:root{--lumos-orange: #ff450b;--lumos-orange-button: #fe6519;--lumos-orange-dark: #cb4401;--lumos-orange-medium: #ff8142;--lumos-orange-light: #ffb581;--lumos-orange-faint: #ffefe0;--lumos-black: #191919;--lumos-black-deep: #121013;--lumos-card-dark: #1f1c21;--lumos-card-medium: #28262b;--lumos-charcoal: #2a2a2d;--lumos-text: #191919;--lumos-text-muted: #3c4154;--lumos-text-on-dark: #d0d0d0;--lumos-icon-gray: #8a95a8;--lumos-border: #d3d6de;--lumos-border-subtle: #e6e8ec;--lumos-border-on-dark: rgba(255, 255, 255, .08);--lumos-white: #ffffff;--lumos-nav-bg: #f4f5f7;--lumos-surface: #fbfaf8;--lumos-surface-alt: #f9fafa;--lumos-beige: #f9f4f1;--lumos-tan-border: #f4f0eb;--lumos-green: #5ee3a3;--lumos-green-bg: rgba(24, 154, 96, .12);--lumos-green-text: #0f7a48;--lumos-pink: #ff7dc0;--lumos-purple: #9747ff;--lumos-red: #ce3e1e;--lumos-red-bg: #ffeaeb;--lumos-tomato: #fa6446;--lumos-yellow-bg: #fff8e1;--lumos-yellow-border: #ffe7bf;--lumos-blue: #1378d1;--radius: 1.25rem;--radius-sm: .625rem;--radius-pill: 999px;--h0: 3.5rem;--h1: 2.5rem;--h2: 2rem;--h3: 1.625rem;--h4: 1.375rem;--h5: 1.125rem;--h6: 1rem;--p1: 1.125rem;--p2: 1rem;--p3: .9375rem;--p4: .8125rem;--eyebrow: .75rem;--font-sans: "Roobert", "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;--font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;--shadow-sm: 0 1px 2px rgba(25, 25, 25, .06);--shadow: 0 2px 8px rgba(25, 25, 25, .06), 0 1px 2px rgba(25, 25, 25, .04);--shadow-lg: 0 12px 32px rgba(25, 25, 25, .1), 0 2px 8px rgba(25, 25, 25, .05);--transition: .14s cubic-bezier(.4, 0, .2, 1)}@media (min-width: 1200px){:root{--h0: 5rem;--h1: 3rem;--h2: 2.25rem;--h3: 1.875rem;--h4: 1.625rem}}*,*:before,*:after{box-sizing:border-box}html,body,#root{height:100%}body{margin:0;font-family:var(--font-sans);font-size:var(--p2);line-height:1.55;color:var(--lumos-text);background:var(--lumos-surface);-webkit-font-smoothing:antialiased}h1,h2,h3,h4,h5,h6{margin:0;font-weight:600;letter-spacing:-.02em;line-height:1.15;color:var(--lumos-black)}p{margin:0}a{color:var(--lumos-orange);text-decoration:none}a:hover{text-decoration:underline}button{font:inherit}:focus-visible{outline:2px solid var(--lumos-orange);outline-offset:2px;border-radius:4px}.shell{display:flex;flex-direction:column;min-height:100%}.nav{position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:1.5rem;padding:0 1.75rem;height:68px;background:var(--lumos-white);border-bottom:1px solid var(--lumos-border-subtle)}.nav__brand{display:flex;align-items:center;gap:.625rem;font-size:var(--p1);font-weight:600;letter-spacing:-.03em;color:var(--lumos-black);text-decoration:none}.nav__brand:hover{text-decoration:none}.nav__mark{display:grid;place-items:center;width:30px;height:30px;border-radius:9px;background:var(--lumos-orange);color:var(--lumos-white);font-size:.8rem;font-weight:700}.nav__divider{width:1px;height:22px;background:var(--lumos-border)}.nav__label{font-size:var(--p3);color:var(--lumos-text-muted);letter-spacing:-.01em}.nav__links{display:flex;gap:.25rem;margin-left:auto;align-items:center}.nav__link{padding:.45rem .8rem;border-radius:var(--radius-sm);font-size:var(--p3);font-weight:500;color:var(--lumos-text-muted);transition:background var(--transition),color var(--transition)}.nav__link:hover{background:var(--lumos-nav-bg);color:var(--lumos-black);text-decoration:none}.nav__link--active{background:var(--lumos-orange-faint);color:var(--lumos-orange-dark)}.nav__user{display:flex;align-items:center;gap:.6rem;padding-left:.9rem;margin-left:.4rem;border-left:1px solid