 22px; height: 22px; flex: none; color: var(--sky); }
.toast span { display: flex; flex-direction: column; }
.toast small { color: rgba(255,255,255,.6); font-size: 12px; }
.toast em { font-style: normal; color: var(--sky); font-weight: 600; margin-left: 10px; white-space: nowrap; }
@media (max-width: 560px) { .toast { right: 0; left: 8%; } }

/* PC band */
.pc-band { background: var(--navy); color: rgba(255,255,255,.78); overflow: hidden; }
.pc-band h2 { color: #fff; }
.pc-band .section-head p { color: rgba(255,255,255,.7); }
.pc-grid { display: grid; grid-template-columns: .8fr 1.2fr; gap: clamp(40px, 6vw, 90px); align-items: center; }
.pc-shot { border-radius: 14px; overflow: hidden; box-shadow: 0 50px 120px -40px rgba(0,0,0,.8), 0 0 0 1px rgba(255,255,255,.08); }
.keys { display: grid; gap: 18px; margin-top: 32px; }
.key { display: flex; gap: 18px; align-items: flex-start; }
.key kbd {
  flex: none; min-width: 74px; text-align: center; font: 600 13px/1 var(--sans); letter-spacing: .04em;
  padding: 10px 12px; border-radius: 10px; color: #fff;
  background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.18); box-shadow: inset 0 -2px 0 rgba(255,255,255,.08);
}
.key p { font-size: 15px; padding-top: 4px; }

/* steps */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; counter-reset: s; }
.step { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 36px 32px 34px; }
.step .n { font-size: 56px; font-weight: 800; line-height: 1; color: transparent; -webkit-text-stroke: 1.5px var(--navy-3); letter-spacing: -.02em; }
.step h3 { font-size: 20px; font-weight: 700; margin: 26px 0 10px; }
.step p { color: var(--muted); font-size: 15px; }

/* platforms */
.platforms { background: var(--mist); }
.plats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.plat {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px 28px; display: flex; flex-direction: column; gap: 6px; text-decoration: none;
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
a.plat:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: transparent; }
.plat .os { font-size: 13px; letter-spacing: .12em; text-transform: uppercase; color: var(--muted); font-weight: 600; }
.plat h3 { font-size: 22px; font-weight: 700; }
.plat .meta { font-size: 14px; color: var(--muted); margin-top: 6px; }
.plat .go { margin-top: auto; padding-top: 26px; font-size: 14px; font-weight: 600; color: var(--navy-3); display: inline-flex; gap: 8px; align-items: center; }
.plat .go::after { content: "→"; transition: transform .2s; }
a.plat:hover .go::after { transform: translateX(4px); }
.plat.soon .go { color: var(--muted); }
.plat.soon .go::after { content: ""; }
.pricing-note { margin-top: 28px; font-size: 14px; color: var(--muted); }
.guide-grid { grid-template-columns: repeat(3, 1fr); }
.guide-grid .plat h3 { font-size: 19px; }

/* privacy band */
.privacy-band { background: linear-gradient(180deg, var(--navy) 0%, #0A1834 100%); color: rgba(255,255,255,.78); text-align: center; }
.privacy-band h2 { color: #fff; font-size: clamp(30px, 4vw, 52px); font-weight: 800; margin: 18px auto 24px; max-width: 16em; }
.privacy-band p { max-width: 40em; margin: 0 auto; }
.privacy-band .link { display: inline-block; margin-top: 30px; color: var(--sky); text-decoration: none; border-bottom: 1px solid rgba(125,211,252,.4); padding-bottom: 2px; font-size: 15px; }

/* FAQ */
.faq { max-width: 820px; margin: 0 auto; border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  list-style: none; cursor: pointer; padding: 26px 48px 26px 0; position: relative;
  font-size: 17px; font-weight: 600; color: var(--ink);
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: ""; position: absolute; right: 6px; top: 50%; width: 12px; height: 12px; margin-top: -8px;
  border-right: 1.5px solid var(--navy-3); border-bottom: 1.5px solid var(--navy-3); transform: rotate(45deg);
  transition: transform .25s ease;
}
.faq details[open] summary::after { transform: rotate(-135deg); margin-top: -2px; }
.faq .a { padding: 0 48px 28px 0; color: var(--muted); font-size: 15px; }

