/* STRETCHLOCK Web — design tokens. See design.md (source of truth).
   Aligned to the extension theme (src/styles/theme.css "sky aqua"). */
:root {
  --brand: #00a8cc;        /* primary */
  --brand-ink: #007e9c;    /* darker: text / icons / hover */
  --brand-2: #0d8fc9;      /* gradient partner (blue) */
  --ink: #002a38;
  --ink-soft: #4a90a8;
  --line: #d4ecf4;
  --bg: #ffffff;
  --bg-soft: #f1fafd;
  --bg-band: #e6f6fb;
  --radius: 16px;
  --shadow-sm: 0 1px 3px rgba(0,42,56,.06), 0 1px 2px rgba(0,42,56,.04);
  --shadow-md: 0 12px 30px rgba(0,42,56,.10);
  --grad: linear-gradient(90deg, var(--brand) 0%, var(--brand-2) 100%);
  --maxw: 1080px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Hiragino Sans', 'Noto Sans JP', sans-serif;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font); color: var(--ink); background: var(--bg); line-height: 1.6; -webkit-font-smoothing: antialiased; }
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
svg { display: block; }

/* ── language switch ── */
.lang-en .ja, .lang-ja .en { display: none; }

.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ── header ── */
header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.86); backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav { display: flex; align-items: center; gap: 20px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 18px; letter-spacing: .04em; }
.brand img { width: 30px; height: 30px; }
.nav-spacer { flex: 1; }
.nav-links { display: flex; gap: 22px; font-size: 14px; font-weight: 600; color: var(--ink-soft); }
.nav-links a:hover { color: var(--ink); }
.lang-toggle {
  display: inline-flex; border: 1px solid var(--line); border-radius: 9999px; overflow: hidden; font-size: 12.5px; font-weight: 700;
}
.lang-toggle button { border: 0; background: transparent; padding: 6px 12px; cursor: pointer; color: var(--ink-soft); font-family: inherit; }
.lang-toggle button.active { background: var(--ink); color: #fff; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-weight: 700; font-size: 15px; padding: 12px 22px; border-radius: 9999px; cursor: pointer; border: 0;
  font-family: inherit;
  transition: transform .12s ease, box-shadow .12s ease, background .12s ease;
}
.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 6px 16px rgba(0,168,204,.28); }
.btn-primary:hover { transform: translateY(-1px); background: var(--brand-ink); box-shadow: 0 10px 22px rgba(0,168,204,.36); }
.btn-ghost { background: #fff; color: var(--ink); border: 1px solid var(--line); }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand-ink); }
.btn-sm { padding: 9px 16px; font-size: 14px; }

/* ── hero ── */
.hero { padding: 72px 0 64px; background:
  radial-gradient(900px 380px at 88% -8%, rgba(0,168,204,.10), transparent 60%),
  radial-gradient(700px 320px at 0% 10%, rgba(13,143,201,.08), transparent 55%);
}
.hero-grid { display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; font-size: 13px; font-weight: 700; color: var(--brand-ink);
  background: #ffffff; border: 1px solid var(--line); padding: 6px 14px; border-radius: 9999px; margin-bottom: 20px; box-shadow: var(--shadow-sm); }
.hero h1 { font-size: 48px; line-height: 1.12; font-weight: 800; letter-spacing: -.01em; }
.lang-ja .hero h1 { font-size: 40px; line-height: 1.22; }
.hero h1 .accent { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p.lead { margin-top: 18px; font-size: 18px; color: var(--ink-soft); max-width: 30em; }
.hero-cta { margin-top: 30px; display: flex; gap: 14px; flex-wrap: wrap; }
.hero-note { margin-top: 16px; font-size: 13px; color: var(--ink-soft); display: flex; align-items: center; gap: 8px; }
.hero-note svg { width: 16px; height: 16px; color: var(--brand-ink); flex: none; }
.hero-shot { position: relative; }
.hero-shot img { border-radius: var(--radius); box-shadow: var(--shadow-md); border: 1px solid var(--line); }

/* ── section frame ── */
section.block { padding: 76px 0; }
.section-head { text-align: center; max-width: 40em; margin: 0 auto 48px; }
.section-head h2 { font-size: 32px; font-weight: 800; letter-spacing: -.01em; }
.lang-ja .section-head h2 { font-size: 28px; }
.section-head p { margin-top: 12px; color: var(--ink-soft); font-size: 17px; }
.kicker { font-size: 13px; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; color: var(--brand-ink); }

