/* BoardPrep design system.
   Layout: desktop = fixed sidebar + glass top bar; phones/tablets (<960px) = compact top bar + bottom tab bar.
   Theme: light (white + royal blue) by default; dark (deep navy) via OS setting or the in-app toggle (html[data-theme]). */
@font-face{font-family:"Jakarta";src:url(../fonts/plus-jakarta-sans-latin.woff2) format("woff2");font-weight:400 800;font-display:swap}
[hidden]{display:none!important}

:root{
  --bg:#f4f7ff; --panel:#ffffff; --panel-2:#eef3ff; --panel-3:#e3ebff;
  --ink:#0a1a3d; --ink-2:#44557d; --ink-3:#7b89ab; --line:#e2e9f7; --line-2:#cfdaf1;
  --brand:#2356e8; --brand-2:#1a45c9; --brand-soft:#e9f0ff; --brand-ink:#ffffff; --sky:#38bdf8;
  --xp:#f5a524; --xp-soft:#fff4dd; --xp-ink:#8a5a00;
  --ok:#119a52; --ok-soft:#e6f7ee; --bad:#e0474c; --bad-soft:#fdecec; --warn:#f59e0b;
  --paper:#ffffff;
  --hero:linear-gradient(135deg,#1638b5 0%,#2356e8 45%,#3b8bf6 100%);
  --shadow-1:0 1px 2px rgba(14,38,104,.06);
  --shadow-2:0 1px 2px rgba(14,38,104,.05),0 10px 30px -8px rgba(14,38,104,.12);
  --shadow-3:0 20px 60px -20px rgba(14,38,104,.35);
  --r-sm:10px; --r:16px; --r-lg:22px;
  --font:"Jakarta",system-ui,-apple-system,"Segoe UI",Roboto,"Noto Sans",Arial,sans-serif;
  --topbar-h:64px; --bnav-h:64px;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#060b18; --panel:#0c1427; --panel-2:#121d36; --panel-3:#18264a;
  --ink:#e9efff; --ink-2:#a9b6d6; --ink-3:#6d7ca3; --line:#1b2745; --line-2:#26365e;
  --brand:#4d7bff; --brand-2:#6d93ff; --brand-soft:#15244d; --sky:#38bdf8;
  --xp-soft:#35280b; --xp-ink:#fbc75d; --ok:#34c77b; --ok-soft:#0d2a1d; --bad:#ff6b6f; --bad-soft:#35151a;
  --hero:linear-gradient(135deg,#0f2a8a 0%,#1d46c9 50%,#2d74e8 100%);
  --shadow-1:0 1px 2px rgba(0,0,0,.4); --shadow-2:0 1px 2px rgba(0,0,0,.35),0 12px 32px -10px rgba(0,0,0,.55); --shadow-3:0 24px 60px -20px rgba(0,0,0,.7);
  color-scheme:dark;
}}
:root[data-theme="dark"]{
  --bg:#060b18; --panel:#0c1427; --panel-2:#121d36; --panel-3:#18264a;
  --ink:#e9efff; --ink-2:#a9b6d6; --ink-3:#6d7ca3; --line:#1b2745; --line-2:#26365e;
  --brand:#4d7bff; --brand-2:#6d93ff; --brand-soft:#15244d; --sky:#38bdf8;
  --xp-soft:#35280b; --xp-ink:#fbc75d; --ok:#34c77b; --ok-soft:#0d2a1d; --bad:#ff6b6f; --bad-soft:#35151a;
  --hero:linear-gradient(135deg,#0f2a8a 0%,#1d46c9 50%,#2d74e8 100%);
  --shadow-1:0 1px 2px rgba(0,0,0,.4); --shadow-2:0 1px 2px rgba(0,0,0,.35),0 12px 32px -10px rgba(0,0,0,.55); --shadow-3:0 24px 60px -20px rgba(0,0,0,.7);
  color-scheme:dark;
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
html,body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.55 var(--font);-webkit-font-smoothing:antialiased}
body{transition:background-color .25s ease,color .25s ease}
a{color:var(--brand);text-decoration:none}
button{font:inherit;cursor:pointer;color:inherit}
:focus-visible{outline:2.5px solid var(--brand);outline-offset:2px;border-radius:8px}
::selection{background:var(--brand-soft)}
h1,h2,h3{margin:0;letter-spacing:-.02em;text-wrap:balance;line-height:1.2}
h1{font-size:clamp(22px,3vw,28px);font-weight:800}
h2{font-size:17px;font-weight:700}
h3{font-size:15px;font-weight:700}
.muted{color:var(--ink-3)}
.small{font-size:13px}

