/* ── Shared rich-text styles (.prose + .tab-content) ──── */
.prose,
.tab-content {
	font-size: 1rem; /* 16px */
	line-height: 1.5;
	text-align: left;
	max-width: 70ch; /* Limit line length for readability */
}

.tab-content {
	padding: 1rem 0.5rem;
}

.tab-heading {
	color: var(--color-primary);
	font-size: 1.5rem; /* 24px */
	margin-top: 0;
	margin-bottom: 1rem;
}

.prose h2, .tab-content h2 {
	font-size: 1.5rem; /* 24px */
	margin-top: 3rem;
	margin-bottom: 1.5rem;
}

.prose h3, .tab-content h3 {
	font-size: 1.25rem; /* 20px */
	margin-top: 2rem;
	margin-bottom: 1rem;
}

.prose p,
.tab-content p {
	margin-bottom: 1.5rem;
}

.prose pre,
.tab-content pre {
	background: var(--color-bg-secondary);
	padding: 0.75rem;
	border-radius: var(--radius);
	overflow-x: auto;
	position: relative;
}
.tab-content ul,
.tab-content ol {
	margin-bottom: 0.75rem;
	padding-left: 1.5rem;
}
.tab-content li {
	margin-bottom: 0.25rem;
}

/* ── Two-column layout ─────────────────────────────────── */
.lesson-layout {
	display: grid;
	grid-template-columns: 3fr 2fr;
	gap: 1.5rem;
	align-items: start;
}

.lesson-content {
	overflow-y: auto;
	max-height: 90vh;
	padding-right: 0.5rem;
	-webkit-user-select: none;
	user-select: none;
	-webkit-touch-callout: none;
}

/* ── Editor area (docked mode) ──────────────────────────── */
.editor-area {
	position: sticky;
	top: 3.5rem;
	background: var(--color-bg);
	border: 1px solid var(--color-border);
	border-radius: var(--radius);
	box-shadow: 0 8px 32px rgba(0, 0, 0, 0.18);
	display: flex;
	flex-direction: column;
	overflow: hidden;
	height: 70vh;
}
.editor-area .editor-body {
	flex: 1;
	display: flex;
	flex-direction: column;
	overflow-y: auto;
	padding: 0.5rem;
	min-height: 0;
}

/* ── Single-column layout ──────────────────────────────── */
.lesson-layout.single-col {
	grid-template-columns: 1fr;
}
.lesson-content.full-width {
	max-height: none;
	padding-right: 0;
	padding-bottom: 60px;
}

/* ── Toolbar ───────────────────────────────────────────── */
.toolbar {
	display: flex;
	align-items: center;
	gap: 0.5rem;
	margin-bottom: 0.5rem;
	flex-wrap: wrap;
}
.btn-secondary {
	background: var(--color-bg-secondary);
	color: var(--color-text);
	border: 1px solid var(--color-border);
}
.btn-secondary:hover {
	background: var(--color-border);
}
.btn-run-all {
	padding: 0.3rem 0.6rem;
	font-size: 0.8rem;
}
.lang-label {
	margin-left: auto;
	font-size: 0.75rem;
	color: var(--color-text-muted);
	font-weight: 600;
	text-transform: uppercase;
}
.panel {
	margin-bottom: 0.75rem;
}
.expected-output {
	font-size: 0.8rem;
	color: var(--color-text-muted);
}
.expected-output pre {
	background: var(--color-bg-secondary);
	padding: 0.5rem;
	border-radius: var(--radius);
	margin-top: 0.5rem;
}

/* ── Floating restore button ────────────────────────────── */
.float-restore-btn {
	position: fixed;
	bottom: 1rem;
	right: 1rem;
	z-index: 9999;
	background: var(--color-primary);
	color: #fff;
	border: none;
	border-radius: var(--radius);
	padding: 0.6rem 1rem;
	font-size: 0.85rem;
	font-weight: 600;
	cursor: pointer;
	box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
	transition: background 0.15s, transform 0.1s;
}
.float-restore-btn:hover {
	background: var(--color-primary-dark);
}
.float-restore-btn:active {
	transform: scale(0.95);
}

