/* ===== リセット・変数 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --orange:    #ff6600;
  --orange-lt: #fff3eb;
  --blue:      #1a6fc4;
  --blue-lt:   #e8f2fc;
  --dark:      #1a1a1a;
  --gray:      #f5f5f5;
  --border:    #e5e5e5;
  --text:      #333333;
  --muted:     #777777;
  --white:     #ffffff;
  --shadow:    0 2px 12px rgba(0,0,0,0.08);
  --radius:    10px;
}

html { scroll-behavior: smooth; }

body {
  background: var(--white);
  color: var(--text);
  font-family: 'Noto Sans JP', 'Hiragino Kaku Gothic ProN', 'Meiryo', sans-serif;
  font-size: 15px;
  line-height: 1.7;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }

/* ===== アイコンサイズ ===== */
.icon-xs { width: 24px;  height: 24px;  object-fit: contain; flex-shrink: 0; }
.icon-sm { width: 40px;  height: 40px;  object-fit: contain; flex-shrink: 0; }
.icon-md { width: 64px;  height: 64px;  object-fit: contain; flex-shrink: 0; }
.cat-icon { width: 80px; height: 80px;  object-fit: contain; margin: 0 auto 0.7rem; display: block; }
.step-icon { display: block; margin-bottom: 0.6rem; }

/* ===== ニコニコ風トップバー ===== */
.nico-topbar { background: #252525; color: #ccc; font-size: 0.75rem; }
.nico-topbar-inner {
  max-width: 1100px; margin: 0 auto; padding: 0 1rem;
  display: flex; align-items: center; gap: 1rem; height: 36px;
}
.nico-logo { color: #fff; font-weight: 700; font-size: 0.85rem; white-space: nowrap; flex-shrink: 0; }
.nico-nav  { display: flex; gap: 0.8rem; flex: 1; overflow: hidden; }
.nico-nav span { cursor: pointer; white-space: nowrap; transition: color 0.15s; }
.nico-nav span:hover { color: #fff; }
.nico-auth { display: flex; gap: 0.5rem; flex-shrink: 0; align-items: center; }
.auth-link { font-size: 0.75rem; color: #ccc; cursor: pointer; }
.auth-link:hover { color: #fff; }
.auth-btn {
  background: var(--orange); color: #fff; font-size: 0.72rem; font-weight: 700;
  padding: 3px 10px; border-radius: 3px; white-space: nowrap; cursor: pointer;
  transition: opacity 0.15s;
}
.auth-btn:hover { opacity: 0.85; }

/* ===== イベントヘッダー ===== */
.event-header {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 100;
  box-shadow: 0 1px 6px rgba(0,0,0,0.06);
}
.event-header-inner {
  max-width: 1100px; margin: 0 auto; padding: 0 1rem;
  display: flex; align-items: center; gap: 1.5rem; height: 64px;
}
.event-logo { flex-shrink: 0; display: flex; align-items: center; }
.event-logo img { height: 52px; width: auto; object-fit: contain; }

.event-nav { display: flex; gap: 0.2rem; flex: 1; }
.enav-item {
  font-size: 0.82rem; padding: 0.3rem 0.7rem; border-radius: 4px;
  color: var(--muted); cursor: pointer; white-space: nowrap;
  transition: color 0.15s, background 0.15s;
}
.enav-item:hover { color: var(--orange); }
.enav-item.active { color: var(--orange); font-weight: 700; border-bottom: 2px solid var(--orange); border-radius: 0; }

.notify-btn {
  display: flex; align-items: center; gap: 0.4rem;
  padding: 0.4rem 1rem; border: 1px solid var(--border); border-radius: 99px;
  font-size: 0.78rem; color: var(--text); cursor: pointer; white-space: nowrap; flex-shrink: 0;
  transition: border-color 0.15s, color 0.15s;
}
.notify-btn:hover { border-color: var(--orange); color: var(--orange); }

/* ===== セクション共通 ===== */
.section-inner { max-width: 1000px; margin: 0 auto; padding: 4rem 1.5rem; }

.section-title {
  display: flex; align-items: center; gap: 0.7rem;
  font-size: 1.2rem; font-weight: 700; margin-bottom: 2rem; color: var(--dark);
}