/* ---------- splash (first load) ---------- */
#splash{position:fixed;inset:0;z-index:100;background:var(--bg);display:grid;place-items:center;transition:opacity .35s ease}
#splash.out{opacity:0;pointer-events:none}
.splash-in{display:flex;flex-direction:column;align-items:center;gap:16px}
.splash-bar{width:160px;height:4px;border-radius:9px;background:var(--panel-3);overflow:hidden;position:relative}
.splash-bar::after{content:"";position:absolute;inset:0;width:40%;border-radius:9px;background:var(--brand);animation:slide 1.1s ease-in-out infinite}
@keyframes slide{0%{transform:translateX(-100%)}100%{transform:translateX(260%)}}

/* ---------- shell ---------- */
#app{display:flex;min-height:100vh;min-height:100dvh}
.sidebar{width:264px;flex:none;background:var(--panel);border-right:1px solid var(--line);padding:20px 14px;display:flex;flex-direction:column;gap:18px;position:sticky;top:0;height:100vh;height:100dvh;overflow-y:auto}
.brand{display:flex;gap:11px;align-items:center;padding:2px 8px}
.brand-mark{width:40px;height:40px;border-radius:12px;background:var(--hero);color:#fff;display:grid;place-items:center;font-weight:800;font-size:19px;box-shadow:0 6px 16px -6px rgba(35,86,232,.6)}
.brand-name{font-weight:800;font-size:17px;letter-spacing:-.02em}
.brand-sub{font-size:12px;color:var(--ink-3);font-weight:500}
.class-switch{display:grid;grid-template-columns:1fr 1fr;background:var(--panel-2);border-radius:12px;padding:4px;gap:4px}
.class-switch button{border:0;background:transparent;padding:8px;border-radius:9px;color:var(--ink-2);font-weight:700;font-size:13.5px;transition:.2s}
.class-switch button.on{background:var(--panel);color:var(--brand);box-shadow:var(--shadow-1)}
.nav{display:flex;flex-direction:column;gap:2px}
.nav a{display:flex;gap:12px;align-items:center;padding:10px 12px;border-radius:11px;color:var(--ink-2);font-weight:600;font-size:14.5px;transition:background .15s,color .15s}
.nav a:hover{background:var(--panel-2);color:var(--ink)}
.nav a.on{background:var(--brand-soft);color:var(--brand)}
.nav .ico{width:20px;text-align:center;font-size:15px}
.side-foot{margin-top:auto;display:flex;flex-direction:column;gap:10px}
.admin-link{font-size:12px;color:var(--ink-3);padding:0 10px}
.mini-level{background:var(--panel-2);border-radius:14px;padding:12px 14px;font-size:12.5px}
.main-wrap{flex:1;min-width:0;display:flex;flex-direction:column}
.topbar{display:flex;align-items:center;gap:12px;padding:0 32px;height:var(--topbar-h);position:sticky;top:0;z-index:20;
  background:color-mix(in srgb,var(--bg) 78%,transparent);backdrop-filter:saturate(1.6) blur(14px);-webkit-backdrop-filter:saturate(1.6) blur(14px);border-bottom:1px solid transparent;transition:border-color .2s}
.topbar.scrolled{border-bottom-color:var(--line)}
.icon-btn.menu-btn{display:none}
.top-title{font-weight:800;font-size:19px;letter-spacing:-.02em;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.top-stats{margin-left:auto;display:flex;gap:8px;align-items:center;flex-wrap:nowrap}
.icon-btn{width:40px;height:40px;border-radius:12px;border:1px solid var(--line);background:var(--panel);display:grid;place-items:center;font-size:17px;box-shadow:var(--shadow-1);transition:.2s;flex:none}
.icon-btn:hover{border-color:var(--line-2);transform:translateY(-1px)}
.view{padding:8px 32px 64px;max-width:1240px;width:100%;margin:0 auto;animation:fadeUp .35s ease both}
@keyframes fadeUp{from{opacity:.001;transform:translateY(6px)}to{opacity:1;transform:none}}

