:root {
  --bg: #fafaf8;
  --surface: #ffffff;
  --text: #1a1a18;
  --muted: #6b6b66;
  --line: #e8e6e1;
  --accent: #2f3d36;
  --accent-hover: #24302a;
  --max: 640px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: Inter, "Noto Sans SC", -apple-system, BlinkMacSystemFont,
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 16px;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

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

ul, ol {
  list-style: none;
}

.wrap {
  width: min(100% - 2.5rem, var(--max));
  margin-inline: auto;
}

/* Nav */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(250, 250, 248, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
}

.nav-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.1rem 0;
}

.brand {
  font-size: 0.92rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--text);
}

.nav-link {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--muted);
  padding: 0.35rem 0;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.nav-link:hover {
  color: var(--text);
  border-bottom-color: var(--text);
}

/* Hero */
.hero {
  padding: 4.5rem 0 3.5rem;
  text-align: center;
}

.eyebrow {
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: none;
  color: var(--muted);
  margin-bottom: 1.25rem;
}

.hero h1 {
  font-size: clamp(1.85rem, 6vw, 2.35rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin-bottom: 1rem;
}

.price {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 0.2rem;
  margin-bottom: 1.35rem;
}

.price .num {
  font-size: clamp(2.6rem, 8vw, 3.25rem);
  font-weight: 600;
  letter-spacing: -0.04em;
  color: var(--text);
  line-height: 1;
}

.price .per {
  font-size: 0.95rem;
  color: var(--muted);
  font-weight: 400;
}

.lead {
  color: var(--muted);
  font-size: 0.98rem;
  max-width: 28rem;
  margin: 0 auto 2rem;
  line-height: 1.7;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--accent);
  color: #fafaf8;
  font-size: 0.92rem;
  font-weight: 500;
  padding: 0.85rem 1.6rem;
  border-radius: 2px;
  letter-spacing: 0.02em;
  transition: background 0.2s ease;
}

.btn:hover {
  background: var(--accent-hover);
  color: #fafaf8;
}

/* Features */
.features {
  padding: 0 0 3.5rem;
}

.cards {
  display: grid;
  gap: 0.85rem;
}

@media (min-width: 640px) {
  .cards {
    grid-template-columns: repeat(3, 1fr);
    gap: 0.75rem;
  }
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: 1.35rem 1.2rem;
}

.card h2 {
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  margin-bottom: 0.55rem;
}

.card p {
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.65;
}

/* How */
.how {
  padding: 0 0 3.5rem;
}

.how-inner {
  border-top: 1px solid var(--line);
  padding-top: 2.75rem;
}

.how h2 {
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin-bottom: 1.25rem;
  text-align: center;
}

.how ol {
  display: grid;
  gap: 0.85rem;
  counter-reset: step;
  max-width: 22rem;
  margin: 0 auto;
}

.how li {
  counter-increment: step;
  display: grid;
  grid-template-columns: 1.5rem 1fr;
  gap: 0.75rem;
  align-items: start;
  font-size: 0.94rem;
  color: var(--text);
  line-height: 1.55;
}

.how li::before {
  content: counter(step);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--muted);
  line-height: 1.7;
}

/* Contact */
.contact {
  padding: 0 0 4rem;
}

.contact-box {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 2px;
  padding: 2.25rem 1.5rem 2rem;
  text-align: center;
  max-width: 360px;
  margin: 0 auto;
}

.contact-box h2 {
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 0.35rem;
}

.contact-box .sub {
  font-size: 0.88rem;
  color: var(--muted);
  margin-bottom: 1.5rem;
}

.qr {
  display: inline-block;
  margin: 0 auto 1.15rem;
  padding: 0.5rem;
  border: 1px solid var(--line);
  background: #fff;
  border-radius: 2px;
}

.qr img {
  width: 220px;
  max-width: min(220px, 70vw);
  height: auto;
  image-rendering: -webkit-optimize-contrast;
}

.who {
  font-size: 0.9rem;
  margin-bottom: 0.35rem;
}

.who strong {
  font-weight: 600;
}

.hint {
  font-size: 0.82rem;
  color: var(--muted);
}

/* Footer */
.footer {
  border-top: 1px solid var(--line);
  padding: 2.25rem 0 2.75rem;
  text-align: center;
}

.foot-price {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 0.85rem;
}

.disclaimer {
  font-size: 0.78rem;
  color: var(--muted);
  line-height: 1.75;
  max-width: 34rem;
  margin: 0 auto 1.1rem;
}

.copy {
  font-size: 0.75rem;
  color: var(--muted);
}

@media (max-width: 380px) {
  .wrap {
    width: min(100% - 1.75rem, var(--max));
  }

  .hero {
    padding-top: 3.25rem;
  }
}