:root{
  --bg:#f4f7fb;--paper:#fff;--ink:#10213a;--muted:#66758c;--line:#dbe3ee;
  --navy:#17324d;--teal:#1f7a83;--teal2:#2a8f8e;--gold:#c7873f;--purple:#6659a8;
  --green:#16845b;--green-bg:#eaf8f2;--orange:#a56813;--orange-bg:#fff4dd;--red:#b04444;--red-bg:#fff0f0;
  --shadow:0 18px 55px rgba(15,35,55,.10);--radius:22px;
}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:linear-gradient(135deg,#f7f9fc,#eef4f6);color:var(--ink);font:15px/1.55 Inter,system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif}button,input,select,textarea{font:inherit}button{cursor:pointer}a{color:inherit}h1,h2,h3,h4,p{margin:0}svg{display:block}.hidden{display:none!important}
.app-shell{min-height:100vh}.topbar{position:sticky;top:0;z-index:30;background:rgba(255,255,255,.94);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}.topbar-inner{max-width:1260px;margin:auto;padding:11px 22px;display:flex;align-items:center;gap:12px}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-weight:850;letter-spacing:-.3px}.brand-mark{width:38px;height:38px;border-radius:12px;background:linear-gradient(135deg,var(--navy),var(--teal));display:grid;place-items:center;color:#fff}.brand-mark svg{width:21px;height:21px}.brand small{display:block;font-size:10px;color:var(--muted);font-weight:650;letter-spacing:.4px}.top-actions{margin-left:auto;display:flex;align-items:center;gap:8px}.user-chip{display:flex;align-items:center;gap:8px;padding:7px 10px;border-radius:12px;background:#f2f6fa;color:#33445d;font-size:12px}.user-chip strong{font-size:12px}.online-dot{width:7px;height:7px;border-radius:50%;background:var(--green)}
.container{max-width:1260px;margin:auto;padding:28px 22px 70px}.hero{border-radius:30px;overflow:hidden;background:linear-gradient(120deg,#17324d 10%,#20596a 55%,#237c7e);color:#fff;box-shadow:var(--shadow);position:relative}.hero:after{content:"";position:absolute;right:-80px;top:-140px;width:420px;height:420px;border-radius:50%;background:radial-gradient(circle,#ffffff18,transparent 64%)}.hero-content{padding:46px 46px 42px;position:relative;z-index:2}.eyebrow{text-transform:uppercase;font-size:12px;letter-spacing:1.4px;opacity:.8;font-weight:750}.hero h1{font-size:clamp(34px,5vw,68px);line-height:1.02;letter-spacing:-2.4px;margin:8px 0 14px}.hero p{font-size:clamp(15px,2vw,19px);opacity:.92;max-width:720px}.status-pill{display:inline-flex;align-items:center;gap:8px;margin-top:24px;padding:9px 13px;border-radius:999px;background:#fff;color:var(--green);font-weight:800;font-size:12px}.status-pill.warn{color:var(--orange);background:#fff6dd}.status-pill.error{color:var(--red);background:#fff0f0}
.grid{display:grid;gap:18px}.grid.two{grid-template-columns:repeat(2,minmax(0,1fr))}.grid.three{grid-template-columns:repeat(3,minmax(0,1fr))}.grid.four{grid-template-columns:repeat(4,minmax(0,1fr))}.card{background:var(--paper);border:1px solid var(--line);border-radius:20px;padding:22px;box-shadow:0 5px 20px rgba(22,42,68,.04)}.card.hover{transition:.2s transform,.2s box-shadow,.2s border-color}.card.hover:hover{transform:translateY(-2px);box-shadow:0 12px 30px rgba(22,42,68,.09);border-color:#c7d5e2}.card h3{font-size:18px;margin-bottom:7px}.card p{color:var(--muted)}.section{margin-top:26px}.section-head{display:flex;align-items:flex-end;gap:12px;margin-bottom:14px}.section-head h2{font-size:25px;letter-spacing:-.8px}.section-head p{color:var(--muted);font-size:13px}.section-head .spacer{flex:1}.iconbox{width:43px;height:43px;border-radius:13px;display:grid;place-items:center;background:#ecf5f5;color:var(--teal);flex-shrink:0}.iconbox.gold{background:#fff4e8;color:#b67127}.iconbox.purple{background:#f2efff;color:var(--purple)}.iconbox svg{width:23px;height:23px}.feature-card{display:flex;gap:15px;align-items:flex-start;text-decoration:none}.feature-card .arrow{margin-left:auto;color:#91a0b2}.feature-card .meta{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px}.tag{font-size:10px;font-weight:800;padding:4px 7px;border-radius:7px;background:#eef2f7;color:#64748b;text-transform:uppercase;letter-spacing:.4px}.tag.teal{background:#e8f6f5;color:#17736f}.tag.gold{background:#fff3e4;color:#9a611d}.tag.green{background:var(--green-bg);color:var(--green)}
