/* ========== Conference Site Spring Theme (Tokyo Sakura Season) ==========
   Light, airy palette with subtle sakura accents.
   Tweak the CSS variables in :root to adjust the theme easily.
*/
:root{
  --bg: #fff7fb;          /* ページ背景 */
  --bg-soft: #fff0f6;     /* petal veil */
  --card: #ffffff;        /* 各種カード背景 */
  --text: #1f2430;        /* readable dark */
  --muted: #5b6475;       /* calm gray */
  --accent: #e886a8;      /* sakura pink */
  --accent-2: #ffd8e5;    /* petal pink */
  --link: #cb0658;        /* link color */
  --shadow: rgba(17, 20, 39, 0.08);
  --radius: 14px;
  --maxw: 1000px;
  --space: 18px;
}

*{box-sizing:border-box;}
html,body{
  margin:0; padding:0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
  background:
    radial-gradient(1000px 400px at 90% -50%, rgba(232,134,168,0.18), transparent 60%),
    radial-gradient(800px 500px at -30% 0%, rgba(255,216,229,0.35), transparent 60%),
    var(--bg);
  color: var(--text);
  scroll-padding-top: 80px;  /* 例: 100px */
}

.container{width: min(95%, var(--maxw)); margin: 0 auto;}
.title-container{width: 100%; margin: 0 auto; background:#fff}

header.site {
  position: fixed;       /* always on top */
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;          /* ensure above other content */
  background:
    linear-gradient(180deg, rgba(255,255,255,0.95), rgba(255,255,255,0.85));
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(0,0,0,0.06);
}

.nav-container {
  width: 100%;            /* full width inside sticky header */
  max-width: none;
  margin: 0 auto;
  padding: 16px 16px;      /* vertical and horizontal padding */
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-sizing: border-box;
}

/* Large screens */
@media (min-width: 1024px) {
  .nav-container {
    width: 90%;
    padding: 20px 24px;  /* taller nav on desktop */
  }
}

/* Medium screens */
@media (max-width: 1023px) {
  .nav-container {
    width: 95%;
    padding: 16px 16px;  /* medium height */
  }
}

/* Mobile screens */
@media (max-width: 800px) {
  .nav-container {
    width: 100%;
    padding: 12px 8px;   /* smaller vertical padding for mobile */
  }
}

/* ---- Hero Background Image (Optional) -----------------------------------
   To use a custom hero image on any page, set:
     <div class="hero" style="--hero-image: url('images/your-hero.jpg')">
   By default, it falls back to the gradient background.
---------------------------------------------------------------------------*/
.hero { 
  position: relative; 
  overflow: hidden;
}
.hero > .container { 
  position: relative; 
  z-index: 2; 
}

.hero::before {
  content:""; 
  position:absolute; 
  inset:0;
  background-image: var(--hero-image, none); /* This is where the background image is applied */
  background-size: cover; 
  background-position: center;
  filter: saturate(1.05) contrast(0.98);
  z-index: 0;
}

.hero::after {
  content:""; 
  position:absolute; 
  inset:0; 
  z-index:1;
  background: radial-gradient(80% 60% at 20% -10%, rgba(255,255,255,0.85), transparent 80%),
    linear-gradient(180deg, rgba(255,255,255,0.75), rgba(255,255,255,0.35));
  pointer-events:none;
  opacity: var(--hero-overlay, 0.85); /* Overlay opacity set here */
}

.hero .credit {
  position: absolute;        /* Keep it in place within the hero */
  right: .5rem;              /* Position it at the bottom-right */
  bottom: .5rem;
  z-index: 3;                /* Ensure it’s above the background and overlay */
  display: inline-block;     /* Keeps it inline but allows block-level behavior */
  max-width: min(70ch, 92vw);/* Ensure it doesn't exceed the viewport width */
  padding: .25rem .5rem;
  border-radius: .25rem;
  background: rgba(0,0,0,.2); /* Slightly darker background for readability */
  color: #fff;
  font: 8px/1.3 system-ui, -apple-system, Segoe UI, Roboto, sans-serif; /* Increased font size and fallback fonts */
  text-decoration: none;     /* No underline by default */
  visibility: visible;       /* Make sure it’s not hidden */
  opacity: 1;                /* Ensure full visibility */
  pointer-events: auto;      /* Ensure the link is clickable */
}