/* bottom tab bar (phones/tablets) */
.bnav{display:none}
.backdrop{position:fixed;inset:0;background:rgba(6,11,24,.45);backdrop-filter:blur(2px);z-index:29;opacity:0;pointer-events:none;transition:opacity .2s}
.backdrop.on{opacity:1;pointer-events:auto}

/* ---------- primitives ---------- */
.chip{display:inline-flex;align-items:center;gap:6px;height:34px;padding:0 12px;border-radius:999px;background:var(--panel);border:1px solid var(--line);font-weight:700;font-size:12.5px;white-space:nowrap;box-shadow:var(--shadow-1)}
.chip.xp{background:var(--xp-soft);border-color:transparent;color:var(--xp-ink)}
.chip.fire{background:var(--bad-soft);border-color:transparent;color:var(--bad)}
.grid{display:grid;gap:18px}
.g2{grid-template-columns:repeat(2,minmax(0,1fr))}
.g3{grid-template-columns:repeat(3,minmax(0,1fr))}
.g4{grid-template-columns:repeat(4,minmax(0,1fr))}
.card{background:var(--panel);border:1px solid var(--line);border-radius:var(--r);padding:20px;box-shadow:var(--shadow-2);min-width:0}
.card-h{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:14px;flex-wrap:wrap}
.row{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.spacer{flex:1}
.btn{border:1px solid var(--line);background:var(--panel);color:var(--ink);height:40px;padding:0 16px;border-radius:12px;font-weight:700;font-size:14px;display:inline-flex;gap:8px;align-items:center;justify-content:center;white-space:nowrap;transition:transform .15s,box-shadow .15s,background .15s,border-color .15s;box-shadow:var(--shadow-1)}
.btn:hover{border-color:var(--line-2);transform:translateY(-1px)}
.btn:active{transform:translateY(0)}
.btn.primary{background:var(--brand);border-color:var(--brand);color:#fff;box-shadow:0 8px 20px -8px color-mix(in srgb,var(--brand) 70%,transparent)}
.btn.primary:hover{background:var(--brand-2)}
.btn.ghost{background:transparent;border-color:transparent;box-shadow:none;color:var(--ink-2)}
.btn.ghost:hover{background:var(--panel-2)}
.btn.ok{background:var(--ok);border-color:var(--ok);color:#fff}
.btn.bad{background:var(--bad);border-color:var(--bad);color:#fff}
.btn.warn{background:var(--warn);border-color:var(--warn);color:#241800}
.btn.sm{height:34px;padding:0 12px;font-size:13px;border-radius:10px}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}
.bar{height:8px;background:var(--panel-3);border-radius:99px;overflow:hidden}
.bar>i{display:block;height:100%;background:linear-gradient(90deg,var(--brand),var(--sky));border-radius:99px;transition:width .6s ease}
.bar.xpbar>i{background:linear-gradient(90deg,#f5a524,#fb7a3c)}
.bar.okbar>i{background:linear-gradient(90deg,var(--ok),#4ade80)}
.stat{display:flex;flex-direction:column;gap:2px}
.stat b{font-size:26px;letter-spacing:-.03em;font-variant-numeric:tabular-nums}
.stat span{color:var(--ink-3);font-size:13px}