/* ── steps ── */
.band { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.step { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); display: flex; flex-direction: column; }
.step .shot { background: var(--bg-band); padding: 18px 18px 0; }
.step .shot img { border-radius: 10px 10px 0 0; border: 1px solid var(--line); border-bottom: 0; }
.step .body { padding: 20px 22px 26px; }
.step .num { display: inline-flex; width: 30px; height: 30px; border-radius: 9999px; background: var(--brand); color: #fff; font-weight: 800; font-size: 14px; align-items: center; justify-content: center; margin-bottom: 12px; }
.step h3 { font-size: 18px; font-weight: 700; }
.step p { margin-top: 8px; color: var(--ink-soft); font-size: 14.5px; }

/* ── features ── */
.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 28px 24px; box-shadow: var(--shadow-sm); }
.feature .ic { width: 44px; height: 44px; border-radius: 12px; background: var(--bg-band); color: var(--brand-ink); display: flex; align-items: center; justify-content: center; margin-bottom: 16px; }
.feature .ic svg { width: 22px; height: 22px; }
.feature h3 { font-size: 17px; font-weight: 700; }
.feature p { margin-top: 8px; color: var(--ink-soft); font-size: 14.5px; }

/* ── FAQ ── */
.faq { max-width: 760px; margin: 0 auto; }
.faq details { border: 1px solid var(--line); border-radius: 12px; padding: 4px 20px; margin-bottom: 12px; background: #fff; box-shadow: var(--shadow-sm); }
.faq summary { list-style: none; cursor: pointer; padding: 16px 0; font-weight: 700; font-size: 16px; display: flex; justify-content: space-between; align-items: center; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-size: 22px; color: var(--brand-ink); font-weight: 400; }
.faq details[open] summary::after { content: "\2013"; }
.faq .ans { padding: 0 0 18px; color: var(--ink-soft); font-size: 15px; }

/* ── final CTA ── */
.final { text-align: center; }
.final h2 { font-size: 34px; font-weight: 800; }
.lang-ja .final h2 { font-size: 28px; }
.final p { margin: 14px auto 28px; color: var(--ink-soft); font-size: 17px; max-width: 36em; }

/* ── footer ── */
footer { border-top: 1px solid var(--line); background: var(--bg-soft); padding: 40px 0; }
.foot { display: flex; justify-content: space-between; align-items: center; gap: 20px; flex-wrap: wrap; }
.foot .brand { font-size: 16px; }
.foot-links { display: flex; gap: 22px; font-size: 14px; font-weight: 600; color: var(--ink-soft); }
.foot-links a:hover { color: var(--ink); }
.copy { font-size: 13px; color: var(--ink-soft); }

/* ── legal pages ── */
.legal { padding: 56px 0 80px; }
.legal .wrap { max-width: 820px; }
.legal h1 { font-size: 34px; font-weight: 800; }
.lang-ja .legal h1 { font-size: 28px; }
.legal .updated { margin-top: 8px; color: var(--ink-soft); font-size: 14px; }
.legal h2 { font-size: 22px; font-weight: 800; margin-top: 40px; }
.legal h3 { font-size: 17px; font-weight: 700; margin-top: 26px; }
.legal p { margin-top: 12px; color: var(--ink-soft); }
.legal ul { margin-top: 12px; padding-left: 22px; color: var(--ink-soft); }
.legal li { margin-top: 6px; }
.legal a.inline { color: var(--brand-ink); font-weight: 600; }
.legal a.inline:hover { text-decoration: underline; }
.legal .note { margin-top: 28px; padding: 16px 18px; background: var(--bg-soft); border: 1px solid var(--line); border-radius: 12px; font-size: 14px; }
.legal code { background: var(--bg-band); padding: 2px 6px; border-radius: 6px; font-size: 13px; }
.back-home { display: inline-block; margin-top: 8px; font-size: 14px; font-weight: 600; color: var(--brand-ink); }

/* ── responsive ── */
@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; gap: 36px; }
  .hero h1 { font-size: 38px; } .lang-ja .hero h1 { font-size: 32px; }
  .steps { grid-template-columns: 1fr; }
  .features { grid-template-columns: 1fr; }
  .nav-links { display: none; }
}
@media (max-width: 480px) {
  .wrap { padding: 0 18px; }
  .hero { padding: 48px 0 44px; }
  .hero h1 { font-size: 30px; }
  .hero-cta { flex-direction: column; align-items: stretch; }
  .foot { flex-direction: column; align-items: flex-start; }
}