:root{--bg:#f6f7f9;--card-bg:#fff;--border:#e2e5ea;--text:#1a1d23;--muted:#6b7280;--accent:#2563eb;--accent-hover:#1d4ed8;--ok:#16a34a;--ko:#dc2626}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif}.page{max-width:720px;margin:0 auto;padding:48px 20px}.muted{color:var(--muted)}.dropzone{margin-top:24px;border:2px dashed var(--border);border-radius:12px;padding:48px 24px;text-align:center;background:var(--card-bg)}.dropzone-active{border-color:var(--accent);background:#eef4ff}.primary-btn,.secondary-btn{border:none;border-radius:8px;font-size:14px;cursor:pointer}.primary-btn{background:var(--accent);color:#fff}.primary-btn:hover{background:var(--accent-hover)}.primary-btn:disabled{background:#a9c2f0;cursor:not-allowed}.secondary-btn{border:1px solid var(--border);color:var(--text)}.secondary-btn:disabled{color:var(--muted);cursor:not-allowed}.file-btn{display:inline-block;margin-top:12px}.link-btn{margin-top:16px;background:none;border:none;color:var(--accent);cursor:pointer;padding:0}.error-box{margin-top:20px;padding:14px 16px;background:#fef2f2;border:1px solid #fecaca;color:#991b1b;border-radius:8px}.error-box ul{margin:8px 0 0;padding-left:18px}.capability-warning{background:#fffbeb;border:1px solid #fde68a;color:#92400e;padding:10px 14px;margin-bottom:16px}.player-card{background:var(--card-bg);border:1px solid var(--border);border-radius:14px;padding:28px}.player-header h2{margin:0 0 4px}.progress-line{margin-top:20px;font-size:13px;color:var(--muted)}.progress-bar{position:relative;margin-top:6px;height:10px;background:#eceef1;border-radius:999px;overflow:hidden}.progress-fill{height:100%;background:var(--accent);transition:width .2s ease}.progress-pct{display:block;margin-top:6px;font-size:12px;color:var(--muted)}.unit{margin-top:24px}.unit-title{margin-bottom:12px}.block{border:1px solid var(--border);border-radius:10px;padding:16px;margin-bottom:14px}.block h3{margin-top:0}.block p{line-height:1.5}.badge{display:inline-block;font-size:11px;text-transform:uppercase;letter-spacing:.04em;color:var(--accent);background:#eef4ff;border-radius:999px;padding:2px 10px;margin-bottom:8px}.block-unknown{background:#fafafa;color:var(--muted);font-style:italic}.quiz-question{margin-bottom:14px}.quiz-options{display:flex;flex-direction:column;gap:6px;margin-top:6px}.quiz-option{display:flex;align-items:center;gap:8px;font-size:14px}.explain{font-size:13px;margin-top:6px}.explain.ok{color:var(--ok)}.explain.ko{color:var(--ko)}.quiz-result{margin-top:10px;font-size:14px}.player-footer{display:flex;justify-content:space-between;margin-top:20px}.page:has(.course-shell){max-width:1280px;margin:0 auto;padding:24px}.course-shell{display:grid;grid-template-columns:280px minmax(0,1fr);min-height:calc(100vh - 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56px)}.course-sidebar{background:linear-gradient(180deg,#f8fafc,#f4f7fb);border-right:1px solid var(--lp-border);padding:28px 22px;gap:26px}.sidebar-eyebrow{color:var(--lp-primary);font-size:10px;font-weight:800;letter-spacing:.14em}.sidebar-brand h2{margin-top:8px;font-size:20px;line-height:1.3;color:var(--lp-text)}.sidebar-meta span{background:#fff;border:1px solid var(--lp-border);color:var(--lp-muted);padding:4px 10px;box-shadow:0 2px 5px rgba(23,32,51,.03)}.nav-module-title{font-size:10px;font-weight:800;letter-spacing:.09em;color:#8a95a7;margin-bottom:9px}.nav-unit{min-height:42px;padding:9px 10px;border-radius:10px;color:#344054;transition:background .15s ease,color .15s ease,transform .15s ease}.nav-unit:hover{background:#fff;box-shadow:0 3px 10px rgba(23,32,51,.05)}.nav-unit-active{color:var(--lp-primary);box-shadow:inset 3px 0 0 