:root{
 --brand-blue:#3457F0;--brand-blue-hover:#2641C9;--brand-blue-50:#EAF0FE;--brand-blue-200:#C9D5FC;
 --brand-night:#0B1220;--brand-night-2:#131C30;--brand-amber:#F07A2A;--brand-amber-50:#FFF1E6;
 --ink:#0F172A;--ink-2:#4A546B;--ink-3:#7C869C;--mist:#F4F6FB;--line:#E1E6F0;--paper:#fff;
 --done:#17915A;--done-bg:#E4F5EC;--review:#6E4FE8;--review-bg:#EFEBFE;--returned:#B8520F;--returned-bg:#FFF1E6;
 --failed:#D23B3B;--failed-bg:#FCEBEB;--idle:#5E677D;--idle-bg:#F0F2F6;
 --font:"Onest",system-ui,-apple-system,"Segoe UI",sans-serif;--mono:"JetBrains Mono",ui-monospace,monospace;
 --sp1:4px;--sp2:8px;--sp3:12px;--sp4:16px;--sp6:24px;--sp8:32px;--sp12:48px;--sp16:64px;
 --r-field:8px;--r-btn:12px;--r-card:16px;--shadow:0 10px 30px rgba(15,23,42,.06)
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--mist);color:var(--ink);font-family:var(--font)}
button,input,textarea{font:inherit}
button{cursor:pointer}
.mono{font-family:var(--mono);font-variant-numeric:tabular-nums}
.muted{color:var(--ink-2)}
.eyebrow{font-size:12px;line-height:1.3;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-3)}
.eyebrow.light{color:#9EABC3}
h1{font-size:36px;line-height:1.1;margin:8px 0 12px;font-weight:800;letter-spacing:-.025em}
h2{font-size:24px;line-height:1.25;margin:0 0 12px;font-weight:700}
h3{font-size:18px;line-height:1.35;margin:0 0 8px}
p{line-height:1.6}
.sub{font-size:18px;color:var(--ink-2);max-width:760px;margin:0}
.login{min-height:100vh;background:var(--brand-night);display:grid;place-items:center;padding:24px;position:relative;overflow:hidden}

.login-card{position:relative;width:min(540px,100%);padding:48px;background:var(--brand-night-2);border:1px solid #27334b;border-radius:16px;color:#fff;box-shadow:0 28px 80px rgba(0,0,0,.3)}
.login h1{font-size:44px}
.login-lead{font-size:18px;color:#B8C2D5;margin:0;max-width:460px}
.role-grid{display:grid;grid-template-columns:1fr;gap:10px;margin-top:32px}
.role-btn{min-height:82px;background:#17223A;color:#fff;border:1px solid #2D3A54;border-radius:12px;padding:16px 18px;text-align:left;display:grid;grid-template-columns:44px 1fr;grid-template-rows:auto auto;column-gap:10px}
.role-btn:hover{border-color:#6076e8;transform:translateY(-1px)}
.role-kicker{grid-row:1/3;color:#91A2FF;font:600 13px var(--mono);padding-top:3px}
.role-btn strong{font-size:17px}.role-btn small{color:#AAB6CA;margin-top:2px}.login-note{font-size:12px;color:#7F8CA5;margin-top:24px}
.shell{min-height:100vh}.topbar{height:72px;background:var(--paper);border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 32px;position:sticky;top:0;z-index:20}
.brand-lockup{display:flex;align-items:center;gap:10px;font-weight:800}.brand-mark{width:32px;height:32px;border-radius:9px;background:var(--brand-blue);color:#fff;display:grid;place-items:center}
.top-actions{display:flex;align-items:center;gap:12px}.who{font-size:14px;color:var(--ink-2)}.avatar{width:38px;height:38px;border-radius:50%;background:var(--brand-blue-50);color:var(--brand-blue);display:grid;place-items:center;font-weight:700}
.layout{display:grid;grid-template-columns:240px 1fr}.side{min-height:calc(100vh - 72px);background:#fff;border-right:1px solid var(--line);padding:24px 16px;display:flex;flex-direction:column}.side-label{font-size:12px;color:var(--ink-3);font-weight:700;text-transform:uppercase;letter-spacing:.08em;padding:0 12px 12px}.nav{display:grid;gap:4px}.nav-item{height:44px;border:0;background:transparent;color:var(--ink-2);border-radius:10px;padding:0 12px;display:flex;align-items:center;justify-content:space-between;text-align:left}.nav-item:hover,.nav-item.active{background:var(--brand-blue-50);color:var(--brand-blue);font-weight:600}.nav-item em{font:600 11px var(--mono);background:var(--brand-amber-50);color:var(--returned);padding:3px 6px;border-radius:999px;font-style:normal}.side-bottom{margin-top:auto;padding:20px 12px 0;border-top:1px solid var(--line);display:flex;justify-content:space-between;color:var(--ink-3);font-size:12px}
