/* ================================================================
   日本医療ガス学会 第30回大会 — メインスタイルシート
   ================================================================ */

/* ───────────────────────────────────────
   CSS カスタムプロパティ
─────────────────────────────────────── */
:root {
  --primary: #004B8D;       /* 深藍 (さっぽろの空) */
  --primary-dark: #00336B;
  --primary-light: #1A6BB5;
  --accent: #00A4C8;        /* 氷河ブルー */
  --accent2: #4CAF50;       /* 医療グリーン */
  --gold: #C8920A;
  --silver: #888;
  --platinum: #7B68EE;
  --snow: #F0F6FB;
  --white: #FFFFFF;
  --text: #1A2B3C;
  --text-muted: #5A6A7A;
  --border: #D6E4F0;
  --shadow: 0 4px 24px rgba(0,75,141,.10);
  --shadow-lg: 0 8px 40px rgba(0,75,141,.16);
  --radius: 12px;
  --radius-lg: 20px;
  --transition: all .3s cubic-bezier(.4,0,.2,1);
  --font-sans: 'Noto Sans JP', sans-serif;
  --font-serif: 'Noto Serif JP', serif;
  --nav-h: 68px;
}

/* ───────────────────────────────────────
   リセット・ベース
─────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-sans);
  color: var(--text);
  background: var(--white);
  line-height: 1.75;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, select, textarea { font-family: inherit; }

/* ───────────────────────────────────────
   ユーティリティ
─────────────────────────────────────── */
.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
}
.mt-2 { margin-top: 2rem; }
.section {
  padding: 80px 0;
}
.section-light { background: var(--snow); }
.section-white { background: var(--white); }

/* ───────────────────────────────────────
   セクション共通ヘッダー
─────────────────────────────────────── */
.section-header {
  text-align: center;
  margin-bottom: 48px;
}
.section-label {
  display: inline-block;
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .15em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 8px;
}
.section-title {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 12px;
}
.section-divider {
  width: 48px; height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  margin: 0 auto 16px;
  border-radius: 2px;
}
.section-note {
  color: var(--text-muted);
  font-size: .9rem;
}

/* ───────────────────────────────────────
   ボタン
─────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 50px;
  font-size: .95rem;
  font-weight: 700;
  transition: var(--transition);
  white-space: nowrap;
}
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: var(--white);
  box-shadow: 0 4px 16px rgba(0,75,141,.3);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,75,141,.4);
}
.btn-outline {
  border: 2px solid var(--white);
  color: var(--white);
  background: transparent;
}
.btn-outline:hover {
  background: rgba(255,255,255,.15);
  transform: translateY(-2px);
}
.btn-sm { padding: 8px 18px; font-size: .85rem; }
.btn-lg { padding: 14px 36px; font-size: 1rem; }

