/* STUDY.KYTVK — Mobile-First CSS v2.0 */
@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:ital,wght@0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,400&display=swap');

:root {
  --pri:#1e3a5f; --pri-d:#0f2040; --pri-l:#2d5a8e;
  --acc:#0ea5e9; --acc-d:#0284c7;
  --ok:#10b981;  --warn:#f59e0b; --err:#ef4444; --pur:#8b5cf6;
  --bg:#f0f4f8;  --card:#fff;
  --txt:#1a202c; --txt2:#4a5568; --txt3:#718096;
  --bdr:#e2e8f0; --bdr2:#cbd5e0;
  --sh:0 1px 3px rgba(0,0,0,.08),0 1px 2px rgba(0,0,0,.05);
  --sh2:0 4px 16px rgba(30,58,95,.12);
  --sh3:0 10px 40px rgba(30,58,95,.18);
  --r:12px; --rs:8px; --rl:20px; --rxl:28px;
  --font:'Be Vietnam Pro',system-ui,sans-serif;
  --nh:60px; --tr:.18s ease;
}
[data-theme=dark]{
  --bg:#0f172a; --card:#1e293b;
  --txt:#f1f5f9; --txt2:#cbd5e1; --txt3:#94a3b8;
  --bdr:#334155; --bdr2:#475569;
  --sh:0 1px 3px rgba(0,0,0,.3),0 1px 2px rgba(0,0,0,.2);
  --sh2:0 4px 16px rgba(0,0,0,.4); --sh3:0 10px 40px rgba(0,0,0,.5);
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-tap-highlight-color:transparent;text-size-adjust:100%}
body{font-family:var(--font);background:var(--bg);color:var(--txt);line-height:1.65;font-size:15px;overflow-x:hidden;min-height:100vh;padding-top:var(--nh);transition:background var(--tr),color var(--tr)}
img{max-width:100%;height:auto;display:block}
a{color:var(--acc);text-decoration:none}
a:hover{color:var(--acc-d)}
button,input,select,textarea{font-family:var(--font)}
::-webkit-scrollbar{width:4px;height:4px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--bdr2);border-radius:2px}

/* ─ NAVBAR ─────────────────────────────────────────────── */
.nav{position:fixed;top:0;inset-inline:0;z-index:1000;height:var(--nh);background:var(--pri);display:flex;align-items:center;padding:0 1rem;gap:.75rem;box-shadow:0 2px 20px rgba(0,0,0,.25)}
.nav-brand{display:flex;align-items:center;gap:.55rem;color:#fff;font-weight:900;font-size:1.05rem;letter-spacing:-.3px;flex-shrink:0}
.nav-logo{width:32px;height:32px;background:var(--acc);border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:.8rem;font-weight:900;color:#fff;box-shadow:0 2px 8px rgba(14,165,233,.5);flex-shrink:0}
.nav-sub{font-size:.7rem;opacity:.7;display:none}
.nav-gap{flex:1}
.nav-actions{display:flex;align-items:center;gap:.35rem}
.nav-ico{width:36px;height:36px;border-radius:8px;background:rgba(255,255,255,.1);border:none;color:#fff;font-size:.9rem;display:flex;align-items:center;justify-content:center;cursor:pointer;text-decoration:none;position:relative;transition:background var(--tr);flex-shrink:0}
.nav-ico:hover{background:rgba(255,255,255,.2);color:#fff}
.notif-dot{position:absolute;top:5px;right:5px;width:8px;height:8px;background:var(--err);border-radius:50%;border:2px solid var(--pri)}
.nav-burger{display:flex;flex-direction:column;gap:4px;background:none;border:none;padding:.4rem;cursor:pointer}
.nav-burger span{display:block;width:20px;height:2px;background:#fff;border-radius:2px;transition:all .3s}
.nav-burger.open span:nth-child(1){transform:rotate(45deg) translate(4px,4px)}
.nav-burger.open span:nth-child(2){opacity:0}
.nav-burger.open span:nth-child(3){transform:rotate(-45deg) translate(4px,-4px)}
/* Drawer */
.drawer-overlay{position:fixed;inset:0;top:var(--nh);background:rgba(0,0,0,.55);z-index:999;display:none;backdrop-filter:blur(3px)}
.drawer-overlay.open{display:block}
.drawer{position:fixed;top:var(--nh);left:0;bottom:0;width:min(280px,80vw);background:var(--pri-d);z-index:1000;transform:translateX(-100%);transition:transform .3s cubic-bezier(.4,0,.2,1);overflow-y:auto;display:flex;flex-direction:column}
.drawer.open{transform:none}
.drawer-body{flex:1;padding:.75rem 0}
.drawer-footer{padding:1rem;border-top:1px solid rgba(255,255,255,.1)}
.d-item{display:flex;align-items:center;gap:.75rem;padding:.75rem 1.25rem;color:rgba(255,255,255,.8);font-size:.88rem;font-weight:500;transition:background .15s;border-left:3px solid transparent;text-decoration:none}
.d-item:hover,.d-item.on{background:rgba(255,255,255,.08);color:#fff;border-left-color:var(--acc)}
.d-item i{width:17px;text-align:center;font-size:.88rem;opacity:.75;flex-shrink:0}
.d-item.on i{opacity:1;color:var(--acc)}
.d-sep{font-size:.68rem;font-weight:700;letter-spacing:1.5px;color:rgba(255,255,255,.35);padding:.6rem 1.25rem .2rem;text-transform:uppercase}
.d-divider{height:1px;background:rgba(255,255,255,.08);margin:.4rem 0}
/* User dropdown */
.ud-wrap{position:relative}
.ud-avatar{width:32px;height:32px;border-radius:50%;background:var(--acc);color:#fff;font-weight:900;font-size:.78rem;display:flex;align-items:center;justify-content:center;cursor:pointer;border:none;flex-shrink:0}
.ud-menu{position:absolute;top:calc(100% + 8px);right:0;background:var(--card);border:1px solid var(--bdr);border-radius:var(--r);box-shadow:var(--sh3);min-width:190px;display:none;overflow:hidden;z-index:200;animation:fdwn .18s ease}
@keyframes fdwn{from{opacity:0;transform:translateY(-6px)}to{opacity:1;transform:none}}
.ud-menu.show{display:block}
.ud-head{padding:.85rem 1rem;border-bottom:1px solid var(--bdr)}
.ud-head strong{display:block;font-size:.875rem;color:var(--txt)}
.ud-head span{font-size:.75rem;color:var(--txt3)}
.ud-link{display:flex;align-items:center;gap:.6rem;padding:.6rem 1rem;font-size:.85rem;color:var(--txt);transition:background .15s}
.ud-link:hover{background:var(--bg)}
.ud-link i{width:14px;text-align:center;color:var(--txt3)}
.ud-link.red{color:var(--err)}
.ud-link.red i{color:var(--err)}
.ud-divider{height:1px;background:var(--bdr)}

