:root {
  --bg:#0b1220;
  --panel:#111b2f;
  --panel2:#16233b;
  --text:#eaf0ff;
  --muted:#9fb0d1;
  --brand:#0f62fe;
  --success:#16a34a;
  --warning:#f59e0b;
  --danger:#dc2626;
  --border:rgba(255,255,255,.1);
}
*{box-sizing:border-box}
body{margin:0;font-family:Arial,Helvetica,sans-serif;background:linear-gradient(135deg,#071020,#13213c);color:var(--text)}
a{color:inherit;text-decoration:none}
.login-body{min-height:100vh;display:grid;place-items:center;padding:20px}
.login-card{width:100%;max-width:430px;background:rgba(17,27,47,.95);border:1px solid var(--border);border-radius:22px;padding:32px;box-shadow:0 25px 80px rgba(0,0,0,.35)}
.logo{font-size:28px;font-weight:900;letter-spacing:.5px}
.logo span{color:var(--brand)}
.sub{color:var(--muted);margin-top:6px}
input,select,textarea{width:100%;padding:12px 14px;border-radius:12px;border:1px solid var(--border);background:#0b1220;color:var(--text);outline:none}
textarea{min-height:110px}
label{display:block;margin:14px 0 7px;color:var(--muted);font-size:14px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:0;border-radius:12px;padding:11px 15px;background:var(--brand);color:white;font-weight:700;cursor:pointer}
.btn.secondary{background:#263653}
.btn.danger{background:var(--danger)}
.btn.success{background:var(--success)}
.btn.full{width:100%;margin-top:18px}
.error{background:rgba(220,38,38,.15);border:1px solid rgba(220,38,38,.4);padding:12px;border-radius:12px;margin:15px 0}
.success-box{background:rgba(22,163,74,.15);border:1px solid rgba(22,163,74,.4);padding:12px;border-radius:12px;margin:15px 0}
.layout{display:flex;min-height:100vh}
.sidebar{width:270px;background:rgba(8,14,27,.92);border-right:1px solid var(--border);padding:22px;position:fixed;top:0;bottom:0;left:0}
.sidebar .logo{margin-bottom:25px}
.nav a{display:block;padding:12px 14px;border-radius:12px;color:var(--muted);margin:5px 0}
.nav a:hover,.nav a.active{background:var(--panel2);color:white}
.main{margin-left:270px;width:calc(100% - 270px)}
.topbar{height:70px;border-bottom:1px solid var(--border);display:flex;justify-content:space-between;align-items:center;padding:0 28px;background:rgba(17,27,47,.62);backdrop-filter:blur(10px)}
.content{padding:28px}
.grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px}
.card{background:rgba(17,27,47,.9);border:1px solid var(--border);border-radius:20px;padding:20px;box-shadow:0 15px 45px rgba(0,0,0,.18)}
.stat .num{font-size:34px;font-weight:900;margin-top:6px}
.stat .label{color:var(--muted)}
.table-wrap{overflow:auto}
table{width:100%;border-collapse:collapse}
th,td{text-align:left;padding:13px;border-bottom:1px solid var(--border)}
th{color:var(--muted);font-size:13px;text-transform:uppercase}
.badge{display:inline-block;padding:5px 9px;border-radius:999px;background:#263653;color:white;font-size:12px}
.badge.Open,.badge.Sent{background:#1d4ed8}
.badge.Paid,.badge.active{background:#15803d}
.badge.Overdue,.badge.Urgent{background:#b91c1c}
.badge.Draft,.badge.Waiting{background:#92400e}
.actions{display:flex;gap:8px;flex-wrap:wrap}
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:15px}
hr{border:0;border-top:1px solid var(--border);margin:22px 0}
@media(max-width:900px){
  .sidebar{position:static;width:100%}
  .layout{display:block}
  .main{margin-left:0;width:100%}
  .grid{grid-template-columns:1fr}
  .form-grid{grid-template-columns:1fr}
}