:root{--ink:#1f302d;--muted:#687b74;--green:#15473d;--green-2:#24685a;--green-soft:#e4efea;--gold:#b48a4a;--gold-soft:#fbf3e5;--cream:#f9f8f4;--paper:#fff;--line:#e2e8e2;--warn:#a46827;--warn-bg:#fff6e8;--red:#a3453d;--shadow:0 10px 40px rgba(30,60,47,.045);--radius:18px}
*{box-sizing:border-box}html{font-size:16px}body{margin:0;background:var(--cream);font-family:Inter,"Segoe UI",-apple-system,BlinkMacSystemFont,"Helvetica Neue",Arial,sans-serif;color:var(--ink);line-height:1.52}button,input,textarea,select{font:inherit}button{cursor:pointer}button:disabled{opacity:.45;cursor:not-allowed}a{color:inherit}*:focus-visible{outline:3px solid #93bca8;outline-offset:3px}.shell{max-width:1360px;margin:auto;padding:0 32px}.topbar{height:80px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);background:rgba(255,255,255,.86)}.brand{display:flex;align-items:center;gap:13px;font-weight:800;letter-spacing:-.02em;font-size:19px;cursor:pointer}.brand-logo{width:41px;height:41px;display:grid;place-items:center;border-radius:13px;background:var(--green);color:#fff;font-size:24px;line-height:1}.brand-sub{font-size:11px;letter-spacing:.2em;font-weight:700;color:var(--muted);display:block;margin-top:-2px}.brand-word{display:block}.top-links{display:flex;align-items:center;gap:9px}.nav-btn{background:transparent;border:1px solid transparent;border-radius:10px;padding:10px 13px;color:#596c64;font-weight:700;font-size:13px}.nav-btn.active{background:#eef4ef;color:var(--green)}.nav-btn:hover{background:#f1f4ef}.nav-btn.danger:hover{background:#fff0ed;color:var(--red)}.container{max-width:1260px;margin:0 auto;padding:42px 32px 80px}.eyebrow{font-size:11px;letter-spacing:.17em;text-transform:uppercase;color:var(--green-2);font-weight:800}.hero{display:flex;justify-content:space-between;align-items:flex-end;gap:25px;margin:15px 0 30px}.hero h1{font-family:Georgia,"Times New Roman",serif;font-weight:500;font-size:clamp(36px,4vw,54px);line-height:1.12;letter-spacing:-.045em;margin:10px 0}.hero p{max-width:680px;margin:12px 0 0;color:var(--muted);font-size:15px}.hero-mark{width:160px;height:110px;display:grid;place-items:center;color:#d9c6a3;font-size:95px;line-height:1;opacity:.65}.cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:22px}.exam-card,.panel{background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}.exam-card{padding:28px;position:relative;overflow:hidden}.exam-card:before{content:"";position:absolute;inset:0 0 auto;height:5px;background:var(--green)}.exam-card.advanced:before{background:var(--gold)}.exam-topline{display:flex;align-items:center;justify-content:space-between;gap:12px}.tag{display:inline-block;border-radius:100px;padding:5px 11px;font-size:11px;font-weight:800;color:var(--green);background:#edf4ef}.tag.gold{color:#987338;background:#fbf1df}.tag.gray{color:#58675f;background:#eff2ee}.tag.warn{color:#8d5c21;background:var(--warn-bg)}.question-count{font-family:Georgia,"Times New Roman",serif;font-size:71px;letter-spacing:-.07em;line-height:1.15;margin:14px 0 0}.exam-card h2{font-size:19px;margin:2px 0 4px}.subtle{color:var(--muted)}.small{font-size:13px}.tiny{font-size:11px}.exam-card .line{border-top:1px solid var(--line);margin:20px 0 18px}.facts{display:flex;gap:13px;flex-wrap:wrap;font-size:12px;color:var(--muted);margin-bottom:21px}.fact b{color:var(--ink)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:9px;border-radius:11px;padding:11px 17px;font-size:13px;font-weight:800;border:1px solid transparent;white-space:nowrap;text-decoration:none;transition:background .18s,transform .18s}.btn:hover:not(:disabled){transform:translateY(-1px)}.btn-primary{background:var(--green);color:white}.btn-primary:hover:not(:disabled){background:#0d372f}.btn-outline{border-color:#cad7d0;background:white;color:var(--green)}.btn-quiet{border-color:transparent;color:var(--muted);background:#f2f5f1}.btn-muted{background:#e7eee9;color:var(--green)}.btn-danger{color:var(--red);background:#fff1ed;border-color:#f5d1cc}.btn-sm{font-size:12px;padding:8px 11px;border-radius:9px}.btn-block{width:100%}.card-actions{display:flex;gap:10px}.section-head{display:flex;align-items:center;justify-content:space-between;gap:15px;margin:43px 0 16px}.section-head h2{font-size:21px;margin:0;letter-spacing:-.025em}.note{background:#f0f5ee;border:1px solid #deeadc;color:#476357;padding:16px 18px;border-radius:12px;line-height:1.6;font-size:13px}.attempts{display:grid;grid-template-columns:repeat(auto-fit,minmax(320px,1fr));gap:13px}.attempt-card{padding:20px;display:flex;align-items:center;justify-content:space-between;gap:14px}.attempt-card .title{font-weight:800}.progress-track{height:7px;background:#e9eee9;border-radius:20px;overflow:hidden}.progress-fill{background:var(--green-2);height:100%;border-radius:20px}.exam-layout{display:grid;grid-template-columns:minmax(0,1fr) 318px;gap:25px;align-items:start;padding-top:30px}.exam-context{display:flex;justify-content:space-between;align-items:center;gap:18px;padding-bottom:17px;border-bottom:1px solid var(--line);margin-bottom:21px}.exam-name{font-size:15px;font-weight:800}.exam-id{font-size:12px;color:var(--muted)}.exam-context .progress-track{width:170px;margin-top:8px}.question-panel{padding:31px 35px}.q-meta{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px}.q-number{font-size:12px;color:var(--muted);font-weight:700}.q-text{font-size:clamp(20px,2.3vw,26px);font-weight:700;line-height:1.5;letter-spacing:-.016em;margin:27px 0}.options{display:grid;gap:12px}.option{display:flex;text-align:left;gap:16px;align-items:start;border:1.5px solid #dbe3db;background:white;border-radius:12px;width:100%;padding:17px 18px;line-height:1.6;font-size:15px;transition:border .15s,background .15s}.option:hover{border-color:#8eafa1;background:#fcfefd}.option.chosen{border-color:var(--green);background:#edf5ee}.option-letter{flex:0 0 28px;width:28px;height:28px;display:grid;place-items:center;font-weight:800;border:1px solid #cfdad2;color:#63766b;border-radius:8px;font-size:12px}.option.chosen .option-letter{color:white;background:var(--green);border-color:var(--green)}.text-area{width:100%;border:1.5px solid #dce5dd;border-radius:12px;min-height:235px;padding:16px 18px;resize:vertical;line-height:1.7;color:var(--ink);background:#fff}.answer-help{display:flex;justify-content:space-between;gap:10px;color:var(--muted);font-size:12px;margin-top:12px}.q-footer{display:flex;align-items:center;justify-content:space-between;gap:9px;border-top:1px solid var(--line);margin-top:28px;padding-top:24px}.button-row{display:flex;align-items:center;gap:9px}.palette{padding:20px;position:sticky;top:18px}.palette-head{display:flex;justify-content:space-between;align-items:center;gap:12px}.palette-head h3{margin:0;font-size:15px}.palette-summary{color:var(--muted);font-size:12px;margin:10px 0 18px}.palette-legend{display:flex;flex-wrap:wrap;gap:12px;margin-bottom:22px;color:var(--muted);font-size:11px}.legend-square{display:inline-block;height:9px;width:9px;background:#f0f1eb;border:1px solid #c9d6ca;border-radius:3px;margin-right:4px}.legend-square.answered{background:var(--green)}.legend-square.flagged{background:#e6b95c;border-color:#e6b95c}.palette-group{margin:20px 0}.palette-group h4{font-size:12px;margin:0 0 9px}.palette-grid{display:grid;grid-template-columns:repeat(6,minmax(0,1fr));gap:8px}.p-num{border:1px solid #d9e2db;color:var(--ink);background:#fff;border-radius:8px;height:36px;display:grid;place-items:center;font-weight:700;font-size:12px;position:relative}.p-num.done{background:var(--green-soft);border-color:#91b4a5;color:#16483c}.p-num.current{outline:2px solid var(--green);outline-offset:1px}.p-num.flagged:after{content:"";background:#cf9950;width:7px;height:7px;border-radius:50%;position:absolute;right:2px;top:2px}.p-num:hover{background:#e8f2eb}.save-indicator{display:flex;align-items:center;gap:7px;color:var(--muted);font-size:12px}.save-dot{display:inline-block;background:#4d987c;width:6px;height:6px;border-radius:50%}.exam-top-actions{display:flex;gap:9px}.result-wrap{max-width:1000px;margin:auto}.result-top{text-align:center;padding:28px 10px}.result-top h1{font-family:Georgia,serif;font-size:43px;font-weight:500;margin:10px 0}.metric-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}.metric{padding:25px}.metric .num{font-family:Georgia,serif;font-size:41px;line-height:1.2}.metric label{display:block;color:var(--muted);font-size:12px;margin-top:6px}.result-section{padding:25px;margin-top:16px}.result-section h2{font-size:18px;margin:0 0 17px}.result-table{width:100%;border-collapse:collapse;font-size:13px}.result-table th{text-align:left;color:var(--muted);font-weight:600}.result-table td,.result-table th{padding:11px;border-bottom:1px solid var(--line)}.result-table td:last-child,.result-table th:last-child{text-align:right}.alert{background:var(--warn-bg);padding:17px 19px;border:1px solid #ecd9bc;border-radius:12px;color:#72552e;font-size:13px}.private-file{display:flex;gap:10px;flex-wrap:wrap;align-items:center}.private-file input{max-width:270px;font-size:12px}.admin-layout{display:grid;grid-template-columns:325px minmax(0,1fr);gap:22px;align-items:start}.admin-sidebar{padding:18px;position:sticky;top:15px}.admin-editor{padding:26px}.admin-controls{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin:0 0 18px}.field{display:grid;gap:6px;margin-bottom:16px}.field label,.field-label{font-size:12px;font-weight:800;color:#4d6057}.input,.select,.textarea{background:#fff;border:1px solid #d8e2da;border-radius:10px;padding:10px 12px;color:var(--ink);width:100%;font-size:14px}.textarea{min-height:95px;resize:vertical}.input:focus,.select:focus,.textarea:focus{border-color:#79a38f;outline:2px solid #e4f2e9}.two-cols{display:grid;grid-template-columns:1fr 1fr;gap:12px}.admin-list{max-height:610px;overflow:auto;margin-top:11px;border-top:1px solid var(--line)}.admin-question{display:block;width:100%;padding:11px 8px;text-align:left;border:0;border-bottom:1px solid var(--line);background:white;font-size:12px}.admin-question.active{background:var(--green-soft)}.admin-question strong{font-size:11px;color:var(--green)}.admin-question span{display:block;color:var(--ink);margin-top:4px;line-height:1.35}.toolbar{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap;margin:15px 0}.no-data{text-align:center;padding:28px;color:var(--muted)}.modal-root:empty{display:none}.modal-root{position:fixed;inset:0;z-index:100;background:rgba(19,40,32,.48);display:grid;place-items:center;padding:20px}.modal-box{width:min(530px,100%);background:#fff;border-radius:20px;padding:27px;box-shadow:0 