/* ==========================================================================
   2026 短视频创作大会 ContentVision Summit
   style.css - 全站样式（深色主题 · 响应式 · 动画）
   ========================================================================== */

/* ---------- 1. 设计变量 ---------- */
:root {
  --bg: #0b0d17;
  --bg-2: #0e1122;
  --bg-3: #131730;
  --surface: rgba(255, 255, 255, 0.045);
  --surface-hover: rgba(255, 255, 255, 0.08);
  --border: rgba(255, 255, 255, 0.09);
  --text: #eef0ff;
  --muted: #9aa3bd;
  --primary: #7c5cff;
  --accent: #4dd6ff;
  --grad: linear-gradient(135deg, #7c5cff 0%, #4dd6ff 100%);
  --danger: #ff6b81;
  --success: #3fe0a5;
  --radius: 18px;
  --radius-sm: 12px;
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.45);
  --shadow-glow: 0 10px 40px rgba(124, 92, 255, 0.35);
  --header-h: 72px;
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Segoe UI", system-ui, -apple-system, sans-serif;
}

/* ---------- 2. 重置与基础 ---------- */
*,
*::before,
*::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 12px);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
}

img, video, svg { display: block; max-width: 100%; }
img { height: auto; }

a { color: inherit; text-decoration: none; transition: color 0.25s ease; }
a:hover { color: var(--accent); }

ul, ol { list-style: none; }

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

::selection { background: rgba(124, 92, 255, 0.45); color: #fff; }

/* 自定义滚动条（桌面端） */
::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, #7c5cff, #4dd6ff);
  border-radius: 8px;
  border: 2px solid var(--bg);
}

/* ---------- 3. 通用工具类 ---------- */
.container {
  width: min(1180px, 92%);
  margin-inline: auto;
}

.skip-link {
  position: absolute;
  top: -60px;
  left: 16px;
  z-index: 999;
  background: var(--primary);
  color: #fff;
  padding: 10px 18px;
  border-radius: 0 0 10px 10px;
  transition: top 0.25s ease;
}
.skip-link:focus { top: 0; color: #fff; }

.grad-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.only-mobile { display: none; }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 30px;
  border-radius: 999px;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease, color 0.25s ease;
  will-change: transform;
}
.btn svg { width: 18px; height: 18px; }

.btn-primary {
  background: var(--grad);
  color: #fff;
  box-shadow: var(--shadow-glow);
}
.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 16px 50px rgba(124, 92, 255, 0.5);
  color: #fff;
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border);
  color: var(--text);
  backdrop-filter: blur(8px);
}
.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.12);
  transform: translateY(-3px);
  color: #fff;
}

.btn-block { width: 100%; }

/* 区块标题 */
.section { padding: 96px 0; position: relative; }
.section-alt { background: var(--bg-2); }

.section-head {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 56px;
}
.section-tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 10px;
}
.section-title {
  font-size: clamp(1.7rem, 4vw, 2.4rem);
  font-weight: 800;
  letter-spacing: 0.01em;
  margin-bottom: 12px;
}
.section-desc { color: var(--muted); font-size: 1.02rem; }

/* 滚动进入动画（配合 JS 的 IntersectionObserver） */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 4. 顶部导航 ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 100;
  height: var(--header-h);
  transition: background 0.3s ease, box-shadow 0.3s ease, backdrop-filter 0.3s ease;
}
.site-header.is-scrolled {
  background: rgba(11, 13, 23, 0.82);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: 0 1px 0 var(--border), 0 12px 30px rgba(0, 0, 0, 0.35);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
}
.brand:hover { color: var(--text); }
.brand-logo { width: 36px; height: 36px; flex: none; }
.brand-text {
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  line-height: 1;
}
.brand-text em {
  display: block;
  font-style: normal;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--muted);
  margin-top: 4px;
}