/* ─ CONTAINER ──────────────────────────────────────────── */
.wrap{width:100%;max-width:1200px;margin:0 auto;padding:0 1rem}
.wrap-sm{max-width:640px;margin:0 auto;padding:0 1rem}
.sec{padding:1.75rem 0}

/* ─ PAGE HEADER ─────────────────────────────────────────── */
.ph{background:linear-gradient(135deg,var(--pri) 0%,var(--pri-l) 100%);color:#fff;padding:1.5rem 0 1.75rem}
.ph h1{font-size:1.45rem;font-weight:800;line-height:1.25;margin-bottom:.2rem}
.ph p{font-size:.83rem;opacity:.85}
.bc{display:flex;flex-wrap:wrap;align-items:center;gap:.25rem;list-style:none;font-size:.75rem;opacity:.7;margin-bottom:.4rem}
.bc a{color:rgba(255,255,255,.8)}
.bc a:hover{color:#fff}
.bc li+li::before{content:'›';margin-right:.2rem}

/* ─ CARDS ───────────────────────────────────────────────── */
.card{background:var(--card);border-radius:var(--r);box-shadow:var(--sh);border:1px solid var(--bdr);overflow:hidden;transition:box-shadow var(--tr),transform var(--tr)}
.card:hover{box-shadow:var(--sh2)}
.card-hd{padding:.9rem 1.1rem;border-bottom:1px solid var(--bdr);display:flex;align-items:center;justify-content:space-between;gap:.75rem}
.card-title{font-size:.9rem;font-weight:700;color:var(--pri);display:flex;align-items:center;gap:.5rem}
[data-theme=dark] .card-title{color:var(--txt)}
.card-bd{padding:1.1rem}
.card-ft{padding:.75rem 1.1rem;border-top:1px solid var(--bdr);background:rgba(0,0,0,.02)}
[data-theme=dark] .card-ft{background:rgba(255,255,255,.02)}

