* { box-sizing: border-box; margin: 0; padding: 0 }
  body { font-family: 'Inter', system-ui, sans-serif; background: #F8FAFC; color: #1E293B; line-height: 1.7 }
  
  /* ── Hero ── */
  .hero {
    background: linear-gradient(135deg, #0F172A 0%, #1E293B 50%, #312E81 100%);
    padding: 60px 40px 50px; text-align: center; color: white; position: relative; overflow: hidden;
  }
  .hero::before {
    content: ''; position: absolute; inset: 0;
    background: radial-gradient(circle at 30% 20%, rgba(99,102,241,.2) 0%, transparent 50%),
                radial-gradient(circle at 70% 80%, rgba(59,130,246,.15) 0%, transparent 50%);
  }
  .hero > * { position: relative; z-index: 1 }
  .hero-badge { display: inline-flex; align-items: center; gap: 6px; padding: 6px 14px; background: rgba(99,102,241,.2); border: 1px solid rgba(99,102,241,.3); border-radius: 100px; font-size: 12px; font-weight: 600; color: #A5B4FC; margin-bottom: 20px }
  .hero h1 { font-size: 32px; font-weight: 800; letter-spacing: -0.03em; margin-bottom: 12px }
  .hero p { font-size: 15px; color: #94A3B8; max-width: 600px; margin: 0 auto; line-height: 1.7 }

  /* ── Container ── */
  .container { max-width: 900px; margin: 0 auto; padding: 40px 24px 80px }

  /* ── Section ── */
  .section { margin-bottom: 48px }
  .section-label { display: inline-flex; align-items: center; gap: 8px; font-size: 11px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: #6366F1; margin-bottom: 12px }
  .section-label .dot { width: 8px; height: 8px; border-radius: 50%; background: #6366F1 }
  .section h2 { font-size: 22px; font-weight: 800; letter-spacing: -0.02em; color: #0F172A; margin-bottom: 16px }
  .section p { font-size: 14px; color: #475569; margin-bottom: 12px }

  /* ── Flow diagram ── */
  .flow { display: flex; flex-direction: column; gap: 0; }
  .flow-step {
    display: flex; gap: 16px; align-items: flex-start; position: relative;
  }
  .flow-line {
    width: 3px; min-height: 100%; background: #E2E8F0; position: absolute; left: 23px; top: 48px; bottom: -12px;
  }
  .flow-step:last-child .flow-line { display: none }
  .flow-icon {
    width: 48px; height: 48px; border-radius: 14px; display: flex; align-items: center; justify-content: center;
    font-size: 20px; flex-shrink: 0; position: relative; z-index: 1;
  }
  .flow-body { flex: 1; padding-bottom: 28px }
  .flow-body h3 { font-size: 15px; font-weight: 700; color: #0F172A; margin-bottom: 4px }
  .flow-body p { font-size: 13px; color: #64748B; line-height: 1.6 }
  .flow-tag {
    display: inline-block; font-size: 10px; font-weight: 700; padding: 3px 8px; border-radius: 6px;
    text-transform: uppercase; letter-spacing: 0.05em; margin-top: 6px;
  }

  /* ── Cards grid ── */
  .cards { display: grid; grid-template-columns: 1fr 1fr; gap: 14px }
  .card {
    background: white; border: 1.5px solid #E2E8F0; border-radius: 14px; padding: 20px;
    transition: all .2s;
  }
  .card:hover { border-color: #C7D2FE; box-shadow: 0 4px 12px rgba(99,102,241,.08) }
  .card-icon { width: 40px; height: 40px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 18px; margin-bottom: 12px }
  .card h3 { font-size: 14px; font-weight: 700; color: #0F172A; margin-bottom: 6px }
  .card p { font-size: 12.5px; color: #64748B; line-height: 1.6 }
  .card code { background: #F1F5F9; padding: 2px 6px; border-radius: 4px; font-size: 11px; color: #6366F1 }

  /* ── Table ── */
  .schema-table { width: 100%; border-collapse: collapse; font-size: 12.5px; margin-top: 12px }
  .schema-table th { background: #F8FAFC; text-align: left; padding: 8px 12px; font-weight: 700; color: #475569; border-bottom: 2px solid #E2E8F0 }
  .schema-table td { padding: 8px 12px; border-bottom: 1px solid #F1F5F9; color: #334155 }
  .schema-table tr:hover td { background: #FAFBFF }
  .type-badge { font-size: 10px; font-weight: 600; padding: 2px 8px; border-radius: 4px; font-family: monospace }
  .type-varchar { background: #EEF2FF; color: #4338CA }
  .type-decimal { background: #ECFDF5; color: #059669 }
  .type-bigint { background: #FEF3C7; color: #D97706 }
  .type-datetime { background: #FFF1F2; color: #E11D48 }
  .type-tinyint { background: #F0F9FF; color: #0284C7 }

  /* ── Callout ── */
  .callout { padding: 16px 20px; border-radius: 12px; font-size: 13px; margin: 16px 0; display: flex; gap: 12px; align-items: flex-start }
  .callout-info { background: #EEF2FF; border: 1px solid #E0E7FF; color: #3730A3 }
  .callout-warn { background: #FFFBEB; border: 1px solid #FDE68A; color: #92400E }
  .callout-success { background: #ECFDF5; border: 1px solid #A7F3D0; color: #065F46 }
  .callout-icon { font-size: 18px; flex-shrink: 0; margin-top: 1px }

  /* ── Back link ── */
  .back-link {
    display: inline-flex; align-items: center; gap: 6px; font-size: 13px; font-weight: 600;
    color: #6366F1; text-decoration: none; padding: 8px 16px; border-radius: 8px;
    background: #EEF2FF; border: 1px solid #E0E7FF; margin-bottom: 32px; transition: all .15s;
  }
  .back-link:hover { background: #E0E7FF; border-color: #C7D2FE }

  /* ── Reflect loop diagram ── */
  .loop-diagram {
    background: white; border: 1.5px solid #E2E8F0; border-radius: 16px; padding: 28px;
    margin: 20px 0; text-align: center;
  }
  .loop-diagram pre {
    font-family: 'Inter', system-ui; font-size: 13px; color: #475569; line-height: 2;
    text-align: left; max-width: 500px; margin: 0 auto;
  }
  .loop-arrow { color: #6366F1; font-weight: 700 }
  .loop-yes { color: #059669; font-weight: 700 }
  .loop-no { color: #DC2626; font-weight: 700 }