/* ── Desktop floating mode ─────────────────────────────── */
.editor-area.floating {
	position: fixed;
	bottom: 1rem;
	right: 1rem;
	top: auto;
	width: 45vw;
	height: 70vh;
	min-width: 320px;
	max-width: 100vw;
	max-height: 100vh;
	z-index: 9999;
	background: var(--color-bg);
	border: 1px solid var(--color-border);
	border-radius: var(--radius);
	box-shadow: 0 8px 32px rgba(0, 0, 0, 0.18);
	display: flex;
	flex-direction: column;
	overflow: hidden;
}
.editor-area.floating-hidden {
	display: none !important;
}

/* ── Mobile bottom sheet ──────────────────────────────── */
.editor-area.mobile-sheet {
	position: fixed;
	top: auto;
	bottom: 0;
	left: 0;
	right: 0;
	z-index: 9999;
	background: var(--color-bg);
	border-top: 2px solid var(--color-primary);
	border-radius: 12px 12px 0 0;
	box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.15);
	display: flex;
	flex-direction: column;
	overflow-y: auto;
	overflow-x: hidden;
	transition: height 0.3s cubic-bezier(0.4, 0, 0.2, 1), border-radius 0.2s ease;
}
.editor-area.mobile-hidden {
	height: 52px;
}
.editor-area.mobile-half {
	height: 60vh;
}
.editor-area.mobile-full {
	height: 100dvh;
	border-radius: 0;
	max-height: none;
}
.mobile-sheet .editor-body {
	overscroll-behavior: contain;
}
/* ── Mobile full: expand content to fill ────────────── */
.editor-area.mobile-full .editor-body,
.editor-area.mobile-full .tab-panel:not(.tab-hidden),
.editor-area.mobile-full .panel,
.editor-area.mobile-full .circuit-container,
.editor-area.mobile-full .editor-wrapper {
	flex: 1;
	display: flex;
	flex-direction: column;
	min-height: 0;
}
.editor-area.mobile-full .circuit-wrapper {
	flex: 1;
	height: auto;
}
.editor-area.mobile-full .cm-editor {
	flex: 1;
	max-height: none;
	min-height: 0;
}
.editor-area.mobile-full .cm-scroller {
	flex: 1;
}
.editor-area.mobile-full .velxio-iframe {
	flex: 1;
	min-height: 0;
}

/* ── Tab panels ────────────────────────────────────────── */
.tab-panel {
	overflow-y: auto;
}
.tab-hidden {
	display: none;
}

/* ── Velxio (Arduino simulator) ─────────────────────── */
.storage-indicator-inline {
	display: flex;
	align-items: center;
	gap: 6px;
	font-size: 0.75rem;
	color: var(--color-text-muted);
	background: var(--color-bg-secondary);
	padding: 3px 10px;
	border-radius: 12px;
	border: 1px solid var(--color-border);
	position: absolute;
	bottom: 1rem;
	right: 1.5rem;
	z-index: 10;
	box-shadow: 0 2px 10px rgba(0, 0, 0, 0.15);
	pointer-events: none;
	opacity: 0.8;
}
.storage-indicator-inline .indicator-icon {
	line-height: 1;
	font-size: 0.8rem;
	color: var(--color-success);
}
.storage-indicator-inline .indicator-icon.saving {
	color: var(--color-primary);
	animation: pulse 1s infinite;
}
.storage-indicator-inline .indicator-text {
	font-weight: 500;
}