/* ─ HERO ─────────────────────────────────────────────────── */
.hero{background:linear-gradient(135deg,var(--pri-d) 0%,var(--pri) 55%,#1a6ba0 100%);color:#fff;padding:2.5rem 1rem 3.5rem;text-align:center;position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;inset:0;background:url("data:image/svg+xml,%3Csvg width='50' height='50' viewBox='0 0 50 50' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='%23fff' fill-opacity='.04'%3E%3Ccircle cx='25' cy='25' r='6'/%3E%3C/g%3E%3C/svg%3E")}
.hero-tag{display:inline-block;background:rgba(14,165,233,.25);border:1px solid rgba(14,165,233,.4);color:rgba(255,255,255,.9);padding:.25rem .85rem;border-radius:20px;font-size:.72rem;font-weight:700;letter-spacing:.5px;margin-bottom:.75rem;text-transform:uppercase}
.hero h1{font-size:clamp(1.6rem,6vw,3rem);font-weight:900;line-height:1.15;margin-bottom:.6rem;position:relative}
.hero h1 .hl{color:var(--acc)}
.hero p{font-size:.9rem;opacity:.88;max-width:500px;margin:0 auto 1.5rem;position:relative}
.hero-cta{display:flex;gap:.65rem;justify-content:center;flex-wrap:wrap;position:relative;margin-bottom:2.5rem}
.hero-stats{display:grid;grid-template-columns:repeat(2,1fr);gap:.65rem;position:relative}
.hs{background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.12);border-radius:var(--r);padding:.85rem .65rem;text-align:center}
.hs .n{font-size:1.7rem;font-weight:900;color:var(--acc);line-height:1}
.hs .l{font-size:.7rem;opacity:.8;margin-top:.15rem}

/* ─ SUBJECT GRID ────────────────────────────────────────── */
.subj-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:.65rem}
.subj-card{background:var(--card);border-radius:var(--r);border:1px solid var(--bdr);box-shadow:var(--sh);padding:.9rem;text-decoration:none;color:var(--txt);display:block;transition:all .2s;position:relative;overflow:hidden}
.subj-card::before{content:'';position:absolute;left:0;top:0;bottom:0;width:3px;background:var(--sc,var(--acc))}
.subj-card:hover{transform:translateY(-2px);box-shadow:var(--sh2);border-color:var(--sc,var(--acc))}
.subj-ico{width:38px;height:38px;border-radius:10px;background:var(--sc,var(--acc));color:#fff;font-size:1rem;display:flex;align-items:center;justify-content:center;margin-bottom:.55rem;box-shadow:0 3px 8px rgba(0,0,0,.15)}
.subj-card h3{font-size:.83rem;font-weight:700;margin-bottom:.15rem;line-height:1.3}
.subj-card .sc-desc{font-size:.72rem;color:var(--txt3);line-height:1.4;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.subj-meta{font-size:.7rem;color:var(--sc,var(--acc));font-weight:700;margin-top:.45rem}

/* ─ EXAM CARDS ──────────────────────────────────────────── */
.exam-grid{display:grid;grid-template-columns:1fr;gap:.9rem}
.ec{background:var(--card);border-radius:var(--r);box-shadow:var(--sh);border:1px solid var(--bdr);overflow:hidden;transition:all .2s;display:flex;flex-direction:column}
.ec:hover{transform:translateY(-2px);box-shadow:var(--sh2)}
.ec-top{padding:.9rem 1rem 1rem;background:linear-gradient(135deg,var(--ec,var(--pri)),color-mix(in srgb,var(--ec,var(--pri)) 80%,#000));color:#fff;flex-shrink:0}
.ec-subj{display:inline-flex;align-items:center;gap:.3rem;font-size:.68rem;font-weight:700;background:rgba(255,255,255,.2);padding:.15rem .5rem;border-radius:20px;margin-bottom:.45rem;text-transform:uppercase}
.ec-top h3{font-size:.88rem;font-weight:700;line-height:1.4;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.ec-meta{display:grid;grid-template-columns:repeat(3,1fr);border-bottom:1px solid var(--bdr)}
.ec-mc{text-align:center;padding:.55rem .35rem;border-right:1px solid var(--bdr)}
.ec-mc:last-child{border-right:none}
.ec-mc .v{font-size:1rem;font-weight:800;color:var(--pri);display:block;line-height:1.2}
[data-theme=dark] .ec-mc .v{color:var(--acc)}
.ec-mc .l{font-size:.63rem;color:var(--txt3)}
.ec-foot{padding:.65rem .9rem;display:flex;align-items:center;justify-content:space-between;gap:.5rem;flex-wrap:wrap;margin-top:auto}
.ec-creator{font-size:.72rem;color:var(--txt3);display:flex;align-items:center;gap:.3rem}

