@font-face{font-family:Practice;src:local("Segoe UI")} :root{color-scheme:dark;--bg:#101114;--panel:#191b20;--panel2:#202228;--line:#2b2e36;--muted:#9b9eab;--text:#f3f3f5;--red:#e32348;--pink:#ff6b87;--green:#80dba5;--side:250px}*{box-sizing:border-box}[hidden]{display:none!important}body{margin:0;background:var(--bg);color:var(--text);font:15px/1.6 Practice,"Segoe UI",Arial,sans-serif}button,input,select,textarea{font:inherit}button,a,input,select,textarea,summary{-webkit-tap-highlight-color:transparent}button,a{touch-action:manipulation}a{color:inherit;text-decoration:none}button{cursor:pointer}button:disabled{opacity:.45;cursor:default}button,input,select,textarea{border-radius:9px}button{border:1px solid var(--line);background:var(--panel2);color:var(--text);padding:10px 15px}button:hover:not(:disabled){border-color:#646773}button.primary,.primary{background:var(--red);border-color:var(--red);color:#fff;font-weight:600}button.primary:hover:not(:disabled){background:#f33559;border-color:#f33559}:focus-visible{outline:3px solid var(--pink);outline-offset:4px}input,select,textarea{background:#101216;color:var(--text);border:1px solid #424550;padding:11px 13px;min-width:0}input:not([type=checkbox]):not([type=radio]),select,textarea{width:100%}textarea{min-height:140px;resize:vertical}input[type=checkbox],input[type=radio]{accent-color:var(--red);width:18px;height:18px;flex-shrink:0}label{display:block}label.field{font-size:13px;color:var(--muted)}label.field>input,label.field>select{margin-top:7px}.sidebar{position:fixed;inset:0 auto 0 0;width:var(--side);background:#15161a;border-right:1px solid var(--line);padding:30px 20px;display:flex;flex-direction:column;z-index:5}.brand{display:flex;gap:11px;align-items:center;font-size:19px;font-weight:750;letter-spacing:-.4px}.brand-icon{display:grid;place-items:center;background:var(--red);border-radius:12px;width:42px;height:44px;font-size:18px;color:white}.brand-red{color:var(--pink)}.brand small{display:block;letter-spacing:1.2px;color:#868995;font-size:8px;font-weight:500;margin-top:3px}.sidebar-label{font-size:9px;color:#727683;letter-spacing:1.7px;margin:48px 12px 15px}.sidebar nav{display:grid;gap:8px}.sidebar nav a{display:flex;align-items:center;gap:12px;color:#a8abb5;padding:12px;border-radius:9px;font-size:13px}.sidebar nav a span{font-size:22px;line-height:1;width:22px;color:#8b8e99}.sidebar nav a:hover{background:var(--panel2);color:#fff}.sidebar nav a.active{background:#e3234816;color:#ff7892}.sidebar nav a.active span{color:#ff7892}.sidebar-bottom{margin-top:auto;font-size:11px;color:#c0c2cb;padding:25px 10px 0;border-top:1px solid var(--line)}.sidebar-bottom p{color:#858995;line-height:1.8;margin:12px 0 18px}.sidebar-bottom a{color:#c0c2cb}.live-dot{display:inline-block;width:6px;height:6px;border-radius:50%;background:var(--green);margin-right:5px}.workspace{margin-left:var(--side)}.topbar{height:81px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);padding:0 42px;color:var(--muted);font-size:12px}.topbar b{color:#d9dae0;font-weight:500;margin-left:7px}.quiet-button{display:inline-flex;gap:24px;padding:9px 15px;border:1px solid var(--line);border-radius:8px;color:#d7d8df}.quiet-button:hover{border-color:#626675}main{max-width:1320px;margin:auto;padding:42px}.eyebrow{color:var(--pink);font-size:10px;font-weight:650;letter-spacing:2px;margin:0 0 15px}.hero{position:relative;overflow:hidden;padding:34px 36px 30px;background:linear-gradient(110deg,#241a21,#1b1b22 65%,#26171f);border:1px solid #49303c;border-radius:17px}.hero h1{font-size:clamp(28px,3vw,42px);line-height:1.18;letter-spacing:-1.1px;margin:0 0 15px;max-width:700px}.hero