.coach-dock {
  position: absolute;
  left: 10px;
  right: 10px;
  z-index: 12;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 10px 12px 8px;
  border-radius: 16px;
  background: rgba(8, 12, 20, 0.82);
  color: #f8fafc;
  backdrop-filter: blur(10px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.28);
  pointer-events: auto;
}

.player > .coach-dock { bottom: 48px; }
.video-wrapper > .coach-dock { bottom: 8px; }

.coach-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
}

.coach-toggle,
.coach-action,
.coach-panel button,
.coach-word {
  font: inherit;
  cursor: pointer;
}

.coach-toggle {
  flex: 0 0 auto;
  border: 0;
  border-radius: 999px;
  padding: 5px 12px;
  background: linear-gradient(135deg, #0d9488, #2dd4bf);
  color: #fff;
  font-size: 13px;
  font-weight: 800;
}

.coach-dock[data-open="true"] .coach-toggle {
  background: #f0fdfa;
  color: #0f766e;
}

.coach-status {
  margin: 0;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: rgba(248, 250, 252, 0.78);
  font-size: 12px;
}

.coach-rows[hidden],
.coach-actions[hidden],
.coach-panel[hidden] {
  display: none !important;
}

.coach-rows {
  display: grid;
  grid-template-rows: 1.35em 1.7em 1.35em;
  gap: 2px;
  overflow: hidden;
}

.coach-dock[data-roll="forward"] .coach-rows,
.coach-dock[data-roll="back"] .coach-rows {
  animation: coach-roll 280ms ease;
}

@keyframes coach-roll {
  from { transform: translateY(28%); opacity: 0.55; }
  to { transform: translateY(0); opacity: 1; }
}

.coach-row {
  margin: 0;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  color: rgba(248, 250, 252, 0.62);
  font-size: 13px;
  line-height: 1.35;
}

.coach-row.is-current {
  color: #fff;
  font-size: 16px;
  font-weight: 700;
  white-space: normal;
  line-height: 1.45;
}

.coach-row.is-marked { text-decoration: underline; text-decoration-color: #2dd4bf; text-underline-offset: 3px; }

.coach-word {
  border: 0;
  padding: 0 1px;
  background: transparent;
  color: inherit;
  border-radius: 4px;
}

.coach-word.is-marked { box-shadow: inset 0 -2px 0 #2dd4bf; }
.coach-word.is-selected { background: rgba(45, 212, 191, 0.28); }

.coach-actions {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 2px;
}

.coach-action {
  flex: 0 0 auto;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 999px;
  padding: 4px 10px;
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
}

.coach-action.is-on,
.coach-action:hover { background: rgba(45, 212, 191, 0.22); color: #ecfdf5; }

.coach-panel {
  max-height: 34%;
  overflow: auto;
  padding: 8px 10px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.08);
  font-size: 13px;
  line-height: 1.55;
}

.coach-panel[hidden] { display: none; }
.coach-panel p { margin: 0 0 6px; white-space: pre-wrap; }
.coach-panel textarea {
  width: 100%;
  min-height: 68px;
  box-sizing: border-box;
  border: 0;
  border-radius: 8px;
  padding: 8px;
  resize: vertical;
  font: inherit;
}
.coach-panel button,
.coach-panel a {
  display: inline-flex;
  margin-top: 6px;
  margin-right: 8px;
  border-radius: 999px;
  padding: 4px 10px;
  background: linear-gradient(135deg, #0d9488, #2dd4bf);
  color: #fff;
  font-size: 12px;
  font-weight: 800;
  text-decoration: none;
}
.coach-panel button { border: 0; }

.coach-phon { color: #5eead4; }

.seg-tools {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 0.75rem;
}

.seg-tool,
.study-tabs button,
.study-add,
.study-x {
  font: inherit;
  cursor: pointer;
}

.seg-tool {
  border: 0;
  background: transparent;
  color: #64748b;
  font-size: 13px;
  font-weight: 650;
  padding: 0 2px;
}

.seg-tool:hover { color: #0f766e; }

.transcript .seg.is-lined .text {
  text-decoration: underline;
  text-decoration-color: #0f766e;
  text-decoration-thickness: 1.5px;
  text-underline-offset: 4px;
}

#coach-study:empty { display: none; }

#coach-study {
  position: fixed;
  inset: 0;
  z-index: 80;
  pointer-events: none;
}