/* CTA + footer */
.cta { text-align: center; }
.cta img.icon { width: 88px; height: 88px; margin: 0 auto 28px; border-radius: 22px; box-shadow: var(--shadow); }
.cta h2 { font-size: clamp(30px, 4vw, 48px); font-weight: 800; margin-bottom: 18px; }
.cta p { color: var(--muted); margin-bottom: 36px; }
.cta .stores { justify-content: center; }

.site-footer { background: #081328; color: rgba(255,255,255,.6); font-size: 14px; }
.site-footer .wrap { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; padding-top: 72px; padding-bottom: 40px; }
.site-footer img { height: 22px; width: auto; margin-bottom: 18px; }
.site-footer h4 { color: #fff; font-size: 12px; letter-spacing: .18em; text-transform: uppercase; margin: 0 0 16px; font-weight: 600; }
.site-footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.site-footer a { text-decoration: none; }
.site-footer a:hover { color: #fff; }
.site-footer .legal { grid-column: 1 / -1; border-top: 1px solid rgba(255,255,255,.08); padding-top: 26px; font-size: 12px; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

/* reveal (only when JS is on) */
.js .reveal { opacity: 0; transform: translateY(24px); transition: opacity .9s cubic-bezier(.2,.7,.2,1), transform .9s cubic-bezier(.2,.7,.2,1); }
.js .reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .reveal { opacity: 1; transform: none; transition: none; }
  .btn, .plat { transition: none; }
}

/* ---------- document pages (privacy) ---------- */
.doc { padding: 72px 0 120px; }
.doc .wrap { max-width: 820px; }
.doc h1 { font-size: clamp(32px, 4vw, 44px); font-weight: 800; margin: 14px 0 12px; }
.doc .updated { color: var(--muted); font-size: 14px; margin-bottom: 40px; }
.doc .toc { display: flex; gap: 10px; margin-bottom: 48px; flex-wrap: wrap; }
.doc .toc a { font-size: 13px; text-decoration: none; border: 1px solid var(--line); border-radius: 999px; padding: 6px 14px; }
.doc .toc a:hover { border-color: var(--navy-3); }
.doc article h2 { font-size: 26px; font-weight: 800; margin: 72px 0 20px; padding-top: 8px; }
.doc article > h2:first-child { margin-top: 0; }
.doc article h3 { font-size: 18px; font-weight: 700; margin: 40px 0 12px; padding-left: 14px; border-left: 3px solid var(--sky); }
.doc article p, .doc article li { font-size: 15.5px; }
.doc article p { margin: 0 0 14px; }
.doc article ul { padding-left: 1.3em; margin: 0 0 16px; }
.doc article li { margin: 4px 0; }
.doc article a { color: var(--navy-3); word-break: break-all; }
.doc article hr { border: 0; border-top: 1px solid var(--line); margin: 80px 0 0; }

/* ---------- responsive ---------- */
@media (max-width: 980px) {
  .hero { padding-top: 120px; }
  .hero .wrap { grid-template-columns: 1fr; gap: 0; }
  .hero-copy { padding-bottom: 56px; }
  .stage { height: 440px; }
  .stage .pc { left: 26%; width: 110%; top: 0; }
  .stage .phone { left: 0; width: 230px; bottom: -30px; }
  .principles { grid-template-columns: 1fr; }
  .principle, .principle + .principle { padding: 30px 0 24px; border-left: 0; border-bottom: 1px solid var(--line); }
  .feature, .pc-grid { grid-template-columns: 1fr; }
  .feature.flip .feature-media { order: 0; }
  .steps { grid-template-columns: 1fr; }
  .plats { grid-template-columns: 1fr 1fr; }
  .site-footer .wrap { grid-template-columns: 1fr 1fr; }
  .site-footer .wrap > div:first-child { grid-column: 1 / -1; }
}
@media (max-width: 560px) {
  .stage { height: 380px; }
  .stage .phone { width: 196px; }
  .stage .pc { left: 30%; width: 140%; }
  .plats { grid-template-columns: 1fr; }
  .btn { flex: 1 1 100%; }
  .strip .wrap { justify-content: flex-start; }
  .faq summary { font-size: 16px; }
}