/* ───────────────────────────────────────
   ナビゲーション
─────────────────────────────────────── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-h);
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}
.navbar.scrolled {
  box-shadow: 0 2px 20px rgba(0,75,141,.12);
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.nav-logo { font-size: 1.6rem; }
.nav-title-wrap { display: flex; flex-direction: column; }
.nav-main-title {
  font-family: var(--font-serif);
  font-size: .8rem;
  font-weight: 700;
  color: var(--primary);
  line-height: 1.2;
}
.nav-sub-title {
  font-size: .7rem;
  color: var(--accent);
  font-weight: 700;
}
.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav-link {
  padding: 6px 10px;
  border-radius: 6px;
  font-size: .8rem;
  font-weight: 500;
  color: var(--text);
  transition: var(--transition);
  white-space: nowrap;
}
.nav-link:hover, .nav-link.active {
  color: var(--primary);
  background: var(--snow);
}
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 6px;
}
.nav-toggle span {
  display: block;
  width: 24px; height: 2px;
  background: var(--primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* ───────────────────────────────────────
   ヒーローセクション
─────────────────────────────────────── */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding-top: var(--nav-h);
}
.hero-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(145deg,
    #002A55 0%,
    #004B8D 40%,
    #006B9D 70%,
    #00A4C8 100%);
  z-index: 0;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 50%, rgba(255,255,255,.05) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(0,164,200,.15) 0%, transparent 40%);
}
/* パーティクル */
.hero-particles {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
}
.particle {
  position: absolute;
  width: 4px; height: 4px;
  border-radius: 50%;
  background: rgba(255,255,255,.4);
  animation: floatUp linear infinite;
}
@keyframes floatUp {
  0%   { transform: translateY(100vh) scale(0); opacity: 0; }
  10%  { opacity: 1; }
  90%  { opacity: 1; }
  100% { transform: translateY(-10vh) scale(1.5); opacity: 0; }
}
.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 40px 24px;
  max-width: 900px;
  width: 100%;
}
.hero-badge {
  display: inline-block;
  background: rgba(255,255,255,.15);
  border: 1px solid rgba(255,255,255,.4);
  color: #fff;
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .12em;
  padding: 6px 20px;
  border-radius: 50px;
  margin-bottom: 20px;
  backdrop-filter: blur(4px);
}
.hero-title {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  margin-bottom: 28px;
}
.hero-title-jp {
  font-family: var(--font-serif);
  font-size: clamp(1.4rem, 4vw, 2rem);
  color: rgba(255,255,255,.85);
  font-weight: 400;
  letter-spacing: .06em;
}
.hero-title-num {
  font-family: var(--font-serif);
  font-size: clamp(2.2rem, 6vw, 3.6rem);
  color: #fff;
  font-weight: 700;
  letter-spacing: .04em;
  line-height: 1.1;
}
.hero-theme {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 32px;
}
.theme-label {
  display: inline-block;
  font-size: .75rem;
  color: var(--accent);
  font-weight: 700;
  letter-spacing: .1em;
}
.theme-text {
  font-family: var(--font-serif);
  font-size: clamp(1rem, 2.5vw, 1.3rem);
  color: rgba(255,255,255,.95);
  font-weight: 600;
}
.hero-meta {
  display: flex;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
  margin-bottom: 36px;
}
.hero-meta-item {
  display: flex;
  align-items: center;
  gap: 12px;
  background: rgba(255,255,255,.12);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,.25);
  border-radius: var(--radius);
  padding: 12px 20px;
  text-align: left;
}
.hero-meta-item i {
  font-size: 1.4rem;
  color: var(--accent);
}
.hero-meta-item div {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.meta-label {
  font-size: .7rem;
  color: rgba(255,255,255,.65);
  font-weight: 600;
  letter-spacing: .08em;
}
.meta-value {
  font-size: .95rem;
  color: #fff;
  font-weight: 700;
}
.hero-cta {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}
/* カウントダウン */
.hero-countdown { text-align: center; }
.countdown-title {
  font-size: .8rem;
  color: rgba(255,255,255,.7);
  font-weight: 600;
  letter-spacing: .1em;
  margin-bottom: 10px;
}
.countdown-boxes {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}
.countdown-box {
  background: rgba(255,255,255,.15);
  border: 1px solid rgba(255,255,255,.3);
  border-radius: var(--radius);
  padding: 12px 18px;
  min-width: 72px;
  text-align: center;
  backdrop-filter: blur(4px);
}
.countdown-box span {
  display: block;
  font-size: 1.8rem;
  font-weight: 900;
  color: #fff;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}
.countdown-box small {
  font-size: .65rem;
  color: rgba(255,255,255,.7);
  letter-spacing: .06em;
}
.countdown-sep {
  font-size: 1.8rem;
  font-weight: 900;
  color: rgba(255,255,255,.5);
}
.hero-scroll-hint {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: rgba(255,255,255,.6);
  font-size: .7rem;
  letter-spacing: .1em;
  animation: bounce 2s ease-in-out infinite;
}
@keyframes bounce {
  0%,100% { transform: translateX(-50%) translateY(0); }
  50%      { transform: translateX(-50%) translateY(8px); }
}

