:root {
  --shell: #4A6838;
  --sage: #78906A;
  --lichen: #BCC478;
  --forest: #2F4528;
  --ink: #1a1a1a;
  --paper: #F5F4EC;
  --paper-2: #ffffff;
  --muted: #6b6b5a;
  --radius: 16px;
  --maxw: 1080px;
  --font: -apple-system, BlinkMacSystemFont, "Pretendard", "Hiragino Sans",
    "Noto Sans JP", "Noto Sans KR", "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
/* Hide content until i18n applies, to avoid a flash of the English fallback.
   enhance/i18n set data-i18n-ready; a 1.5s inline fallback + <noscript> guarantee visibility. */
html:not([data-i18n-ready]) body { visibility: hidden; }
h1, h2, h3 { line-height: 1.12; letter-spacing: -0.02em; margin: 0; }
p { margin: 0; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; }

/* Buttons */
.btn {
  display: inline-block;
  background: var(--shell);
  color: #fff;
  font-weight: 800;
  border-radius: 12px;
  padding: 13px 22px;
  box-shadow: 0 6px 18px rgba(74, 104, 56, 0.35);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.btn:hover { transform: translateY(-1px); box-shadow: 0 8px 22px rgba(74, 104, 56, 0.45); }
.btn-sm { padding: 7px 14px; font-size: 13px; border-radius: 9px; box-shadow: none; }
.btn-lg { font-size: 15px; }
.req { font-size: 13px; color: var(--muted); }

/* Nav */
.nav {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px clamp(16px, 5vw, 40px);
  background: rgba(245, 244, 236, 0.85);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}
.brand { display: flex; align-items: center; gap: 9px; font-weight: 800; }
.brand img { border-radius: 8px; }
.nav-links { display: flex; align-items: center; gap: 16px; font-size: 14px; color: #4f4f44; }
.lang-switch { display: inline-flex; border: 1px solid #d6d6c6; border-radius: 8px; overflow: hidden; }
.lang-switch button {
  border: 0; background: transparent; cursor: pointer;
  padding: 4px 9px; font-size: 12px; font-weight: 700; color: #7a7a6a;
  font-family: inherit;
}
.lang-switch button.active { background: var(--shell); color: #fff; }

/* Layout */
.section { max-width: var(--maxw); margin: 0 auto; padding: clamp(48px, 8vw, 96px) clamp(20px, 6vw, 48px); }
.center { text-align: center; }
.label { font-size: 12px; font-weight: 800; letter-spacing: 0.14em; color: var(--shell); }
.lead { font-size: clamp(16px, 2.2vw, 19px); color: var(--muted); margin-top: 14px; max-width: 60ch; }
.center.lead { margin-left: auto; margin-right: auto; }
h2 { font-size: clamp(26px, 4vw, 38px); font-weight: 900; margin-top: 8px; }

/* Hero */
.hero {
  text-align: center;
  /* full-bleed: gradient spans the whole viewport; content stays centered to --maxw via padding */
  padding: clamp(40px, 7vw, 72px) max(clamp(20px, 6vw, 48px), calc((100% - var(--maxw)) / 2)) clamp(48px, 8vw, 80px);
  background: radial-gradient(125% 110% at 50% -10%, #fcfbf4 0%, var(--paper) 55%, #edeee2 100%);
}
.hero-turtle { width: clamp(140px, 22vw, 188px); height: auto; filter: drop-shadow(0 16px 26px rgba(60, 72, 40, 0.2)); }
.hero-title { font-size: clamp(34px, 6vw, 48px); font-weight: 900; margin-top: 18px; }
.hero-title .accent { color: var(--shell); }
.hero-sub { font-size: clamp(15px, 2.4vw, 18px); color: var(--muted); margin: 16px auto 0; max-width: 46ch; }
.hero-actions { display: flex; gap: 14px; align-items: center; justify-content: center; flex-wrap: wrap; margin-top: 26px; }
.hero-privacy { font-size: 12px; color: #9a9a88; margin-top: 16px; }

