/* 墨心 InkSoul — 落地页样式
   设计语言对齐 macOS 应用：水墨灰阶 + STSong 衬线标题 + 极简 hairline */

:root {
  --bg: #FAFAF7;
  --surface: #FFFFFF;
  --surface-alt: #F5F4EF;
  --text: #1A1A1A;
  --text2: #4A4A4A;
  --text3: #8A8A8A;
  --text-ghost: #B8B8B8;
  --border: rgba(0,0,0,0.08);
  --hairline: rgba(0,0,0,0.05);
  --ink-red: #8B2828;
  --serif: "STSong","Songti SC","Noto Serif SC",ui-serif,"Apple LiGothic",serif;
  --sans: -apple-system,BlinkMacSystemFont,"PingFang SC","Helvetica Neue","Segoe UI","Noto Sans SC",sans-serif;
}

* { box-sizing: border-box; }
html,body { margin: 0; padding: 0; }
body {
  font-family: var(--sans);
  font-weight: 300;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--text); text-decoration: none; border-bottom: 1px solid var(--text3); transition: opacity .15s; }
a:hover { opacity: .65; }

/* ── 顶部导航 ── */
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 22px 48px;
  background: var(--surface);
  border-bottom: 1px solid var(--hairline);
  position: sticky; top: 0; z-index: 10;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}
.brand { display: flex; align-items: center; gap: 10px; border: 0; }
.brand-logo { width: 28px; height: 28px; object-fit: contain; }
.brand-zh { font-family: var(--serif); font-size: 22px; font-weight: 400; line-height: 1; }
.brand-en { font-size: 11px; letter-spacing: 2px; color: var(--text3); align-self: flex-end; padding-bottom: 2px; }
.nav nav { display: flex; gap: 26px; }
.nav nav a { font-size: 13px; color: var(--text2); border: 0; }

/* ── Hero ── */
.hero {
  text-align: center;
  padding: 80px 32px 80px;
  max-width: 820px;
  margin: 0 auto;
}
.hero-logo {
  width: 96px;
  height: 96px;
  object-fit: contain;
  margin: 0 auto 28px;
  display: block;
  opacity: .92;
}
.hero-title {
  font-family: var(--serif);
  font-size: 56px;
  font-weight: 300;
  letter-spacing: 2px;
  margin: 0 0 20px;
  line-height: 1.2;
}
.hero-tag {
  font-size: 16px;
  color: var(--text2);
  letter-spacing: 1px;
  margin: 0 0 28px;
}
.hero-sub {
  font-size: 15px;
  color: var(--text3);
  line-height: 1.9;
  margin: 0 0 36px;
}
.hero-cta {
  display: flex;
  gap: 14px;
  justify-content: center;
  margin-bottom: 28px;
}
.hero-meta {
  font-size: 12px;
  color: var(--text-ghost);
  letter-spacing: 1px;
  margin: 0;
}

/* ── 按钮 ── */
.btn {
  display: inline-block;
  padding: 11px 24px;
  font-size: 14px;
  font-weight: 400;
  border: 1px solid var(--border);
  border-radius: 0;
  cursor: pointer;
  transition: all .15s;
  border-bottom-width: 1px;
}
.btn-primary {
  background: var(--text);
  color: #fff;
  border-color: var(--text);
}
.btn-primary:hover { background: #333; border-color: #333; opacity: 1; }
.btn-ghost {
  background: var(--surface);
  color: var(--text2);
}
.btn-ghost:hover { background: var(--surface-alt); opacity: 1; }

/* ── Section ── */
.section {
  max-width: 1080px;
  margin: 0 auto;
  padding: 72px 48px;
}
.section-alt {
  background: var(--surface-alt);
  max-width: none;
  padding: 72px 48px;
}
.section-alt > * { max-width: 1080px; margin-left: auto; margin-right: auto; }
.section h2 {
  font-family: var(--serif);
  font-size: 30px;
  font-weight: 400;
  margin: 0 0 32px;
  letter-spacing: 1px;
}
.section-lead {
  font-size: 14px;
  color: var(--text2);
  margin: -16px 0 32px;
  line-height: 1.8;
}

/* ── Grid ── */
.grid { display: grid; gap: 16px; }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-5 { grid-template-columns: repeat(5, 1fr); }
@media (max-width: 880px) { .grid-4, .grid-5 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 540px) { .grid-4, .grid-5 { grid-template-columns: 1fr; } }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 22px 20px;
}
.card h3 {
  font-family: var(--serif);
  font-size: 17px;
  font-weight: 500;
  margin: 0 0 10px;
}
.card p { font-size: 13px; color: var(--text2); margin: 0; line-height: 1.75; }

.personas .card p { font-size: 13.5px; color: var(--text2); line-height: 1.85; }
.personas .card h3 { color: var(--text); margin-bottom: 12px; }

.distill-callout {
  margin-top: 36px;
  padding: 28px 32px;
  background: var(--surface);
  border: 1px solid var(--border);
}
.distill-callout h3 {
  font-family: var(--serif);
  font-size: 19px;
  font-weight: 500;
  margin: 0 0 12px;
}
.distill-callout p {
  font-size: 14.5px;
  color: var(--text2);
  margin: 0 0 8px;
  line-height: 1.85;
}
.distill-callout p:last-child { margin: 0; }
.distill-callout b { color: var(--ink-red); font-weight: 500; }

