:root {
  --ink: #1d1d1f;
  --paper: #ffffff;
  --ash: #f5f5f7;
  --mute: #6e6e73;
  --line: rgba(0, 0, 0, 0.08);
  --black: #000000;
  --silver: #a1a1a6;
  --max: 1160px;
  --header: 68px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-family: "SF Pro Display", "SF Pro Text", -apple-system, BlinkMacSystemFont, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

body { min-height: 100vh; }

a { color: inherit; }

img { max-width: 100%; height: auto; display: block; }

.container {
  width: min(var(--max), calc(100% - 48px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  height: var(--header);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
}

.nav {
  height: 100%;
  width: min(var(--max), calc(100% - 48px));
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 28px;
}

.brand { display: flex; align-items: center; margin-right: auto; }
.brand img { height: 28px; width: auto; }

.nav-links { display: flex; gap: 22px; }
.nav-links a {
  text-decoration: none;
  font-size: 14px;
  color: var(--mute);
  letter-spacing: -0.01em;
}
.nav-links a.active,
.nav-links a:hover { color: var(--black); }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  padding: 0 16px;
  border-radius: 980px;
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: -0.01em;
  border: 0;
  cursor: pointer;
}
.btn-dark { background: var(--black); color: var(--paper); }
.btn-light { background: var(--paper); color: var(--black); height: 44px; padding: 0 22px; font-size: 17px; }
.btn-line {
  background: transparent;
  color: var(--paper);
  border: 1px solid rgba(255, 255, 255, 0.35);
  height: 44px;
  padding: 0 22px;
}

.hero {
  background: var(--black);
  color: #f5f5f7;
  padding: 88px 0 72px;
}
.hero h1 {
  max-width: 14ch;
  font-size: clamp(48px, 7vw, 80px);
  font-weight: 600;
  letter-spacing: -0.035em;
  line-height: 1.02;
}
.lead {
  max-width: 34em;
  margin-top: 22px;
  font-size: 19px;
  line-height: 1.5;
  color: var(--silver);
  font-weight: 400;
}
.hero .btn { margin-top: 28px; }

.hero-stage {
  margin-top: 56px;
  background: #0b0b0b;
  border-radius: 28px;
  min-height: 420px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 36px;
}
.hero-stage img { max-height: 460px; width: auto; margin: 0 auto; }

.section { padding: 88px 0; background: var(--paper); }
.section h2 {
  font-size: clamp(32px, 4vw, 48px);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.08;
}
.section .sub {
  margin-top: 12px;
  max-width: 36em;
  color: var(--mute);
  font-size: 17px;
  line-height: 1.5;
}

.grid-3, .grid-2 {
  display: grid;
  gap: 40px;
  margin-top: 40px;
}
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }

.card { padding: 0; }
.stage {
  background: var(--ash);
  border-radius: 22px;
  min-height: 280px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.stage img { max-height: 240px; width: auto; margin: 0 auto; }
.card h3 {
  margin-top: 18px;
  font-size: 21px;
  font-weight: 600;
  letter-spacing: -0.02em;
}
.card p {
  margin-top: 6px;
  color: var(--mute);
  font-size: 15px;
  line-height: 1.5;
}
.card a.more {
  display: inline-block;
  margin-top: 10px;
  color: var(--black);
  font-size: 14px;
}

.sheet {
  background: var(--black);
  color: #f5f5f7;
}
.sheet .sub { color: var(--silver); }
.sheet .stage { background: #111; }
.sheet .card p { color: var(--silver); }
.sheet .card a.more { color: #f5f5f7; }

.page-hero { padding: 72px 0 24px; }
.page-hero h1 {
  font-size: clamp(44px, 6vw, 68px);
  font-weight: 600;
  letter-spacing: -0.035em;
  line-height: 1.04;
  max-width: 12em;
}
.page-hero .lead { color: var(--mute); }
.page-hero .btn-dark { margin-top: 28px; height: 44px; padding: 0 22px; font-size: 17px; }

.steps { margin-top: 28px; }
.step-no {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--mute);
}

.search {
  margin-top: 28px;
  display: flex;
  gap: 12px;
  max-width: 640px;
}
.search input {
  flex: 1;
  height: 48px;
  border: 0;
  border-bottom: 1px solid #d2d2d7;
  background: transparent;
  font: inherit;
  font-size: 17px;
  color: var(--ink);
  outline: none;
}
.search input:focus { border-bottom-color: var(--black); }

.faq { margin-top: 28px; }
.faq article {
  padding: 28px 0;
  border-top: 1px solid var(--line);
}
.faq h3 {
  font-size: 24px;
  font-weight: 600;
  letter-spacing: -0.02em;
}
.faq p {
  margin-top: 8px;
  max-width: 46em;
  color: var(--mute);
  font-size: 17px;
  line-height: 1.55;
}

.footer {
  border-top: 1px solid var(--line);
  background: var(--paper);
}
.footer-row {
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 12px;
  color: var(--mute);
}
.footer nav { display: flex; gap: 18px; }
.footer a { color: var(--mute); text-decoration: none; }
.footer a:hover { color: var(--black); }

@media (max-width: 900px) {
  .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .nav { gap: 14px; }
  .nav-links { gap: 12px; }
  .hero { padding: 56px 0 48px; }
  .hero-stage { min-height: 240px; }
  .section { padding: 56px 0; }
  .footer-row { flex-direction: column; align-items: flex-start; padding: 16px 0; }
}