/* Steps */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; margin-top: 36px; }
.step { background: var(--paper-2); border: 1px solid #ece9dd; border-radius: var(--radius); padding: 26px; }
.step-num {
  display: inline-grid; place-items: center; width: 34px; height: 34px;
  border-radius: 50%; background: var(--lichen); color: var(--forest);
  font-weight: 900; margin-bottom: 12px;
}
.step h3 { font-size: 19px; }
.step p { color: var(--muted); margin-top: 8px; }

/* Gate compare */
.gate { background: var(--paper-2); border-radius: var(--radius); }
.compare { list-style: none; padding: 0; margin: 30px auto 0; max-width: 620px; display: grid; gap: 12px; }
.compare li {
  display: flex; align-items: baseline; justify-content: space-between; gap: 16px;
  padding: 16px 20px; border: 1px solid #ece9dd; border-radius: 12px;
}
.cmp-name { font-weight: 800; }
.cmp-desc { color: var(--muted); text-align: right; }
.cmp-highlight { border-color: var(--shell); background: rgba(188, 196, 120, 0.16); }
.cmp-highlight .cmp-desc { color: var(--forest); }
.precommit { text-align: center; max-width: 56ch; margin: 26px auto 0; color: var(--muted); }

/* Dark sections */
.dark { background: var(--forest); color: #fff; border-radius: 0; max-width: none; }
.dark .lead { color: #cdd3c2; }
.dark.section { padding-left: clamp(20px, 6vw, 48px); padding-right: clamp(20px, 6vw, 48px); }
.dark > * { max-width: var(--maxw); margin-left: auto; margin-right: auto; }
.points { list-style: none; padding: 0; margin: 26px auto 0; display: flex; flex-wrap: wrap; gap: 12px; justify-content: flex-start; }
.points li { background: rgba(255, 255, 255, 0.1); border-radius: 999px; padding: 8px 16px; font-weight: 700; font-size: 14px; }

/* Features */
.feature-grid { list-style: none; padding: 0; margin: 36px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.feature-grid li {
  background: var(--paper-2); border: 1px solid #ece9dd; border-radius: 12px;
  padding: 20px; font-weight: 600; border-left: 4px solid var(--sage);
}

/* FAQ */
.faq-list { max-width: 720px; margin: 30px auto 0; display: grid; gap: 10px; }
.faq-list details { background: var(--paper-2); border: 1px solid #ece9dd; border-radius: 12px; padding: 4px 18px; }
.faq-list summary { cursor: pointer; font-weight: 700; padding: 14px 0; list-style: none; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; float: right; color: var(--shell); font-weight: 900; }
.faq-list details[open] summary::after { content: "–"; }
.faq-list details p { color: var(--muted); padding-bottom: 16px; }

/* CTA band */
.cta-band { text-align: center; background: var(--lichen); border-radius: var(--radius); }
.cta-band h2 { color: var(--forest); }
.cta-band .btn { margin-top: 18px; }
.cta-band .req { color: #5d6b3f; margin-top: 12px; }
.install-note { font-size: 12px; color: var(--muted); margin-top: 10px; }
.cta-band .install-note { color: #5d6b3f; }

/* Footer */
.footer {
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
  background: var(--forest); color: #cdd3c2;
  padding: 28px clamp(20px, 6vw, 48px); font-size: 13px;
}
.footer img { border-radius: 8px; }
.footer-tagline { font-weight: 700; color: #fff; }
.footer-meta { display: flex; align-items: center; gap: 16px; margin-left: auto; flex-wrap: wrap; }
.lang-switch--footer { border-color: rgba(255, 255, 255, 0.25); }
.lang-switch--footer button { color: #cdd3c2; }
.lang-switch--footer button.active { background: var(--lichen); color: var(--forest); }

/* Scroll reveal */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

/* Responsive */
@media (max-width: 760px) {
  .nav-links { gap: 10px; font-size: 13px; }
  .nav-links a[href="#how"], .nav-links a[href="#privacy"], .nav-links a[href="#faq"] { display: none; }
  .steps, .feature-grid { grid-template-columns: 1fr; }
  .compare li { flex-direction: column; gap: 4px; }
  .cmp-desc { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .btn { transition: none; }
}