:root{
  --navy:#2c3e57;
  --slate:#4a5a72;
  --bg:#eef1f5;
  --card:rgba(255,255,255,.72);
  --accent:#3a6ea5;
  --ink:#2b3547;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:Georgia,"Times New Roman",serif;color:var(--ink);background:var(--bg);line-height:1.7}
.wrap{max-width:1080px;margin:0 auto;padding:0 22px}

/* header */
header.site{background:#fff;border-bottom:1px solid #dde3ea;position:sticky;top:0;z-index:20}
header .wrap{display:flex;flex-direction:column;align-items:center;gap:10px;padding:16px 22px}
.brand{font-size:1.5rem;color:var(--navy);text-decoration:none;letter-spacing:.01em}
header nav{display:flex;flex-wrap:wrap;justify-content:center;gap:10px 20px}
header nav a{color:var(--slate);text-decoration:none;font-size:.92rem;padding:2px 0;border-bottom:2px solid transparent}
header nav a:hover{color:var(--accent);border-bottom-color:var(--accent)}

/* hero */
.hero{background:linear-gradient(135deg,#2c3e57,#3a6ea5);color:#fff;text-align:center;padding:90px 22px}
.hero h1{font-size:2.8rem;font-weight:400;margin-bottom:14px}
.hero .tag{font-size:1.25rem;font-style:italic;opacity:.92}

/* topics */
main{padding:20px 0 40px}
.topic{padding:34px 22px;display:flex;justify-content:center}
.topic:nth-child(even){background:#e6ebf1}
.card{
  background:var(--card);
  backdrop-filter:blur(4px);
  max-width:760px;width:100%;
  padding:38px 40px;border-radius:8px;
  box-shadow:0 8px 30px rgba(44,62,87,.10);
  border:1px solid rgba(255,255,255,.6);
}
.card h2{font-family:"Arial Black","Helvetica Neue",Arial,sans-serif;font-weight:800;font-size:2.3rem;letter-spacing:-.01em;color:var(--navy);text-transform:uppercase;margin-bottom:20px}
.card p{color:var(--slate);margin-bottom:15px}

/* footer */
.site-foot{background:var(--navy);color:#cdd6e2;text-align:center;padding:34px 22px}
.site-foot .fname{font-size:1.25rem;color:#fff;margin-bottom:8px}
.site-foot a{color:#a9c6e6;text-decoration:none}
.site-foot .tf{margin-top:14px;font-size:.85rem;opacity:.7}

@media (max-width:640px){
  .hero h1{font-size:2rem}.hero{padding:60px 20px}
  .card{padding:26px 22px}.card h2{font-size:1.7rem}
  header nav{gap:8px 14px}
}