.hero .credit:hover,
.hero .credit:focus {
  text-decoration: underline; /* Underline on hover/focus */
  outline: none;              /* Remove default outline on focus */
}

/* Optional: Add responsive design to ensure it's readable on smaller screens */
@media screen and (max-width: 768px) {
  .hero .credit {
    font-size: 10px;           /* Reduce font size on smaller screens */
    padding: .2rem .4rem;      /* Adjust padding for smaller screens */
  }
}

/* Make the hero *tall enough* so image is always visible */
.heroindex{
  position: relative;
  min-height: clamp(450px, 60vh, 720px); /* guarantee some image area */
  padding-top: 440px; /* avoid fixed header overlap */
  overflow: hidden;
}

/* Background image (kept from your existing setup) */
.heroindex::before{
  content:"";
  position:absolute; inset:0;
  background-image: var(--heroindex-image, none);
  background-size: cover;
  background-position: var(--heroindex-pos, center center);
  z-index: 0;
}

/* Make overlay lighter at the bottom so image shows there */
.heroindex::after{
  content:"";
  position:absolute; inset:0; z-index:1;
  /* strong at top, fades toward bottom */
  background:
    linear-gradient(
      to bottom,
      rgba(255,255,255, calc(var(--heroindex-overlay, .2) + .15)) 0%,
      rgba(255,255,255, calc(var(--heroindex-overlay, .2))) 40%,
      rgba(255,255,255, calc(var(--heroindex-overlay, .2) * .4)) 75%,
      rgba(255,255,255, 0) 100%
    );
  pointer-events:none;
}

.heroindex .credit {
  position: absolute;        /* Keep it in place within the hero */
  right: .5rem;              /* Position it at the bottom-right */
  bottom: .5rem;
  z-index: 3;                /* Ensure it’s above the background and overlay */
  display: inline-block;     /* Keeps it inline but allows block-level behavior */
  max-width: min(70ch, 92vw);/* Ensure it doesn't exceed the viewport width */
  padding: .25rem .5rem;
  border-radius: .25rem;
  background: rgba(0,0,0,.2); /* Slightly darker background for readability */
  color: #fff;
  font: 8px/1.3 system-ui, -apple-system, Segoe UI, Roboto, sans-serif; /* Increased font size and fallback fonts */
  text-decoration: none;     /* No underline by default */
  visibility: visible;       /* Make sure it’s not hidden */
  opacity: 1;                /* Ensure full visibility */
  pointer-events: auto;      /* Ensure the link is clickable */
}

.heroindex .credit:hover,
.heroindex .credit:focus {
  text-decoration: underline; /* Underline on hover/focus */
  outline: none;              /* Remove default outline on focus */
}

/* Optional: Add responsive design to ensure it's readable on smaller screens */
@media screen and (max-width: 768px) {
  .heroindex .credit {
    font-size: 10px;           /* Reduce font size on smaller screens */
    padding: .2rem .4rem;      /* Adjust padding for smaller screens */
  }
}

/* Bottom-anchor the title panel */
.heroindex-inner{
  position: relative;
  z-index: 2;
  height: 100%;
  display: grid;
  align-content: end; /* push content to the bottom */
  padding-bottom: clamp(16px, 4vh, 36px); /* breathing room above bottom edge */
}

/* Your existing panel styling works; this keeps it readable but not too heavy */
.title-panel{
  background: rgba(255,255,255,0.78);   /* lighter so image shows through */
  border-radius: 16px;
  padding: clamp(12px, 2.5vw, 20px) clamp(16px, 3vw, 28px);
  box-shadow: 0 10px 30px rgba(17,20,39,0.08);
  max-width: 1000px;
}

