/* ============ DESIGN TOKENS ============ */
:root{
  --brand:#4f46e5; --brand-600:#4338ca; --brand-50:#eef2ff;
  --ok:#059669; --ok-bg:#ecfdf5;
  --warn:#d97706; --warn-bg:#fffbeb;
  --err:#dc2626; --err-bg:#fef2f2;
  --info:#0891b2; --info-bg:#ecfeff;

  --bg:#f5f6fa; --surface:#ffffff; --surface-2:#fafbfc;
  --line:#e5e7eb; --line-2:#eef0f3;
  --text:#111827; --muted:#6b7280; --faint:#9ca3af;

  --r-sm:8px; --r:12px; --r-lg:16px;
  --sh-1:0 1px 2px rgba(16,24,40,.05);
  --sh-2:0 4px 14px rgba(16,24,40,.08);
  --sh-3:0 18px 44px rgba(16,24,40,.16);
  --side:248px; --top:60px;
  --font:"Inter","Segoe UI",system-ui,-apple-system,"Helvetica Neue",Arial,sans-serif;
}
html[data-theme="dark"]{
  --brand:#818cf8; --brand-600:#6366f1; --brand-50:#1e1b4b;
  --ok:#34d399; --ok-bg:#052e26;
  --warn:#fbbf24; --warn-bg:#3a2a06;
  --err:#f87171; --err-bg:#3d1414;
  --info:#22d3ee; --info-bg:#062f36;

  --bg:#0b0f17; --surface:#121826; --surface-2:#0f1420;
  --line:#243044; --line-2:#1b2434;
  --text:#e7ecf3; --muted:#9aa7b8; --faint:#6b7a8f;
  --sh-1:0 1px 2px rgba(0,0,0,.4);
  --sh-2:0 4px 14px rgba(0,0,0,.45);
  --sh-3:0 18px 44px rgba(0,0,0,.6);
}
*{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%}
body{
  font-family:var(--font); background:var(--bg); color:var(--text);
  font-size:14px; line-height:1.55; -webkit-font-smoothing:antialiased;
}
a{color:var(--brand);text-decoration:none}
::selection{background:var(--brand);color:#fff}
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--line);border-radius:8px;border:2px solid var(--bg)}
::-webkit-scrollbar-thumb:hover{background:var(--faint)}

/* ============ LAYOUT ============ */
.topbar{
  position:fixed;inset:0 0 auto 0;height:var(--top);z-index:60;
  display:flex;align-items:center;justify-content:space-between;gap:12px;
  padding:0 16px;background:var(--surface);border-bottom:1px solid var(--line);
}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;letter-spacing:-.02em;font-size:16px}
.brand .logo{
  width:32px;height:32px;border-radius:9px;display:grid;place-items:center;color:#fff;
  background:linear-gradient(135deg,var(--brand),#0ea5e9);box-shadow:var(--sh-1);font-size:15px
}
.brand small{display:block;font-weight:500;font-size:11px;color:var(--muted);letter-spacing:0}
.top-right{display:flex;align-items:center;gap:8px}

.sidebar{
  position:fixed;top:var(--top);bottom:0;left:0;width:var(--side);z-index:50;
  background:var(--surface);border-right:1px solid var(--line);
  padding:12px 10px;overflow-y:auto;transition:transform .22s ease;
}
.side-label{font-size:10.5px;font-weight:700;letter-spacing:.09em;text-transform:uppercase;color:var(--faint);padding:14px 10px 6px}
.nav{
  display:flex;align-items:center;gap:10px;padding:9px 11px;border-radius:var(--r-sm);
  color:var(--muted);font-weight:600;cursor:pointer;user-select:none;font-size:13.5px;
  border:1px solid transparent;transition:.13s;
}
.nav:hover{background:var(--surface-2);color:var(--text)}
.nav.active{background:var(--brand);color:#fff;box-shadow:var(--sh-1)}
.nav .ic{width:18px;text-align:center;font-size:15px}
.nav .pill{margin-left:auto;font-size:11px;font-weight:700;background:var(--err);color:#fff;border-radius:20px;padding:0 6px;min-width:18px;text-align:center}
.nav.active .pill{background:rgba(255,255,255,.28)}

