:root{--bg:#f4f6f9;--card:#fff;--ink:#18222e;--muted:#566274;--line:#d9dfe7;--accent:#1f4e79;--accent-ink:#fff;--accent-soft:#e6eef7;--ok:#1d6b4b;--ok-soft:#e3f4ec;--bad:#b42318;--bad-soft:#fdeceb;--warn:#8a5300;--warn-soft:#fff3dc;--focus:#0b63ce;--radius:12px;--ui:system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;--serif:Cambria, "Cambria Math", Georgia, "Times New Roman", serif}*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}body{background:var(--bg);color:var(--ink);font:16px/1.5 var(--ui);margin:0}h1{margin:0 0 .75rem;font-size:1.45rem;line-height:1.25}h2{margin:0 0 .6rem;font-size:1.15rem}h3{margin:0 0 .4rem;font-size:1rem}a{color:var(--accent)}:focus-visible{outline:3px solid var(--focus);outline-offset:2px;border-radius:4px}.sr-only{clip:rect(0 0 0 0);white-space:nowrap;width:1px;height:1px;position:absolute;overflow:hidden}.skip{z-index:100;background:#fff;padding:.5rem 1rem;position:absolute;top:0;left:-999px}.skip:focus{top:8px;left:8px}.topbar{background:var(--accent);color:#fff;z-index:20;position:sticky;top:0}.topbar-in{align-items:center;gap:16px;max-width:1100px;min-height:52px;margin:0 auto;padding:0 16px;display:flex}.brand{color:#fff;white-space:nowrap;font-weight:700;text-decoration:none}.nav{scrollbar-width:none;flex:1;gap:2px;display:flex;overflow-x:auto}.nav::-webkit-scrollbar{display:none}.nav a{color:#dbe7f3;white-space:nowrap;border-bottom:3px solid #0000;padding:14px 12px;font-size:.95rem;text-decoration:none}.nav a.active{color:#fff;border-bottom-color:#fff;font-weight:600}.nav a:hover{color:#fff}.who{color:#dbe7f3;white-space:nowrap;font-size:.85rem}main{max-width:1100px;margin:0 auto;padding:16px 16px 90px}main.narrow{max-width:640px}.bottomnav{display:none}@media (width<=640px){.nav.top-student,.who{display:none}.bottomnav{border-top:1px solid var(--line);z-index:20;background:#fff;grid-template-columns:repeat(4,1fr);display:grid;position:fixed;bottom:0;left:0;right:0}.bottomnav a{text-align:center;color:var(--muted);min-height:52px;padding:10px 4px 12px;font-size:.8rem;text-decoration:none}.bottomnav a.active{color:var(--accent);box-shadow:inset 0 3px 0 var(--accent);font-weight:700}.bottomnav .ico{font-size:1.25rem;line-height:1.3;display:block}}.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);margin-bottom:16px;padding:16px}.card.flush{padding:0;overflow:hidden}.grid{gap:16px;display:grid}.g2{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}.tiles{grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;margin-bottom:16px;display:grid}.tile{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:14px}.tile .n{font-size:1.6rem;font-weight:700;line-height:1.2}.tile .l{color:var(--muted);font-size:.85rem}.muted{color:var(--muted)}.small{font-size:.85rem}.row{flex-wrap:wrap;align-items:center;gap:10px;display:flex}.row.between{justify-content:space-between}.stack>*+*{margin-top:12px}.badge{background:var(--accent-soft);color:var(--accent);vertical-align:middle;border-radius:999px;padding:2px 8px;font-size:.75rem;font-weight:600;display:inline-block}.badge.ok{background:var(--ok-soft);color:var(--ok)}.badge.bad{background:var(--bad-soft);color:var(--bad)}.badge.warn{background:var(--warn-soft);color:var(--warn)}.badge.gray{color:var(--muted);background:#eceff3}label{margin-bottom:4px;font-size:.9rem;font-weight:600;display:block}input[type=text],input[type=email],input[type=password],input[type=number],input[type=search],input[type=datetime-local],select,textarea{width:100%;min-height:44px;font:inherit;color:var(--ink);background:#fff;border:1px solid #aab4c1;border-radius:8px;padding:8px 12px}textarea{resize:vertical;min-height:110px}.field{margin-bottom:14px}.hint{color:var(--muted);margin-top:4px;font-size:.82rem}.check{cursor:pointer;align-items:center;gap:10px;min-height:44px;margin:0;font-weight:400;display:flex}.check