.main{max-width:1320px;width:100%;margin:0 auto;padding:40px 32px 80px}.page-head{margin-bottom:24px}.page-head h1{margin-bottom:8px}
.btn{height:40px;border:1px solid var(--line);border-radius:12px;background:#fff;color:var(--ink);padding:0 15px;font-weight:600;display:inline-flex;align-items:center;justify-content:center;gap:7px}.btn:hover{border-color:#B9C2D3}.btn.primary{background:var(--brand-blue);border-color:var(--brand-blue);color:#fff}.btn.primary:hover{background:var(--brand-blue-hover)}.btn.ghost{background:var(--brand-blue-50);border-color:transparent;color:var(--brand-blue)}.btn.small{height:36px;padding:0 12px;font-size:13px}.student .btn{height:56px;border-radius:14px;font-size:18px}.full{width:100%}
.grid{display:grid;gap:16px}.grid-3{grid-template-columns:repeat(3,1fr)}.grid-2{grid-template-columns:repeat(2,1fr)}.section{margin-top:32px}.section-head{display:flex;align-items:center;justify-content:space-between;margin-bottom:14px}.link-btn{border:0;background:transparent;color:var(--brand-blue);font-weight:600}
.card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:24px;box-shadow:0 2px 8px rgba(15,23,42,.025)}
.next-card{background:var(--brand-night);color:#fff;border-radius:16px;padding:32px;display:flex;align-items:center;justify-content:space-between;gap:28px;margin:24px 0}.next-copy{max-width:760px}.next-card h2{font-size:30px;margin:8px 0}.next-card p{color:#B4C0D5;margin:0 0 22px}.next-card small{display:block;color:#9EABC3;margin-top:10px}.next-progress{height:8px;background:#2A3449;border-radius:99px;overflow:hidden;max-width:540px}.next-progress span{display:block;height:100%;background:var(--brand-blue);border-radius:inherit}.light-primary{background:#fff;color:var(--brand-blue);border-color:#fff;min-width:190px}.metric-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:24px}.metric-card strong{display:block;font-size:28px;margin:10px 0 4px}.metric-card p{margin:0;color:var(--ink-2);font-size:16px}
.course-card{display:flex;flex-direction:column;min-height:290px}.card-top{display:flex;align-items:center;justify-content:space-between}.tag{display:inline-flex;align-items:center;padding:6px 9px;border-radius:8px;background:var(--brand-blue-50);color:var(--brand-blue);font-size:12px;font-weight:700}.progress-row{display:grid;grid-template-columns:1fr auto;align-items:center;gap:10px;margin-top:auto}.progress{height:8px;background:#EDF0F5;border-radius:99px;overflow:hidden}.progress i{display:block;height:100%;background:var(--brand-blue);border-radius:inherit}.progress-row .mono{font-size:12px}.course-meta{display:flex;gap:16px;color:var(--ink-3);font-size:13px}.course-head{display:flex;align-items:flex-start;justify-content:space-between;gap:24px}.course-intro{flex:1}.passport{display:flex;gap:10px;flex-wrap:wrap;margin-top:24px}.passport span{background:#fff;border:1px solid var(--line);border-radius:12px;padding:12px 14px;color:var(--ink-2);font-size:13px}.passport b{display:block;color:var(--ink);margin-bottom:4px}.progress-card{width:250px;flex:none}.progress-card strong{display:block;font-size:30px;margin:8px 0}.progress-card .mono{display:block;margin-top:8px;font-size:12px}.progress-card .btn{margin-top:18px}
