* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Segoe UI', system-ui, -apple-system, sans-serif; background: #f5f7fa; color: #1e4b69; }
.container { max-width: 750px; margin: 0 auto; padding: 16px; }
h2 { text-align: center; font-size: 1.3rem; margin-bottom: 4px; }
.subtitle { text-align: center; font-size: 0.8rem; color: #94a3b8; margin-bottom: 16px; }
.tree { display: flex; flex-direction: column; align-items: center; gap: 8px; }
.level { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.two-col { width: 100%; }
.branch { flex: 1; min-width: 250px; }
.branch-line { width: 2px; height: 16px; background: #cbd5e1; }
.tnode { padding: 10px 20px; border-radius: 8px; font-weight: 700; font-size: 0.88rem; text-align: center; cursor: pointer; transition: transform 0.2s, box-shadow 0.2s; }
.tnode:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.12); }
.root { background: #1e4b69; color: #fff; }
.success { background: #dcfce7; color: #166534; border: 2px solid #22c55e; }
.redirect { background: #fef9c3; color: #92400e; border: 2px solid #eab308; }
.client-err { background: #ffedd5; color: #9a3412; border: 2px solid #f97316; }
.server-err { background: #fee2e2; color: #991b1b; border: 2px solid #ef4444; }
.network-err { background: #e0e7ff; color: #3730a3; border: 2px solid #6366f1; }
.detail { display: none; background: #fff; border-radius: 8px; margin-top: 8px; padding: 12px; box-shadow: 0 2px 8px rgba(0,0,0,0.06); }
.detail.visible { display: block; }
.code-item { font-size: 0.8rem; color: #475569; padding: 4px 0; border-bottom: 1px solid #f1f5f9; }
.code-item:last-of-type { border-bottom: none; }
.action { font-size: 0.78rem; color: #1e4b69; font-weight: 600; margin-top: 8px; padding-top: 8px; border-top: 2px solid #e2e8f0; }