/* ============================================================
   DDW 学术站 — 视频合集页样式
   依赖：ddw-main.css（复用其 :root 令牌，本文件不写裸色值）
   ============================================================ */

/* ---------- 合集切换 tab ---------- */
.ddw-col-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  border-bottom: 1px solid var(--ddw-border);
  padding: 0 0 14px;
  margin-bottom: 26px;
  list-style: none;
}

.ddw-col-tabs li {
  margin: 0;
}

.ddw-col-tabs a {
  display: inline-block;
  padding: 9px 20px;
  border: 1px solid var(--ddw-border);
  border-radius: 30px;
  font-size: 14px;
  font-weight: 500;
  color: var(--ddw-muted);
  text-decoration: none;
  background: #fff;
  transition: all .2s;
}

.ddw-col-tabs a:hover {
  border-color: var(--ddw-primary);
  color: var(--ddw-primary);
}

.ddw-col-tabs a.active {
  background: var(--ddw-primary);
  border-color: var(--ddw-primary);
  color: #fff;
}

/* ---------- 播放器 ---------- */
.ddw-player {
  position: relative;
  background: #000;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 6px 20px rgba(14, 77, 140, .14);
}

.ddw-player video {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #000;
}

/* 不支持 aspect-ratio 的旧浏览器兜底 */
@supports not (aspect-ratio: 16 / 9) {
  .ddw-player video {
    height: 0;
    padding-bottom: 56.25%;
  }
}

/* src 缺失 / 加载失败时的占位层 */
.ddw-player-fallback {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, var(--ddw-primary), var(--ddw-primary-dark));
  color: #fff;
  text-align: center;
  padding: 30px;
}

/* 播放器 Loading 缓冲动画层 */
.ddw-player-loading {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, .65);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: #fff;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s ease;
  z-index: 5;
}

.ddw-player.is-loading .ddw-player-loading {
  opacity: 1;
  pointer-events: auto;
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 3px solid rgba(255, 255, 255, .25);
  border-top-color: var(--ddw-gold, #f39c12);
  border-radius: 50%;
  animation: ddwSpin .8s linear infinite;
}

.loading-text {
  font-size: 13px;
  letter-spacing: 1px;
  color: rgba(255, 255, 255, .9);
}

@keyframes ddwSpin {
  to { transform: rotate(360deg); }
}

.ddw-player.is-empty .ddw-player-fallback {
  display: flex;
}

.ddw-player.is-empty video {
  display: none;
}

.ddw-player-fallback .fb-icon {
  font-size: 44px;
  color: var(--ddw-gold);
  margin-bottom: 14px;
}

.ddw-player-fallback .fb-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.ddw-player-fallback .fb-desc {
  font-size: 14px;
  opacity: .85;
  line-height: 1.7;
  max-width: 420px;
}

/* ---------- 当前视频信息 ---------- */
.ddw-now-title {
  font-size: 21px;
  font-weight: 600;
  color: var(--ddw-primary);
  margin: 22px 0 8px;
  line-height: 1.5;
}

.ddw-now-meta {
  font-size: 14px;
  color: var(--ddw-muted);
  margin-bottom: 12px;
}

.ddw-now-meta .sep {
  margin: 0 8px;
  color: var(--ddw-border);
}

.ddw-now-desc {
  font-size: 15px;
  line-height: 2;
  color: var(--ddw-text);
}

/* ---------- 视频列表 ---------- */
.ddw-video-list {
  max-height: 620px;
  overflow-y: auto;
  border: 1px solid var(--ddw-border);
  border-radius: 8px;
  background: #fff;
}

.ddw-video-list-head {
  padding: 13px 16px;
  border-bottom: 1px solid var(--ddw-border);
  background: var(--ddw-bg-light);
  font-size: 14px;
  font-weight: 600;
  color: var(--ddw-primary);
  position: sticky;
  top: 0;
  z-index: 2;
}

.ddw-video-item {
  display: flex;
  gap: 12px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--ddw-border);
  border-left: 3px solid transparent;
  cursor: pointer;
  transition: background .2s;
}

.ddw-video-item:last-child {
  border-bottom: none;
}

.ddw-video-item:hover {
  background: var(--ddw-bg-light);
}

.ddw-video-item.active {
  background: rgba(14, 77, 140, .07);
  border-left-color: var(--ddw-accent);
}

.ddw-video-item .thumb-wrap {
  position: relative;
  flex: 0 0 120px;
  width: 120px;
}

/* 缩略图占位底：品牌渐变 + 播放图标 */
.ddw-video-item .thumb-poster {
  position: relative;
  width: 120px;
  aspect-ratio: 16 / 9;
  border-radius: 4px;
  background: linear-gradient(135deg, var(--ddw-primary), var(--ddw-primary-dark));
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255, 255, 255, .7);
  font-size: 22px;
  overflow: hidden;
}

.ddw-video-item .thumb-poster img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.ddw-video-item .thumb {
  position: relative;
  z-index: 1;
  width: 120px;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 4px;
  background: linear-gradient(135deg, var(--ddw-primary), var(--ddw-primary-dark));
  display: block;
}

.ddw-video-item .v-duration {
  position: absolute;
  right: 4px;
  bottom: 4px;
  background: rgba(0, 0, 0, .78);
  color: #fff;
  font-size: 11px;
  padding: 1px 5px;
  border-radius: 3px;
  line-height: 1.6;
}

.ddw-video-item .v-info {
  flex: 1;
  min-width: 0;
}

.ddw-video-item .v-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--ddw-text);
  line-height: 1.55;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.ddw-video-item.active .v-title {
  color: var(--ddw-primary);
}

.ddw-video-item .v-speaker {
  font-size: 12px;
  color: var(--ddw-muted);
  margin-top: 5px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* 播放中图标 */
.ddw-video-item.active .v-speaker::before {
  content: "\f144";
  font-family: "Font Awesome 5 Free";
  font-weight: 900;
  color: var(--ddw-accent);
  margin-right: 5px;
}

/* ---------- 空态 / 合集不存在 ---------- */
.ddw-video-empty {
  text-align: center;
  padding: 70px 20px;
  background: #fff;
  border: 1px solid var(--ddw-border);
  border-radius: 8px;
}

.ddw-video-empty .em-icon {
  font-size: 46px;
  color: var(--ddw-border);
  margin-bottom: 16px;
}

.ddw-video-empty h3 {
  font-size: 19px;
  color: var(--ddw-primary);
  margin-bottom: 10px;
}

.ddw-video-empty p {
  color: var(--ddw-muted);
  font-size: 14px;
  margin-bottom: 20px;
}

/* ---------- 响应式 ---------- */
@media (max-width: 991px) {
  .ddw-video-list {
    max-height: none;
    margin-top: 28px;
  }
}

@media (max-width: 768px) {
  .ddw-col-tabs {
    gap: 8px;
  }

  .ddw-col-tabs a {
    padding: 8px 16px;
    font-size: 13px;
  }

  .ddw-now-title {
    font-size: 18px;
  }

  .ddw-video-item .thumb-wrap,
  .ddw-video-item .thumb {
    flex-basis: 96px;
    width: 96px;
  }
}