body{
  margin:0;
  font-family:system-ui,sans-serif;
  background:#f4efe7;
  color:#222;
}

header{
  text-align:center;
  background:#2b1d18;
  color:white;
  padding:24px 12px;
}

header h1{
  margin:0;
}

nav{
  display:flex;
  flex-wrap:wrap;
  justify-content:center;
  gap:10px;
  padding:16px;
  background:white;
}

nav a{
  text-decoration:none;
  color:#2b1d18;
  border:1px solid #2b1d18;
  padding:8px 12px;
  border-radius:999px;
  font-weight:bold;
}

nav a.active{
  background:#2b1d18;
  color:white;
}

.quiz-box{
  max-width:760px;
  margin:24px auto;
  background:white;
  padding:24px;
  border-radius:16px;
  box-shadow:0 4px 16px #0002;
}

.status{
  display:flex;
  justify-content:space-between;
  font-weight:bold;
}

.progress{
  height:10px;
  background:#ddd;
  border-radius:999px;
  overflow:hidden;
  margin:16px 0;
}

#bar{
  height:100%;
  width:0%;
  background:#8b3a2f;
  transition:.3s;
}

#question{
  line-height:1.6;
}

#choices{
  display:grid;
  gap:12px;
  margin-top:20px;
}

.choice{
  border:none;
  background:#eee;
  padding:14px;
  border-radius:10px;
  font-size:16px;
  cursor:pointer;
}

.choice:hover{
  background:#ddd;
}

.correct{
  background:#b7e4c7 !important;
}

.wrong{
  background:#ffccd5 !important;
}

#result{
  font-weight:bold;
  min-height:28px;
}

.layout {
  display: grid;
  grid-template-columns: 220px minmax(0, 760px) 220px;
  gap: 20px;
  max-width: 1320px; /* 少し広げる */
  margin: 30px auto;
  padding: 0 16px;
  align-items: start;
}

.ad-side {
  min-height: 280px;
}

.quiz-box {
  width: 100%;
}

@media (max-width: 900px) {
  .layout {
    display: block;
  }

  .ad-side {
    margin: 20px 0;
  }
}

.ad-side:last-child {
  margin-left: 12px;
}