var(--lp-primary)}.nav-unit-active,.nav-unit-active:hover{background:var(--lp-primary-soft)}.nav-unit-number{width:25px;height:25px;background:#e7ebf0;color:#536174;font-weight:700}.nav-unit-active .nav-unit-number{background:var(--lp-primary);color:#fff}.nav-unit-visited .nav-unit-number{background:var(--lp-success);color:#fff}.sidebar-progress{border-top:1px solid var(--lp-border);padding-top:18px}.sidebar-progress-row{color:var(--lp-muted)}.sidebar-progress-row strong{color:var(--lp-text);font-weight:700}.sidebar-progress .progress-bar{height:8px;background:#e6ebf1}.sidebar-progress .progress-fill{background:linear-gradient(90deg,var(--lp-primary) 0,#4d7ff0 100%)}.course-content{max-width:960px;padding:52px 62px 46px}.content-header{padding-bottom:26px;border-bottom:1px solid var(--lp-border)}.content-breadcrumb{color:var(--lp-primary);font-size:11px;font-weight:800;letter-spacing:.08em}.content-counter{color:#8a95a7;margin-top:7px}.content-header h1{margin-top:12px;font-size:34px;line-height:1.18;color:#101828;letter-spacing:-.02em}.course-description{max-width:760px;font-size:15px;line-height:1.7;color:var(--lp-muted)}.unit-content{margin-top:30px}.unit-content .block{position:relative;margin-bottom:22px;padding:22px 24px;border-radius:14px;box-shadow:var(--lp-shadow-soft)}.unit-content .block h3{margin-bottom:10px;color:#172033;font-size:17px}.unit-content .block p{font-size:15px;line-height:1.7;color:#344054}.block-lesson{background:#fff;border:1px solid var(--lp-border)}.block-example{background:linear-gradient(135deg,#e7f0ff,#f1f6ff);border:1px solid #b9d0ff;border-left:5px solid var(--lp-example-border)}.block-example .badge{background:var(--lp-example-border);color:#fff;font-weight:800;letter-spacing:.06em}.block-example h3{color:#1749a3}.block-exercise{background:linear-gradient(135deg,#fff4d8,#fffaf0);border:1px solid #f0d494;border-left:5px solid var(--lp-exercise-border)}.block-exercise .badge{background:var(--lp-exercise-border);color:#fff;font-weight:800}.block-exercise h3{color:#8a5b00}.block-quiz{background:linear-gradient(135deg,#f3f5f8,#fafbfc);border:1px solid #d5dbe4;border-left:5px solid var(--lp-quiz-border)}.block-quiz .badge{background:#596579;color:#fff;font-weight:800}.quiz-question{padding:14px 0;border-bottom:1px solid #e3e7ed}.quiz-question:last-of-type{border-bottom:0}.quiz-option{padding:10px 12px;border:1px solid var(--lp-border);border-radius:9px;background:#fff;cursor:pointer;transition:border-color .15s ease,background .15s ease}.quiz-option:hover{border-color:#a9b7ca;background:#fbfcfe}.primary-btn,.secondary-btn{min-height:40px;padding:10px 18px;border-radius:9px;font-weight:600}.primary-btn{background:linear-gradient(180deg,#2b63df 0,var(--lp-primary) 100%);box-shadow:0 5px 12px rgba(34,87,214,.18)}.primary-btn:hover{background:linear-gradient(180deg,#2457c9 0,var(--lp-primary-dark) 100%)}.secondary-btn{border:1px solid var(--lp-border-strong);background:#fff;color:#344054}.course-footer{margin-top:38px;padding-top:24px;border-top:1px solid var(--lp-border)}.footer-position{color:#8a95a7;font-weight:600}@media (max-width:1050px){.course-shell{grid-template-columns:270px minmax(0,1fr)}.course-content{padding:42px 38px}}@media (max-width:860px){.page:has(.course-shell){padding:0}.course-shell{display:block;border-radius:0;box-shadow:none}.course-sidebar{position:static;max-height:none;border-right:0;border-bottom:1px solid var(--lp-border)}.course-content{max-width:none;padding:30px 22px}.content-header h1{font-size:28px}}@media (max-width:520px){.course-content{padding:24px 16px}.content-header h1{font-size:25px}.unit-content .block{padding:18px}}