/* ─ BUTTONS ─────────────────────────────────────────────── */
.btn{display:inline-flex;align-items:center;gap:.4rem;padding:.6rem 1.1rem;border-radius:var(--rs);border:2px solid transparent;font-family:var(--font);font-size:.85rem;font-weight:700;cursor:pointer;text-decoration:none;transition:all .18s;white-space:nowrap;-webkit-tap-highlight-color:transparent;touch-action:manipulation;line-height:1.3}
.btn-p{background:var(--pri);color:#fff;border-color:var(--pri)}
.btn-p:hover{background:var(--pri-l);color:#fff;transform:translateY(-1px);box-shadow:0 4px 12px rgba(30,58,95,.35)}
.btn-a{background:var(--acc);color:#fff;border-color:var(--acc)}
.btn-a:hover{background:var(--acc-d);color:#fff;transform:translateY(-1px);box-shadow:0 4px 12px rgba(14,165,233,.4)}
.btn-ok{background:var(--ok);color:#fff;border-color:var(--ok)}
.btn-ok:hover{filter:brightness(1.1);transform:translateY(-1px)}
.btn-err{background:var(--err);color:#fff;border-color:var(--err)}
.btn-o{background:transparent;color:var(--pri);border-color:var(--pri)}
.btn-o:hover{background:var(--pri);color:#fff}
.btn-g{background:rgba(0,0,0,.06);color:var(--txt);border-color:transparent}
.btn-g:hover{background:rgba(0,0,0,.1)}
[data-theme=dark] .btn-g{background:rgba(255,255,255,.08)}
[data-theme=dark] .btn-g:hover{background:rgba(255,255,255,.14)}
.btn-sm{padding:.35rem .8rem;font-size:.78rem;border-radius:6px;border-width:1.5px}
.btn-lg{padding:.8rem 1.65rem;font-size:.95rem;border-radius:var(--r)}
.btn-fw{width:100%;justify-content:center}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none!important;box-shadow:none!important}
[data-theme=dark] .btn-o{color:var(--txt);border-color:var(--bdr2)}
[data-theme=dark] .btn-o:hover{background:var(--bdr);color:var(--txt)}

/* ─ FORMS ───────────────────────────────────────────────── */
.fg{margin-bottom:1rem}
.fl{display:block;font-size:.8rem;font-weight:700;color:var(--txt2);margin-bottom:.3rem}
.fc{width:100%;padding:.6rem .85rem;border:2px solid var(--bdr);border-radius:var(--rs);background:var(--card);color:var(--txt);font-family:var(--font);font-size:.88rem;transition:border-color .2s,box-shadow .2s;outline:none;-webkit-appearance:none}
.fc:focus{border-color:var(--acc);box-shadow:0 0 0 3px rgba(14,165,233,.15)}
.fc.err{border-color:var(--err)}
textarea.fc{resize:vertical;min-height:85px}
select.fc{cursor:pointer;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' viewBox='0 0 10 10'%3E%3Cpath fill='%23718096' d='M5 7L0 2h10z'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right .75rem center;padding-right:2.1rem}
.fh{font-size:.73rem;color:var(--txt3);margin-top:.25rem}
.fe{font-size:.73rem;color:var(--err);margin-top:.25rem}
.fgrid{display:grid;gap:.85rem}
.fgrid.c2{grid-template-columns:1fr 1fr}
.fgrid.c3{grid-template-columns:1fr 1fr 1fr}
/* Checkbox / Toggle */
.toggle-wrap{display:flex;align-items:center;gap:.6rem;cursor:pointer}
.toggle-wrap input{position:absolute;opacity:0;width:0;height:0}
.toggle{width:42px;height:24px;background:var(--bdr2);border-radius:12px;position:relative;transition:background .2s;flex-shrink:0}
.toggle::after{content:'';position:absolute;left:3px;top:3px;width:18px;height:18px;background:#fff;border-radius:50%;transition:transform .2s;box-shadow:0 1px 3px rgba(0,0,0,.2)}
.toggle-wrap input:checked+.toggle{background:var(--acc)}
.toggle-wrap input:checked+.toggle::after{transform:translateX(18px)}
.toggle-lbl{font-size:.85rem;color:var(--txt);user-select:none}

/* ─ BADGES ──────────────────────────────────────────────── */
.badge{display:inline-flex;align-items:center;gap:.2rem;padding:.15rem .55rem;border-radius:20px;font-size:.7rem;font-weight:700;line-height:1.4}
.bg-p{background:rgba(30,58,95,.1);color:var(--pri)}
.bg-a{background:rgba(14,165,233,.12);color:var(--acc)}
.bg-ok{background:rgba(16,185,129,.12);color:#065f46}
.bg-w{background:rgba(245,158,11,.12);color:#92400e}
.bg-e{background:rgba(239,68,68,.1);color:var(--err)}
.bg-pur{background:rgba(139,92,246,.1);color:var(--pur)}
[data-theme=dark] .bg-ok{color:#6ee7b7}
[data-theme=dark] .bg-w{color:var(--warn)}
[data-theme=dark] .bg-p{background:rgba(255,255,255,.1);color:#93c5fd}