.site-nav ul {
  display: flex;
  align-items: center;
  gap: 6px;
}
.nav-link {
  display: inline-block;
  padding: 9px 16px;
  border-radius: 999px;
  font-size: 0.95rem;
  color: var(--muted);
  transition: color 0.25s ease, background 0.25s ease;
}
.nav-link:hover { color: var(--text); background: var(--surface-hover); }

/* 滚动监听高亮当前分区 */
.nav-link.is-active { color: var(--text); background: var(--surface-hover); }

.btn-nav {
  background: var(--grad);
  color: #fff !important;
  font-weight: 600;
  box-shadow: 0 6px 22px rgba(124, 92, 255, 0.4);
}
.btn-nav:hover { color: #fff; }

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  border-radius: 10px;
  padding: 10px;
}
.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}
.nav-toggle.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 5. 首屏 Hero ---------- */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  padding: calc(var(--header-h) + 40px) 0 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: url("../images/hero-banner.png") center / cover no-repeat;
  transform: scale(1.06);
  animation: heroZoom 18s ease-in-out infinite alternate;
}
@keyframes heroZoom {
  from { transform: scale(1.06); }
  to   { transform: scale(1.14); }
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 20% 30%, rgba(124, 92, 255, 0.35), transparent 55%),
    radial-gradient(ellipse at 80% 75%, rgba(77, 214, 255, 0.22), transparent 55%),
    linear-gradient(180deg, rgba(11, 13, 23, 0.55) 0%, rgba(11, 13, 23, 0.72) 60%, var(--bg) 100%);
}

.hero-inner {
  position: relative;
  z-index: 2;
  text-align: center;
}

.hero-kicker {
  display: inline-block;
  padding: 8px 20px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(6px);
  font-size: 0.9rem;
  letter-spacing: 0.12em;
  color: var(--accent);
  margin-bottom: 26px;
}

.hero-title {
  font-size: clamp(2.3rem, 7vw, 4.4rem);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: 0.02em;
  margin-bottom: 20px;
  text-shadow: 0 6px 40px rgba(0, 0, 0, 0.55);
}

.hero-subtitle {
  font-size: clamp(1rem, 2.4vw, 1.2rem);
  color: rgba(238, 240, 255, 0.82);
  margin-bottom: 30px;
}

.hero-meta {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 36px;
}
.meta-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(6px);
  font-size: 0.95rem;
}
.meta-chip svg { width: 18px; height: 18px; color: var(--accent); }

/* 倒计时 */
.countdown {
  display: inline-flex;
  gap: 14px;
  margin-bottom: 40px;
}
.countdown-item {
  min-width: 84px;
  padding: 14px 10px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  text-align: center;
}
.countdown-item strong {
  display: block;
  font-size: 1.9rem;
  font-weight: 800;
  line-height: 1.15;
  font-variant-numeric: tabular-nums;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.countdown-item span {
  font-size: 0.78rem;
  color: var(--muted);
  letter-spacing: 0.18em;
}

.hero-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
}

/* 向下滚动提示 */
.hero-scroll {
  position: absolute;
  left: 50%;
  bottom: 26px;
  transform: translateX(-50%);
  width: 26px;
  height: 44px;
  border: 2px solid rgba(255, 255, 255, 0.35);
  border-radius: 999px;
  z-index: 2;
}
.hero-scroll span {
  position: absolute;
  left: 50%;
  top: 8px;
  width: 4px;
  height: 8px;
  margin-left: -2px;
  border-radius: 4px;
  background: var(--accent);
  animation: scrollHint 1.8s ease-in-out infinite;
}
@keyframes scrollHint {
  0%   { transform: translateY(0); opacity: 1; }
  70%  { transform: translateY(14px); opacity: 0; }
  100% { transform: translateY(0); opacity: 0; }
}

/* ---------- 6. 活动简介 ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 56px;
  align-items: center;
}
.about-text p { color: var(--muted); margin-bottom: 18px; font-size: 1.02rem; }
.about-text strong { color: var(--text); }
.about-text em { color: var(--accent); font-style: normal; }

