:root{--bg:#f5f7fb;--panel:#fff;--ink:#172033;--muted:#667085;--line:#e4e8f0;--nav:#111827;--nav2:#1f2937;--primary:#3157e3;--primary2:#2341b5;--success:#16845b;--danger:#b42318;--shadow:0 10px 30px rgba(17,24,39,.07)}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--bg);line-height:1.6}a{color:inherit;text-decoration:none}button,input,select,textarea{font:inherit}.app-shell{min-height:100vh}.sidebar{position:fixed;inset:0 auto 0 0;width:250px;background:linear-gradient(180deg,var(--nav),#0b1220);color:#fff;padding:26px 18px;display:flex;flex-direction:column;z-index:20}.brand{display:flex;gap:12px;align-items:center}.brand-mark{display:grid;place-items:center;width:40px;height:40px;border-radius:12px;background:#fff;color:#111827;font-weight:900}.brand strong,.brand small{display:block}.brand small{font-size:12px;color:#9ca3af;font-weight:500}.sidebar nav{display:grid;gap:7px;margin-top:42px}.nav-link{padding:11px 13px;border-radius:10px;color:#cbd5e1;font-size:14px}.nav-link:hover,.nav-link.active{background:rgba(255,255,255,.09);color:#fff}.sidebar-note{margin-top:auto;padding:15px;border:1px solid rgba(255,255,255,.12);border-radius:12px;color:#cbd5e1;font-size:12px}.sidebar-note strong,.sidebar-note span{display:block}.main{margin-left:250px;min-width:0}.topbar{height:72px;background:rgba(255,255,255,.92);border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 34px;position:sticky;top:0;z-index:10;backdrop-filter:blur(12px)}.search-box input{width:min(360px,35vw);border:1px solid var(--line);border-radius:10px;padding:10px 13px;background:#f8fafc;outline:none}.search-box input:focus{border-color:#8da2f4;background:#fff;box-shadow:0 0 0 3px rgba(49,87,227,.08)}.user-actions{display:flex;gap:16px;align-items:center;font-size:14px}.link-button{border:0;background:none;color:var(--primary);cursor:pointer;padding:0}.page{max-width:1240px;margin:0 auto;padding:42px 36px 70px}.hero{padding:36px;border-radius:24px;background:linear-gradient(135deg,#121a2c,#243b78);color:#fff;display:flex;justify-content:space-between;gap:30px;align-items:end;box-shadow:var(--shadow)}.hero.compact{padding:28px}.hero h1{font-size:clamp(32px,4vw,54px);line-height:1.05;max-width:720px;margin:8px 0 14px;letter-spacing:-.03em}.hero.compact h1{font-size:38px}.hero p{max-width:680px;color:#dbe4ff;margin:0}.eyebrow{text-transform:uppercase;letter-spacing:.16em;font-size:11px;font-weight:800;color:#7181a7}.hero .eyebrow{color:#9fb3ff}.button{display:inline-flex;align-items:center;justify-content:center;border-radius:10px;padding:11px 15px;border:1px solid transparent;font-weight:700;cursor:pointer;white-space:nowrap}.button.primary{background:var(--primary);color:#fff}.hero .button.primary{background:#fff;color:#1e326e}.button.primary:hover{background:var(--primary2)}.hero .button.primary:hover{background:#eef2ff}.button.secondary{background:#fff;border-color:var(--line);color:var(--ink)}.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:14px;margin:20px 0 42px}.stat{background:var(--panel);border:1px solid var(--line);border-radius:15px;padding:20px;box-shadow:0 4px 12px rgba(17,24,39,.025)}.stat strong{display:block;font-size:27px;letter-spacing:-.03em}.stat span{color:var(--muted);font-size:13px}.section-head,.page-head,.topic-header{display:flex;justify-content:space-between;gap:24px;align-items:flex-end;margin:0 0 22px}.page-head,.topic-header{align-items:flex-start}.section-head h2,.page-head h1,.topic-header h1{margin:4px 0 6px;letter-spacing:-.025em}.page-head h1,.topic-header h1{font-size:clamp(30px,4vw,46px);line-height:1.1}.page-head p,.topic-header p{max-width:780px;margin:0;color:var(--muted)}.section-head a,.back{color:var(--primary);font-size:14px}.module-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}.module-card{background:#fff;border:1px solid var(--line);border-radius:18px;padding:25px;box-shadow:0 4px 14px rgba(17,24,39,.03);position:relative;overflow:hidden;transition:.18s transform,.18s box-shadow}.module-card:hover{transform:translateY(-2px);box-shadow:var(--shadow)}.module-card:before{content:"";position:absolute;inset:0 auto 0 0;width:4px;background:#7284b8}.module-card.accent-blue:before{background:#3157e3}.module-card.accent-emerald:before{background:#16a36f}.module-card.accent-violet:before{background:#7c4dff}.module-card.accent-amber:before{background:#e49a1f}.module-card h3{font-size:21px;margin:8px 0}.module-card p{color:var(--muted);font-size:14px;min-height:67px}.module-number,.lab-number,.quiz-num{font-size:11px;letter-spacing:.12em;text-transform:uppercase;color:#7783a0;font-weight:800}.progress{height:7px;border-radius:99px;background:#edf0f5;overflow:hidden;margin:18px 0 8px}.progress span{display:block;height:100%;background:var(--primary);border-radius:99px}.module-card small{color:var(--muted)}.topic-list{display:grid;gap:10px}.topic-row{display:grid;grid-template-columns:52px 1fr auto;gap:15px;align-items:center;background:#fff;border:1px solid var(--line);border-radius:14px;padding:18px 