/* ─ ALERTS ───────────────────────────────────────────────── */
.alert{display:flex;align-items:flex-start;gap:.7rem;padding:.8rem 1rem;border-radius:var(--rs);font-size:.875rem;font-weight:500;margin-bottom:.85rem;border:1px solid transparent;position:relative;animation:sld .22s ease}
.alert-close{margin-left:auto;background:none;border:none;cursor:pointer;opacity:.55;font-size:1rem;padding:0 .2rem;color:inherit;flex-shrink:0}
.a-ok{background:rgba(16,185,129,.1);border-color:rgba(16,185,129,.25);color:#065f46}
.a-err{background:rgba(239,68,68,.1);border-color:rgba(239,68,68,.25);color:#991b1b}
.a-w{background:rgba(245,158,11,.1);border-color:rgba(245,158,11,.25);color:#92400e}
.a-i{background:rgba(14,165,233,.1);border-color:rgba(14,165,233,.25);color:#0c4a6e}
[data-theme=dark] .a-ok{color:#6ee7b7}[data-theme=dark] .a-err{color:#fca5a5}
[data-theme=dark] .a-w{color:#fcd34d}[data-theme=dark] .a-i{color:#7dd3fc}
@keyframes sld{from{opacity:0;transform:translateY(-6px)}to{opacity:1;transform:none}}

/* ─ MODAL (bottom sheet on mobile) ──────────────────────── */
.modal-bg{position:fixed;inset:0;background:rgba(0,0,0,.6);z-index:9000;display:none;align-items:flex-end;justify-content:center;backdrop-filter:blur(4px)}
.modal-bg.show{display:flex;animation:bgIn .2s ease}
@keyframes bgIn{from{opacity:0}to{opacity:1}}
.modal{background:var(--card);width:100%;max-height:92vh;overflow-y:auto;border-radius:var(--rxl) var(--rxl) 0 0;animation:mUp .28s cubic-bezier(.34,1.56,.64,1)}
@keyframes mUp{from{transform:translateY(100%)}to{transform:none}}
.modal-bar{width:36px;height:4px;background:var(--bdr2);border-radius:2px;margin:.6rem auto 0}
.modal-hd{padding:.75rem 1.1rem;border-bottom:1px solid var(--bdr);display:flex;align-items:center;justify-content:space-between;position:sticky;top:0;background:var(--card);z-index:1}
.modal-title{font-size:.95rem;font-weight:800;color:var(--pri)}
[data-theme=dark] .modal-title{color:var(--txt)}
.modal-x{background:none;border:none;font-size:1.25rem;color:var(--txt3);cursor:pointer;padding:.2rem}
.modal-bd{padding:1.1rem}
.modal-ft{padding:.85rem 1.1rem;border-top:1px solid var(--bdr);display:flex;gap:.65rem}

/* ─ EXAM TOPBAR ──────────────────────────────────────────── */
.exam-bar{position:fixed;top:var(--nh);inset-inline:0;z-index:100;background:var(--pri-d);color:#fff;padding:.5rem 1rem;display:flex;align-items:center;gap:.75rem;box-shadow:0 2px 12px rgba(0,0,0,.3)}
.exam-bar-title{font-size:.8rem;font-weight:700;flex:1;overflow:hidden;white-space:nowrap;text-overflow:ellipsis}
.timer{font-size:1.1rem;font-weight:800;font-family:monospace;color:var(--acc);background:rgba(14,165,233,.15);padding:.25rem .7rem;border-radius:6px;min-width:70px;text-align:center;letter-spacing:.5px;flex-shrink:0}
.timer.yellow{color:var(--warn);background:rgba(245,158,11,.15)}
.timer.red{color:var(--err);background:rgba(239,68,68,.15);animation:blink .65s infinite}
@keyframes blink{0%,100%{opacity:1}50%{opacity:.35}}
.exam-prog{flex:1;height:5px;background:rgba(255,255,255,.15);border-radius:3px;overflow:hidden}
.exam-prog-f{height:100%;background:var(--acc);border-radius:3px;transition:width .4s}
.has-exambar{padding-top:calc(var(--nh) + 50px)}