var(--lumos-border-subtle)}.avatar{display:grid;place-items:center;width:32px;height:32px;border-radius:var(--radius-pill);background:var(--lumos-black);color:var(--lumos-white);font-size:var(--p4);font-weight:600;flex-shrink:0}.main{flex:1;width:100%;max-width:1120px;margin:0 auto;padding:2.5rem 1.75rem 4rem}.main--narrow{max-width:760px}.footer{padding:1.5rem 1.75rem;border-top:1px solid var(--lumos-border-subtle);font-size:var(--p4);color:var(--lumos-icon-gray);text-align:center}.page-header{margin-bottom:2rem}.eyebrow{display:block;margin-bottom:.6rem;font-size:var(--eyebrow);font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--lumos-orange)}.page-title{font-size:var(--h1);margin-bottom:.55rem}.page-subtitle{font-size:var(--p1);color:var(--lumos-text-muted);max-width:62ch}.section-title{font-size:var(--h4);margin-bottom:.35rem}.muted{color:var(--lumos-text-muted)}.small{font-size:var(--p3)}.tiny{font-size:var(--p4)}.mono{font-family:var(--font-mono);font-size:.85em}.card{background:var(--lumos-white);border:1px solid var(--lumos-border-subtle);border-radius:var(--radius);padding:1.5rem;box-shadow:var(--shadow-sm)}.card--flush{padding:0;overflow:hidden}.card--dark{background:var(--lumos-card-dark);border-color:var(--lumos-border-on-dark);color:var(--lumos-text-on-dark)}.card--dark h1,.card--dark h2,.card--dark h3{color:var(--lumos-white)}.stack{display:flex;flex-direction:column;gap:1rem}.stack--lg{gap:1.75rem}.stack--sm{gap:.5rem}.row{display:flex;align-items:center;gap:.75rem}.row--between{justify-content:space-between}.row--wrap{flex-wrap:wrap}.spacer{flex:1}.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5rem;padding:.7rem 1.35rem;border:1px solid transparent;border-radius:var(--radius-sm);font-size:var(--p3);font-weight:600;letter-spacing:-.01em;cursor:pointer;transition:background var(--transition),border-color var(--transition),color var(--transition),transform var(--transition);white-space:nowrap}.btn:active:not(:disabled){transform:translateY(1px)}.btn:disabled{opacity:.45;cursor:not-allowed}.btn--primary{background:var(--lumos-orange-button);color:var(--lumos-white)}.btn--primary:hover:not(:disabled){background:var(--lumos-orange-dark)}.btn--dark{background:var(--lumos-black);color:var(--lumos-white)}.btn--dark:hover:not(:disabled){background:var(--lumos-charcoal)}.btn--secondary{background:var(--lumos-white);border-color:var(--lumos-border);color:var(--lumos-text)}.btn--secondary:hover:not(:disabled){border-color:var(--lumos-black);background:var(--lumos-nav-bg)}.btn--ghost{background:transparent;color:var(--lumos-text-muted)}.btn--ghost:hover:not(:disabled){background:var(--lumos-nav-bg);color:var(--lumos-black)}.btn--danger{background:var(--lumos-white);border-color:var(--lumos-border);color:var(--lumos-red)}.btn--danger:hover:not(:disabled){background:var(--lumos-red-bg);border-color:var(--lumos-red)}.btn--sm{padding:.4rem .8rem;font-size:var(--p4)}.btn--lg{padding:.9rem 1.8rem;font-size:var(--p2)}.btn--block{width:100%}.badge{display:inline-flex;align-items:center;gap:.35rem;padding:.22rem .65rem;border-radius:var(--radius-pill);font-size:var(--p4);font-weight:600;letter-spacing:-.005em;white-space:nowrap}.badge--passed{background:var(--lumos-green-bg);color:var(--lumos-green-text)}.badge--locked{background:var(--lumos-border-subtle);color:var(--lumos-icon-gray)}.badge--ready{background:var(--lumos-orange-faint);color:var(--lumos-orange-dark)}.badge--video{background:#eef4fd;color:var(--lumos-blue)}.badge--warn{background:var(--lumos-yellow-bg);color:#8a6100}.badge--danger{background:var(--lumos-red-bg);color:var(--lumos-red)}.badge--neutral{background:var(--lumos-nav-bg);color:var(--lumos-text-muted)}.progress{height:8px;border-radius:var(--radius-pill);background:var(--lumos-border-subtle);overflow:hidden}.progress__fill{height:100%;border-radius:var(--radius-pill);background:linear-gradient(90deg,var(--lumos-orange) 