.velxio-panel,
.flowchart-panel,
.quiz-panel {
	display: flex;
	flex-direction: column;
	flex: 1;
	min-height: 0;
	position: relative;
	overflow: hidden;
}
.velxio-panel.tab-hidden,
.flowchart-panel.tab-hidden,
.quiz-panel.tab-hidden {
	display: none;
}
.velxio-iframe {
	flex: 1;
	width: 100%;
	min-height: 0;              /* CHANGED: was 400px — allow shrink in flex */
	border: none;
	border-radius: var(--radius);
	touch-action: pan-y;               /* allow vertical pan inside iframe */
	overscroll-behavior: contain;      /* prevent overscroll bounce */
}
@media (max-width: 768px) {
	.velxio-iframe {
		min-height: 0;    /* CHANGED: was 200px — let flex sizing work fully */
	}
	/* Ensure sheet never exceeds visual viewport when keyboard open */
	.editor-area.mobile-sheet {
		max-height: 100vh;  /* fallback for browsers without dvh */
		max-height: 100dvh; /* dynamic viewport height */
	}
	.editor-area.mobile-full {
		height: 100dvh;
		max-height: 100dvh;
	}
}
.velxio-fallback {
	padding: 2rem;
	text-align: center;
	color: var(--color-text-muted);
	background: var(--color-bg-secondary);
	border-radius: var(--radius);
	margin: 0.5rem 0;
}

/* ── Banner & Overlay styles ───────────────────────────── */
.locked-banner {
	background: #fff9db;
	border: 1px solid #fab005;
	color: #862e00;
	padding: 1rem;
	border-radius: 8px;
	margin-bottom: 2rem;
	display: flex;
	align-items: center;
	gap: 1rem;
	font-size: 0.95rem;
	line-height: 1.4;
}
.locked-banner-icon {
	font-size: 1.25rem;
	flex-shrink: 0;
	display: flex;
	align-items: center;
	justify-content: center;
	width: 2rem;
	height: 2rem;
	background: rgba(134, 46, 0, 0.1);
	border-radius: 50%;
}
.missing-list {
	font-size: 0.8rem;
	margin-top: 0.25rem;
	font-weight: 600;
}
.prereq-link {
	color: #862e00;
	text-decoration: underline;
	font-weight: 700;
}
.prereq-link:hover {
	color: #5c1e00;
}
.workspace-lock-overlay {
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	background: rgba(255, 255, 255, 0.9);
	backdrop-filter: blur(4px);
	z-index: 100;
	display: flex;
	align-items: center;
	justify-content: center;
	padding: 1.5rem;
	text-align: center;
	border-radius: inherit;
}
.lock-overlay-content {
	max-width: 280px;
}
.lock-overlay-content h3 {
	margin: 0.75rem 0 0.5rem;
	font-size: 1.1rem;
	color: var(--color-text);
}
.lock-overlay-content p {
	color: var(--color-text-muted);
	font-size: 0.85rem;
	line-height: 1.4;
}
.lock-overlay-icon {
	font-size: 2.5rem;
	line-height: 1;
	margin-bottom: 0.5rem;
	display: inline-block;
}
@media (max-width: 600px) {
	.lock-overlay-icon {
		font-size: 2rem;
	}
	.lock-overlay-content h3 {
		font-size: 1rem;
	}
}
.editor-locked {
	overflow: hidden;
}

.quiz-blur-container {
	display: flex;
	align-items: center;
	justify-content: center;
	min-height: 400px;
	background: #f1f3f5;
	border-radius: 12px;
	margin: 2rem 0;
	text-align: center;
	border: 2px dashed var(--color-border);
	position: relative;
	overflow: hidden;
}

.quiz-blur-container::before {
	content: "";
	position: absolute;
	top: 0; left: 0; right: 0; bottom: 0;
	background: linear-gradient(to bottom, #eee 20%, #ddd 20%, #ddd 40%, #eee 40%, #eee 60%, #ddd 60%, #ddd 80%, #eee 80%);
	background-size: 100% 40px;
	filter: blur(8px);
	opacity: 0.3;
}

.quiz-blur-content {
	position: relative;
	z-index: 1;
	max-width: 300px;
	background: white;
	padding: 2rem;
	border-radius: 16px;
	box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.quiz-blur-icon {
	font-size: 3rem;
	margin-bottom: 1rem;
}

.quiz-blur-content h3 {
	margin-bottom: 0.5rem;
	color: var(--color-text);
}

.quiz-blur-content p {
	font-size: 0.9rem;
	color: var(--color-text-muted);
	margin-bottom: 1.5rem;
	line-height: 1.4;
}