/* =============================================
   文革项目 - 数字展陈系统
   主样式表
   ============================================= */

/* === Reset & Base === */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  height: 100%;
}

body {
  font-family: 'Microsoft YaHei', 'PingFang SC', 'Noto Sans SC', sans-serif;
  background: #0d0505;
  width: 100%;
  height: 100vh;
  /* 动态视口单位：移动端横屏可规避地址栏导致的高度偏差 */
  height: 100dvh;
  overflow: hidden;
  overflow-x: hidden;
  user-select: none;
  -webkit-user-select: none;
  /* 触摸优化：消除300ms延迟，禁止双击缩放 */
  touch-action: manipulation;
  -ms-touch-action: manipulation;
}

.container {
  display: flex;
  width: 100%;
  height: 100%;
  height: 100dvh;
  overflow-x: hidden;
}

/* =============================================
   左侧导航面板
   ============================================= */
.sidebar {
  width: 240px;
  min-width: 240px;
  background: linear-gradient(175deg, #7a1515 0%, #5f0e0e 35%, #450808 65%, #2a0404 100%);
  display: flex;
  flex-direction: column;
  border-right: 2px solid rgba(200, 152, 59, 0.55);
  position: relative;
  z-index: 10;
  box-shadow: 6px 0 30px rgba(0, 0, 0, 0.6), inset -2px 0 8px rgba(0, 0, 0, 0.3);
}

.sidebar::after {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    repeating-linear-gradient(
      0deg,
      transparent,
      transparent 3px,
      rgba(255, 255, 255, 0.008) 3px,
      rgba(255, 255, 255, 0.008) 6px
    ),
    radial-gradient(ellipse at 50% 0%, rgba(200, 152, 59, 0.06), transparent 70%);
  pointer-events: none;
}

/* --- 顶部标题 --- */
.header {
  padding: 24px 16px 14px;
  text-align: center;
  border-bottom: 1px solid rgba(200, 152, 59, 0.18);
  flex-shrink: 0;
  position: relative;
}

/* 标题顶部装饰线 */
.header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 56px;
  height: 2px;
  background: linear-gradient(90deg, transparent, #c8983b, transparent);
  border-radius: 2px;
}

/* 顶部五角星徽标 */
.header-emblem {
  display: flex;
  justify-content: center;
  margin-bottom: 14px;
}

.header-emblem-star {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, #e74c3c, #b71c1c);
  color: #f0d060;
  font-size: 14px;
  line-height: 1;
  clip-path: polygon(50% 0%, 61% 35%, 98% 35%, 68% 57%, 79% 91%, 50% 70%, 21% 91%, 32% 57%, 2% 35%, 39% 35%);
  text-shadow: 0 0 8px rgba(240, 208, 96, 0.6);
  box-shadow: 0 0 12px rgba(231, 76, 60, 0.4);
  animation: headerStarBreathe 4s ease-in-out infinite;
  position: relative;
}

/* 五角星外围旋转光芒 */
.header-emblem-star::after {
  content: '';
  position: absolute;
  top: -8px;
  left: -8px;
  right: -8px;
  bottom: -8px;
  border-radius: 50%;
  background: conic-gradient(from 0deg, transparent 0deg, rgba(240, 208, 96, 0.4) 30deg, transparent 60deg);
  animation: headerStarSpin 6s linear infinite;
  pointer-events: none;
  z-index: -1;
  will-change: transform;
}

@keyframes headerStarBreathe {
  0%, 100% { transform: scale(1); opacity: 0.9; }
  50%      { transform: scale(1.1); opacity: 1; }
}

@keyframes headerStarSpin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

.title-main {
  color: #f0d060;
  text-shadow: 0 0 20px rgba(200, 152, 59, 0.4), 0 2px 4px rgba(0, 0, 0, 0.5);
  position: relative;
  display: inline-block;
}

.title-line {
  font-size: 21px;
  font-weight: 900;
  letter-spacing: 3px;
  line-height: 1.35;
  white-space: nowrap;
}

/* 标题底部装饰 */
.title-main::after {
  content: '';
  position: absolute;
  bottom: -7px;
  left: 50%;
  transform: translateX(-50%);
  width: 70%;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(200, 152, 59, 0.5), transparent);
}