0%,var(--lumos-orange-medium) 100%);transition:width .32s cubic-bezier(.4,0,.2,1)}.progress__fill--done{background:var(--lumos-green)}.ring{transform:rotate(-90deg)}.ring__track{stroke:var(--lumos-border-subtle)}.ring__value{stroke:var(--lumos-orange);stroke-linecap:round;transition:stroke-dashoffset .42s cubic-bezier(.4,0,.2,1)}.ring__value--done{stroke:var(--lumos-green)}.ring-wrap{position:relative;display:grid;place-items:center;flex-shrink:0}.ring-wrap__label{position:absolute;display:flex;flex-direction:column;align-items:center;line-height:1}.ring-wrap__pct{font-size:var(--h4);font-weight:600;letter-spacing:-.03em}.field{display:flex;flex-direction:column;gap:.4rem}.label{font-size:var(--p4);font-weight:600;color:var(--lumos-text-muted)}.input,.select{width:100%;padding:.65rem .85rem;border:1px solid var(--lumos-border);border-radius:var(--radius-sm);background:var(--lumos-white);font-family:inherit;font-size:var(--p3);color:var(--lumos-text);transition:border-color var(--transition),box-shadow var(--transition)}.input:focus,.select:focus{outline:none;border-color:var(--lumos-orange);box-shadow:0 0 0 3px #ff450b1f}.input--sm{padding:.4rem .55rem;font-size:var(--p4)}.input--num{width:76px;text-align:center}.checkbox{display:inline-flex;align-items:center;gap:.5rem;font-size:var(--p3);cursor:pointer}.checkbox input{width:16px;height:16px;accent-color:var(--lumos-orange);cursor:pointer}.hint{font-size:var(--p4);color:var(--lumos-icon-gray)}.alert{padding:.8rem 1rem;border-radius:var(--radius-sm);border:1px solid;font-size:var(--p3)}.alert--error{background:var(--lumos-red-bg);border-color:#f5c6c9;color:#96261a}.alert--success{background:var(--lumos-green-bg);border-color:#5ee3a380;color:var(--lumos-green-text)}.alert--info{background:var(--lumos-yellow-bg);border-color:var(--lumos-yellow-border);color:#8a6100}.table{width:100%;border-collapse:collapse;font-size:var(--p3)}.table th{text-align:left;padding:.7rem 1rem;font-size:var(--p4);font-weight:600;color:var(--lumos-text-muted);background:var(--lumos-surface-alt);border-bottom:1px solid var(--lumos-border-subtle);white-space:nowrap}.table td{padding:.8rem 1rem;border-bottom:1px solid var(--lumos-border-subtle);vertical-align:middle}.table tbody tr:last-child td{border-bottom:none}.table tbody tr:hover{background:var(--lumos-surface)}.table__scroll{overflow-x:auto}.login{display:grid;grid-template-columns:1fr 1fr;min-height:100vh}.login__aside{display:flex;flex-direction:column;justify-content:space-between;padding:3rem;background:var(--lumos-black-deep);color:var(--lumos-text-on-dark);background-image:radial-gradient(circle at 15% 85%,rgba(255,69,11,.25) 0%,transparent 45%),radial-gradient(circle at 85% 15%,rgba(151,71,255,.18) 0%,transparent 45%)}.login__headline{font-size:var(--h1);color:var(--lumos-white);max-width:14ch;margin-bottom:1rem}.login__panel{display:grid;place-items:center;padding:3rem 2rem;background:var(--lumos-white)}.login__form{width:100%;max-width:380px}.login__list{display:flex;flex-direction:column;gap:.85rem;margin:0;padding:0;list-style:none;font-size:var(--p3)}.login__list li{display:flex;gap:.65rem;align-items:flex-start}.divider{display:flex;align-items:center;gap:.75rem;margin:1.25rem 0;font-size:var(--p4);color:var(--lumos-icon-gray)}.divider:before,.divider:after{content:"";flex:1;height:1px;background:var(--lumos-border-subtle)}@media (max-width: 900px){.login{grid-template-columns:1fr}.login__aside{display:none}}.class-card{border:1px