/* ============ DEDU · ĐỀ THI TRẮC NGHIỆM – giao diện theo hệ sinh thái DEDU ============ */
:root{
  --navy:#0b1224; --ink:#1e293b; --ink2:#334155; --mute:#64748b; --mute2:#94a3b8;
  --line:#e6eaf2; --line2:#eef1f7; --bg:#f5f7fb; --card:#fff;
  --pri:#3b5bfd; --pri2:#6a4ce8; --grad:linear-gradient(90deg,#3366ff 0%,#6a4ce8 100%);
  --pri-2:#eaf0ff; --lav:#efe9ff; --lav-ink:#7c3aed;
  --ok:#16a34a; --ok-2:#e8f7ee; --bad:#dc2626; --bad-2:#fdecec; --warn:#d97706; --warn-2:#fff4e0; --info-bg:#eaf0ff;
  --r:16px; --r-sm:10px; --sh:0 1px 2px rgba(15,23,42,.04),0 4px 16px rgba(15,23,42,.05);
  --sat:env(safe-area-inset-top,0px); --sab:env(safe-area-inset-bottom,0px);
  --font:"Be Vietnam Pro",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;height:100%}
body{font-family:var(--font);color:var(--ink);background:var(--bg);font-size:14.5px;line-height:1.5;-webkit-font-smoothing:antialiased}
h1,h2,h3,h4{margin:0;letter-spacing:-.01em;text-wrap:balance}
a{color:var(--pri);text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
svg.i{width:20px;height:20px;flex:none;stroke:currentColor;fill:none;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-thumb{background:#c9cfdb;border-radius:10px;border:2px solid transparent;background-clip:padding-box}
.c-blue{color:#3b82f6}.c-teal{color:#14b8a6}.c-orange{color:#f97316}.c-violet{color:#8b5cf6}.c-indigo{color:#6366f1}.c-red{color:#ef4444}.c-pink{color:#ec4899}.c-green{color:#22c55e}

/* ---------- Khung ---------- */
.shell{display:grid;grid-template-columns:272px minmax(0,1fr);min-height:100vh}
.sidebar{background:#fff;border-right:1px solid var(--line);display:flex;flex-direction:column;position:sticky;top:0;height:100vh}
.sb-logo{display:flex;align-items:center;gap:12px;padding:20px 22px 18px;border-bottom:1px solid var(--line2)}
.sb-logo .av-img{width:48px;height:48px;border-radius:13px;display:block;flex:none;box-shadow:0 6px 18px rgba(22,163,74,.35)}
.sb-logo b{font-weight:800;font-size:22px;letter-spacing:.02em;background:linear-gradient(90deg,#16a34a,#0ea5a4);-webkit-background-clip:text;background-clip:text;color:transparent;display:block;line-height:1.15}
.sb-logo small{display:block;font-size:10.5px;color:var(--mute2);font-weight:700;letter-spacing:.03em}
.sb-nav{flex:1;overflow:auto;padding:6px 14px}
.sb-sec{font-size:11.5px;font-weight:700;color:var(--mute2);letter-spacing:.08em;text-transform:uppercase;margin:18px 12px 6px}
.sb-item{display:flex;align-items:center;gap:12px;padding:11px 13px;border-radius:14px;font-size:14.5px;font-weight:600;color:#3b4456;white-space:nowrap;transition:background .15s}
.sb-item:hover{background:#f6f4ff}
.sb-item.active{background:var(--lav);color:var(--lav-ink);font-weight:700;box-shadow:inset 0 0 0 1px #e4dafd}
.sb-item.active .ic{color:var(--lav-ink)}
.sb-item .ic{display:grid}.sb-item .ic svg{width:21px;height:21px}
.sb-help{margin:10px 14px 16px;background:linear-gradient(180deg,#eef4ff,#f3f0ff);border:1px solid #dfe6ff;border-radius:16px;padding:14px;text-align:center}
.sb-help b{display:block;color:#1e3a8a;font-size:13.5px}
.sb-help .links{font-size:12px;color:#4f6bd8;margin:2px 0 10px}
