*,
*::before,
*::after {
  box-sizing: border-box;
}
html, body {
  margin: 0;
  padding: 0;
  font-family: "Noto Sans JP", sans-serif;
  color: #222;
  background: #fff;
  line-height: 1.7;
}
img {
  max-width: 100%;
  display: block;
}
a {
  color: inherit;
  text-decoration: none;
}
ul {
  margin: 0;
  padding: 0;
  list-style: none;
}
:root {
  --primary: #004c97;
  --primary-light: #1a6bcf;
  --accent: #e60033;
  --gray-bg: #f7f7f7;
  --dark: #1a1a1a;
}
.container {
  width: min(1200px, 90%);
  margin: auto;
}
.section {
  padding: 80px 0;
}
.section-alt {
  background: var(--gray-bg);
  padding: 80px 0;
}
.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 20px;
  position: relative;
}
.section-title::after {
  content: "";
  width: 60px;
  height: 4px;
  background: var(--primary);
  display: block;
  margin-top: 10px;
}
.section-title.center {
  text-align: center;
}
.section-title.center::after {
  margin-left: auto;
  margin-right: auto;
}
.two-column {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
}
.rounded {
  border-radius: 12px;
  overflow: hidden;
}
.header {
  background: #fff;
  border-bottom: 1px solid #eee;
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 0;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  color: var(--primary);
}
.nav-list {
  display: flex;
  gap: 30px;
  align-items: center;
}
.nav-cta {
  padding: 10px 18px;
  background: var(--primary);
  color: #fff;
  border-radius: 6px;
  font-weight: 600;
}
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
}
.nav-toggle span {
  width: 28px;
  height: 3px;
  background: var(--primary);
  border-radius: 3px;
}
.hero {
  background: linear-gradient(135deg, #eaf3ff, #ffffff);
  padding: 80px 0;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}
.hero-text h1 {
  font-size: 2.8rem;
  font-weight: 700;
  line-height: 1.3;
}
.hero-text h1 span {
  color: var(--primary);
}
.hero-buttons {
  margin-top: 25px;
  display: flex;
  gap: 20px;
}
.btn {
  padding: 12px 24px;
  border-radius: 6px;
  font-weight: 600;
  display: inline-block;
  text-align: center;
}
.btn.primary {
  background: var(--primary);
  color: #fff;
}
.btn.primary:hover {
  background: var(--primary-light);
}
.btn.ghost {
  border: 2px solid var(--primary);
  color: var(--primary);
}
.btn.ghost:hover {
  background: var(--primary);
  color: #fff;
}
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 30px;
  margin-top: 40px;
}
.card {
  background: #fff;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  transition: transform .2s, box-shadow .2s;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.12);
}
.card h3 {
  font-size: 1.3rem;
  margin: 15px;
}
.card p {
  margin: 0 15px 20px;
  color: #555;
}
.news-list {
  display: grid;
  gap: 20px;
  margin-top: 30px;
}
.news-item {
  padding: 20px;
  background: #fff;
  border-radius: 10px;
  border-left: 6px solid var(--primary);
  display: block;
  transition: background .2s;
}
.news-item:hover {
  background: #f0f7ff;
}
.news-item time {
  font-size: 0.9rem;
  color: #666;
}
.tag {
  display: inline-block;
  padding: 3px 8px;
  border-radius: 4px;
  font-size: 0.75rem;
  margin-left: 10px;
  color: #fff;
}
.tag.event { background: var(--primary); }
.tag.important { background: var(--accent); }
.tag.campus { background: #00a381; }
.entry-form {
  background: #fff;
  padding: 30px;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}
.entry-form label {
  display: block;
  margin-bottom: 15px;
  font-weight: 600;
}
.entry-form input,
.entry-form select {
  width: 100%;
  padding: 10px;
  margin-top: 6px;
  border: 1px solid #ccc;
  border-radius: 6px;
}
.btn.full {
  width: 100%;
  margin-top: 10px;
}
.map {
  background: #ddd;
  height: 250px;
  border-radius: 12px;
  display: flex;
  justify-content: center;
  align-items: center;
}
.footer {
  background: var(--dark);
  color: #fff;
  padding: 50px 0;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 40px;
}
.footer-links li {
  margin-bottom: 10px;
}
.footer-links a {
  color: #fff;
  opacity: 0.8;
}
.footer-links a:hover {
  opacity: 1;
}
.footer-bottom {
  text-align: center;
  margin-top: 40px;
  opacity: 0.7;
}
@media (max-width: 900px) {
  .two-column {
    grid-template-columns: 1fr;
  }
  .hero-inner {
    grid-template-columns: 1fr;
  }
  .nav-list {
    display: none;
    flex-direction: column;
    gap: 20px;
    background: #fff;
    padding: 20px;
    position: absolute;
    right: 20px;
    top: 70px;
    width: 200px;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  }
  .nav-toggle {
    display: flex;
  }
  .nav.open .nav-list {
    display: flex;
  }
}