solid var(--lumos-border-subtle);border-radius:var(--radius);background:var(--lumos-white);overflow:hidden;box-shadow:var(--shadow-sm)}.class-card--locked{background:var(--lumos-surface-alt);opacity:.85}.class-card__head{display:flex;align-items:flex-start;gap:1.25rem;padding:1.5rem;border-bottom:1px solid var(--lumos-border-subtle)}.class-card__code{display:grid;place-items:center;width:56px;height:56px;border-radius:var(--radius-sm);background:var(--lumos-black);color:var(--lumos-white);font-size:var(--p1);font-weight:600;letter-spacing:-.03em;flex-shrink:0}.class-card--locked .class-card__code{background:var(--lumos-border);color:var(--lumos-white)}.class-card--passed .class-card__code{background:var(--lumos-green);color:#06371f}.module-row{display:flex;align-items:center;gap:1rem;padding:1rem 1.5rem;border-bottom:1px solid var(--lumos-border-subtle);transition:background var(--transition)}.module-row:last-child{border-bottom:none}.module-row--actionable:hover{background:var(--lumos-beige)}.module-row__num{display:grid;place-items:center;width:30px;height:30px;border-radius:var(--radius-pill);background:var(--lumos-nav-bg);color:var(--lumos-text-muted);font-size:var(--p4);font-weight:600;flex-shrink:0}.module-row__num--passed{background:var(--lumos-green);color:#06371f}.module-row__num--current{background:var(--lumos-orange);color:var(--lumos-white)}.module-row__body{min-width:0;flex:1}.module-row__title{font-weight:600;letter-spacing:-.01em}.player{width:100%;border-radius:var(--radius);background:#000;display:block;aspect-ratio:16 / 9;max-height:min(68vh,620px);object-fit:contain}.player-shell{border-radius:var(--radius);overflow:hidden;background:#000;box-shadow:var(--shadow)}.player-placeholder{display:grid;place-items:center;aspect-ratio:16 / 9;max-height:min(68vh,620px);background:var(--lumos-card-dark);color:var(--lumos-text-on-dark);text-align:center;padding:2rem;border-radius:var(--radius)}.playlist{list-style:none;margin:1rem 0 0;padding:0;display:flex;flex-direction:column;gap:.4rem}.playlist__row{display:flex;align-items:center;gap:.75rem;width:100%;padding:.6rem .75rem;border:1px solid var(--lumos-border-subtle);border-radius:var(--radius-sm);background:var(--lumos-white);text-align:left;cursor:pointer;transition:border-color var(--transition),background var(--transition)}.playlist__row:hover:not(:disabled){border-color:var(--lumos-black);background:var(--lumos-beige)}.playlist__row--active{border-color:var(--lumos-orange);background:var(--lumos-orange-faint)}.playlist__row--missing,.playlist__row:disabled{opacity:.55;cursor:not-allowed}.playlist__mark{display:grid;place-items:center;width:26px;height:26px;border-radius:var(--radius-pill);background:var(--lumos-nav-bg);color:var(--lumos-text-muted);font-size:var(--p4);font-weight:600;flex-shrink:0}.playlist__mark--done{background:var(--lumos-green);color:#06371f}.playlist__mark--active{background:var(--lumos-orange);color:var(--lumos-white)}.playlist__body{display:flex;flex-direction:column;min-width:0;flex:1}.playlist__title{font-size:var(--p3);font-weight:600;letter-spacing:-.01em}.playlist__bar{width:56px;height:4px;border-radius:var(--radius-pill);background:var(--lumos-border-subtle);overflow:hidden;flex-shrink:0}.playlist__bar>span{display:block;height:100%;background:var(--lumos-orange);border-radius:var(--radius-pill)}.quiz{max-width:720px;margin:0 auto}.quiz__meter{display:flex;gap:1.5rem;padding:1rem 1.35rem;border-radius:var(--radius);background:var(--lumos-white);border:1px solid