.about-points { margin-top: 26px; }
.about-points li {
  position: relative;
  padding-left: 30px;
  margin-bottom: 12px;
  color: var(--text);
}
.about-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.5em;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--grad);
  clip-path: polygon(35% 62%, 30% 40%, 62% 62%, 90% 25%, 95% 45%, 62% 78%);
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}
.stat-card {
  padding: 28px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: linear-gradient(160deg, rgba(124, 92, 255, 0.14), rgba(77, 214, 255, 0.06));
  text-align: center;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.stat-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow);
}
.stat-card strong {
  font-size: 2.1rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
}
.stat-card > span {
  font-size: 1.3rem;
  font-weight: 800;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.stat-card p { color: var(--muted); font-size: 0.92rem; margin-top: 4px; }

/* ---------- 7. 活动亮点 ---------- */
.highlight-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
.highlight-card {
  padding: 32px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  transition: transform 0.35s ease, border-color 0.35s ease, background 0.35s ease, box-shadow 0.35s ease;
}
.highlight-card:hover {
  transform: translateY(-8px);
  border-color: rgba(124, 92, 255, 0.5);
  background: var(--surface-hover);
  box-shadow: var(--shadow);
}
.highlight-card .icon {
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  background: var(--grad);
  margin-bottom: 20px;
  box-shadow: 0 8px 24px rgba(124, 92, 255, 0.35);
}
.highlight-card .icon svg { width: 28px; height: 28px; color: #fff; }
.highlight-card h3 { font-size: 1.18rem; margin-bottom: 10px; }
.highlight-card p { color: var(--muted); font-size: 0.95rem; }

/* ---------- 8. 精彩图集 ---------- */
.gallery-filter {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 36px;
}
.filter-btn {
  padding: 9px 22px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--muted);
  font-size: 0.92rem;
  transition: all 0.25s ease;
}
.filter-btn:hover { color: var(--text); background: var(--surface-hover); }
.filter-btn.is-active {
  background: var(--grad);
  border-color: transparent;
  color: #fff;
  font-weight: 600;
  box-shadow: 0 6px 22px rgba(124, 92, 255, 0.4);
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}
.gallery-item {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  cursor: zoom-in;
  border: 1px solid var(--border);
  background: var(--bg-3);
}
.gallery-item.is-hidden { display: none; }

.gallery-item img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  transition: transform 0.6s cubic-bezier(0.22, 0.61, 0.36, 1), filter 0.4s ease;
}
.gallery-item:hover img {
  transform: scale(1.08);
  filter: brightness(0.75);
}
.gallery-item::after {
  content: "+";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.6);
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: rgba(124, 92, 255, 0.85);
  color: #fff;
  font-size: 1.6rem;
  font-weight: 300;
  opacity: 0;
  transition: opacity 0.35s ease, transform 0.35s ease;
  pointer-events: none;
}
.gallery-item:hover::after {
  opacity: 1;
  transform: translate(-50%, -50%) scale(1);
}

.gallery-item figcaption {
  position: absolute;
  inset: auto 0 0 0;
  padding: 40px 18px 14px;
  background: linear-gradient(180deg, transparent, rgba(11, 13, 23, 0.92));
  font-size: 0.9rem;
  color: rgba(238, 240, 255, 0.9);
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.gallery-item figcaption span {
  flex: none;
  font-size: 0.72rem;
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(124, 92, 255, 0.9);
  color: #fff;
  letter-spacing: 0.08em;
}

/* 灯箱 */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  padding: 5vh 4vw;
  background: rgba(5, 6, 12, 0.92);
  backdrop-filter: blur(10px);
  animation: fadeIn 0.3s ease;
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