.sb-help button{width:100%;border:1px solid #dbe3f5;background:#fff;border-radius:12px;padding:9px;font-weight:700;color:#2546c7;cursor:pointer;box-shadow:0 4px 12px rgba(37,70,199,.1)}
.main{display:flex;flex-direction:column;min-width:0}
.topbar{min-height:68px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;gap:14px;padding:10px 24px;position:sticky;top:0;z-index:20}
.topbar .grow{flex:1;min-width:0}
.topbar h1{font-size:20px;font-weight:800;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.topbar .crumb{font-size:11.5px;color:var(--mute2);font-weight:600;letter-spacing:.02em}
.tb-logo{display:none}
.top-actions{display:flex;gap:8px;flex-wrap:wrap;justify-content:flex-end}
.content{flex:1;padding:22px 24px 48px;min-width:0}
.wrap{max-width:1320px;margin:0 auto}
.bottomnav{display:none}

/* ---------- Thành phần ---------- */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--sh);padding:18px;margin-bottom:16px}
.card h2{font-size:16px;font-weight:800;margin:0 0 12px}
.card h3{font-size:14.5px;font-weight:700;margin:14px 0 8px}
.grid{display:grid;gap:16px}
.grid>*{min-width:0}
.card{min-width:0}
.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))}
.split-260{grid-template-columns:270px minmax(0,1fr)}.split-320{grid-template-columns:330px minmax(0,1fr)}
.row{display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.row.end{justify-content:flex-end}
.spacer{flex:1}
.muted{color:var(--mute)}.small{font-size:12.5px}
.stat{padding:16px 18px;display:flex;flex-direction:column;justify-content:center}
.stat .num{font-size:25px;font-weight:800;line-height:1.15;letter-spacing:-.02em}
.stat .lbl{color:var(--mute);font-size:12.5px;margin-top:2px}
.grid.g4>.stat:nth-child(1){border-top:3px solid #3b82f6}.grid.g4>.stat:nth-child(2){border-top:3px solid #8b5cf6}
.grid.g4>.stat:nth-child(3){border-top:3px solid #14b8a6}.grid.g4>.stat:nth-child(4){border-top:3px solid #f97316}
button,.btn{display:inline-flex;align-items:center;justify-content:center;gap:7px;border:1px solid var(--line);background:#fff;padding:9px 15px;border-radius:12px;font-weight:600;font-size:13.5px;cursor:pointer;white-space:nowrap;transition:.15s;color:var(--ink2);text-decoration:none}
button:hover,.btn:hover{background:#f7f9fc;border-color:#d6dcea}
button:disabled{opacity:.5;cursor:not-allowed}
.btn-pri,a.btn-pri{background:var(--grad);border-color:transparent;color:#fff;box-shadow:0 6px 16px rgba(80,80,240,.25)}
.btn-pri:hover{filter:brightness(1.06);background:var(--grad);border-color:transparent}
.btn-ok{background:var(--ok);border-color:var(--ok);color:#fff}
.btn-soft{background:var(--info-bg);border-color:#dbe4ff;color:#2f4fe0}
.btn-bad{color:var(--bad);border-color:#f6d4d4}.btn-bad:hover{background:var(--bad-2)}
.btn-sm{padding:6px 10px;font-size:12.5px;border-radius:10px}
.btn-icon{padding:7px 10px;border-radius:10px}
input,select,textarea{border:1.5px solid var(--line);border-radius:12px;padding:9px 12px;background:#fff;color:var(--ink);min-width:0;outline:none;transition:.15s;font-size:14px}
input:focus,select:focus,textarea:focus{border-color:#8ea4ff;box-shadow:0 0 0 4px rgba(59,91,253,.1)}
input[type=checkbox],input[type=radio]{width:17px;height:17px;accent-color:var(--pri);padding:0}
