:root{
  --hawaii:#00A5C9;
  --hawaii-dark:#0077A0;
  --hawaii-deep:#005A7A;
  --hawaii-bg:#E8F7FB;
  --hawaii-bg2:#F4FBFD;
  --ink:#2B2B2B;
  --muted:#5A6A6F;
  --line:#C9E9F1;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:#fff;color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  line-height:1.55}
.wrap{max-width:1040px;margin:0 auto;padding:0 22px}
a{color:var(--hawaii-dark)}

.hero{background:var(--hawaii-dark);color:#fff;padding:56px 0 50px;
  box-shadow:0 4px 0 rgba(0,0,0,.06)}
.hero .kicker{font-size:.72rem;letter-spacing:.16em;text-transform:uppercase;
  color:#bfeaf5;font-weight:700;margin:0 0 10px}
.hero h1{margin:0 0 12px;font-size:2.6rem;font-weight:800;line-height:1.1}
.hero h1 span{color:#7fdcef}
.hero .lead{margin:0 0 16px;max-width:66ch;color:#e6f7fb;font-size:1.05rem}
.hero .lead b{color:#fff}
.hero .author{margin:0;font-size:.9rem;color:#bfeaf5}

main{padding:34px 0 24px}
.intro{display:flex;flex-wrap:wrap;gap:14px;margin:0 0 30px}
.intro-item{display:flex;align-items:center;gap:10px;background:var(--hawaii-bg);
  border:1px solid var(--line);border-radius:12px;padding:12px 18px;font-weight:600;
  color:var(--hawaii-deep)}
.intro-item .intro-n{font-size:1.5rem;font-weight:800;color:var(--hawaii-dark)}

.section-title{font-size:.8rem;letter-spacing:.14em;text-transform:uppercase;
  font-weight:800;color:var(--muted);margin:0 0 14px}

.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:18px;
  margin:0 0 10px}
.lec{display:flex;flex-direction:column;border:1px solid var(--line);border-radius:14px;
  overflow:hidden;background:#fff;box-shadow:0 1px 0 rgba(0,0,0,.03);transition:box-shadow .15s,transform .15s}
.lec:hover{box-shadow:0 8px 24px rgba(0,90,122,.14);transform:translateY(-2px)}
.lec-open{display:block;text-decoration:none;color:inherit;padding:20px 20px 18px;flex:1 1 auto}
.lec-num{display:inline-flex;align-items:center;justify-content:center;width:40px;height:40px;
  border-radius:10px;background:var(--hawaii);color:#fff;font-weight:800;font-size:1.15rem;
  margin:0 0 12px}
.lec-title{display:block;font-size:1.16rem;font-weight:800;color:var(--hawaii-deep);
  line-height:1.25;margin:0 0 12px}
.lec-go{display:block;font-size:.85rem;font-weight:700;color:var(--hawaii-dark)}
.lec:hover .lec-go{text-decoration:underline}
.lec-dl{display:flex;gap:8px;padding:0 16px 16px;flex-wrap:wrap}
.lec-dl .dl{display:inline-flex;align-items:center;gap:6px;flex:1 1 auto;justify-content:center;
  text-decoration:none;font-size:.85rem;font-weight:700;color:var(--hawaii-dark);
  background:var(--hawaii-bg2);border:1px solid var(--line);border-radius:9px;padding:8px 10px;
  white-space:nowrap}
.lec-dl .dl:hover{background:var(--hawaii-bg);border-color:var(--hawaii)}
.lec-dl .ico{font-size:.95rem}

.foot{border-top:1px solid var(--line);margin-top:24px;padding:24px 0 40px;
  color:var(--muted);font-size:.85rem}

@media (max-width:560px){
  .hero{padding:40px 0 36px}
  .hero h1{font-size:2rem}
  .grid{grid-template-columns:1fr}
}