:root{--blue:#2563EB;--dark:#111827;--card:#1F2937;--light:#F8FAFC}body{background:var(--light);font-family:Arial,sans-serif}.layout{display:flex;min-height:100vh}.sidebar{width:260px;background:var(--dark);color:#fff;padding:18px;position:fixed;top:0;bottom:0;overflow:auto}.brand{font-size:20px;font-weight:700;margin-bottom:25px}.sidebar a{display:block;color:#d1d5db;text-decoration:none;padding:11px 12px;border-radius:8px;margin-bottom:4px}.sidebar a:hover{background:#1f2937;color:#fff}.main{margin-left:260px;width:calc(100% - 260px)}.topbar{height:60px;background:#fff;display:flex;justify-content:space-between;align-items:center;padding:0 25px;border-bottom:1px solid #e5e7eb}.stat-card{background:linear-gradient(135deg,var(--blue),#1d4ed8);color:white;border-radius:16px;padding:22px;box-shadow:0 10px 20px rgba(0,0,0,.08)}.stat-card h3{font-size:30px;margin:0}.card{border:0;border-radius:14px;box-shadow:0 8px 18px rgba(0,0,0,.06)}.btn-primary{background:var(--blue);border-color:var(--blue)}.footer{text-align:center;padding:16px;color:#6b7280}textarea{min-height:160px}@media(max-width:900px){.sidebar{position:relative;width:100%;height:auto}.layout{display:block}.main{margin-left:0;width:100%}}