:root{
  --bg:#ffffff;
  --bg-soft:#f7f8fc;
  --text:#1f2430;
  --muted:#5b6478;
  --line:#e6e8f0;
  --brand:#5b5bd6;
  --brand-soft:#eef0ff;
  --accent:#f4f1ff;
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  background:var(--bg);
  color:var(--text);
  line-height:1.75;
  font-size:16px;
}
.wrap{max-width:820px;margin:0 auto;padding:0 20px}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
code{
  background:var(--accent);color:var(--brand);
  padding:2px 7px;border-radius:5px;font-size:.92em;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}

/* header */
.site-header{border-bottom:1px solid var(--line);background:#fff;position:sticky;top:0;z-index:10}
.site-header .wrap{display:flex;align-items:center;justify-content:space-between;height:60px}
.brand{font-weight:700;font-size:18px;color:var(--text)}
.brand span{color:var(--brand)}
.nav a{margin-left:18px;color:var(--muted);font-size:15px}
.nav a:hover{color:var(--brand)}
.nav a.lang{
  color:var(--brand);font-weight:600;font-size:13px;
  border:1px solid var(--line);border-radius:6px;padding:2px 9px;margin-left:16px;
}
.nav a.lang:hover{background:var(--brand);color:#fff;border-color:var(--brand);text-decoration:none}

/* hero */
.hero{padding:56px 0 44px;background:linear-gradient(180deg,var(--bg-soft),#fff);border-bottom:1px solid var(--line)}
.kicker{
  display:inline-block;background:var(--brand-soft);color:var(--brand);
  font-size:13px;padding:4px 12px;border-radius:999px;margin:0 0 16px;
}
h1{font-size:32px;line-height:1.35;margin:0 0 18px;letter-spacing:-.2px}
h1 .code{
  background:linear-gradient(135deg,#5b5bd6,#8b5cf6);color:#fff;
  padding:2px 14px;border-radius:8px;letter-spacing:2px;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
.lead{font-size:17px;color:var(--muted);margin:0 0 28px}

.code-card{
  background:#fff;border:1px solid var(--line);border-radius:14px;
  padding:24px;text-align:center;box-shadow:0 6px 20px rgba(31,36,48,.06);
  margin-bottom:26px;
}
.code-label{font-size:13px;color:var(--muted);letter-spacing:2px}
.code-value{
  font-size:40px;font-weight:700;letter-spacing:6px;color:var(--brand);
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  margin:6px 0 14px;
}
.copy-btn{
  border:1px solid var(--brand);background:#fff;color:var(--brand);
  padding:9px 22px;border-radius:8px;cursor:pointer;font-size:15px;
  font-family:inherit;transition:.15s;
}
.copy-btn:hover{background:var(--brand);color:#fff}
.code-hint{margin:14px 0 0;font-size:14px;color:var(--muted)}

.cta{
  display:inline-block;background:var(--brand);color:#fff;
  padding:14px 32px;border-radius:10px;font-size:17px;font-weight:600;
  box-shadow:0 6px 18px rgba(91,91,214,.28);
}
.cta:hover{background:#4a4ac4;text-decoration:none}
.cta-note{font-size:13px;color:var(--muted);margin:12px 0 0}

/* steps */
.steps{padding:48px 0}
.steps h2,.detail h2{font-size:24px;margin:0 0 24px}
.step-list{list-style:none;margin:0;padding:0}
.step-list li{
  position:relative;padding:0 0 22px 46px;border-left:2px solid var(--line);margin-left:12px;
}
.step-list li:last-child{border-left-color:transparent;padding-bottom:0}
.step-list .num{
  position:absolute;left:-17px;top:0;
  width:32px;height:32px;border-radius:50%;
  background:var(--brand);color:#fff;
  display:flex;align-items:center;justify-content:center;
  font-size:15px;font-weight:600;
}
.step-list h3{font-size:17px;margin:4px 0 6px}
.step-list p{margin:0;color:var(--muted);font-size:15px}

/* detail */
.detail{padding:8px 0 56px;border-top:1px solid var(--line)}
.detail h2{padding-top:40px}
.qa{margin-bottom:24px}
.qa h3{font-size:17px;margin:0 0 6px}
.qa p{margin:0;color:var(--muted);font-size:15px}
.more{font-size:15px;color:var(--muted);margin-top:28px}

/* footer */
.site-footer{border-top:1px solid var(--line);background:var(--bg-soft);padding:32px 0;font-size:13px;color:var(--muted)}
.site-footer p{margin:4px 0}
.foot-links a{color:var(--muted)}

@media (max-width:600px){
  h1{font-size:25px}
  .code-value{font-size:32px;letter-spacing:4px}
  .site-header .wrap{height:auto;flex-direction:column;align-items:flex-start;padding:12px 20px}
  .nav a{margin:0 14px 0 0}
  .site-header{position:static}
}