/* Kaitori Base 紹介ページ。
   最初の画面はアプリのアイコンと同じ「深い紺の夜空に青い光」。本文は、アプリの画面と同じ明るい地（#FAF9F5）に濃い文字で、スマートフォンで読みやすくする。
   スマートフォンの幅を先に作り、広い画面で段組みを増やす。外部のライブラリは使わない。 */
:root {
  --navy: #0a1630;
  --navy-deep: #060d1f;
  --blue: #2f7bff;
  --blue-light: #7fb3ff;
  --blue-deep: #1a5fe0;
  --paper: #faf9f5;
  --paper-2: #f0eee6;
  --ink: #141413;
  --ink-2: #6b6960;
  --line: #e2e0d8;
  --on-dark: #ffffff;
  --on-dark-muted: rgba(255, 255, 255, 0.76);
  --radius: 20px;
  --gutter: 16px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", sans-serif;
  line-height: 1.8;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--blue-deep); }
h1, h2, h3 { line-height: 1.35; margin: 0; font-weight: 700; letter-spacing: 0.01em; word-break: keep-all; overflow-wrap: anywhere; }
p { margin: 0; }
strong { font-weight: 700; }

.wrap { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 var(--gutter); }
.wrap.narrow { max-width: 780px; }
.center { text-align: center; }
.sp-only { display: inline; }
@media (min-width: 720px) { .sp-only { display: none; } }

/* ---- ヘッダー（紺の帯。下にスクロールしても付いてくる） ---- */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: rgba(8, 17, 40, 0.82);
  -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--on-dark);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 56px; }
.brand { display: flex; align-items: center; gap: 8px; color: var(--on-dark); text-decoration: none; font-weight: 700; font-size: 18px; letter-spacing: 0.01em; }
.brand img { border-radius: 8px; }
.header-nav { display: none; gap: 24px; }
.header-nav a { color: var(--on-dark-muted); text-decoration: none; font-size: 15px; }
.header-nav a:hover { color: var(--on-dark); }
@media (min-width: 820px) { .header-nav { display: flex; } }

/* ---- ボタン ---- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 52px; padding: 12px 26px; border-radius: 999px;
  font-size: 16px; font-weight: 700; text-decoration: none; text-align: center;
  transition: transform 0.15s ease, filter 0.15s ease, box-shadow 0.15s ease;
}
.btn:hover { filter: brightness(1.06); }
.btn:active { transform: scale(0.98); }
.btn-primary { background: linear-gradient(180deg, #4a8dff, var(--blue-deep)); color: #fff; box-shadow: 0 10px 28px rgba(47, 123, 255, 0.38); }
.btn-ghost { background: rgba(255, 255, 255, 0.1); color: var(--on-dark); border: 1px solid rgba(255, 255, 255, 0.45); }
.btn-small { min-height: 40px; padding: 8px 16px; font-size: 14px; box-shadow: 0 6px 16px rgba(47, 123, 255, 0.3); }
.btn-large { min-height: 58px; padding: 14px 34px; font-size: 18px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.cta-row.center { justify-content: center; }
.cta-row .btn { flex: 1 1 200px; }
@media (min-width: 720px) { .cta-row .btn { flex: 0 0 auto; } }

/* ---- 最初の画面：紺の夜空（アイコンと同じ） ---- */
.hero {
  position: relative; overflow: hidden;
  color: var(--on-dark);
  background: radial-gradient(120% 80% at 50% 100%, #0f2250 0%, var(--navy) 45%, var(--navy-deep) 100%);
  padding: 56px 0 64px;
}
.hero-glow {
  position: absolute; inset: auto; pointer-events: none;
  width: 140vw; height: 140vw; max-width: 1100px; max-height: 1100px;
  left: 50%; top: 50%; transform: translate(-50%, -30%);
  background: radial-gradient(circle, rgba(79, 148, 255, 0.42) 0%, rgba(47, 123, 255, 0.18) 28%, rgba(10, 22, 48, 0) 62%);
  filter: blur(10px);
}
.hero-glow.small { transform: translate(-50%, -50%); opacity: 0.7; }
.hero-stars {
  position: absolute; inset: 0; pointer-events: none; opacity: 0.7;
  background-image:
    radial-gradient(1.5px 1.5px at 12% 18%, rgba(255,255,255,0.9) 50%, transparent 51%),
    radial-gradient(1px 1px at 28% 72%, rgba(255,255,255,0.7) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 44% 32%, rgba(255,255,255,0.8) 50%, transparent 51%),
    radial-gradient(1px 1px at 63% 12%, rgba(255,255,255,0.75) 50%, transparent 51%),
    radial-gradient(2px 2px at 78% 58%, rgba(200,224,255,0.9) 50%, transparent 51%),
    radial-gradient(1px 1px at 88% 26%, rgba(255,255,255,0.7) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 6% 86%, rgba(255,255,255,0.6) 50%, transparent 51%),
    radial-gradient(1px 1px at 55% 90%, rgba(255,255,255,0.6) 50%, transparent 51%),
    radial-gradient(1px 1px at 93% 82%, rgba(255,255,255,0.7) 50%, transparent 51%);
}
.hero-inner { position: relative; display: grid; gap: 40px; align-items: center; }
.eyebrow { color: var(--blue-light); font-weight: 700; font-size: 13px; letter-spacing: 0.08em; margin-bottom: 14px; }
.hero h1 { font-size: clamp(34px, 9vw, 62px); line-height: 1.22; text-shadow: 0 2px 24px rgba(0, 0, 0, 0.45); }
.lead { font-size: clamp(16px, 4.2vw, 19px); color: var(--on-dark-muted); margin-top: 20px; max-width: 34em; }
.note { color: var(--on-dark-muted); font-size: 13px; margin-top: 14px; }
.hero-phone { margin: 0 auto; max-width: 280px; position: relative; }
.hero-phone::before {
  content: ""; position: absolute; inset: -12% -30%; z-index: -1;
  background: radial-gradient(ellipse at center, rgba(79, 148, 255, 0.55) 0%, rgba(79, 148, 255, 0) 60%);
}
@media (min-width: 900px) {
  .hero { padding: 96px 0 104px; }
  .hero-inner { grid-template-columns: 1.15fr 0.85fr; }
  .hero-phone { max-width: 340px; }
  .hero-glow { transform: translate(-50%, -20%); }
}