30px 100px #112f2645}.modal-box h2{font-size:22px;margin:0 0 7px}.modal-box p{font-size:14px;line-height:1.6;color:var(--muted)}.modal-actions{display:flex;justify-content:end;gap:9px;margin-top:25px;flex-wrap:wrap}.toast{position:fixed;bottom:25px;right:25px;z-index:200;background:var(--green);color:white;border-radius:12px;padding:13px 19px;box-shadow:0 9px 30px #163f3345;transform:translateY(100px);opacity:0;pointer-events:none;transition:.2s;font-size:13px}.toast.show{transform:translateY(0);opacity:1}.boot{text-align:center;margin:20vh auto;color:var(--muted)}.inline-actions{display:flex;gap:9px;align-items:center;flex-wrap:wrap}.empty-panel{padding:27px;text-align:center;color:var(--muted)}.info-strip{display:flex;justify-content:space-between;gap:12px;align-items:center;margin-bottom:15px}.hide-desktop{display:none}.side-note{font-size:12px;margin:12px 0;color:var(--muted)}
@media (max-width:1100px){.exam-layout{grid-template-columns:minmax(0,1fr) 260px}.palette-grid{grid-template-columns:repeat(5,minmax(0,1fr))}.question-panel{padding:25px}}
@media (max-width:850px){.shell{padding:0 17px}.topbar{height:70px}.container{padding:31px 17px 55px}.hero-mark{display:none}.exam-layout,.admin-layout{display:flex;flex-direction:column}.exam-main,.palette,.admin-sidebar,.admin-editor{width:100%}.palette{position:static;order:2}.exam-layout{padding-top:15px}.palette-grid{grid-template-columns:repeat(10,minmax(0,1fr))}.admin-sidebar{order:2}.admin-editor{order:1}.exam-context{align-items:start}.top-links .nav-btn{padding:8px}.cards{gap:13px}.exam-card{padding:20px}.question-count{font-size:54px}.hide-desktop{display:block}}
@media (max-width:600px){.cards,.metric-grid,.two-cols{grid-template-columns:1fr}.hero h1{font-size:40px}.hero{margin-top:0}.brand{font-size:15px;gap:8px}.brand-logo{width:35px;height:35px;font-size:20px}.brand-sub{font-size:9px}.top-links .nav-btn{font-size:11px;padding:6px}.question-panel{padding:22px 17px}.q-text{font-size:21px}.q-footer{flex-wrap:wrap}.q-footer>.btn{width:100%}.button-row{flex:1;justify-content:space-between}.exam-context{flex-wrap:wrap}.exam-context .progress-track{width:130px}.palette-grid{grid-template-columns:repeat(7,minmax(0,1fr))}.exam-top-actions .btn{font-size:11px;padding:8px}.attempt-card{flex-direction:column;align-items:stretch}.result-top h1{font-size:35px}.card-actions{flex-direction:column}}

/* Version 2 — kết quả từng câu và tệp tự luận riêng */
.review-tabs{display:flex;gap:9px;flex-wrap:wrap;margin:18px 0 19px}
.review-tab{border:1px solid #d4ded6;background:#f8faf7;border-radius:11px;padding:10px 13px;color:#4c6457;font-size:12px;font-weight:800}
.review-tab:hover{border-color:#8ab3a0}
.review-tab.selected{background:#15473d;border-color:#15473d;color:#fff}
.review-list{display:grid;gap:14px;max-height:900px;overflow:auto;padding-right:4px}
.review-item{border:1px solid #e1e8e1;background:white;border-radius:14px;padding:20px}
.review-item.wrong{border-left:4px solid #c36f5d}
.review-item.correct{border-left:4px solid #4a9c79}
.review-item.unanswered{border-left:4px solid #be934d}
.review-item.ungraded{border-left:4px solid #83938b}
.review-item-head{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:5px}
.review-pill{display:inline-block;border-radius:100px;padding:5px 11px;font-size:11px;font-weight:800;background:#f3f5f1;color:#57685e}
.review-pill.wrong{background:#fff0ee;color:#9c473f}
.review-pill.correct{background:#eaf5ee;color:#237d54}
.review-pill.unanswered{background:#fff4df;color:#8e6729}
