/* ═══════════════════════════════════════════════════════════════════════════
   CRONY — timeline.css   v2.0.0
   Event Timeline screen.

   Actual HTML tree rendered by timeline.js:
     #screen-timeline                  — .screen root
       .screen-header                  — global (styles.css)
         #timeline-refresh-btn
       .kpi-row
         #tl-kpi-total / #tl-kpi-success / #tl-kpi-failed / #tl-kpi-pending
       #timeline-toolbar (.toolbar)
         #timeline-filter              — <select> event type
         #timeline-device-filter       — <select> device
         #timeline-search              — <input> search
       #timeline-list                  — <ul>
         .timeline-item                — <li> (JS-injected)
           .timeline-icon              — emoji/icon span
           .timeline-body              — content div
             .timeline-time            — timestamp
             .timeline-msg             — message text
       #timeline-empty
       #timeline-load-more

   Depends on: tokens.css, styles.css
   ═══════════════════════════════════════════════════════════════════════════ */


/* ── 1. Screen root ───────────────────────────────────────────────────────── */
#screen-timeline.active {
  scrollbar-width: thin;
  scrollbar-color: var(--divider) transparent;
}
#screen-timeline.active::-webkit-scrollbar { width: 4px; }
#screen-timeline.active::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 4px;
}


/* ── 2. KPI tile colour accents ───────────────────────────────────────────── */
#tl-kpi-success .kpi-value { color: var(--color-success, #2F4F3A); }
#tl-kpi-failed  .kpi-value { color: var(--color-error,   #9b1c1c); }
#tl-kpi-pending .kpi-value { color: var(--color-warning, #92400e); }


/* ── 3. Toolbar ───────────────────────────────────────────────────────────── */
#timeline-toolbar {
  padding-bottom: var(--space-2);
}
#timeline-filter,
#timeline-device-filter {
  flex: 0 1 160px;
  min-width: 120px;
}
#timeline-search {
  flex: 1 1 200px;
  min-width: 140px;
}
.timeline-filter-disabled {
  opacity: 0.5;
  cursor: not-allowed;
}


/* ── 4. Timeline list container ───────────────────────────────────────────── */
#timeline-list {
  list-style: none;
  margin: 0 var(--space-6);
  padding: var(--space-2) 0 var(--space-4);
  display: flex;
  flex-direction: column;
  gap: 0;
  position: relative;
}

/* Vertical connector line */
#timeline-list::before {
  content: '';
  position: absolute;
  left: 19px;
  top: 20px;
  bottom: 20px;
  width: 2px;
  background: linear-gradient(
    to bottom,
    transparent,
    var(--color-border) 8%,
    var(--color-border) 92%,
    transparent
  );
  border-radius: 2px;
  pointer-events: none;
  z-index: 0;
}


/* ── 5. Individual timeline item ──────────────────────────────────────────── */
.timeline-item {
  --tl-accent: var(--accent);

  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 0 var(--space-3);
  padding: var(--space-3) var(--space-2) var(--space-3) 0;
  position: relative;
  border-radius: var(--radius-lg);
  transition:
    background var(--transition-fast),
    box-shadow  var(--transition-fast);
  animation: tl-fade-in 240ms cubic-bezier(0.16, 1, 0.3, 1) both;
}
.timeline-item:hover {
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
}
.timeline-item + .timeline-item {
  margin-top: var(--space-1);
}
/* Hairline divider between items */
.timeline-item + .timeline-item::after {
  content: '';
  position: absolute;
  top: 0;
  left: 40px;
  right: 0;
  height: 1px;
  background: var(--divider);
}
.timeline-item:hover + .timeline-item::after,
.timeline-item:hover::after { opacity: 0; }

@keyframes tl-fade-in {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0);   }
}


