@charset "UTF-8";

:root{
  --bg: #ffffff;
  --card: #e2e2e2;
  --text: #0B2447;
  --muted:#0B2447;
  --brand: #5aa2ff;
  --ring: #7db0ff66;
  --radius: 16px;

}

/* ダーク/ライト自動切替 */
@media (prefers-color-scheme: light){
  :root{
    --bg: #f7f9ff;
    --card: #ffffff;
    --text: #0B2447;
    --muted: #5a647e;
    --brand: #2b6cff;
    --ring: #2b6cff22;
  }
}

html,body{
  height:100%;
  background: radial-gradient(1200px 800px at 10% -10%),
              radial-gradient(900px 600px at 110% 10%),
              var(--bg);
  color:var(--text);
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic UI", "Meiryo", sans-serif;
  margin:0;
}

.wrapper{
  max-width: 880px;
  margin: clamp(24px, 6vw, 64px) auto;
  padding: 30px 20px;
}

.heading{
  margin: 0 0 20px;
  letter-spacing: .02em;
  font-weight: 800;
  font-size: clamp(28px, 4.5vw, 40px);
}

.lead{
  margin: 0 0 28px;
  color: var(--muted);
  font-size: clamp(14px, 2.4vw, 16px);
}

.faq{
  background: color-mix(in oklab, var(--card) 92%, transparent);
  border: 1px solid color-mix(in oklab, var(--brand) 18%, transparent);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

/* 各Q&A行 */
details{
  border-top: 1px solid color-mix(in oklab, var(--brand) 14%, transparent);
}
details:first-of-type{
  border-top: none;
}

summary{
  list-style: none;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 14px;
  padding: 18px 20px;
  cursor: pointer;
  font-weight: 700;
  position: relative;
  transition: background .25s ease;
}
summary:hover{
  background: color-mix(in oklab, var(--brand) 12%, transparent);
}
summary:focus-visible{
  outline: 3px solid var(--ring);
  outline-offset: 2px;
  border-radius: 10px;
}

/* Qラベル */
.qtag{
  display:inline-grid;
  place-items:center;
  width: 28px; height: 28px;
  border-radius: 10px;
  background: color-mix(in oklab, var(--brand) 30%, #0B2447 0%);
  color: white;
  font-weight: 800;
  font-size: 14px;
  box-shadow: inset 0 -2px 0 rgba(0,0,0,.2);
}

/* プラス/マイナスのアイコン */
.icon{
  position: relative;
  width: 18px; height: 18px;
}
.icon::before,
.icon::after{
  content:"";
  position:absolute;
  inset:0;
  margin:auto;
  width: 18px; height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform .25s ease, opacity .2s ease;
}
.icon::after{
  transform: rotate(90deg);
}
details[open] .icon::after{
  transform: rotate(0deg);
  opacity: 0;
}

/* 回答本文 */
.answer{
  padding: 0 20px 20px 62px;
  color: var(--muted);
}
.answer p{
  margin: 0;
}

/* 区切り線 */
details + details summary{
  border-top: 1px solid color-mix(in oklab, var(--brand) 10%, transparent);
}

/* スマホ調整 */
@media (max-width: 768px){
  .answer{
    padding-left: 20px;
  }
  summary{
    grid-template-columns: 1fr auto;
  }
  .qtag{ display:none; }
}

@media (max-width: 480px){
  .answer{
    padding-left: 0;
  }
  summary{
    grid-template-columns: 1fr auto;
  }
  .qtag{ display:none; }
}