style.css

:root {
  --yt-black: #0f0f0f;
  --yt-surface: #0f0f0f;
  --yt-surface-hover: #272727;
  --yt-card: #272727;
  --yt-card-hover: #3f3f3f;
  --yt-chip-bg: rgba(255, 255, 255, 0.1);
  --yt-chip-hover: rgba(255, 255, 255, 0.2);
  --yt-border: rgba(255, 255, 255, 0.15);
  
  --yt-red: #ff0000;
  --yt-red-hover: #cc0000;
  --yt-white: #f1f1f1;
  --yt-gray: #aaaaaa;
  --yt-dim: #717171;

  --emerald: #10b981;
  --emerald-bg: rgba(16, 185, 129, 0.15);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body.yt-dark {
  background-color: var(--yt-black);
  color: var(--yt-white);
  font-family: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  margin: 0;
  padding: 0;
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.4;
  -webkit-font-smoothing: antialiased;
}

.yt-navbar {
  min-height: 56px;
  background-color: var(--yt-black);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.yt-nav-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.yt-icon-btn {
  background: none;
  border: none;
  color: var(--yt-white);
  cursor: pointer;
  padding: 8px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}

.yt-icon-btn:hover {
  background: var(--yt-surface-hover);
}

.yt-logo-wrap {
  display: flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  user-select: none;
}

.yt-brand-name {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--yt-white);
  font-family: 'Roboto', sans-serif;
  white-space: nowrap;
}

.yt-country-code {
  font-size: 0.65rem;
  color: var(--yt-gray);
  vertical-align: super;
  margin-top: -8px;
  margin-left: 2px;
  font-weight: 500;
}

.yt-nav-center {
  flex: 0 1 640px;
  margin: 0 20px;
}

.yt-search-container {
  display: flex;
  align-items: center;
  width: 100%;
}

.yt-search-box {
  display: flex;
  align-items: center;
  background: #121212;
  border: 1px solid #303030;
  border-radius: 40px 0 0 40px;
  padding: 0 16px;
  height: 40px;
  flex: 1;
  position: relative;
}

.yt-search-box:focus-within {
  border-color: #1c62b9;
}

.yt-search-box input {
  background: transparent;
  border: none;
  color: var(--yt-white);
  font-size: 0.95rem;
  width: 100%;
  outline: none;
  font-family: inherit;
}

.yt-clear-btn {
  background: none;
  border: none;
  color: var(--yt-gray);
  font-size: 1.2rem;
  cursor: pointer;
  padding: 0 4px;
}

.yt-search-submit {
  width: 64px;
  height: 40px;
  background: #222222;
  border: 1px solid #303030;
  border-left: none;
  border-radius: 0 40px 40px 0;
  color: var(--yt-white);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}

.yt-search-submit:hover {
  background: #272727;
}

.yt-nav-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.yt-save-indicator {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  color: var(--emerald);
  background: var(--emerald-bg);
  padding: 4px 10px;
  border-radius: 16px;
  font-weight: 500;
  white-space: nowrap;
}

.save-dot {
  width: 6px;
  height: 6px;
  background: var(--emerald);
  border-radius: 50%;
  animation: yt-pulse 2s infinite ease-in-out;
}

@keyframes yt-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

.yt-progress-pill {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--yt-chip-bg);
  padding: 6px 12px;
  border-radius: 18px;
  font-size: 0.78rem;
  font-weight: 500;
  white-space: nowrap;
}

.progress-pill-bar {
  width: 70px;
  height: 5px;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 999px;
  overflow: hidden;
}

.progress-pill-fill {
  height: 100%;
  background: var(--emerald);
  border-radius: 999px;
  transition: width 0.3s ease;
}

.yt-watch-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 450px;
  gap: 24px;
  max-width: 1750px;
  margin: 0 auto;
  padding: 24px 24px 60px;
}

.yt-primary-col {
  display: flex;
  flex-direction: column;
}

.yt-player-wrapper {
  width: 100%;
  position: relative;
  aspect-ratio: 16 / 9;
  background: #000;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.6);
}