.back{margin-bottom:20px}.module{margin-top:32px}.module-head{display:flex;justify-content:space-between;align-items:end;margin-bottom:12px}.module-head h2{margin:4px 0 0}.steps{display:grid;gap:8px}.step{width:100%;border:1px solid var(--line);background:#fff;border-radius:12px;padding:12px;display:grid;grid-template-columns:40px 1fr auto;gap:12px;align-items:center;text-align:left;color:var(--ink)}.step:hover{border-color:#BFC9DC}.step.current{border:2px solid var(--brand-blue);box-shadow:0 0 0 4px var(--brand-blue-50)}.step-icon{width:40px;height:40px;border-radius:9px;background:var(--brand-blue-50);color:var(--brand-blue);display:grid;place-items:center;font-weight:700}.step-copy b{display:block;font-size:15px}.step-copy small{display:block;color:var(--ink-2);margin-top:3px}.status{display:inline-flex;align-items:center;gap:6px;font-size:12px;font-weight:700;white-space:nowrap}.status b{width:20px;height:20px;border-radius:50%;display:grid;place-items:center;font-size:12px}.status small{display:block;color:var(--ink-3);font-weight:400}.status.done{color:var(--done)}.status.done b{background:var(--done-bg)}.status.review{color:var(--review)}.status.review b{background:var(--review-bg)}.status.returned{color:var(--returned)}.status.returned b{background:var(--returned-bg)}.status.failed{color:var(--failed)}.status.failed b{background:var(--failed-bg)}.status.idle{color:var(--idle)}.status.idle b{background:var(--idle-bg)}
.step-layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:24px}.step-main{background:#fff;border:1px solid var(--line);border-radius:16px;padding:32px}.step-top,.answer-row,.review-work-head{display:flex;justify-content:space-between;align-items:center;gap:12px}.step-main h1{font-size:32px;margin-top:16px}.step-content{font-size:18px;line-height:1.7}.step-content p{white-space:pre-line}.source{font:13px/1.7 var(--mono);background:var(--brand-night);color:#DCE3F2;padding:16px;border-radius:12px;overflow:auto;white-space:pre-wrap}.answer-block{margin-top:28px;padding-top:24px;border-top:1px solid var(--line)}.answer-label{font-size:13px;font-weight:700;color:var(--ink-2);margin-bottom:10px}.option{display:flex;align-items:flex-start;gap:10px;padding:13px;border:1px solid var(--line);border-radius:10px;margin:8px 0}.option:has(input:checked){background:var(--brand-blue-50);border-color:var(--brand-blue-200)}.field{width:100%;border:1px solid var(--line);border-radius:8px;padding:12px 13px;background:#fff;outline:0;margin:6px 0 14px}.field:focus{border-color:var(--brand-blue);box-shadow:0 0 0 3px var(--brand-blue-50)}textarea.field{resize:vertical}.code-editor{width:100%;min-height:280px;border:1px solid #26324A;background:var(--brand-night);color:#E8EDF7;border-radius:12px;padding:18px;font:13px/1.6 var(--mono);resize:vertical;outline:0}.file-drop{border:1px dashed #B9C2D3;padding:20px;text-align:center;border-radius:10px;color:var(--ink-2);margin-top:4px}.file-drop small{display:block;color:var(--ink-3);margin-top:4px}.judge-note{font-size:12px;color:var(--ink-3);margin-top:8px}.step-actions{margin-top:28px}.submit-btn{min-width:210px}.success-box,.review-box,.return-box{padding:14px 16px;border-radius:10px;font-weight:700}.success-box{background:var(--done-bg);color:var(--done)}.review-box{background:var(--review-bg);color:var(--review)}.return-box{background:var(--returned-bg);color:var(--returned)}.success-box small,.review-box small,.return-box small{display:block;font-weight:400;margin-top:4px}.step-aside{display:grid;gap:16px;align-content:start}.step-aside dl{margin:16px 0 0}.step-aside dl div{padding:12px 0;border-top:1px solid var(--line)}.step-aside dt{font-size:12px;color:var(--ink-3);margin-bottom:4px}.step-aside dd{margin:0;font-size:14px}.warning-card{background:var(--brand-amber-50);border-color:#F6D1B5;color:var(--returned)}
.rating-layout{display:grid;grid-template-columns:260px 1fr;gap:16px}.rating-total strong{font-size:64px;line-height:1;display:block;margin:18px 0 0}.rank-line{margin-top:24px;padding-top:16px;border-top:1px solid var(--line);display:flex;flex-direction:column;gap:3px}.breakdown{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:16px}.breakdown div{border:1px solid var(--line);border-radius:10px;padding:16px}.breakdown b{font:600 24px var(--mono);display:block}.breakdown span{display:block;color:var(--ink-2);font-size:13px;margin-top:5px}.notice{background:var(--brand-blue-50);color:var(--brand-blue);padding:14px 16px;border-radius:10px;margin-top:16px;font-size:14px}