/* ───────────────────────────────────────
   アニメーション
─────────────────────────────────────── */
.animate-fade-up {
  opacity: 0;
  transform: translateY(24px);
  animation: fadeUp .8s ease forwards;
}
.delay-1 { animation-delay: .1s; }
.delay-2 { animation-delay: .25s; }
.delay-3 { animation-delay: .4s; }
.delay-4 { animation-delay: .55s; }
.delay-5 { animation-delay: .7s; }
@keyframes fadeUp {
  to { opacity: 1; transform: translateY(0); }
}
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity .7s ease, transform .7s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ───────────────────────────────────────
   ニューステロップ
─────────────────────────────────────── */
.news-ticker {
  background: var(--primary);
  color: #fff;
  display: flex;
  align-items: stretch;
  height: 44px;
  overflow: hidden;
}
.ticker-label {
  background: var(--accent);
  padding: 0 20px;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .05em;
  flex-shrink: 0;
  white-space: nowrap;
}
.ticker-wrap {
  flex: 1;
  overflow: hidden;
  display: flex;
  align-items: center;
}
.ticker-list {
  display: flex;
  gap: 80px;
  white-space: nowrap;
  animation: ticker 30s linear infinite;
}
.ticker-list li {
  font-size: .82rem;
  opacity: .92;
}
@keyframes ticker {
  0%   { transform: translateX(100vw); }
  100% { transform: translateX(-100%); }
}

/* ───────────────────────────────────────
   ご挨拶
─────────────────────────────────────── */
.greeting-card {
  display: flex;
  gap: 48px;
  align-items: flex-start;
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: 48px;
}
.greeting-photo-wrap {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  text-align: center;
}
.greeting-photo-placeholder {
  position: relative;
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  padding: 5px;
  box-shadow:
    0 0 0 4px var(--white),
    0 0 0 8px var(--primary),
    0 8px 32px rgba(0,75,141,.28);
  overflow: visible;
  display: flex;
  align-items: center;
  justify-content: center;
}
.greeting-photo-placeholder::before {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: 50%;
  background: conic-gradient(
    var(--primary) 0deg,
    var(--accent) 120deg,
    #7dd3f0 200deg,
    var(--primary) 360deg
  );
  z-index: -1;
  animation: rotate-ring 8s linear infinite;
}
@keyframes rotate-ring {
  to { transform: rotate(360deg); }
}
.greeting-photo-inner {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  overflow: hidden;
  background: var(--snow);
}
.greeting-photo-placeholder img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 15%;
  display: block;
  border-radius: 50%;
}
.greeting-role {
  font-size: .75rem;
  color: var(--text-muted);
  font-weight: 600;
  letter-spacing: .06em;
}
.greeting-name {
  font-family: var(--font-serif);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary);
}
.greeting-affil {
  font-size: .8rem;
  color: var(--text-muted);
  line-height: 1.5;
}
.greeting-text p {
  margin-bottom: 16px;
  line-height: 1.9;
  color: var(--text);
}
.greeting-text p:last-child { margin-bottom: 0; }
.greeting-closing {
  font-family: var(--font-serif);
  font-weight: 600;
  color: var(--primary) !important;
  font-size: 1.05rem;
}

