:root{
  --bg:#f4f6fb; --card:#fff; --text:#1d2433; --muted:#6b7385; --line:#e3e7ef;
  --brand:#2f5bea; --brand-d:#2347c4; --ok:#14a05b; --warn:#d98a00; --bad:#d6383a; --info:#1b8fd1;
  --radius:12px;
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font-family:"Noto Sans Bengali","Hind Siliguri","SolaimanLipi",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;font-size:15px;line-height:1.5}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
h1{font-size:22px;margin:6px 0 16px}
h2{font-size:17px;margin:0 0 12px}
h3{font-size:15px;margin:16px 0 8px}
code{background:#eef1f7;padding:1px 6px;border-radius:6px;font-size:13px}
.muted{color:var(--muted)} .small{font-size:13px}
.warn-t{color:var(--warn);font-weight:600} .bad-t{color:var(--bad);font-weight:600}

/* top bar */
.topbar{background:#16203a;color:#fff;display:flex;align-items:center;gap:12px;padding:0 16px;position:sticky;top:0;z-index:10;flex-wrap:wrap}
.brand{font-weight:700;padding:14px 0;white-space:nowrap}
.brand span{opacity:.6;font-weight:400}
.nav{display:flex;gap:2px;flex-wrap:wrap;flex:1}
.nav a{color:#cfd6ea;padding:14px 10px;font-size:14px;border-bottom:3px solid transparent}
.nav a:hover{color:#fff;text-decoration:none}
.nav a.active{color:#fff;border-bottom-color:#6f93ff}
.nav .logout{margin-left:auto}
.menu-btn{display:none;margin-left:auto;background:none;border:0;color:#fff;font-size:22px;cursor:pointer}

.wrap{max-width:1200px;margin:0 auto;padding:20px 16px 40px}
.foot{text-align:center;color:var(--muted);font-size:12px;padding:20px}

/* cards & layout */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;margin-bottom:16px;box-shadow:0 1px 2px rgba(20,30,60,.04)}
.card-head{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:8px}
.card-head h2{margin:0}
.grid2{display:grid;grid-template-columns:3fr 2fr;gap:16px;align-items:start}
.scroll{overflow-x:auto}

/* stats */
.stats{display:grid;grid-template-columns:repeat(5,1fr);gap:12px;margin-bottom:16px}
.stat{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:14px;border-top:4px solid var(--brand)}
.stat b{display:block;font-size:28px;line-height:1.1}
.stat span{color:var(--muted);font-size:13px}
.stat.ok{border-top-color:var(--ok)} .stat.warn{border-top-color:var(--warn)} .stat.bad{border-top-color:var(--bad)} .stat.info{border-top-color:var(--info)}

/* tables */
.tbl{width:100%;border-collapse:collapse;font-size:14px}
.tbl th,.tbl td{text-align:left;padding:8px 10px;border-bottom:1px solid var(--line);vertical-align:middle}
.tbl th{font-size:12.5px;color:var(--muted);font-weight:600;background:#fafbfd;white-space:nowrap}
.tbl tr.dim td{opacity:.55}
.tbl.kv th{width:200px;background:none;color:var(--text)}

/* badges */
.badge{display:inline-block;padding:2px 9px;border-radius:20px;font-size:12px;font-weight:600;background:#eef1f7;color:var(--muted);white-space:nowrap}
.badge.ok{background:#e3f6ec;color:var(--ok)} .badge.warn{background:#fff3dc;color:#a86a00} .badge.bad{background:#fde7e7;color:var(--bad)} .badge.info{background:#e2f2fb;color:var(--info)}

/* forms */
label{display:flex;flex-direction:column;gap:5px;font-size:13.5px;font-weight:600;color:#3a4357}
input,select{font:inherit;padding:9px 11px;border:1px solid #cdd3df;border-radius:8px;background:#fff;color:var(--text);font-weight:400}
input:focus,select:focus{outline:2px solid #bcd0ff;border-color:var(--brand)}
input:disabled{background:#f1f3f7}
.form-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:14px}
.form-grid.one{grid-template-columns:1fr}
.form-grid h3{grid-column:1/-1;margin:6px 0 0}
.full-row,.form-actions{grid-column:1/-1}
fieldset{border:1px solid var(--line);border-radius:8px;padding:10px 14px}
legend{font-size:13.5px;font-weight:600;color:#3a4357;padding:0 6px}
label.check{flex-direction:row;align-items:center;gap:8px;font-weight:400}
label.check.inline{display:inline-flex;margin-right:14px}
.inline-form{display:flex;gap:10px;align-items:flex-end;flex-wrap:wrap}
.inline-form label{min-width:150px}
.btn-row{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px}
.btn-row form{margin:0}

.btn{display:inline-block;font:inherit;font-size:14px;padding:9px 14px;border-radius:8px;border:1px solid #cdd3df;background:#fff;color:var(--text);cursor:pointer;white-space:nowrap}
.btn:hover{background:#f3f5fa;text-decoration:none}
.btn.primary{background:var(--brand);border-color:var(--brand);color:#fff}
.btn.primary:hover{background:var(--brand-d)}
.btn.danger{color:var(--bad);border-color:#f0c2c2}
.btn.danger:hover{background:#fdeeee}
.btn.small{padding:5px 10px;font-size:13px}
.btn.full{width:100%}

/* alerts */
.alert{padding:11px 14px;border-radius:8px;margin-bottom:14px;border:1px solid}
.alert.ok{background:#e9f8f0;border-color:#b7e6cc;color:#0d6b3e}
.alert.warn{background:#fff7e6;border-color:#f3d79c;color:#7a5200}
.alert.bad{background:#fdecec;border-color:#f3b9b9;color:#9c1f21}

/* devices */
.dot{display:inline-block;width:10px;height:10px;border-radius:50%;margin-right:6px;vertical-align:middle}
.dot.on{background:var(--ok);box-shadow:0 0 0 3px #d4f2e2}
.dot.off{background:#b8bfcc}
.dev{padding:8px 0;border-bottom:1px solid var(--line)}
.dev:last-child{border-bottom:0}
.dev-card{border:1px solid var(--line);border-radius:10px;padding:12px;margin-bottom:10px}
.dev-card .inline-form input{padding:5px 8px}

/* login */
.login-box{max-width:400px;margin:60px auto}
.login-box.wide{max-width:560px;margin-top:30px}
.login-box h1{margin-bottom:4px}
.login-box form{display:grid;gap:14px;margin-top:14px}

@media (max-width:900px){
  .grid2{grid-template-columns:1fr}
  .stats{grid-template-columns:repeat(2,1fr)}
  .form-grid{grid-template-columns:1fr}
  .menu-btn{display:block}
  .nav{display:none;flex-basis:100%;flex-direction:column;padding-bottom:8px}
  .nav a{padding:10px 4px;border-bottom:0}
  .nav .logout{margin-left:0}
  body.nav-open .nav{display:flex}
}