/* =========================================================
   Animation Container & Base Items (洗練されたアニメーション)
========================================================= */
#season-animation {
  position: fixed;
  pointer-events: none;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  z-index: 9999;
  perspective: 1000px; /* 3D効果で花びらや葉を立体的に回転させる */
}

.season-item {
  position: absolute;
  top: -30px;
  will-change: transform, opacity;
}

/* --- 1. 桜の花びら (petal) --- */
.petal {
  width: 14px;
  height: 14px;
  background: #ffb7d5;
  border-radius: 150% 0 150% 150%; /* より花びらに近い非対称な形 */
  box-shadow: 0 0 4px rgba(255, 182, 193, 0.5);
  animation: advancedSwayFall 9s ease-in-out infinite;
}

/* --- 2. 新緑・紅葉の葉 (leaf) --- */
.leaf {
  width: 16px;
  height: 11px;
  background: var(--primary); /* テーマに連動した色（5月緑、秋は茶・橙） */
  border-radius: 100% 0 100% 0;
  animation: advancedLeafFall 11s ease-in-out infinite;
}

/* --- 3. 雪 (snow) --- */
.snow {
  width: 6px;
  height: 6px;
  background: #ffffff;
  border-radius: 50%;
  opacity: 0.8;
  filter: blur(0.5px);
  box-shadow: 0 0 6px 1px rgba(255, 255, 255, 0.8);
  animation: advancedSnowFall 7s linear infinite;
}

/* --- 4. 夏のきらめき (sparkle)：自動浮遊を非表示に修正 --- */
.season-item.sparkle {
  display: none; /* 自動で湧き出るきらめき（ホタル）を消去 */
  background: #fffbbf; 
  border-radius: 50%;
  box-shadow: 0 0 12px 6px #ffeb3b, 0 0 24px 12px rgba(255, 235, 59, 0.4);
  animation: summerFirefly 5s ease-in-out infinite;
}


/* =========================================================
   Advanced Keyframes (動きの物理シミュレーション)
========================================================= */

/* 【桜】 左右に美しく蛇行しながら、3D空間をくるくる回って落ちる */
@keyframes advancedSwayFall {
  0% {
    transform: translateY(0) translateX(0) rotateX(0deg) rotateY(0deg) rotateZ(0deg);
    opacity: 0;
  }
  10% { opacity: 0.9; }
  30% { transform: translateY(30vh) translateX(40px) rotateX(120deg) rotateY(60deg) rotateZ(45deg); }
  60% { transform: translateY(60vh) translateX(-30px) rotateX(240deg) rotateY(180deg) rotateZ(135deg); }
  90% { opacity: 0.9; }
  100% {
    transform: translateY(105vh) translateX(50px) rotateX(360deg) rotateY(360deg) rotateZ(270deg);
    opacity: 0;
  }
}

