:root {
  --brand: #3D5C9B;
  --brand-dark: #2B4577;
  --gold: #E3A73F;
  --bg: #FAF8F4;
  --text: #1B2433;
  --muted: #5B6576;
  --surface: #ffffff;
  --line: rgba(27, 36, 51, 0.08);
  --ring: rgba(61, 92, 155, 0.15);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0F1524;
    --text: #F3EFE6;
    --muted: #9AA3B2;
    --surface: #1E2740;
    --line: rgba(255, 255, 255, 0.08);
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: ui-sans-serif, system-ui, -apple-system, "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  color: var(--text);
  background: linear-gradient(180deg, #FFFFFF, #F6F1EA);
}
@media (prefers-color-scheme: dark) {
  body {
    background:
      radial-gradient(1200px 600px at 20% -10%, rgba(61, 92, 155, 0.22), transparent),
      radial-gradient(900px 500px at 120% -20%, rgba(227, 167, 63, 0.15), transparent),
      #0F1524;
  }
}

header.nav {
  position: sticky; top: 0; z-index: 20;
  backdrop-filter: saturate(180%) blur(10px);
  background: rgba(255, 255, 255, 0.75);
  border-bottom: 1px solid var(--line);
}
@media (prefers-color-scheme: dark) {
  header.nav { background: rgba(15, 21, 36, 0.72); }
}
.container { max-width: 1120px; margin: 0 auto; padding: 0 20px; }
.row { display: flex; gap: 16px; align-items: center; justify-content: space-between; min-height: 64px; }
.logo { display: flex; gap: 10px; align-items: center; }
.logo .logo-mark {
  width: 28px; height: 28px; border-radius: 8px;
  background: linear-gradient(135deg, var(--brand), var(--gold));
  display: inline-flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 900; font-size: 15px;
  box-shadow: 0 4px 10px -4px var(--ring);
}
.logo span:last-child { font-weight: 700; letter-spacing: .2px; }
.nav-actions a { color: var(--text); text-decoration: none; margin-left: 14px; opacity: 0.8; font-size: 14px; }
.nav-actions a:hover { opacity: 1; }

.hero {
  position: relative; overflow: hidden;
  padding: 96px 0 72px;
}
.hero .grid {
  display: grid; grid-template-columns: 1.2fr 1fr; gap: 48px; align-items: center;
}
.badge {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12px; padding: 6px 12px; border-radius: 999px;
  background: rgba(61, 92, 155, 0.08);
  color: var(--brand);
  border: 1px solid rgba(61, 92, 155, 0.16);
  letter-spacing: 0.04em;
}
@media (prefers-color-scheme: dark) { .badge { color: #8AA7DC; background: rgba(138, 167, 220, 0.08); border-color: rgba(138, 167, 220, 0.18); } }
.title {
  font-size: clamp(32px, 6vw, 56px); line-height: 1.08; margin: 16px 0 16px;
  letter-spacing: -0.02em; font-weight: 800;
}
.title .accent { color: var(--brand); }
.lead { font-size: clamp(15px, 2.4vw, 18px); color: var(--muted); margin-bottom: 28px; line-height: 1.8; }
.cta { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.btn {
  appearance: none; border: 0; cursor: pointer;
  border-radius: 12px; padding: 13px 22px; font-weight: 600;
  text-decoration: none; display: inline-block; font-size: 15px;
  transition: transform .15s ease, box-shadow .15s ease;
}
.btn.primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-dark));
  color: #fff;
  box-shadow: 0 12px 24px -12px var(--ring);
}
.btn.primary:hover { transform: translateY(-1px); box-shadow: 0 16px 28px -12px rgba(61, 92, 155, 0.4); }
.btn.disabled { opacity: 0.55; cursor: default; }
.btn.disabled:hover { transform: none; box-shadow: 0 12px 24px -12px var(--ring); }
.btn.secondary { background: rgba(2, 6, 23, 0.04); color: var(--text); border: 1px solid var(--line); }
@media (prefers-color-scheme: dark) {
  .btn.secondary { background: rgba(255, 255, 255, 0.05); }
}
.note { font-size: 12px; color: var(--muted); margin-top: 12px; }

.hero-visual {
  position: relative;
  aspect-ratio: 3/4;
  border-radius: 28px;
  background: linear-gradient(160deg, #FFFFFF 0%, #F6F1EA 60%, #EEE6D8 100%);
  border: 1px solid var(--line);
  overflow: hidden;
  display: flex; align-items: center; justify-content: center;
}
@media (prefers-color-scheme: dark) {
  .hero-visual { background: linear-gradient(160deg, #1E2740 0%, #141B2B 100%); }
}
.hero-visual:before {
  content: ""; position: absolute; inset: -20%;
  background:
    radial-gradient(500px 260px at 15% 15%, rgba(61, 92, 155, 0.22), transparent 60%),
    radial-gradient(420px 220px at 85% 80%, rgba(227, 167, 63, 0.22), transparent 60%);
  filter: blur(4px);
}
.hero-amount {
  position: relative; z-index: 2; text-align: center;
  padding: 0 24px;
}
.hero-amount .label {
  font-size: 13px; font-weight: 600; color: var(--muted);
  letter-spacing: 0.24em; text-transform: uppercase;
  margin-bottom: 12px;
}
.hero-amount .amount {
  font-size: clamp(48px, 9vw, 104px);
  font-weight: 900; letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--brand), var(--gold));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1;
}
.hero-amount .sub {
  font-size: 13px; color: var(--muted); margin-top: 10px;
}