.study-backdrop {
  position: absolute;
  inset: 0;
  border: 0;
  background: rgba(15, 23, 42, 0.28);
  pointer-events: auto;
  cursor: pointer;
}

.study-pop,
.study-modal {
  pointer-events: auto;
  box-sizing: border-box;
  background: #fff;
  color: #0f172a;
  border: 1px solid #e7e9ef;
  box-shadow: 0 16px 48px rgba(15, 23, 42, 0.12);
}

.study-pop {
  position: fixed;
  overflow: auto;
  border-radius: 18px;
  padding: 14px 14px 12px;
}

.seg-note,
#caption-note {
  display: block;
  width: 100%;
  margin: 0.55rem 0 0;
  padding: 0.45rem 0.7rem;
  border: 0;
  border-radius: 12px;
  background: #f0fdfa;
  color: #0f766e;
  font: inherit;
  font-size: 0.92rem;
  font-weight: 650;
  line-height: 1.5;
  text-align: left;
  cursor: pointer;
}

.seg-note::before,
#caption-note::before {
  content: '笔记  ';
  font-weight: 800;
}

#caption-note {
  grid-column: 1 / -1;
  margin: 8px 0 0;
}

.study-modal {
  position: fixed;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: min(440px, calc(100vw - 32px));
  max-height: min(78vh, 720px);
  display: flex;
  flex-direction: column;
  border-radius: 24px;
  padding: 16px 16px 18px;
}

.study-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}

.study-head strong {
  flex: 1 1 auto;
  min-width: 0;
  font-size: 16px;
  font-weight: 750;
}

.study-head .study-save { margin-top: 0; flex: 0 0 auto; }

.study-x {
  width: 28px;
  height: 28px;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: #64748b;
  font-size: 20px;
  line-height: 1;
}

.study-sentence {
  margin: 0 0 8px;
  color: #0f766e;
  font-size: 14px;
  font-weight: 750;
  line-height: 1.5;
}

.study-save {
  display: inline-flex;
  margin-top: 10px;
  border: 0;
  border-radius: 999px;
  padding: 8px 16px;
  background: linear-gradient(135deg, #0d9488, #2dd4bf);
  color: #fff;
  font: inherit;
  font-size: 13px;
  font-weight: 800;
  cursor: pointer;
}

.study-note textarea {
  width: 100%;
  min-height: 96px;
  box-sizing: border-box;
  border: 1px solid #e7e9ef;
  border-radius: 14px;
  padding: 10px 12px;
  resize: vertical;
  font: inherit;
  color: #0f172a;
  background: #f8fafc;
}

.study-hint,
.study-label {
  margin: 8px 0 0;
  color: #64748b;
  font-size: 12px;
  line-height: 1.5;
}

.study-copy {
  margin: 4px 0 0;
  color: #0f172a;
  font-size: 15px;
  line-height: 1.65;
}

.study-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  margin-bottom: 12px;
  padding: 4px;
  border-radius: 999px;
  background: #f8fafc;
}

.study-tabs button {
  border: 0;
  border-radius: 999px;
  padding: 8px 6px;
  background: transparent;
  color: #64748b;
  font-size: 13px;
  font-weight: 700;
}

.study-tabs button.is-on {
  background: linear-gradient(135deg, #0d9488, #2dd4bf);
  color: #fff;
}

.study-body { overflow: auto; min-height: 0; }

.study-block,
.study-word {
  margin-top: 12px;
  padding: 12px;
  border: 1px solid #e7e9ef;
  border-radius: 16px;
  background: #f0fdfa;
}

.study-badge {
  display: inline-flex;
  margin: 0 0 6px;
  padding: 2px 8px;
  border-radius: 999px;
  background: #ccfbf1;
  color: #0f766e;
  font-size: 12px;
  font-weight: 750;
}

.study-trunk {
  margin: 0;
  font-size: 18px;
  font-weight: 750;
  line-height: 1.45;
}

.study-parts,
.study-points {
  margin: 0;
  padding-left: 1.1rem;
  color: #0f172a;
  font-size: 14px;
  line-height: 1.6;
}

.study-word { background: #fff; }
.study-word-name { margin: 0; font-size: 18px; font-weight: 750; }

.study-add {
  margin-top: 8px;
  border: 1px solid #99f6e4;
  border-radius: 999px;
  padding: 6px 12px;
  background: #f0fdfa;
  color: #0f766e;
  font-size: 13px;
  font-weight: 750;
}

.study-add:disabled { opacity: 0.7; cursor: default; }