/* ── Reset & Base ── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --c-bg: #f2f4f9;
  --c-surface: #ffffff;
  --c-soft: #e8ecf5;
  --c-text: #181d2e;
  --c-muted: #64708f;
  --c-accent: #3851d1;
  --c-accent-dark: #2a3fb0;
  --c-accent-soft: #eaecfd;
  --c-border: #d5d9eb;
  --font-display: "Bricolage Grotesque", system-ui, sans-serif;
  --font-body: "DM Sans", "Hiragino Sans", "Helvetica Neue", system-ui, sans-serif;
  --font-jp: "Zen Kaku Gothic New", "Hiragino Sans", system-ui, sans-serif;
  --max-w: 1040px;
  --section-py: clamp(72px, 11vh, 128px);
}

@media (prefers-color-scheme: dark) {
  :root {
    --c-bg: #0d1117;
    --c-surface: #141b27;
    --c-soft: #1a2333;
    --c-text: #e5eaf5;
    --c-muted: #8896b5;
    --c-accent-soft: #0e1535;
    --c-border: #1e2d45;
  }
}

html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

:lang(ja) h1,
:lang(ja) h2,
:lang(ja) .lede,
:lang(ja) .step strong { font-family: var(--font-jp); }

a { color: var(--c-accent); text-decoration: none; }
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }

/* ── Fade-up ── */
.fade-up {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}
.fade-up.visible { opacity: 1; transform: none; }

/* ── Language switch ── */
.lang-switch {
  position: fixed;
  top: 20px; right: 20px;
  z-index: 100;
  display: flex;
  gap: 2px;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--c-border);
  border-radius: 10px;
  padding: 4px;
  box-shadow: 0 2px 16px -6px rgba(24, 29, 46, 0.12);
}
@media (prefers-color-scheme: dark) {
  .lang-switch { background: rgba(20, 27, 39, 0.9); }
}
.lang-switch a {
  padding: 5px 11px;
  border-radius: 6px;
  font-size: 0.77rem;
  font-weight: 600;
  color: var(--c-muted);
  letter-spacing: 0.04em;
  transition: background 0.2s, color 0.2s;
}
.lang-switch a.active { background: var(--c-text); color: var(--c-bg); }
.lang-switch a:hover:not(.active) { color: var(--c-text); }

/* ── Hero ── */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: clamp(96px, 14vh, 160px) 24px clamp(72px, 10vh, 112px);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 720px 520px at 18% -4%, rgba(56, 81, 209, 0.08), transparent 62%),
    radial-gradient(ellipse 640px 480px at 85% 96%, rgba(56, 81, 209, 0.06), transparent 62%);
  pointer-events: none;
}
.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 680px;
  width: 100%;
}

.hero-wordmark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 28px;
}
.hero-icon {
  width: 56px; height: 56px;
  border-radius: 14px;
  display: block;
  box-shadow: 0 6px 24px -8px rgba(56, 81, 209, 0.28);
}
.wordmark-text {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--c-text);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 13px;
  border-radius: 100px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  background: var(--c-accent-soft);
  color: var(--c-accent);
  margin-bottom: 22px;
}
.hero-badge::before {
  content: "";
  width: 5px; height: 5px;
  border-radius: 50%;
  background: currentColor;
  flex-shrink: 0;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(3.2rem, 9vw, 6rem);
  font-weight: 800;
  letter-spacing: -0.045em;
  line-height: 1.0;
  margin-bottom: 30px;
  color: var(--c-text);
}
.hero h1 .accent { color: var(--c-accent); }

/* ── Waveform ── */
.waveform {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  height: 52px;
  margin: 0 auto 32px;
}
.waveform-bar {
  width: 4px;
  border-radius: 2px;
  background: var(--c-accent);
  opacity: 0.7;
  animation: wave-pulse 1.55s ease-in-out infinite;
}
@keyframes wave-pulse {
  0%, 100% { transform: scaleY(0.2); opacity: 0.3; }
  50% { transform: scaleY(1); opacity: 0.85; }
}
.waveform-bar:nth-child(1)  { height: 14px; animation-delay: 0.00s; }
.waveform-bar:nth-child(2)  { height: 26px; animation-delay: 0.07s; }
.waveform-bar:nth-child(3)  { height: 40px; animation-delay: 0.14s; }
.waveform-bar:nth-child(4)  { height: 48px; animation-delay: 0.21s; }
.waveform-bar:nth-child(5)  { height: 36px; animation-delay: 0.28s; }
.waveform-bar:nth-child(6)  { height: 20px; animation-delay: 0.35s; }
.waveform-bar:nth-child(7)  { height: 44px; animation-delay: 0.42s; }
.waveform-bar:nth-child(8)  { height: 32px; animation-delay: 0.49s; }
.waveform-bar:nth-child(9)  { height: 50px; animation-delay: 0.56s; }
.waveform-bar:nth-child(10) { height: 28px; animation-delay: 0.63s; }
.waveform-bar:nth-child(11) { height: 42px; animation-delay: 0.70s; }
.waveform-bar:nth-child(12) { height: 18px; animation-delay: 0.77s; }
.waveform-bar:nth-child(13) { height: 36px; animation-delay: 0.84s; }
.waveform-bar:nth-child(14) { height: 24px; animation-delay: 0.91s; }
.waveform-bar:nth-child(15) { height: 46px; animation-delay: 0.98s; }

