/* ============================================================================
 * HTTP PROTOCOL SIMULATOR - STYLESHEET
 * ============================================================================ */

:root {
	--color-bg-deep: #0f0d0b;
	--color-bg-panel: #1a1612;
	--color-bg-elevated: #252019;
	--color-border-dim: rgba(255, 255, 255, 0.06);
	--color-border-medium: rgba(255, 255, 255, 0.12);
	--color-text-bright: #f5f2ed;
	--color-text-mid: #b8b0a4;
	--color-text-dim: #6b6358;
	--color-accent-teal: #6ba3b8;
	--color-accent-rose: #c97a8d;
	--color-accent-sage: #7ab893;
	--color-accent-gold: #c9a86a;
	--color-accent-amber: #c98f5a;
	--color-accent-coral: #c96b6b;
	--color-accent-cyan: var(--color-accent-teal);
	--color-accent-magenta: var(--color-accent-rose);
	--color-accent-green: var(--color-accent-sage);
	--color-accent-yellow: var(--color-accent-gold);
	--color-accent-orange: var(--color-accent-amber);
	--color-accent-red: var(--color-accent-coral);
	--color-stream-0: #6ba3b8;
	--color-stream-1: #c97a8d;
	--color-stream-2: #7ab893;
	--color-stream-3: #c9a86a;
	--font-display: "Inter", "Space Grotesk", system-ui, sans-serif;
	--font-mono: "JetBrains Mono", "Fira Code", monospace;
	--space-xs: 4px;
	--space-sm: 8px;
	--space-md: 16px;
	--space-lg: 24px;
	--space-xl: 32px;
	--space-2xl: 48px;
	--radius-sm: 4px;
	--radius-md: 8px;
	--radius-lg: 12px;
	--radius-xl: 16px;
	--radius-full: 9999px;
	--transition-fast: 150ms ease;
	--transition-normal: 250ms ease;
	--transition-slow: 400ms ease;
	--shadow-elevated: 0 16px 48px rgba(0, 0, 0, 0.5);
	--glow-teal: 0 0 20px rgba(107, 163, 184, 0.35);
	--glow-sage: 0 0 20px rgba(122, 184, 147, 0.35);
	--glow-coral: 0 0 20px rgba(201, 107, 107, 0.35);
	--glow-cyan: var(--glow-teal);
	--glow-green: var(--glow-sage);
	--glow-red: var(--glow-coral);
}

*,
*::before,
*::after {
	box-sizing: border-box;
	margin: 0;
	padding: 0;
}
html {
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
}
body {
	font-family: var(--font-display);
	background-color: var(--color-bg-deep);
	color: var(--color-text-bright);
	min-height: 100vh;
	overflow-x: hidden;
	line-height: 1.5;
}
body::before {
	content: "";
	position: fixed;
	inset: 0;
	background-image:
		linear-gradient(rgba(201, 168, 106, 0.025) 1px, transparent 1px),
		linear-gradient(90deg, rgba(201, 168, 106, 0.025) 1px, transparent 1px);
	background-size: 40px 40px;
	pointer-events: none;
	z-index: -1;
}

.container {
	max-width: 1500px;
	margin-inline: auto;
	padding: var(--space-lg) var(--space-md) var(--space-2xl);
}

header {
	text-align: center;
	margin-block-end: var(--space-lg);
}
header h1 {
	font-size: clamp(1.5rem, 4vw, 2.2rem);
	font-weight: 300;
	letter-spacing: 0.12em;
	text-transform: uppercase;
	background: linear-gradient(
		135deg,
		var(--color-accent-teal),
		var(--color-accent-gold)
	);
	background-clip: text;
	-webkit-background-clip: text;
	-webkit-text-fill-color: transparent;
	margin-block-end: var(--space-sm);
}
.subtitle {
	color: var(--color-text-mid);
	font-size: 0.95rem;
}