/* hero */
.hero{position:relative;overflow:hidden;background:var(--hero);color:#fff;border-radius:var(--r-lg);padding:26px 28px;display:flex;gap:22px;align-items:center;flex-wrap:wrap;box-shadow:var(--shadow-3)}
.hero::before{content:"";position:absolute;inset:0;background:radial-gradient(600px 200px at 85% -20%,rgba(255,255,255,.28),transparent 60%),radial-gradient(400px 200px at 0% 120%,rgba(56,189,248,.35),transparent 60%);pointer-events:none}
.hero>*{position:relative}
.hero h1{font-size:clamp(22px,3.2vw,30px);color:#fff}
.hero .sub{opacity:.9;margin-top:6px;max-width:60ch}
.hero .hero-stats{margin-left:auto;display:flex;gap:10px;flex-wrap:wrap}
.hstat{background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.18);backdrop-filter:blur(6px);border-radius:14px;padding:10px 14px;min-width:100px}
.hstat b{display:block;font-size:22px;line-height:1.15;font-variant-numeric:tabular-nums}
.hstat span{font-size:12px;opacity:.88}

/* tiles */
.tile{display:flex;gap:14px;align-items:center;padding:16px;border-radius:var(--r);background:var(--panel);border:1px solid var(--line);color:inherit;box-shadow:var(--shadow-1);transition:transform .18s,box-shadow .18s,border-color .18s}
.tile:hover{transform:translateY(-2px);box-shadow:var(--shadow-2);border-color:var(--line-2)}
.tile .ti{width:44px;height:44px;border-radius:13px;display:grid;place-items:center;font-size:19px;flex:none;color:#fff}
.tile b{display:block;font-size:14.5px}
.tile span{font-size:12.5px;color:var(--ink-3)}
.subj-row{display:grid;grid-template-columns:150px 1fr 46px;gap:12px;align-items:center;padding:8px 0}
.subj-row .nm{font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}

/* tags */
.tag{display:inline-flex;align-items:center;height:24px;padding:0 9px;border-radius:8px;font-size:11.5px;font-weight:700;background:var(--panel-2);color:var(--ink-2);white-space:nowrap}
.tag.mcq{background:#e6f3ff;color:#0b63b6}.tag.ar{background:#efeaff;color:#5b34c9}.tag.short{background:#e3f7ec;color:#137a45}
.tag.long{background:#ffe9ea;color:#b4262c}.tag.case{background:#fff3db;color:#9a5b00}.tag.vsa{background:#e8edff;color:#3346b8}
.tag.dia{background:#ffe8f4;color:#b0206f}.tag.hot{background:#fff0e0;color:#b4520c}.tag.board{background:#e1f7ea;color:#146c3f}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .tag:is(.mcq,.ar,.short,.long,.case,.vsa,.dia,.hot,.board){background:var(--panel-3);color:var(--ink)}}
:root[data-theme="dark"] .tag:is(.mcq,.ar,.short,.long,.case,.vsa,.dia,.hot,.board){background:var(--panel-3);color:var(--ink)}

/* tabs, forms */
.tabs{display:flex;gap:6px;flex-wrap:wrap;margin-bottom:14px}
.tabs button{border:1px solid var(--line);background:var(--panel);height:34px;padding:0 14px;border-radius:999px;font-weight:700;font-size:13px;color:var(--ink-2);transition:.15s}
.tabs button:hover{border-color:var(--line-2)}
.tabs button.on{background:var(--brand);color:#fff;border-color:var(--brand)}
select,input[type=text],input[type=tel],input[type=number],input[type=date],input[type=search],textarea{font:inherit;height:44px;padding:0 12px;border-radius:12px;border:1px solid var(--line-2);background:var(--panel);color:var(--ink);min-width:0;width:100%;transition:border-color .15s,box-shadow .15s}
textarea{height:auto;padding:10px 12px}
select:focus,input:focus,textarea:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 4px color-mix(in srgb,var(--brand) 18%,transparent)}
input[type=checkbox]{width:18px;height:18px;accent-color:var(--brand)}
label.f{display:flex;flex-direction:column;gap:6px;font-size:13px;font-weight:700;color:var(--ink-2)}
.filters{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:12px;margin-bottom:16px}
.pill-select{display:flex;gap:8px;flex-wrap:wrap}
.pill-select button{border:1px solid var(--line-2);background:var(--panel);height:38px;padding:0 14px;border-radius:999px;font-weight:700;font-size:13px;color:var(--ink-2);transition:.15s}
.pill-select button.on{background:var(--brand);border-color:var(--brand);color:#fff}