.main{margin-left:var(--side);padding:calc(var(--top) + 20px) 20px 60px;max-width:1500px}
.scrim{position:fixed;inset:0;background:rgba(2,6,23,.5);z-index:45;display:none;backdrop-filter:blur(2px)}
@media(max-width:960px){
  .sidebar{transform:translateX(-100%);box-shadow:var(--sh-3)}
  html.nav-open .sidebar{transform:none}
  .main{margin-left:0;padding:calc(var(--top) + 16px) 12px 60px}
  .scrim.show{display:block}
  .hide-sm{display:none !important}
}
.only-sm{display:none}
@media(max-width:960px){.only-sm{display:inline-flex}}

/* ============ COMPONENTS ============ */
.page-head{display:flex;align-items:flex-start;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-bottom:18px}
.page-head h1{font-size:22px;font-weight:800;letter-spacing:-.02em}
.page-head p{color:var(--muted);font-size:13px;margin-top:2px}
.actions{display:flex;gap:8px;flex-wrap:wrap}

.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--sh-1)}
.card-h{padding:13px 16px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:10px;flex-wrap:wrap}
.card-h h3{font-size:14px;font-weight:700}
.card-b{padding:16px}
.card-b.tight{padding:0}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:7px;
  padding:8px 14px;border-radius:var(--r-sm);border:1px solid var(--line);
  background:var(--surface);color:var(--text);font-weight:600;font-size:13px;font-family:inherit;
  cursor:pointer;white-space:nowrap;transition:.13s;box-shadow:var(--sh-1);
}
.btn:hover{background:var(--surface-2);border-color:var(--faint)}
.btn:active{transform:translateY(1px)}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btn-primary{background:var(--brand);border-color:var(--brand);color:#fff}
.btn-primary:hover{background:var(--brand-600);border-color:var(--brand-600)}
.btn-ok{background:var(--ok);border-color:var(--ok);color:#fff}
.btn-ok:hover{filter:brightness(1.06)}
.btn-warn{background:var(--warn);border-color:var(--warn);color:#fff}
.btn-warn:hover{filter:brightness(1.06)}
.btn-err{background:var(--err);border-color:var(--err);color:#fff}
.btn-err:hover{filter:brightness(1.06)}
.btn-ghost{background:transparent;box-shadow:none}
.btn-sm{padding:5px 9px;font-size:12px;border-radius:7px}
.btn-icon{padding:6px 8px;font-size:13px;line-height:1}
.btn-lg{padding:11px 20px;font-size:14px}

.field{margin-bottom:12px}
.field label{display:block;font-size:12px;font-weight:700;color:var(--muted);margin-bottom:5px}
.inp,select.inp,textarea.inp{
  width:100%;padding:9px 11px;border:1px solid var(--line);border-radius:var(--r-sm);
  background:var(--surface);color:var(--text);font-size:13.5px;font-family:inherit;transition:.13s;
}
.inp:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 3px color-mix(in srgb,var(--brand) 18%,transparent)}
select.inp{cursor:pointer;appearance:none;
  background-image:linear-gradient(45deg,transparent 50%,var(--muted) 50%),linear-gradient(135deg,var(--muted) 50%,transparent 50%);
  background-position:calc(100% - 16px) 50%,calc(100% - 11px) 50%;background-size:5px 5px,5px 5px;background-repeat:no-repeat;padding-right:30px}
.inp-sm{padding:5px 8px;font-size:12.5px;border-radius:7px}
.grid{display:grid;gap:12px}
.g2{grid-template-columns:1fr 1fr}
.g3{grid-template-columns:repeat(3,1fr)}
.g4{grid-template-columns:repeat(4,1fr)}
@media(max-width:820px){.g2,.g3,.g4{grid-template-columns:1fr}}

.switch{display:inline-flex;align-items:center;gap:8px;cursor:pointer;user-select:none}
.switch input{display:none}
.switch .track{width:38px;height:21px;border-radius:20px;background:var(--line);position:relative;transition:.16s;flex:0 0 auto}
.switch .track::after{content:"";position:absolute;top:2px;left:2px;width:17px;height:17px;border-radius:50%;background:#fff;box-shadow:var(--sh-1);transition:.16s}
.switch input:checked + .track{background:var(--ok)}
.switch input:checked + .track::after{transform:translateX(17px)}