/* 小字副标题 */
.header-subtitle {
  margin-top: 14px;
  font-size: 13px;
  color: rgba(200, 152, 59, 0.65);
  letter-spacing: 5px;
  text-align: center;
}

/* 星星装饰条 */
.stars-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 10px;
  margin-top: 18px;
  padding: 4px 0;
}

.stars-row::before,
.stars-row::after {
  content: '';
  width: 32px;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(200, 152, 59, 0.45), transparent);
}

.star {
  width: 12px;
  height: 12px;
  background: #e74c3c;
  clip-path: polygon(50% 0%, 61% 35%, 98% 35%, 68% 57%, 79% 91%, 50% 70%, 21% 91%, 32% 57%, 2% 35%, 39% 35%);
  transition: all 0.3s ease;
}

.star:nth-child(1) { animation: starTwinkle 3.5s ease-in-out 0s infinite; }
.star:nth-child(2) { animation: starTwinkle 3.5s ease-in-out 0.4s infinite; }
.star:nth-child(3) { animation: starTwinkle 3.5s ease-in-out 0.8s infinite; width: 15px; height: 15px; }
.star:nth-child(4) { animation: starTwinkle 3.5s ease-in-out 1.2s infinite; }
.star:nth-child(5) { animation: starTwinkle 3.5s ease-in-out 1.6s infinite; }

@keyframes starTwinkle {
  0%, 100% { opacity: 0.85; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.08); }
}

/* --- 导航菜单 --- */
.nav-menu {
  flex: 1;
  overflow-y: auto;
  padding: 12px 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  /* GPU 加速滚动，消除卡顿 */
  transform: translateZ(0);
  -webkit-transform: translateZ(0);
  will-change: scroll-position;
}

.nav-menu::-webkit-scrollbar { width: 4px; }
.nav-menu::-webkit-scrollbar-track { background: transparent; }
.nav-menu::-webkit-scrollbar-thumb {
  background: rgba(200, 152, 59, 0.3);
  border-radius: 2px;
}

.nav-group {
  position: relative;
  contain: layout style;
}

/* 分组之间的装饰分割线 */
.nav-group::after {
  content: '';
  display: block;
  height: 1px;
  margin: 6px auto 2px;
  width: 60%;
  background: linear-gradient(90deg, transparent, rgba(200, 152, 59, 0.12), transparent);
}

.nav-group:last-child::after {
  display: none;
}

/* --- 一级菜单项 --- */
.nav-item {
  display: flex;
  align-items: center;
  padding: 10px 12px;
  min-height: 40px;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
  border-radius: 8px;
  color: #d4c08a;
  font-size: 13px;
  letter-spacing: 0.5px;
  position: relative;
  background: transparent;
  border: 1px solid transparent;
  overflow: hidden;
  -webkit-tap-highlight-color: transparent;
}

/* 左侧激活色条 */
.nav-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 20%;
  height: 60%;
  width: 3px;
  background: #c8983b;
  border-radius: 0 3px 3px 0;
  transform: translateX(-6px);
  opacity: 0;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.nav-item:hover {
  background: rgba(255, 255, 255, 0.06);
  color: #f0d060;
  border-color: rgba(200, 152, 59, 0.12);
}

.nav-item:hover::before {
  transform: translateX(0);
  opacity: 0.6;
}

.nav-item.active {
  background: linear-gradient(90deg, rgba(200, 152, 59, 0.18), rgba(200, 152, 59, 0.04), transparent);
  border-color: rgba(200, 152, 59, 0.35);
  color: #f5d76e;
  font-weight: 700;
  box-shadow: inset 0 0 20px rgba(200, 152, 59, 0.03);
}

.nav-item.active::before {
  transform: translateX(0);
  opacity: 1;
  background: #e6b849;
  box-shadow: 0 0 8px rgba(230, 184, 73, 0.5);
}

/* 导航图标 — 菱形 */
.nav-icon {
  width: 24px;
  height: 24px;
  margin-right: 10px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.3s ease;
}

.nav-icon .dot {
  width: 9px;
  height: 9px;
  background: rgba(255, 255, 255, 0.35);
  transform: rotate(45deg);
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.nav-item:hover .nav-icon {
  transform: scale(1.05);
}