input{flex:none;width:22px;height:22px}.btn{border:1px solid var(--accent);background:var(--accent);color:#fff;min-height:44px;font:inherit;cursor:pointer;border-radius:8px;justify-content:center;align-items:center;gap:6px;padding:8px 18px;font-weight:600;text-decoration:none;display:inline-flex}.btn:hover{filter:brightness(1.1)}.btn[disabled]{opacity:.5;cursor:not-allowed}.btn.secondary{color:var(--accent);background:#fff}.btn.danger{background:var(--bad);border-color:var(--bad)}.btn.ghost{color:var(--accent);background:0 0;border-color:#0000}.btn.big{min-height:52px;padding:10px 26px;font-size:1.05rem}.btn.sm{min-height:36px;padding:4px 12px;font-size:.88rem}.btn.block{width:100%}.seg{flex-wrap:wrap;gap:8px;display:flex}.seg label{margin:0}.seg input{opacity:0;pointer-events:none;position:absolute}.seg span{cursor:pointer;background:#fff;border:1px solid #aab4c1;border-radius:8px;align-items:center;min-height:44px;padding:8px 16px;font-weight:600;display:inline-flex}.seg input:checked+span{background:var(--accent);color:#fff;border-color:var(--accent)}.seg input:focus-visible+span{outline:3px solid var(--focus);outline-offset:2px}.alert{border:1px solid;border-radius:8px;margin-bottom:14px;padding:10px 14px}.alert.err{background:var(--bad-soft);color:#7a1710;border-color:#f2b8b3}.alert.info{background:var(--accent-soft);border-color:#b7cde4}.alert.ok{background:var(--ok-soft);color:#134d35;border-color:#a9d9c2}.alert.warn{background:var(--warn-soft);color:#5c3700;border-color:#f0cf8e}.banner{background:var(--accent);color:#fff;border-radius:var(--radius);flex-wrap:wrap;justify-content:space-between;align-items:center;gap:14px;margin-bottom:16px;padding:16px;display:flex}.banner .btn{color:var(--accent);background:#fff;border-color:#fff}.auth-box{max-width:440px;margin:24px auto}.tbl-wrap{overflow-x:auto}table.tbl{border-collapse:collapse;width:100%;font-size:.92rem}.tbl th,.tbl td{text-align:left;border-bottom:1px solid var(--line);vertical-align:top;padding:9px 12px}.tbl th{text-transform:uppercase;letter-spacing:.03em;color:var(--muted);white-space:nowrap;background:#f0f3f7;font-size:.8rem}.tbl td.num,.tbl th.num{text-align:right}.tbl tr.me td{background:var(--accent-soft);font-weight:600}.tabs{gap:6px;margin-bottom:14px;display:flex}.tabs button{min-height:44px;font:inherit;cursor:pointer;background:#fff;border:1px solid #aab4c1;border-radius:8px;flex:1;font-weight:600}.tabs button[aria-selected=true]{background:var(--accent);color:#fff;border-color:var(--accent)}.list{margin:0;padding:0;list-style:none}.list li{border-bottom:1px solid var(--line);padding:12px 0}.list li:last-child{border-bottom:0}.bar{background:#e6eaf0;border-radius:4px;min-width:60px;height:8px;overflow:hidden}.bar>i{background:var(--accent);height:100%;display:block}.pager{justify-content:flex-end;align-items:center;gap:10px;margin-top:10px;display:flex}.rich{font-family:var(--serif);overflow-wrap:anywhere;font-size:1.06rem;line-height:1.55}.rich p{margin:0 0 .7em}.rich p:last-child{margin-bottom:0}.rich .table-wrap{max-width:100%;margin:.5em 0 .8em;overflow-x:auto}.rich table{border-collapse:collapse;font-family:var(--serif);min-width:55%;font-size:11pt}.rich th,.rich td{text-align:left;vertical-align:top;border:1px solid #8793a3;padding:.1cm}.rich th{background:#eef2f7;font-weight:700}.rich td.num,.rich th.num{text-align:right;white-space:nowrap}.test-top{z-index:15;border-bottom:1px solid var(--line);background:#fff;position:sticky;top:0}.test-top-in{justify-content:space-between;align-items:center;gap:12px;max-width:900px;margin:0 auto;padding:8px 16px;display:flex}.timer{font-variant-numeric:tabular-nums;background:var(--accent-soft);color:var(--accent);border-radius:8px;padding:4px 12px;font-size:1.35rem;font-weight:700}.timer.low{background:var(--bad-soft);color:var(--bad)}.test-wrap{max-width:900px;margin:0 auto;padding:16px 16px 120px}.qno{color:var(--muted);flex-wrap:wrap;justify-content:space-between;gap:8px;margin-bottom:6px;font-weight:700;display:flex}.options{gap:10px;margin-top:16px;display:grid}.opt{text-align:left;width:100%;min-height:60px;font:inherit;color:inherit;cursor:pointer;background:#fff;border:2px solid #b7c0cc;border-radius:12px;align-items:flex-start;gap:12px;padding:12px 14px;display:flex}.opt:hover{border-color:var(--accent)}.opt .letter{width:34px;height:34px;color:var(--accent);font-weight:700;font-family:var(--ui);background:#eef2f7;border-radius:50%;flex:none;justify-content:center;align-items:center;display:inline-flex}.opt[aria-pressed=true]{border-color:var(--accent);background:var(--accent-soft)}.opt[aria-pressed=true] .letter{background:var(--accent);color:#fff}.opt .rich{flex:1;padding-top:3px}.testbar{border-top:1px solid var(--line);z-index:15;background:#fff;position:fixed;bottom:0;left:0;right:0}.testbar-in{justify-content:space-between;align-items:center;gap:8px;max-width:900px;margin:0 auto;padding:8px 16px;display:flex}.palette{grid-template-columns:repeat(auto-fill,minmax(44px,1fr));gap:8px;display:grid}.pal{min-height:44px;font:inherit;cursor:pointer;background:#fff;border:2px solid #b7c0cc;border-radius:8px;font-weight:700;position:relative}.pal.answered{background:var(--ok-soft);border-color:var(--ok);color:var(--ok)}.pal.marked:after{content:"";background:var(--warn);border:1px solid #fff;border-radius:50%;width:10px;height:10px;position:absolute;top:3px;right:3px}.pal.current{outline:3px solid var(--accent);outline-offset:1px}.legend{color:var(--muted);flex-wrap:wrap;gap:14px;margin-top:10px;font-size:.82rem;display:flex}.legend i{vertical-align:-2px;border:2px solid #b7c0cc;border-radius:4px;width:14px;height:14px;margin-right:4px;display:inline-block}.legend i.a{background:var(--ok-soft);border-color:var(--ok)}.legend i.m{background:var(--warn);border-color:var(--warn);border-radius:50%}.modal-bg{z-index:50;background:#0f19288c;justify-content:center;align-items:center;padding:16px;display:flex;position:fixed;inset:0}.modal{background:#fff;border-radius:14px;width:100%;max-width:460px;max-height:90vh;padding:20px;overflow:auto}.modal.wide{max-width:860px}.modal h2{margin-top:0}.modal .actions{flex-wrap:wrap;justify-content:flex-end;gap:10px;margin-top:16px;display:flex}.rv-opt{border:1px solid var(--line);border-radius:8px;align-items:flex-start;gap:10px;margin-top:8px;padding:8px 10px;display:flex}.rv-opt .letter{width:28px;font-weight:700;font-family:var(--ui);flex:none}.rv-opt.correct{background:var(--ok-soft);border-color:var(--ok)}.rv-opt.wrong{background:var(--bad-soft);border-color:var(--bad)}.rv-opt .tag{font-size:.75rem;font-weight:700;font-family:var(--ui);flex:none;margin-left:auto}.solution{border-left:4px solid var(--accent);background:#f7f9fc;border-radius:6px;margin-top:12px;padding:12px 14px}.score-hero{text-align:center;padding:22px 16px}.score-hero .big{font-size:3rem;font-weight:800;line-height:1.1}.kv{text-align:left;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:10px;margin-top:14px;display:grid}.kv div{background:#f4f6f9;border-radius:8px;padding:8px 12px}.kv b{font-size:1.1rem;display:block}.chap-list{border:1px solid var(--line);border-radius:8px;max-height:320px;padding:4px 12px;overflow:auto}.spin{border:3px solid #c9d4e2;border-top-color:var(--accent);vertical-align:middle;border-radius:50%;width:22px;height:22px;animation:.8s linear infinite sp;display:inline-block}@keyframes sp{to{transform:rotate(360deg)}}@media (prefers-reduced-motion:reduce){.spin{animation-duration:3s}}.nav{min-width:0}@media (width<=1180px){.who{display:none}}