/* question cards: question images always sit on white "paper", in both themes */
.list{display:flex;flex-direction:column;gap:16px}
.qcard{background:var(--panel);border:1px solid var(--line);border-radius:var(--r);overflow:hidden;box-shadow:var(--shadow-2)}
.qcard .qh{display:flex;gap:6px;align-items:center;flex-wrap:wrap;padding:12px 16px;border-bottom:1px solid var(--line);font-size:12.5px}
.qimg{background:var(--paper);padding:10px;text-align:center}
.qimg img{max-width:100%;height:auto;display:block;margin:0 auto}
:root[data-theme="dark"] .qimg{margin:10px;border-radius:12px}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .qimg{margin:10px;border-radius:12px}}
.qcard .qf{display:flex;gap:8px;align-items:center;flex-wrap:wrap;padding:12px 16px;border-top:1px solid var(--line)}
.ans-box{border-top:1px dashed var(--line-2);background:var(--ok-soft)}
.ans-box .lbl{font-size:12px;font-weight:800;letter-spacing:.04em;color:var(--ok);padding:10px 16px 0}
.paper-row{display:flex;align-items:center;gap:14px;padding:14px 0;border-bottom:1px solid var(--line);flex-wrap:wrap}
.paper-row:last-child{border-bottom:0}
.paper-ico{width:42px;height:48px;border-radius:10px;background:var(--brand-soft);color:var(--brand);display:grid;place-items:center;font-weight:800;font-size:11px;flex:none}
.subj-card{cursor:pointer;transition:transform .15s,border-color .15s}
.subj-card:hover{transform:translateY(-2px);border-color:var(--line-2)}
.subj-card.on{border-color:var(--brand);box-shadow:0 0 0 3px color-mix(in srgb,var(--brand) 20%,transparent),var(--shadow-2)}
.empty{padding:36px;text-align:center;color:var(--ink-3)}
.filter-bar{display:none}

