/* ==========================================================================
   课程中心 · 列表页（深色科技风）
   ========================================================================== */
.cc-page {
  background: #0a0e1a;
  color: #e6edf5;
  min-height: 100vh;
  padding-top: 72px; /* 固定导航栏高度 */
}

.cc-container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Hero ---------- */
.cc-hero {
  position: relative;
  overflow: hidden;
  padding: 72px 24px 64px;
  background:
    radial-gradient(1200px 400px at 80% -10%, rgba(0, 184, 212, 0.16), transparent 60%),
    radial-gradient(900px 360px at 10% 110%, rgba(0, 120, 255, 0.14), transparent 60%),
    linear-gradient(180deg, #0d1424 0%, #0a0e1a 100%);
  border-bottom: 1px solid rgba(0, 212, 255, 0.12);
}

.cc-hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.35;
  pointer-events: none;
}
.cc-hero-glow--1 {
  width: 380px; height: 380px;
  background: #00b8d4;
  top: -160px; right: 8%;
}
.cc-hero-glow--2 {
  width: 300px; height: 300px;
  background: #1e6bff;
  bottom: -180px; left: 6%;
  opacity: 0.25;
}

.cc-hero-inner {
  position: relative;
  max-width: 1240px;
  margin: 0 auto;
  text-align: center;
}
.cc-hero-en {
  font-size: 13px;
  letter-spacing: 6px;
  color: #00d4ff;
  font-weight: 600;
  margin-bottom: 14px;
}
.cc-hero-title {
  font-size: 44px;
  font-weight: 700;
  letter-spacing: 4px;
  margin: 0 0 16px;
  background: linear-gradient(90deg, #ffffff 20%, #7fe7ff 70%, #00d4ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.cc-hero-desc {
  font-size: 16px;
  color: #9fb2c8;
  margin: 0;
  letter-spacing: 1px;
}

/* ---------- 筛选栏 ---------- */
.cc-filter-bar {
  position: sticky;
  top: 64px;
  z-index: 50;
  background: rgba(10, 14, 26, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.cc-filter-bar .cc-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 16px;
  padding-bottom: 16px;
  flex-wrap: wrap;
}
.cc-tabs {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.cc-tab {
  display: inline-block;
  padding: 8px 20px;
  border-radius: 999px;
  font-size: 14px;
  color: #9fb2c8;
  text-decoration: none;
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: rgba(255, 255, 255, 0.03);
  transition: all 0.2s ease;
  cursor: pointer;
  user-select: none;
}
.cc-tab:hover {
  color: #dff7ff;
  border-color: rgba(0, 212, 255, 0.4);
}
.cc-tab.is-active {
  color: #04121a;
  font-weight: 600;
  background: linear-gradient(135deg, #00d4ff, #00b8d4);
  border-color: transparent;
  box-shadow: 0 4px 16px rgba(0, 184, 212, 0.35);
}

.cc-sort { display: flex; gap: 4px; }
.cc-sort-btn {
  background: none;
  border: none;
  color: #7d90a8;
  font-size: 13px;
  padding: 6px 14px;
  cursor: pointer;
  border-radius: 6px;
  transition: color 0.2s;
}
.cc-sort-btn:hover { color: #cfe4f5; }
.cc-sort-btn.is-active {
  color: #00d4ff;
  font-weight: 600;
  position: relative;
}
.cc-sort-btn.is-active::after {
  content: '';
  position: absolute;
  left: 14px; right: 14px; bottom: 0;
  height: 2px;
  background: #00d4ff;
  border-radius: 2px;
}

/* ---------- 网格 ---------- */
.cc-main { padding: 40px 0 72px; }
.cc-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.cc-card {
  display: block;
  background: #111827;
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 14px;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}
.cc-card:hover {
  transform: translateY(-6px);
  border-color: rgba(0, 212, 255, 0.45);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.45), 0 0 0 1px rgba(0, 212, 255, 0.15);
}

.cc-card-cover {
  position: relative;
  aspect-ratio: 16 / 9;
  background: #0c1322;
  overflow: hidden;
}
.cc-card-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}
.cc-card:hover .cc-card-cover img { transform: scale(1.05); }

.cc-card-cover-empty {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(0, 212, 255, 0.35);
  background: linear-gradient(135deg, #0e1a2e, #0a1322);
}
.cc-card-cover-empty svg { width: 56px; height: 56px; }

.cc-card-tag {
  position: absolute;
  top: 12px;
  left: 12px;
  padding: 4px 12px;
  font-size: 12px;
  color: #dff7ff;
  background: rgba(0, 20, 30, 0.65);
  border: 1px solid rgba(0, 212, 255, 0.4);
  border-radius: 999px;
  backdrop-filter: blur(4px);
}