/* ── 5a. Icon column (the dot + emoji) ────────────────────────────────────── */
.timeline-icon {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 3px;
  font-size: 1rem;
  line-height: 1;
  position: relative;
  z-index: 1;
  /* Circle backdrop behind the emoji */
  width: 32px;
  height: 32px;
  margin: 0 auto;
  border-radius: 50%;
  background: var(--bg-card);
  border: 2px solid var(--color-border);
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition:
    background var(--transition-fast),
    border-color var(--transition-fast),
    transform var(--transition-fast);
}
.timeline-item:hover .timeline-icon {
  background: var(--color-primary-highlight);
  border-color: var(--color-primary-dim);
  transform: scale(1.1);
}


/* ── 5b. Event-type accent colours ───────────────────────────────────────── */
.timeline-item--session_created  .timeline-icon { border-color: rgba(47, 79, 58, 0.35);  background: rgba(47, 79, 58, 0.07);  }
.timeline-item--plan_generated   .timeline-icon { border-color: rgba(3, 105, 161, 0.30); background: rgba(3, 105, 161, 0.07); }
.timeline-item--code_review_done .timeline-icon { border-color: rgba(109, 40, 217, 0.30); background: rgba(109, 40, 217, 0.07); }
.timeline-item--firmware_requested .timeline-icon { border-color: rgba(47, 79, 58, 0.35); background: rgba(47, 79, 58, 0.07); }
.timeline-item--firmware_built   .timeline-icon { border-color: rgba(47, 79, 58, 0.40);  background: rgba(47, 79, 58, 0.10);  }
.timeline-item--firmware_failed  .timeline-icon { border-color: rgba(155, 28, 28, 0.35); background: rgba(155, 28, 28, 0.07); }
.timeline-item--firmware_flashed .timeline-icon { border-color: rgba(124, 58, 237, 0.30); background: rgba(124, 58, 237, 0.07); }
.timeline-item--device_registered .timeline-icon { border-color: rgba(3, 105, 161, 0.30); background: rgba(3, 105, 161, 0.07); }
.timeline-item--device_heartbeat .timeline-icon { border-color: rgba(47, 79, 58, 0.25);  background: rgba(47, 79, 58, 0.05);  }
.timeline-item--device_deleted   .timeline-icon { border-color: rgba(155, 28, 28, 0.30); background: rgba(155, 28, 28, 0.07); }


/* ── 5c. Body column ──────────────────────────────────────────────────────── */
.timeline-body {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  min-width: 0;
  padding: 2px 0 var(--space-2);
}

.timeline-time {
  font-size: var(--text-xs);
  color: var(--text-kicker);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
  line-height: 1.4;
}

.timeline-msg {
  font-size: var(--text-sm);
  color: var(--text-body);
  line-height: 1.55;
  font-weight: 450;
  /* Clamp to 3 lines, expand on hover */
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  transition: none;
}
.timeline-item:hover .timeline-msg {
  -webkit-line-clamp: unset;
  display: block;
}


/* ── 5d. Type-specific left-border accent stripe ─────────────────────────── */
.timeline-item--firmware_failed,
.timeline-item--device_deleted {
  border-left: 3px solid rgba(155, 28, 28, 0.4);
  padding-left: var(--space-2);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}
.timeline-item--firmware_built,
.timeline-item--firmware_flashed {
  border-left: 3px solid rgba(47, 79, 58, 0.35);
  padding-left: var(--space-2);
  border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
}


/* ── 6. Date group separator (.tl-date-sep, JS-injected) ─────────────────── */
.tl-date-sep {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) 0 var(--space-2);
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--text-kicker);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  user-select: none;
}
.tl-date-sep::before,
.tl-date-sep::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--divider);
  border-radius: 1px;
}


/* ── 7. Empty state ───────────────────────────────────────────────────────── */
#timeline-empty {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  text-align: center;
  padding: var(--space-16) var(--space-6);
  color: var(--text-kicker);
}
#timeline-empty.visible,
#timeline-empty[style*="display: block"] {
  display: flex;
}
#timeline-empty svg {
  opacity: 0.4;
}
#timeline-empty p {
  margin: 0;
  font-size: var(--text-sm);
  line-height: 1.6;
  max-width: 280px;
}
#timeline-empty strong {
  display: block;
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--text-body);
  margin-bottom: var(--space-1);
}