p:not(.eyebrow){color:#b1a8b2;max-width:560px;font-size:13px;margin:0}.hero-tags{display:flex;gap:24px;margin-top:25px;color:#c4bac5;font-size:11px}.hero-tags span::before{content:'✓';color:var(--pink);margin-right:8px}.section-heading{display:flex;justify-content:space-between;align-items:center;gap:15px;margin:32px 0 16px}.section-heading h2{font-size:18px;margin:0;font-weight:600}.muted{color:var(--muted)}.small{font-size:12px}.section-heading .muted{font-size:11px}.subjects{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:17px}.subject-card{padding:25px;background:var(--panel);border:1px solid var(--line);border-radius:13px;display:flex;flex-direction:column;align-items:stretch;text-align:left;transition:transform .15s,border-color .15s}.subject-card:hover{border-color:#a84358;transform:translateY(-2px)}.subject-card-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:22px}.subject-icon{width:45px;height:45px;display:grid;place-items:center;font-size:23px;color:var(--pink);background:#df24471a;border:1px solid #7d2c3b50;border-radius:10px}.badge{font-size:10px;color:#a8aab4;border:1px solid #383b45;border-radius:6px;padding:3px 8px;white-space:nowrap}.subject-card h3{font-size:21px;letter-spacing:-.4px;margin:0 0 5px}.subject-card p{font-size:12px;color:var(--muted);margin:0 0 24px}.subject-card-bottom{display:flex;align-items:center;justify-content:space-between;border-top:1px solid var(--line);padding-top:16px;color:var(--muted);font-size:11px}.subject-card-bottom b{color:#e0e1e7;font-weight:500}.card-arrow{color:var(--pink);font-size:20px}.home-bottom{display:grid;grid-template-columns:1.4fr 1fr;gap:17px;margin-top:26px}.panel{background:var(--panel);border:1px solid var(--line);border-radius:13px;padding:24px}.panel h2,.panel h3{margin:0 0 9px;font-size:18px}.panel p{font-size:12px;color:var(--muted)}.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.row>input{flex:1;min-width:140px}.row.spread{justify-content:space-between}.page-heading h1{font-size:30px;line-height:1.2;letter-spacing:-.7px;margin:0 0 12px}.page-heading p{margin:0 0 26px;color:var(--muted);font-size:13px}.tabs{display:flex;gap:8px;margin:23px 0;flex-wrap:wrap}.tabs button.active{border-color:#ab3d54;background:#e3234814;color:var(--pink)}.filters{display:grid;grid-template-columns:1fr 1.4fr 1fr;gap:12px;margin:18px 0}.catalog-grid{display:grid;grid-template-columns:1fr 1fr;gap:15px}.task-preview{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:20px;display:flex;flex-direction:column;gap:15px}.task-meta{display:flex;justify-content:space-between;gap:12px;align-items:center;font-size:11px;color:var(--muted)}.task-preview h3{font-size:14px;line-height:1.65;font-weight:400;margin:0;display:-webkit-box;-webkit-line-clamp:4;-webkit-box-orient:vertical;overflow:hidden;min-height:90px}.task-preview .topic{color:#9296a3;font-size:11px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.task-preview .row{margin-top:auto;justify-content:space-between}.task-preview label{display:flex;gap:7px;align-items:center;font-size:11px;color:#b6b9c3}.pagination{display:flex;justify-content:center;align-items:center;gap:18px;margin:28px 0;color:var(--muted);font-size:12px}.selection-bar{border:1px solid #793349;background:#271a22;padding:15px 20px;border-radius:10px;margin:20px 0;display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap}.variant-settings{display:grid;grid-template-columns:1fr 1fr 1fr;gap:15px}.variant-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-top:24px}.variant-button{padding:20px;text-align:left;display:flex;flex-direction:column;gap:7px;background:var(--panel)}.variant-button span{font-size:11px;color:var(--muted)}.variant-button