/* 【葉】 重さがあるため、風に煽られ不規則に大きな弧を描いてハラハラと落ちる */
@keyframes advancedLeafFall {
  0% {
    transform: translateY(0) translateX(0) rotate(0deg) scaleX(1);
    opacity: 0;
  }
  15% { opacity: 0.8; }
  40% { transform: translateY(40vh) translateX(-60px) rotate(180deg) scaleX(0.4); }
  75% { transform: translateY(75vh) translateX(50px) rotate(320deg) scaleX(1); }
  85% { opacity: 0.8; }
  100% {
    transform: translateY(105vh) translateX(-20px) rotate(450deg) scaleX(0.6);
    opacity: 0;
  }
}

/* 【雪】 微妙に左右に揺れながら、リアリティのある速度で優しく落ちる */
@keyframes advancedSnowFall {
  0% {
    transform: translateY(0) translateX(0);
    opacity: 0;
  }
  10% { opacity: 0.8; }
  50% { transform: translateY(50vh) translateX(15px); }
  90% { opacity: 0.8; }
  100% {
    transform: translateY(105vh) translateX(-10px);
    opacity: 0;
  }
}

/* 【夏】 その場で呼吸するように明滅しながら、風に流されて少し浮遊する動き */
@keyframes summerFirefly {
  0% {
    transform: scale(0) translate(0, 0);
    opacity: 0;
  }
  20% {
    transform: scale(1) translate(calc(var(--drift) * 0.3), -20px);
    opacity: 1;
  }
  40% {
    transform: scale(0.5) translate(calc(var(--drift) * 0.6), -40px);
    opacity: 0.3; /* 一瞬消えそうになる */
  }
  60% {
    transform: scale(1.2) translate(calc(var(--drift) * 0.4), -60px);
    opacity: 1; /* 再び強く光る */
  }
  80% {
    opacity: 0.8;
  }
  100% {
    transform: scale(0) translate(var(--drift), -90px);
    opacity: 0;
  }
}

/* =========================================================
   Month Theme (12ヶ月テーマ)
========================================================= */

/* 1月：正月（寒色＋雪） */
.theme-jan {
  --primary: #3366cc;
  --primary-light: #5c8cff;
  --accent: #cc0000;
  --gray-bg: #eef4ff;
  background: linear-gradient(135deg, #dbe7ff, #ffffff);
}

/* 2月：雪深い冬（青白） */
.theme-feb {
  --primary: #6699ff;
  --primary-light: #88b3ff;
  --accent: #003399;
  --gray-bg: #f0f6ff;
  background: linear-gradient(135deg, #e0eaff, #ffffff);
}

/* 3月：早春（薄ピンク） */
.theme-mar {
  --primary: #ff9ecb;
  --primary-light: #ffb7d9;
  --accent: #ff6fa8;
  --gray-bg: #fff2f7;
  background: linear-gradient(135deg, #ffe6f2, #ffffff);
}

/* 4月：桜満開（濃いピンク） */
.theme-apr {
  --primary: #ff6fa8;
  --primary-light: #ff8fbd;
  --accent: #ff3f8e;
  --gray-bg: #ffeaf3;
  background: linear-gradient(135deg, #ffe3ef, #ffffff);
}

/* 5月：新緑（グリーン） */
.theme-may {
  --primary: #4caf50;
  --primary-light: #6ecf72;
  --accent: #2e7d32;
  --gray-bg: #e8f5e9;
  background: linear-gradient(135deg, #e8f5e9, #ffffff);
}

/* 6月：初夏（アクアブルー） */
.theme-jun {
  --primary: #00aaff;
  --primary-light: #33bbff;
  --accent: #0077aa;
  --gray-bg: #e0f7ff;
  background: linear-gradient(135deg, #ccf2ff, #ffffff);
}

/* 7月：夏本番（濃い青） */
.theme-jul {
  --primary: #0088ff;
  --primary-light: #339dff;
  --accent: #005fcc;
  --gray-bg: #e6f3ff;
  background: linear-gradient(135deg, #b3e5ff, #ffffff);
}

/* 8月：夏の終わり（深い青） */
.theme-aug {
  --primary: #0066cc;
  --primary-light: #3388dd;
  --accent: #004c99;
  --gray-bg: #e3f1ff;
  background: linear-gradient(135deg, #d0ecff, #ffffff);
}