.nav-item:hover .nav-icon .dot {
  background: rgba(240, 208, 96, 0.5);
  border-color: rgba(240, 208, 96, 0.3);
}

.nav-item.active .nav-icon .dot {
  background: #f0d060;
  border-color: transparent;
  box-shadow: 0 0 8px rgba(240, 208, 96, 0.5);
  width: 11px;
  height: 11px;
}

.nav-text {
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* 展开箭头 */
.nav-arrow {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.25s ease, opacity 0.2s ease;
  opacity: 0.5;
}

.nav-item:hover .nav-arrow {
  opacity: 0.8;
}

.nav-item.active .nav-arrow {
  transform: rotate(180deg);
  opacity: 1;
}

.nav-arrow::after {
  content: '';
  width: 0;
  height: 0;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-top: 5px solid currentColor;
}

/* --- 子菜单 --- */
.sub-menu {
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  padding-left: 20px;
  padding-right: 4px;
  margin-top: 0;
  margin-bottom: 0;
  transition: opacity 0.2s ease, margin 0.2s ease;
}

.sub-menu.open {
  max-height: none;
  opacity: 1;
  margin-top: 6px;
  margin-bottom: 4px;
}

.sub-item {
  display: flex;
  align-items: center;
  margin: 3px 0;
  padding: 7px 10px;
  min-height: 34px;
  background: linear-gradient(135deg, rgba(120, 25, 25, 0.7), rgba(100, 18, 18, 0.7));
  border-radius: 8px;
  color: #c9b380;
  font-size: 12px;
  letter-spacing: 0.5px;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  border: 1px solid rgba(200, 152, 59, 0.18);
  position: relative;
  overflow: hidden;
  -webkit-tap-highlight-color: transparent;
}

/* 子项左侧装饰点 */
.sub-item::before {
  content: '';
  width: 5px;
  height: 5px;
  margin-right: 10px;
  border-radius: 50%;
  background: rgba(200, 152, 59, 0.4);
  flex-shrink: 0;
  transition: background 0.2s ease, box-shadow 0.2s ease, width 0.2s ease, height 0.2s ease;
}

.sub-item:hover {
  background: linear-gradient(135deg, rgba(160, 30, 30, 0.8), rgba(130, 22, 22, 0.8));
  color: #f0d060;
  border-color: rgba(200, 152, 59, 0.45);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.25);
}

.sub-item:hover::before {
  background: #e6b849;
  box-shadow: 0 0 6px rgba(230, 184, 73, 0.6);
  width: 6px;
  height: 6px;
}

.sub-item.active {
  background: linear-gradient(135deg, #b83230, #96281b);
  color: #f5d76e;
  font-weight: 600;
  border-color: rgba(200, 152, 59, 0.55);
  box-shadow: 0 0 12px rgba(184, 50, 48, 0.3), inset 0 0 20px rgba(200, 152, 59, 0.04);
  padding-left: 14px;
}

.sub-item.active::before {
  background: #f0d060;
  width: 7px;
  height: 7px;
  box-shadow: 0 0 8px rgba(240, 208, 96, 0.8), 0 0 16px rgba(240, 208, 96, 0.4);
}

/* 暂无视频占位项：灰色、不抢眼、不可点击 */
.sub-item.sub-empty {
  color: #888;
  font-style: italic;
  opacity: 0.6;
  pointer-events: none;
  cursor: default;
}
.sub-item.sub-empty::before {
  background: transparent !important;
  box-shadow: none !important;
}
.sub-item.sub-empty:hover {
  background: transparent !important;
  color: #888 !important;
}

/* --- 分组子菜单（多视频分组展示） --- */
.sub-menu-grouped.open {
  max-height: none;
}

.sub-group {
  margin-bottom: 8px;
}

.sub-group:last-child {
  margin-bottom: 0;
}

.sub-group-plain .sub-group-title {
  color: #f0d060;
  font-weight: normal;
  letter-spacing: normal;
  border-bottom: none;
  margin-bottom: 2px;
}

