/* ============================================================
   trinhchieu.css - giao diện trình chiếu (GV) + trả lời (HS). Độc lập.
   ============================================================ */
*{box-sizing:border-box}
body{margin:0;font-family:'Segoe UI',system-ui,Arial,sans-serif}
.tc-body{background:linear-gradient(135deg,#0f2027,#203a43,#2c5364);color:#fff;min-height:100vh}
.hs-body{background:linear-gradient(135deg,#6a11cb,#2575fc);min-height:100vh}
.tc-btn{border:none;border-radius:12px;cursor:pointer;font-weight:700;font-size:16px;padding:12px 18px;transition:.15s;color:#fff;background:#3a6df0}
.tc-btn:hover{filter:brightness(1.08)}
.tc-btn-main{background:linear-gradient(135deg,#11998e,#38ef7d);color:#063}
.tc-btn-sm{font-size:14px;padding:9px 13px}
.tc-btn-ghost{background:rgba(255,255,255,.16)}
.tc-btn-nav{background:rgba(255,255,255,.18)}
.tc-btn-end{background:#e74c3c}
.tc-btn-update{background:linear-gradient(135deg,#f7971e,#ffd200);color:#5a3e00;width:100%}
.tc-label{display:block;font-size:14px;opacity:.85;margin:14px 0 6px;font-weight:600}
.tc-msg{margin-top:10px;font-size:14px;min-height:18px}
.tc-msg.ok{color:#7CFFB2}.tc-msg.err{color:#ffb3b3}

/* ---- Màn chọn đề (GV) ---- */
.tc-setup{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:20px}
.tc-setup-card{background:rgba(255,255,255,.08);backdrop-filter:blur(8px);border:1px solid rgba(255,255,255,.15);
               border-radius:22px;padding:34px;max-width:560px;width:100%;box-shadow:0 20px 60px rgba(0,0,0,.35)}
.tc-setup-card h1{margin:0 0 6px;font-size:30px}
.tc-sub{opacity:.85;margin:0 0 8px;line-height:1.5}
.tc-select{width:100%;padding:13px 14px;border-radius:12px;border:none;font-size:16px;margin-bottom:16px}
.tc-back{display:inline-block;margin-top:16px;color:#cfe;text-decoration:none}

/* ---- Trình chiếu (GV) ---- */
.tc-live{min-height:100vh;display:flex;flex-direction:column;padding:16px 20px;gap:14px}
.tc-topbar{display:flex;justify-content:space-between;align-items:center;gap:16px;flex-wrap:wrap}
.tc-pin-box{display:flex;align-items:baseline;gap:14px;flex-wrap:wrap}
.tc-pin-label{font-size:14px;opacity:.8}
.tc-pin{font-size:40px;font-weight:900;letter-spacing:6px;color:#ffd200}
.tc-join-link{font-size:14px;opacity:.85}
.tc-timer-box{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.tc-sec{width:90px;padding:10px;border-radius:10px;border:none;font-size:16px;text-align:center}
.tc-clock{font-size:40px;font-weight:900;font-variant-numeric:tabular-nums;min-width:120px;text-align:center;
          background:rgba(0,0,0,.25);border-radius:12px;padding:4px 14px}
.tc-clock-low{color:#ff5252;animation:tcpulse .6s infinite alternate}
@keyframes tcpulse{from{transform:scale(1)}to{transform:scale(1.12)}}