@media (prefers-reduced-motion: reduce) {
  .waveform-bar { animation: none; transform: none; opacity: 0.45; }
}

.lede {
  font-size: clamp(1rem, 1.55vw, 1.15rem);
  color: var(--c-muted);
  max-width: 540px;
  margin: 0 auto 40px;
  font-weight: 400;
  line-height: 1.72;
}

.cta-group { display: flex; flex-direction: column; align-items: center; gap: 12px; }

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 30px;
  background: var(--c-text);
  color: var(--c-bg);
  border-radius: 12px;
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: -0.01em;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 4px 24px -8px rgba(24, 29, 46, 0.28);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px -8px rgba(24, 29, 46, 0.36);
  color: var(--c-bg);
}
.btn-primary svg { width: 18px; height: 18px; flex-shrink: 0; }

.cta-note {
  font-size: 0.82rem;
  color: var(--c-muted);
  font-weight: 500;
}

/* ── Features ── */
.features {
  padding: var(--section-py) 0;
  background: var(--c-surface);
  border-top: 1px solid var(--c-border);
  border-bottom: 1px solid var(--c-border);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2px;
  background: var(--c-border);
  border: 2px solid var(--c-border);
  border-radius: 22px;
  overflow: hidden;
}

.feature-card {
  background: var(--c-surface);
  padding: 38px 34px;
}

.feature-icon {
  width: 42px; height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--c-accent-soft);
  border-radius: 11px;
  margin-bottom: 22px;
  flex-shrink: 0;
}
.feature-icon svg {
  width: 20px; height: 20px;
  stroke: var(--c-accent);
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.feature-card h3 {
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 10px;
  color: var(--c-text);
}
.feature-card p {
  font-size: 0.92rem;
  color: var(--c-muted);
  line-height: 1.68;
}

@media (max-width: 720px) {
  .features-grid { grid-template-columns: 1fr; }
}

/* ── How it works ── */
.how { padding: var(--section-py) 0; }

.how h2 {
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 4vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -0.035em;
  text-align: center;
  margin-bottom: 56px;
  color: var(--c-text);
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  list-style: none;
  counter-reset: steps;
}

.step {
  counter-increment: steps;
  padding: 34px 30px;
  background: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 20px;
  position: relative;
}

.step::before {
  content: "0" counter(steps);
  display: block;
  font-family: var(--font-display);
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.06em;
  line-height: 1;
  color: var(--c-accent);
  opacity: 0.15;
  margin-bottom: 14px;
}

.step strong {
  display: block;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--c-text);
  margin-bottom: 9px;
}
.step p {
  font-size: 0.9rem;
  color: var(--c-muted);
  line-height: 1.62;
}

@media (max-width: 720px) {
  .steps { grid-template-columns: 1fr; gap: 14px; }
  .how h2 { margin-bottom: 36px; }
}

/* ── Footer ── */
footer {
  padding: 52px 0 44px;
  border-top: 1px solid var(--c-border);
  text-align: center;
  background: var(--c-soft);
  font-size: 0.85rem;
  color: var(--c-muted);
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--c-text);
  margin-bottom: 14px;
}
.footer-brand img {
  width: 26px; height: 26px;
  border-radius: 7px;
  box-shadow: 0 2px 8px -3px rgba(56, 81, 209, 0.28);
  display: block;
}
.footer-links {
  display: flex;
  justify-content: center;
  gap: 26px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
footer a { color: var(--c-muted); text-decoration: underline; text-underline-offset: 3px; }
footer a:hover { color: var(--c-accent); }

/* ── Legal pages ── */
.legal {
  max-width: 760px;
  margin: 0 auto;
  padding: 96px 28px 80px;
}
.legal .back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--c-muted);
  margin-bottom: 32px;
  text-decoration: none;
  transition: color 0.2s;
}
.legal .back:hover { color: var(--c-accent); }
.legal h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4.2vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 10px;
}
.legal .updated {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--c-accent);
  background: var(--c-accent-soft);
  padding: 4px 12px;
  border-radius: 100px;
  margin-bottom: 36px;
}
.legal h2 {
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 36px 0 12px;
  color: var(--c-text);
}
.legal p, .legal li {
  font-size: 0.97rem;
  color: var(--c-muted);
  line-height: 1.75;
}
.legal ul { padding-left: 20px; margin: 8px 0 4px; }
.legal li { margin: 4px 0; }
.legal strong { color: var(--c-text); font-weight: 600; }
.legal a { color: var(--c-accent); text-decoration: underline; text-underline-offset: 3px; }