:root{--bg: #f8f9fa;--border: #e6e7eb;--text: #222;--muted: #6b7280;--primary: #2563eb}html,body,#root{height:100%}.app{display:flex;min-height:100vh;font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,"Apple Color Emoji","Segoe UI Emoji";color:var(--text)}.sidebar{width:280px;border-right:1px solid var(--border);padding:16px;overflow-y:auto;background:#fff}.sidebar h2{margin:0 0 12px;font-size:18px}.nav{display:flex;flex-direction:column;gap:2px;font-size:14px}.nav a{padding:8px 10px;border-radius:6px;color:var(--text);text-decoration:none;transition:background .2s ease,color .2s ease}.nav a:hover{background:#f3f4f6}.nav a.active{background:#eff6ff;color:var(--primary);font-weight:600}.main{flex:1;padding:16px;background:var(--bg)}.page{margin:0 auto}.page-header{margin-bottom:12px;border-bottom:1px solid var(--border);padding-bottom:12px}.page-title{font-size:20px;margin:0 0 4px}.page-desc{color:var(--muted);margin:0}.page-card{background:#fff;border:1px solid var(--border);border-radius:12px;padding:16px;box-shadow:0 1px 2px #0000000a}