.lightbox-content {
  max-width: min(1000px, 88vw);
  text-align: center;
}
.lightbox-content img {
  max-height: 76vh;
  width: auto;
  margin-inline: auto;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow);
}
.lightbox-content figcaption {
  margin-top: 16px;
  color: rgba(238, 240, 255, 0.85);
  font-size: 0.95rem;
}

.lightbox-close {
  position: absolute;
  top: 22px;
  right: 26px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  font-size: 1.9rem;
  line-height: 1;
  color: var(--text);
  background: rgba(255, 255, 255, 0.08);
  transition: background 0.25s ease, transform 0.25s ease;
}
.lightbox-close:hover { background: rgba(255, 255, 255, 0.18); transform: rotate(90deg); }

.lightbox-nav {
  flex: none;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  font-size: 2rem;
  line-height: 1;
  color: var(--text);
  background: rgba(255, 255, 255, 0.08);
  transition: background 0.25s ease, transform 0.25s ease;
}
.lightbox-nav:hover { background: var(--primary); transform: scale(1.08); }

/* ---------- 9. 宣传视频 ---------- */
.video-layout {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 40px;
  align-items: start;
}

.video-player {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: #000;
  box-shadow: var(--shadow);
  aspect-ratio: 16 / 9;
}
.video-player video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-play-btn {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  width: 100%;
  height: 100%;
  background: linear-gradient(180deg, rgba(11, 13, 23, 0.1), rgba(11, 13, 23, 0.45));
  transition: background 0.3s ease;
}
.video-play-btn:hover { background: linear-gradient(180deg, rgba(11, 13, 23, 0.2), rgba(11, 13, 23, 0.55)); }
.video-play-btn svg {
  width: 34px;
  height: 34px;
  color: #fff;
  position: relative;
  z-index: 2;
  margin-left: 4px;
}
.video-play-btn .play-ring {
  position: absolute;
  width: 96px;
  height: 96px;
  border-radius: 50%;
  background: var(--grad);
  box-shadow: 0 0 0 0 rgba(124, 92, 255, 0.5);
  animation: playPulse 2.2s ease-out infinite;
}
@keyframes playPulse {
  0%   { box-shadow: 0 0 0 0 rgba(124, 92, 255, 0.55); }
  100% { box-shadow: 0 0 0 34px rgba(124, 92, 255, 0); }
}
.video-play-btn.is-hidden { display: none; }

/* 自定义控制条 */
.video-controls {
  position: absolute;
  inset: auto 0 0 0;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 26px 18px 14px;
  background: linear-gradient(180deg, transparent, rgba(5, 6, 12, 0.88));
  z-index: 3;
}
.vc-btn {
  width: 38px;
  height: 38px;
  flex: none;
  display: grid;
  place-items: center;
  border-radius: 10px;
  color: #fff;
  transition: background 0.25s ease;
}
.vc-btn:hover { background: rgba(255, 255, 255, 0.14); }
.vc-btn svg { width: 22px; height: 22px; }
.vc-btn .ic-pause { display: none; }
.video-player.is-playing .vc-btn .ic-play { display: none; }
.video-player.is-playing .vc-btn .ic-pause { display: block; }
.video-player.is-muted .vc-btn#vcMute { opacity: 0.5; }

.vc-progress {
  flex: 1;
  height: 6px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.2);
  cursor: pointer;
  overflow: hidden;
}
.vc-progress-bar {
  width: 0%;
  height: 100%;
  border-radius: 999px;
  background: var(--grad);
  transition: width 0.15s linear;
}
.vc-time {
  flex: none;
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.85);
  font-variant-numeric: tabular-nums;
}

.video-toast {
  position: absolute;
  left: 50%;
  bottom: 76px;
  transform: translateX(-50%);
  z-index: 4;
  max-width: 92%;
  padding: 12px 20px;
  border-radius: 12px;
  background: rgba(11, 13, 23, 0.92);
  border: 1px solid rgba(124, 92, 255, 0.5);
  font-size: 0.85rem;
  color: var(--text);
  text-align: center;
  animation: fadeIn 0.3s ease;
}
.video-toast code {
  color: var(--accent);
  background: rgba(77, 214, 255, 0.12);
  padding: 1px 6px;
  border-radius: 5px;
}