.scenario-box {
	background: linear-gradient(
		135deg,
		rgba(107, 163, 184, 0.06),
		rgba(201, 168, 106, 0.06)
	);
	border: 1px solid rgba(201, 168, 106, 0.2);
	border-radius: var(--radius-lg);
	padding: var(--space-md) var(--space-lg);
	margin-block-end: var(--space-lg);
	text-align: center;
}
.scenario-box h2 {
	font-size: 1rem;
	color: var(--color-accent-gold);
	margin-block-end: var(--space-sm);
	font-weight: 500;
}
.scenario-box p {
	color: var(--color-text-mid);
	font-size: 0.9rem;
	line-height: 1.5;
}
.scenario-box strong {
	color: var(--color-text-bright);
}

.controls {
	position: sticky;
	top: var(--space-md);
	z-index: 100;
	background: rgba(10, 11, 16, 0.97);
	backdrop-filter: blur(16px);
	-webkit-backdrop-filter: blur(16px);
	border: 1px solid var(--color-border-dim);
	border-radius: var(--radius-lg);
	padding: var(--space-md) var(--space-lg);
	margin-block-end: var(--space-lg);
	display: flex;
	flex-wrap: wrap;
	justify-content: center;
	align-items: center;
	gap: var(--space-md);
	box-shadow: var(--shadow-elevated);
}

.btn {
	font-family: var(--font-mono);
	font-size: 0.8rem;
	font-weight: 600;
	padding: var(--space-sm) var(--space-md);
	border: none;
	border-radius: var(--radius-md);
	cursor: pointer;
	text-transform: uppercase;
	letter-spacing: 0.08em;
	transition:
		transform var(--transition-fast),
		box-shadow var(--transition-fast),
		background-color var(--transition-fast);
}
.btn:active {
	transform: scale(0.97);
}
.btn:disabled {
	opacity: 0.5;
	cursor: not-allowed;
}
.btn-primary {
	background: linear-gradient(135deg, var(--color-accent-gold), #a88545);
	color: #000;
}
.btn-primary:hover:not(:disabled) {
	box-shadow: 0 0 20px rgba(201, 168, 106, 0.4);
}
.btn-secondary {
	background: var(--color-bg-elevated);
	color: var(--color-text-mid);
	border: 1px solid var(--color-border-dim);
}
.btn-secondary:hover:not(:disabled) {
	border-color: var(--color-accent-cyan);
	color: var(--color-text-bright);
}

.speed-control {
	display: flex;
	align-items: center;
	gap: var(--space-sm);
	padding-inline: var(--space-md);
	border-inline-start: 1px solid var(--color-border-dim);
}
.speed-control label,
.loss-control label {
	font-family: var(--font-mono);
	font-size: 0.7rem;
	color: var(--color-text-dim);
	text-transform: uppercase;
}
.speed-control input[type="range"] {
	width: 80px;
	accent-color: var(--color-accent-cyan);
}
.speed-value {
	font-family: var(--font-mono);
	font-size: 0.8rem;
	color: var(--color-accent-cyan);
	min-width: 36px;
}

.loss-control {
	display: flex;
	align-items: center;
	gap: var(--space-sm);
	padding-inline-start: var(--space-md);
	border-inline-start: 1px solid var(--color-border-dim);
}
.loss-buttons {
	display: flex;
	gap: 6px;
}
.btn-loss {
	padding: 6px 10px;
	font-size: 0.7rem;
	background: transparent;
	border: 1px solid var(--color-accent-red);
	color: var(--color-accent-red);
	border-radius: var(--radius-sm);
}
.btn-loss[data-packet="3"] {
	border-color: var(--color-stream-0);
	color: var(--color-stream-0);
}
.btn-loss[data-packet="6"] {
	border-color: var(--color-stream-1);
	color: var(--color-stream-1);
}
.btn-loss[data-packet="10"] {
	border-color: var(--color-stream-2);
	color: var(--color-stream-2);
}
.btn-loss[data-packet="14"] {
	border-color: var(--color-stream-3);
	color: var(--color-stream-3);
}
.btn-loss:hover:not(:disabled) {
	background: var(--color-accent-red);
	color: #fff;
}
.btn-loss[data-packet="3"]:hover:not(:disabled) {
	background: var(--color-stream-0);
	color: #000;
}
.btn-loss[data-packet="6"]:hover:not(:disabled) {
	background: var(--color-stream-1);
	color: #000;
}
.btn-loss[data-packet="10"]:hover:not(:disabled) {
	background: var(--color-stream-2);
	color: #000;
}
.btn-loss[data-packet="14"]:hover:not(:disabled) {
	background: var(--color-stream-3);
	color: #000;
}
.btn-loss:disabled {
	border-color: var(--color-text-dim);
	color: var(--color-text-dim);
}
.btn-loss.active {
	background: var(--color-accent-red);
	color: #fff;
	box-shadow: var(--glow-red);
}