input[type=range]{accent-color:var(--pri);padding:0;border:0}
textarea{width:100%;resize:vertical}
label.f{display:flex;flex-direction:column;gap:5px;font-size:12.5px;font-weight:600;color:var(--mute)}
label.f>input,label.f>select,label.f>textarea{color:var(--ink);font-weight:400}
label.chk{display:inline-flex;gap:7px;align-items:center;cursor:pointer;font-size:13.5px}
table.t{width:100%;border-collapse:separate;border-spacing:0;font-size:13.5px;background:#fff}
table.t th{text-align:left;font-size:11.5px;font-weight:700;color:var(--mute);text-transform:uppercase;letter-spacing:.04em;padding:10px 12px;border-bottom:1px solid var(--line);background:#fafbfe;position:sticky;top:0;z-index:1}
table.t td{padding:10px 12px;border-bottom:1px solid var(--line2);vertical-align:middle}
table.t tr:hover td{background:#fafbff}
.tbl-wrap{overflow:auto;max-height:68vh;border:1px solid var(--line);border-radius:14px;-webkit-overflow-scrolling:touch}
.badge{display:inline-flex;align-items:center;gap:4px;padding:3px 9px;border-radius:99px;font-size:11.5px;font-weight:700;background:#eef1f6;color:#475569;white-space:nowrap}
.b-mc{background:var(--info-bg);color:#2f4fe0}.b-tf{background:#f3edff;color:#6d28d9}.b-short{background:var(--ok-2);color:#15803d}
.b-ok{background:var(--ok-2);color:#15803d}.b-warn{background:var(--warn-2);color:#c2410c}.b-bad{background:var(--bad-2);color:var(--bad)}
.q-content{white-space:pre-wrap;line-height:1.55}
.q-code{font-family:Consolas,"Courier New",monospace;background:#f3f5f9;border:1px solid var(--line2);border-radius:10px;padding:8px 10px;display:block;white-space:pre;overflow:auto;font-size:13px;margin:4px 0}
.q-opts{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:3px 16px;margin-top:6px}
.q-opts .correct{color:var(--ok);font-weight:700}
.q-img{max-width:min(280px,100%);max-height:180px;display:block;margin:6px 0;border:1px solid var(--line);border-radius:10px}
.empty{text-align:center;padding:40px 16px;color:var(--mute)}
.tabs{display:flex;gap:4px;background:#eef1f7;padding:4px;border-radius:14px;overflow-x:auto;scrollbar-width:none;margin-bottom:14px;width:fit-content;max-width:100%}
.tabs::-webkit-scrollbar{display:none}
.tabs button{border:0;background:none;padding:8px 14px;border-radius:11px;font-weight:600;font-size:13.5px;color:var(--mute);box-shadow:none}
.tabs button.active{background:#fff;color:var(--ink);box-shadow:0 1px 3px rgba(15,23,42,.1)}
.note{background:var(--info-bg);border:1px solid #dbe4ff;color:#2a44b8;border-radius:12px;padding:10px 14px;font-size:13px}
/* modal */
.modal-back{position:fixed;inset:0;background:rgba(11,18,36,.45);backdrop-filter:blur(3px);z-index:50;display:flex;align-items:center;justify-content:center;padding:16px;animation:fade .15s}
@keyframes fade{from{opacity:0}}
.modal{background:#fff;border-radius:20px;width:min(600px,100%);box-shadow:0 30px 80px rgba(11,18,36,.3);display:flex;flex-direction:column;max-height:94vh;animation:pop .2s cubic-bezier(.2,.9,.3,1.2)}
@keyframes pop{from{transform:scale(.95);opacity:0}}
.modal.wide{width:min(1060px,100%)}.modal.xwide{width:min(1400px,100%)}
