:root{
  --paper:#F5F6F8; --surface:#FFFFFF; --ink:#12151A; --ink-soft:#5B6472;
  --line:#E3E6EA; --accent:#3B4FE0; --accent-ink:#FFFFFF;
  --success:#1F9D55; --warning:#C88719; --danger:#D64545; --muted:#9AA3AC;
  --radius:14px; --shadow:0 1px 2px rgba(18,21,26,.04), 0 6px 20px rgba(18,21,26,.06);
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--paper);color:var(--ink);min-height:100%}
a{color:inherit}
h1,h2,h3{margin:0;letter-spacing:-0.01em}
p{margin:0}
.layout{display:flex;min-height:100dvh}
.sidebar{
  width:220px;flex-shrink:0;background:var(--surface);border-right:1px solid var(--line);
  padding:20px 14px;display:flex;flex-direction:column;gap:4px;position:sticky;top:0;height:100dvh;
}
.brand{font-weight:800;font-size:16px;padding:8px 10px 20px;letter-spacing:-0.02em}
.brand small{display:block;font-weight:500;color:var(--ink-soft);font-size:11px;margin-top:2px}
.nav-link{
  display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:10px;
  color:var(--ink-soft);font-size:14px;font-weight:600;text-decoration:none;
}
.nav-link.active,.nav-link:hover{background:#EEF0FF;color:var(--accent)}
.nav-spacer{flex:1}
.signout{margin-top:auto}
.main{flex:1;min-width:0;padding:28px clamp(16px,4vw,40px);max-width:1100px}
.topbar{display:flex;align-items:center;justify-content:space-between;margin-bottom:22px;gap:12px}
.grid{display:grid;gap:16px}
.grid-4{grid-template-columns:repeat(4,1fr)}
.grid-2{grid-template-columns:repeat(2,1fr)}
@media (max-width:860px){ .grid-4{grid-template-columns:repeat(2,1fr)} .layout{flex-direction:column} .sidebar{position:relative;height:auto;width:100%;flex-direction:row;overflow-x:auto} .brand{display:none} .main{padding:20px 16px} }
.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:18px;box-shadow:var(--shadow)}
.stat{display:flex;flex-direction:column;gap:6px}
.stat .value{font-size:28px;font-weight:800}
.stat .label{font-size:13px;color:var(--ink-soft)}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;border:none;
  border-radius:10px;padding:11px 16px;font-size:14px;font-weight:700;cursor:pointer;
  text-decoration:none;
}
.btn-primary{background:var(--accent);color:var(--accent-ink)}
.btn-secondary{background:#fff;color:var(--ink);border:1px solid var(--line)}
.btn-danger{background:#FDECEC;color:var(--danger)}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn-sm{padding:7px 12px;font-size:13px;border-radius:8px}
table{width:100%;border-collapse:collapse;font-size:14px}
th{text-align:left;color:var(--ink-soft);font-weight:600;font-size:12px;text-transform:none;border-bottom:1px solid var(--line);padding:10px 8px}
td{padding:12px 8px;border-bottom:1px solid var(--line);vertical-align:middle}
tr:last-child td{border-bottom:none}
.chip{display:inline-flex;align-items:center;gap:6px;font-size:12px;font-weight:700;padding:4px 10px;border-radius:999px}
.chip-available{background:#E9F9EF;color:var(--success)}
.chip-assigned{background:#EAF0FF;color:var(--accent)}
.chip-inactive{background:#FFF4E2;color:var(--warning)}
.chip-retired{background:#F1F2F4;color:var(--muted)}
.chip-reserved{background:#F1F2F4;color:var(--ink-soft)}
input,select,textarea{
  width:100%;padding:10px 12px;border-radius:10px;border:1px solid var(--line);
  font-size:14px;background:#fff;color:var(--ink);font-family:inherit;
}
label{display:block;font-size:13px;font-weight:600;color:var(--ink-soft);margin-bottom:6px}
.field{margin-bottom:14px}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:14px}
@media (max-width:600px){.form-row{grid-template-columns:1fr}}
.color-input{display:flex;align-items:center;gap:10px}
.color-input input[type=color]{width:44px;height:38px;padding:2px;flex:none}
.modal-backdrop{
  position:fixed;inset:0;background:rgba(18,21,26,.4);display:flex;align-items:flex-end;
  justify-content:center;z-index:50;
}
@media (min-width:640px){ .modal-backdrop{align-items:center} }
.modal{background:#fff;border-radius:18px 18px 0 0;padding:22px;width:100%;max-width:520px;max-height:92dvh;overflow-y:auto}
@media (min-width:640px){ .modal{border-radius:18px} }
.modal-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px}
.close-x{background:none;border:none;font-size:18px;cursor:pointer;color:var(--ink-soft)}
.hidden{display:none !important}
.muted{color:var(--ink-soft);font-size:13px}
.error-text{color:var(--danger);font-size:13px;margin-top:6px}
.toast{
  position:fixed;bottom:18px;left:50%;transform:translateX(-50%);background:var(--ink);color:#fff;
  padding:12px 18px;border-radius:10px;font-size:14px;box-shadow:var(--shadow);z-index:100;
}
.center-screen{min-height:100dvh;display:flex;align-items:center;justify-content:center;padding:20px}
.auth-card{width:100%;max-width:360px;padding:30px 26px}
.qr-preview{width:100%;aspect-ratio:1;border:1px solid var(--line);border-radius:10px;display:flex;align-items:center;justify-content:center;background:#fff;overflow:hidden}
.qr-preview img{width:100%;height:100%;object-fit:contain}
#reader{width:100%;border-radius:14px;overflow:hidden;border:1px solid var(--line)}