*{box-sizing:border-box}
:root{
  --navy:#1f3b64;
  --blue:#2f6fb2;
  --sky:#eaf4fb;
  --green:#7fbf3f;
  --yellow:#f1c84b;
  --cream:#fffdf7;
  --ink:#243143;
  --muted:#6c7684;
  --line:#d9e1e8;
  --card:#ffffff;
  --bg:#f6f8fb;
}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:Arial,Helvetica,sans-serif;
  background:var(--bg);
  color:var(--ink);
  line-height:1.6;
}
a,button{font:inherit}
a:focus-visible,button:focus-visible{outline:4px solid var(--yellow);outline-offset:3px}
.page{width:min(1040px,calc(100% - 32px));margin:auto}
.skip-link{position:absolute;left:-9999px}
.skip-link:focus{left:12px;top:12px;background:#fff;padding:10px;z-index:1000}

.site-header{
  background:#fff;
  border-bottom:1px solid var(--line);
  position:sticky;
  top:0;
  z-index:50;
}
.header-inner{
  min-height:72px;
  display:flex;
  justify-content:space-between;
  align-items:center;
  gap:18px;
}
.brand{
  text-decoration:none;
  color:var(--navy);
  display:flex;
  gap:10px;
  align-items:center;
}
.brand-mark{
  width:40px;height:40px;
  border-radius:10px;
  background:var(--navy);
  color:#fff;
  display:grid;
  place-items:center;
  font-weight:900;
}
.brand strong,.brand small{display:block}
.brand small{color:var(--muted);font-size:.78rem}
.top-nav{display:flex;gap:8px;flex-wrap:wrap}
.top-nav a{
  text-decoration:none;
  color:var(--navy);
  font-weight:800;
  padding:8px 11px;
  border-radius:8px;
}
.top-nav a:hover,.top-nav a.active{background:var(--sky)}

.hero{
  background:linear-gradient(180deg,#edf6fc,#f6f8fb);
  padding:54px 0 42px;
  border-bottom:1px solid var(--line);
}
.eyebrow{
  text-transform:uppercase;
  letter-spacing:.12em;
  font-size:.75rem;
  font-weight:900;
  color:var(--blue);
  margin:0 0 8px;
}
.hero h1,.page-title{
  color:var(--navy);
  letter-spacing:-.035em;
  line-height:1.05;
  margin:0 0 14px;
}
.hero h1{font-size:clamp(2.5rem,6vw,4.8rem)}
.hero p{max-width:760px;color:var(--muted);font-size:1.08rem}

.home-grid{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:20px;
  margin:34px 0 10px;
}
.home-card{
  background:#fff;
  border:1px solid var(--line);
  border-radius:16px;
  padding:24px;
  box-shadow:0 8px 24px rgba(31,59,100,.05);
}
.home-card .badge,.lesson-badge{
  display:inline-block;
  background:var(--sky);
  color:var(--blue);
  padding:5px 9px;
  border-radius:999px;
  font-size:.75rem;
  font-weight:900;
  text-transform:uppercase;
}
.home-card h2{color:var(--navy);margin:12px 0 8px;font-size:1.7rem}
.home-card p{color:var(--muted)}
.home-card a{
  display:inline-block;
  margin-top:8px;
  background:var(--navy);
  color:#fff;
  text-decoration:none;
  padding:10px 14px;
  border-radius:8px;
  font-weight:900;
}

.main{padding:42px 0 70px}
.lesson-overview{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:10px;
  margin:22px 0 34px;
}
.lesson-overview a{
  background:#fff;
  border:1px solid var(--line);
  color:var(--navy);
  text-decoration:none;
  padding:12px;
  border-radius:10px;
  font-weight:800;
  text-align:center;
}
.lesson-overview a:hover{border-color:var(--blue);background:var(--sky)}

.info-strip{
  background:#fff8d8;
  border-left:5px solid var(--yellow);
  padding:15px 17px;
  border-radius:8px;
  margin:18px 0 28px;
}
.material-card{
  display:flex;
  justify-content:space-between;
  gap:16px;
  align-items:center;
  background:#fff;
  border:1px solid var(--line);
  padding:17px;
  border-radius:12px;
  margin:18px 0 28px;
}
.material-card strong,.material-card small{display:block}
.material-card small{color:var(--muted)}
.material-card a{
  background:var(--blue);
  color:#fff;
  text-decoration:none;
  padding:9px 12px;
  border-radius:8px;
  font-weight:900;
  white-space:nowrap;
}