.modal-h{padding:16px 20px 10px;display:flex;align-items:center;gap:10px}
.modal-h h3{margin:0;font-size:18px;font-weight:800;flex:1;min-width:0}
.modal-h [data-x]{border-radius:10px;padding:6px 10px}
.modal-b{padding:6px 20px 12px;overflow:auto}
.modal-f{padding:12px 20px 18px;display:flex;gap:10px;justify-content:flex-end;flex-wrap:wrap;align-items:center}
/* toast */
.toasts{position:fixed;right:18px;bottom:18px;z-index:200;display:flex;flex-direction:column;align-items:flex-end;gap:8px;pointer-events:none;max-width:min(380px,calc(100vw - 28px))}
.toast{pointer-events:auto;background:#fff;border:1px solid var(--line);border-left:4px solid var(--pri);border-radius:14px;padding:10px 14px;box-shadow:0 6px 18px rgba(15,23,42,.12);font-size:13.5px;font-weight:600;color:var(--ink);animation:tin .3s cubic-bezier(.2,.9,.3,1.2)}
.toast.ok{border-left-color:var(--ok)}.toast.bad{border-left-color:var(--bad)}.toast.warn{border-left-color:var(--warn)}
@keyframes tin{from{transform:translateY(10px);opacity:0}}
.dropzone{border:2px dashed #c9d3ea;border-radius:16px;padding:28px;text-align:center;color:var(--mute);background:#fafbff;cursor:pointer;transition:.15s}
.dropzone:hover,.dropzone.over{border-color:var(--pri);background:var(--info-bg)}
.dropzone .dz-ic{width:46px;height:46px;border-radius:14px;background:var(--grad);color:#fff;display:inline-grid;place-items:center;margin-bottom:8px;box-shadow:0 8px 20px rgba(80,80,240,.3)}
.progress{height:9px;background:#e9edf5;border-radius:99px;overflow:hidden}
.progress>div{height:100%;background:var(--grad);width:0;transition:width .25s}
.ans-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(92px,1fr));gap:5px}
.ans-grid.tf{grid-template-columns:repeat(auto-fill,minmax(220px,1fr))}
.ans-grid.sh{grid-template-columns:repeat(auto-fill,minmax(130px,1fr))}
.ans-cell{display:flex;gap:4px;align-items:center;border:1px solid var(--line);border-radius:10px;padding:3px 5px;font-size:12.5px;background:#fff}
.ans-cell b{width:22px;text-align:right;flex:none}
.ans-cell input,.ans-cell select{width:100%;padding:3px 4px;font-size:13px;border-radius:7px}
.ans-cell.right{background:var(--ok-2);border-color:#b6e3cf}
.ans-cell.wrong{background:var(--bad-2);border-color:#f2c0c5}
.ans-cell.blank{background:#fff8e6}
.review{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:18px}
.kv{display:grid;grid-template-columns:120px 1fr;gap:4px 10px}
.pill-list{display:flex;gap:8px;flex-wrap:wrap}
.help h3{margin-top:20px}
.help code{background:#f3f5f9;padding:1px 6px;border-radius:6px}
.help pre{background:#f3f5f9;padding:12px;border-radius:12px;overflow:auto;font-size:13px}
.sheet-preview{background:#e9edf5;padding:16px;border-radius:16px;overflow:auto}
.sheet-preview svg{background:#fff;display:block;margin:0 auto;box-shadow:0 8px 30px rgba(15,23,42,.18);width:100%;max-width:820px;height:auto;border-radius:4px}
#clsList .btn{width:100%;margin-bottom:6px;justify-content:space-between}
.mob-only{display:none!important}
/* Quét phiếu bằng camera */
.scan-wrap{display:flex;justify-content:center;background:#0b1224;border-radius:14px;padding:6px}
.scan-box{position:relative;display:inline-block;max-width:100%}