#yt-player-container, #yt-player {
  width: 100%;
  height: 100%;
  border: none;
  display: block;
}

.yt-custom-controls-bar {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.85) 0%, transparent 100%);
  padding: 0 14px 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  opacity: 1;
  transition: opacity 0.25s ease;
  z-index: 10;
}

.yt-player-wrapper.controls-hidden .yt-custom-controls-bar {
  opacity: 0;
  pointer-events: none;
}

.yt-scrubber-wrap {
  width: 100%;
  height: 14px;
  display: flex;
  align-items: center;
  cursor: pointer;
  position: relative;
}

.yt-scrubber-track {
  width: 100%;
  height: 4px;
  background: rgba(255, 255, 255, 0.25);
  position: relative;
  border-radius: 2px;
  transition: height 0.1s ease;
}

.yt-scrubber-wrap:hover .yt-scrubber-track {
  height: 6px;
}

.yt-scrubber-loaded {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  background: rgba(255, 255, 255, 0.4);
  border-radius: 2px;
}

.yt-scrubber-played {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  background: var(--yt-red);
  border-radius: 2px;
}

.yt-scrubber-thumb {
  position: absolute;
  right: -6px;
  top: 50%;
  transform: translateY(-50%) scale(0);
  width: 13px;
  height: 13px;
  background: var(--yt-red);
  border-radius: 50%;
  transition: transform 0.1s ease;
}

.yt-scrubber-wrap:hover .yt-scrubber-thumb {
  transform: translateY(-50%) scale(1);
}

.yt-controls-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--yt-white);
}

.yt-controls-left, .yt-controls-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.yt-ctrl-btn {
  background: none;
  border: none;
  color: var(--yt-white);
  cursor: pointer;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: transform 0.1s;
}

.yt-ctrl-btn:hover {
  transform: scale(1.1);
}

.yt-time-display {
  font-size: 0.82rem;
  color: #ddd;
  font-family: inherit;
  margin-left: 6px;
  user-select: none;
}

.yt-video-title {
  font-size: 1.3rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--yt-white);
  margin-top: 14px;
  margin-bottom: 10px;
}

.yt-owner-actions-row {
  display: flex;
  justify-content: flex-start;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 14px;
}

.yt-action-buttons {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.yt-pill-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--yt-chip-bg);
  color: var(--yt-white);
  border: none;
  height: 36px;
  padding: 0 16px;
  border-radius: 18px;
  font-size: 0.88rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
  text-decoration: none;
  font-family: inherit;
  white-space: nowrap;
}

.yt-pill-btn:hover:not(:disabled) {
  background: var(--yt-chip-hover);
}

.yt-pill-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.yt-pill-btn-primary {
  background: #272727;
}

.yt-pill-btn.btn-watched-active {
  background: var(--emerald-bg) !important;
  color: var(--emerald) !important;
}

.yt-auto-next-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  user-select: none;
  margin-left: 4px;
}

.yt-auto-next-toggle input {
  display: none;
}

.yt-toggle-pill {
  width: 32px;
  height: 18px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 999px;
  position: relative;
  transition: background 0.2s;
}

.yt-toggle-pill::after {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 14px;
  height: 14px;
  background: #fff;
  border-radius: 50%;
  transition: transform 0.2s;
}

.yt-auto-next-toggle input:checked + .yt-toggle-pill {
  background: #3ea6ff;
}

.yt-auto-next-toggle input:checked + .yt-toggle-pill::after {
  transform: translateX(14px);
}

.yt-toggle-label {
  font-size: 0.78rem;
  color: var(--yt-gray);
  font-weight: 500;
}

.yt-description-box {
  background: var(--yt-surface-hover);
  border-radius: 12px;
  padding: 14px 16px;
  margin-top: 4px;
  cursor: pointer;
  transition: background 0.2s;
}

.yt-description-box:hover {
  background: #333333;
}

.yt-desc-header {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--yt-white);
  margin-bottom: 6px;
}