.sub-group-title {
  color: #e6c565;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 1.5px;
  padding: 4px 0 3px 8px;
  border-bottom: 1px solid rgba(200, 152, 59, 0.2);
  margin-bottom: 5px;
}

/* --- 底部按钮 --- */
.sidebar-bottom {
  flex-shrink: 0;
  padding: 14px 16px 18px;
  border-top: 1px solid rgba(200, 152, 59, 0.18);
  text-align: center;
  background: linear-gradient(0deg, rgba(0, 0, 0, 0.3), transparent);
}

.btn-back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 26px;
  background: linear-gradient(135deg, #e6b849, #c08a2e);
  color: #3d0606;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 3px;
  border-radius: 24px;
  cursor: pointer;
  white-space: nowrap;
  flex-shrink: 0;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid rgba(255, 220, 120, 0.3);
  box-shadow: 0 3px 12px rgba(0, 0, 0, 0.45);
  position: relative;
  overflow: hidden;
}

.btn-back::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.2), transparent 60%);
  opacity: 0;
  transition: opacity 0.3s;
}

.btn-back:hover {
  background: linear-gradient(135deg, #f0d060, #d4a035);
  color: #4a0a0a;
  box-shadow: 0 4px 20px rgba(240, 208, 96, 0.35), 0 0 30px rgba(230, 184, 73, 0.15);
  transform: translateY(-1px);
}

.btn-back:hover::after {
  opacity: 1;
}

.btn-back:active {
  transform: scale(0.97);
  transition: transform 0.1s;
}

.footer-text {
  margin-top: 12px;
  color: rgba(200, 152, 59, 0.45);
  font-size: 12px;
  letter-spacing: 2px;
}

/* =============================================
   右侧主内容区
   ============================================= */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: #0d0505;
  position: relative;
}

/* --- 视频播放区 --- */
.video-player {
  flex: 1;
  position: relative;
  background: #000;
  overflow: hidden;
}

/* --- 真实背景视频 --- */
.bg-video {
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  height: calc(100% - 56px);
  object-fit: cover;
  z-index: 0;
}

/* --- 视频控制条 --- */
.video-controls {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 56px;
  background: linear-gradient(0deg, rgba(0, 0, 0, 0.92), rgba(15, 5, 5, 0.75) 70%, transparent);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  padding: 0 12px;
  gap: 10px;
}

.btn-play {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.2);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.25s ease;
  flex-shrink: 0;
}

.btn-play:hover {
  background: rgba(240, 208, 96, 0.2);
  border-color: rgba(240, 208, 96, 0.4);
  box-shadow: 0 0 14px rgba(240, 208, 96, 0.15);
  transform: scale(1.05);
}

.btn-play:active {
  transform: scale(0.95);
}

.btn-play .play-icon {
  width: 0;
  height: 0;
  border-left: 11px solid rgba(255, 255, 255, 0.9);
  border-top: 7px solid transparent;
  border-bottom: 7px solid transparent;
  margin-left: 2px;
}

.time-display {
  color: rgba(255, 255, 255, 0.6);
  font-size: 14px;
  font-family: 'Consolas', 'Courier New', monospace;
  flex-shrink: 0;
  min-width: 110px;
  text-align: center;
  letter-spacing: 1px;
}

.progress-bar {
  flex: 1;
  height: 5px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
  cursor: pointer;
  position: relative;
  overflow: visible;
}

.progress-bar:hover {
  height: 7px;
  transition: height 0.15s;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #c8983b, #e6b849);
  border-radius: 3px;
  width: 0;
  transition: width 0.1s linear;
  position: relative;
}

.progress-fill::after {
  content: '';
  position: absolute;
  right: -4px;
  top: 50%;
  transform: translateY(-50%);
  width: 10px;
  height: 10px;
  background: #f0d060;
  border-radius: 50%;
  box-shadow: 0 0 6px rgba(240, 208, 96, 0.5);
  opacity: 0;
  transition: opacity 0.2s;
}

