:root {
  --bg: #ffffff;
  --bg-alt: #f5f7fa;
  --ink: #0f1722;
  --ink-soft: #46566b;
  --accent: #1f6feb;
  --accent-2: #ff7a3d;
  --line: #e3e8ef;
  --radius: 14px;
  --maxw: 1080px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.container.narrow { max-width: 760px; }

.hero {
  background: radial-gradient(1200px 600px at 20% 0%, rgba(31,111,235,0.18), transparent 60%),
              radial-gradient(900px 500px at 90% 10%, rgba(255,122,61,0.16), transparent 60%),
              linear-gradient(180deg, #0f1722 0%, #142033 100%);
  color: #fff;
  padding: 96px 0 88px;
  text-align: center;
}
.hero-icon {
  border-radius: 24px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.35);
  margin-bottom: 28px;
}
.hero h1 {
  font-size: clamp(40px, 6vw, 64px);
  margin: 0 0 12px;
  letter-spacing: -0.02em;
}
.tagline {
  font-size: clamp(17px, 2vw, 20px);
  color: #c7d2e1;
  max-width: 620px;
  margin: 0 auto 36px;
}

.cta-row { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.store-btn {
  display: inline-flex;
  flex-direction: column;
  align-items: flex-start;
  text-decoration: none;
  color: #fff;
  background: #000;
  border: 1px solid #2a3242;
  padding: 10px 22px;
  border-radius: 12px;
  min-width: 180px;
  transition: transform 120ms ease, border-color 120ms ease;
}
.store-btn:hover { transform: translateY(-1px); border-color: var(--accent); }
.store-sub { font-size: 11px; opacity: 0.8; text-transform: uppercase; letter-spacing: 0.06em; }
.store-name { font-size: 20px; font-weight: 600; }

.section { padding: 88px 0; }
.section-alt { background: var(--bg-alt); }
.section h2 {
  font-size: clamp(26px, 3vw, 34px);
  margin: 0 0 40px;
  letter-spacing: -0.01em;
}

.steps {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  counter-reset: step;
}
.steps li {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px;
  position: relative;
  counter-increment: step;
}
.steps li::before {
  content: counter(step);
  position: absolute;
  top: 16px; right: 20px;
  font-size: 14px;
  color: var(--ink-soft);
  font-variant-numeric: tabular-nums;
}
.step-icon {
  width: 48px; height: 48px;
  border-radius: 12px;
  display: grid; place-items: center;
  background: rgba(31,111,235,0.10);
  color: var(--accent);
  margin-bottom: 16px;
}
.steps h3 { margin: 0 0 6px; font-size: 18px; }
.steps p { margin: 0; color: var(--ink-soft); }

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}
.card h3 { margin: 0 0 6px; font-size: 17px; }
.card p { margin: 0; color: var(--ink-soft); font-size: 15px; }

details {
  border-top: 1px solid var(--line);
  padding: 18px 0;
}
details:last-of-type { border-bottom: 1px solid var(--line); }
summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
  position: relative;
  padding-right: 28px;
}
summary::-webkit-details-marker { display: none; }
summary::after {
  content: "+";
  position: absolute;
  right: 0; top: 0;
  font-size: 22px;
  color: var(--ink-soft);
  line-height: 1;
}
details[open] summary::after { content: "−"; }
details p { color: var(--ink-soft); margin: 10px 0 0; }

.footer {
  border-top: 1px solid var(--line);
  padding: 28px 0;
  color: var(--ink-soft);
  font-size: 14px;
}
.footer-inner { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.footer a { color: var(--ink-soft); text-decoration: none; }
.footer a:hover { color: var(--ink); }
.sep { margin: 0 8px; opacity: 0.5; }

@media (max-width: 720px) {
  .steps, .grid { grid-template-columns: 1fr; }
  .hero { padding: 72px 0 64px; }
  .section { padding: 64px 0; }
}