.tc-main{flex:1;display:grid;grid-template-columns:1fr 360px;gap:18px;align-items:start}
.tc-qpanel{background:rgba(255,255,255,.96);color:#1a2533;border-radius:20px;padding:30px 34px;box-shadow:0 12px 40px rgba(0,0,0,.3)}
.tc-qhead{display:flex;align-items:center;gap:12px;margin-bottom:14px}
.tc-qnum{font-size:22px;font-weight:800;color:#2575fc}
.tc-qbadge{font-size:14px;background:#eef0ff;color:#3730a3;padding:4px 12px;border-radius:999px;font-weight:700}
.tc-qlock{font-size:14px;background:#ffe3e3;color:#c0392b;padding:4px 12px;border-radius:999px;font-weight:700}
.tc-doanvan{background:#f3f6ff;border-left:5px solid #2575fc;border-radius:10px;padding:14px 16px;margin-bottom:14px;font-size:21px;line-height:1.7}
.tc-de2{font-size:27px;line-height:1.6;font-weight:600;margin-bottom:20px}
.tc-options{display:flex;flex-direction:column;gap:12px}
.tc-opt{display:flex;align-items:center;gap:14px;background:#f6f8ff;border:2px solid #e6e8f2;border-radius:14px;padding:13px 16px;font-size:23px}
.tc-opt-mini{font-size:19px;padding:8px 12px}
.tc-opt-key{display:inline-flex;align-items:center;justify-content:center;width:44px;height:44px;min-width:44px;border-radius:50%;
            background:linear-gradient(135deg,#2575fc,#6a11cb);color:#fff;font-weight:800;font-size:20px}
.tc-opt-text{flex:1}
.tc-sub{margin-bottom:14px}
.tc-sub-de{font-size:20px;font-weight:600;margin:6px 0}
.tc-chips{display:flex;flex-wrap:wrap;gap:10px}
.tc-chip{background:#eef2ff;border:2px solid #c7d2fe;border-radius:10px;padding:8px 14px;font-size:20px;font-weight:600}
.tc-pairs{display:flex;gap:30px;font-size:20px}.tc-pair-col>div{padding:6px 0}
.tc-hint{font-size:18px;color:#667;font-style:italic}

.tc-side{display:flex;flex-direction:column;gap:14px}
.tc-side-card{background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.16);border-radius:16px;padding:16px}
.tc-answered{font-size:20px;margin-bottom:12px}.tc-answered b{font-size:26px;color:#ffd200}
.tc-auto{margin-top:10px;font-size:13px;opacity:.85}
.tc-stat-title{font-weight:700;margin-bottom:10px}
.tc-stats{display:flex;flex-direction:column;gap:9px;margin-bottom:12px}
.tc-bar-row{display:flex;align-items:center;gap:10px}
.tc-bar-key{width:34px;height:34px;min-width:34px;border-radius:50%;background:rgba(255,255,255,.2);display:flex;align-items:center;justify-content:center;font-weight:800}
.tc-bar-key2{font-size:13px;min-width:70px;max-width:90px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.tc-bar-track{position:relative;flex:1;height:34px;background:rgba(0,0,0,.22);border-radius:8px;overflow:hidden}
.tc-bar-fill{height:100%;background:linear-gradient(90deg,#38ef7d,#11998e);transition:width .4s}
.tc-bar-num{position:absolute;right:10px;top:50%;transform:translateY(-50%);font-size:13px;font-weight:700}
.tc-bar-correct .tc-bar-key{background:#38ef7d;color:#063}
.tc-bar-correct .tc-bar-fill{background:linear-gradient(90deg,#ffd200,#f7971e)}
.tc-bar-tick{color:#7CFFB2;font-weight:900}

.tc-foot{display:flex;align-items:center;justify-content:center;gap:12px;flex-wrap:wrap;padding-top:6px}
.tc-progress{font-size:18px;font-weight:700;opacity:.9}

@media(max-width:900px){
  .tc-main{grid-template-columns:1fr}
  .tc-de2{font-size:22px}.tc-opt{font-size:19px}
  .tc-pin{font-size:32px}.tc-clock{font-size:30px}
}

