/* ============================================================
   通用活动邀请函 · 样式
   配色：深空蓝金系 #0d1117 背景 / #6c63ff 主色 / #f0c040 金色
   ============================================================ */

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { font-size: 16px; -webkit-text-size-adjust: 100%; }
body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #f0f2ff;
  color: #1a1a2e;
  overflow-x: hidden;
  min-height: 100vh;
}
img { display: block; width: 100%; height: auto; object-fit: cover; }

/* ---- 封面 ---- */
.cover {
  position: fixed; inset: 0; z-index: 200;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; overflow: hidden;
  transition: opacity .9s ease, transform .9s ease;
}
.cover.hide { opacity: 0; transform: scale(1.05); pointer-events: none; }
.cover-bg {
  position: absolute; inset: 0;
  background: linear-gradient(160deg, #0d1117 0%, #1a1a2e 50%, #16213e 100%);
}

/* 几何装饰 */
.geo {
  position: absolute;
  border: 1px solid rgba(108,99,255,.3);
  border-radius: 50%;
  animation: geoRotate 20s linear infinite;
}
.geo-1 { width: 200px; height: 200px; top: -50px; right: -50px; }
.geo-2 { width: 300px; height: 300px; bottom: -100px; left: -100px; border-color: rgba(240,192,64,.2); animation-direction: reverse; animation-duration: 30s; }
.geo-3 { width: 100px; height: 100px; bottom: 20%; right: 10%; border-color: rgba(108,99,255,.4); animation-duration: 15s; }
@keyframes geoRotate { to { transform: rotate(360deg); } }

.cover-inner {
  position: relative; z-index: 1;
  text-align: center; padding: 0 2rem;
  animation: coverFadeIn 1s ease both;
}
@keyframes coverFadeIn { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: none; } }

.cover-logo {
  position: relative; width: 80px; height: 80px; margin: 0 auto 1.2rem;
  display: flex; align-items: center; justify-content: center;
}
.logo-ring {
  position: absolute; inset: 0; border-radius: 50%;
  border: 2px solid #6c63ff;
  animation: spinSlow 6s linear infinite;
  border-top-color: #f0c040;
}
@keyframes spinSlow { to { transform: rotate(360deg); } }
.logo-text { font-size: 1.2rem; font-weight: 700; color: #f0c040; letter-spacing: .05em; }

.cover-title { font-size: 2rem; font-weight: 400; color: #fff; letter-spacing: .3em; }
.cover-subtitle { font-size: .75rem; color: #6c63ff; letter-spacing: .2em; margin: .3rem 0 .8rem; text-transform: uppercase; }
.cover-org { font-size: .9rem; color: rgba(255,255,255,.7); letter-spacing: .08em; margin-bottom: .4rem; }
.cover-date { font-size: .85rem; color: #f0c040; letter-spacing: .25em; }

.cover-tap-hint {
  display: flex; align-items: center; gap: .6rem;
  margin-top: 1.8rem; color: rgba(255,255,255,.5); font-size: .8rem;
  animation: breathe 2s ease-in-out infinite;
}
.tap-line { flex: 1; height: 1px; background: rgba(108,99,255,.4); max-width: 50px; }
@keyframes breathe { 0%, 100% { opacity: .4; } 50% { opacity: 1; } }

/* ---- 主体 ---- */
.invitation { max-width: 640px; margin: 0 auto; padding-bottom: 4rem; display: none; }
.section { padding: 0 0 2rem; }

.hero { padding: 0; }
.hero-frame { position: relative; overflow: hidden; }
.hero-img { width: 100%; max-height: 380px; object-fit: cover; }
.hero-overlay {
  position: absolute; bottom: 0; left: 0; right: 0;
  background: linear-gradient(to top, rgba(13,17,23,.8), transparent);
  padding: 1.5rem 1.5rem .8rem;
}
.hero-tag { color: rgba(255,255,255,.8); font-size: .7rem; letter-spacing: .35em; text-align: center; text-transform: uppercase; }

.title-block { text-align: center; padding: 2.5rem 1.5rem 2rem; }
.badge {
  display: inline-block; padding: .3rem 1rem;
  background: linear-gradient(135deg, #6c63ff, #4a42d0);
  color: #fff; font-size: .7rem; letter-spacing: .2em; border-radius: 20px;
  margin-bottom: 1rem;
}
.main-title { font-size: 2.2rem; font-weight: 500; color: #1a1a2e; letter-spacing: .1em; }
.sub-title { font-size: .9rem; color: #6c63ff; letter-spacing: .1em; margin: .5rem 0; }
.title-divider {
  display: flex; align-items: center; gap: .6rem;
  margin: 1rem auto; width: 180px;
}
.title-divider span { flex: 1; height: 1px; background: linear-gradient(to right, transparent, #6c63ff, transparent); }
.title-divider em { color: #f0c040; font-style: normal; font-size: .7rem; }
.event-date { font-size: 1rem; color: #6c63ff; letter-spacing: .08em; }