/* Optional: tweak on small screens */
@media (max-width: 600px){
  .heroindex{ min-height: 52vh; }
  .title-panel{ border-radius: 12px; }
}


/* Your existing .heroindex background system stays the same */

/* The translucent panel that fades at the edges */
.title-panel{
  /* base look */
  background: rgba(255,255,255,0.85);
  border-radius: 16px;
  padding: clamp(12px, 2.5vw, 20px) clamp(16px, 3vw, 28px);
  max-width: 1000px;

  /* radial fade with CSS mask (keeps text fully opaque) */
  -webkit-mask-image: radial-gradient(120% 140% at 50% 50%, #000 60%, transparent 100%);
          mask-image: radial-gradient(120% 140% at 50% 50%, #000 60%, transparent 100%);

  /* subtle lift */
  box-shadow: 0 10px 30px rgba(17,20,39,0.08);
}

/* Responsive, readable type */
.title-panel h1{
  margin: 0 0 6px;
  line-height: 1.12;
  font-weight: 800;
  font-size: clamp(20px, 3.4vw, 36px);
  /* soft “stroke” effect without SVG: */
  text-shadow: 0 0 6px rgba(255,255,255,0.95);
}
.title-panel .subtitle{
  margin: 6px 0 2px;
  font-weight: 700;
  font-size: clamp(14px, 2.2vw, 20px);
  text-shadow: 0 0 5px rgba(255,255,255,0.9);
}
.title-panel .date{
  margin: 0;
  font-weight: 700;
  font-size: clamp(14px, 2.2vw, 20px);
  text-shadow: 0 0 5px rgba(255,255,255,0.9);
}

/* Optional: tighten layout on very small screens */
@media (max-width: 420px){
  .title-panel{ border-radius: 12px; }
}

.nav{display:flex; align-items:center; justify-content:space-between; padding: 20px 0;}
.brand a{color: var(--text); text-decoration:none; font-weight:800; letter-spacing:0.3px;}
.brand small{color: var(--muted); display:block; font-weight:500; opacity:0.9;}

.nav a{color: var(--link); text-decoration:none; margin-left:16px; font-weight:600;}
.nav a:hover{text-decoration:underline;}
.nav .menu{display:flex; align-items:center; gap:10px;}
.nav-toggle{
  display:none; background: none; border: 1px solid rgba(0,0,0,0.12);
  color: var(--text); padding:8px 10px; border-radius:10px;
}

@media (max-width:760px){
  .nav .menu{display:none; color: #fff}
  .nav .menu.open{
    display:flex; flex-direction:column; align-items:flex-start;
    background: linear-gradient(180deg, var(--accent), #f3a6be); padding:10px 14px; border-radius:12px;
    box-shadow: 0 6px 18px rgba(232,134,168,0.35); position:absolute; right:10px; top:56px; color: #ffffff;
    border: none; text-decoration:none;
  }
  .nav .menu.open a:visited,
  .nav .menu.open a:hover,
  .nav .menu.open a:active {
    color: #fff;                 /* keep white on all states */
  }
  .nav-toggle{
    display:inline-flex;
    align-items:center;
    gap:8px;
    padding:10px 14px;
    border-radius:12px;
    border:none;
    background: linear-gradient(180deg, var(--accent), #f3a6be);
    color:#fff;                 /* white label */
    font-weight:800;
    box-shadow: 0 6px 18px rgba(232,134,168,0.35);
    cursor:pointer;
    font-size: clamp(16px, 4vw, 16px);  
  }
  .nav-toggle:hover{ filter: brightness(1.05); transform: translateY(-0.5px); }
  .nav-toggle:focus{ outline: 2px solid rgba(255,255,255,0.8); outline-offset: 2px; }

  /* When menu is open, you can flip the look (optional) */
  .nav-toggle.is-open{
    background:#fff;
    color: var(--accent);
    border:1px solid rgba(232,134,168,0.35);
    box-shadow: 0 4px 14px rgba(232,134,168,0.25);
  }
}