.scan-box video{display:block;max-width:100%;max-height:60vh;border-radius:10px}
.scan-ov{position:absolute;inset:0;width:100%;height:100%;pointer-events:none}
.scan-hint{position:absolute;left:8px;right:8px;bottom:8px;text-align:center;color:#fff;font-size:12.5px;font-weight:600;background:rgba(11,18,36,.55);border-radius:10px;padding:6px}
.scan-last.ok{border-color:#b6e3cf;background:var(--ok-2)}.scan-last.warn{border-color:#fbe2b8;background:var(--warn-2)}
@media (max-width:760px){ .modal.scan-modal{max-height:100vh;height:100vh;border-radius:0} .scan-box video{max-height:58vh} }
/* Trạng thái Google Drive */
.drive-pill{margin-top:8px;font-size:11.5px;font-weight:700;padding:6px 10px;border-radius:99px;cursor:pointer;background:#eef6ff;color:#1d4ed8;border:1px solid #d6e6ff;line-height:1.3}
.drive-pill.sync{background:#f3edff;color:#6d28d9;border-color:#e4dafd}
.drive-pill.warn{background:var(--warn-2);color:#8a4b06;border-color:#fbe2b8}
.drive-pill.ok{background:var(--ok-2);color:#15803d;border-color:#c9ecd6}
.drive-dot{display:none!important;width:40px;height:40px;padding:0;border-radius:12px;font-size:18px;background:var(--ok-2);border-color:#c9ecd6;color:#15803d}
.drive-dot.warn{background:var(--warn-2);border-color:#fbe2b8;color:#8a4b06}.drive-dot.sync{background:#f3edff;color:#6d28d9}
.drive-card{border-color:#d6e6ff;background:linear-gradient(180deg,#f5f9ff,#fff)}
/* Bảng chọn “Thêm” trên điện thoại */
.more-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.more-grid a{display:flex;flex-direction:column;align-items:center;gap:8px;padding:16px 6px;border:1px solid var(--line);border-radius:16px;color:var(--ink2);font-weight:600;font-size:13px;text-align:center;background:#fff}
.more-grid a .ic{width:44px;height:44px;border-radius:14px;display:grid;place-items:center;background:#f4f6fb}
.more-grid a.active{border-color:#e4dafd;background:var(--lav);color:var(--lav-ink)}

@media (max-width:1180px){ .g4{grid-template-columns:repeat(2,minmax(0,1fr))} }
@media (max-width:980px){
  .shell{grid-template-columns:84px minmax(0,1fr)}
  .sb-logo{justify-content:center;padding:16px 8px}
  .sb-logo div,.sb-sec,.sb-help,.sb-item span{display:none}
  .sb-item{justify-content:center;padding:13px}
  .g3{grid-template-columns:1fr}
  .split-260,.split-320{grid-template-columns:1fr}
  .review{grid-template-columns:1fr}
}

/* ================= ĐIỆN THOẠI ================= */
@media (max-width:760px){
  body{font-size:clamp(13.5px,3.7vw,15px)}
  .shell{display:block}
  .sidebar{display:none}
  .topbar{min-height:0;padding:calc(10px + var(--sat)) 14px 10px;gap:10px;flex-wrap:wrap}
  .tb-logo{display:block;width:36px;height:36px;border-radius:10px;box-shadow:0 4px 12px rgba(22,163,74,.3)}
  .topbar h1{font-size:clamp(17px,5vw,20px)}
  .topbar .crumb{display:none}
  .top-actions{width:100%;flex-wrap:nowrap;overflow-x:auto;justify-content:flex-start;scrollbar-width:none;margin:0 -2px;padding:2px}
  .top-actions:empty{display:none}
  .top-actions::-webkit-scrollbar{display:none}
  .top-actions>*{flex:none}
  .content{padding:14px 12px calc(92px + var(--sab));overflow-x:hidden}
  .card{padding:14px;border-radius:14px;margin-bottom:12px}
  .grid{gap:12px}