.progress-bar:hover .progress-fill::after {
  opacity: 1;
}

/* 视频加载失败覆盖层（仅覆盖视频区，不影响底部 info-bar） */
.video-error-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 60px;       /* 留出底部控件高度 */
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  color: #fff;
  z-index: 5;
  pointer-events: none;
  animation: errFadeIn 0.4s ease;
}
.video-error-overlay .err-icon {
  font-size: 64px;
  color: #ff6b6b;
  text-shadow: 0 2px 12px rgba(255, 107, 107, 0.5);
  margin-bottom: 16px;
}
.video-error-overlay .err-title {
  font-size: 20px;
  font-weight: 600;
  color: #ff6b6b;
  margin-bottom: 12px;
  letter-spacing: 1px;
}
.video-error-overlay .err-file {
  font-size: 14px;
  color: #cbd5e1;
  font-family: 'Consolas', 'Courier New', monospace;
  background: rgba(0, 0, 0, 0.4);
  padding: 6px 14px;
  border-radius: 4px;
  border: 1px solid rgba(255, 107, 107, 0.3);
  margin-bottom: 12px;
  max-width: 80%;
  word-break: break-all;
  text-align: center;
}
.video-error-overlay .err-hint {
  font-size: 13px;
  color: #94a3b8;
}
@keyframes errFadeIn {
  from { opacity: 0; transform: scale(0.95); }
  to   { opacity: 1; transform: scale(1); }
}
.btn-settings,
.btn-fullscreen {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.1);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: rgba(255, 255, 255, 0.45);
  font-size: 15px;
  transition: all 0.25s ease;
}

.btn-settings:hover,
.btn-fullscreen:hover {
  background: rgba(255, 255, 255, 0.18);
  color: rgba(255, 255, 255, 0.85);
  border-color: rgba(255, 255, 255, 0.25);
}

.btn-fullscreen {
  border-radius: 50%;
}

/* --- 底部信息栏 --- */
.info-bar {
  min-height: 72px;
  max-height: 200px;
  overflow-y: auto;
  flex-shrink: 0;
  background: linear-gradient(90deg, rgba(15, 5, 5, 0.96), rgba(25, 10, 10, 0.96), rgba(15, 5, 5, 0.96));
  border-top: 1px solid rgba(200, 152, 59, 0.18);
  display: flex;
  align-items: flex-start;
  padding: 16px 16px;
  gap: 12px;
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
}

.info-bar .icon-circle {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(200, 152, 59, 0.2), rgba(200, 152, 59, 0.08));
  border: 1px solid rgba(200, 152, 59, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-right: 16px;
  flex-shrink: 0;
  font-size: 18px;
  color: #f0d060;
  box-shadow: 0 0 12px rgba(200, 152, 59, 0.1);
}

.info-text {
  color: #bfa870;
  font-size: 13px;
  line-height: 1.7;
  letter-spacing: 1px;
  flex: 1;
  white-space: normal;
  word-break: break-word;
  overflow-wrap: break-word;
}

.info-text .highlight {
  color: #f0d060;
  font-weight: 700;
  text-shadow: 0 0 6px rgba(240, 208, 96, 0.3);
}

/* =============================================
   内容面板（预留多面板切换）
   ============================================= */
.content-panel {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s ease;
}

.content-panel.visible {
  opacity: 1;
  pointer-events: auto;
}

/* 图片展示模式 */
.image-showcase {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #111;
}

.showcase-img {
  max-width: 70%;
  max-height: 70%;
  object-fit: contain;
  border: 3px solid rgba(200, 152, 59, 0.3);
  border-radius: 4px;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.6);
}

/* =============================================
   启动页 Splash Screen
   主题：同心跟党走 智绘民革情 - 长春民革数字党史展馆
   风格：庄重红色基底 + 金色点缀 + 数字粒子动效
   ============================================= */
.splash {
  position: fixed;
  top: 0; right: 0; bottom: 0; left: 0;
  width: auto; height: auto;
  min-width: 100%;
  min-height: 100vh;
  min-height: 100dvh;
  background-color: #8b0f0f;
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1), visibility 0.7s;
}

.splash.hide {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

/* === 背景层 === */
.splash-bg {
  position: absolute; inset: 0;
  width: auto; height: auto;
  min-width: 100%; min-height: 100%;
  background-color: #8b0f0f;
  background-image:
    radial-gradient(ellipse at 50% 25%, #ac1515 0%, #7a0d0d 45%, #4a0505 80%, #1f0101 100%);
}

