:root {
  --accent:#2E7DFA; --accent-soft:#E8F0FE; --bg:#F7F8FA; --card:#FFFFFF;
  --text:#1F2937; --muted:#6B7280; --radius:16px; --shadow:0 8px 24px rgba(0,0,0,.06);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;background:var(--bg);color:var(--text)}
a{color:var(--accent);text-decoration:none}
.app{display:grid;grid-template-columns:260px 1fr;min-height:100vh}
.sidebar{background:#fff;border-right:1px solid #eee;padding:24px;position:sticky;top:0;height:100vh}
.brand{font-weight:800;font-size:22px;margin-bottom:24px;letter-spacing:.5px}
.sidebar nav a{display:block;padding:10px 12px;border-radius:10px;color:var(--text);margin-bottom:6px;transition:background .2s, transform .05s}
.sidebar nav a:hover{background:var(--accent-soft);transform:translateY(-1px)}
.sidebar nav a.muted{color:var(--muted)}
.content{display:flex;flex-direction:column}
.topbar{display:flex;align-items:center;justify-content:space-between;padding:16px 24px}
.topbar-title{font-size:20px;font-weight:700}
.page{padding:0 24px 24px}
.footer{padding:24px;color:var(--muted)}
.flash{margin:0 24px 16px;padding:12px 14px;border-radius:12px;box-shadow:var(--shadow);background:#ecfdf5;color:#065f46}
.flash.danger{background:#fef2f2;color:#991b1b}
.flash.warning{background:#fffbeb;color:#92400e}
.card{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px;margin-top:24px}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}
.grid-2{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.grid-3{display:grid;grid-template-columns:1fr 1fr 1fr;gap:16px}
table{width:100%;border-collapse:collapse}
th,td{text-align:left;padding:10px 8px;border-bottom:1px solid #eee}
h1,h2,h3{margin:0 0 12px}
input,select,textarea,button{width:100%;padding:10px 12px;border-radius:12px;border:1px solid #e5e7eb;outline:none}
button{background:var(--accent);color:#fff;border:none;cursor:pointer;font-weight:700}
button:hover{filter:brightness(.95)}
label{display:block;font-size:12px;color:var(--muted);margin-bottom:6px}
label input,label select,label textarea{margin-top:6px}
.auth-card{max-width:420px;margin:64px auto;background:var(--card);padding:24px;border-radius:var(--radius);box-shadow:var(--shadow)}
.stats-row{display:flex;gap:16px}
.stat{background:var(--accent-soft);padding:16px;border-radius:14px;flex:1;text-align:center}
.stat-num{font-size:24px;font-weight:800}
.inline-form input,.inline-form select{width:auto;display:inline-block;margin-right:6px}
#tree ul{list-style:none;padding-left:24px}
#tree li{position:relative;margin:6px 0}
#tree li::before{content:'';position:absolute;left:-14px;top:12px;width:10px;height:1px;background:#ddd}