.protocol-row {
	background: var(--color-bg-panel);
	border: 1px solid var(--color-border-dim);
	border-radius: var(--radius-lg);
	margin-block-end: var(--space-md);
	overflow: hidden;
	display: grid;
	grid-template-columns: 220px 1fr 220px;
	min-height: 320px;
	position: relative;
}
.protocol-row::before {
	content: "";
	position: absolute;
	top: 0;
	left: 0;
	right: 0;
	height: 3px;
	background: var(--row-accent);
	opacity: 0.7;
}
.protocol-row[data-protocol="h1"] {
	--row-accent: var(--color-accent-cyan);
}
.protocol-row[data-protocol="h2"] {
	--row-accent: var(--color-accent-magenta);
}
.protocol-row[data-protocol="h3"] {
	--row-accent: var(--color-accent-green);
}

.panel {
	padding: var(--space-md);
	display: flex;
	flex-direction: column;
	background: var(--color-bg-elevated);
}
.panel-left {
	border-inline-end: 1px solid var(--color-border-dim);
}
.panel-right {
	border-inline-start: 1px solid var(--color-border-dim);
}
.panel-header {
	display: flex;
	justify-content: space-between;
	align-items: center;
	margin-block-end: var(--space-sm);
}
.panel-title {
	font-family: var(--font-mono);
	font-size: 0.65rem;
	text-transform: uppercase;
	letter-spacing: 0.15em;
	color: var(--color-text-dim);
}
.panel-label {
	font-size: 0.7rem;
	color: var(--row-accent);
	font-weight: 600;
}
.app-section {
	margin-block-end: var(--space-md);
}
.section-label {
	font-family: var(--font-mono);
	font-size: 0.6rem;
	color: var(--color-text-dim);
	text-transform: uppercase;
	letter-spacing: 0.1em;
	margin-block-end: 6px;
	display: flex;
	align-items: center;
	gap: 6px;
}
.section-label .indicator {
	width: 8px;
	height: 8px;
	border-radius: 2px;
}
.stats-row {
	display: flex;
	gap: var(--space-sm);
	margin-block-start: var(--space-sm);
	flex-wrap: wrap;
}
.stat {
	font-family: var(--font-mono);
	font-size: 0.65rem;
	color: var(--color-text-dim);
}
.stat span {
	color: var(--color-accent-cyan);
}
.stat-highlight {
	font-size: 0.75rem;
	padding: var(--space-xs) var(--space-sm);
	background: rgba(0, 0, 0, 0.3);
	border-radius: var(--radius-sm);
	border: 1px solid var(--color-border-dim);
}
.stat-highlight span {
	font-weight: 700;
	font-size: 0.85rem;
}