.cc-card-play {
  position: absolute;
  top: 50%; left: 50%;
  width: 58px; height: 58px;
  margin: -29px 0 0 -29px;
  border-radius: 50%;
  background: rgba(0, 20, 30, 0.6);
  border: 1.5px solid rgba(0, 212, 255, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: scale(0.85);
  transition: all 0.25s ease;
  backdrop-filter: blur(4px);
}
.cc-card-play svg { width: 22px; height: 22px; color: #00d4ff; margin-left: 3px; }
.cc-card:hover .cc-card-play { opacity: 1; transform: scale(1); }

.cc-card-body { padding: 18px 20px 20px; }
.cc-card-title {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 600;
  color: #f0f6fc;
  line-height: 1.45;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  min-height: 2.9em;
}
.cc-card-summary {
  margin: 0 0 14px;
  font-size: 13px;
  color: #8ea0b6;
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  min-height: 2.6em;
}
.cc-card-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: #6d809a;
}
.cc-dot { color: #3a4c64; }

/* 骨架卡片（加载中） */
.cc-skeleton {
  background: #111827;
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 14px;
  overflow: hidden;
}
.cc-skeleton .sk-cover {
  aspect-ratio: 16/9;
  background: linear-gradient(90deg, #131c2e 25%, #1a2540 37%, #131c2e 63%);
  background-size: 400% 100%;
  animation: ccShimmer 1.4s ease infinite;
}
.cc-skeleton .sk-line {
  height: 14px;
  margin: 14px 20px 0;
  border-radius: 4px;
  background: linear-gradient(90deg, #131c2e 25%, #1a2540 37%, #131c2e 63%);
  background-size: 400% 100%;
  animation: ccShimmer 1.4s ease infinite;
}
.cc-skeleton .sk-line.short { width: 50%; margin-bottom: 20px; }
@keyframes ccShimmer {
  0% { background-position: 100% 0; }
  100% { background-position: -100% 0; }
}

/* ---------- 空状态 ---------- */
.cc-empty {
  text-align: center;
  padding: 90px 0;
  color: #5c7089;
}
.cc-empty svg { width: 64px; height: 64px; margin-bottom: 18px; opacity: 0.5; }
.cc-empty p { margin: 0; font-size: 15px; }

/* ---------- 分页 ---------- */
.cc-pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  margin-top: 48px;
  flex-wrap: wrap;
}
.cc-page-btn {
  min-width: 40px;
  height: 40px;
  padding: 0 14px;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: rgba(255, 255, 255, 0.03);
  color: #9fb2c8;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
}
.cc-page-btn:hover:not(:disabled):not(.is-active) {
  border-color: rgba(0, 212, 255, 0.5);
  color: #dff7ff;
}
.cc-page-btn.is-active {
  background: linear-gradient(135deg, #00d4ff, #00b8d4);
  border-color: transparent;
  color: #04121a;
  font-weight: 600;
}
.cc-page-btn:disabled { opacity: 0.35; cursor: not-allowed; }
.cc-page-ellipsis {
  color: #55677e;
  padding: 0 4px;
}

/* ==========================================================================
   课程中心 · 播放页
   ========================================================================== */
.cd-page { padding-top: 84px; padding-bottom: 72px; }

/* 面包屑 */
.cd-crumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: #7d90a8;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.cd-crumb a { color: #00d4ff; text-decoration: none; }
.cd-crumb a:hover { text-decoration: underline; }
.cd-crumb-current { color: #9fb2c8; max-width: 60%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* 布局 */
.cd-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 372px;
  gap: 26px;
  align-items: start;
}

/* 播放器 */
.cd-player-col { min-width: 0; }
.cd-player-wrap {
  position: relative;
  aspect-ratio: 16 / 9;
  background: #000;
  border-radius: 14px;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 0 18px 48px rgba(0, 0, 0, 0.5);
}
.cd-player {
  width: 100%;
  height: 100%;
  display: block;
  background: #000;
}
.cd-no-lesson {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: #7d90a8;
  font-size: 15px;
  background: linear-gradient(135deg, #0e1a2e, #0a1322);
}

/* 遮罩 */
.cd-mask {
  position: absolute;
  inset: 0;
  z-index: 5;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 24px;
  background: rgba(6, 10, 20, 0.78);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  transition: opacity 0.25s ease;
}
.cd-mask.is-hidden {
  opacity: 0;
  pointer-events: none;
}
.cd-mask-icon {
  width: 72px; height: 72px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: #00d4ff;
  background: rgba(0, 212, 255, 0.08);
  border: 1.5px solid rgba(0, 212, 255, 0.4);
}
.cd-mask-icon svg { width: 34px; height: 34px; }
.cd-mask h3 {
  margin: 0 0 10px;
  font-size: 20px;
  color: #f0f6fc;
  font-weight: 600;
}
.cd-mask p {
  margin: 0 0 26px;
  font-size: 14px;
  color: #9fb2c8;
  max-width: 380px;
  line-height: 1.7;
}
.cd-mask-btn {
  padding: 12px 40px;
  border: none;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  color: #04121a;
  cursor: pointer;
  background: linear-gradient(135deg, #00d4ff, #00b8d4);
  box-shadow: 0 8px 24px rgba(0, 184, 212, 0.4);
  transition: transform 0.2s, box-shadow 0.2s;
}
.cd-mask-btn:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(0, 184, 212, 0.55); }