.lesson-card{
  background:var(--card);
  border:1px solid var(--line);
  border-radius:16px;
  padding:24px;
  margin:18px 0;
  box-shadow:0 6px 18px rgba(31,59,100,.04);
}
.lesson-heading{
  display:flex;
  gap:14px;
  align-items:center;
  margin-bottom:14px;
}
.lesson-number{
  width:48px;height:48px;
  border-radius:12px;
  background:var(--blue);
  color:#fff;
  display:grid;
  place-items:center;
  font-weight:900;
  font-size:1.2rem;
}
.lesson-heading h2,.lesson-heading h3{margin:0;color:var(--navy)}
.lesson-heading small{display:block;color:var(--muted);font-weight:800;text-transform:uppercase;letter-spacing:.06em}

.context,.goal,.result,.warning{
  padding:13px 15px;
  border-radius:8px;
  margin:12px 0 16px;
}
.context{background:#f2f6fa;border-left:5px solid var(--blue)}
.goal{background:#eef8e7;border-left:5px solid var(--green)}
.result{background:#edf8df;border-left:5px solid var(--green)}
.warning{background:#fff3e7;border-left:5px solid #e7902f}

.steps{
  display:grid;
  gap:0;
  margin-top:12px;
}
.steps>div{
  display:grid;
  grid-template-columns:44px 1fr;
  gap:12px;
  padding:14px 0;
  border-bottom:1px solid var(--line);
}
.steps>div:last-child{border-bottom:0}
.steps .step-no{
  width:36px;height:36px;
  border-radius:50%;
  background:var(--navy);
  color:#fff;
  display:grid;
  place-items:center;
  font-weight:900;
}
.steps b{color:var(--navy)}
.steps p{margin:3px 0 0;color:var(--muted)}
code{
  font-family:Consolas,monospace;
  background:#edf1f5;
  color:#12233c;
  padding:3px 5px;
  border-radius:4px;
}
.codeblock{
  display:block;
  padding:10px 12px;
  margin-top:6px;
  overflow:auto;
}

.task{
  margin-top:18px;
  border:2px dashed var(--blue);
  border-radius:12px;
  padding:17px;
  background:#fbfdff;
}
.task>strong{
  color:var(--blue);
  text-transform:uppercase;
  font-size:.8rem;
  letter-spacing:.08em;
}
.task p{margin:6px 0 12px}
.downloads{display:flex;gap:8px;flex-wrap:wrap}
.downloads a,.downloads button{
  border:0;
  background:var(--navy);
  color:#fff;
  text-decoration:none;
  padding:9px 11px;
  border-radius:8px;
  font-weight:900;
  cursor:pointer;
}
.downloads a.secondary{
  background:#eef2f6;
  color:var(--navy);
  border:1px solid var(--line);
}

.pre{
  background:#fff;
  border:1px solid var(--line);
  border-radius:14px;
  padding:20px;
  margin:18px 0 28px;
}
.pre h2{margin-top:0;color:var(--navy)}
.pre-grid{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:14px;
}
.pre-grid article{
  background:var(--soft);
  border-radius:10px;
  padding:15px;
}
.pre-grid h3{margin-top:0;color:var(--navy)}

.project{
  background:#eef5fb;
  border:1px solid #cfddeb;
  border-radius:16px;
  padding:24px;
  margin-top:30px;
}
.project h2,.project h3{color:var(--navy)}
.project-cases{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:10px;
}
.project-cases article{
  background:#fff;
  border:1px solid var(--line);
  border-radius:10px;
  padding:14px;
}
.project-cases article:last-child{grid-column:1/-1}
.project-cases h4{margin:0 0 4px;color:var(--blue)}
.project-cases p{margin:0;color:var(--muted)}
.project-steps{
  display:grid;
  grid-template-columns:1fr 1fr;
  gap:10px;
  margin-top:18px;
}
.project-steps>div{
  background:#fff;
  border:1px solid var(--line);
  border-radius:10px;
  padding:14px;
}
.project-steps b{color:var(--navy)}
.project-steps p{margin:4px 0 0;color:var(--muted)}

footer{
  background:#e9eef4;
  border-top:1px solid var(--line);
  padding:22px 0;
  color:var(--navy);
}
.footer-inner{display:flex;justify-content:space-between;gap:16px}
.footer-inner a{color:var(--blue);font-weight:900;text-decoration:none}

@media(max-width:760px){
  .home-grid,.pre-grid,.project-cases,.project-steps,.lesson-overview{grid-template-columns:1fr}
  .top-nav{display:none}
  .material-card{align-items:flex-start;flex-direction:column}
  .project-cases article:last-child{grid-column:auto}
}