/* ─ ANSWER CHOICES ──────────────────────────────────────── */
.choices{display:flex;flex-direction:column;gap:.5rem}
.choice{display:flex;align-items:flex-start;gap:.8rem;padding:.8rem .95rem;border:2px solid var(--bdr);border-radius:var(--rs);cursor:pointer;transition:all .18s;background:var(--card);touch-action:manipulation;-webkit-tap-highlight-color:transparent}
.choice:hover{border-color:var(--acc);background:rgba(14,165,233,.04)}
.choice.sel{border-color:var(--acc);background:rgba(14,165,233,.09)}
.choice.correct{border-color:var(--ok);background:rgba(16,185,129,.09)}
.choice.wrong{border-color:var(--err);background:rgba(239,68,68,.08)}
.choice input{position:absolute;opacity:0;width:0}
.cl{width:27px;height:27px;min-width:27px;background:var(--bdr);border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.73rem;font-weight:800;color:var(--txt3);transition:all .18s}
.choice.sel .cl{background:var(--acc);color:#fff}
.choice.correct .cl{background:var(--ok);color:#fff}
.choice.wrong .cl{background:var(--err);color:#fff}
.ct{flex:1;font-size:.88rem;line-height:1.55;color:var(--txt);padding-top:.03rem}

/* ─ Q NAVIGATOR ─────────────────────────────────────────── */
.qnav{display:grid;grid-template-columns:repeat(5,1fr);gap:.3rem;padding:.85rem}
.qnb{aspect-ratio:1;border:2px solid var(--bdr);background:transparent;border-radius:6px;font-size:.75rem;font-weight:700;cursor:pointer;color:var(--txt3);transition:all .15s;touch-action:manipulation}
.qnb:hover{border-color:var(--acc);color:var(--acc)}
.qnb.done{background:var(--ok);border-color:var(--ok);color:#fff}
.qnb.curr{background:var(--acc);border-color:var(--acc);color:#fff}
.qnb.flag{background:var(--warn);border-color:var(--warn);color:#fff}

/* ─ PROGRESS ────────────────────────────────────────────── */
.prog{height:7px;background:var(--bdr);border-radius:4px;overflow:hidden}
.prog-f{height:100%;background:linear-gradient(90deg,var(--acc),#38bdf8);border-radius:4px;transition:width .6s cubic-bezier(.34,1.56,.64,1)}
.prog-f.green{background:linear-gradient(90deg,var(--ok),#34d399)}
.prog-f.red{background:linear-gradient(90deg,var(--err),#f87171)}

/* ─ SCORE RING ───────────────────────────────────────────── */
.ring{position:relative;width:130px;height:130px;margin:0 auto}
.ring svg{transform:rotate(-90deg)}
.ring-bg{fill:none;stroke:var(--bdr);stroke-width:10}
.ring-f{fill:none;stroke-width:10;stroke-linecap:round;transition:stroke-dashoffset 1.3s cubic-bezier(.34,1.56,.64,1)}
.ring-txt{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center}
.ring-num{font-size:1.55rem;font-weight:900;line-height:1;color:var(--txt)}
.ring-sub{font-size:.68rem;color:var(--txt3)}

/* ─ STAT CARD ───────────────────────────────────────────── */
.stat{background:var(--card);border-radius:var(--r);padding:1rem;border:1px solid var(--bdr);box-shadow:var(--sh);display:flex;align-items:flex-start;gap:.85rem}
.stat-ico{width:44px;height:44px;border-radius:11px;flex-shrink:0;display:flex;align-items:center;justify-content:center;font-size:1.15rem}
.stat-v{font-size:1.65rem;font-weight:900;color:var(--pri);line-height:1}
[data-theme=dark] .stat-v{color:var(--txt)}
.stat-l{font-size:.75rem;color:var(--txt3);margin-top:.15rem}
.stat-change{font-size:.7rem;font-weight:700;margin-top:.3rem}
.stat-up{color:var(--ok)}.stat-dn{color:var(--err)}

/* ─ TABLE ───────────────────────────────────────────────── */
.tbl-wrap{overflow-x:auto;border-radius:var(--r);box-shadow:var(--sh)}
table{width:100%;border-collapse:collapse;background:var(--card);font-size:.83rem}
thead th{background:var(--pri);color:#fff;padding:.65rem .9rem;text-align:left;font-size:.75rem;white-space:nowrap}
tbody td{padding:.65rem .9rem;border-bottom:1px solid var(--bdr);vertical-align:middle}
tbody tr:last-child td{border-bottom:none}
tbody tr:hover{background:rgba(14,165,233,.04)}
[data-theme=dark] tbody tr:hover{background:rgba(255,255,255,.03)}

