#viewer {
	display: flex;
	flex-direction: row;
	align-items: stretch;
	width: 100%;
	height: calc(100vh - 160px);
	min-height: 420px;
	background: #0a0c12;
	border: 1px solid #1f2439;
	border-radius: 10px;
	overflow: hidden;
}

.panel {
	display: flex;
	flex-direction: column;
	min-width: 0;
	border-right: 1px solid #1f2439;
}

.panel:last-child {
	border-right: none;
}

#bus-panel {
	flex: 0 0 260px;
	background: #070910;
}

#node-panel {
	flex: 0 0 250px;
	background: #0b0e16;
}

#msg-panel {
	flex: 1 1 0;
	background: #0d1018;
}

.panel-header {
	flex-shrink: 0;
	padding: 12px 14px 10px;
	font-size: 0.7rem;
	font-weight: 700;
	text-transform: uppercase;
	letter-spacing: 0.14em;
	color: #7f8ca4;
	border-bottom: 1px solid #1f2439;
	background: rgba(5, 7, 12, 0.7);
}

.panel-list {
	flex: 1;
	overflow-y: auto;
	overflow-x: hidden;
	padding: 4px 0;
}

.panel-list::-webkit-scrollbar {
	width: 6px;
}

.panel-list::-webkit-scrollbar-track {
	background: transparent;
}

.panel-list::-webkit-scrollbar-thumb {
	background: #303b68;
	border-radius: 4px;
}

.placeholder {
	display: block;
	padding: 14px;
	font-size: 0.82rem;
	font-style: italic;
	color: #667189;
}

.panel-item {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 8px;
	padding: 9px 14px;
	font-size: 0.85rem;
	color: #b8c3d8;
	cursor: pointer;
	user-select: none;
	border-left: 3px solid transparent;
	transition:
		background 0.12s,
		color 0.12s,
		border-color 0.12s;
}

.panel-item:hover {
	background: #11172a;
	color: #f8fafc;
}

.panel-item.active {
	background: #151d33;
	color: #ffffff;
	border-left-color: #8b5cf6;
}

.item-label {
	flex: 1 1 auto;
	min-width: 0;
	word-break: break-word;
}

.item-chevron {
	flex-shrink: 0;
	color: #67728b;
}

body.is-mobile .item-chevron {
	display: none;
}

.item-accent {
	flex: 0 0 auto;
	font-size: 0.68rem;
	font-family: "Fira Mono", "Consolas", monospace;
	color: #d8b4fe;
	background: rgba(91, 33, 182, 0.25);
	border: 1px solid rgba(167, 139, 250, 0.35);
	padding: 1px 6px;
	border-radius: 999px;
	margin-left: 4px;
}

.item-accent-custom {
	color: #fdba74;
	background: rgba(194, 65, 12, 0.25);
	border-color: rgba(251, 146, 60, 0.35);
}

.panel-item.active .item-chevron {
	color: #8b5cf6;
}

.msg-item {
	display: flex;
	flex-direction: column;
	align-items: flex-start;
	gap: 5px;
	padding: 10px 14px;
	border-left-color: transparent;
	cursor: default;
}

.msg-item:hover {
	background: #11162a;
}

.msg-name {
	font-size: 0.86rem;
	font-weight: 500;
	color: #f8fafc;
}

.msg-meta {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: 6px;
}

.msg-badge {
	display: inline-block;
	padding: 2px 7px;
	border-radius: 999px;
	font-size: 0.68rem;
	font-family: "Fira Mono", "Consolas", monospace;
	background: #3b1157;
	color: #e9d5ff;
}

.msg-receivers {
	font-size: 0.76rem;
	color: #9babca;
}

.msg-bytes {
	margin-top: 4px;
	width: 100%;
	border-top: 1px solid #1f2439;
	padding-top: 6px;
}

.msg-byte-row {
	font-size: 0.74rem;
	line-height: 1.35;
	margin-bottom: 5px;
	color: #b9c3da;
}

.msg-byte-main {
	color: #dbe6ff;
}

.msg-type-chip {
	display: inline-block;
	margin-left: 6px;
	padding: 1px 6px;
	border-radius: 999px;
	font-size: 0.63rem;
	font-family: "Fira Mono", "Consolas", monospace;
	color: #c4b5fd;
	background: rgba(91, 33, 182, 0.2);
	border: 1px solid rgba(167, 139, 250, 0.3);
	vertical-align: middle;
}

.msg-byte-bits {
	color: #9aa8c8;
}

.msg-map-equation {
	display: inline-block;
	margin-left: 6px;
	padding: 1px 6px;
	border-radius: 999px;
	font-size: 0.63rem;
	font-family: "Fira Mono", "Consolas", monospace;
	color: #6ee7b7;
	background: rgba(16, 185, 129, 0.12);
	border: 1px solid rgba(52, 211, 153, 0.3);
	vertical-align: middle;
}

.msg-scaled-range {
	display: inline-block;
	margin-left: 6px;
	padding: 1px 6px;
	border-radius: 999px;
	font-size: 0.63rem;
	font-family: "Fira Mono", "Consolas", monospace;
	color: #93c5fd;
	background: rgba(59, 130, 246, 0.12);
	border: 1px solid rgba(147, 197, 253, 0.3);
	vertical-align: middle;
}

.msg-byte-comment {
	margin-top: 1px;
	color: #7f8ca6;
	font-style: italic;
}

#viewer-search-row {
	padding: 0 0 8px;
	position: relative;
}

#viewer-search {
	width: 100%;
	font-family: inherit;
	font-size: 0.82rem;
	padding: 8px 12px;
	border-radius: 8px;
	border: 1px solid #2c3350;
	background: #0a0c13;
	color: #ecf2ff;
	outline: none;
	transition:
		border-color 0.16s,
		box-shadow 0.16s;
}