/* 端末の画面（スクリーンショット）を角の丸い枠に入れる */
.hero-phone img, .phone img {
  border-radius: 38px;
  border: 7px solid rgba(255, 255, 255, 0.16);
  box-shadow: 0 30px 70px rgba(2, 8, 24, 0.55);
  background: #fff;
}
.light .phone img {
  border-color: #1b2338;
  box-shadow: 0 24px 56px rgba(20, 20, 19, 0.22);
}

/* ---- セクション（本文は明るい地） ---- */
.section { padding: 64px 0; }
@media (min-width: 900px) { .section { padding: 100px 0; } }
.light { background: var(--paper); color: var(--ink); }
.light.alt { background: var(--paper-2); }
.section-title { font-size: clamp(26px, 6.4vw, 40px); text-align: center; margin-bottom: 14px; }
.section-lead { color: var(--ink-2); text-align: center; max-width: 36em; margin: 0 auto 36px; }
.dark .section-title { text-shadow: 0 2px 18px rgba(0, 0, 0, 0.4); }
.dark .section-lead { color: var(--on-dark-muted); }
.grid-3, .grid-2 { display: grid; gap: 16px; margin-top: 28px; }
@media (min-width: 720px) { .grid-2 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px) { .grid-3 { grid-template-columns: repeat(3, 1fr); } }

/* ---- カード（白。やわらかい影） ---- */
.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 22px;
  box-shadow: 0 6px 24px rgba(20, 20, 19, 0.06);
}
.card h3 { font-size: 19px; margin-bottom: 8px; }
.card p { color: var(--ink-2); }
.card-num, .feature-num, .step-num { color: var(--blue-deep); font-weight: 700; letter-spacing: 0.12em; font-size: 13px; margin-bottom: 8px; font-variant-numeric: tabular-nums; }

/* ---- 機能 ---- */
.feature { display: grid; gap: 22px; align-items: center; margin-top: 52px; }
.feature .phone { margin: 0 auto; max-width: 240px; }
.feature-text { padding: 4px 6px; }
.feature-text h3 { font-size: 24px; margin-bottom: 10px; }
.feature-text p { color: var(--ink-2); }
.feature-text strong { color: var(--ink); }
.feature-cards { margin-top: 56px; }
@media (min-width: 900px) {
  .feature { grid-template-columns: 300px 1fr; gap: 64px; margin-top: 80px; }
  .feature.reverse { grid-template-columns: 1fr 300px; }
  .feature.reverse .phone { order: 2; }
  .feature .phone { max-width: 300px; }
  .feature-text { padding: 0 12px; }
  .feature-text h3 { font-size: 28px; }
}

/* ---- 使い始め方 ---- */
.steps { list-style: none; padding: 0; margin: 28px 0 0; display: grid; gap: 16px; }
@media (min-width: 900px) { .steps { grid-template-columns: repeat(3, 1fr); } }

/* ---- データの扱い ---- */
.fine { color: var(--ink-2); font-size: 14px; margin-top: 22px; text-align: center; }

/* ---- よくある質問 ---- */
.faq { display: grid; gap: 12px; margin-top: 28px; }
.faq details { padding: 0; }
.faq summary { cursor: pointer; list-style: none; padding: 18px 48px 18px 20px; font-weight: 700; position: relative; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 20px; top: 50%; transform: translateY(-50%); color: var(--blue-deep); font-size: 22px; font-weight: 400; }
.faq details[open] summary::after { content: "−"; }
.faq details p { padding: 0 20px 20px; color: var(--ink-2); }

/* ---- 最後の案内（紺） ---- */
.dark { position: relative; overflow: hidden; color: var(--on-dark); background: radial-gradient(120% 80% at 50% 0%, #0f2250 0%, var(--navy) 50%, var(--navy-deep) 100%); }
.final .wrap { position: relative; }
.final-icon { margin: 0 auto 18px; border-radius: 22px; box-shadow: 0 16px 40px rgba(0, 0, 0, 0.45); }
.store { margin-top: 24px; display: flex; flex-direction: column; align-items: center; gap: 10px; }
.store-badge img { width: 163px; height: 60px; }
.store-soon { display: inline-block; color: var(--on-dark); font-size: 14px; padding: 10px 18px; border-radius: 999px; border: 1px solid rgba(255, 255, 255, 0.35); background: rgba(255, 255, 255, 0.08); }
.store-soon[hidden] { display: none; }
.dark .note { margin-top: 18px; }

/* ---- 画面の下 ---- */
.site-footer { background: var(--navy-deep); padding: 36px 0 calc(36px + env(safe-area-inset-bottom)); text-align: center; font-size: 13px; color: var(--on-dark-muted); }
.footer-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px 22px; margin-bottom: 14px; }
.footer-links a { color: var(--on-dark-muted); }
.copyright { margin-top: 8px; }

/* ---- 控えめな表示のアニメーション（画面に入ったときに少しだけ浮かぶ） ---- */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }