:root{--ink:#1b2430;--muted:#5c6674;--paper:#f3efe6;--card:#fffdf8;--line:#d9d1c3;--blue:#2b6ea3;--blue-dark:#1e4f78;--yellow:#e6c35c;--ok:#2f6f4e;--err:#a33b32;--shadow:0 18px 40px #1b243014;--sans:"Segoe UI", "PT Sans", system-ui, sans-serif;--mono:"Cascadia Code", "Consolas", ui-monospace, monospace}*{box-sizing:border-box}html,body,#root{min-height:100%}body{color:var(--ink);font:16px/1.5 var(--sans);background:radial-gradient(circle at top left, #2b6ea31f, transparent 28%), repeating-linear-gradient(0deg, transparent, transparent 27px, #2b6ea30a 28px), var(--paper);margin:0}h1,h2{letter-spacing:-.03em;margin:0 0 8px}h1{font-size:2rem}h2{font-size:1.15rem}button,input,textarea,select{font:inherit}button{cursor:pointer;background:var(--blue);color:#fff;border:0;border-radius:10px;justify-content:center;align-items:center;gap:8px;padding:10px 16px;display:inline-flex}button:hover:not(:disabled){background:var(--blue-dark)}button:disabled{opacity:.55;cursor:not-allowed}button.ghost{color:var(--blue-dark);border:1px solid var(--line);background:0 0}button.ghost:hover:not(:disabled){background:#2b6ea314}a.nav-btn,a.work-card,a.table-col{text-decoration:none}a.nav-btn{cursor:pointer;background:var(--blue);color:#fff;text-align:center;border:0;border-radius:10px;justify-content:center;align-items:center;gap:8px;padding:10px 16px;display:inline-flex}a.nav-btn:hover{background:var(--blue-dark)}a.nav-btn.ghost{color:var(--blue-dark);border:1px solid var(--line);background:0 0}a.nav-btn.ghost:hover{background:#2b6ea314}form>a.nav-btn{display:block}a.table-col{color:inherit}.shell{width:min(920px,100% - 32px);margin:0 auto;padding:24px 0 64px}.shell.is-wide{width:min(1240px,100% - 32px)}.filter{min-width:160px}.login-shell{place-items:center;min-height:100svh;display:grid}.login-card,.work-card,.task,.topbar{background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow)}.login-card{border-radius:18px;width:min(460px,100%);padding:32px}.eyebrow{text-transform:uppercase;letter-spacing:.14em;color:var(--blue-dark);margin:0 0 8px;font-size:.75rem;font-weight:700}.lead,.muted{color:var(--muted)}.lead{margin:0 0 24px}form{gap:14px;display:grid}label{gap:6px;font-weight:600;display:grid}input,textarea,select{border:1px solid var(--line);width:100%;color:var(--ink);background:#fff;border-radius:10px;padding:10px 12px}textarea{font-family:var(--mono);resize:vertical}.topbar{border-radius:16px;flex-direction:column;align-items:stretch;gap:14px;margin-bottom:28px;padding:16px 20px;display:flex}.topbar-main{justify-content:space-between;align-items:center;gap:16px;display:flex}.admin-nav{flex-wrap:wrap;gap:8px;display:flex}.page-nav{flex-wrap:wrap;gap:8px;margin-bottom:18px;display:flex}.page-nav .back{margin-bottom:0}.work-grid{gap:16px;display:grid}.work-card{text-align:left;color:inherit;background:var(--card);border-radius:16px;gap:10px;padding:20px;display:grid}.work-card p{color:var(--muted);margin:0}.badge{color:#6d5720;background:#efe6cd;border-radius:999px;width:fit-content;padding:4px 10px;font-size:.8rem;font-weight:700}.badge.done{color:var(--ok);background:#d9eadf}.badge.grade{color:#1d4e89;background:#dce8f6}.card-badges{flex-wrap:wrap;gap:8px;display:flex}.work-head-meta{flex-direction:column;align-items:flex-end;gap:8px;display:flex}.grade-box{color:#1d4e89;background:#dce8f6;border-radius:14px;gap:6px;margin-bottom:20px;padding:16px 18px;display:grid}.grade-box p{margin:0}.grades-summary{grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:12px;margin-bottom:24px;display:grid}.grades-summary .grade-box{margin:0}.grades-summary strong{letter-spacing:-.03em;font-size:1.8rem}.grade-list{gap:12px;margin:0;padding:0;list-style:none;display:grid}.grade-row{justify-content:space-between;align-items:center;gap:20px;display:flex}.grade-row h2{margin:0 0 4px}.grade-row p{margin:0}.grade-mark{letter-spacing:-.04em;text-align:right;color:#1d4e89;min-width:3rem;font-size:2rem;line-height:1}.grades-table-wrap{background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow);border-radius:16px;overflow-x:auto}.grades-table{border-collapse:collapse;width:100%;min-width:640px}.grades-table th,.grades-table td{text-align:left;vertical-align:top;border-bottom:1px solid #efe8da;padding:12px 14px}.grades-table th{text-transform:uppercase;letter-spacing:.08em;color:var(--muted);background:#f7f1e6;font-size:.78rem}.grades-table tbody tr{cursor:pointer}.grades-table tbody tr:hover{background:#f3efe6}.grades-table.is-plain tbody tr,.grades-table.is-plain tbody tr:hover,.grades-table tbody tr.is-plain,.grades-table tbody tr.is-plain:hover{cursor:default;background:0 0}.grades-table tbody tr:last-child td{border-bottom:0}.grades-table.is-book{min-width:760px}.grades-table.is-book th:first-child,.grades-table.is-book td:first-child{z-index:1;background:#fff;position:sticky;left:0}.grades-table.is-book th:first-child{background:#f7f1e6}.table-col{text-align:left;white-space:normal;min-width:92px;color:inherit;background:0 0;border:0;gap:2px;padding:2px 4px;display:grid}.table-col strong{font-size:.86rem}.grade-input{text-align:center;width:3.2rem;padding:6px 8px}.lesson-title-input{text-transform:none;letter-spacing:0;margin-top:6px;padding:6px 8px;font-weight:500}.schedule-grid{gap:10px;margin:0 0 16px;display:grid}.schedule-grid .check{align-items:center;gap:10px;display:flex}.schedule-grid select{width:auto}.grade-form{border-top:1px solid #efe8da;gap:10px;margin-top:16px;padding-top:16px;display:grid}.progress{gap:8px;font-size:.9rem;display:grid}.bar{background:#efe8da;border-radius:99px;height:8px;overflow:hidden}.bar i{background:linear-gradient(90deg, var(--blue), var(--yellow));height:100%;display:block}.work-head{justify-content:space-between;align-items:start;gap:16px;margin-bottom:24px;display:flex}.back{margin-bottom:18px}.timer{z-index:5;color:#f4efe6;font-family:var(--mono);font-variant-numeric:tabular-nums;text-align:center;box-shadow:var(--shadow);background:#1b2430;border-radius:12px;margin-bottom:18px;padding:12px 16px;font-size:1.15rem;position:sticky;top:12px}.timer.warn{background:#a33b32}.task-switcher{gap:10px;margin-bottom:18px;display:grid}.task-switcher p{margin:0}.task-switcher-nums{flex-wrap:wrap;gap:8px;display:flex}.task-num{min-width:42px;height:42px;padding:0 10px}.task-num.is-filled:not(.is-current){color:var(--ok);background:#d9eadf;border-color:#c3ddd0}.task-num.is-current:hover:not(:disabled){background:var(--blue-dark)}.task-pager{justify-content:space-between;gap:12px;margin-top:16px;display:flex}.tasks{gap:18px;margin:0;padding:0;list-style:none;display:grid}.task{border-radius:16px;padding:20px}.statement{color:#f4efe6;white-space:pre-wrap;font-family:var(--mono);background:#1b2430;border-radius:12px;margin:0 0 16px;padding:14px;font-size:.92rem;overflow:auto}.python-editor{background:#1b2430;border-radius:12px;overflow:hidden}.python-editor:focus-within{outline:2px solid var(--blue)}.python-editor .cm-editor{outline:none}.python-editor .cm-scroller{font-family:var(--mono)}.python-view{color:#f4efe6;min-height:72px;max-height:360px;font-family:var(--mono);white-space:pre;background:#1b2430;border-radius:12px;margin:0;padding:14px 16px;font-size:.92rem;overflow:auto}.actions{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:12px;margin-top:20px;display:flex}.actions.is-inline{justify-content:flex-start;margin-top:0}.actions div{gap:10px;display:flex}.error,.ok{margin:0}.error{color:var(--err)}.danger{background:var(--err)}.danger:hover:not(:disabled){background:#822f28}.check{align-items:center;gap:8px;font-weight:600;display:flex}.check input{width:auto}.section-title{margin:32px 0 12px}.task-slot{gap:12px;margin-top:28px;display:grid}.import-help{margin-top:8px}.import-help summary{cursor:pointer;font-weight:600}.import-help p{margin:10px 0}.import-help code{font-family:var(--mono);font-size:.9em}.answer-block{gap:8px;margin-top:12px;display:grid}.task-images{gap:12px;margin:0 0 16px;display:grid}.task-image{gap:8px;margin:0;display:grid}.task-image img{object-fit:contain;background:#1b2430;border-radius:12px;width:100%;max-height:420px;display:block}.task-image button{width:fit-content}input[type=file]{padding:8px}.check-box{background:#efe8da;border-radius:12px;gap:8px;margin-top:12px;padding:12px 14px;display:grid}.check-box p{margin:0}.check-list{gap:10px;margin:0;padding:0;list-style:none;display:grid}.check-case{border-top:1px solid #e5dcc8;gap:8px;padding-top:8px;display:grid}.check-io{gap:4px;display:grid}.check-io pre{color:var(--ink);font-family:var(--mono);white-space:pre-wrap;word-break:break-word;background:#fff;border-radius:8px;margin:0;padding:8px 10px;font-size:.82rem}.tests-box{background:#f7f1e6;border-radius:12px;gap:12px;margin:16px 0 0;padding:14px;display:grid}.tests-box>summary,.test-case>summary,.check-case>summary{cursor:pointer;flex-wrap:wrap;align-items:baseline;gap:8px 12px;font-weight:600;list-style:none;display:flex}.tests-box>summary::-webkit-details-marker{display:none}.test-case>summary::-webkit-details-marker{display:none}.check-case>summary::-webkit-details-marker{display:none}.tests-box>summary:before,.test-case>summary:before,.check-case>summary:before{content:"▸";color:var(--muted);font-weight:700}.tests-box[open]>summary:before,.test-case[open]>summary:before,.check-case[open]>summary:before{content:"▾"}.tests-box h3,.test-case h3{margin:0;font-size:1rem}.test-case{border-bottom:1px solid #efe8da;gap:8px;padding-bottom:12px;display:grid}.test-io{gap:8px;display:grid}@media (width>=720px){.test-io{grid-template-columns:1fr 1fr}}.ok{color:var(--ok);font-weight:600}.visually-hidden{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.spinner-block{justify-items:center;gap:12px;padding:48px 16px;display:grid}.spinner-block p{margin:0}.spinner{border:3px solid #2b6ea32e;border-top-color:var(--blue);border-radius:50%;width:2rem;height:2rem;animation:.7s linear infinite spin}.spinner.is-inline{border-width:2px;border-color:#fff #ffffff59 #ffffff59;flex-shrink:0;width:.95rem;height:.95rem}.spinner.is-ink,button.ghost .spinner.is-inline,.grade-cell .spinner{border-color:#2b6ea338;border-top-color:var(--blue)}.grade-cell{align-items:center;gap:8px;display:inline-flex}@keyframes spin{to{transform:rotate(360deg)}}@media (width<=640px){h1{font-size:1.55rem}.topbar-main,.work-head,.actions,.admin-nav,.page-nav{flex-direction:column;align-items:stretch}.work-head-meta{align-items:flex-start}}