/* 视频信息侧栏 */
.video-info {
  padding: 30px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
}
.video-info h3 { font-size: 1.25rem; margin-bottom: 16px; }
.video-info h4 { font-size: 1rem; margin: 24px 0 12px; }
.video-info h4 small { color: var(--muted); font-weight: 400; font-size: 0.78rem; }

.video-points li {
  position: relative;
  padding-left: 22px;
  margin-bottom: 10px;
  color: var(--muted);
  font-size: 0.94rem;
}
.video-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--grad);
}
.video-points strong { color: var(--text); }

.chapter-list { counter-reset: chapter; }
.chapter-list li { margin-bottom: 8px; }
.chapter-list button {
  width: 100%;
  text-align: left;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
  color: var(--muted);
  font-size: 0.9rem;
  transition: all 0.25s ease;
}
.chapter-list button:hover {
  color: var(--text);
  border-color: rgba(77, 214, 255, 0.55);
  background: rgba(77, 214, 255, 0.08);
  transform: translateX(4px);
}

.video-info .btn { margin-top: 26px; }

/* ---------- 10. 大会议程时间轴 ---------- */
.timeline {
  position: relative;
  max-width: 760px;
  margin: 0 auto;
  padding-left: 34px;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--primary), var(--accent), transparent);
}
.timeline-item {
  position: relative;
  display: grid;
  grid-template-columns: 86px 1fr;
  gap: 18px;
  margin-bottom: 24px;
}
.timeline-item::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 10px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bg);
  border: 3px solid var(--primary);
  box-shadow: 0 0 14px rgba(124, 92, 255, 0.7);
}
.timeline-item time {
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--accent);
  padding-top: 8px;
}
.timeline-card {
  padding: 18px 22px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  transition: transform 0.3s ease, border-color 0.3s ease, background 0.3s ease;
}
.timeline-card:hover {
  transform: translateX(6px);
  border-color: rgba(77, 214, 255, 0.4);
  background: var(--surface-hover);
}
.timeline-card h3 { font-size: 1.08rem; margin-bottom: 6px; }
.timeline-card p { color: var(--muted); font-size: 0.92rem; }

/* ---------- 11. 报名表单 ---------- */
.cta-section {
  background:
    radial-gradient(ellipse at 15% 20%, rgba(124, 92, 255, 0.22), transparent 50%),
    radial-gradient(ellipse at 85% 80%, rgba(77, 214, 255, 0.16), transparent 50%),
    var(--bg-2);
}

.register-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 56px;
  padding: 56px;
  border-radius: 26px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.035);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow);
}

.register-info .section-tag { margin-bottom: 8px; }
.register-info .section-title { text-align: left; }
.register-info > p { color: var(--muted); margin: 14px 0 22px; }

.register-perks li {
  position: relative;
  padding-left: 30px;
  margin-bottom: 12px;
}
.register-perks li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.35em;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: rgba(63, 224, 165, 0.15);
  border: 1px solid rgba(63, 224, 165, 0.6);
}
.register-perks li::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 0.62em;
  width: 8px;
  height: 4px;
  border-left: 2px solid var(--success);
  border-bottom: 2px solid var(--success);
  transform: rotate(-45deg);
}

/* 表单字段 */
.register-form { display: flex; flex-direction: column; gap: 18px; }
.form-field { display: flex; flex-direction: column; gap: 8px; }
.form-field label {
  font-size: 0.92rem;
  font-weight: 600;
}
.form-field label span { color: var(--danger); }