.splash-bg::after {
  content: '';
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  background-image:
    repeating-linear-gradient(0deg, transparent, transparent 2px, rgba(255,255,255,0.012) 2px, rgba(255,255,255,0.012) 4px),
    radial-gradient(circle at 20% 15%, rgba(200,152,59,0.08), transparent 45%),
    radial-gradient(circle at 80% 75%, rgba(200,152,59,0.05), transparent 40%);
}

/* === Canvas 粒子层 === */
.splash-canvas {
  position: absolute; inset: 0;
  width: 100%; height: 100%;
  z-index: 1;
  pointer-events: none;
}

/* === 主内容层 === */
.splash-content {
  position: relative;
  z-index: 5;
  text-align: center;
  animation: splashContentIn 1s cubic-bezier(0.22, 1, 0.36, 1) both;
}

@keyframes splashContentIn {
  from { opacity: 0; transform: translateY(40px) scale(0.96); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

/* --- 顶部菱形徽标 --- */
.splash-top-ornament {
  margin-bottom: 28px;
  display: flex;
  justify-content: center;
}

.orn-diamond {
  display: inline-block;
  width: 36px; height: 36px;
  background: linear-gradient(135deg, #e74c3c, #c0392b);
  transform: rotate(45deg);
  border: 2px solid rgba(240,208,96,0.6);
  box-shadow:
    0 0 18px rgba(231,76,60,0.5),
    0 0 36px rgba(231,76,60,0.2),
    inset 0 0 8px rgba(255,255,255,0.1);
  animation: diamondPulse 2.4s ease-in-out infinite;
  position: relative;
}

.orn-diamond::after {
  content: '★';
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%) rotate(-45deg);
  color: #f0d060;
  font-size: 14px;
  text-shadow: 0 0 6px rgba(240,208,96,0.6);
}

@keyframes diamondPulse {
  0%, 100% { box-shadow: 0 0 18px rgba(231,76,60,0.5), 0 0 36px rgba(231,76,60,0.2); }
  50%      { box-shadow: 0 0 28px rgba(231,76,60,0.7), 0 0 50px rgba(231,76,60,0.35); }
}

/* --- 标题行 --- */
.splash-title-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  margin-bottom: 6px;
  cursor: pointer;
}

.splash-title-group:nth-child(3) {
  animation: titleLineIn 1s 0.15s cubic-bezier(0.22, 1, 0.36, 1) both;
}

.splash-title {
  font-size: 40px;
  font-weight: 900;
  color: #f0d060;
  letter-spacing: 10px;
  text-shadow:
    0 0 30px rgba(200,152,59,0.5),
    0 0 60px rgba(200,152,59,0.25),
    0 0 100px rgba(200,152,59,0.1),
    0 2px 8px rgba(0,0,0,0.6);
  margin: 0;
  line-height: 1.3;
  position: relative;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

.splash-title:hover {
  color: #ffe58a;
  text-shadow:
    0 0 40px rgba(240,208,96,0.65),
    0 0 80px rgba(240,208,96,0.35),
    0 0 120px rgba(240,208,96,0.15),
    0 2px 8px rgba(0,0,0,0.6);
}

/* 标题金光扫过 */
.splash-title::after {
  content: '';
  position: absolute;
  top: 0; left: -80%;
  width: 50%;
  height: 100%;
  background: linear-gradient(105deg, transparent 0%, rgba(255,240,200,0.15) 45%, rgba(255,240,200,0.35) 50%, rgba(255,240,200,0.15) 55%, transparent 100%);
  animation: titleGlint 3.5s ease-in-out 1.5s infinite;
  pointer-events: none;
}

@keyframes titleGlint {
  0%   { left: -80%; }
  50%  { left: 120%; }
  100% { left: 120%; }
}

/* 括号装饰 */
.title-deco-bracket {
  font-size: 44px;
  font-weight: 300;
  color: rgba(200,152,59,0.45);
  text-shadow: 0 0 12px rgba(200,152,59,0.25);
  transition: color 0.5s;
  line-height: 1;
  padding: 0 6px;
}