.tbl-wrap{overflow-x:auto;-webkit-overflow-scrolling:touch}
table.tbl{width:100%;border-collapse:collapse;font-size:13.5px}
table.tbl th{
  text-align:left;font-weight:700;font-size:11px;letter-spacing:.05em;text-transform:uppercase;color:var(--muted);
  padding:10px 12px;background:var(--surface-2);border-bottom:1px solid var(--line);white-space:nowrap;position:sticky;top:0;z-index:1
}
table.tbl td{padding:9px 12px;border-bottom:1px solid var(--line-2);vertical-align:middle}
table.tbl tbody tr:last-child td{border-bottom:none}
table.tbl tbody tr:hover{background:var(--surface-2)}
table.tbl td.num{color:var(--faint);font-variant-numeric:tabular-nums;width:44px}
.empty{padding:40px 16px;text-align:center;color:var(--faint)}
.empty .big{font-size:34px;opacity:.5;margin-bottom:6px}

.badge{display:inline-flex;align-items:center;gap:4px;padding:2px 8px;border-radius:20px;font-size:11.5px;font-weight:700;border:1px solid transparent;white-space:nowrap}
.b-ok{background:var(--ok-bg);color:var(--ok);border-color:color-mix(in srgb,var(--ok) 30%,transparent)}
.b-warn{background:var(--warn-bg);color:var(--warn);border-color:color-mix(in srgb,var(--warn) 30%,transparent)}
.b-err{background:var(--err-bg);color:var(--err);border-color:color-mix(in srgb,var(--err) 30%,transparent)}
.b-info{background:var(--info-bg);color:var(--info);border-color:color-mix(in srgb,var(--info) 30%,transparent)}
.b-brand{background:var(--brand-50);color:var(--brand);border-color:color-mix(in srgb,var(--brand) 30%,transparent)}
.b-mute{background:var(--surface-2);color:var(--muted);border-color:var(--line)}

.stat{background:var(--surface);border:1px solid var(--line);border-radius:var(--r);padding:14px 16px;box-shadow:var(--sh-1);position:relative;overflow:hidden}
.stat::before{content:"";position:absolute;left:0;top:0;bottom:0;width:3px;background:var(--brand)}
.stat.s-ok::before{background:var(--ok)} .stat.s-warn::before{background:var(--warn)}
.stat.s-info::before{background:var(--info)} .stat.s-err::before{background:var(--err)}
.stat .k{font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.06em;color:var(--muted)}
.stat .v{font-size:27px;font-weight:800;letter-spacing:-.03em;margin-top:2px;font-variant-numeric:tabular-nums}
.stat .s{font-size:11.5px;color:var(--faint)}

.note{display:flex;gap:10px;padding:11px 14px;border-radius:var(--r-sm);font-size:13px;border:1px solid var(--line);background:var(--surface-2);margin-bottom:14px}
.note .ni{flex:0 0 auto;font-size:15px;line-height:1.4}
.note.n-info{background:var(--info-bg);border-color:color-mix(in srgb,var(--info) 25%,transparent);color:var(--text)}
.note.n-warn{background:var(--warn-bg);border-color:color-mix(in srgb,var(--warn) 30%,transparent)}
.note.n-err{background:var(--err-bg);border-color:color-mix(in srgb,var(--err) 30%,transparent)}
.note ul{margin:4px 0 0 16px}
.note li{margin:2px 0}

.bar{height:6px;border-radius:6px;background:var(--line-2);overflow:hidden}
.bar > i{display:block;height:100%;border-radius:6px;background:var(--brand);transition:width .3s}

/* Modal */
.mask{position:fixed;inset:0;background:rgba(2,6,23,.55);backdrop-filter:blur(3px);z-index:100;display:none;align-items:flex-start;justify-content:center;padding:24px 12px;overflow-y:auto}
.mask.show{display:flex}
.modal{
  background:var(--surface);border-radius:var(--r-lg);box-shadow:var(--sh-3);width:100%;max-width:620px;
  border:1px solid var(--line);animation:pop .18s ease;margin:auto
}
.modal.wide{max-width:900px}
@keyframes pop{from{opacity:0;transform:translateY(-12px) scale(.98)}to{opacity:1;transform:none}}
.modal-h{padding:15px 18px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between}
.modal-h h3{font-size:16px;font-weight:800}
.modal-b{padding:18px;max-height:66vh;overflow-y:auto}
.modal-f{padding:13px 18px;border-top:1px solid var(--line);display:flex;justify-content:flex-end;gap:8px;background:var(--surface-2);border-radius:0 0 var(--r-lg) var(--r-lg)}
.x{border:none;background:transparent;color:var(--muted);font-size:20px;cursor:pointer;line-height:1;padding:2px 6px;border-radius:6px}
.x:hover{background:var(--surface-2);color:var(--text)}