.review-question{font-weight:700;line-height:1.6;margin:13px 0}
.review-options{display:grid;gap:6px}
.review-option{display:flex;align-items:flex-start;gap:11px;font-size:13px;line-height:1.6;padding:10px 12px;border-radius:9px;border:1px solid #edf0eb;background:#fff}
.review-option b{min-width:18px}
.review-option.right{background:#eef8f0;border-color:#c1e0c9}
.review-option.incorrect{background:#fff0ee;border-color:#ebc0bb}
.review-option-note{font-size:10px;letter-spacing:.01em;font-weight:800;margin-left:auto;white-space:nowrap;color:#486d56}
.review-option.incorrect .review-option-note{color:#a3453d}
.review-summary{font-size:12px;margin:14px 0 10px;color:var(--muted)}
.review-explain{font-size:13px;line-height:1.7;padding:13px 15px;background:#f3f6f0;border-radius:10px}
.review-empty{padding:25px;background:#f3f6f0;border-radius:12px;color:#4d6759;text-align:center}
@media(max-width:600px){.review-item{padding:14px}.review-option{flex-wrap:wrap}.review-option-note{margin-left:0}.result-section{padding:19px}}

/* Version 3 · cloud accounts, deadlines and admin tools */
.cloud-badge{background:#e3efe8;border:1px solid #bfdccc;padding:5px 10px;border-radius:99px;font-size:11px;color:#205f4a;font-weight:700}
.top-user{display:flex;align-items:center;gap:10px;font-size:12px;color:var(--muted);max-width:48vw}
.top-user span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.alert-error{background:#fff0ee;color:#893e35;border-color:#efc9c3}
.auth-wrap{min-height:76vh;display:grid;place-items:center;padding:25px}
.auth-panel{max-width:520px;width:100%;padding:45px;text-align:center}
.auth-panel h1{font-family:Georgia,serif;font-size:43px;margin:7px 0 13px}
.auth-panel p{color:var(--muted);line-height:1.8}
.deadline{font-size:12px;color:#906e37;font-weight:650;display:flex;gap:8px;align-items:center}
.deadline.hard{color:var(--red)}
.assignment-card{display:flex;flex-direction:column;gap:14px;padding:23px;border:1px solid var(--line);border-radius:16px;background:#fff}
.assignment-cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.assignment-card h3{margin:0;font-size:19px}
.assignment-meta{display:flex;gap:8px;flex-wrap:wrap;align-items:center;font-size:12px;color:var(--muted)}
.status-tag{background:#e6f2e9;color:#24644e;padding:5px 10px;border-radius:99px;font-size:11px;font-weight:800}
.status-tag.gray{background:#f2f1ec;color:#666f66}
.status-tag.amber{background:#fdf0d7;color:#97672c}
.dash-top{display:flex;justify-content:space-between;gap:18px;align-items:flex-end;margin-bottom:24px}
.dash-top h1{font-family:Georgia,serif;font-size:40px;font-weight:500;margin:6px 0 7px}
.empty-slate{background:white;padding:35px;border:1px dashed var(--line);border-radius:18px;text-align:center;color:var(--muted)}
.exam-sub{font-size:12px;color:var(--muted);margin-top:12px}
.topline-tools{display:flex;gap:9px;align-items:center;flex-wrap:wrap}
.admin-tabs{display:flex;gap:9px;flex-wrap:wrap;margin:12px 0 24px}
.admin-tabs button.selected{background:var(--green);color:white}
.admin-questions{display:grid;grid-template-columns:315px 1fr;gap:18px;align-items:start}
.admin-q-list{max-height:66vh;overflow:auto;border:1px solid var(--line);border-radius:14px;background:white}
.admin-q-list button{display:block;width:100%;text-align:left;background:white;border:0;border-bottom:1px solid var(--line);padding:12px}
.admin-q-list button.active{background:var(--green-soft)}
.admin-q-list small{display:block;margin-top:4px;color:var(--muted);line-height:1.5}