b{font-size:17px;font-weight:600}.notice{font-size:12px;color:#b6b9c6;line-height:1.8;border-left:2px solid #a0445a;padding:8px 14px;margin:20px 0}.exercise-layout{display:grid;grid-template-columns:minmax(0,1fr) 215px;gap:20px;align-items:start;margin-top:24px}.exercise-main{min-width:0}.task-paper{padding:28px;background:#fff;color:#191b20;border-radius:11px;font-family:"Segoe UI",Arial,sans-serif;font-size:16px;line-height:1.7;overflow:auto}.task-paper p:first-child{margin-top:0}.task-paper p{margin:10px 0}.task-paper img{max-width:100%;height:auto;vertical-align:middle}.task-paper a{color:#a21637;text-decoration:underline}.task-paper table{border-collapse:collapse;max-width:100%;margin:12px 0}.task-paper td,.task-paper th{border:1px solid #b6bac3;padding:6px 10px;vertical-align:top}.task-paper math{font-size:1.15em;color:#111}.task-paper .answer-choice{border:1px solid #d1d3da;background:#fafafa;color:#15171c;padding:12px;display:flex;gap:12px;align-items:flex-start;border-radius:8px;margin:9px 0}.task-paper .answer-choice:has(input:checked){border-color:#d51b40;background:#fff0f4}.task-paper .answer-choice p{margin:0}.answer-panel{margin-top:18px;padding:22px;background:var(--panel);border:1px solid var(--line);border-radius:12px}.answer-panel label{font-size:12px;color:var(--muted);margin-bottom:9px}.sequence-inputs{display:flex;gap:8px;flex-wrap:wrap}.sequence-inputs select{width:65px}.answer-panel .row{margin-top:14px}.feedback{margin:12px 0 0;font-size:13px;min-height:24px}.feedback.correct{color:var(--green)}.feedback.wrong,.feedback.error{color:#ff8298}.feedback.manual,.feedback.partial,.feedback.unavailable{color:#f6c87c}.feedback.blank{color:var(--muted)}.question-nav{position:sticky;top:20px}.question-nav h3{font-size:12px;margin:0 0 14px;font-weight:500;color:var(--muted)}.number-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.number-grid button{padding:7px 0;font-size:12px}.number-grid .current{border-color:var(--red);color:var(--pink)}.number-grid .answered{background:#37303b}.number-grid .correct{background:#173626;color:#9de9b7}.number-grid .wrong{background:#4b202b;color:#ffb1c0}.question-nav p{font-size:11px;color:var(--muted)}.question-nav>.primary{width:100%;margin-top:14px}.task-toolbar{display:flex;align-items:center;justify-content:space-between;gap:16px;font-size:12px;color:var(--muted);margin-bottom:16px}.task-toolbar a{text-decoration:underline}.exercise-controls{display:flex;justify-content:space-between;gap:12px;margin-top:18px}.result-score{font-size:40px;line-height:1.2;color:var(--green);font-weight:650}.result-table{width:100%;border-collapse:collapse;margin-top:22px;font-size:13px}.result-table td,.result-table th{text-align:left;border-bottom:1px solid var(--line);padding:13px 9px;vertical-align:top}.result-table th{color:var(--muted);font-size:11px;font-weight:500}.result-table button{font-size:11px;padding:6px 10px}.empty{padding:50px 20px;text-align:center;border:1px dashed var(--line);border-radius:12px;color:var(--muted)}.error-panel{padding:30px;border:1px solid #8c3d4d;background:#2c1920;border-radius:12px}.error-panel p{color:#e6b6c1}.teacher-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}.teacher-item{padding:17px 0;border-bottom:1px solid var(--line)}.teacher-item h3{font-size:15px;margin:0 0 7px}.teacher-item p{font-size:12px;margin:6px 0;color:var(--muted)}.teacher-item code{color:var(--pink);font-size:16px;letter-spacing:1px}.file-list{font-size:12px;margin-top:10px;color:var(--muted)}.file-list button{font-size:11px}.file-note{font-size:11px;color:var(--muted)}dialog{border:1px solid #41444e;border-radius:16px;background:var(--bg);color:var(--text);width:min(900px,calc(100% - 