/* ===== ヒーロー ===== */
.hero { background: var(--white); overflow: hidden; }
.hero-inner {
  max-width: 1100px; margin: 0 auto; padding: 3rem 1.5rem 3.5rem;
  display: grid; grid-template-columns: 1fr 440px; gap: 2rem; align-items: center;
}
.hero-text { display: flex; flex-direction: column; gap: 1.2rem; }

.unofficial-badge {
  display: inline-block; border: 2px solid var(--orange); color: var(--orange);
  font-size: 0.78rem; font-weight: 700; padding: 3px 12px; border-radius: 99px; width: fit-content;
}

.hero-title { display: flex; flex-direction: column; line-height: 1.05; }
.title-line1 { font-size: clamp(1.5rem, 3.5vw, 2.2rem); font-weight: 900; color: var(--dark); }
.title-line2 { font-size: clamp(3.5rem, 9vw, 6rem); font-weight: 900; color: var(--dark); letter-spacing: -0.02em; }
.orange { color: var(--orange); }
.hero-sub { font-size: 1.05rem; font-weight: 700; color: var(--blue); }

.hero-btns { display: flex; gap: 0.8rem; flex-wrap: wrap; }

.btn-primary {
  display: inline-flex; align-items: center; gap: 0.3rem;
  background: var(--orange); color: #fff; font-weight: 700; font-size: 0.95rem;
  padding: 0.75rem 1.8rem; border-radius: 6px; cursor: pointer;
  transition: opacity 0.15s, transform 0.15s;
}
.btn-primary:hover { opacity: 0.88; transform: translateY(-1px); }

.btn-secondary {
  display: inline-flex; align-items: center; gap: 0.4rem;
  background: transparent; color: var(--text); font-weight: 700; font-size: 0.95rem;
  padding: 0.75rem 1.5rem; border-radius: 6px; border: 2px solid var(--border); cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
.btn-secondary:hover { border-color: var(--orange); color: var(--orange); }

.hero-visual { display: flex; align-items: center; justify-content: center; }
.hero-img {
  width: 100%; max-width: 440px; border-radius: 14px;
  box-shadow: 0 4px 24px rgba(255,102,0,0.1);
}

/* ===== 開催概要 ===== */
.about { background: var(--gray); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.about-heading { display: flex; align-items: center; gap: 0.8rem; margin-bottom: 1.5rem; }
.about-heading h2 { font-size: 1.2rem; font-weight: 700; color: var(--dark); }
.about-body { display: grid; grid-template-columns: 1fr 280px; gap: 2rem; align-items: start; }
.about-text p { margin-bottom: 1rem; font-size: 0.93rem; line-height: 1.85; }
.about-text p:last-child { margin-bottom: 0; }
.emphasis { color: var(--orange); font-weight: 700; }

.info-box { background: var(--blue-lt); border: 1px solid #bdd6f0; border-radius: var(--radius); padding: 1.2rem; }
.info-box-title {
  display: flex; align-items: center; gap: 0.5rem;
  font-weight: 700; color: var(--blue); margin-bottom: 0.7rem; font-size: 0.9rem;
}
.info-box p { font-size: 0.85rem; color: #2c5282; line-height: 1.7; }

/* ===== 開催期間 ===== */
.period { background: var(--white); border-bottom: 1px solid var(--border); }
.period-inner { text-align: center; padding-top: 3rem; padding-bottom: 3rem; }
.period-label {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-size: 0.9rem; font-weight: 700; color: var(--muted); margin-bottom: 1rem;
}
.period-date { font-size: clamp(1.5rem, 4vw, 2.5rem); font-weight: 900; color: var(--dark); line-height: 1.3; }
.dow { color: var(--orange); font-size: 0.7em; }
.period-note { margin-top: 0.8rem; font-size: 0.9rem; color: var(--muted); }

