:root{
  --accent: #152733;
  --accent-hover: #87ceeb;
  --max-width: 1100px;
  --header-bleed-top: 160px;
  /* 中央寄せする sponsor-list の最大幅*/
  --sponsor-list-width: 900px;
}
/* =============================================================
   Global CSS Variables
   -------------------------------------------------------------
   NOTE: --header-bleed-top lifts the header upward (negative
   margin) while its value is added back into padding to keep
   inner content visually centered. Adjust with caution.
   ============================================================= */
:root{
  --accent: #152733;
  --accent-hover: #87ceeb;
  --max-width: 1100px;
  --header-bleed-top: 160px; /* Header negative offset (visual bleed) */
  --sponsor-list-width: 900px; /* Max width for sponsor logo column */
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family: "Hiragino Kaku Gothic ProN", Meiryo, "Yu Gothic", "Noto Sans JP", sans-serif;
  color:#222;
  background:#f7f8fb;
  line-height:1.6;
}
/* ========== Layout Container ========= */
.container{
  max-width:var(--max-width);
  margin:0 auto;
  padding:0 16px;
}
/* ========== Site Header ========= */
.site-header {
  position: relative;
  /* ヘッダーを上に引き上げる */
  margin-top: calc(-1 * var(--header-bleed-top));
  /* 引き上げた分だけ上パディングを増やす（コンテンツ位置は維持） */
  padding: calc(20rem + var(--header-bleed-top)) 0 8rem 0;
  background-image: url('images/thema.png');
  background-size: cover;
  background-position: center;
  color: #fff;
  min-height: 180px;
  display: flex;
  align-items: center;
  overflow: hidden;
}
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.2);
  z-index: 0;
}
.site-header .container {
  position: relative;
  z-index: 1;
}
.site-logo {
  width: 96px;
  height: auto;
  vertical-align: middle;
  margin-right: 1rem;
}
.site-title {
  margin: 0;
  font-size: clamp(1.25rem, 3vw, 4rem);
  line-height: 1.1;
  text-shadow: 0 2px 6px rgba(0,0,0,0.6);
}
.site-sub {
  margin: 0.25rem 0 0;
  opacity: 0.95;
  font-size: clamp(0.9rem, 2.2vw, 1rem);
  text-shadow: 0 1px 4px rgba(0,0,0,0.5);
}
.main-nav{background:var(--accent)}
.main-nav ul{list-style:none;margin:0;padding:0;display:flex;gap:8px;justify-content:center}
.main-nav a{display:block;padding:.8rem 1rem;color:#fff;text-decoration:none;font-weight:600}
.main-nav a:hover{background:var(--accent-hover);color:#012}
.section{padding:40px 0;border-bottom:1px solid rgba(0,0,0,0.05);text-align:center}
.section h2{margin:0 0 12px;font-size:1.25rem}
.btn{display:inline-block;background:var(--accent);color:#fff;padding:.6rem 1rem;border-radius:6px;text-decoration:none}
.btn:hover{background:var(--accent-hover);color:#012}

/* 2ボタン横並び用の行レイアウト */
.btn-row{
  display:flex;
  justify-content:center;
  gap:60px;          /* 間隔 */
  flex-wrap:wrap;    /* 画面が狭い時は折り返し */
  margin-top: 12px;
}
/* ENTRYのボタン幅を揃える */
.btn-row .btn{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 220px;  /* 同じ幅に固定（必要に応じて変更） */
  white-space: nowrap;                   /* 2行折返し防止 */
}

/* 注意書きのスタイル */
.notice-alert {
  color: #e74c3c;
  font-weight: bold;
  text-align: center;
  margin-top: 16px;
  font-size: 0.95rem;
}

.site-footer{padding:20px 0;background:#fff;border-top:1px solid rgba(0,0,0,0.06);text-align:center;margin-top:32px}

/* レスポンシブ */
@media (max-width:640px){
  /* Navigation: remove artificial line-height hack, ensure spacing */
  .main-nav ul{flex-direction:column;align-items:stretch;gap:4px;line-height:1.3;padding:8px 0;}
  .main-nav a{padding:.7rem 1.2rem;display:block;text-align:center;}