var(--lumos-border-subtle);margin-bottom:1.5rem}.meter{flex:1}.meter__label{font-size:var(--p4);color:var(--lumos-text-muted);margin-bottom:.3rem}.meter__value{font-size:var(--h5);font-weight:600;letter-spacing:-.02em}.meter__value--danger{color:var(--lumos-red)}.meter__value--good{color:var(--lumos-green-text)}.pips{display:flex;gap:4px;margin-top:.4rem}.pip{width:100%;height:5px;border-radius:var(--radius-pill);background:var(--lumos-border-subtle)}.pip--correct{background:var(--lumos-green)}.pip--wrong{background:var(--lumos-tomato)}.question{font-size:var(--h4);line-height:1.35;margin-bottom:1.5rem}.options{display:flex;flex-direction:column;gap:.65rem}.option{display:flex;align-items:flex-start;gap:.85rem;width:100%;padding:1rem 1.15rem;text-align:left;background:var(--lumos-white);border:1.5px solid var(--lumos-border);border-radius:var(--radius-sm);cursor:pointer;transition:border-color var(--transition),background var(--transition)}.option:hover:not(:disabled){border-color:var(--lumos-black);background:var(--lumos-beige)}.option:disabled{cursor:default}.option--selected{border-color:var(--lumos-orange);background:var(--lumos-orange-faint)}.option--correct{border-color:var(--lumos-green);background:var(--lumos-green-bg)}.option--wrong{border-color:var(--lumos-tomato);background:var(--lumos-red-bg)}.option__key{display:grid;place-items:center;width:26px;height:26px;border-radius:var(--radius-sm);background:var(--lumos-nav-bg);color:var(--lumos-text-muted);font-size:var(--p4);font-weight:600;flex-shrink:0}.option--selected .option__key{background:var(--lumos-orange);color:var(--lumos-white)}.option--correct .option__key{background:var(--lumos-green);color:#06371f}.option--wrong .option__key{background:var(--lumos-tomato);color:var(--lumos-white)}.verdict{margin-top:1.25rem;padding:1rem 1.15rem;border-radius:var(--radius-sm);border-left:4px solid}.verdict--correct{background:var(--lumos-green-bg);border-color:var(--lumos-green)}.verdict--wrong{background:var(--lumos-red-bg);border-color:var(--lumos-tomato)}.verdict__title{font-weight:600;margin-bottom:.25rem}.result{text-align:center;padding:3rem 2rem}.result__icon{display:grid;place-items:center;width:72px;height:72px;margin:0 auto 1.25rem;border-radius:var(--radius-pill);font-size:2rem}.result__icon--pass{background:var(--lumos-green-bg)}.result__icon--fail{background:var(--lumos-red-bg)}.grid-2{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:1rem}.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:1rem}@media (max-width: 860px){.grid-4{grid-template-columns:repeat(2,1fr)}}.stat{padding:1.15rem 1.25rem;border-radius:var(--radius);background:var(--lumos-white);border:1px solid var(--lumos-border-subtle)}.stat__value{font-size:var(--h2);font-weight:600;letter-spacing:-.03em;line-height:1;margin-bottom:.3rem}.stat__label{font-size:var(--p4);color:var(--lumos-text-muted)}.spinner{width:22px;height:22px;border:2.5px solid var(--lumos-border-subtle);border-top-color:var(--lumos-orange);border-radius:var(--radius-pill);animation:spin .7s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.center-screen{display:grid;place-items:center;min-height:60vh}.empty{padding:3rem 2rem;text-align:center;color:var(--lumos-text-muted)}.modal-backdrop{position:fixed;top:0;right:0;bottom:0;left:0;z-index:60;display:grid;place-items:center;padding:1.5rem;background:#1210138c}.modal{width:100%;max-width:480px;background:var(--lumos-white);border-radius:var(--radius);padding:1.75rem;box-shadow:var(--shadow-lg);max-height:90vh;overflow-y:auto}@media (max-width: 720px){.main{padding:1.75rem 1rem 3rem}.nav{padding:0 1rem;gap:.75rem}.nav__label,.nav__divider{display:none}.quiz__meter{flex-direction:column;gap:.85rem}}