/* ============================================================
   Feynman Study Mode — split-screen study partner UI
   ============================================================ */

.feynman-setup,
.feynman-session,
.feynman-report {
  animation: fadeInUp var(--duration-slow) var(--ease-out) both;
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 20px 48px;
}

/* ─── Setup ─── */
.feynman-setup__header {
  margin-bottom: 32px;
}

.feynman-setup__back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  margin-bottom: 20px;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-out);
}

.feynman-setup__back:hover {
  background: var(--color-bg-hover);
}

.feynman-setup__hero {
  text-align: center;
}

.feynman-setup__badge {
  display: inline-block;
  padding: 4px 10px;
  margin-bottom: 12px;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 12%, transparent);
  border-radius: var(--radius-full);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.feynman-setup__title {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  margin: 0 0 8px;
}

.feynman-setup__subtitle {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  max-width: 520px;
  margin: 0 auto;
  line-height: 1.5;
}

.feynman-setup__form {
  max-width: 480px;
  margin: 0 auto 32px;
}

.feynman-setup__steps {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 24px;
}

.feynman-setup__step {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.feynman-setup__arrow {
  text-align: center;
  color: var(--color-text-tertiary);
  font-size: var(--font-size-sm);
  line-height: 1;
}

.feynman-setup__label {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
}

.feynman-setup__select,
.feynman-setup__input {
  width: 100%;
  padding: 10px 12px;
  font-size: var(--font-size-base);
  color: var(--color-text-primary);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--duration-fast) var(--ease-out);
}

.feynman-setup__select:focus,
.feynman-setup__input:focus {
  outline: none;
  border-color: var(--color-accent);
}

.feynman-setup__input--alt {
  margin-top: 6px;
}

.feynman-setup__start {
  width: 100%;
}

.feynman-setup__features {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

.feynman-setup__feature {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
}

/* Workspace card accent */
.workspace-card--feynman .workspace-card__icon {
  color: var(--color-accent);
}

.workspace-card--feynman:hover .workspace-card__icon {
  background: color-mix(in srgb, var(--color-accent) 15%, transparent);
}

/* ─── Session split layout ─── */
.feynman-session__header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
}

.feynman-session__end {
  padding: 8px 14px;
  font-size: var(--font-size-sm);
  color: var(--color-danger, #e53e3e);
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-out);
}

.feynman-session__end:hover {
  background: color-mix(in srgb, var(--color-danger, #e53e3e) 8%, transparent);
}

.feynman-session__topic-info {
  flex: 1;
  min-width: 0;
}

.feynman-session__topic {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  margin: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.feynman-session__meta {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  margin: 2px 0 0;
}

.feynman-session__timer {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  white-space: nowrap;
}

.feynman-session__split {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 16px;
  min-height: calc(100vh - 220px);
}

.feynman-session__chat {
  display: flex;
  flex-direction: column;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.feynman-session__messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-height: 360px;
  max-height: calc(100vh - 320px);
}

.feynman-session__composer {
  padding: 12px 16px;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg-subtle);
}

/* ─── Messages ─── */
.feynman-msg {
  display: flex;
  gap: 10px;
  max-width: 92%;
}

.feynman-msg--user {
  flex-direction: row-reverse;
  align-self: flex-end;
}

.feynman-msg--partner {
  align-self: flex-start;
}

.feynman-msg__avatar {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-secondary);
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
}

.feynman-msg--partner .feynman-msg__avatar {
  color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 10%, transparent);
}

.feynman-msg__bubble {
  padding: 10px 14px;
  border-radius: var(--radius-lg);
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
}

.feynman-msg--user .feynman-msg__bubble {
  background: color-mix(in srgb, var(--color-accent) 12%, var(--color-bg-elevated));
  border-color: color-mix(in srgb, var(--color-accent) 25%, var(--color-border));
}

.feynman-msg--hint .feynman-msg__bubble {
  border-style: dashed;
  opacity: 0.95;
}

.feynman-msg__text {
  margin: 0;
  font-size: var(--font-size-base);
  line-height: 1.55;
  white-space: pre-wrap;
  word-break: break-word;
}

.feynman-msg__eval {
  margin: 8px 0 0;
  padding-top: 8px;
  border-top: 1px solid var(--color-border);
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
}

.feynman-msg__eval--correct { color: #38a169; }
.feynman-msg__eval--partial { color: #d69e2e; }
.feynman-msg__eval--incorrect { color: #e53e3e; }

.feynman-msg__time {
  display: block;
  margin-top: 6px;
  font-size: 10px;
  color: var(--color-text-tertiary);
}

.feynman-msg--typing .feynman-msg__bubble {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.feynman-typing {
  display: inline-flex;
  gap: 4px;
}

.feynman-typing span {
  width: 6px;
  height: 6px;
  background: var(--color-text-tertiary);
  border-radius: 50%;
  animation: feynmanBounce 1.2s infinite ease-in-out;
}

.feynman-typing span:nth-child(2) { animation-delay: 0.15s; }
.feynman-typing span:nth-child(3) { animation-delay: 0.3s; }