#viewer-search:focus {
	border-color: #7c3aed;
	box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.2);
}

#viewer-search::placeholder {
	color: #667189;
}

#search-dropdown {
	display: none;
	position: absolute;
	top: calc(100% - 8px);
	left: 0;
	right: 0;
	z-index: 50;
	background: #0d1020;
	border: 1px solid #2c3350;
	border-top: none;
	border-radius: 0 0 8px 8px;
	box-shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
	max-height: 280px;
	overflow-y: auto;
}

.search-result-row {
	display: flex;
	flex-direction: column;
	gap: 2px;
	padding: 8px 12px;
	cursor: pointer;
	border-bottom: 1px solid #1a1f35;
	transition: background 0.1s;
}

.search-result-row:last-child {
	border-bottom: none;
}

.search-result-row:hover,
.search-result-row.sr-focused {
	background: #151d33;
}

.sr-name-row {
	display: flex;
	align-items: center;
	gap: 6px;
}

.sr-kind {
	font-size: 0.62rem;
	font-weight: 600;
	letter-spacing: 0.05em;
	text-transform: uppercase;
	padding: 1px 6px;
	border-radius: 3px;
	flex-shrink: 0;
}

.sr-kind-node {
	background: rgba(96, 165, 250, 0.18);
	color: #93c5fd;
}

.sr-kind-message {
	background: rgba(139, 92, 246, 0.18);
	color: #c4b5fd;
}

.sr-kind-signal {
	background: rgba(34, 197, 94, 0.18);
	color: #86efac;
}

.sr-name {
	font-size: 0.84rem;
	font-weight: 500;
	color: #f0f4ff;
	overflow: hidden;
	text-overflow: ellipsis;
	white-space: nowrap;
}

.sr-path {
	font-size: 0.72rem;
	color: #667189;
	overflow: hidden;
	text-overflow: ellipsis;
	white-space: nowrap;
}

.sr-match {
	color: #f59e0b;
	font-weight: 600;
}

@keyframes highlight-fade {
	0% {
		background: rgba(139, 92, 246, 0.35);
	}
	100% {
		background: transparent;
	}
}

.msg-highlight {
	animation: highlight-fade 1.8s ease-out forwards;
	border-radius: 4px;
}

/* ── Mobile: hide expand arrow; tap name row to expand instead ── */
.is-mobile .msg-expand-btn {
	display: none;
}

.is-mobile .msg-name-row-tappable {
	cursor: pointer;
}

.is-mobile .msg-name-row-tappable:focus-visible {
	outline: 2px solid #8b5cf6;
	outline-offset: 2px;
	border-radius: 4px;
}

.is-mobile .msg-name-row-tappable:active {
	background: rgba(124, 58, 237, 0.08);
	border-radius: 4px;
}

/* ── Message expand/collapse toggle ── */
.msg-expand-btn {
	flex-shrink: 0;
	background: transparent;
	border: 0;
	color: #8b5cf6;
	cursor: pointer;
	font-size: 0.82rem;
	line-height: 1;
	padding: 0 2px;
	transform: rotate(90deg);
	transition:
		transform 0.12s,
		color 0.12s;
	user-select: none;
}

.msg-expand-btn.collapsed {
	transform: rotate(0deg);
	color: #67728b;
}

.msg-details {
	width: 100%;
	overflow: hidden;
	max-height: 600px;
	transition: max-height 0.15s ease-out;
}

.msg-details.collapsed {
	max-height: 0;
}

/* ── Desktop: viewer-track is transparent (panels participate directly in #viewer's flex) ── */
body:not(.is-mobile) .viewer-track {
	display: contents;
}

/* ──────────────────────────────────────────────────────────────────────
   Mobile drill-down (≤768px): three panels become a horizontally
   translating track. Track width and step indices are coupled to the
   number of panels — adding a 4th step requires bumping `width: 300vw`,
   the translateX amounts, and the MobileNav step ceiling in viewer.js.
   ────────────────────────────────────────────────────────────────────── */
@media (max-width: 768px) {
	#viewer {
		flex-direction: row;
		overflow: hidden;
		height: calc(100dvh - 56px - 56px); /* appbar (56) + search row (~56) */
		min-height: 0;
		border-radius: 8px;
	}

	.viewer-track {
		display: flex;
		flex-direction: row;
		width: 300vw;
		height: 100%;
		transition: transform 0.25s ease-out;
		will-change: transform;
	}

	#viewer[data-step="0"] .viewer-track {
		transform: translateX(0);
	}
	#viewer[data-step="1"] .viewer-track {
		transform: translateX(-100vw);
	}
	#viewer[data-step="2"] .viewer-track {
		transform: translateX(-200vw);
	}

	.panel {
		flex: 0 0 100vw;
		max-width: 100vw;
		border-right: none;
	}

	#bus-panel,
	#node-panel,
	#msg-panel {
		flex: 0 0 100vw;
	}

	.panel-item {
		min-height: 48px;
		padding: 12px 14px;
		font-size: 0.95rem;
	}

	.msg-item {
		min-height: 56px;
		padding: 14px;
		font-size: 0.95rem;
	}

	.msg-name {
		font-size: 0.95rem;
	}

	.panel-header {
		padding: 14px 16px 12px;
		font-size: 0.74rem;
	}

	#viewer-search-row {
		padding: 0 0 10px;
	}

	#viewer-search {
		font-size: 16px; /* iOS zoom-on-focus prevention */
		padding: 11px 14px;
		min-height: 44px;
	}

	#search-dropdown {
		max-height: 60dvh;
	}

	.search-result-row {
		min-height: 48px;
		padding: 10px 14px;
	}

	.sr-name {
		font-size: 0.92rem;
	}
}