/* ───────────────────────────────────────
   大会概要
─────────────────────────────────────── */
.info-grid {
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: 32px;
  align-items: start;
}
.info-table-wrap {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.info-table {
  width: 100%;
  border-collapse: collapse;
}
.info-table tr:not(:last-child) {
  border-bottom: 1px solid var(--border);
}
.info-table th {
  padding: 16px 20px;
  background: var(--snow);
  font-size: .85rem;
  font-weight: 700;
  color: var(--primary);
  white-space: nowrap;
  width: 200px;
  vertical-align: middle;
}
.info-table th i { margin-right: 8px; color: var(--accent); }
.info-table td {
  padding: 16px 20px;
  font-size: .9rem;
  vertical-align: middle;
}
.info-table td small {
  display: block;
  color: var(--text-muted);
  font-size: .8rem;
  margin-top: 4px;
}
.fee-item {
  display: inline-block;
  background: var(--snow);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px 10px;
  font-size: .8rem;
  font-weight: 700;
  margin: 2px;
  color: var(--primary);
}

/* タイムライン */
.info-schedule-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: 28px;
}
.schedule-card-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border);
}
.schedule-card-title i { margin-right: 8px; color: var(--accent); }
.schedule-timeline {
  display: flex;
  flex-direction: column;
  gap: 0;
}
.timeline-item {
  display: flex;
  gap: 14px;
  position: relative;
  padding-bottom: 20px;
}
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item:not(:last-child)::before {
  content: '';
  position: absolute;
  left: 7px; top: 16px;
  width: 2px;
  height: calc(100% - 16px);
  background: var(--border);
}
.timeline-dot {
  width: 16px; height: 16px;
  border-radius: 50%;
  background: var(--border);
  border: 2px solid var(--white);
  flex-shrink: 0;
  margin-top: 2px;
  z-index: 1;
}
.timeline-item.done .timeline-dot { background: var(--accent2); }
.timeline-item.active .timeline-dot {
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(200,146,10,.2);
  animation: pulse 2s infinite;
}
.timeline-item.highlight .timeline-dot { background: var(--primary); }
@keyframes pulse {
  0%,100% { box-shadow: 0 0 0 4px rgba(200,146,10,.2); }
  50%      { box-shadow: 0 0 0 8px rgba(200,146,10,.1); }
}
.timeline-content {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.timeline-date {
  font-size: .75rem;
  font-weight: 700;
  color: var(--text-muted);
}
.timeline-event {
  font-size: .88rem;
  font-weight: 600;
  color: var(--text);
}
.timeline-item.active .timeline-event { color: var(--gold); }
.timeline-item.highlight .timeline-event { color: var(--primary); font-weight: 700; }

/* ───────────────────────────────────────
   プログラム タブ
─────────────────────────────────────── */
.tab-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 24px;
  border-bottom: 2px solid var(--border);
  padding-bottom: 0;
}
.tab-btn {
  padding: 10px 24px;
  border-radius: var(--radius) var(--radius) 0 0;
  font-size: .9rem;
  font-weight: 700;
  color: var(--text-muted);
  background: transparent;
  border: 2px solid transparent;
  border-bottom: none;
  transition: var(--transition);
  position: relative;
  bottom: -2px;
}
.tab-btn:hover { color: var(--primary); background: var(--snow); }
.tab-btn.active {
  color: var(--primary);
  background: var(--white);
  border-color: var(--border);
  border-bottom-color: var(--white);
}
.tab-content { display: none; }
.tab-content.active { display: block; }

/* プログラム表 */
.program-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  background: var(--white);
}
.program-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 700px;
}
.program-table thead th {
  background: var(--primary);
  color: #fff;
  padding: 14px 16px;
  font-size: .85rem;
  font-weight: 700;
  text-align: center;
}
.col-time { width: 140px; }
.col-room { width: calc((100% - 140px) / 3); }
.program-table tbody td {
  border: 1px solid var(--border);
  padding: 12px 16px;
  font-size: .85rem;
  vertical-align: middle;
  text-align: center;
}
.time-cell {
  background: var(--snow);
  font-weight: 700;
  color: var(--primary);
  font-size: .82rem;
  white-space: nowrap;
}
.special-row {
  background: #EFF7FF !important;
  font-weight: 600;
  color: var(--primary);
  text-align: center !important;
}
.special-row i { margin-right: 6px; color: var(--accent); }
.special-row.keynote { background: #FFF8E8 !important; color: #7A4800; }
.special-row.lunch   { background: #F0FFF4 !important; color: #2D6A4F; }
.special-row.party   { background: #FEF3F2 !important; color: #7A1A1A; }
.special-row.awards  { background: #FFFDE8 !important; color: #7A4800; }
.special-row.opening { background: #EEF2FF !important; color: #3A3A9A; }
.special-row.closing { background: #EEF2FF !important; color: #3A3A9A; }
.session-cell { font-size: .82rem; line-height: 1.5; }
.session-cell small { display: block; color: var(--text-muted); margin-top: 4px; }
.session-a { background: #F0FAFF !important; }
.session-b { background: #F5FFF5 !important; }
.session-c { background: #FFFBF0 !important; }