.intro { padding: 0 1.5rem 2rem; }
.intro-card {
  background: linear-gradient(135deg, #f5f4ff, #fffdf0);
  border-radius: 16px; padding: 2rem 1.5rem;
  border: 1px solid rgba(108,99,255,.15);
  box-shadow: 0 4px 20px rgba(108,99,255,.08);
}
.intro-title {
  text-align: center; font-size: 1.1rem; color: #6c63ff;
  letter-spacing: .1em; margin-bottom: 1rem;
}
.intro-title::after {
  content: ''; display: block; width: 40px; height: 2px;
  background: linear-gradient(to right, #6c63ff, #f0c040);
  margin: .5rem auto 0; border-radius: 2px;
}
.intro-text { line-height: 2.2; font-size: .95rem; color: #4a4a6a; text-align: center; }

/* 时间线 */
.agenda { padding: 0 1.5rem 2rem; }
.agenda-card {
  background: #fff; border-radius: 16px; padding: 2rem 1.5rem;
  box-shadow: 0 4px 24px rgba(108,99,255,.1);
  border: 1px solid rgba(108,99,255,.12);
}
.agenda-title {
  text-align: center; font-size: 1.1rem; color: #6c63ff;
  letter-spacing: .15em; margin-bottom: 1.5rem;
}
.timeline { display: flex; flex-direction: column; gap: 0; }
.timeline-item {
  display: flex; gap: 1rem; align-items: flex-start;
  padding: .8rem 0;
  border-bottom: 1px solid rgba(108,99,255,.1);
  position: relative;
}
.timeline-item:last-child { border-bottom: none; }
.timeline-item::before {
  content: '';
  position: absolute; left: 58px; top: 0; bottom: -1px;
  width: 2px; background: linear-gradient(to bottom, rgba(108,99,255,.3), transparent);
}
.timeline-item:last-child::before { display: none; }
.time-badge {
  min-width: 56px;
  background: linear-gradient(135deg, #6c63ff, #4a42d0);
  color: #fff; font-size: .75rem; font-weight: 600; letter-spacing: .05em;
  border-radius: 20px; padding: .25rem .5rem; text-align: center;
  flex-shrink: 0; position: relative; z-index: 1;
}
.time-content { flex: 1; }
.time-content strong { display: block; font-size: .95rem; color: #1a1a2e; margin-bottom: .2rem; }
.time-content p { font-size: .8rem; color: #6a6a8a; }

.details { padding: 0 1.5rem 2rem; }
.details-card {
  background: #fff; border-radius: 16px; padding: 2rem 1.5rem;
  box-shadow: 0 4px 24px rgba(108,99,255,.08);
  border: 1px solid rgba(108,99,255,.12);
}
.details-title {
  text-align: center; font-size: 1.1rem; color: #6c63ff;
  letter-spacing: .15em; margin-bottom: 1.5rem;
}
.details-list { display: flex; flex-direction: column; gap: 1rem; }
.detail-item {
  display: flex; align-items: center; gap: 1rem;
  padding: .8rem; border-radius: 10px;
  background: linear-gradient(135deg, #f5f4ff, #fffdf0);
}
.detail-icon { font-size: 1.5rem; flex-shrink: 0; }
.detail-info { display: flex; flex-direction: column; gap: .15rem; }
.detail-label { font-size: .75rem; color: #9090b0; }
.detail-value { font-size: .9rem; color: #1a1a2e; font-weight: 500; }

.ending { padding: 0 1.5rem 3rem; }
.ending-inner { text-align: center; }
.ending-line {
  height: 1px; margin: 1rem auto;
  background: linear-gradient(to right, transparent, #6c63ff 30%, #f0c040 70%, transparent);
  max-width: 200px;
}
.ending-text { font-size: 1.05rem; color: #4a4a6a; line-height: 1.8; margin-bottom: .8rem; }
.ending-sign { font-size: .9rem; color: #6c63ff; letter-spacing: .1em; }

/* ---- 音乐按钮 ---- */
.music-btn {
  position: fixed; right: 1rem; top: 1rem; z-index: 300;
  width: 48px; height: 48px; cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}
.music-disc {
  width: 100%; height: 100%; border-radius: 50%;
  background: linear-gradient(135deg, #6c63ff, #4a42d0);
  box-shadow: 0 3px 12px rgba(108,99,255,.4);
  display: flex; align-items: center; justify-content: center;
}
.music-note { color: #fff; font-size: 1.3rem; }
.music-btn.playing .music-disc { animation: discSpin 4s linear infinite; }
@keyframes discSpin { to { transform: rotate(360deg); } }

/* ---- 滚动动画 ---- */
.animate { opacity: 0; transition: opacity .8s cubic-bezier(.4,0,.2,1), transform .8s cubic-bezier(.4,0,.2,1); will-change: opacity, transform; }
.animate[data-anim="fade-down"]  { transform: translateY(-50px); }
.animate[data-anim="fade-up"]    { transform: translateY(50px);  }
.animate[data-anim="zoom-in"]    { transform: scale(.85);        }
.animate[data-anim="slide-left"] { transform: translateX(-60px); }
.animate[data-anim="slide-right"]{ transform: translateX(60px);  }
.animate.in { opacity: 1 !important; transform: none !important; }