/* charts & gamification */
.heat{display:grid;grid-auto-flow:column;grid-template-rows:repeat(7,12px);gap:3px;overflow-x:auto;padding-bottom:4px}
.heat i{width:12px;height:12px;border-radius:3px;background:var(--panel-3)}
.heat i.l1{background:#bcd2ff}.heat i.l2{background:#7fa6ff}.heat i.l3{background:#3f73f0}.heat i.l4{background:#1a3fbf}
.ring{position:relative;width:120px;height:120px;flex:none}
.ring svg{transform:rotate(-90deg)}
.ring .ring-t{position:absolute;inset:0;display:grid;place-items:center;text-align:center;line-height:1.1}
.ring .ring-t b{font-size:24px}
.badges{display:grid;grid-template-columns:repeat(auto-fill,minmax(92px,1fr));gap:10px}
.badge{text-align:center;padding:12px 6px;border-radius:14px;background:var(--panel-2);font-size:11.5px;font-weight:700;color:var(--ink-3);filter:grayscale(1);opacity:.5}
.badge.got{filter:none;opacity:1;color:var(--ink);background:var(--xp-soft)}
.badge .bi{font-size:26px;display:block;margin-bottom:4px}
.arena-mode{position:relative;overflow:hidden;border-radius:var(--r-lg);padding:22px;color:#fff;min-height:156px;display:flex;flex-direction:column;gap:6px;border:0;text-align:left;box-shadow:var(--shadow-2);transition:transform .18s,box-shadow .18s}
.arena-mode:hover{transform:translateY(-3px);box-shadow:var(--shadow-3)}
.arena-mode b{font-size:18px}.arena-mode .em{font-size:30px}.arena-mode span{opacity:.92;font-size:13px}
.quiz-top{display:flex;align-items:center;gap:12px;margin-bottom:14px;flex-wrap:wrap}
.opts{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;padding:14px}
.opt{padding:14px 16px;border-radius:14px;border:1.5px solid var(--line-2);background:var(--panel);font-weight:800;font-size:17px;color:var(--ink);transition:transform .12s,border-color .12s,background .12s;box-shadow:var(--shadow-1)}
.opt:hover:not(:disabled){border-color:var(--brand);transform:translateY(-1px)}
.opt.right{background:var(--ok);border-color:var(--ok);color:#fff}
.opt.wrong{background:var(--bad);border-color:var(--bad);color:#fff}
.timer{font-variant-numeric:tabular-nums}
.hearts{letter-spacing:2px}
.progress-steps{display:flex;gap:4px}
.progress-steps i{flex:1;height:6px;border-radius:9px;background:var(--panel-3)}
.progress-steps i.done{background:var(--ok)}.progress-steps i.miss{background:var(--bad)}.progress-steps i.cur{background:var(--brand)}
.chap-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:12px}
.chap{padding:14px;border-radius:14px;background:var(--panel-2);display:flex;flex-direction:column;gap:8px;cursor:pointer;border:1px solid transparent;transition:.15s}
.chap:hover{border-color:var(--brand);background:var(--panel)}
.stars{color:var(--xp);letter-spacing:1px}.stars .off{color:var(--line-2)}
.chk-row{display:flex;align-items:center;gap:12px;padding:10px 0;border-bottom:1px solid var(--line)}
.chk-row:last-child{border-bottom:0}
.status-btn{border:1px solid var(--line-2);border-radius:999px;height:28px;padding:0 12px;font-size:12px;font-weight:700;background:var(--panel)}
.status-btn.s1{background:#fff3d6;color:#8a5a00;border-color:transparent}
.status-btn.s2{background:var(--brand-soft);color:var(--brand);border-color:transparent}
.status-btn.s3{background:var(--ok-soft);color:var(--ok);border-color:transparent}
.pomo{font-size:56px;font-weight:800;font-variant-numeric:tabular-nums;letter-spacing:-.04em;text-align:center}
table.t{width:100%;border-collapse:collapse;font-size:13.5px}
table.t th,table.t td{padding:10px;border-bottom:1px solid var(--line);text-align:left}
table.t th{color:var(--ink-3);font-weight:700;font-size:12px;letter-spacing:.02em}
.scroll-x{overflow-x:auto}
.type-row{display:grid;grid-template-columns:1fr 96px;gap:10px;align-items:center;padding:8px 0;border-bottom:1px solid var(--line)}
.type-row small{color:var(--ink-3)}
.plan-item{display:flex;gap:12px;align-items:center;padding:12px 14px;border-radius:14px;background:var(--panel-2);border:1px solid transparent;transition:.15s}
.plan-item:hover{border-color:var(--line-2);background:var(--panel)}
.plan-item .pi{font-size:20px}
.onb{max-width:600px;margin:24px auto}

/* overlays */
.toast{position:fixed;left:50%;bottom:calc(24px + env(safe-area-inset-bottom,0px));transform:translateX(-50%);background:var(--ink);color:var(--panel);padding:12px 18px;border-radius:14px;font-weight:700;z-index:60;box-shadow:var(--shadow-3);max-width:calc(100vw - 32px)}
.modal{position:fixed;inset:0;background:rgba(6,11,24,.55);backdrop-filter:blur(4px);display:grid;place-items:center;z-index:50;padding:16px}
.modal-card{background:var(--panel);border:1px solid var(--line);border-radius:var(--r-lg);padding:24px;max-width:560px;width:100%;max-height:90vh;overflow:auto;box-shadow:var(--shadow-3)}
.xp-pop{position:fixed;right:24px;top:calc(var(--topbar-h) + 10px);background:linear-gradient(90deg,#f5a524,#fb7a3c);color:#fff;font-weight:800;padding:8px 16px;border-radius:999px;z-index:60;box-shadow:0 10px 24px -8px rgba(245,120,36,.6);animation:pop 1.4s ease forwards}
@keyframes pop{0%{transform:translateY(10px);opacity:0}15%{transform:none;opacity:1}80%{opacity:1}100%{transform:translateY(-20px);opacity:0}}