/* ---- Màn trả lời (HS) ---- */
.hs-join{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:18px}
.hs-join-card{background:#fff;border-radius:22px;padding:28px 24px;max-width:420px;width:100%;box-shadow:0 18px 50px rgba(0,0,0,.3)}
.hs-join-card h1{margin:0 0 6px;font-size:26px;color:#2d3436;text-align:center}
.hs-join-card .tc-label{color:#555}
.hs-input{width:100%;padding:14px;border:2px solid #e0e0e0;border-radius:12px;font-size:17px;margin-bottom:6px}
.hs-join-card .tc-btn-main{width:100%;margin-top:14px}
.hs-play{min-height:100vh;display:flex;flex-direction:column;padding:12px}
.hs-bar{display:flex;justify-content:space-between;align-items:center;color:#fff;padding:6px 6px 12px;font-weight:600}
.hs-status{background:rgba(255,255,255,.2);padding:5px 12px;border-radius:999px;font-size:14px}
.hs-qcard{background:#fff;border-radius:20px;padding:20px 18px;flex:1;box-shadow:0 12px 36px rgba(0,0,0,.25);display:flex;flex-direction:column}
.hs-qnum{font-weight:800;color:#2575fc;font-size:18px;margin-bottom:8px}
.hs-doanvan{background:#f3f6ff;border-left:4px solid #2575fc;border-radius:8px;padding:12px;margin-bottom:12px;font-size:17px;line-height:1.6}
.hs-de{font-size:21px;line-height:1.6;font-weight:600;color:#1a2533;margin-bottom:16px}
.hs-answer{display:flex;flex-direction:column;gap:12px}
.hs-opt{display:flex;align-items:center;gap:14px;background:#f6f8ff;border:2px solid #e6e8f2;border-radius:16px;padding:16px;font-size:19px;cursor:pointer;text-align:left;width:100%}
.hs-opt:active{transform:scale(.99)}
.hs-opt.sel{border-color:#2575fc;background:linear-gradient(135deg,#eef2ff,#e0e7ff);box-shadow:0 6px 18px rgba(37,117,252,.25)}
.hs-opt.sel .tc-opt-key{transform:scale(1.08)}
.hs-ds-row{display:flex;justify-content:space-between;align-items:center;gap:12px;background:#f6f8ff;border:2px solid #e6e8f2;border-radius:14px;padding:12px 14px}
.hs-ds-text{font-size:17px;line-height:1.5}
.hs-ds-pick{display:flex;gap:8px}
.hs-ds-btn{border:2px solid #dcdfee;background:#fff;border-radius:999px;padding:10px 16px;font-weight:700;font-size:15px;cursor:pointer;min-width:64px}
.hs-ds-btn.sel{background:linear-gradient(135deg,#2575fc,#6a11cb);color:#fff;border-color:transparent}
.hs-sub{background:#f9faff;border:1px solid #eef;border-radius:12px;padding:12px;margin-bottom:4px}
.hs-sub-de{font-size:16px;font-weight:600;margin-bottom:8px}
.hs-sub-opts{display:flex;flex-direction:column;gap:8px}
.hs-subopt{text-align:left;border:2px solid #e6e8f2;background:#fff;border-radius:12px;padding:11px 14px;font-size:16px;cursor:pointer}
.hs-subopt.sel{border-color:#2575fc;background:#eef2ff}
.hs-submit{margin-top:18px}
.tc-btn.disabled{opacity:.5;cursor:not-allowed}

/* ---- QR + danh sách tên + lời giải (đợt 11) ---- */
.tc-pin-box{align-items:center}
.tc-qr{width:96px;height:96px;border-radius:12px;background:#fff;padding:6px;box-shadow:0 4px 14px rgba(0,0,0,.3)}
.tc-pin-info{display:flex;flex-direction:column;gap:2px}
.tc-names{display:flex;flex-wrap:wrap;gap:5px;margin:2px 0 8px 44px}
.tc-name{background:rgba(255,255,255,.18);border-radius:999px;padding:2px 9px;font-size:12.5px}
.tc-bar-correct + .tc-names .tc-name{background:rgba(56,239,125,.28)}
.tc-loigiai{margin-top:12px;background:#fff;color:#1a2533;border-radius:12px;padding:14px 16px;font-size:16px;line-height:1.6;max-height:42vh;overflow:auto}
.tc-lg-dap{font-size:17px;margin-bottom:8px;color:#0a7d33}
.tc-lg-body{line-height:1.7}
@media(max-width:900px){ .tc-qr{width:80px;height:80px} .tc-names{margin-left:0} }