.yt-desc-dot {
  color: var(--yt-dim);
}

.yt-desc-chapter {
  color: #3ea6ff;
}

.yt-desc-text {
  font-size: 0.88rem;
  line-height: 1.5;
  color: #e5e5e5;
}

.yt-shortcuts-box {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 14px;
  padding: 10px 14px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 8px;
  font-size: 0.78rem;
  color: var(--yt-gray);
  flex-wrap: wrap;
}

.shortcuts-title {
  font-weight: 600;
}

.shortcuts-keys {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

kbd {
  background: #222;
  border: 1px solid #444;
  color: var(--yt-white);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  padding: 2px 6px;
  border-radius: 4px;
}

.yt-secondary-col {
  display: flex;
  flex-direction: column;
}

.yt-playlist-panel {
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 12px;
  background: #0f0f0f;
  display: flex;
  flex-direction: column;
  height: calc(100vh - 90px);
  max-height: 880px;
  position: sticky;
  top: 72px;
  overflow: hidden;
}

.yt-playlist-header {
  padding: 14px 16px 10px;
  background: #1f1f1f;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  flex-direction: column;
  gap: 10px;
  flex-shrink: 0;
}

.yt-playlist-title-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.yt-playlist-title {
  display: flex;
  align-items: center;
  gap: 8px;
}

.yt-playlist-title h2 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--yt-white);
}

.yt-count-badge {
  font-size: 0.75rem;
  color: var(--yt-gray);
  background: rgba(255, 255, 255, 0.1);
  padding: 2px 8px;
  border-radius: 10px;
}

.yt-accordion-quick-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.yt-text-btn {
  background: none;
  border: none;
  color: var(--yt-gray);
  font-size: 0.76rem;
  cursor: pointer;
  transition: color 0.2s;
}

.yt-text-btn:hover {
  color: var(--yt-white);
}

.yt-dot-divider {
  color: var(--yt-dim);
  font-size: 0.7rem;
}

.yt-filter-chips {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 2px;
}

.yt-chip {
  background: var(--yt-chip-bg);
  border: none;
  color: var(--yt-white);
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.2s;
}

.yt-chip:hover {
  background: var(--yt-chip-hover);
}

.yt-chip.active {
  background: #ffffff;
  color: #0f0f0f;
  font-weight: 600;
}

.yt-playlist-scroll {
  overflow-y: auto;
  overflow-x: hidden;
  overscroll-behavior: contain;
  flex: 1;
  min-height: 0;
  display: flex;
  flex-direction: column;
}

.yt-playlist-scroll::-webkit-scrollbar {
  width: 8px;
}

.yt-playlist-scroll::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.2);
  border-radius: 4px;
}

.yt-playlist-scroll::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.35);
}

.chapter-item {
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  flex-shrink: 0;
}

.chapter-header {
  padding: 10px 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  user-select: none;
  background: rgba(255, 255, 255, 0.02);
  transition: background 0.2s;
  min-height: 48px;
}

.chapter-header:hover {
  background: rgba(255, 255, 255, 0.06);
}

.chapter-header-left {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1;
  min-width: 0;
}

.chapter-title-text {
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--yt-white);
  line-height: 1.3;
}

.chapter-progress-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.chapter-mini-bar {
  width: 50px;
  height: 3px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 2px;
  overflow: hidden;
}

.chapter-mini-bar-fill {
  height: 100%;
  background: var(--emerald);
  border-radius: 2px;
  transition: width 0.3s;
}

.chapter-desc-text {
  font-size: 0.72rem;
  color: var(--yt-gray);
}

.chapter-header-right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.chapter-badge-count {
  font-size: 0.72rem;
  font-family: 'JetBrains Mono', monospace;
  color: var(--yt-gray);
}

.chapter-chevron {
  color: var(--yt-gray);
  transition: transform 0.2s ease;
  display: flex;
}

.chapter-item.expanded .chapter-chevron {
  transform: rotate(180deg);
}

.video-list {
  display: none;
  flex-direction: column;
  background: rgba(0, 0, 0, 0.25);
  flex-shrink: 0;
}

