:root{--navy:#172f3c;--ink:#203945;--muted:#60717b;--green:#236252;--mint:#bdebd8;--line:#dde5e8;--paper:#f4f7f8;--accent:#d94e28}*{box-sizing:border-box}body{margin:0;font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--paper);font-size:16px;line-height:1.55}button,a,input{ -webkit-tap-highlight-color:transparent}button{font:inherit;cursor:pointer}a{color:var(--green);text-underline-offset:4px}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #df6a36;outline-offset:4px}button:disabled{cursor:not-allowed;opacity:.5}.skip{position:fixed;top:-80px;z-index:9;background:white;padding:15px}.skip:focus{top:5px}#sidebar{position:fixed;inset:0 auto 0 0;width:285px;background:var(--navy);color:white;display:flex;flex-direction:column;padding:30px 22px 20px;z-index:5}.brand{display:flex;align-items:center;gap:11px;color:white;text-decoration:none;font-size:37px;line-height:1;letter-spacing:-1px;margin:0 5px 40px}.brand-mark{font-size:26px;border:1px solid #769b9a;border-radius:11px;padding:10px;color:var(--mint)}.university{display:block;font-size:12px;letter-spacing:4px;margin-top:10px}.course-label,.eyebrow{font-size:12px;font-weight:700;letter-spacing:1.8px;color:#a8c4c9}#sidebar h2{font-size:19px;margin:8px 0 0}.sidebar-sub{font-size:14px;color:#b5c9d0;margin:5px 0 20px}progress{width:100%;height:5px;border:0;border-radius:8px;overflow:hidden;accent-color:var(--mint);background:#3b515d}progress::-webkit-progress-bar{background:#3b515d}progress::-webkit-progress-value{background:var(--mint)}.progress-label{display:flex;justify-content:space-between;font-size:13px;color:#bdd3d8;margin:6px 0 17px}#lessons{overflow:auto;margin:0 -10px;padding:0 10px;scrollbar-width:thin;scrollbar-color:#57727d transparent;flex:1}.group-label{font-size:11px;text-transform:uppercase;letter-spacing:1.7px;color:#a1b9c2;margin:24px 0 12px}.lesson-link{display:flex;align-items:center;gap:11px;text-decoration:none;color:#dce8ec;padding:11px 9px;border-radius:6px;line-height:1.3;margin:2px 0;font-size:14px}.lesson-link:hover{background:#264653}.lesson-link.active{background:#d7eee6;color:#173d35}.number{border:1px solid #657c86;border-radius:50%;height:25px;min-width:25px;display:grid;place-items:center;font-size:12px}.active .number{background:var(--green);color:white;border-color:var(--green)}.done .number{background:#375d52;color:var(--mint);border-color:#507d6d}.sidebar-foot{border-top:1px solid #3a515d;padding-top:15px;font-size:12px;color:#b9ced4;margin-top:15px}.text-button{background:none;border:0;color:inherit;font-size:13px;text-decoration:underline;padding:5px 0}.workspace{margin-left:285px}.topbar{height:78px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 40px;background:white;font-size:14px;gap:15px}.topbar>a{text-decoration:none}.slash{margin:0 12px;color:#a0aeb4}.topbar strong{font-weight:500}main{max-width:1500px;margin:auto;padding:36px 40px 22px}.eyebrow{color:var(--green);margin:0 0 12px}h1{font-size:clamp(29px,2.6vw,42px);font-weight:550;line-height:1.15;letter-spacing:-1.4px;margin:0 0 14px}h2,h3{line-height:1.25}h2{font-size:24px}h3{font-size:19px}.intro{color:var(--muted);margin:0;max-width:820px}.lesson-head{display:flex;justify-content:space-between;align-items:flex-start;gap:24px;margin-bottom:28px}.duration{white-space:nowrap;font-size:13px;color:var(--green);background:#e5efe9;border-radius:30px;padding:8px 13px;margin-top:6px}.tabs{display:flex;gap:30px;border-bottom:1px solid var(--line);margin-bottom:25px}.tab{background:none;border:0;border-bottom:3px