/* ── Pledge / lists ── */
.pledge { list-style: none; padding: 0; margin: 0 0 18px; }
.pledge li {
  font-size: 14.5px;
  color: var(--text2);
  padding: 12px 0;
  border-bottom: 1px solid var(--hairline);
  line-height: 1.85;
}
.pledge li:last-child { border-bottom: 0; }
.pledge li b { color: var(--text); font-weight: 500; margin-right: 10px; }

.muted { color: var(--text3); }
.small { font-size: 13px; }

/* ── 价格 ── */
.price-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border: 1px solid var(--border);
  margin-bottom: 36px;
}
.price-grid-2 { grid-template-columns: repeat(2, 1fr); max-width: 720px; margin-left: auto; margin-right: auto; margin-bottom: 36px; }
@media (max-width: 880px) { .price-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 540px) { .price-grid, .price-grid-2 { grid-template-columns: 1fr; } }
.price-card {
  padding: 28px 22px;
  text-align: center;
  border-right: 1px solid var(--border);
  background: var(--surface);
}
.price-card:last-child { border-right: 0; }
@media (max-width: 880px) {
  .price-card:nth-child(2n) { border-right: 0; }
  .price-card:nth-child(-n+2) { border-bottom: 1px solid var(--border); }
}
.price-card-hero { background: var(--surface-alt); }
.price-tag {
  font-size: 12px;
  color: var(--text3);
  letter-spacing: 2px;
  margin-bottom: 8px;
}
.price-num {
  font-family: var(--serif);
  font-size: 32px;
  font-weight: 400;
  margin-bottom: 10px;
  color: var(--text);
  line-height: 1.2;
}
.price-strike {
  font-size: 16px;
  color: var(--text3);
  text-decoration: line-through;
  text-decoration-color: rgba(0,0,0,0.35);
  margin-left: 8px;
  font-weight: 300;
}
.price-card-hero .price-tag {
  color: var(--ink-red);
  font-weight: 500;
}
.price-card p { font-size: 12.5px; color: var(--text3); margin: 0; line-height: 1.8; }

/* ── 四条承诺 ── */
.four-pledges {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 28px 32px;
}
.four-pledges h3 {
  font-family: var(--serif);
  font-size: 18px;
  font-weight: 500;
  margin: 0 0 14px;
}
.four-pledges ul {
  list-style: disc;
  margin: 0; padding-left: 22px;
}
.four-pledges li {
  font-size: 14px;
  color: var(--text2);
  padding: 6px 0;
  line-height: 1.8;
}

.buy-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 18px;
}
@media (max-width: 720px) { .buy-grid { grid-template-columns: 1fr; } }

.contact-list { list-style: none; padding: 0; }
.contact-list li { font-size: 14.5px; color: var(--text2); padding: 8px 0; }

/* ── Safe harbor 免责声明 ── */
.disclaimer {
  border-top: 1px solid var(--hairline);
  padding-top: 32px;
  padding-bottom: 32px;
}
.disclaimer-text {
  font-size: 12.5px;
  color: var(--text3);
  line-height: 1.9;
  margin: 0;
  letter-spacing: 0.2px;
}
.disclaimer-text b { color: var(--text2); font-weight: 500; margin-right: 6px; }
.disclaimer-text a { color: var(--text2); border-bottom: 1px solid var(--text-ghost); }

/* ── Footer ── */
.footer {
  background: var(--surface);
  border-top: 1px solid var(--hairline);
  padding: 28px 48px;
  text-align: center;
  font-size: 12.5px;
  color: var(--text3);
}
.footer-row { padding: 4px 0; }
.footer-row a { color: var(--text3); border: 0; }
.footer-row a:hover { color: var(--text); opacity: 1; }
.footer-row .dots { color: var(--text-ghost); margin: 0 6px; }
.footer-icp { margin-top: 4px; font-size: 11.5px; color: var(--text-ghost); }

/* ── 法律页 ── */
.legal {
  max-width: 760px;
  margin: 0 auto;
  padding: 64px 32px;
  font-size: 14.5px;
  color: var(--text2);
  line-height: 1.85;
}
.legal h1 {
  font-family: var(--serif);
  font-size: 32px;
  font-weight: 400;
  margin: 0 0 8px;
}
.legal .updated {
  font-size: 12.5px;
  color: var(--text-ghost);
  letter-spacing: 1px;
  margin: 0 0 36px;
}
.legal h2 {
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 500;
  color: var(--text);
  margin: 36px 0 12px;
}
.legal h3 {
  font-size: 15px;
  font-weight: 500;
  color: var(--text);
  margin: 24px 0 8px;
}
.legal p, .legal li { font-size: 14.5px; line-height: 1.85; }
.legal ul { padding-left: 22px; }
.legal li { padding: 4px 0; }
.legal .back {
  display: inline-block;
  margin-top: 40px;
  font-size: 13px;
  color: var(--text3);
}