  .g2,.g3{grid-template-columns:1fr}
  .g4{grid-template-columns:1fr 1fr;gap:10px}
  .stat{padding:12px 14px}.stat .num{font-size:20px}
  input,select,textarea{font-size:16px}  /* tránh iOS tự phóng to khi gõ */
  button,.btn{min-height:40px}
  .btn-sm{min-height:34px}
  .tabs{width:100%}.tabs button{flex:1}
  .q-opts{grid-template-columns:1fr}
  .tbl-wrap{max-height:none}
  .tbl-wrap table.t{min-width:560px}
  .card>table.t{display:block;overflow-x:auto}
  table.t td,table.t th{white-space:nowrap}
  .ans-grid{grid-template-columns:repeat(4,minmax(0,1fr))}
  .ans-grid.tf{grid-template-columns:1fr}
  .ans-grid.sh{grid-template-columns:1fr 1fr}
  .mob-only{display:inline-flex!important}
  .drive-dot.on{display:inline-flex!important}
  .pc-only{display:none!important}
  #clsList{display:flex;gap:8px;overflow-x:auto;scrollbar-width:none;padding-bottom:2px}
  #clsList::-webkit-scrollbar{display:none}
  #clsList .btn{width:auto;flex:0 0 auto;margin:0;gap:10px}
  #clsList .empty{padding:8px}
  .dropzone{padding:20px 14px}
  .sheet-preview{padding:8px}
  /* thanh điều hướng dưới */
  .bottomnav{display:grid;grid-template-columns:repeat(5,1fr);position:fixed;left:0;right:0;bottom:0;background:rgba(255,255,255,.96);backdrop-filter:blur(12px);border-top:1px solid var(--line);padding:6px 6px calc(6px + var(--sab));z-index:40}
  .bottomnav button{border:0;background:none;display:flex;flex-direction:column;align-items:center;gap:3px;font-size:clamp(10px,2.8vw,11.5px);font-weight:600;color:var(--mute);padding:5px 2px;border-radius:12px;min-height:50px;box-shadow:none}
  .bottomnav button i{display:grid}
  .bottomnav button svg{width:23px;height:23px}
  .bottomnav button.active{color:var(--lav-ink)}
  .bottomnav button.active svg{background:var(--lav);border-radius:10px;padding:3px;width:36px;height:29px}
  .bottomnav .bn-main i{width:46px;height:46px;margin-top:-22px;border-radius:16px;background:var(--grad);color:#fff;place-items:center;box-shadow:0 8px 20px rgba(80,80,240,.4);border:3px solid #fff}
  .bottomnav .bn-main svg,.bottomnav .bn-main.active svg{width:22px;height:22px;background:none;padding:0}
  /* hộp thoại dạng tấm trượt từ dưới lên */
  .modal-back{align-items:flex-end;padding:0}
  .modal,.modal.wide,.modal.xwide{width:100%;max-width:none;border-radius:22px 22px 0 0;max-height:94vh;animation:sheet .25s cubic-bezier(.2,.9,.3,1)}
  @keyframes sheet{from{transform:translateY(40px);opacity:0}}
  .modal-h{padding:14px 16px 8px}
  .modal-h:before{content:"";position:absolute;left:50%;top:6px;width:40px;height:4px;border-radius:9px;background:#d6dbe6;transform:translateX(-50%)}
  .modal{position:relative}
  .modal-b{padding:6px 16px 10px}
  .modal-f{padding:10px 16px calc(14px + var(--sab));flex-wrap:nowrap}
  .modal-f>button{flex:1;min-width:0}
  .modal-f>span{display:none}
  .toasts{right:10px;left:10px;top:calc(8px + var(--sat));bottom:auto;align-items:center;max-width:none}
}
@media (max-width:360px){ .g4{grid-template-columns:1fr} .bottomnav button span{font-size:9.5px} }

@media print{
  body *{visibility:hidden}
  #printArea,#printArea *{visibility:visible}
  #printArea{position:absolute;left:0;top:0}
}