/* セッション一覧 */
.sessions-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.session-card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 20px;
  text-align: center;
  transition: var(--transition);
}
.session-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.session-icon {
  width: 60px; height: 60px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 1.4rem;
}
.keynote-icon { background: #FFF8E8; color: var(--gold); }
.invited-icon { background: #EFF7FF; color: var(--primary); }
.symp-icon    { background: #F0FFF4; color: var(--accent2); }
.edu-icon     { background: #F5F0FF; color: #7B5EA7; }
.general-icon { background: #EFF7FF; color: var(--accent); }
.ws-icon      { background: #FFF0F0; color: #C0392B; }
.session-card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
}
.session-card p {
  font-size: .82rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}
.session-count {
  display: inline-block;
  background: var(--snow);
  border: 1px solid var(--border);
  border-radius: 50px;
  padding: 4px 12px;
  font-size: .75rem;
  font-weight: 700;
  color: var(--primary);
}

/* ───────────────────────────────────────
   演題登録
─────────────────────────────────────── */
.abstract-deadline-banner {
  background: linear-gradient(135deg, #FFF3CD, #FFE58F);
  border: 1px solid #F0AD00;
  border-radius: var(--radius);
  padding: 16px 24px;
  font-size: .95rem;
  font-weight: 600;
  color: #7A4800;
  text-align: center;
  margin-bottom: 36px;
}
.abstract-deadline-banner i { margin-right: 8px; }
.abstract-layout {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 36px;
  align-items: start;
}
.abstract-guide h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 16px;
}
.abstract-guide h3 i { margin-right: 8px; color: var(--accent); }
.category-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 28px;
}
.category-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: .87rem;
  color: var(--text);
}
.cat-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px; height: 24px;
  border-radius: 6px;
  font-size: .7rem;
  font-weight: 900;
  color: #fff;
  flex-shrink: 0;
}
.cat-a { background: #004B8D; }
.cat-b { background: #00A4C8; }
.cat-c { background: #4CAF50; }
.cat-d { background: #9C27B0; }
.cat-e { background: #FF5722; }
.cat-f { background: #795548; }
.cat-g { background: #F44336; }
.cat-h { background: #607D8B; }
.notes-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.notes-list li {
  font-size: .82rem;
  color: var(--text-muted);
  padding-left: 14px;
  position: relative;
  line-height: 1.6;
}
.notes-list li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

/* ───────────────────────────────────────
   フォーム共通
─────────────────────────────────────── */
.form {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: 36px;
}
.abstract-form-wrap h3,
.reg-form-wrap h3,
.contact-form-wrap h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border);
}
.abstract-form-wrap h3 i,
.reg-form-wrap h3 i,
.contact-form-wrap h3 i { margin-right: 8px; color: var(--accent); }