.queue-summary{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:24px 0}.queue-summary>div{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px}.queue-summary b{font:600 24px var(--mono);display:block}.queue-summary span{color:var(--ink-2);font-size:13px}.table-wrap{overflow:auto}.table{width:100%;border-collapse:collapse;background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden}.table th,.table td{text-align:left;padding:13px 14px;border-bottom:1px solid var(--line);font-size:14px;vertical-align:middle}.table th{background:var(--mist);color:var(--ink-2);font-weight:600}.table tr:last-child td{border-bottom:0}.table td small{display:block;color:var(--ink-3);margin-top:3px}.signal{display:inline-flex;align-items:center;gap:6px;font-size:12px;font-weight:700}.signal b{width:20px;height:20px;border-radius:50%;display:grid;place-items:center}.signal.danger{color:var(--failed)}.signal.danger b{background:var(--failed-bg)}.signal.warn{color:var(--returned)}.signal.warn b{background:var(--returned-bg)}.signal.ok{color:var(--done)}.signal.ok b{background:var(--done-bg)}.mini-progress{width:110px;height:6px;background:#EDF0F5;border-radius:99px;overflow:hidden}.mini-progress span{display:block;height:100%;background:var(--brand-blue)}
.review-layout{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:16px}.submission-preview{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:18px 0}.fake-link,.fake-shot{border:1px dashed #C1C9D8;border-radius:10px;padding:18px;background:var(--mist);font-size:13px}.fake-shot{min-height:150px;display:grid;place-items:center;color:var(--ink-3)}.criteria{padding-left:22px;line-height:1.6}.criteria li{padding:5px 0}.actions{display:flex;gap:8px;flex-wrap:wrap;margin-top:16px}.actions.vertical{display:grid}.question-meta{display:flex;justify-content:space-between;color:var(--ink-2);font-size:13px}.question-card h3{margin-top:18px}
.admin-toolbar{display:flex;align-items:center;justify-content:space-between}.admin-course{min-height:360px}.pub,.draft{font-size:12px;font-weight:700}.pub{color:var(--done)}.draft{color:var(--ink-3)}.course-tree{margin:16px 0;display:grid;gap:6px}.course-tree div{display:flex;justify-content:space-between;background:var(--mist);border-radius:8px;padding:8px 10px;font-size:12px}.course-tree span{font:600 12px var(--mono);color:var(--ink-3)}.editor-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.editor-grid label{display:block;font-size:13px;font-weight:600;margin:16px 0}.admin-module{border:1px solid var(--line);border-radius:10px;padding:13px;margin:8px 0}.admin-module small{display:block;color:var(--ink-3);margin-top:4px}.admin-module .mono{display:block;margin-top:10px;font-size:11px;color:var(--ink-3);line-height:1.7}.empty{padding:24px;text-align:center;color:var(--ink-3);border:1px dashed #C3CBD9;border-radius:10px}.type-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}.type-card{display:flex;align-items:center;gap:12px;background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px}.type-card small{display:block;color:var(--ink-3);margin-top:3px}.type-card.dashed{border-style:dashed}
.toast{position:fixed;right:24px;bottom:24px;background:var(--brand-night);color:#fff;padding:13px 16px;border-radius:10px;box-shadow:0 14px 40px rgba(0,0,0,.2);z-index:50;font-size:14px}
.staff .main{font-size:15px}.staff .table th,.staff .table td{font-size:14px}.student .main{font-size:18px}.student .muted{font-size:16px}