@keyframes feynmanBounce {
  0%, 80%, 100% { transform: translateY(0); opacity: 0.4; }
  40% { transform: translateY(-4px); opacity: 1; }
}

/* ─── Composer ─── */
.feynman-composer {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.feynman-composer__input {
  width: 100%;
  padding: 10px 12px;
  font-size: var(--font-size-base);
  font-family: inherit;
  color: var(--color-text-primary);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  resize: vertical;
  min-height: 56px;
}

.feynman-composer__input:focus {
  outline: none;
  border-color: var(--color-accent);
}

.feynman-composer__actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.feynman-composer__mic,
.feynman-composer__hint-btn,
.feynman-composer__skip {
  padding: 8px 12px;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-out);
}

.feynman-composer__mic:hover,
.feynman-composer__hint-btn:hover,
.feynman-composer__skip:hover {
  background: var(--color-bg-hover);
}

.feynman-composer__submit {
  margin-left: auto;
}

.feynman-composer__hint-wrap {
  position: relative;
}

.feynman-hint-menu {
  position: absolute;
  bottom: calc(100% + 6px);
  left: 0;
  min-width: 160px;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md, 0 8px 24px rgba(0,0,0,0.12));
  z-index: 10;
  overflow: hidden;
}

.feynman-hint-menu button {
  display: block;
  width: 100%;
  padding: 10px 14px;
  text-align: left;
  font-size: var(--font-size-sm);
  color: var(--color-text-primary);
  background: transparent;
  border: none;
  cursor: pointer;
}

.feynman-hint-menu button:hover {
  background: var(--color-bg-hover);
}

/* ─── Side panel ─── */
.feynman-session__panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
  overflow-y: auto;
  max-height: calc(100vh - 180px);
}

.feynman-panel__block {
  padding: 14px;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.feynman-panel__title {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin: 0 0 10px;
}

.feynman-live-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.feynman-live-stat {
  text-align: center;
  padding: 8px 4px;
  background: var(--color-bg-subtle);
  border-radius: var(--radius-md);
}

.feynman-live-stat span {
  display: block;
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
}

.feynman-live-stat label {
  font-size: 10px;
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.feynman-live-stat--ok span { color: #38a169; }
.feynman-live-stat--partial span { color: #d69e2e; }
.feynman-live-stat--wrong span { color: #e53e3e; }

.feynman-panel__current-q {
  margin: 12px 0 0;
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
  line-height: 1.4;
}

.feynman-panel__type {
  display: inline-block;
  margin-top: 8px;
  padding: 3px 8px;
  font-size: 10px;
  color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 10%, transparent);
  border-radius: var(--radius-full);
}

.feynman-panel__list {
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
}

.feynman-panel__list li {
  padding: 4px 0;
  border-bottom: 1px solid var(--color-border);
}

.feynman-panel__list li:last-child {
  border-bottom: none;
}

.feynman-panel__list--compact li {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.feynman-panel__empty {
  color: var(--color-text-tertiary);
  font-size: var(--font-size-xs);
}

.feynman-panel__chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.feynman-chip {
  padding: 3px 8px;
  font-size: 10px;
  color: var(--color-text-secondary);
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
}

/* ─── Report ─── */
.feynman-report__header {
  text-align: center;
  margin-bottom: 24px;
}

.feynman-report__title {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  margin: 0 0 4px;
}

.feynman-report__subtitle {
  color: var(--color-text-secondary);
  margin: 0;
}

.feynman-report__summary,
.feynman-report__encourage {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 12px;
  line-height: 1.55;
  color: var(--color-text-secondary);
}

.feynman-report__encourage {
  font-weight: var(--font-weight-medium);
  color: var(--color-accent);
  margin-bottom: 28px;
}

.feynman-report__scores {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-bottom: 28px;
}

.feynman-report__score {
  text-align: center;
  padding: 20px 12px;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.feynman-report__score-val {
  display: block;
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
}

.feynman-report__score-label {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.feynman-report__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  margin-bottom: 32px;
}

.feynman-report__section h3 {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  margin: 0 0 10px;
}

.feynman-report__section {
  padding: 16px;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.feynman-report__section ul {
  margin: 0;
  padding-left: 18px;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.feynman-report__revision-date {
  margin: 10px 0 0;
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
}

.feynman-report__footer {
  text-align: center;
}

/* ─── Mobile ─── */
@media (max-width: 900px) {
  .feynman-session__split {
    grid-template-columns: 1fr;
  }

  .feynman-session__panel {
    order: -1;
    max-height: none;
    flex-direction: row;
    flex-wrap: wrap;
    overflow-x: auto;
  }

  .feynman-panel__block {
    flex: 1 1 200px;
    min-width: 180px;
  }

  .feynman-report__scores {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .feynman-session__header {
    flex-wrap: wrap;
  }

  .feynman-composer__actions {
    justify-content: flex-end;
  }

  .feynman-composer__submit {
    width: 100%;
    margin-left: 0;
  }
}