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 16px;
}
.form-group label {
  font-size: .85rem;
  font-weight: 700;
  color: var(--text);
}
.form-group input,
.form-group select,
.form-group textarea {
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: .9rem;
  color: var(--text);
  background: var(--white);
  transition: var(--transition);
  outline: none;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(0,164,200,.12);
}
.form-group input.error,
.form-group select.error,
.form-group textarea.error {
  border-color: #F44336;
}
.form-group textarea { resize: vertical; min-height: 120px; }
.form-group input[type="checkbox"] {
  width: 18px; height: 18px;
  margin-right: 8px;
  accent-color: var(--primary);
  display: inline;
  vertical-align: middle;
  padding: 0;
}
.req {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  font-size: .65rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  margin-left: 4px;
}
.opt {
  display: inline-block;
  background: var(--text-muted);
  color: #fff;
  font-size: .65rem;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 4px;
  margin-left: 4px;
}
.char-count {
  font-size: .78rem;
  color: var(--text-muted);
  text-align: right;
  margin-top: 4px;
}
.form-actions {
  margin-top: 8px;
  display: flex;
  justify-content: center;
}

/* ───────────────────────────────────────
   参加登録 — 料金カード
─────────────────────────────────────── */
.fee-cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 48px;
}
.fee-card {
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 28px 20px;
  text-align: center;
  border: 2px solid transparent;
  transition: var(--transition);
}
.fee-card:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.fee-card-highlight {
  border-color: var(--accent);
  background: linear-gradient(135deg, var(--snow), #EBF6FF);
}
.fee-icon {
  width: 56px; height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 14px;
  font-size: 1.3rem;
}
.fee-card h3 {
  font-size: .95rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
}
.fee-price {
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--primary);
  margin-bottom: 8px;
}
.fee-card p {
  font-size: .8rem;
  color: var(--text-muted);
}
.reg-form-wrap { max-width: 800px; margin: 0 auto; }

/* ───────────────────────────────────────
   会場案内
─────────────────────────────────────── */
.venue-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 36px;
  align-items: start;
}
.venue-main-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: 32px;
  margin-bottom: 24px;
}
.venue-main-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
}
.venue-main-card h3 i { margin-right: 8px; color: var(--accent); }
.venue-address {
  color: var(--text-muted);
  font-size: .88rem;
  margin-bottom: 20px;
}
.venue-access {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}
.venue-access li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: .88rem;
}
.venue-access li i {
  color: var(--accent);
  width: 18px;
  flex-shrink: 0;
  margin-top: 3px;
}
.venue-hotels {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: 32px;
}
.venue-hotels h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 16px;
}
.venue-hotels h3 i { margin-right: 8px; color: var(--accent); }
.hotel-list { display: flex; flex-direction: column; gap: 10px; margin-bottom: 12px; }
.hotel-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 10px 14px;
  background: var(--snow);
  border-radius: 8px;
}
.hotel-item strong { font-size: .9rem; color: var(--primary); }
.hotel-item span { font-size: .78rem; color: var(--text-muted); }
.hotel-note { font-size: .78rem; color: var(--text-muted); }
.venue-map-wrap iframe { width: 100%; border-radius: var(--radius); }
.sapporo-charm {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-top: 16px;
  color: #fff;
}
.sapporo-charm h4 {
  font-size: .95rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.sapporo-charm h4 i { margin-right: 8px; }
.charm-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}
.charm-item {
  background: rgba(255,255,255,.15);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: .82rem;
  font-weight: 500;
}

/* ───────────────────────────────────────
   スポンサー
─────────────────────────────────────── */
.sponsor-intro {
  text-align: center;
  max-width: 600px;
  margin: 0 auto 40px;
  color: var(--text-muted);
  font-size: .9rem;
  line-height: 1.8;
}
.sponsor-tiers {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-bottom: 36px;
}
.sponsor-tier { padding: 24px; border-radius: var(--radius); }
.sponsor-tier.platinum { background: linear-gradient(135deg, #F0EEFF, #E8E0FF); border: 2px solid #C4B5FD; }
.sponsor-tier.gold     { background: linear-gradient(135deg, #FFFDE8, #FFF3C0); border: 2px solid #F0CA50; }
.sponsor-tier.silver   { background: linear-gradient(135deg, #F8F8F8, #EEEEEE); border: 2px solid #CCCCCC; }
.tier-badge {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 50px;
  font-size: .8rem;
  font-weight: 700;
  margin-bottom: 16px;
}
.platinum .tier-badge { background: #7B68EE; color: #fff; }
.gold     .tier-badge { background: var(--gold); color: #fff; }
.silver   .tier-badge { background: var(--silver); color: #fff; }
.tier-slots {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}
.slot-placeholder {
  flex: 1;
  min-width: 160px;
  height: 80px;
  border-radius: var(--radius);
  border: 2px dashed rgba(0,0,0,.2);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: .85rem;
  color: rgba(0,0,0,.4);
  font-weight: 600;
}
.sponsor-cta { text-align: center; }