20px}.topic-row:hover{border-color:#b9c4e8}.topic-num{width:42px;height:42px;border-radius:12px;background:#f0f3fa;display:grid;place-items:center;font-weight:800;color:#4b5d8b}.topic-row h3{margin:0 0 3px;font-size:16px}.topic-row p{margin:0;color:var(--muted);font-size:13px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}.status-pill{font-size:11px;padding:6px 9px;border-radius:99px;background:#f1f3f7;color:#586174}.status-pill.done{background:#e9f8f2;color:var(--success)}.study-section{background:#fff;border:1px solid var(--line);border-radius:18px;padding:28px;margin:18px 0}.study-section h2{margin-top:0;font-size:23px}.study-section h3{margin-top:28px}.concept-table{border:1px solid var(--line);border-radius:12px;overflow:hidden}.concept-head,.concept-row{display:grid;grid-template-columns:minmax(130px,.8fr) 1.4fr 1.4fr;gap:20px;padding:14px 16px}.concept-head{background:#f4f6fa;font-size:12px;font-weight:800;color:#5d6780}.concept-row{border-top:1px solid var(--line);font-size:14px}.scenario,.safety{border-left:4px solid #516dd8;background:#edf2ff;border-radius:12px;padding:19px 22px;margin:18px 0}.scenario p,.safety p{margin:4px 0 0}.safety{border-left-color:#e59d20;background:#fff7e8}.answer-stack{display:grid;gap:10px}.qa{background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden}.qa summary{list-style:none;cursor:pointer;padding:16px 18px;font-weight:700}.qa summary::-webkit-details-marker{display:none}.qa summary:after{content:"+";float:right;color:#8892aa;font-size:20px}.qa[open] summary:after{content:"−"}.qa>div,.qa>p{border-top:1px solid var(--line);padding:16px 18px;margin:0;background:#fafbfc}.qa p{margin:6px 0 0}.answer-label{font-size:10px;font-weight:900;text-transform:uppercase;letter-spacing:.14em;color:var(--primary)}.pager{display:flex;justify-content:space-between;margin-top:24px}.pager a{color:var(--primary);font-weight:700}.lab-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.lab-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:22px}.lab-card h3{margin:7px 0}.lab-card p{color:var(--muted);font-size:13px;min-height:88px}.lab-card small{color:var(--primary);font-weight:700}.stack{display:grid;gap:15px}.stack label:not(.check){display:grid;gap:7px;font-weight:700;font-size:13px}.stack input[type=email],.stack input[type=password],textarea,select{border:1px solid var(--line);border-radius:10px;padding:11px 12px;background:#fff;color:var(--ink);outline:none}textarea{width:100%;resize:vertical}.check{display:flex;align-items:flex-start;gap:9px;font-size:13px;color:#4f5b73}.quiz-card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:23px}.quiz-card h3{margin:6px 0 14px}.quiz-card textarea{margin-bottom:12px}.confidence{margin-top:12px}.submit-quiz{justify-self:start}.size-picker label{font-size:13px;font-weight:700}.size-picker select{margin-left:8px}.your-answer,.model-answer{padding:14px;border-radius:10px;background:#f5f7fb;margin-top:12px}.model-answer{background:#eef8f4}.your-answer p,.model-answer p{margin:5px 0}.q-index{display:inline-grid;place-items:center;width:27px;height:27px;margin-right:9px;border-radius:7px;background:#eef1f7;color:#506086;font-size:12px}.flash{background:#e9f8f2;color:#166747;border:1px solid #c3eadb;border-radius:10px;padding:12px 15px;margin-bottom:18px}.muted{color:var(--muted)}.large-copy{font-size:17px}.empty{padding:40px;background:#fff;border:1px dashed #cbd2df;border-radius:16px;text-align:center;color:var(--muted)}.login-page{min-height:100vh;display:grid;place-items:center;padding:24px;background:radial-gradient(circle at 20% 10%,#e8edff,transparent 35%),#f5f7fb}.login-card{width:min(440px,100%);background:#fff;border:1px solid var(--line);border-radius:22px;padding:34px;box-shadow:var(--shadow)}.login-brand{color:var(--ink);margin-bottom:34px}.login-brand .brand-mark{background:#172033;color:#fff}.login-card h1{margin:0;font-size:34px}.login-card .button{width:100%;margin-top:4px}.security-note{font-size:12px;color:var(--muted);text-align:center;margin:20px 0 0}.error{background:#fff0ef;color:var(--danger);padding:10px;border-radius:8px;font-size:13px}@media(max-width:980px){.sidebar{width:205px}.main{margin-left:205px}.page{padding:28px 22px}.topbar{padding:0 22px}.stats{grid-template-columns:repeat(2,1fr)}.lab-grid{grid-template-columns:repeat(2,1fr)}}@media(max-width:740px){.sidebar{position:static;width:auto;height:auto;padding:15px 18px;display:block}.sidebar nav{display:flex;overflow:auto;margin-top:14px;gap:5px}.sidebar-note{display:none}.nav-link{white-space:nowrap}.main{margin-left:0}.topbar{position:static;height:auto;padding:14px 18px;gap:12px}.search-box{flex:1}.search-box input{width:100%}.user-actions span{display:none}.page{padding:24px 15px 50px}.hero,.section-head,.page-head,.topic-header{display:block}.hero .button,.page-head .button,.topic-header form{margin-top:20px}.stats{grid-template-columns:1fr 1fr}.module-grid,.lab-grid{grid-template-columns:1fr}.concept-table{overflow:auto}.concept-head,.concept-row{min-width:720px}.topic-row{grid-template-columns:44px 1fr}.topic-row .status-pill{grid-column:2;justify-self:start}.hero h1{font-size:36px}}