.section { padding: 72px 0; }
.section h2 { font-size: clamp(22px, 4vw, 32px); margin: 0 0 10px; letter-spacing: -0.01em; }
.section p.desc { color: var(--muted); margin: 0 0 32px; font-size: 15px; }
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
@media (max-width: 900px) {
  .hero .grid { grid-template-columns: 1fr; }
  .features { grid-template-columns: 1fr; }
}
.card {
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 22px;
  background: var(--surface);
  transition: transform .2s ease, border-color .2s ease;
}
.card:hover { transform: translateY(-2px); border-color: rgba(61, 92, 155, 0.24); }
.card h3 { margin: 10px 0 8px; font-size: 17px; font-weight: 700; }
.card p { margin: 0; color: var(--muted); line-height: 1.75; font-size: 14px; }
.card .icon {
  width: 36px; height: 36px; border-radius: 10px;
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 18px;
  background: rgba(61, 92, 155, 0.08); color: var(--brand);
}
.card.gold .icon { background: rgba(227, 167, 63, 0.14); color: var(--gold); }

.principles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
@media (max-width: 900px) { .principles { grid-template-columns: 1fr; } }
.principle {
  padding: 24px; border-radius: 20px;
  background: linear-gradient(160deg, rgba(61, 92, 155, 0.04), rgba(227, 167, 63, 0.04));
  border: 1px solid var(--line);
}
.principle h3 { margin: 0 0 10px; font-size: 18px; font-weight: 700; color: var(--brand); }
@media (prefers-color-scheme: dark) { .principle h3 { color: #8AA7DC; } }
.principle p { margin: 0; color: var(--muted); line-height: 1.8; font-size: 14px; }

.cta-bar { display: flex; gap: 14px; margin-top: 32px; align-items: center; flex-wrap: wrap; }
.store-badges { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.badge-pill {
  font-size: 12px; padding: 7px 12px; border-radius: 999px;
  border: 1px dashed rgba(27, 36, 51, 0.18); color: var(--muted);
}
@media (prefers-color-scheme: dark) { .badge-pill { border-color: rgba(255, 255, 255, 0.18); } }

footer { padding: 40px 0 48px; border-top: 1px solid var(--line); color: var(--muted); margin-top: 32px; }
footer .row { align-items: flex-start; }
footer .links { display: flex; gap: 18px; flex-wrap: wrap; font-size: 14px; }
footer a { color: var(--muted); text-decoration: none; }
footer a:hover { color: var(--text); }
footer .logo span:last-child { color: var(--text); }
footer .meta { font-size: 12px; margin-top: 6px; }

.content { max-width: 760px; margin: 0 auto; padding: 2.5rem 1.25rem 4rem; }
.content h1 { font-size: 2rem; margin: 0 0 0.5rem; letter-spacing: -0.01em; }
.content .update-date { color: var(--muted); margin-bottom: 2rem; font-size: 13px; }
.content h2 { font-size: 1.25rem; margin-top: 2.25rem; margin-bottom: 0.75rem; color: var(--brand); }
@media (prefers-color-scheme: dark) { .content h2 { color: #8AA7DC; } }
.content h3 { font-size: 1.05rem; margin-top: 1.4rem; margin-bottom: 0.5rem; }
.content p, .content ul { line-height: 1.85; margin-bottom: 1rem; font-size: 15px; }
.content ul { padding-left: 1.5rem; }
.content li { margin-bottom: 0.35rem; }
.back-link { display: inline-block; margin-bottom: 2rem; color: var(--brand); text-decoration: none; font-size: 14px; }
@media (prefers-color-scheme: dark) { .back-link { color: #8AA7DC; } }
.back-link:hover { text-decoration: underline; }

.error-container { max-width: 560px; margin: 0 auto; padding: 5rem 1.25rem; text-align: center; }
.error-code { font-size: 5rem; font-weight: 900; color: var(--brand); margin: 0; line-height: 1; letter-spacing: -0.04em; }
.error-title { font-size: 1.4rem; margin: 1rem 0 0.5rem; }
.error-message { color: var(--muted); margin-bottom: 2rem; line-height: 1.7; }
.error-emoji { font-size: 3rem; margin-bottom: 0.75rem; }

[data-animate] { opacity: 0; transform: translateY(8px); animation: fadeIn .7s ease forwards; }
@keyframes fadeIn { to { opacity: 1; transform: none; } }
@media (prefers-reduced-motion: reduce) { [data-animate] { opacity: 1; transform: none; animation: none; } }