/* ───────────────────────────────────────
   お問い合わせ
─────────────────────────────────────── */
.contact-layout {
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 36px;
  align-items: start;
}
.contact-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: 32px;
}
.contact-card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 16px;
}
.contact-card h3 i { margin-right: 8px; color: var(--accent); }
.contact-card p { font-size: .88rem; color: var(--text-muted); margin-bottom: 4px; }
.contact-list {
  margin-top: 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.contact-list li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: .86rem;
  color: var(--text);
}
.contact-list li i { color: var(--accent); width: 18px; flex-shrink: 0; margin-top: 3px; }
.contact-form-wrap { background: var(--white); border-radius: var(--radius-lg); box-shadow: var(--shadow); padding: 36px; }

/* 事務局のみ表示（フォームなし） */
.contact-solo {
  display: flex;
  justify-content: center;
}
.contact-card-center {
  max-width: 560px;
  width: 100%;
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: 40px;
}
.contact-note {
  margin-top: 20px;
  padding: 12px 16px;
  background: #f0f7ff;
  border-left: 3px solid var(--accent);
  border-radius: 6px;
  font-size: .84rem;
  color: var(--text-muted);
}
.contact-note i { color: var(--accent); margin-right: 6px; }

/* ===== Under Construction ===== */
.under-construction-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 64px 32px;
  background: linear-gradient(135deg, #f0f7ff 0%, #e8f4ff 100%);
  border-radius: var(--radius-lg);
  border: 2px dashed rgba(0,120,215,.25);
  text-align: center;
  gap: 12px;
}
.uc-icon {
  font-size: 3.5rem;
  line-height: 1;
  filter: drop-shadow(0 2px 8px rgba(0,0,0,.12));
}
.uc-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: .08em;
  margin: 0;
}
.uc-text {
  font-size: .92rem;
  color: var(--text-muted);
  line-height: 1.75;
  margin: 0;
}

/* ───────────────────────────────────────
   フッター
─────────────────────────────────────── */
.footer { background: var(--primary-dark); color: rgba(255,255,255,.8); }
.footer-top { padding: 56px 0 40px; }
.footer-grid {
  display: grid;
  grid-template-columns: 240px 1fr 1fr 1fr;
  gap: 40px;
}
.footer-brand { display: flex; flex-direction: column; gap: 8px; }
.footer-logo { font-size: 2.4rem; }
.footer-title {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 700;
  color: #fff;
  line-height: 1.5;
}
.footer-tagline { font-size: .8rem; color: rgba(255,255,255,.55); line-height: 1.7; }
.footer-col h4 {
  font-size: .85rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 14px;
  letter-spacing: .05em;
}
.footer-col ul { display: flex; flex-direction: column; gap: 8px; }
.footer-col ul li a {
  font-size: .82rem;
  color: rgba(255,255,255,.65);
  transition: var(--transition);
}
.footer-col ul li a:hover { color: var(--accent); }
.footer-dates {
  margin-top: 16px;
  font-size: .78rem;
  color: rgba(255,255,255,.55);
  line-height: 1.8;
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1);
  padding: 20px 0;
  text-align: center;
}
.footer-bottom p { font-size: .78rem; color: rgba(255,255,255,.45); line-height: 1.8; }