.chapter-item.expanded .video-list {
  display: flex;
}

.video-row {
  display: flex;
  align-items: center;
  padding: 8px 12px;
  gap: 10px;
  cursor: pointer;
  transition: background 0.15s;
  flex-shrink: 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
}

.video-row:hover {
  background: var(--yt-surface-hover);
}

.video-row.current-playing {
  background: rgba(255, 255, 255, 0.1);
  border-left: 3px solid var(--yt-red);
}

.check-watched-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--yt-dim);
  padding: 2px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: color 0.15s, transform 0.1s;
}

.check-watched-btn:hover {
  color: var(--emerald);
  transform: scale(1.15);
}

.video-row.is-watched .check-watched-btn {
  color: var(--emerald);
}

@keyframes checkmarkPop {
  0% {
    transform: scale(0.5);
    opacity: 0.3;
  }
  60% {
    transform: scale(1.25);
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}

.video-row.is-watched .check-watched-btn svg {
  animation: checkmarkPop 0.28s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.video-thumb-container {
  width: 140px;
  height: 78px;
  border-radius: 8px;
  background-size: cover;
  background-position: center;
  background-color: #000;
  flex-shrink: 0;
  position: relative;
  overflow: hidden;
}

.video-time-badge {
  position: absolute;
  bottom: 4px;
  right: 4px;
  background: rgba(0, 0, 0, 0.8);
  color: #fff;
  font-size: 0.68rem;
  font-weight: 600;
  padding: 1px 4px;
  border-radius: 4px;
  font-family: 'JetBrains Mono', monospace;
}

.video-meta-col {
  display: flex;
  flex-direction: column;
  gap: 3px;
  flex: 1;
  min-width: 0;
}

.video-meta-title {
  font-size: 0.86rem;
  font-weight: 500;
  color: var(--yt-white);
  line-height: 1.35;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-row.current-playing .video-meta-title {
  color: #fff;
  font-weight: 700;
}

.video-row.is-watched:not(.current-playing) .video-meta-title {
  color: var(--yt-gray);
}

.video-meta-channel {
  font-size: 0.74rem;
  color: var(--yt-gray);
}

.video-meta-extra {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.7rem;
  color: var(--yt-dim);
}

.playing-badge {
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--yt-red);
  background: rgba(255, 0, 0, 0.15);
  border: 1px solid rgba(255, 0, 0, 0.3);
  padding: 1px 6px;
  border-radius: 4px;
  width: fit-content;
}

.empty-search-state {
  padding: 30px 16px;
  text-align: center;
  color: var(--yt-gray);
  font-size: 0.88rem;
}

.app-footer {
  text-align: center;
  font-size: 0.78rem;
  color: var(--yt-dim);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 16px 0;
  margin-top: 40px;
}

.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: #212121;
  color: var(--yt-white);
  padding: 10px 18px;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8);
  font-size: 0.84rem;
  font-weight: 500;
  z-index: 99999;
  transform: translateY(80px);
  opacity: 0;
  transition: all 0.25s ease;
  pointer-events: none;
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

.hidden {
  display: none !important;
}

@media (max-width: 1150px) {
  .yt-watch-layout {
    grid-template-columns: 1fr;
    padding: 16px;
  }

  .yt-playlist-panel {
    position: static;
    height: auto;
    max-height: 700px;
  }
}

@media (max-width: 768px) {
  .yt-navbar {
    padding: 0 10px;
  }

  .yt-nav-center {
    display: none;
  }

  .yt-watch-layout {
    padding: 10px 10px 40px;
    gap: 16px;
  }

  .yt-owner-actions-row {
    flex-direction: column;
    align-items: stretch;
  }

  .yt-action-buttons {
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .yt-shortcuts-box {
    display: none;
  }
}

@media (max-width: 480px) {
  .yt-save-indicator {
    display: none;
  }

  .yt-nav-right {
    gap: 6px;
  }

  .yt-progress-pill {
    padding: 4px 8px;
    font-size: 0.68rem;
  }

  .progress-pill-bar {
    width: 40px;
  }

  .yt-brand-name {
    font-size: 1rem;
  }
}