/* 9月：初秋（オレンジ） */
.theme-sep {
  --primary: #d97a00;
  --primary-light: #ff9c33;
  --accent: #b85f00;
  --gray-bg: #fff3e0;
  background: linear-gradient(135deg, #ffe0b3, #ffffff);
}

/* 10月：紅葉（濃いオレンジ） */
.theme-oct {
  --primary: #cc5500;
  --primary-light: #ff7a26;
  --accent: #993f00;
  --gray-bg: #ffe8d6;
  background: linear-gradient(135deg, #ffd9b3, #ffffff);
}

/* 11月：晩秋（茶色） */
.theme-nov {
  --primary: #b34700;
  --primary-light: #d96b26;
  --accent: #8c3900;
  --gray-bg: #fff0e0;
  background: linear-gradient(135deg, #ffe6cc, #ffffff);
}

/* 12月：クリスマス（赤＋雪） */
.theme-dec {
  --primary: #cc0000;
  --primary-light: #ff3333;
  --accent: #0066cc;
  --gray-bg: #fff0f0;
  background: linear-gradient(135deg, #ffe5e5, #ffffff);
}

/* =========================================================
   【新規追加】クリック花火（Firework Particle）
========================================================= */
.firework-particle {
  position: fixed;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  pointer-events: none;
  z-index: 10000;
  will-change: transform, opacity;
  animation: fireworkExplode 1.2s cubic-bezier(0.1, 0.8, 0.3, 1) forwards;
}

@keyframes fireworkExplode {
  0% {
    transform: translate(-50%, -50%) scale(1);
    opacity: 1;
  }
  80% {
    opacity: 0.9;
  }
  100% {
    /* 指定された方向に飛び散りつつ、少し下に落ちる（重力表現） */
    transform: translate(calc(-50% + var(--tx)), calc(-50% + var(--ty) + 40px)) scale(0.2);
    opacity: 0;
  }
}
/* ===============================
   TOP SLIDER（横スライド＋ボタン付き）
================================= */
.top-slider {
  width: 100%;
  height: 60vh;
  overflow: hidden;
  position: relative;
}

/* 横に並べるトラック */
.slider-track {
  display: flex;
  height: 100%;
  transition: transform 0.6s ease;
}

/* 各スライド */
.slide {
  width: 100%;
  height: 100%;
  flex-shrink: 0;
}

/* =========================================================
   一番上のスライダー：絶対に見切れない＆隙間を作らない設定
========================================================= */
.top-slider {
  width: 100%;
  height: auto;       /* ← 高さを固定せず、画像の高さに自動で合わせる */
  overflow: hidden;
  position: relative;
}

.top-slider .slide img {
  width: 100%;
  height: auto;       /* ← 縦横比を100%保ったまま拡大縮小する */
  object-fit: normal; /* ← 無理な切り抜きを解除 */
}

/* 左右ボタンの位置を画像中央に自動調整（高さが変わるためパーセント指定に） */
.top-slider .slider-btn {
  top: 50%;
  transform: translateY(-50%);
}

/* 左右ボタン */
.slider-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(0,0,0,0.4);
  color: #fff;
  border: none;
  font-size: 2rem;
  padding: 10px 18px;
  cursor: pointer;
  border-radius: 6px;
  z-index: 10;
  transition: background 0.3s;
}

.slider-btn.prev {
  left: 20px;
}

.slider-btn.next {
  right: 20px;
}

.slider-btn:hover {
  background: rgba(0,0,0,0.6);
}

/* スマホ対応 */
@media (max-width: 600px) {
  .top-slider {
    height: 40vh;
  }
  .slider-btn {
    font-size: 1.5rem;
    padding: 8px 14px;
  }
}
/* --- 学科ラインナップの画像をきれいに統一する設定 --- */
.card img {
  width: 100%;
  height: 200px;        /* ← 画像の高さを一律 200px に固定（お好みで調整してください） */
  object-fit: cover;    /* ← これを入れると、画像が縦横に潰れず、枠に合わせて綺麗にトリミングされます */
}