.progress-section {
	margin-block-start: var(--space-sm);
	padding-block-start: var(--space-sm);
	border-block-start: 1px solid var(--color-border-dim);
}
.progress-label {
	display: flex;
	justify-content: space-between;
	font-family: var(--font-mono);
	font-size: 0.6rem;
	color: var(--color-text-dim);
	text-transform: uppercase;
	letter-spacing: 0.1em;
	margin-block-end: 6px;
}
.progress-value {
	color: var(--color-accent-sage);
	font-weight: 600;
}
.progress-bar {
	height: 8px;
	background: rgba(0, 0, 0, 0.4);
	border-radius: var(--radius-full);
	overflow: hidden;
	border: 1px solid var(--color-border-dim);
}
.progress-fill {
	height: 100%;
	width: 0%;
	background: linear-gradient(
		90deg,
		var(--color-accent-sage),
		var(--color-accent-teal)
	);
	border-radius: var(--radius-full);
	transition: width 0.3s ease;
}
.progress-fill.blocked {
	background: linear-gradient(
		90deg,
		var(--color-accent-coral),
		var(--color-accent-amber)
	);
}

.image-grid {
	display: grid;
	grid-template-columns: repeat(2, 1fr);
	gap: 6px;
	position: relative;
}
.image-quadrant {
	display: grid;
	grid-template-columns: repeat(2, 1fr);
	gap: 2px;
	padding: var(--space-xs);
	background: rgba(255, 255, 255, 0.02);
	border-radius: var(--radius-sm);
	border: 1px solid var(--color-border-dim);
	justify-items: center;
	transition:
		background-color var(--transition-normal),
		border-color var(--transition-normal),
		box-shadow var(--transition-normal);
}
.image-quadrant.stream-0 {
	border-color: rgba(107, 163, 184, 0.35);
}
.image-quadrant.stream-1 {
	border-color: rgba(201, 122, 141, 0.35);
}
.image-quadrant.stream-2 {
	border-color: rgba(122, 184, 147, 0.35);
}
.image-quadrant.stream-3 {
	border-color: rgba(201, 168, 106, 0.35);
}
.quadrant-label {
	font-family: var(--font-mono);
	font-size: 0.5rem;
	color: var(--color-text-dim);
	text-align: center;
	grid-column: span 2;
	margin-block-end: 2px;
}
.image-quadrant.stream-0 .quadrant-label {
	color: var(--color-stream-0);
}
.image-quadrant.stream-1 .quadrant-label {
	color: var(--color-stream-1);
}
.image-quadrant.stream-2 .quadrant-label {
	color: var(--color-stream-2);
}
.image-quadrant.stream-3 .quadrant-label {
	color: var(--color-stream-3);
}
.image-quadrant.complete {
	background: rgba(122, 184, 147, 0.15);
	border-color: var(--color-accent-sage);
	box-shadow: 0 0 12px rgba(122, 184, 147, 0.25);
}
.image-quadrant.complete .quadrant-label {
	color: var(--color-accent-sage);
}
.image-quadrant.complete .quadrant-label::after {
	content: " ✓";
}
.image-quadrant.blocked {
	background: rgba(201, 107, 107, 0.15);
	border-color: var(--color-accent-coral);
	animation: quadrant-blocked 0.5s infinite;
}
.image-quadrant.blocked .quadrant-label {
	color: var(--color-accent-coral);
}
.image-quadrant.blocked .quadrant-label::after {
	content: " ✗";
}

.grid-cell {
	width: 28px;
	height: 28px;
	background: rgba(255, 255, 255, 0.02);
	border: 1px solid var(--color-border-dim);
	border-radius: var(--radius-sm);
	display: flex;
	align-items: center;
	justify-content: center;
	font-family: var(--font-mono);
	font-size: 0.65rem;
	color: var(--color-text-dim);
	transition:
		background-color var(--transition-fast),
		border-color var(--transition-fast),
		transform var(--transition-fast),
		box-shadow var(--transition-fast);
}
.grid-cell.delivered {
	background: var(--color-accent-sage);
	border-color: var(--color-accent-sage);
	color: #000;
	box-shadow: 0 0 8px rgba(122, 184, 147, 0.25);
}
.grid-cell.buffered {
	background: var(--color-accent-orange);
	border-color: var(--color-accent-orange);
	color: #000;
	animation: cell-buffered-pulse 1s infinite;
}
.grid-cell.inflight {
	background: var(--color-accent-yellow);
	border-color: var(--color-accent-yellow);
	color: #000;
}
.grid-cell.acked {
	background: var(--color-accent-green);
	border-color: var(--color-accent-green);
	color: #000;
}
.grid-cell.lost {
	background: var(--color-accent-red);
	border-color: var(--color-accent-red);
	color: #fff;
	animation: cell-lost-pulse 0.25s infinite;
}

