/* ============ 首页 ============ */
:root{
  --ink: #111827;
  --ink-2: #4b5563;
  --ink-3: #8b949e;
  --line: #e6e8eb;
  --soft: #f7f8fa;
  --accent: #1f6feb;
}

*{ box-sizing: border-box; }
[hidden]{ display: none !important; }

html{ scroll-behavior: smooth; }

body{
  margin: 0;
  background: #fff;
  color: var(--ink);
  font: 15px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}

.wrap{ max-width: 1040px; margin: 0 auto; padding: 0 24px; }

a{ color: inherit; }

/* 按钮 */
.btn{
  display: inline-flex; align-items: center; justify-content: center;
  height: 34px; padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font-size: 13.5px;
  text-decoration: none;
  cursor: pointer;
  transition: background .15s, border-color .15s, color .15s;
}
.btn:hover{ background: #f6f7f9; border-color: #d5d9df; }
.btn.primary{ background: var(--ink); border-color: var(--ink); color: #fff; font-weight: 500; }
.btn.primary:hover{ background: #1f2937; border-color: #1f2937; }
.btn.ghost{ color: var(--ink-2); }
.btn.lg{ height: 44px; padding: 0 22px; font-size: 15px; border-radius: 10px; }
.btn.block{ width: 100%; margin-top: 18px; }

/* 导航 */
.nav{
  position: sticky; top: 0; z-index: 30;
  height: 60px;
  background: rgba(255,255,255,.88);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav.scrolled{ box-shadow: 0 6px 14px -10px rgba(16,24,40,.30); }
.nav-inner{ display: flex; align-items: center; justify-content: space-between; height: 60px; }
.brand{ display: flex; align-items: center; gap: 9px; text-decoration: none; }
.brand strong{ font-size: 15px; font-weight: 600; letter-spacing: .2px; }
.logo{
  width: 28px; height: 28px;
  display: grid; place-items: center;
  border-radius: 7px;
  background: var(--ink);
  color: #fff;
  font: 700 14px/1 ui-monospace, SFMono-Regular, Menlo, monospace;
}
.brand.small .logo{ width: 24px; height: 24px; font-size: 12px; }
.brand.small strong{ font-size: 13.5px; }

.nav-links{ display: flex; align-items: center; gap: 22px; }
.nav-links a{ font-size: 13.5px; color: var(--ink-2); text-decoration: none; }
.nav-links a:hover{ color: var(--ink); }
.nav-links .btn{ color: #fff; }
.nav-links .btn:hover{ color: #fff; }

/* 语言切换（下拉：语言数量可变，宽度恒定） */
.lang-sel{ display: inline-flex; align-items: center; }
.lang-select{
  height: 30px;
  max-width: 104px;
  padding: 0 22px 0 8px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: #fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'%3E%3Cpath fill='%236e7781' d='M0 0h10L5 6z'/%3E%3C/svg%3E") no-repeat right 8px center;
  color: var(--ink);
  font-size: 12.5px;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  text-overflow: ellipsis;
}
.lang-select:hover{ border-color: #d3d8e0; background-color: #f7f8fa; }
.lang-select:focus{
  outline: none;
  border-color: var(--accent, #1f6feb);
  box-shadow: 0 0 0 3px rgba(31,111,235,.12);
}

/* Hero */
.hero{ padding: 76px 24px 12px; text-align: center; }
.eyebrow{
  margin: 0 0 18px;
  font-size: 12px; letter-spacing: 1.4px; text-transform: uppercase;
  color: var(--ink-3);
}
.hero h1{
  margin: 0;
  font-size: 44px;
  line-height: 1.22;
  font-weight: 650;
  letter-spacing: -.5px;
}
.lede{
  margin: 20px auto 0;
  max-width: 560px;
  font-size: 16.5px;
  line-height: 1.7;
  color: var(--ink-2);
}
.cta{ display: flex; justify-content: center; gap: 12px; margin-top: 30px; flex-wrap: wrap; }
.note{ margin: 16px 0 0; font-size: 12.5px; color: var(--ink-3); }