/* Toast */
.toasts{position:fixed;bottom:20px;right:20px;z-index:200;display:flex;flex-direction:column;gap:8px;pointer-events:none}
.toast{
  display:flex;align-items:center;gap:9px;padding:11px 15px;border-radius:var(--r-sm);
  background:var(--surface);border:1px solid var(--line);box-shadow:var(--sh-2);
  font-size:13.5px;font-weight:600;min-width:230px;max-width:360px;animation:slide .2s ease;pointer-events:auto;
  border-left:3px solid var(--brand)
}
.toast.t-ok{border-left-color:var(--ok)} .toast.t-err{border-left-color:var(--err)} .toast.t-warn{border-left-color:var(--warn)}
@keyframes slide{from{opacity:0;transform:translateX(28px)}to{opacity:1;transform:none}}
@media(max-width:600px){.toasts{left:12px;right:12px;bottom:12px} .toast{max-width:none}}

/* Loading / gate */
#boot{position:fixed;inset:0;z-index:300;background:var(--bg);display:flex;align-items:center;justify-content:center;flex-direction:column;gap:14px}
.spin{width:34px;height:34px;border:3px solid var(--line);border-top-color:var(--brand);border-radius:50%;animation:sp .7s linear infinite}
@keyframes sp{to{transform:rotate(360deg)}}
#boot .msg{color:var(--muted);font-size:13px;font-weight:600}
.setup{max-width:620px;width:100%}
.code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:12px;background:var(--surface-2);border:1px solid var(--line);border-radius:var(--r-sm);padding:10px;white-space:pre-wrap;word-break:break-all}

.sync{display:flex;align-items:center;gap:6px;font-size:11.5px;font-weight:700;color:var(--muted);padding:4px 9px;border:1px solid var(--line);border-radius:20px;background:var(--surface-2)}
.dot{width:7px;height:7px;border-radius:50%;background:var(--faint)}
.dot.on{background:var(--ok);box-shadow:0 0 0 3px color-mix(in srgb,var(--ok) 22%,transparent)}
.dot.off{background:var(--err)}
.dot.busy{background:var(--warn);animation:blink .8s infinite}
@keyframes blink{50%{opacity:.25}}

.view{display:none;animation:fade .18s ease}
.view.active{display:block}
@keyframes fade{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:none}}
.row-err{background:color-mix(in srgb,var(--err) 8%,transparent) !important}
.sel-err{border-color:var(--err) !important;background:var(--err-bg) !important;color:var(--err) !important;font-weight:700}
.sel-warn{border-color:var(--warn) !important}
.sel-ok{border-color:color-mix(in srgb,var(--info) 45%,transparent)}
.mono{font-variant-numeric:tabular-nums}
.chip{display:inline-block;padding:1px 7px;border-radius:6px;background:var(--surface-2);border:1px solid var(--line);font-size:11.5px;font-weight:600;margin:2px 3px 2px 0}
.right{text-align:right} .center{text-align:center}
.muted{color:var(--muted)} .faint{color:var(--faint)}
.sm{font-size:12px} .b{font-weight:700}
.mt{margin-top:14px} .mb{margin-bottom:14px}
.flex{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.sep{height:1px;background:var(--line);margin:14px 0}
.scroll-y{max-height:420px;overflow-y:auto}

/* ============ SIDEBAR THU GỌN (RAIL) + NÚT DÍNH MÉP ============ */
/* Nút ẩn/hiện menu: dính mép phải thanh menu, giữa theo chiều dọc */
#btnRail{
  position:fixed; top:50%; transform:translateY(-50%);
  left:calc(var(--side) - 13px); z-index:56;
  width:26px; height:56px; padding:0; border:1px solid var(--line); border-radius:9px;
  background:var(--surface); color:var(--muted); box-shadow:var(--sh-2);
  display:inline-flex; align-items:center; justify-content:center; cursor:pointer;
  font-size:12px; font-weight:700; transition:left .22s ease, background .14s, color .14s, border-color .14s;
}
#btnRail:hover{background:var(--brand); color:#fff; border-color:var(--brand)}
@media(min-width:961px){
  html[data-rail="mini"] #btnRail{left:calc(66px - 13px)}
  html[data-rail="mini"] .sidebar{width:66px;padding:12px 8px}
  html[data-rail="mini"] .main{margin-left:66px}
  html[data-rail="mini"] .sidebar .nav{justify-content:center;gap:0;padding:10px 0;font-size:0;position:relative}
  html[data-rail="mini"] .sidebar .nav .ic{font-size:17px}
  html[data-rail="mini"] .sidebar .nav .pill{position:absolute;top:3px;right:8px;font-size:9px;min-width:15px;padding:0 4px}
  html[data-rail="mini"] .sidebar .side-label{text-align:center;padding:12px 0 4px;font-size:0}
  html[data-rail="mini"] .sidebar .side-label::before{content:"•••";font-size:10px;letter-spacing:2px;color:var(--line)}
  html[data-rail="mini"] .sidebar #examPickerSm{display:none}
  /* tooltip khi thu gọn */
  html[data-rail="mini"] .sidebar .nav::after{
    content:attr(data-tip);position:absolute;left:60px;white-space:nowrap;background:var(--text);color:var(--surface);
    padding:5px 9px;border-radius:6px;font-size:12px;font-weight:600;opacity:0;pointer-events:none;transition:.12s;z-index:70;box-shadow:var(--sh-2)}
  html[data-rail="mini"] .sidebar .nav:hover::after{opacity:1}
}
/* Trên điện thoại: menu là ngăn kéo, nút trở thành tay nắm ở mép trái */
@media(max-width:960px){
  #btnRail{left:-3px; width:24px; height:60px}
  html.nav-open #btnRail{left:calc(var(--side) - 13px)}
}