.tcp-blocked-overlay {
	position: absolute;
	inset: 0;
	background: rgba(201, 107, 107, 0.1);
	border: 2px solid var(--color-accent-coral);
	border-radius: var(--radius-sm);
	display: none;
	align-items: center;
	justify-content: center;
	z-index: 10;
	backdrop-filter: blur(1px);
}
.tcp-blocked-overlay.active {
	display: flex;
}
.tcp-blocked-overlay span {
	background: var(--color-accent-coral);
	color: #fff;
	padding: 6px 12px;
	border-radius: var(--radius-sm);
	font-family: var(--font-mono);
	font-size: 0.7rem;
	font-weight: 700;
	text-transform: uppercase;
	animation: blocked-pulse 0.5s infinite;
}

.buffer-section {
	background: rgba(0, 0, 0, 0.3);
	border: 1px solid var(--color-border-dim);
	border-radius: var(--radius-md);
	padding: var(--space-sm);
	margin-block-start: auto;
	position: relative;
	overflow: hidden;
}
.buffer-title {
	font-family: var(--font-mono);
	font-size: 0.6rem;
	color: var(--color-text-dim);
	text-transform: uppercase;
	margin-block-end: var(--space-sm);
	display: flex;
	justify-content: space-between;
}
.buffer-count {
	color: var(--color-accent-orange);
}
.buffer-visual {
	min-height: 28px;
	display: flex;
	flex-wrap: wrap;
	gap: 3px;
}
.buffer-chip {
	width: 22px;
	height: 22px;
	border-radius: var(--radius-sm);
	font-family: var(--font-mono);
	font-size: 0.6rem;
	display: flex;
	align-items: center;
	justify-content: center;
	color: #000;
	font-weight: 600;
}
.buffer-section.blocked {
	border-color: var(--color-accent-coral);
	box-shadow: 0 0 12px rgba(201, 107, 107, 0.2);
}
.buffer-section.blocked .buffer-title {
	color: var(--color-accent-coral);
}

.canvas-container {
	position: relative;
	background: linear-gradient(180deg, rgba(0, 0, 0, 0.2) 0%, transparent 100%);
}
.protocol-badge {
	position: absolute;
	top: var(--space-sm);
	left: 50%;
	transform: translateX(-50%);
	background: rgba(0, 0, 0, 0.85);
	border: 1px solid var(--row-accent);
	padding: 6px var(--space-md);
	border-radius: var(--radius-full);
	font-family: var(--font-mono);
	font-size: 0.7rem;
	color: var(--row-accent);
	letter-spacing: 0.08em;
	z-index: 10;
}
canvas {
	width: 100%;
	height: 280px;
	display: block;
}
.status-bar {
	position: absolute;
	bottom: 0;
	left: 0;
	right: 0;
	height: 32px;
	background: rgba(0, 0, 0, 0.85);
	border-block-start: 1px solid var(--color-border-dim);
	display: flex;
	align-items: center;
	padding-inline: var(--space-md);
	font-family: var(--font-mono);
	font-size: 0.75rem;
	color: var(--color-text-dim);
}
.status-bar.good {
	color: var(--color-accent-green);
}
.status-bar.warn {
	color: var(--color-accent-yellow);
}
.status-bar.error {
	color: var(--color-accent-red);
}
.explanation {
	position: absolute;
	bottom: 44px;
	left: 50%;
	transform: translateX(-50%);
	background: rgba(0, 0, 0, 0.95);
	border: 1px solid var(--color-accent-yellow);
	padding: var(--space-sm) var(--space-md);
	border-radius: var(--radius-md);
	font-size: 0.8rem;
	color: var(--color-accent-yellow);
	max-width: 360px;
	text-align: center;
	opacity: 0;
	pointer-events: none;
	transition: opacity var(--transition-fast);
	z-index: 20;
}
.explanation.visible {
	opacity: 1;
}

