/* ============ Base ============ */
*{ box-sizing: border-box; }

body{
  font-family: Arial, sans-serif;
  background: #f7f7f7;
  margin: 0;
  color: #111;
  line-height: 1.6;
}

a{ color: inherit; text-decoration: none; }

/* ============ Hero (center + pop up) ============ */
.hero{
  text-align: center;
  padding: 54px 16px 10px;
}

.hero-title{
  margin: 0;
  font-size: 54px;
  letter-spacing: .2px;
  animation: popIn .6s ease-out both;
}

.hero-sub{
  margin: 10px 0 0;
  font-size: 18px;
  color: #555;
  animation: popIn .7s ease-out both;
  animation-delay: .08s;
}

@keyframes popIn{
  0%   { opacity: 0; transform: translateY(14px) scale(.97); }
  70%  { opacity: 1; transform: translateY(-2px) scale(1.01); }
  100% { opacity: 1; transform: translateY(0) scale(1); }
}

/* ============ Topics grid ============ */
.topics{
  max-width: 1100px;
  margin: 26px auto 56px;
  padding: 0 16px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
}

.card{
  display: block;
  background: #fff;
  border-radius: 18px;
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(0,0,0,.08);
  transform: translateZ(0);
  transition: transform .25s ease, box-shadow .25s ease;
}

.card img{
  width: 100%;
  height: 180px;
  object-fit: cover;
  display: block;
}

.pad{
  padding: 14px 16px 16px;
  text-align: center;
}

.title{
  margin: 0;
  font-weight: 800;
  font-size: 22px;
}

.sub{
  margin: 10px 0 0;
  font-size: 16px;
  color: #444;
}

.card:hover{
  transform: scale(1.05);
  box-shadow: 0 16px 40px rgba(0,0,0,.16);
}

/* mobile tweak */
@media (max-width: 520px){
  .hero-title{ font-size: 40px; }
  .card img{ height: 165px; }
}