.hero{
  padding: 54px 0 22px;
  background:
    radial-gradient(900px 380px at 85% -40%, rgba(232,134,168,0.22), transparent 65%),
    radial-gradient(700px 420px at -20% -10%, rgba(255,216,229,0.45), transparent 60%);
  border-bottom: 1px solid rgba(0,0,0,0.06);
}

/* ---- Hero Background Image (Optional) -----------------------------------
   To use a custom hero image on any page, set:
     <div class="hero" style="--hero-image: url('images/your-hero.jpg')">
   By default, it falls back to the gradient background.
---------------------------------------------------------------------------*/
.hero{ position: relative; overflow: hidden; }
.hero > .container{ position: relative; z-index: 2; }

.hero::before{
  content:""; position:absolute; inset:0;
  background-image: var(--hero-image, none);
  background-size: cover; background-position: center;
  filter: saturate(1.05) contrast(0.98);
  z-index: 0;
}

.hero::after{
  content:""; position:absolute; inset:0; z-index:1;
  /* Soft light overlay to keep text readable over bright images */
  background:
    radial-gradient(80% 60% at 20% -10%, rgba(255,255,255,0.85), transparent 60%),
    linear-gradient(180deg, rgba(255,255,255,0.75), rgba(255,255,255,0.35));
  pointer-events:none;
}

.hero h1{font-size: clamp(28px, 4vw, 40px); margin:0 0 10px; line-height:1.08;}
.hero p{color: var(--muted); max-width: 60ch;}

main{padding: 24px 0 48px;}
section.card{
  background: var(--card);
  border: 1px solid rgba(0,0,0,0.06);
  border-radius: var(--radius);
  padding: clamp(16px, 3vw, 28px);
  margin: 16px 0;
  box-shadow: 0 10px 30px var(--shadow);
}

.grid{display:grid; gap:16px; grid-template-columns: repeat(12, 1fr);}
.overview-grid .col-8,
.overview-grid .col-4-sticky{
  grid-column: 1 / -1;
}
.overview-grid .col-4-sticky{
  position: static;
  margin-top: 8px;
  padding: 20px 24px;
}
.col-8{grid-column: span 8;}
.col-4{grid-column: span 4;}
.col-4-sticky{grid-column: span 4;
  position: static;
  background: #f7f0f6;
  padding: 12px;
  border-radius: 8px;}
/* 中の箱は見た目だけ。stickyは外す */
.right-col {
  position: sticky;
  top: 96px;           /* 固定ヘッダーの高さ＋余白に合わせて調整 */
  align-self: start;   /* grid の行頭から開始（stretch防止） */
  height: fit-content; /* 余白の暴れ防止（対応ブラウザで有効） */
}
/* モバイルで sticky 無効化（任意） */
@media (max-width: 900px){
  .right-col { position: static; }
}
.col-6{grid-column: span 6;}
.col-12{grid-column: span 12;}
/* Right column sticks only within its section */
.stick-right { 
  position: sticky;
  top: 50px;          /* ここで上からの余白（ナビに被るなら増やす） */
  align-self: start;  /* Grid内のSafari対策 */
}
@media (max-width:900px){ .col-8,.col-4,.col-6{grid-column: span 12;} }

h2{margin: 0 0 10px;}
h3{margin: 20px 0 10px;}
p, li{line-height: 1.7;}
ul{padding-left: 18px;}

footer.site{
  border-top: 1px solid rgba(0,0,0,0.06); padding: 18px 0;
  color: var(--muted); text-align:center; background: rgba(255,255,255,0.6);
}

.btn{
  display:inline-block; padding: 10px 14px; border-radius: 12px;
  background: linear-gradient(180deg, var(--accent), #f3a6be);
  color: #ffffff; text-decoration:none; font-weight:800; border: none;
  box-shadow: 0 6px 18px rgba(232,134,168,0.35);
}
.btn:hover{filter: brightness(1.04); transform: translateY(-0.5px);}