@keyframes quadrant-blocked {
	0%,
	100% {
		box-shadow: 0 0 8px rgba(201, 107, 107, 0.25);
	}
	50% {
		box-shadow: 0 0 16px rgba(201, 107, 107, 0.5);
	}
}
@keyframes cell-buffered-pulse {
	0%,
	100% {
		opacity: 1;
	}
	50% {
		opacity: 0.7;
	}
}
@keyframes cell-lost-pulse {
	0%,
	100% {
		transform: scale(1);
	}
	50% {
		transform: scale(0.92);
	}
}
@keyframes blocked-pulse {
	0%,
	100% {
		opacity: 1;
	}
	50% {
		opacity: 0.7;
	}
}

.legend {
	display: flex;
	flex-wrap: wrap;
	justify-content: center;
	gap: var(--space-md);
	padding: var(--space-md);
	background: var(--color-bg-panel);
	border: 1px solid var(--color-border-dim);
	border-radius: var(--radius-lg);
	margin-block-start: var(--space-md);
}
.legend-item {
	display: flex;
	align-items: center;
	gap: var(--space-sm);
	font-size: 0.8rem;
	color: var(--color-text-mid);
}
.legend-dot {
	width: 12px;
	height: 12px;
	border-radius: var(--radius-full);
}
.legend-square {
	width: 12px;
	height: 12px;
	border-radius: 2px;
}

.insight-box {
	background: rgba(255, 170, 0, 0.08);
	border: 1px solid rgba(255, 170, 0, 0.3);
	border-radius: var(--radius-md);
	padding: var(--space-md);
	margin-block-start: var(--space-md);
	text-align: center;
}
.insight-box h3 {
	color: var(--color-accent-yellow);
	font-size: 0.85rem;
	margin-block-end: var(--space-sm);
}
.insight-box p {
	color: var(--color-text-mid);
	font-size: 0.85rem;
	line-height: 1.5;
}

.edu-grid {
	display: grid;
	grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
	gap: var(--space-md);
	margin-block-start: var(--space-lg);
}
.edu-card {
	background: var(--color-bg-panel);
	border: 1px solid var(--color-border-dim);
	border-radius: var(--radius-lg);
	padding: var(--space-md);
	border-inline-start: 3px solid var(--card-accent);
}
.edu-card.h1 {
	--card-accent: var(--color-accent-cyan);
}
.edu-card.h2 {
	--card-accent: var(--color-accent-magenta);
}
.edu-card.h3 {
	--card-accent: var(--color-accent-green);
}
.edu-card h3 {
	font-size: 0.9rem;
	color: var(--card-accent);
	margin-block-end: var(--space-sm);
}
.edu-card p {
	font-size: 0.85rem;
	color: var(--color-text-mid);
	line-height: 1.55;
}

@media (max-width: 1100px) {
	.protocol-row {
		grid-template-columns: 1fr;
		grid-template-rows: auto 300px auto;
	}
	.panel-left {
		border-inline-end: none;
		border-block-end: 1px solid var(--color-border-dim);
	}
	.panel-right {
		border-inline-start: none;
		border-block-start: 1px solid var(--color-border-dim);
	}
	.controls {
		flex-direction: column;
		gap: var(--space-md);
	}
	.speed-control,
	.loss-control {
		border-inline-start: none;
		border-block-start: 1px solid var(--color-border-dim);
		padding-block-start: var(--space-sm);
		padding-inline-start: 0;
	}
	.loss-control {
		flex-direction: column;
		gap: var(--space-sm);
	}
}
@media (max-width: 600px) {
	.container {
		padding-inline: var(--space-sm);
	}
	header h1 {
		font-size: 1.25rem;
	}
	.scenario-box,
	.insight-box {
		padding: var(--space-sm);
	}
}