/* ===== Đợt 12: DS1, mắt xem tên, chưa trả lời, DoanVan đẹp ===== */
/* GV: Đúng/Sai 1 phát biểu */
.tc-tf{display:flex;gap:12px;margin-top:6px}
.tc-tf-pill{background:#eef0ff;border-radius:10px;padding:8px 18px;font-weight:700;font-size:20px;color:#2575fc}
/* GV: nút con mắt + modal danh sách tên */
.tc-eye{margin-left:8px;border:none;background:rgba(255,255,255,.2);color:#fff;border-radius:8px;padding:5px 9px;font-size:13px;cursor:pointer;white-space:nowrap}
.tc-eye:hover{background:rgba(255,255,255,.34)}
.tc-names-modal{position:fixed;inset:0;background:rgba(0,0,0,.55);display:flex;align-items:center;justify-content:center;z-index:50;padding:16px}
.tc-names-box{background:#fff;color:#1a2533;border-radius:16px;max-width:520px;width:100%;max-height:80vh;overflow:auto;box-shadow:0 20px 60px rgba(0,0,0,.4)}
.tc-names-head{display:flex;justify-content:space-between;align-items:center;padding:16px 18px;border-bottom:1px solid #eee;font-weight:800;font-size:18px;position:sticky;top:0;background:#fff}
.tc-names-close{border:none;background:#f1f1f4;border-radius:8px;width:34px;height:34px;font-size:16px;cursor:pointer}
.tc-names-listbox{padding:16px 18px;display:flex;flex-wrap:wrap;gap:8px}
.tc-names-listbox .tc-name{background:#eef2ff;color:#3730a3;border-radius:999px;padding:6px 14px;font-size:15px}
/* GV: chưa trả lời */
.tc-unanswered{margin-top:10px}
.tc-unans-count{font-size:15px;color:#ffd6d6}
.tc-names-red .tc-name{background:rgba(231,76,60,.3)}
.tc-sub-no{display:inline-flex;align-items:center;justify-content:center;width:26px;height:26px;border-radius:50%;background:#2575fc;color:#fff;font-weight:800;font-size:14px;margin-right:6px}

/* HS: phương án trắc nghiệm gọn */
.hs-opts{display:flex;flex-direction:column;gap:10px}
.hs-key{display:inline-flex;align-items:center;justify-content:center;width:38px;height:38px;min-width:38px;border-radius:50%;background:linear-gradient(135deg,#2575fc,#6a11cb);color:#fff;font-weight:800;font-size:17px}
.hs-otext{flex:1;text-align:left}
/* HS: Đúng/Sai 1 phát biểu */
.hs-tf{display:flex;gap:14px}
.hs-tf-btn{flex:1;border:2px solid #e6e8f2;background:#fff;border-radius:16px;padding:18px;font-size:20px;font-weight:800;cursor:pointer}
.hs-tf-true.sel{background:linear-gradient(135deg,#11998e,#38ef7d);color:#063;border-color:transparent}
.hs-tf-false.sel{background:linear-gradient(135deg,#eb3349,#f45c43);color:#fff;border-color:transparent}
/* HS: thẻ câu con trong đoạn văn (đẹp) */
.hs-subcard{background:#f7f9ff;border:1px solid #e6ebff;border-radius:16px;padding:14px;margin-bottom:14px;box-shadow:0 2px 8px rgba(40,60,160,.06)}
.hs-sub-head{display:flex;align-items:center;gap:8px;font-weight:800;color:#3730a3;font-size:14px;margin-bottom:8px}
.hs-sub-no{display:inline-flex;align-items:center;justify-content:center;width:26px;height:26px;border-radius:50%;background:#2575fc;color:#fff;font-size:13px}
.hs-sub-de{font-size:17px;line-height:1.55;margin-bottom:10px;color:#1a2533}