/* ── 8. Load-more button ──────────────────────────────────────────────────── */
#timeline-load-more {
  display: block;
  margin: var(--space-4) auto var(--space-8);
  min-width: 160px;
}
#timeline-load-more[hidden],
#timeline-load-more.hidden { display: none !important; }


/* ── 9. Loading shimmer (optional, if JS adds .tl-loading) ───────────────── */
.tl-loading-shimmer {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin: 0 var(--space-6);
  padding: var(--space-4) 0;
}
.tl-shimmer-row {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 0 var(--space-3);
  padding: var(--space-3) 0;
}
.tl-shimmer-icon,
.tl-shimmer-line {
  background: linear-gradient(
    90deg,
    var(--color-border) 25%,
    var(--color-surface-offset, var(--bg-card)) 50%,
    var(--color-border) 75%
  );
  background-size: 200% 100%;
  animation: tl-shimmer 1.4s ease-in-out infinite;
  border-radius: var(--radius-md);
}
.tl-shimmer-icon {
  width: 32px;
  height: 32px;
  border-radius: 50%;
}
.tl-shimmer-body { display: flex; flex-direction: column; gap: var(--space-2); }
.tl-shimmer-line { height: 12px; }
.tl-shimmer-line:first-child { width: 40%; }
.tl-shimmer-line:last-child  { width: 72%; height: 10px; }

@keyframes tl-shimmer {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}


/* ── 10. Responsive ───────────────────────────────────────────────────────── */
@media (max-width: 1024px) {
  #timeline-list { margin: 0 var(--space-4); }
  #timeline-filter,
  #timeline-device-filter { flex: 0 1 140px; }
}

@media (max-width: 768px) {
  #timeline-list { margin: 0 var(--space-3); }

  #timeline-list::before { left: 15px; }

  .timeline-item {
    grid-template-columns: 32px 1fr;
    gap: 0 var(--space-2);
    padding: var(--space-2) var(--space-1) var(--space-2) 0;
  }
  .timeline-icon {
    width: 26px;
    height: 26px;
    font-size: 0.8rem;
  }
  .timeline-msg { -webkit-line-clamp: 2; }

  #timeline-filter,
  #timeline-device-filter { flex: 1 1 120px; min-width: 100px; }
  #timeline-search         { flex: 1 1 140px; }
}

@media (max-width: 480px) {
  #timeline-list {
    margin: 0 var(--space-2);
  }
  #timeline-list::before { left: 12px; }

  .timeline-item {
    grid-template-columns: 28px 1fr;
    gap: 0 var(--space-2);
    padding: var(--space-2) 0;
  }
  .timeline-icon {
    width: 24px;
    height: 24px;
    font-size: 0.75rem;
  }
  .timeline-time { font-size: 0.66rem; }
  .timeline-msg  { font-size: 0.8rem;  -webkit-line-clamp: 2; }

  /* No lift on mobile — prevents layout jank */
  .timeline-item:hover { transform: none; }

  #timeline-load-more { min-width: 120px; }

  /* Failure/success stripes hidden below 480 to save space */
  .timeline-item--firmware_failed,
  .timeline-item--device_deleted,
  .timeline-item--firmware_built,
  .timeline-item--firmware_flashed {
    border-left: none;
    padding-left: 0;
    border-radius: var(--radius-lg);
  }
}

@media (max-width: 360px) {
  .timeline-item { grid-template-columns: 24px 1fr; }
  .timeline-icon  { width: 20px; height: 20px; font-size: 0.65rem; }
  .timeline-time  { font-size: 0.60rem; }
  .timeline-msg   { font-size: 0.75rem; }
}