:root {
  --primary-color: #3b82f6;
  --primary-hover: #2563eb;
  --bg-color: #f9fafb;
  --card-bg: #ffffff;
  --border-color: #e5e7eb;
  --text-primary: #111827;
  --text-secondary: #6b7280;
  --text-tertiary: #9ca3af;
}

html,body{
  margin:0;
  padding:0;
  font-family:ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif;
  background:var(--bg-color);
  color:var(--text-primary);
  line-height:1.6;
}

.container{
  max-width:840px;
  margin:40px auto;
  padding:0 20px;
}

/* Header */
.header{
  text-align:center;
  margin-bottom:32px;
}

.header h1{
  font-size:32px;
  font-weight:700;
  color:var(--text-primary);
  margin-bottom:8px;
}

.header .subtitle{
  color:var(--text-secondary);
  font-size:14px;
}

/* Navigation */
.nav-card{
  background:var(--card-bg);
  border:1px solid var(--border-color);
  border-radius:12px;
  padding:16px 24px;
  margin-bottom:24px;
  text-align:center;
  box-shadow:0 1px 3px rgba(0,0,0,0.05);
}

.nav-card a{
  color:var(--primary-color);
  text-decoration:none;
  font-weight:500;
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:8px 16px;
  border-radius:8px;
  transition:all 0.2s;
}

.nav-card a:hover{
  background:#eff6ff;
}

/* Intro Card */
.intro-card{
  background:var(--card-bg);
  border:1px solid var(--border-color);
  border-radius:12px;
  padding:24px;
  margin-bottom:24px;
  box-shadow:0 1px 3px rgba(0,0,0,0.05);
}

.intro-card h2{
  font-size:18px;
  font-weight:600;
  color:var(--text-primary);
  margin-top:0;
  margin-bottom:12px;
}

.intro-card p{
  color:var(--text-secondary);
  line-height:1.7;
  margin:8px 0;
}

.intro-card code{
  background:#f3f4f6;
  padding:2px 6px;
  border-radius:4px;
  font-size:13px;
  color:#dc2626;
  font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;
}

/* Steps */
.steps-container{
  display:flex;
  flex-direction:column;
  gap:12px;
}

.step-card{
  background:var(--card-bg);
  border:1px solid var(--border-color);
  border-radius:12px;
  padding:20px;
  box-shadow:0 1px 3px rgba(0,0,0,0.05);
  transition:border-color 0.2s,box-shadow 0.2s,transform 0.2s;
}

.step-card:hover{
  border-color:#bfdbfe;
  box-shadow:0 4px 6px rgba(0,0,0,0.06);
  transform:translateY(-2px);
}

.step-header{
  display:flex;
  align-items:center;
  gap:14px;
  margin-bottom:14px;
}

.step-number{
  flex-shrink:0;
  width:36px;
  height:36px;
  border-radius:50%;
  background:linear-gradient(135deg,var(--primary-color),#60a5fa);
  color:#fff;
  display:flex;
  align-items:center;
  justify-content:center;
  font-weight:700;
  font-size:16px;
  box-shadow:0 2px 4px rgba(59,130,246,0.3);
}

.step-title{
  font-size:17px;
  font-weight:600;
  color:var(--text-primary);
}

.step-content{
  color:var(--text-secondary);
  line-height:1.8;
  font-size:14px;
  padding-left:50px;
}

.step-content p{
  margin:8px 0;
}

.step-content code{
  display:block;
  background:#f8fafc;
  color:var(--primary-color);
  padding:10px 14px;
  border-radius:6px;
  font-family:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,monospace;
  font-size:13px;
  word-break:break-all;
  border:1px solid #e2e8f0;
  margin:8px 0;
}

.step-content a{
  color:var(--primary-color);
  text-decoration:none;
}

.step-content a:hover{
  text-decoration:underline;
}

/* Footer */
.footer{
  text-align:center;
  margin-top:32px;
  padding-top:24px;
  border-top:1px solid var(--border-color);
  color:var(--text-secondary);
  font-size:14px;
}

.footer a{
  color:var(--primary-color);
  text-decoration:none;
  font-weight:500;
}

.footer a:hover{
  text-decoration:underline;
}