solid transparent;padding:12px 0;color:var(--muted);font-size:15px}.tab.active{border-color:var(--green);color:var(--green);font-weight:650}.walk-layout{display:grid;grid-template-columns:minmax(0,1fr) 290px;gap:24px;align-items:start}.screen-card{border:1px solid var(--line);border-radius:12px;background:white;overflow:hidden}.screen-bar{display:flex;justify-content:space-between;align-items:center;padding:12px 18px;border-bottom:1px solid var(--line);font-size:12px;color:var(--muted);gap:12px}.screen-bar strong{font-size:13px;color:var(--ink)}.screen-stage{padding:18px;background:#eaf0f2;display:flex;align-items:center;justify-content:center;min-height:280px}.screenshot{position:relative;width:100%;max-width:900px;line-height:0}.screenshot img{display:block;width:100%;height:auto;max-height:470px;object-fit:contain}.screenshot.portrait{width:auto;max-width:100%}.screenshot.portrait img{width:auto;max-width:100%;max-height:480px}.hotspot{position:absolute;border:3px solid #ed602f;background:rgba(239,105,49,.13);border-radius:7px;box-shadow:0 0 0 4px #fff9;min-width:26px;min-height:26px}.hotspot:hover{background:#f07b3340}.hotspot span{position:absolute;top:-14px;left:-13px;border-radius:50%;background:#c34620;color:white;width:26px;height:26px;display:grid;place-items:center;font-weight:700;font-size:13px;line-height:1}.caption{padding:10px 18px;margin:0;color:var(--muted);font-size:12px;border-top:1px solid var(--line)}.caption a{color:inherit}.coach{background:white;border:1px solid var(--line);border-radius:12px;padding:23px}.step-count{color:var(--green);font-size:12px;letter-spacing:1.2px;font-weight:700}.coach h2{font-size:23px;margin:13px 0}.coach p{font-size:15px;color:var(--muted)}.hint{background:#f0f5f2;border-left:3px solid #79a993;padding:12px 14px;font-size:14px;margin-top:20px}.hint strong{display:block;color:var(--green);margin-bottom:3px}.primary,.secondary{border-radius:7px;padding:11px 19px;font-weight:600;font-size:14px}.primary{border:1px solid var(--green);background:var(--green);color:white}.primary:hover{background:#164b3d}.secondary{border:1px solid #c7d4d8;color:var(--ink);background:white}.secondary:hover{background:#f0f5f6}.coach .primary{width:100%;margin-top:18px}.step-nav{display:flex;align-items:center;justify-content:space-between;margin-top:18px;gap:16px}.dots{display:flex;gap:7px}.dot{width:10px;height:10px;border-radius:50%;background:#d5e1e5;border:0;padding:0}.dot.active{background:var(--green)}.dot.checked{background:#75a892}.below{display:grid;grid-template-columns:1fr 1fr;gap:24px;margin-top:26px}.note{padding:20px 22px;border-top:1px solid #cddade}.note h3{font-size:15px;margin:0 0 9px}.note p{font-size:14px;color:var(--muted);margin:0}.lesson-footer{border-top:1px solid var(--line);margin-top:26px;padding-top:20px;display:flex;align-items:center;justify-content:space-between;gap:20px}.lesson-footer p{font-size:13px;color:var(--muted);margin:0}.page-foot{max-width:1500px;padding:18px 40px 25px;margin:auto;font-size:12px;color:var(--muted);display:flex;justify-content:space-between;gap:20px}.mobile-menu{display:none}.video-wrap{aspect-ratio:16/9;background:var(--navy);border-radius:10px;overflow:hidden;display:grid;place-items:center;max-width:950px;color:white;text-align:center;padding:25px}.video-wrap iframe{width:100%;height:100%;border:0}.video-wrap.playing{padding:0}.video-wrap h2{color:white}.video-meta{display:flex;gap:20px;align-items:center;margin-top:20px;font-size:14px}.howto{background:white;border:1px