.badge{
  display:inline-block; padding: 6px 10px; border-radius:999px;
  background: rgba(232,134,168,0.12); color: #9a5c74; font-weight:700; font-size: 12px;
  border: 1px solid rgba(232,134,168,0.28);
}

table{
  width:100%; border-collapse: collapse; overflow:hidden; border-radius: 12px;
  border:1px solid rgba(0,0,0,0.06); background: #fff;
}
th, td{padding: 10px 12px; border-bottom: 1px solid rgba(0,0,0,0.06); text-align: left;}
tr:hover td{background: rgba(232,134,168,0.05);}
thead th{background: linear-gradient(180deg, #ffe7ef, #ffd8e5); color:#7a4b61;}

.image-placeholder{
  aspect-ratio: 16/9;
  background:
    repeating-linear-gradient(45deg, rgba(232,134,168,0.08), rgba(232,134,168,0.08) 12px, rgba(255,216,229,0.12) 12px, rgba(255,216,229,0.12) 24px);
  border: 1px dashed rgba(194,91,134,0.45);
  border-radius: 12px; display:flex; align-items:center; justify-content:center; color: var(--muted);
}

.kv{display:grid; grid-template-columns: 80px 1fr; gap: 10px;}
@media (max-width:600px){.kv{grid-template-columns: 1fr;} .kv b{display:block; opacity:0.8;}}

/* 既存 */
/*.accordion-content {
  max-height: 0;
  overflow: hidden;             *//* ← 閉じている間だけ隠す *//*
  transition: max-height 0.5s ease, padding 0.5s ease;
  padding: 0;
}*/
/*.accordion-content.open {
  max-height: 5000px;
  padding: 16px 0;
  overflow: visible;           */ /* ← 展開時は visible にする（sticky 有効化） *//*
}*/
/* default: hidden */
.accordion-content { display: none; }

/* visible when toggled */
.accordion-content.open { display: block; }


/* 🎛️ ボタンの見た目を強化 */
.accordion-toggle {
  appearance: none;
  -webkit-appearance: none;
  border: 1px solid var(--accent);
  background: var(--accent-2);
  color: var(--text);
  padding: 6px 10px;
  margin-left: 12px;
  border-radius: 999px;
  font: 600 14px/1 system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: background .2s ease, transform .1s ease, box-shadow .2s ease;
}
.accordion-toggle:hover { background: var(--accent); color: #fff; }
.accordion-toggle:active { transform: translateY(1px) scale(0.99); }
.accordion-toggle:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* 開閉状態で色を切替（任意） */
.accordion-toggle[aria-expanded="true"] {
  background: var(--accent);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 6px 18px rgba(232,134,168,0.35);
}

/* 2カラムのグリッド（左2 / 右1） */
.accordion-grid {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.right-col {
  position: sticky;
  top: 96px;           /* 固定ヘッダーの高さ＋余白に合わせて調整 */
  align-self: start;   /* grid の行頭から開始（stretch防止） */
  height: fit-content; /* 余白の暴れ防止（対応ブラウザで有効） */
}

/* 中の箱は見た目だけ。stickyは外す */
.sticky-box {
  position: static;
  background: #f7f0f6;
  padding: 12px;
  border-radius: 8px;
}

/* モバイルで sticky 無効化（任意） */
@media (max-width: 900px){
  .right-col { position: static; }
}

/* 見出しとボタンの並びを気持ちよく */
h2 {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 10px;
}

img.img { width: 100%; height: auto; border-radius: 12px; display: block; }

/* ==== Text outline utilities ==== */
/* 黒文字＋白い縁（太さは --stroke で調整） */
.outline-white {
  --stroke: 2px;                  /* 2px, 3px などお好みで */
  --stroke-color: #fff;
  color: #111;                    /* 文字の塗り（黒） */

  /* WebKit系（Chrome/Edge/Safari） */
  -webkit-text-stroke: var(--stroke) var(--stroke-color);
  text-stroke: var(--stroke) var(--stroke-color); /* 将来用 */