/* 效果展示 */
.showcase{ padding: 52px 24px 8px; }
.stage{
  border-radius: 14px;
  background: linear-gradient(180deg, #f4f6f8 0%, #eef1f4 100%);
  padding: 40px 24px;
  display: flex; justify-content: center;
}
.paper-demo{
  position: relative;
  width: 340px;
  min-height: 440px;
  padding: 26px 26px 34px;
  background: #fff;
  border-radius: 2px;
  box-shadow: 0 1px 2px rgba(16,24,40,.07), 0 14px 34px rgba(16,24,40,.13);
  text-align: left;
}
.pd-head{
  position: absolute; top: 10px; left: 26px; right: 26px;
  font-size: 8px; color: #b3b9c1; letter-spacing: .3px;
  overflow: hidden; white-space: nowrap; text-overflow: ellipsis;
}
.pd-foot{
  position: absolute; bottom: 10px; left: 0; right: 0;
  text-align: center; font-size: 8px; color: #aeb5bd;
  font-variant-numeric: tabular-nums;
}
.pd-body{ font-size: 11px; line-height: 1.65; color: #24292f; }
.pd-h1{
  font-size: 15px; font-weight: 650; color: #10161d;
  padding-bottom: 5px; margin-bottom: 10px;
  border-bottom: 1px solid #e3e7ec;
}
.pd-quote{
  border-left: 3px solid #d5dae0;
  padding-left: 8px; color: #616b76; margin: 8px 0;
}
.pd-h2{ font-size: 12.5px; font-weight: 620; margin: 12px 0 5px; }
.pd-list{ display: flex; gap: 6px; margin: 3px 0; color: #3d454e; }
.pd-list i{
  flex: 0 0 auto; width: 4px; height: 4px; border-radius: 50%;
  background: #c2c8d0; margin-top: 7px;
}
.pd-code{
  margin: 10px 0;
  padding: 8px 10px;
  border-radius: 5px;
  background: #0d1117;
  font: 9.5px/1.75 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  color: #c9d1d9;
}
.pd-code b{ display: inline-block; width: 14px; color: #4d5866; font-weight: 400; text-align: right; margin-right: 6px; }
.pd-line.hl{ color: #79c0ff; }
.pd-p{ margin: 6px 0 0; color: #3d454e; }

/* 功能卡片 */
.features{
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  padding: 56px 24px 8px;
}
.card{
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
}
.card .ico{
  width: 36px; height: 36px;
  display: grid; place-items: center;
  border-radius: 9px;
  background: var(--soft);
  color: var(--ink);
  margin-bottom: 14px;
}
.card h3{ margin: 0 0 7px; font-size: 15px; font-weight: 600; }
.card p{ margin: 0; font-size: 13.5px; line-height: 1.7; color: var(--ink-2); }

/* 价格 */
.pricing{ padding: 72px 24px 8px; text-align: center; }
.pricing h2, .steps h2{
  margin: 0;
  font-size: 26px; font-weight: 620; letter-spacing: -.2px;
}
.pricing .sub{ margin: 10px 0 30px; font-size: 14px; color: var(--ink-2); }
.plans{
  display: grid; grid-template-columns: 1fr 1fr; gap: 18px;
  max-width: 720px; margin: 0 auto;
  text-align: left;
}
.plan{
  position: relative;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fff;
}
.plan.pro{ border-color: #111827; box-shadow: 0 10px 30px -18px rgba(16,24,40,.35); }
.plan .tag{
  position: absolute; top: -10px; left: 24px;
  padding: 3px 9px;
  border-radius: 20px;
  background: var(--ink); color: #fff;
  font-size: 11px; letter-spacing: .5px;
}
.plan-head{ display: flex; align-items: baseline; justify-content: space-between; }
.plan-head h3{ margin: 0; font-size: 15px; font-weight: 600; }
.price{ font-size: 24px; font-weight: 620; letter-spacing: -.3px; }
.price small{ font-size: 12px; font-weight: 400; color: var(--ink-3); }
.plan ul{ margin: 16px 0 0; padding-left: 18px; }
.plan li{ font-size: 13.5px; line-height: 1.9; color: var(--ink-2); }
.plan li b{ color: var(--ink); }
.soon{
  display: inline-block;
  margin-left: 4px;
  padding: 1px 6px;
  border-radius: 10px;
  background: var(--soft);
  border: 1px solid var(--line);
  color: var(--ink-3);
  font-size: 11px;
  vertical-align: 1px;
}
.fine{ margin: 20px 0 0; font-size: 12px; color: var(--ink-3); }

/* 三步 */
.steps{ padding: 72px 24px 84px; text-align: center; }
.steps-row{
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px;
  margin-top: 26px;
}
.step{ text-align: left; }
.step .num{
  display: grid; place-items: center;
  width: 26px; height: 26px;
  border-radius: 50%;
  background: var(--ink); color: #fff;
  font-size: 12px; font-weight: 600;
  margin-bottom: 12px;
}
.step b{ font-size: 15px; font-weight: 600; }
.step p{ margin: 6px 0 0; font-size: 13.5px; line-height: 1.7; color: var(--ink-2); }

/* 页脚 */
.foot{
  border-top: 1px solid var(--line);
  padding: 34px 0 44px;
  background: #fbfcfd;
}
.foot-inner p{ margin: 8px 0 0; font-size: 13px; color: var(--ink-2); }
.foot-inner .dim{ color: var(--ink-3); font-size: 12.5px; }
.foot-inner .dim a{ color: var(--ink-2); text-decoration: none; }
.foot-inner .dim a:hover{ text-decoration: underline; }

/* 响应式（首页面向访客，简单适配即可） */
@media (max-width: 860px){
  .hero h1{ font-size: 34px; }
  .features, .steps-row{ grid-template-columns: 1fr; }
  .plans{ grid-template-columns: 1fr; }
  .hero{ padding-top: 52px; }
}