  .container{padding:0 12px}
  /* Header adjustments: neutralize large negative bleed and show more image */
  .site-header{margin-top:0;padding:6rem 0 3.5rem 0;min-height:260px;background-position:top center;}
  .site-title{font-size:1.55rem;}
  .site-sub{font-size:.95rem;}
}

/* Sponsor layout */
.sponsor-group{margin:24px 0}
.sponsor-list{
  display:flex;
  flex-direction: column;
  align-items: stretch;
  gap: 12px;
  max-width: var(--sponsor-list-width);
  margin: 12px auto 28px;
}
.sponsor-subtitle{margin:0 0 12px;font-size:1rem}
.sponsor-subtitle:not(:first-of-type){
  border-top:2px solid rgba(0,0,0,0.06);
  padding-top:18px;
  margin-top:34px; /* 少し余白を増やして区切りを強調 */
}

/* 主催：ロゴのみ中央寄せ＋サイズ可変 */
.sponsor-list--center{
  align-items: center;
}
.sponsor-logo-only{
  width: 540px;  /* ここを変えるとサイズ調整可能 */
  max-width: 100%;
  height: auto;
  padding: 2rem 0;
}
.sponsor-item{
  display:flex;
  align-items:center;
  gap:12px;
  height:150px;
  width: 100%;
  padding:8px 12px;
  text-decoration:none;
  color:inherit;
}
/* logo */
.sponsor-item img{
  width:auto;
  object-fit:contain;
  flex: 0 0 150px;
  max-width:150px;
}
/* name*/
.sponsor-name{
  flex: 1 1 auto;
  display:flex;
  align-items:center;
  justify-content:center;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
  font-size:1.65rem;
  font-weight:600;
}

@media (max-width:640px){
  .sponsor-item img{ flex-basis:80px; max-width:80px; height:80px; }
  .sponsor-name{ font-size:.95rem;}
  .sponsor-logo-only{
    width: 380px;
  }
}

/* PROGRAM */
.program-list{
  list-style:none;
  margin:16px auto 0;
  padding:0;
  max-width:900px;
  display:flex;
  flex-direction:column;
  gap:10px;
}
.program-list li{
  display:grid;
  grid-template-columns: 130px 1fr;
  gap:12px 16px;
  align-items:start;
  background:#fff;
  border:1px solid rgba(0,0,0,0.06);
  border-radius:10px;
  padding:10px 12px;
  box-shadow:0 1px 3px rgba(0,0,0,0.04);
  /* 追加: 浮き上がりアニメーション */
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease, background-color .18s ease;
  will-change: transform, box-shadow;
}
.program-list li:hover,
.program-list li:focus-within{
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.10);
  border-color: rgba(0,0,0,0.12);
}
/* 休憩行は浮かせない */
.program-list li.is-break:hover,
.program-list li.is-break:focus-within{
  transform:none;
  box-shadow:0 1px 3px rgba(0,0,0,0.04);
}
/* 動きが苦手な環境では移動を無効化 */
@media (prefers-reduced-motion: reduce){
  .program-list li{ transition: box-shadow .18s ease, border-color .18s ease; }
  .program-list li:hover,
  .program-list li:focus-within{ transform:none; }
}
.program-list time{
  font-weight:700;
  color:var(--accent);
  white-space:nowrap;
}
.session-title{ font-weight:600; }
.speaker{ color:#444; font-size:.95rem; margin-top:2px; }
.program-list .is-break{ background:#f6f8fb; }
.program-note{ margin-top:12px; font-size:.95rem; color:#333; }

/* narrow */
@media (max-width:640px){
  .program-list li{ grid-template-columns: 1fr; }
  .program-list time{ order:-1; }
}

/* セクション内に入れる標準イメージ（中央寄せ・レスポンシブ） */
.media-figure{
  margin: 14px auto 0;
  max-width: 400px;
}
.media-figure img{
  display:block;
  width:100%;
  height:auto;
}

/* ページ下部の全幅ビジュアル（コンテナ幅をはみ出して横いっぱい） */
.page-bottom-visual{
  margin: 14px auto 0;
  width: 400px;
}
.page-bottom-visual img{
  display:block;
  width:100%;
  height:auto;
  max-height: 420px;          /* 必要に応じて高さ調整 */
  object-fit: cover;
  object-position: center;
}
@media (max-width:640px){
  .media-figure{ max-width: 100%; }
  .page-bottom-visual img{ max-height: 280px; }
}