/* ===== 参加方法 ===== */
.how { background: var(--gray); border-bottom: 1px solid var(--border); }
.steps { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr; gap: 0.5rem; align-items: stretch; }
.step-arrow { display: flex; align-items: center; font-size: 1.5rem; color: var(--orange); padding: 0 0.5rem; font-weight: 700; }
.step {
  background: var(--white); border: 2px solid var(--border); border-radius: var(--radius);
  padding: 1.5rem; display: flex; gap: 0.8rem;
}
.step.step-highlight { border-color: var(--orange); background: var(--orange-lt); }
.step-num {
  width: 32px; height: 32px; background: var(--orange); color: #fff;
  font-weight: 900; font-size: 1rem; border-radius: 50%;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.step-content h3 { font-size: 0.95rem; font-weight: 700; margin-bottom: 0.6rem; color: var(--dark); }
.step-content p  { font-size: 0.82rem; color: var(--muted); line-height: 1.65; }
.tag-chip {
  display: inline-flex; align-items: center; gap: 0.4rem;
  background: var(--white); border: 2px solid var(--orange); color: var(--dark);
  font-size: 0.8rem; font-weight: 700; padding: 6px 10px; border-radius: 6px; margin-bottom: 0.6rem;
}

/* ===== カテゴリ ===== */
.category { background: var(--white); border-bottom: 1px solid var(--border); }
.cat-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 1rem; }
.cat-card {
  background: var(--white); border: 1.5px solid var(--border); border-radius: var(--radius);
  padding: 1.2rem 0.8rem; text-align: center; box-shadow: var(--shadow);
  transition: border-color 0.15s, transform 0.15s, box-shadow 0.15s;
}
.cat-card:hover { border-color: var(--orange); transform: translateY(-2px); box-shadow: 0 6px 16px rgba(255,102,0,0.1); }
.cat-card h3 { font-size: 0.9rem; font-weight: 700; margin-bottom: 0.4rem; color: var(--dark); }
.cat-card p  { font-size: 0.75rem; color: var(--muted); line-height: 1.55; }

/* ===== FAQ ===== */
.faq { background: var(--gray); border-bottom: 1px solid var(--border); }
.faq-list { display: flex; flex-direction: column; gap: 0.5rem; }
.faq-item { background: var(--white); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.faq-item summary {
  padding: 1rem 1.2rem; font-weight: 700; font-size: 0.9rem; cursor: pointer;
  list-style: none; display: flex; justify-content: space-between; align-items: center;
  transition: color 0.15s;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: '＋'; color: var(--orange); font-size: 1.1rem; flex-shrink: 0; }
.faq-item[open] summary::after { content: '－'; }
.faq-item summary:hover { color: var(--orange); }
.faq-item p { padding: 0.8rem 1.2rem 1rem; font-size: 0.88rem; color: var(--muted); line-height: 1.7; border-top: 1px solid var(--border); }

/* ===== フッター ===== */
.site-footer { background: #1a1a1a; color: #ccc; }
.footer-inner {
  max-width: 1000px; margin: 0 auto; padding: 3rem 1.5rem 2rem;
  display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 2rem;
}
.footer-col h4 { font-size: 0.82rem; color: #fff; margin-bottom: 0.8rem; font-weight: 700; }
.footer-col ul { display: flex; flex-direction: column; gap: 0.4rem; }
.footer-col li a { font-size: 0.8rem; color: #aaa; transition: color 0.15s; }
.footer-col li a:hover { color: var(--orange); }
.footer-col li a.disabled { color: #666; cursor: default; pointer-events: none; }
.footer-sns .sns-icons { display: flex; gap: 0.7rem; margin-top: 0.3rem; }
.sns-icon-btn {
  width: 44px; height: 44px; background: #333; border-radius: 8px;
  display: flex; align-items: center; justify-content: center; color: #fff;
  transition: background 0.15s;
}
.sns-icon-btn:hover { background: var(--orange); }
.footer-bottom {
  border-top: 1px solid #333; padding: 1.2rem 1.5rem;
  text-align: center; display: flex; flex-direction: column; gap: 0.3rem;
}
.footer-bottom p { font-size: 0.72rem; color: #666; }

/* ===== レスポンシブ ===== */
@media (max-width: 900px) {
  .cat-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 768px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-visual { display: none; }
  .about-body { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr; }
  .step-arrow { display: none; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .nico-nav { display: none; }
  .event-nav { display: none; }
}
@media (max-width: 480px) {
  .cat-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr; }
}