.title-deco-bracket:hover {
  color: rgba(200,152,59,0.75);
}

/* --- 分隔装饰线 --- */
.splash-rule {
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 18px 0 14px;
  animation: ruleIn 0.8s 0.3s cubic-bezier(0.22, 1, 0.36, 1) both;
}

.splash-rule::before,
.splash-rule::after {
  content: '';
  flex: 0 0 52px;
  height: 1px;
  background: linear-gradient(90deg, rgba(200,152,59,0.15), rgba(200,152,59,0.6), rgba(200,152,59,0.15));
}

.splash-rule::before { margin-right: 12px; }
.splash-rule::after  { margin-left:  12px; }

.rule-diamond {
  display: inline-block;
  width: 8px; height: 8px;
  background: rgba(240,208,96,0.7);
  transform: rotate(45deg);
  box-shadow: 0 0 8px rgba(240,208,96,0.4);
}

@keyframes ruleIn {
  from { opacity: 0; transform: scaleX(0.3); }
  to   { opacity: 1; transform: scaleX(1); }
}

/* --- 副标题 --- */
.splash-subtitle {
  font-size: 18px;
  font-weight: 500;
  color: rgba(255,255,255,0.65);
  letter-spacing: 6px;
  margin-bottom: 22px;
  animation: fadeInUp 0.8s 0.45s both;
  text-shadow: 0 1px 4px rgba(0,0,0,0.5);
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* --- 五星装饰 --- */
.splash-stars {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 28px;
  animation: starsIn 0.8s 0.6s both;
}

@keyframes starsIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.s-star {
  width: 14px; height: 14px;
  background: #e74c3c;
  clip-path: polygon(50% 0%, 61% 35%, 98% 35%, 68% 57%, 79% 91%, 50% 70%, 21% 91%, 32% 57%, 2% 35%, 39% 35%);
}

.s-star:nth-child(1) { animation: starBreathe 2.4s ease-in-out 0s infinite; }
.s-star:nth-child(2) { animation: starBreathe 2.4s ease-in-out 0.3s infinite; }
.s-star:nth-child(3) { animation: starBreathe 2.4s ease-in-out 0.6s infinite; width: 17px; height: 17px; }
.s-star:nth-child(4) { animation: starBreathe 2.4s ease-in-out 0.9s infinite; }
.s-star:nth-child(5) { animation: starBreathe 2.4s ease-in-out 1.2s infinite; }

@keyframes starBreathe {
  0%, 100% { opacity: 0.55; transform: scale(1); }
  50%      { opacity: 1;    transform: scale(1.13); }
}

/* --- 进入按钮 --- */
.btn-start {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 60px;
  background-color: #b71c1c;
  background-image: linear-gradient(135deg, #b71c1c, #d32f2f, #b71c1c);
  background-size: 200% 200%;
  color: #fff;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 10px;
  border: 2px solid rgba(240,208,96,0.4);
  border-radius: 50px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow:
    0 8px 32px rgba(183,28,28,0.5),
    0 0 0 10px rgba(183,28,28,0.12);
  animation: btnPulse 2s ease-in-out infinite;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

/* 初始进入动画（只播放一次，完成后由 JS 移除类名） */
.btn-start.is-intro {
  animation: btnPulse 2s ease-in-out infinite, btnFadeIn 0.8s 0.75s both;
}

/* 按钮光泽扫过 */
.btn-start::before {
  content: '';
  position: absolute;
  top: 0; left: -100%;
  width: 80%;
  height: 100%;
  background: linear-gradient(105deg, transparent 0%, rgba(255,255,255,0.08) 40%, rgba(255,255,255,0.2) 50%, rgba(255,255,255,0.08) 60%, transparent 100%);
  animation: btnShine 3s ease-in-out 2s infinite;
}

@keyframes btnShine {
  0%   { left: -100%; }
  40%  { left: 120%; }
  100% { left: 120%; }
}

/* 按钮金色边框发光 */
.btn-start::after {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: 54px;
  border: 2px solid transparent;
  background: linear-gradient(135deg, rgba(240,208,96,0), rgba(240,208,96,0.35), rgba(240,208,96,0)) border-box;
  -webkit-mask: linear-gradient(#fff 0 0) padding-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  animation: btnRingPulse 2s ease-in-out infinite;
}