@media(max-width:1000px){.layout{grid-template-columns:1fr}.side{min-height:auto;border-right:0;border-bottom:1px solid var(--line)}.nav{grid-template-columns:repeat(3,1fr)}.side-bottom{display:none}.grid-3,.type-grid{grid-template-columns:1fr 1fr}.course-head,.step-layout,.review-layout,.editor-grid,.rating-layout{grid-template-columns:1fr;display:grid}.progress-card{width:auto}.next-card{align-items:flex-start;flex-direction:column}}
@media(max-width:680px){.topbar{padding:0 16px}.who{display:none}.main{padding:28px 16px 60px}h1{font-size:30px}.login-card{padding:32px}.login h1{font-size:36px}.nav{grid-template-columns:1fr}.grid-3,.grid-2,.type-grid,.breakdown{grid-template-columns:1fr}.queue-summary{grid-template-columns:1fr}.submission-preview{grid-template-columns:1fr}.step{grid-template-columns:40px 1fr}.step>.status{grid-column:2}.next-card{padding:24px}.next-card h2{font-size:26px}.top-actions .btn{display:none}}
.btn.danger{color:#b42318;border-color:#f3c1bd;background:#fff7f6}.btn.danger:hover{background:#feeceb}.question-box{margin-top:20px;padding:16px;border:1px solid #dfe5ec;border-radius:12px;display:flex;justify-content:space-between;align-items:center;gap:16px;background:#fbfcfe}.question-box small{display:block;color:#667085;margin-top:4px}.feedback-thread{margin-top:16px;padding:16px;border-left:3px solid #356ae6;background:#f7f9fc;border-radius:8px}.feedback-thread .answer{margin-top:12px;padding:12px;background:white;border-radius:8px}.answer{margin-top:12px;padding:12px;background:#f5f7fa;border-radius:8px}.fake-link{display:block;padding:12px;background:#f5f7fa;border-radius:8px;color:#2457c5;text-decoration:underline;word-break:break-all}.fake-shot{margin-top:10px}.top-actions .btn{margin-left:8px}

.real-link{display:block;border:1px solid var(--brand-blue-200);background:var(--brand-blue-50);color:var(--brand-blue);border-radius:10px;padding:16px;font-weight:700;text-decoration:none;word-break:break-all}.real-link small{display:block;margin-top:8px;font-weight:400}.answer-thread{margin-top:14px;padding:14px;border-left:3px solid var(--brand-blue);background:var(--mist);border-radius:8px}.answer-thread p{margin-bottom:0}.question-box{flex-direction:column;align-items:stretch}.question-box .btn{align-self:flex-start}

.auth-tabs{display:grid;grid-template-columns:1fr 1fr;border-bottom:1px solid #2D3A54;margin-top:24px}.auth-tabs button{background:transparent;color:#AAB6CA;border:0;padding:12px;font-weight:700}.auth-tabs button.active{color:#fff;border-bottom:2px solid #91A2FF}.auth-form{margin-top:20px}.login .field{background:#101A2C;border-color:#34415A;color:#fff}.login .field::placeholder{color:#687690}.login label{display:block;color:#DCE3F2;font-size:13px;font-weight:600;margin:12px 0}.auth-submit{margin-top:8px}.auth-hint{font-size:12px;color:#8D9AB0}.demo-credentials{display:grid;gap:5px;margin-top:16px;padding:12px;border:1px solid #2D3A54;border-radius:10px;color:#9EABC3;font-size:12px}.demo-credentials code{color:#fff}.admin-module-head{display:flex;justify-content:space-between;align-items:flex-start;gap:12px}.admin-step{display:grid;grid-template-columns:40px 1fr auto;gap:10px;align-items:center;border-top:1px solid var(--line);padding:10px 0}.admin-step small{display:block;color:var(--ink-3);margin-top:3px}.modal-backdrop{position:fixed;inset:0;background:rgba(11,18,32,.55);display:grid;place-items:center;padding:20px;z-index:100}.modal-card{width:min(560px,100%);max-height:90vh;overflow:auto;background:#fff;border-radius:16px;padding:24px;box-shadow:0 24px 80px rgba(0,0,0,.25)}.modal-card label{display:block;font-size:13px;font-weight:700;margin:14px 0}.type-add{font:inherit;text-align:left;cursor:pointer}.type-add:hover{border-color:var(--brand-blue);background:var(--brand-blue-50)}