/* ───────────────────────────────────────
   Toast 通知
─────────────────────────────────────── */
.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--primary-dark);
  color: #fff;
  padding: 12px 28px;
  border-radius: 50px;
  font-size: .9rem;
  font-weight: 600;
  box-shadow: 0 8px 32px rgba(0,0,0,.25);
  opacity: 0;
  pointer-events: none;
  transition: opacity .3s, transform .3s;
  z-index: 2000;
  white-space: nowrap;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.toast.success { background: #2D6A4F; }
.toast.error   { background: #7A1A1A; }

/* ───────────────────────────────────────
   Back to Top
─────────────────────────────────────── */
.back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 999;
  width: 48px; height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  font-size: 1.1rem;
  box-shadow: 0 4px 16px rgba(0,75,141,.35);
  transition: var(--transition);
  opacity: 0;
  pointer-events: none;
  display: flex;
  align-items: center;
  justify-content: center;
}
.back-to-top.show {
  opacity: 1;
  pointer-events: auto;
}
.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(0,75,141,.45);
}

/* ───────────────────────────────────────
   レスポンシブ
─────────────────────────────────────── */
@media (max-width: 1024px) {
  .info-grid            { grid-template-columns: 1fr; }
  .abstract-layout      { grid-template-columns: 1fr; }
  .contact-layout       { grid-template-columns: 1fr; }
  .footer-grid          { grid-template-columns: 1fr 1fr; gap: 32px; }
  .sessions-grid        { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root { --nav-h: 60px; }
  .section { padding: 56px 0; }

  /* ナビ */
  .nav-menu {
    position: fixed;
    top: var(--nav-h); left: 0; right: 0;
    background: rgba(255,255,255,.97);
    backdrop-filter: blur(12px);
    flex-direction: column;
    gap: 0;
    padding: 12px 0 20px;
    border-bottom: 1px solid var(--border);
    transform: translateY(-120%);
    transition: var(--transition);
    z-index: 999;
  }
  .nav-menu.open { transform: translateY(0); }
  .nav-link { padding: 12px 24px; border-radius: 0; font-size: .9rem; }
  .nav-toggle { display: flex; }

  /* ヒーロー */
  .hero-meta { gap: 16px; }
  .hero-meta-item { padding: 10px 14px; }
  .meta-value { font-size: .85rem; }
  .countdown-box { min-width: 58px; padding: 10px 12px; }
  .countdown-box span { font-size: 1.4rem; }

  /* 挨拶 */
  .greeting-card {
    flex-direction: column;
    padding: 28px 24px;
    gap: 24px;
  }
  .greeting-photo-wrap { width: 100%; flex-direction: row; gap: 20px; }
  .greeting-photo-placeholder { width: 120px; height: 120px; }

  /* テーブル */
  .info-table th { width: 130px; font-size: .8rem; }

  /* 参加費 */
  .fee-cards { grid-template-columns: 1fr 1fr; }

  /* 会場 */
  .venue-layout { grid-template-columns: 1fr; }

  /* セッション */
  .sessions-grid { grid-template-columns: 1fr 1fr; }

  /* フォーム */
  .form-row { grid-template-columns: 1fr; }
  .form { padding: 24px; }

  /* フッター */
  .footer-grid { grid-template-columns: 1fr; gap: 24px; }
  .footer-brand { flex-direction: row; align-items: center; }
}

@media (max-width: 480px) {
  .hero-cta { flex-direction: column; align-items: center; }
  .fee-cards { grid-template-columns: 1fr 1fr; }
  .sessions-grid { grid-template-columns: 1fr; }
  .charm-grid { grid-template-columns: 1fr; }
  .tab-btn { padding: 8px 14px; font-size: .8rem; }
  .countdown-boxes { gap: 4px; }
  .countdown-sep { font-size: 1.2rem; }
}