.admin-q-form{border:1px solid var(--line);border-radius:14px;background:white;padding:24px}
.admin-q-form h3{margin-top:0}
.inline-field{display:flex;gap:12px;flex-wrap:wrap;align-items:end}
.inline-field>.field{flex:1;min-width:190px}
.admin-table{width:100%;border-collapse:collapse;background:white;font-size:13px}
.admin-table td,.admin-table th{border-bottom:1px solid var(--line);padding:12px;text-align:left;vertical-align:top}
.admin-table th{font-size:11px;color:var(--muted);font-weight:800}
.admin-table-wrap{overflow:auto;border:1px solid var(--line);border-radius:13px}
.smallbtn{background:white;border:1px solid #d1ddd2;border-radius:8px;padding:6px 10px;font-size:12px}
.smallbtn:hover{background:#f1f6f1}
.notice{background:#f3f7f3;padding:12px 15px;border-radius:10px;color:#355e49;font-size:12px;line-height:1.7}
.save-pill{font-size:12px;color:var(--muted);padding:8px 11px;background:#f0f4ef;border-radius:99px}
.save-pill.dirty{color:#a16523;background:#fff2db}
.save-pill.failed{color:#a3433b;background:#fff0eb}
.essay-preview{white-space:pre-wrap;word-break:break-word;line-height:1.8;border-radius:12px;background:#f4f6f2;padding:17px}
footer.copyright{font-size:12px;color:var(--muted);padding:24px 0 45px}
@media(max-width:850px){.assignment-cards{grid-template-columns:1fr}.admin-questions{grid-template-columns:1fr}.admin-q-list{max-height:230px}.dash-top{align-items:flex-start;flex-direction:column}.top-user{max-width:50vw}.auth-panel{padding:27px}.admin-q-form{padding:16px}}
@media(max-width:600px){.top-user span{display:none}.dash-top h1{font-size:33px}.auth-panel h1{font-size:36px}.admin-table td,.admin-table th{padding:8px}.exam-sub{font-size:11px}}

@media(max-width:600px){.topbar{height:auto;min-height:70px}.topbar .shell{flex-wrap:wrap;padding-top:10px;padding-bottom:10px}.topline-tools{flex-wrap:wrap;justify-content:flex-end;gap:4px}.topline-tools .nav-btn{font-size:11px;padding:6px 8px}.top-user{max-width:none}.top-user .cloud-badge{display:none}.brand{flex:1;min-width:134px}.top-user span:first-child{display:none}}

/* v3.1 — self-service exams and participant-owned deadlines */
[hidden]{display:none!important}
.self-start{padding:27px 30px;margin-bottom:30px;border-color:#bfd4c6;background:linear-gradient(120deg,#f8fcf9,#fff)}
.self-start h2{font-size:24px;letter-spacing:-.025em;margin:7px 0 3px}
.self-start-title{display:flex;justify-content:space-between;align-items:start;gap:16px;margin-bottom:20px}
.self-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;align-items:end}
.self-start .inline-actions{margin-top:3px}
.section-heading{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:14px}
.section-heading h2{font-size:21px;margin:0}
.origin-label{background:#edf3f0;color:#2f6354;border-radius:999px;font-size:11px;font-weight:800;padding:4px 10px}
.self-deadline-editor{margin-top:16px;background:#f5f9f5;border:1px solid #dce9de;border-radius:12px;padding:17px}
.self-deadline-editor .self-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
.self-deadline-editor .inline-actions{margin-top:8px}
.assignment-card .card-actions{margin-top:auto;flex-wrap:wrap}
.assignment-card .card-actions .btn{flex-grow:1}
@media(max-width:850px){.self-grid{grid-template-columns:1fr 1fr}.self-start{padding:21px}}
@media(max-width:600px){.self-grid,.self-deadline-editor .self-grid{grid-template-columns:1fr}.self-start-title{flex-direction:column}.section-heading{align-items:flex-start;flex-direction:column}.self-start{padding:20px}.assignment-card .card-actions .btn{width:100%}}