.btn{border:1px solid var(--line);background:#fff;color:var(--ink);min-height:42px;padding:9px 14px;border-radius:11px;display:inline-flex;align-items:center;justify-content:center;gap:8px;font-weight:760;font-size:13px;text-decoration:none}.btn:hover{background:#f7f9fc}.btn.primary{background:linear-gradient(135deg,var(--navy),#244f6b);color:#fff;border-color:transparent}.btn.teal{background:var(--teal);color:#fff;border-color:var(--teal)}.btn.gold{background:var(--gold);color:#fff;border-color:var(--gold)}.btn.danger{color:var(--red);border-color:#efc9c9;background:#fff7f7}.btn.small{min-height:34px;padding:6px 9px;font-size:11px;border-radius:9px}.btn:disabled{opacity:.48;cursor:not-allowed}.btn svg{width:17px;height:17px}.link-btn{border:0;background:none;color:var(--teal);font-weight:750;padding:3px}.spacer{flex:1}
.form{display:grid;gap:14px}.form-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}.field{display:grid;gap:6px}.field label{font-size:11px;font-weight:800;color:#57677e;letter-spacing:.3px}.field input,.field select,.field textarea{width:100%;border:1px solid #ced8e5;background:#fff;color:var(--ink);border-radius:10px;min-height:43px;padding:9px 11px;outline:none}.field textarea{min-height:110px;resize:vertical}.field input:focus,.field select:focus,.field textarea:focus{border-color:#7aa5ac;box-shadow:0 0 0 3px #2a8f8e1a}.help{font-size:11px;color:var(--muted)}.panel{background:#fff;border:1px solid var(--line);border-radius:20px;overflow:hidden}.panel-head{padding:18px 20px;border-bottom:1px solid var(--line);display:flex;gap:10px;align-items:center}.panel-head h3{font-size:17px}.panel-body{padding:20px}.tabs{display:flex;gap:5px;flex-wrap:wrap;padding:6px;background:#eef2f6;border-radius:12px}.tab{padding:8px 11px;border:0;background:transparent;border-radius:9px;font-weight:760;color:#65748a}.tab.active{background:#fff;color:var(--ink);box-shadow:0 2px 8px #1232}.table-wrap{overflow:auto;border:1px solid var(--line);border-radius:13px}.table{width:100%;border-collapse:collapse;min-width:650px}.table th,.table td{text-align:left;padding:11px 12px;border-bottom:1px solid #e6ebf2;font-size:12px}.table th{background:#f6f8fb;color:#607086;text-transform:uppercase;letter-spacing:.4px;font-size:10px}.table tr:last-child td{border-bottom:0}.empty{padding:30px;text-align:center;color:var(--muted)}
.auth-wrap{max-width:470px;margin:42px auto}.auth-brand{text-align:center;margin-bottom:18px}.auth-brand .brand-mark{margin:0 auto 10px;width:54px;height:54px;border-radius:17px}.auth-brand h1{font-size:27px}.switcher{display:grid;grid-template-columns:1fr 1fr;gap:5px;background:#eef2f6;padding:5px;border-radius:12px;margin-bottom:18px}.switcher button{border:0;background:transparent;border-radius:9px;padding:9px;font-weight:800;color:#607086}.switcher button.active{background:#fff;color:var(--ink);box-shadow:0 2px 8px #1232}.notice{padding:12px 13px;border-radius:11px;font-size:12px;margin-bottom:12px;background:#eef5fb;color:#40617c;border:1px solid #d9e8f4}.notice.good{background:var(--green-bg);color:var(--green);border-color:#c7eadc}.notice.warn{background:var(--orange-bg);color:#8a5b12;border-color:#f0d8a7}.notice.bad{background:var(--red-bg);color:var(--red);border-color:#f0caca}