30px));max-height:90vh;padding:28px}dialog::backdrop{background:#000b;backdrop-filter:blur(3px)}.dialog-head{display:flex;justify-content:space-between;gap:20px;align-items:center;margin-bottom:20px}.dialog-head h2{font-size:18px;margin:0}.close-dialog{font-size:22px;padding:0 9px;background:transparent}.solution{margin-top:18px;padding:20px;border:1px solid #3d414c;border-radius:10px;white-space:pre-wrap;font-size:14px}.loading{color:var(--muted);padding:40px 0}.busy{opacity:.6;pointer-events:none}#toast{position:fixed;bottom:25px;left:calc(var(--side) + 25px);right:25px;max-width:600px;padding:15px 20px;background:#31333d;border:1px solid #5a5e6c;border-radius:10px;z-index:30;font-size:13px}footer{max-width:1320px;margin:auto;padding:10px 42px 25px;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;color:#747987;font-size:10px}.review-item{border-top:1px solid var(--line);padding:22px 0}.review-item .row{margin-top:12px}.review-item input[type=number]{max-width:90px}.review-answer{white-space:pre-wrap;overflow-wrap:anywhere;font-size:14px;background:var(--panel2);padding:15px;border-radius:8px}button.link-button{padding:0;border:0;background:none;color:var(--pink);font-size:12px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@media(max-width:1150px){:root{--side:220px}main{padding:30px}.topbar{padding:0 30px}.sidebar{padding:26px 14px}.brand{font-size:17px}.variant-grid{grid-template-columns:repeat(3,1fr)}.filters{grid-template-columns:1fr 1fr}.filters label:last-child{grid-column:1/-1}.home-bottom{grid-template-columns:1fr}.exercise-layout{grid-template-columns:minmax(0,1fr) 180px}.task-paper{padding:20px}}@media(max-width:800px){:root{--side:0px}.sidebar{position:static;width:auto;padding:18px 20px;border-right:0;border-bottom:1px solid var(--line)}.sidebar nav{display:flex;overflow:auto;gap:5px;margin-top:18px}.sidebar nav a{white-space:nowrap;padding:8px 10px;font-size:11px}.sidebar nav a span{display:none}.sidebar-label,.sidebar-bottom{display:none}.workspace{margin-left:0}.topbar{height:60px;padding:0 20px}main{padding:24px 20px}.hero{padding:25px}.hero-tags{gap:12px;flex-wrap:wrap}.subject-card{padding:20px}.exercise-layout{grid-template-columns:1fr}.question-nav{position:static;grid-row:1;padding:16px}.number-grid{display:flex;flex-wrap:wrap}.number-grid button{width:36px}.question-nav h3,.question-nav p{display:none}.question-nav>.primary{width:auto;font-size:12px;margin-top:12px}.teacher-grid{grid-template-columns:1fr}footer{padding:10px 20px 20px}.task-paper{font-size:15px}.task-paper table{font-size:12px}}@media(max-width:540px){.subjects,.catalog-grid{grid-template-columns:1fr}.filters,.variant-settings{grid-template-columns:1fr}.filters label:last-child{grid-column:auto}.variant-grid{grid-template-columns:repeat(2,1fr)}.hero h1{font-size:29px}.hero{padding:23px}.hero-tags span:last-child{display:none}.subject-card-top{margin-bottom:16px}.subject-card p{margin-bottom:18px}.subject-card h3{font-size:22px}.topbar{font-size:11px}.topbar .quiet-button{gap:12px;padding:7px 9px}.section-heading .muted{display:none}.task-paper{padding:16px}.result-table{font-size:11px}.result-table td,.result-table th{padding:10px 5px}.task-toolbar{align-items:flex-start;flex-direction:column}.answer-panel .row>button{flex:1}.task-meta{flex-wrap:wrap}.task-preview h3{min-height:0}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}@media print{.sidebar,.topbar,.question-nav,.answer-panel,.exercise-controls,footer,.quiet-button,#toast{display:none!important}.workspace{margin:0}body{background:white;color:black}main{padding:0}.task-paper{border:1px solid #ccc}.hero{background:white;color:black}}