/* ==========================================================================
   UA Living Spec Book: messages view
   The per-project conversation column. Crumb toolbar (reuses .sb-toolbar),
   day-grouped thread with own/other bubbles, and the auto-growing composer.
   Class prefix .msg-. Consumes tokens from css/tokens.css only.
   ========================================================================== */

.msg-page {
  width: 100%;
  max-width: 46rem;
  margin-inline: auto;
  padding-bottom: var(--ua-s7);
}

/* =======================
   Heading
   ======================= */
.msg-head {
  margin-top: var(--ua-s6);
}

.msg-head h1 {
  margin: 0;
  color: var(--ua-text-strong);
  font-family: var(--ua-font-display);
  font-size: var(--ua-fs-h2);
  font-weight: 400;
  letter-spacing: var(--ua-tracking-display);
  line-height: 1.15;
}

.msg-head p {
  margin: 0.4rem 0 0;
  font-size: var(--ua-fs-small);
  line-height: 1.5;
}

/* =======================
   Thread
   ======================= */
.msg-thread {
  display: flex;
  flex-direction: column;
  gap: var(--ua-s3);
  min-height: 14rem;
  max-height: min(58vh, 36rem);
  margin-top: var(--ua-s5);
  padding: var(--ua-s2) var(--ua-s1);
  overflow-y: auto;
  overscroll-behavior: contain;
}

.msg-thread__loading {
  margin: var(--ua-s5) 0;
  text-align: center;
}

.msg-thread .ua-empty {
  margin-block: auto;
}

/* Day divider: a quiet label between two hairlines */
.msg-day {
  display: flex;
  align-items: center;
  gap: var(--ua-s3);
  margin-block: var(--ua-s2);
  color: var(--ua-text-faint);
  font-size: var(--ua-fs-tiny);
  font-weight: 400;
  letter-spacing: var(--ua-tracking-caps);
  text-transform: uppercase;
}

.msg-day::before,
.msg-day::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--ua-line-soft);
}

/* =======================
   Message rows
   ======================= */
.msg-row {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.msg-row--own {
  align-items: flex-end;
}

.msg-row__bubble {
  max-width: min(82%, 34rem);
  padding: 0.65rem 0.95rem;
  border: 1px solid var(--ua-line-soft);
  border-radius: var(--ua-radius-lg);
  background: var(--ua-bg-card);
  color: var(--ua-text);
}

.msg-row--own .msg-row__bubble {
  border-color: var(--ua-ink);
  background: var(--ua-ink);
  color: var(--ua-text-on-ink);
}

.msg-row__meta {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  margin-bottom: 0.3rem;
  color: var(--ua-text-muted);
  font-size: var(--ua-fs-tiny);
}

.msg-row--own .msg-row__meta {
  justify-content: flex-end;
  color: var(--ua-text-on-ink-muted);
}

.msg-row__author {
  font-weight: 400;
  letter-spacing: 0.04em;
}

.msg-row__meta time {
  font-family: 'Lato', 'Helvetica Neue', Arial, sans-serif;
  font-variant-numeric: tabular-nums;
}

.msg-row__bubble p {
  margin: 0;
  font-size: var(--ua-fs-small);
  font-weight: 300;
  line-height: 1.55;
  overflow-wrap: anywhere;
  white-space: pre-wrap;
}

.msg-row__bubble p + p {
  margin-top: 0.45rem;
}

/* Failed optimistic send */
.msg-row.is-failed .msg-row__bubble {
  opacity: 0.55;
}

.msg-row__failed {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  margin: 0.3rem 0 0;
  color: var(--ua-status-danger);
  font-size: var(--ua-fs-tiny);
  letter-spacing: 0.04em;
}

/* Gentle entrance for appended rows */
@media (prefers-reduced-motion: no-preference) {
  .msg-row {
    animation: msg-row-in 200ms var(--ua-ease);
  }

  @keyframes msg-row-in {
    from {
      opacity: 0;
      transform: translateY(4px);
    }
  }
}

/* =======================
   Composer
   ======================= */
.msg-composer {
  display: flex;
  align-items: flex-end;
  gap: var(--ua-s2);
  margin-top: var(--ua-s4);
  padding-top: var(--ua-s4);
  border-top: 1px solid var(--ua-line-soft);
}

.msg-composer .msg-composer__input {
  flex: 1;
  min-height: 2.65rem;
  max-height: 9rem;
  overflow-y: auto;
  resize: none;
}

/* =======================
   Responsive
   ======================= */
@media (max-width: 600px) {
  .msg-thread {
    max-height: 55vh;
  }

  .msg-row__bubble {
    max-width: 92%;
  }

  .msg-composer__send span:not(.ua-icon) {
    display: none;
  }

  .msg-composer__send {
    min-width: 2.65rem;
    padding-inline: 0.75rem;
  }
}