  /* Firefox 等のフォールバック（多方向の text-shadow で擬似縁取り） */
  text-shadow:
    1px 0   0 var(--stroke-color),
   -1px 0   0 var(--stroke-color),
    0   1px 0 var(--stroke-color),
    0  -1px 0 var(--stroke-color),
    1px 1px  0 var(--stroke-color),
   -1px 1px  0 var(--stroke-color),
    1px -1px 0 var(--stroke-color),
   -1px -1px 0 var(--stroke-color);
}

/* 文字が小さい場合は軽めの縁取り（細い & 影少なめ） */
.outline-white--light {
  --stroke: 1px;
  --stroke-color: #fff;
  color: #111;
  -webkit-text-stroke: var(--stroke) var(--stroke-color);
  text-shadow:
    0 0 1px var(--stroke-color),
    0 0 2px var(--stroke-color);
}



/* ==========================================================================
   HWO GA 2026: index page refinements
   ========================================================================== */

/* Make the hero title panel more compact and let more of the HWO image show. */
.heroindex .title-panel {
  width: fit-content;
  max-width: min(760px, 92%);
  padding: clamp(10px, 1.8vw, 16px) clamp(16px, 2.4vw, 24px);
  background: rgba(255, 255, 255, 0.74);
  border-radius: 14px;
  box-shadow: 0 8px 24px rgba(17, 20, 39, 0.07);
  -webkit-mask-image: none;
          mask-image: none;
  backdrop-filter: blur(3px);
  -webkit-backdrop-filter: blur(3px);
}

.heroindex .title-panel h1 {
  font-size: clamp(20px, 3vw, 34px);
  margin-bottom: 4px;
}

.heroindex .title-panel .subtitle {
  margin: 4px 0 2px;
  font-size: clamp(14px, 1.8vw, 18px);
}

.heroindex .title-panel .date {
  font-size: clamp(14px, 1.8vw, 18px);
}

/* Keep the credit readable but visually subordinate. */
.heroindex .credit {
  right: 10px;
  bottom: 8px;
  padding: 3px 6px;
  border-radius: 4px;
  background: rgba(0, 0, 0, 0.32);
  font-size: 9px;
  line-height: 1.3;
}

/* Venue: information on the left, embedded Google Map on the right. */
.venue-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(320px, 1.35fr);
  gap: clamp(20px, 4vw, 36px);
  align-items: center;
}

.venue-info h3 {
  margin-top: 0;
}

.venue-map {
  min-width: 0;
}

.venue-map iframe {
  display: block;
  width: 100%;
  height: 320px;
  border: 0;
  border-radius: 12px;
  box-shadow: 0 8px 24px rgba(17, 20, 39, 0.08);
}

@media (max-width: 800px) {
  .heroindex .title-panel {
    max-width: 94%;
  }

  .venue-grid {
    grid-template-columns: 1fr;
  }

  .venue-map iframe {
    height: 280px;
  }
}


/* Program schedule */

.program-date {
  margin-top: 30px;
  margin-bottom: 12px;
  padding: 12px 16px;
  background: #edf3f8;
  border-left: 4px solid #356a91;
  border-radius: 4px;
  font-size: 1.1rem;
}

.program-table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 28px;
}

.program-table td {
  padding: 12px 16px;
  border-bottom: 1px solid #e2e6ea;
  vertical-align: top;
}

.program-table td:first-child {
  width: 160px;
  white-space: nowrap;
  font-weight: 600;
  color: #355b78;
}

.program-table tr:nth-child(even) {
  background: #f8fafc;
}

/* Presentation instructions shared by both fields */
.presentation-submission {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid #d9dde5;
}

.presentation-submission h3 {
  margin-top: 0;
}

@media (max-width: 600px) {
  .program-table td {
    padding: 10px 8px;
    font-size: 0.9rem;
  }

  .program-table td:first-child {
    width: 115px;
  }
}