.dash-hero{display:flex;align-items:center;gap:18px;background:#fff;border:1px solid var(--line);border-radius:22px;padding:22px}.dash-hero h1{font-size:27px;letter-spacing:-.8px}.dash-hero p{color:var(--muted)}.stat-card strong{display:block;font-size:30px;letter-spacing:-1px}.stat-card span{font-size:11px;color:var(--muted);font-weight:700}.progress{height:8px;background:#e9eef4;border-radius:10px;overflow:hidden}.progress>span{display:block;height:100%;background:linear-gradient(90deg,var(--teal),#48a4a0);border-radius:10px}.progress-line{display:flex;align-items:center;gap:10px}.progress-line .progress{flex:1}.progress-line strong{font-size:12px;min-width:42px;text-align:right}
.course-layout{display:grid;grid-template-columns:240px minmax(0,1fr);gap:18px}.course-card{min-height:190px;display:flex;flex-direction:column}.course-card .top{display:flex;gap:13px}.course-card .course-meta{margin-top:auto;padding-top:16px}.lesson-nav{display:grid;gap:8px}.lesson-link{display:flex;align-items:center;gap:10px;padding:11px;border:1px solid var(--line);border-radius:11px;background:#fff}.lesson-link.done{border-color:#bfe1d4;background:#f1faf6}.lesson-link.active{border-color:#a8c9ce;background:#eef8f8}.lesson-num{width:28px;height:28px;border-radius:9px;background:#eef2f7;display:grid;place-items:center;font-size:11px;font-weight:850}.lesson-body{display:grid;gap:16px}.lesson-block{border:1px solid var(--line);border-radius:15px;padding:17px;background:#fff}.lesson-block.lead{font-size:16px;line-height:1.75;background:linear-gradient(135deg,#f7fbfb,#fff)}.lesson-block.note{border-left:4px solid var(--gold);background:#fff9f1}.lesson-block.formula{font:700 19px/1.5 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;text-align:center;background:#f5f7fb}.lesson-block pre{margin:0;white-space:pre-wrap;font:13px/1.7 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}.memory-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}.memory-cell{border:1px solid var(--line);border-radius:11px;padding:12px;text-align:center}.memory-cell strong{display:block;font-size:17px}.memory-cell small{color:var(--muted)}.quiz{border:1px solid #cfe3e3;border-radius:16px;padding:17px;background:#f5fbfb}.quiz h4{margin-bottom:11px}.quiz-options{display:grid;gap:7px}.quiz-option{border:1px solid #d5e0e8;background:#fff;border-radius:10px;padding:10px 12px;text-align:left}.quiz-option.selected{border-color:var(--teal);background:#eaf7f6}.quiz-option.correct{border-color:#7cc6a9;background:#ecf9f3}.quiz-option.wrong{border-color:#e4aaaa;background:#fff1f1}.feedback{font-size:12px;margin-top:9px;font-weight:700}
.exercise-layout{display:grid;grid-template-columns:230px minmax(0,1fr);gap:18px}.exercise-side{position:sticky;top:80px;align-self:start}.exercise-side .card{padding:15px}.exercise-list{display:grid;grid-template-columns:repeat(5,1fr);gap:6px;margin-top:10px}.ex-num{border:1px solid var(--line);background:#fff;border-radius:8px;min-height:34px;font-size:11px}.ex-num.active{background:var(--navy);color:#fff}.ex-num.done{border-color:#9fd8c2;background:#edf9f4;color:var(--green)}.exercise-main .card{padding:0;overflow:hidden}.ex-head{padding:23px;background:linear-gradient(135deg,#fff,#f1f8f8);border-bottom:1px solid var(--line)}.ex-head h2{font-size:23px}.ex-head p{color:var(--muted);margin-top:7px;white-space:pre-wrap}.ex-body{padding:22px}.question{padding:18px 0;border-bottom:1px solid #e9eef4}.question:first-child{padding-top:0}.question:last-child{border-bottom:0}.q-title{display:flex;gap:9px;align-items:flex-start;margin-bottom:12px}.q-index{width:27px;height:27px;flex:0 0 27px;border-radius:9px;background:#eaf5f5;color:var(--teal);display:grid;place-items:center;font-size:11px;font-weight:850}.q-prompt{font-weight:720;white-space:pre-wrap}.choices{display:grid;gap:8px}.choice{border:1px solid var(--line);border-radius:11px;padding:10px 12px;background:#fff;display:flex;align-items:center;gap:9px}.choice:has(input:checked){border-color:#83b7bd;background:#eef8f8}.choice input{accent-color:var(--teal)}.answer-input{width:100%;max-width:520px;border:1px solid #ccd8e4;border-radius:10px;padding:10px;min-height:42px}.match-grid{display:grid;gap:8px}.match-row{display:grid;grid-template-columns:1fr 1fr;gap:10px;align-items:center}.match-row select{border:1px solid #ccd8e4;border-radius:9px;padding:9px}.order-list{display:grid;gap:7px}.order-item{display:flex;gap:8px;align-items:center;padding:9px;border:1px solid var(--line);border-radius:10px;background:#fff}.order-item code{flex:1;white-space:pre-wrap}.order-handle{cursor:grab;color:#8795a8}.char-strip{display:flex;gap:6px;flex-wrap:wrap}.char-btn{min-width:42px;min-height:54px;border:1px solid var(--line);border-radius:9px;background:#fff}.char-btn.active{background:#dff3f0;border-color:#69aea8}.char-btn small{display:block;color:var(--muted)}.grid-answer{width:100%;border-collapse:collapse}.grid-answer th,.grid-answer td{border:1px solid var(--line);padding:7px}.grid-answer input,.grid-answer select{width:100%;border:1px solid #ccd8e4;border-radius:7px;padding:7px}.q-actions{display:flex;gap:8px;align-items:center;margin-top:11px}.q-result{font-size:11px;font-weight:800}.q-result.good{color:var(--green)}.q-result.bad{color:var(--red)}.hint{margin-top:9px;padding:9px 11px;border-radius:9px;background:#fff7e7;color:#855811;font-size:11px}.ex-nav{display:flex;gap:8px;padding:16px 22px;border-top:1px solid var(--line);background:#fafbfc}.autosave-note{font-size:10px;color:var(--muted);margin-left:auto;align-self:center}
.exam-shell{max-width:980px;margin:auto}.exam-header{position:sticky;top:62px;z-index:20;background:#fff;border:1px solid var(--line);border-radius:16px;padding:13px 16px;display:flex;align-items:center;gap:12px;box-shadow:0 5px 20px #1231}.timer{font:800 18px ui-monospace,monospace;color:var(--navy)}.timer.danger{color:var(--red)}.exam-progress{flex:1}.exam-question{background:#fff;border:1px solid var(--line);border-radius:18px;padding:20px;margin-top:14px}.exam-question h3{font-size:16px;margin-bottom:12px}.points{font-size:10px;color:var(--muted);font-weight:800}.exam-footer{display:flex;justify-content:space-between;gap:12px;margin-top:18px}.save-state{font-size:11px;color:var(--muted)}
.modal-backdrop{position:fixed;inset:0;background:#0f2033aa;z-index:80;display:grid;place-items:center;padding:18px}.modal{width:min(720px,100%);max-height:90vh;overflow:auto;background:#fff;border-radius:20px;box-shadow:0 30px 80px #0005}.modal-head{padding:18px 20px;border-bottom:1px solid var(--line);display:flex;align-items:center;gap:10px;position:sticky;top:0;background:#fff;z-index:2}.modal-body{padding:20px}.toast{position:fixed;right:18px;bottom:18px;z-index:100;background:#17324d;color:#fff;padding:11px 14px;border-radius:11px;box-shadow:0 15px 40px #0004;font-size:12px;max-width:360px}.toast.bad{background:#9c3f3f}.toast.good{background:#137557}
.print-area{display:none}@media print{body{background:#fff}.topbar,.no-print{display:none!important}.container{max-width:none;padding:0}.card,.panel{box-shadow:none}.print-area{display:block}.screen-only{display:none!important}@page{size:A4;margin:10mm}}
@media(max-width:900px){.course-layout{grid-template-columns:1fr}.course-layout>aside{position:static!important}.grid.four{grid-template-columns:repeat(2,1fr)}.grid.three{grid-template-columns:1fr 1fr}.exercise-layout{grid-template-columns:1fr}.exercise-side{position:static}.exercise-list{grid-template-columns:repeat(10,1fr)}}
@media(max-width:640px){.container{padding:18px 13px 60px}.topbar-inner{padding:9px 12px}.brand span.name{display:none}.user-chip span{display:none}.hero-content{padding:30px 22px}.hero h1{font-size:40px}.grid.two,.grid.three,.grid.four{grid-template-columns:1fr}.form-row{grid-template-columns:1fr}.dash-hero{align-items:flex-start}.memory-grid{grid-template-columns:1fr}.match-row{grid-template-columns:1fr}.exercise-list{grid-template-columns:repeat(7,1fr)}.ex-head,.ex-body{padding:17px}.exam-header{top:56px;flex-wrap:wrap}.exam-progress{order:3;flex-basis:100%}}