/* ---------- responsive ---------- */
@media (max-width:1280px){.g4{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:1100px){
  :root{--topbar-h:58px}
  .sidebar{position:fixed;left:0;top:0;bottom:0;z-index:30;transform:translateX(-105%);transition:transform .25s ease;box-shadow:var(--shadow-3);padding-top:calc(20px + env(safe-area-inset-top,0px));padding-bottom:calc(20px + env(safe-area-inset-bottom,0px))}
  .sidebar.open{transform:none}
  .topbar{padding:0 16px;padding-top:env(safe-area-inset-top,0px);height:calc(var(--topbar-h) + env(safe-area-inset-top,0px))}
  .top-title{font-size:17px}
  .top-stats .chip.hide-sm{display:none}
  .view{padding:6px 16px calc(var(--bnav-h) + 28px + env(safe-area-inset-bottom,0px))}
  .g2{grid-template-columns:1fr}
  .g3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .g3>:last-child:nth-child(odd){grid-column:1/-1}
  .hero{padding:22px 20px;border-radius:20px}
  .hero .hero-stats{margin-left:0;width:100%;display:grid;grid-template-columns:repeat(4,1fr)}
  .opts{grid-template-columns:repeat(2,1fr)}
  .bnav{display:grid;grid-template-columns:repeat(5,1fr);position:fixed;left:0;right:0;bottom:0;z-index:25;
    padding:6px 8px calc(6px + env(safe-area-inset-bottom,0px));background:color-mix(in srgb,var(--panel) 88%,transparent);
    backdrop-filter:saturate(1.6) blur(16px);-webkit-backdrop-filter:saturate(1.6) blur(16px);border-top:1px solid var(--line)}
  .bnav a,.bnav button{display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;height:52px;border:0;background:transparent;border-radius:12px;color:var(--ink-3);font-size:11px;font-weight:700}
  .bnav .bi{font-size:19px;line-height:1}
  .bnav a.on{color:var(--brand)}
  .bnav a.on .bi{transform:translateY(-1px)}
  .toast{bottom:calc(var(--bnav-h) + 18px + env(safe-area-inset-bottom,0px))}
}
@media (max-width:700px){
  .g3{grid-template-columns:1fr}
  .hero .hero-stats{grid-template-columns:repeat(auto-fit,minmax(68px,1fr));gap:8px}
  .hstat{min-width:0;padding:9px 10px}
  .hstat b{font-size:19px}
  .filter-bar{display:flex;align-items:center;justify-content:space-between;margin-bottom:12px}
  .filter-panel{display:none}
  .filter-panel.open{display:block}
  .hide-mobile{display:none}
}
@media (max-width:560px){
  body{font-size:14.5px}
  .card{padding:16px;border-radius:14px}
  .g4{grid-template-columns:1fr 1fr;gap:12px}
  .subj-row{grid-template-columns:104px 1fr 40px}
  .paper-row .btn{flex:1}
  .chip{height:32px;padding:0 10px}
  .top-stats .chip.xp{display:none}
  .filters{grid-template-columns:1fr 1fr}
}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important}}

/* line icons */
svg.i{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.9;stroke-linecap:round;stroke-linejoin:round;flex:none}
.bnav svg.i{width:22px;height:22px}
.nav a.on svg.i{stroke-width:2.2}

/* sign-up screen: no navigation until the account exists */
body.onb-mode .sidebar,body.onb-mode .bnav,body.onb-mode #topStats{display:none}
body.onb-mode .view{padding-bottom:48px}
body.onb-mode #themeBtn{margin-left:auto}