/* ===== HS: vòng tròn tiến độ + điểm (đợt 13) ===== */
.hs-progress{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:0 4px 10px;flex-wrap:wrap}
.hs-circles{display:flex;flex-wrap:wrap;gap:6px}
.hs-circle{display:inline-flex;align-items:center;justify-content:center;width:30px;height:30px;border-radius:50%;
           font-weight:800;font-size:13px;color:#fff;background:rgba(255,255,255,.35)}
.hs-c-chua{background:rgba(255,255,255,.30);color:#fff}
.hs-c-daTraLoi{background:#4a90ff}
.hs-c-dung{background:#21c87a}
.hs-c-sai{background:#ff5252}
.hs-c-cham{background:#f7971e}
.hs-c-now{box-shadow:0 0 0 3px #fff, 0 0 0 5px rgba(255,255,255,.4);transform:scale(1.08)}
.hs-score{background:rgba(0,0,0,.22);color:#fff;border-radius:999px;padding:6px 14px;font-size:15px;white-space:nowrap}
.hs-score b{color:#ffd200;font-size:17px}

/* ===== Bảng xếp hạng (đợt 14) ===== */
.tc-rank-list{padding:8px 12px 16px}
.tc-rank-tb{width:100%;border-collapse:collapse;font-size:15px}
.tc-rank-tb th,.tc-rank-tb td{padding:9px 10px;text-align:left;border-bottom:1px solid #eee}
.tc-rank-tb th{font-size:13px;color:#667;font-weight:700}
.tc-rank-no{font-weight:800;font-size:16px;width:48px;text-align:center}
.tc-rank-pt{font-weight:800;color:#0a7d33}
.tc-rank-tb tr:nth-child(-n+3) .tc-rank-pt{color:#c47b00}

/* ---- Chọn nguồn đề: tab + file .txt / dán (đợt 8) ---- */
.cd-tabs{display:flex;gap:8px;margin:14px 0 6px;flex-wrap:wrap}
.cd-tab{flex:1;min-width:200px;border:1px solid rgba(255,255,255,.25);background:rgba(255,255,255,.08);
  color:#eaf2ff;border-radius:12px;padding:11px 12px;font-weight:700;font-size:15px;cursor:pointer;transition:.15s}
.cd-tab:hover{background:rgba(255,255,255,.16)}
.cd-tab-on{background:linear-gradient(135deg,#2575fc,#6a11cb);color:#fff;border-color:transparent}
.cd-src{margin-top:4px}
.cd-file{display:block;width:100%;color:#eaf2ff;background:rgba(255,255,255,.10);border:1px dashed rgba(255,255,255,.4);
  border-radius:12px;padding:12px;font-size:15px;cursor:pointer;box-sizing:border-box}
.cd-file::file-selector-button{border:none;border-radius:9px;padding:8px 14px;margin-right:12px;font-weight:700;background:#3a6df0;color:#fff;cursor:pointer}
.cd-raw{width:100%;border-radius:12px;border:none;padding:12px 14px;font-size:14px;font-family:ui-monospace,Consolas,monospace;
  line-height:1.5;resize:vertical;box-sizing:border-box;margin-bottom:6px}
.cd-hint{opacity:.75;font-size:13px;margin:6px 0 0}