/* 当前集 */
.cd-now {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-top: 18px;
  flex-wrap: wrap;
}
.cd-now-ep {
  flex-shrink: 0;
  font-size: 13px;
  font-weight: 600;
  color: #04121a;
  background: linear-gradient(135deg, #00d4ff, #00b8d4);
  padding: 4px 12px;
  border-radius: 6px;
}
.cd-now-title {
  margin: 0;
  font-size: 19px;
  font-weight: 600;
  color: #f0f6fc;
  line-height: 1.5;
}

/* 右侧信息 */
.cd-side {
  background: #111827;
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: 14px;
  overflow: hidden;
}
.cd-info { padding: 22px 22px 18px; border-bottom: 1px solid rgba(255, 255, 255, 0.06); }
.cd-info-tag { position: static; display: inline-block; margin-bottom: 12px; }
.cd-info-title {
  margin: 0 0 12px;
  font-size: 20px;
  font-weight: 700;
  color: #f0f6fc;
  line-height: 1.45;
}
.cd-info-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 12px;
  color: #6d809a;
  margin-bottom: 14px;
}
.cd-info-summary { position: relative; font-size: 13px; color: #9fb2c8; line-height: 1.75; }
.cd-info-summary p { margin: 0; }
.cd-info-summary.is-collapsed #cdSummaryText {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.cd-summary-more {
  display: none;
  background: none;
  border: none;
  color: #00d4ff;
  font-size: 13px;
  cursor: pointer;
  padding: 6px 0 0;
}
.cd-info-summary.is-collapsed .cd-summary-more { display: inline-block; }

/* 集列表 */
.cd-lessons-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 22px;
  font-size: 14px;
  font-weight: 600;
  color: #c8d6e6;
  background: rgba(255, 255, 255, 0.02);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.cd-lessons-count { font-size: 12px; color: #6d809a; font-weight: 400; }
.cd-lessons {
  list-style: none;
  margin: 0;
  padding: 6px;
  max-height: 560px;
  overflow-y: auto;
}
.cd-lessons::-webkit-scrollbar { width: 6px; }
.cd-lessons::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.12); border-radius: 3px; }

.cd-lesson {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.15s;
}
.cd-lesson:hover { background: rgba(0, 212, 255, 0.07); }
.cd-lesson.is-current {
  background: rgba(0, 212, 255, 0.12);
  box-shadow: inset 3px 0 0 #00d4ff;
}
.cd-lesson-no {
  flex-shrink: 0;
  font-size: 12px;
  color: #00d4ff;
  background: rgba(0, 212, 255, 0.1);
  padding: 3px 9px;
  border-radius: 6px;
  white-space: nowrap;
}
.cd-lesson.is-current .cd-lesson-no {
  color: #04121a;
  background: #00d4ff;
  font-weight: 600;
}
.cd-lesson-title {
  flex: 1;
  min-width: 0;
  font-size: 14px;
  color: #c8d6e6;
  line-height: 1.4;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.cd-lesson.is-current .cd-lesson-title { color: #fff; font-weight: 600; }
.cd-lesson-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}
.cd-lesson-dur { font-style: normal; font-size: 12px; color: #6d809a; }
.cd-lesson-done {
  display: none;
  font-style: normal;
  width: 20px; height: 20px;
  line-height: 20px;
  text-align: center;
  font-size: 12px;
  font-weight: 700;
  color: #04121a;
  background: #2ee6a8;
  border-radius: 50%;
}
.cd-lesson.is-done .cd-lesson-done { display: inline-block; }

/* 播放页响应式 */
@media (max-width: 1024px) {
  .cd-layout { grid-template-columns: 1fr; }
  .cd-lessons { max-height: 420px; }
}
@media (max-width: 640px) {
  .cd-page { padding-top: 72px; }
  .cd-container { padding: 0 16px; }
  .cd-mask h3 { font-size: 17px; }
  .cd-mask p { font-size: 13px; }
  .cd-now-title { font-size: 16px; }
  .cd-info-title { font-size: 18px; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .cc-grid { grid-template-columns: repeat(2, 1fr); gap: 20px; }
}
@media (max-width: 640px) {
  .cc-page { padding-top: 60px; }
  .cc-hero { padding: 48px 20px 40px; }
  .cc-hero-title { font-size: 30px; letter-spacing: 2px; }
  .cc-hero-desc { font-size: 14px; }
  .cc-container { padding: 0 16px; }
  .cc-grid { grid-template-columns: 1fr; gap: 18px; }
  .cc-filter-bar { top: 56px; }
  .cc-filter-bar .cc-container { flex-direction: column; align-items: stretch; }
  .cc-sort { align-self: flex-end; }
}