/* ─ TABS ────────────────────────────────────────────────── */
.tabs{display:flex;gap:.15rem;border-bottom:2px solid var(--bdr);overflow-x:auto;-ms-overflow-style:none;scrollbar-width:none}
.tabs::-webkit-scrollbar{display:none}
.tab{padding:.6rem .9rem;background:none;border:none;border-bottom:3px solid transparent;font-family:var(--font);font-size:.83rem;font-weight:700;color:var(--txt3);cursor:pointer;margin-bottom:-2px;white-space:nowrap;transition:all .18s}
.tab:hover{color:var(--txt)}
.tab.on{color:var(--pri);border-bottom-color:var(--acc)}
[data-theme=dark] .tab.on{color:var(--acc)}
.tab-pane{display:none}.tab-pane.on{display:block}

/* ─ DROPZONE ────────────────────────────────────────────── */
.dz{border:2px dashed var(--bdr2);border-radius:var(--r);padding:1.75rem 1rem;text-align:center;cursor:pointer;background:var(--bg);transition:all .2s}
.dz:hover,.dz.over{border-color:var(--acc);background:rgba(14,165,233,.04)}
.dz-ico{font-size:2.2rem;margin-bottom:.6rem;color:var(--txt3)}
.dz p{font-size:.83rem;color:var(--txt3);line-height:1.6}

/* ─ QUESTION BUILDER ────────────────────────────────────── */
.qb{background:var(--card);border:2px solid var(--bdr);border-radius:var(--r);margin-bottom:.7rem;overflow:hidden;transition:border-color .18s}
.qb.active{border-color:var(--acc)}
.qb-hd{display:flex;align-items:center;gap:.6rem;padding:.7rem .9rem;background:rgba(0,0,0,.02);cursor:pointer;user-select:none}
[data-theme=dark] .qb-hd{background:rgba(255,255,255,.03)}
.qb-num{width:24px;height:24px;background:var(--pri);color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.7rem;font-weight:800;flex-shrink:0}
.qb-bd{padding:.9rem}
.ans-row{display:flex;align-items:center;gap:.5rem;padding:.45rem .7rem;border:2px solid var(--bdr);border-radius:var(--rs);margin-bottom:.3rem;background:var(--bg);transition:border-color .18s}
.ans-row.ok{border-color:var(--ok);background:rgba(16,185,129,.06)}
.ans-row input[type=text]{flex:1;border:none;background:transparent;font-family:var(--font);font-size:.85rem;color:var(--txt);outline:none;min-width:0}
.ans-l{width:22px;height:22px;background:var(--bdr);border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.68rem;font-weight:800;color:var(--txt3);flex-shrink:0;transition:all .18s}
.ans-row.ok .ans-l{background:var(--ok);color:#fff}

/* ─ PAGINATION ───────────────────────────────────────────── */
.pag{display:flex;justify-content:center;flex-wrap:wrap;gap:.35rem;margin-top:1.5rem}
.pgb{width:34px;height:34px;display:flex;align-items:center;justify-content:center;border:1px solid var(--bdr);border-radius:var(--rs);font-size:.8rem;font-weight:700;color:var(--txt2);text-decoration:none;transition:all .15s}
.pgb:hover{border-color:var(--acc);color:var(--acc)}
.pgb.active{background:var(--pri);border-color:var(--pri);color:#fff}

/* ─ TOAST ───────────────────────────────────────────────── */
#toasts{position:fixed;bottom:1rem;left:50%;transform:translateX(-50%);z-index:99999;width:calc(100% - 2rem);max-width:400px;display:flex;flex-direction:column;gap:.4rem;pointer-events:none}
.toast{display:flex;align-items:center;gap:.6rem;padding:.7rem .9rem;border-radius:10px;font-size:.85rem;font-weight:600;box-shadow:0 6px 24px rgba(0,0,0,.3);pointer-events:all;animation:tIn .25s cubic-bezier(.34,1.56,.64,1)}
.toast-ok{background:#065f46;color:#6ee7b7;border:1px solid rgba(110,231,183,.2)}
.toast-err{background:#7f1d1d;color:#fca5a5;border:1px solid rgba(252,165,165,.2)}
.toast-i{background:#0c4a6e;color:#7dd3fc;border:1px solid rgba(125,211,252,.2)}
@keyframes tIn{from{opacity:0;transform:translateY(16px) scale(.95)}to{opacity:1;transform:none}}