/* ---- HS trả lời: Sắp xếp (SapXep) & Xếp cặp (XepCap) (đợt 9) ---- */
.hs-sx-help{font-size:14px;color:#555;margin:4px 0 10px;min-height:20px}
.hs-sx-wrap{display:flex;flex-wrap:wrap;gap:10px}
.hs-sx-chip{position:relative;display:inline-flex;align-items:center;gap:8px;background:#fff;border:2px solid #cfd6e6;
  border-radius:12px;padding:11px 14px;font-size:17px;cursor:pointer;transition:.12s;color:#1b2230}
.hs-sx-chip:hover{border-color:#2575fc}
.hs-sx-chip.sel{border-color:#11998e;background:#ecfdf3}
.hs-sx-badge{min-width:24px;height:24px;display:inline-flex;align-items:center;justify-content:center;border-radius:50%;
  font-size:13px;font-weight:800;color:#fff;background:transparent}
.hs-sx-chip.sel .hs-sx-badge{background:#11998e}
.hs-sx-clear{margin-top:12px;border:none;background:#eef0f6;color:#444;border-radius:10px;padding:8px 14px;font-weight:700;cursor:pointer}
.hs-xc{display:flex;flex-direction:column;gap:10px}
.hs-xc-opts{background:#f4f7ff;border:1px solid #dbe4fb;border-radius:12px;padding:12px 14px;margin-bottom:12px}
.hs-xc-opts-t{font-weight:800;color:#2b3b66;margin-bottom:8px;font-size:14px}
.hs-xc-opt{display:flex;gap:8px;align-items:baseline;padding:5px 0;font-size:17px;color:#1b2230}
.hs-xc-let{font-weight:800;color:#2575fc;min-width:26px;flex:0 0 auto}
.hs-xc-opt-text{flex:1}
.hs-xc-row{display:flex;align-items:center;gap:10px;background:#fff;border:1px solid #e6e8f2;border-radius:12px;padding:10px 12px}
.hs-xc-left{flex:1;font-size:17px;color:#1b2230}
.hs-xc-arrow{color:#9aa3b8;font-weight:800;flex:0 0 auto}
.hs-xc-sel{padding:10px;border-radius:10px;border:1.5px solid #cfd6e6;font-size:15px;background:#fff}
.hs-xc-sel-letter{flex:0 0 auto;width:88px;text-align:center;font-weight:800;font-size:17px}
.hs-xc-sel:focus{outline:none;border-color:#2575fc}
/* GV: lời giải dạng cặp */
.tc-lg-pairs{margin:6px 0 4px;font-size:20px;line-height:1.6}

/* ---- HS: khối Đáp án & Lời giải khi GV bật "Hiện lời giải" (đợt 9) ---- */
.hs-lg{margin-top:16px;border:1px solid #ffe2a8;border-radius:16px;overflow:hidden;
  box-shadow:0 6px 18px rgba(245,158,11,.12);animation:hslgIn .25s ease}
@keyframes hslgIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
.hs-lg-head{background:linear-gradient(90deg,#f59e0b,#f6b73c);color:#fff;font-weight:800;
  padding:11px 16px;font-size:16px;letter-spacing:.2px}
.hs-lg-dap{padding:12px 16px;background:#fffdf7;border-bottom:1px dashed #f0d79a}
.hs-lg-label{font-size:12px;font-weight:800;color:#b4791b;text-transform:uppercase;letter-spacing:.5px;margin-bottom:6px}
.hs-lg-ans{font-size:19px;color:#1b2230;font-weight:700;overflow-wrap:anywhere}
.hs-lg-seq{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.hs-lg-step{display:inline-flex;align-items:center;gap:7px;background:#ecfdf3;border:1px solid #b7ebc6;
  border-radius:10px;padding:6px 11px;max-width:100%}
.hs-lg-no{min-width:22px;height:22px;border-radius:50%;background:#11998e;color:#fff;font-weight:800;
  font-size:12px;display:inline-flex;align-items:center;justify-content:center;flex:0 0 auto}
.hs-lg-tok{font-size:18px;color:#13543f;overflow-wrap:anywhere}
.hs-lg-arrow{color:#9aa3b8;font-weight:800;flex:0 0 auto}
.hs-lg-pairs{display:flex;flex-direction:column;gap:8px}
.hs-lg-pair{display:flex;align-items:center;gap:10px;flex-wrap:wrap;background:#f4f7ff;border:1px solid #dbe4fb;
  border-radius:10px;padding:8px 12px}
.hs-lg-pl{flex:1;min-width:120px;color:#1b2230;font-size:17px;overflow-wrap:anywhere}
.hs-lg-pr{flex:1;min-width:120px;color:#13408a;font-weight:700;font-size:17px;overflow-wrap:anywhere}
.hs-lg-body{padding:13px 16px;background:#fff;color:#26303f;font-size:17px;line-height:1.7;overflow-wrap:anywhere}
/* Công thức dài tự xuống dòng (MathJax 4) hoặc cuộn ngang dự phòng */
.hs-lg mjx-container{max-width:100%}
.hs-lg mjx-container[display="true"]{overflow-x:auto;overflow-y:hidden}