/* ============ CỔNG ĐĂNG NHẬP ============ */
#gate{position:fixed;inset:0;z-index:250;background:var(--bg);display:none;align-items:center;justify-content:center;padding:24px 14px}
#gate.show{display:flex}
.gate-card{width:100%;max-width:400px;animation:pop .2s ease}
.gate-logo{width:56px;height:56px;border-radius:15px;display:grid;place-items:center;color:#fff;font-size:26px;
  background:linear-gradient(135deg,var(--brand),#0ea5e9);box-shadow:var(--sh-2);margin:0 auto 14px}
.gate-card h2{text-align:center;font-size:20px;font-weight:800;letter-spacing:-.02em}
.gate-card p.sub{text-align:center;color:var(--muted);font-size:13px;margin:4px 0 20px}
.pw-wrap{position:relative}
.pw-wrap .eye{position:absolute;right:6px;top:50%;transform:translateY(-50%);border:none;background:transparent;cursor:pointer;font-size:15px;padding:4px 6px;color:var(--muted)}

.acct-menu{position:fixed;z-index:150;background:var(--surface);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--sh-3);min-width:210px;overflow:hidden;display:none;animation:pop .14s ease}
.acct-menu.show{display:block}
.acct-menu .item{display:flex;align-items:center;gap:10px;padding:11px 14px;font-size:13.5px;font-weight:600;cursor:pointer;color:var(--text)}
.acct-menu .item:hover{background:var(--surface-2)}
.acct-menu .item.danger{color:var(--err)}
.acct-menu .head{padding:12px 14px;border-bottom:1px solid var(--line);font-size:12px;color:var(--muted)}
.acct-menu .head b{display:block;color:var(--text);font-size:13.5px}

.seg{display:inline-flex;border:1px solid var(--line);border-radius:var(--r-sm);overflow:hidden;background:var(--surface-2)}
.seg button{border:none;background:transparent;padding:7px 13px;font-size:12.5px;font-weight:700;color:var(--muted);cursor:pointer}
.seg button.on{background:var(--brand);color:#fff}
.pwbar{height:5px;border-radius:5px;background:var(--line-2);overflow:hidden;margin-top:6px}
.pwbar>i{display:block;height:100%;transition:width .2s,background .2s}
/* ============ HỘP HỖ TRỢ ============ */
.support-box{padding:4px 2px}
.sp-name{font-size:18px;font-weight:800;color:var(--text);margin-bottom:10px}
.sp-row{display:flex;align-items:center;gap:10px;padding:7px 0;font-size:14px;color:var(--text);border-top:1px dashed var(--line)}
.sp-row a{color:var(--brand);text-decoration:none;font-weight:600}
.sp-row a:hover{text-decoration:underline}
.sp-ic{width:22px;text-align:center;font-size:16px}

/* ============ TAB CẤU HÌNH ============ */
.stabs{display:flex;gap:6px;margin-bottom:16px;flex-wrap:wrap}
.stab{padding:9px 16px;border-radius:10px;border:1px solid var(--line);background:var(--surface);color:var(--muted);font-weight:700;font-size:13.5px;cursor:pointer;transition:.14s}
.stab:hover{background:var(--surface-2);color:var(--text)}
.stab.on{background:var(--brand);color:#fff;border-color:var(--brand);box-shadow:var(--sh-1)}