/* ─ FOOTER ──────────────────────────────────────────────── */
footer{background:var(--pri-d);color:rgba(255,255,255,.7);padding:2.25rem 0 1.25rem;margin-top:2.5rem}
.ft-brand{font-size:1rem;font-weight:900;color:#fff;margin-bottom:.4rem;display:flex;align-items:center;gap:.45rem}
.ft-desc{font-size:.78rem;line-height:1.65;opacity:.7}
.ft-grid{display:grid;grid-template-columns:1fr;gap:1.75rem;margin-bottom:1.75rem}
.ft-col h4{color:#fff;font-size:.8rem;margin-bottom:.65rem}
.ft-col ul{list-style:none;display:flex;flex-direction:column;gap:.35rem}
.ft-col a{font-size:.78rem;color:rgba(255,255,255,.55);transition:color .15s}
.ft-col a:hover{color:var(--acc)}
.ft-bot{border-top:1px solid rgba(255,255,255,.1);padding-top:1.1rem;text-align:center;font-size:.73rem;opacity:.45}

/* ─ UTILITIES ───────────────────────────────────────────── */
.g1{gap:.5rem}.g2{gap:.85rem}.g3{gap:1.25rem}
.mt1{margin-top:.5rem}.mt2{margin-top:1rem}.mt3{margin-top:1.5rem}.mt4{margin-top:2rem}
.mb1{margin-bottom:.5rem}.mb2{margin-bottom:1rem}.mb3{margin-bottom:1.5rem}
.p0{padding:0!important}.tc{text-align:center}.tr{text-align:right}
.tm{color:var(--txt3)}.tsm{font-size:.8rem}.txs{font-size:.72rem}
.f7{font-weight:700}.f8{font-weight:800}.f9{font-weight:900}
.hidden{display:none!important}.flex{display:flex}.fc-row{display:flex;align-items:center}.fcb{display:flex;align-items:center;justify-content:space-between}.fcc{display:flex;align-items:center;justify-content:center}.fw{flex-wrap:wrap}
.clp{color:var(--pri)}.cla{color:var(--acc)}.clok{color:var(--ok)}.cle{color:var(--err)}.clw{color:var(--warn)}
.trunc{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.divider{height:1px;background:var(--bdr);margin:1rem 0}

/* ─ RESPONSIVE 480px ────────────────────────────────────── */
@media(min-width:480px){
  .nav-sub{display:block}
  .hero-stats{grid-template-columns:repeat(4,1fr)}
  .subj-grid{grid-template-columns:repeat(3,1fr)}
  .exam-grid{grid-template-columns:repeat(2,1fr)}
  .qnav{grid-template-columns:repeat(6,1fr)}
  .fgrid.c2{grid-template-columns:repeat(2,1fr)}
}
/* ─ RESPONSIVE 768px ────────────────────────────────────── */
@media(min-width:768px){
  :root{--nh:64px}
  .nav-burger{display:none}
  .drawer-overlay,.drawer{display:none!important}
  .nav{padding:0 1.5rem;gap:0}
  .nav-gap{min-width:1.5rem}
  .nav-desktop{display:flex;align-items:center;gap:.1rem}
  .nd-item{display:flex;align-items:center;gap:.35rem;padding:.4rem .7rem;border-radius:7px;color:rgba(255,255,255,.82);font-size:.82rem;font-weight:600;transition:all .15s;text-decoration:none;white-space:nowrap}
  .nd-item:hover,.nd-item.on{background:rgba(255,255,255,.12);color:#fff}
  .nd-item i{font-size:.8rem;opacity:.75}
  .nd-item.on i{opacity:1}
  .subj-grid{grid-template-columns:repeat(4,1fr);gap:.85rem}
  .exam-grid{grid-template-columns:repeat(2,1fr)}
  .ph h1{font-size:1.8rem}
  .ft-grid{grid-template-columns:2fr 1fr 1fr 1fr}
  .modal{max-width:500px;border-radius:var(--rxl);margin:auto}
  @keyframes mUp{from{opacity:0;transform:scale(.95)}to{opacity:1;transform:none}}
  .modal-bar{display:none}
  .fgrid.c2{grid-template-columns:repeat(2,1fr)}
}
/* ─ RESPONSIVE 1024px ───────────────────────────────────── */
@media(min-width:1024px){
  .hero{padding:4rem 0 5.5rem}
  .subj-grid{grid-template-columns:repeat(4,1fr);gap:1rem}
  .exam-grid{grid-template-columns:repeat(3,1fr)}
  .ph h1{font-size:2rem}
  .sec{padding:2.5rem 0}
  .fgrid.c3{grid-template-columns:repeat(3,1fr)}
  .qnav{grid-template-columns:repeat(8,1fr)}
}

/* Desktop nav hidden */
.nav-desktop{display:none}