.form-field input,
.form-field select {
  width: 100%;
  padding: 13px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: rgba(11, 13, 23, 0.6);
  color: var(--text);
  font-size: 0.96rem;
  font-family: inherit;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}
.form-field input::placeholder { color: rgba(154, 163, 189, 0.6); }
.form-field input:focus,
.form-field select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(124, 92, 255, 0.25);
}
.form-field select option { background: var(--bg-2); color: var(--text); }

.form-field.has-error input,
.form-field.has-error select { border-color: var(--danger); }
.field-error {
  font-size: 0.8rem;
  color: var(--danger);
  min-height: 1em;
  line-height: 1.2;
}

.form-note { font-size: 0.78rem; color: var(--muted); text-align: center; }

.form-success {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 16px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(63, 224, 165, 0.5);
  background: rgba(63, 224, 165, 0.1);
  animation: fadeIn 0.4s ease;
}
.form-success svg { width: 26px; height: 26px; flex: none; color: var(--success); }
.form-success p { font-size: 0.92rem; }
.form-success strong { color: var(--success); }

/* ---------- 12. 页脚 ---------- */
.site-footer {
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding: 64px 0 30px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1.2fr;
  gap: 44px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--border);
}
.footer-brand p { color: var(--muted); font-size: 0.92rem; margin-top: 16px; }
.footer-links h3,
.footer-contact h3 {
  font-size: 1rem;
  margin-bottom: 16px;
  letter-spacing: 0.04em;
}
.footer-links li { margin-bottom: 10px; }
.footer-links a { color: var(--muted); font-size: 0.92rem; }
.footer-links a:hover { color: var(--accent); }
.footer-contact li { color: var(--muted); font-size: 0.92rem; margin-bottom: 10px; }
.footer-contact a { color: var(--accent); }

.footer-bottom {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  padding-top: 26px;
  color: rgba(154, 163, 189, 0.75);
  font-size: 0.82rem;
}

/* ---------- 13. 响应式 ---------- */
@media (max-width: 1024px) {
  .highlight-grid { grid-template-columns: repeat(2, 1fr); }
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .video-layout { grid-template-columns: 1fr; }
  .register-card { grid-template-columns: 1fr; gap: 38px; padding: 40px 30px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 820px) {
  .only-mobile { display: inline; }

  /* 移动端导航抽屉 */
  .nav-toggle { display: flex; }
  .site-nav {
    position: fixed;
    top: var(--header-h);
    right: 0;
    left: 0;
    background: rgba(11, 13, 23, 0.97);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
  }
  .site-nav.is-open { max-height: 420px; }
  .site-nav ul {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 16px 4% 22px;
  }
  .nav-link {
    display: block;
    padding: 13px 18px;
    font-size: 1rem;
  }
  .btn-nav { text-align: center; margin-top: 6px; }

  .section { padding: 72px 0; }

  .countdown-item { min-width: 68px; padding: 12px 6px 8px; }
  .countdown-item strong { font-size: 1.5rem; }

  .gallery-grid { grid-template-columns: repeat(2, 1fr); }

  .lightbox-nav { position: absolute; top: 50%; transform: translateY(-50%); }
  .lightbox-prev { left: 12px; }
  .lightbox-next { right: 12px; }
  .lightbox-content img { max-height: 66vh; }

  .timeline-item { grid-template-columns: 1fr; gap: 6px; }
  .timeline-item time { padding-top: 0; }
}

@media (max-width: 560px) {
  .hero { min-height: auto; padding-top: calc(var(--header-h) + 56px); }
  .hero-scroll { display: none; }
  .hero-actions .btn { width: 100%; }
  .countdown { gap: 8px; }
  .countdown-item { flex: 1; min-width: 0; }

  .highlight-grid { grid-template-columns: 1fr; }
  .gallery-grid { grid-template-columns: 1fr; }
  .about-stats { gap: 12px; }
  .stat-card { padding: 20px 12px; }

  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
  .footer-bottom { flex-direction: column; }
}

/* ---------- 14. 动效偏好与打印 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  .reveal { opacity: 1; transform: none; }
}