@keyframes btnFadeIn {
  from { opacity: 0; transform: translateY(14px) scale(0.92); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes btnPulse {
  0%, 100% {
    box-shadow: 0 8px 32px rgba(183,28,28,0.5), 0 0 0 10px rgba(183,28,28,0.12);
  }
  50% {
    box-shadow: 0 8px 40px rgba(211,47,47,0.6), 0 0 0 18px rgba(183,28,28,0);
  }
}

@keyframes btnRingPulse {
  0%, 100% { opacity: 0.5; }
  50%      { opacity: 1; }
}

.btn-start:hover {
  background-image: linear-gradient(135deg, #d32f2f, #ef5350, #d32f2f);
  border-color: rgba(240,208,96,0.7);
  transform: translateY(-3px) scale(1.03);
  box-shadow:
    0 12px 44px rgba(211,47,47,0.6),
    0 0 0 14px rgba(211,47,47,0.08);
  animation: none;
}

.btn-start:active {
  transform: scale(0.96);
  transition: transform 0.1s;
}

/* --- 电视大屏适配 --- */
@media (min-width: 1600px) {
  .splash-title {
    font-size: 52px;
    letter-spacing: 14px;
  }
  .title-deco-bracket {
    font-size: 56px;
  }
  .splash-subtitle {
    font-size: 22px;
    letter-spacing: 8px;
  }
  .btn-start {
    padding: 18px 76px;
    font-size: 24px;
    letter-spacing: 14px;
  }
  .splash-top-ornament { margin-bottom: 36px; }
  .orn-diamond { width: 44px; height: 44px; }
  .s-star { width: 16px; height: 16px; }
  .s-star:nth-child(3) { width: 20px; height: 20px; }
  .splash-rule { margin: 24px 0 18px; }
  .splash-rule::before,
  .splash-rule::after { flex: 0 0 80px; }

  /* 电视大屏下侧边栏标题放大 */
  .sidebar {
    width: 260px;
    min-width: 260px;
  }
  .title-line {
    font-size: 24px;
    letter-spacing: 4px;
  }
  .header-subtitle {
    font-size: 15px;
    letter-spacing: 6px;
  }
  .header-emblem-star {
    width: 32px; height: 32px;
    font-size: 16px;
  }
  .star { width: 14px; height: 14px; }
  .star:nth-child(3) { width: 18px; height: 18px; }
}

/* =============================================
   触摸屏 / 电视触摸 交互优化
   ============================================= */

/* 消除默认触摸高亮 */
.nav-item, .sub-item, .btn-start, .btn-back, .btn-play, .btn-settings, .btn-fullscreen, .progress-bar, .splash-title, .splash-title-group {
  -webkit-tap-highlight-color: transparent;
}

/* 按钮触摸反馈（替代 hover，触摸生效） */
.btn-start:active {
  background-image: linear-gradient(135deg, #d32f2f, #ef5350, #d32f2f);
  transform: scale(0.96);
  -webkit-transform: scale(0.96);
}

.btn-back:active {
  background-image: -webkit-linear-gradient(135deg, #f0d060, #d4a035);
  background-image: linear-gradient(135deg, #f0d060, #d4a035);
  transform: scale(0.96);
  -webkit-transform: scale(0.96);
}

.nav-item:active {
  background: rgba(255, 255, 255, 0.08);
}

.sub-item:active {
  background-image: -webkit-linear-gradient(135deg, rgba(160, 30, 30, 0.85), rgba(130, 22, 22, 0.85));
  background-image: linear-gradient(135deg, rgba(160, 30, 30, 0.85), rgba(130, 22, 22, 0.85));
}

.btn-play:active {
  background: rgba(240, 208, 96, 0.25);
  transform: scale(0.92);
  -webkit-transform: scale(0.92);
}

/* 电视触摸屏上用 pointer 事件更精准（同时兼容鼠标和手指） */
.nav-item, .sub-item, .btn-start, .btn-back, .btn-play, .progress-bar, .btn-settings, .btn-fullscreen, .splash-title, .splash-title-group {
  touch-action: manipulation;
  -ms-touch-action: manipulation;
}