:root {
  --bg: #ffffff;
  --text: #111111;
  --muted: #525252;
  --line: #d8d8d8;
  --soft: #f5f5f5;
  --card: #ffffff;
  --shadow: 0 18px 48px rgba(0,0,0,0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a {
  color: inherit;
}

.site-header {
  width: min(1080px, calc(100% - 32px));
  margin: 0 auto;
  padding: 24px 0;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  border-bottom: 1px solid var(--line);
}

.logo {
  font-weight: 800;
  letter-spacing: -0.04em;
  font-size: 1.25rem;
}

.nav {
  display: flex;
  gap: 18px;
  color: var(--muted);
  font-size: 0.95rem;
}

.nav a {
  text-decoration: none;
}

.nav a:hover {
  color: var(--text);
}

.hero {
  width: min(1080px, calc(100% - 32px));
  margin: 0 auto;
  padding: 78px 0 52px;
  display: grid;
  grid-template-columns: 1fr 0.85fr;
  gap: 42px;
  align-items: center;
}

.badge {
  display: inline-flex;
  width: fit-content;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 8px 13px;
  color: var(--muted);
  background: var(--soft);
  font-size: 0.92rem;
}

h1 {
  margin: 20px 0 14px;
  font-size: clamp(3rem, 8vw, 6rem);
  line-height: 0.94;
  letter-spacing: -0.08em;
}

.lede {
  max-width: 680px;
  color: var(--muted);
  font-size: clamp(1.15rem, 2vw, 1.5rem);
  margin: 0 0 24px;
}

.promise {
  display: grid;
  gap: 10px;
  margin: 28px 0;
  padding: 0;
  list-style: none;
}

.promise li {
  border: 1px solid var(--line);
  background: var(--soft);
  border-radius: 14px;
  padding: 12px 14px;
  font-weight: 700;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding: 13px 19px;
  min-height: 48px;
  text-decoration: none;
  font-weight: 800;
  border: 1px solid var(--text);
  background: var(--text);
  color: var(--bg);
}

.button.secondary {
  background: var(--bg);
  color: var(--text);
}

.mock-app {
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--card);
  box-shadow: var(--shadow);
  padding: 24px;
}

.mock-top {
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  border-bottom: 1px solid var(--line);
  padding-bottom: 14px;
  margin-bottom: 18px;
}

.amount {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  letter-spacing: -0.06em;
  font-weight: 900;
  margin: 0 0 8px;
}

.mock-row {
  display: flex;
  justify-content: space-between;
  border-top: 1px solid var(--line);
  padding: 14px 0;
}

.mock-row span:last-child {
  font-weight: 800;
}

.section {
  width: min(1080px, calc(100% - 32px));
  margin: 0 auto;
  padding: 54px 0;
}

.section h2 {
  margin: 0 0 12px;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.05;
  letter-spacing: -0.06em;
}

.section-intro {
  max-width: 760px;
  color: var(--muted);
  font-size: 1.1rem;
  margin: 0 0 26px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.card {
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--card);
  padding: 22px;
}

.card h3 {
  margin: 0 0 8px;
  font-size: 1.12rem;
}

.card p {
  margin: 0;
  color: var(--muted);
}

.cta {
  margin: 40px 0 18px;
  border: 1px solid var(--line);
  background: var(--soft);
  border-radius: 28px;
  padding: clamp(24px, 5vw, 42px);
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 20px;
  align-items: center;
}

.cta p {
  margin: 0;
  color: var(--muted);
}

.site-footer {
  width: min(1080px, calc(100% - 32px));
  margin: 0 auto;
  padding: 36px 0 46px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-links {
  display: flex;
  gap: 16px;
}

.footer-links a {
  text-decoration: none;
}

.simple-page {
  width: min(800px, calc(100% - 32px));
  margin: 0 auto;
  padding: 60px 0;
}

.simple-page h1 {
  font-size: clamp(2.4rem, 7vw, 4.5rem);
}

.simple-page p,
.simple-page li {
  color: var(--muted);
}

.notice {
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--soft);
  padding: 18px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #050505;
    --text: #f7f7f7;
    --muted: #bdbdbd;
    --line: #2e2e2e;
    --soft: #111111;
    --card: #080808;
    --shadow: 0 18px 48px rgba(0,0,0,0.40);
  }
}

@media (max-width: 820px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero {
    grid-template-columns: 1fr;
    padding-top: 44px;
  }

  .grid {
    grid-template-columns: 1fr;
  }

  .cta {
    grid-template-columns: 1fr;
  }

  .nav {
    flex-wrap: wrap;
  }
}