/* 共通変数 */
:root {
  --primary: #4a90e2;
  --secondary: #82cfff;
  --accent: #ffa726;
  --dark: #2c5f2d;
  --light-bg: #eef4fb;
}
* { margin:0; padding:0; box-sizing:border-box; }
body { font-family:"Segoe UI",sans-serif; background:var(--light-bg); color:#333; overflow-x:hidden; }

/* 背景アニメーション */
body::before {
  content:""; position:fixed; top:-20%; left:-20%; width:140%; height:140%;
  background: radial-gradient(circle at 30% 30%, rgba(74,144,226,0.2), transparent 70%),
              radial-gradient(circle at 70% 70%, rgba(130,207,255,0.2), transparent 70%);
  animation: bgMove 20s linear infinite;
  z-index:-2;
}
@keyframes bgMove {
  0%{transform:translate(0,0);}
  50%{transform:translate(20px,30px);}
  100%{transform:translate(0,0);}
}

/* 桜の花びら */
.petal {
  position: fixed;
  top: -10px;
  width: 20px;
  height: 20px;
  background: url('../images/toppage/sakura_petal.png') no-repeat center/contain;
  pointer-events: none;
  animation: fall linear infinite;
}
@keyframes fall {
  to {
    transform: translateY(100vh) rotate(360deg);
    opacity: 0;
  }
}

/* ヘッダー */
header.site-header {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  padding: 40px 20px; text-align:center; color:#fff; position:relative;
  box-shadow:0 4px 20px rgba(0,0,0,0.2);
  overflow: hidden;
}
header.site-header h1 {
  font-size:3.5rem; letter-spacing:4px; text-shadow:0 2px 12px rgba(0,0,0,0.5);
}
header.site-header p {
  margin-top:12px; font-size:1.125rem; opacity:0.9;
}
header.site-header::after {
  content:""; display:block; width:120px; height:6px;
  /* background:var(--accent); */
  margin:24px auto 0; 
  border-radius:3px;
  animation:expand 1s ease-out;
}
nav.site-nav {
  margin-top:32px; display:flex; justify-content:center; gap:32px; flex-wrap:wrap;
}
nav.site-nav a {
  position:relative; overflow:hidden; color:#fff; text-decoration:none;
  font-weight:600; padding:12px 20px; border:2px solid rgba(255,255,255,0.5);
  border-radius:8px; transition:transform .3s, background .3s;
  perspective:800px;
}
nav.site-nav a:hover {
  background:rgba(255,255,255,0.25); transform:translateY(-4px) rotateX(5deg);
}
nav.site-nav a:active {
  transform:translateY(-2px) rotateX(2deg);
}
nav.site-nav a::after {
  content:""; position:absolute; width:12px; height:12px; background:rgba(255,255,255,0.5);
  border-radius:50%; top:50%; left:50%; transform:translate(-50%,-50%) scale(0);
  transition:transform .6s ease-out, opacity .6s ease-out; opacity:0;
}
nav.site-nav a:active::after {
  transform:translate(-50%,-50%) scale(30); opacity:0.2; transition:none;
}

/* お知らせ黒板 */
.notice-board {
  background:var(--dark); color:#fff; max-width:900px; margin:-60px auto 60px;
  padding:32px; border-radius:12px; box-shadow:0 6px 24px rgba(0,0,0,0.3);
  font-family:"Courier New",monospace; position:relative; z-index:1;
  border:4px solid #333;
}
.notice-board::before {
  content:"📝 最新のお知らせ"; display:block; font-size:1.75rem;
  margin-bottom:16px; border-bottom:2px solid #fff; padding-bottom:8px;
}
.notice-board ul { list-style:none; }
.notice-board li {
  margin-bottom:12px; padding-left:32px; position:relative; font-size:1rem;
}
.notice-board li::before {
  content:"•"; position:absolute; left:0; top:0; color:var(--accent);
  font-size:1.5rem;
}

/* ヒーロー */
.hero {
  background: linear-gradient(135deg, rgba(0,80,160,0.8), rgba(0,140,220,0.8)),
              url('https://example.com/hero-electric.jpg') center/cover fixed no-repeat;
  height:160px; display:flex; align-items:center; justify-content:center;
  color:#fff; 
  text-shadow:0 2px 12px rgba(0,0,0,0.7); 
  /* border-radius:0 0 24px 24px; */
  margin-bottom:60px; opacity:0; transform:translateY(30px);
  transition:opacity .8s ease-out, transform .8s ease-out;
  position: relative; overflow: hidden;
}
.hero.visible { opacity:1; transform:translateY(0); }
.hero h2 {
  font-size:2.5rem; background:rgba(0,0,0,0.5); padding:20px 32px;
  border-radius:12px; line-height:1.3;
}

/* カードグリッド */
.section {
  max-width:1200px; margin:0 auto 80px; padding:0 20px;
}
.section h3 {
  font-size:2rem; color:var(--primary); margin-bottom:24px; position:relative;
}
.section h3::after {
  content:""; display:block; width:100px; height:6px;
  background:var(--accent); margin-top:12px; border-radius:3px;
}
.card-grid {
  display:grid; grid-template-columns:repeat(auto-fit,minmax(300px,1fr));
  gap:32px; margin-top:32px;
}
.card {
  background:#fff; padding:32px; border-radius:20px;
  box-shadow:0 8px 32px rgba(0,0,0,0.1); position:relative;
  overflow:hidden; opacity:0; transform:translateY(30px) rotateX(10deg);
  transform-origin:center bottom;
  transition:opacity .6s ease-out, transform .6s ease-out;
}
.card.visible {
  opacity:1; transform:translateY(0) rotateX(0);
}
.card::before {
  content:""; position:absolute; top:0; left:0; right:0; height:6px;
  background:linear-gradient(90deg,var(--primary),var(--secondary));
  transform:scaleX(0); transform-origin:left;
  transition:transform .5s ease-out;
}
.card:hover::before { transform:scaleX(1); }
.card:hover {
  transform:translateY(-8px) rotateX(0); box-shadow:0 16px 48px rgba(0,0,0,0.15);
}
.card h4 { font-size:1.4rem; margin-bottom:20px; color:#222; }
.card p { font-size:1rem; line-height:1.6; color:#555; }

/* フッター */
footer.site-footer {
  background:var(--primary); color:#fff; text-align:center;
  padding:40px 20px; font-size:0.875rem; border-top:6px solid var(--accent);
}

@keyframes expand { from{width:0;} to{width:100px;} }

/* モバイル */
@media(max-width:600px) {
  header.site-header h1 { font-size:2.2rem; }
  .notice-board { margin:-20px 12px 40px; padding:24px; }
  .hero { height:260px; }
  .hero h2 { font-size:1.75rem; padding:16px 24px; }
  .section h3 { font-size:1.75rem; }
  .card { padding:24px; border-radius:16px; }
  .card-grid { gap:24px; }
}