solid var(--line);padding:26px;border-radius:12px;max-width:950px}.howto li{padding:9px 0 9px 8px;color:var(--muted)}.howto strong{color:var(--ink)}.howto h2{margin-top:0}.question{border:0;padding:0;margin:25px 0}.question legend{font-size:23px;font-weight:600;margin-bottom:20px}.option{display:flex;gap:13px;border:1px solid var(--line);border-radius:7px;padding:16px;margin:11px 0;cursor:pointer}.option:has(input:checked){background:#ecf6f1;border-color:var(--green)}.option input{accent-color:var(--green);width:18px}.feedback{padding:15px;border-radius:7px;background:#e5f2eb;margin-top:18px}.feedback.error{background:#fff0e6}.complete{padding:35px;background:#e2f1e9;border:1px solid #b5d4c4;border-radius:12px;max-width:900px}.complete h2{font-size:31px}.complete .primary{margin-top:16px}.actions{display:flex;gap:12px;flex-wrap:wrap}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}dialog{border:1px solid var(--line);border-radius:12px;padding:25px;max-width:min(95vw,1500px);max-height:95vh;color:var(--ink)}dialog::backdrop{background:#0e263bba}#zoom img{display:block;max-width:100%;max-height:80vh;object-fit:contain;margin-top:15px}#reset-dialog{max-width:460px}.badge{display:inline-block;background:#e1f1e9;color:var(--green);font-size:12px;border-radius:20px;padding:3px 10px}.storage-warning{color:#8c3418;background:#ffebdf;padding:12px;border-radius:8px}.source-line{font-size:13px;color:var(--muted);margin-top:20px}.source-line a{color:inherit}@media(min-width:1500px){.walk-layout{grid-template-columns:minmax(0,1fr) 330px}.screen-stage{min-height:400px}}@media(max-width:1150px){#sidebar{width:245px;padding:25px 17px}.workspace{margin-left:245px}.topbar{padding:0 25px}main{padding:28px 25px}.walk-layout{grid-template-columns:minmax(0,1fr)}.coach{display:block}.coach .primary{width:auto}.coach p{max-width:850px}.screen-stage{min-height:200px}.page-foot{padding:20px 25px}}@media(max-width:760px){#sidebar{display:none;top:65px;width:290px}body.menu-open #sidebar{display:flex;box-shadow:10px 0 30px #172f3c40}.workspace{margin-left:0}.mobile-menu{display:block}.topbar{height:65px;padding:0 16px}.topbar>span{display:none}.topbar a{font-size:13px}main{padding:27px 18px}.lesson-head{gap:10px}.duration{display:none}h1{font-size:30px}.tabs{gap:20px;overflow:auto;white-space:nowrap}.tab{font-size:14px}.below{grid-template-columns:1fr;gap:0}.screen-stage{padding:10px;min-height:100px}.screen-bar{padding:10px}.screen-bar>span{display:none}.lesson-footer{align-items:flex-start}.lesson-footer .primary{max-width:180px}.page-foot{display:block;padding:20px 18px}.page-foot span{display:block;margin-top:5px}.coach{padding:20px}.video-meta{align-items:flex-start;flex-direction:column}.screenshot.portrait img{max-height:420px}}@media(prefers-reduced-motion:no-preference){button,a{transition:background .15s,color .15s}}
.screenshot img{max-height:none}.hotspot{min-width:0;min-height:0}main:focus{outline:none}
@media(max-width:480px){.tabs{display:grid;grid-template-columns:1fr 1fr;gap:0 20px;overflow:visible}.tab{text-align:left;padding:10px 0}}
.brand{display:flex;flex-direction:column;align-items:center;width:min(225px,100%);gap:0;color:white;text-decoration:none;font-size:inherit;line-height:normal;letter-spacing:normal;margin:0 auto 40px}.brand-logo{display:block;width:100%;height:auto}.university{display:block;font-size:12px;letter-spacing:4px;margin-top:14px;padding-left:4px;text-align:center}