/* ============================================================
   CUSTOM PROPERTIES (colours & typography)
   ============================================================ */
:root {
	/* ----- Fonts ----- */
	--font-master-scale: 1.1;
	--font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
	--font-size-base: calc(0.8rem * var(--font-master-scale));
	--font-size-small:  calc(0.72rem * var(--font-master-scale));
	--font-size-xs:  calc(0.7rem * var(--font-master-scale));
	--font-size-medium:  calc(0.95rem * var(--font-master-scale));
	--font-size-large:  calc(1.1rem * var(--font-master-scale));
	--font-weight-normal:  calc(400 * var(--font-master-scale));
	--font-weight-medium:  calc(500 * var(--font-master-scale));
	--font-weight-semibold:  calc(600 * var(--font-master-scale));

	/* ----- Colours ----- */
	--color-bg-body: #f2f4f8;
	--color-bg-app: #f8fafc;
	--color-bg-surface: #ffffff;
	--color-text-primary: #1e1e2a;
	--color-text-secondary: #2a2a3a;
	--color-text-muted: rgba(0, 0, 0, 0.35);
	--color-border-light: rgba(0, 0, 0, 0.06);
	--color-border-medium: rgba(0, 0, 0, 0.1);
	--color-accent: #f2c05e;
	--color-accent-hover: #fbd487;
	--color-bg-input: rgba(255, 255, 255, 0.8);
	--color-bg-input-focus: #ffffff;
	--color-bg-button: rgba(0, 0, 0, 0.04);
	--color-bg-button-hover: rgba(0, 0, 0, 0.08);
	--color-bg-section: rgba(0, 0, 0, 0.02);
	--color-shadow: rgba(0, 0, 0, 0.15);
	--color-shadow-light: rgba(0, 0, 0, 0.08);
	--color-delete: rgba(200, 40, 40, 0.85);
	--color-progress-start: #2a5bd7;
	--color-progress-end: #6c8cff;
	--color-scrollbar-handle: rgba(0, 0, 0, .5);

	/* ----- constants that need to match in mandelbrot.js ----- */
	--thumbnail-size: 96px;
}

/* ---------- Reset & Base ---------- */
*,
*::before,
*::after {
	box-sizing: border-box;
	margin: 0;
	padding: 0;
}
html {
	height: 100%;
	overflow: hidden;
}
body {
	height: 100%;
	font-family: var(--font-family-base);
	background: var(--color-bg-body);
	color: var(--color-text-primary);
	display: flex;
	justify-content: center;
	align-items: center;
	overflow: hidden;
}
@supports (font-variation-settings: normal) {
	body {
		font-family: 'Inter var', sans-serif;
	}
}

/* ---------- App Shell ---------- */
.app {
	display: flex;
	flex-direction: column;
	width: 100vw;
	height: 100vh;
	max-width: 100%;
	background: var(--color-bg-app);
	overflow: hidden;
}

/* ---------- Top Bar ---------- */
.topbar {
	display: flex;
	align-items: center;
	justify-content: space-between;
	padding: 0.4rem 1rem;
	background: rgba(255, 255, 255, 0.85);
	backdrop-filter: blur(12px);
	-webkit-backdrop-filter: blur(12px);
	border-bottom: 1px solid var(--color-border-light);
	flex-shrink: 0;
	z-index: 10;
	min-height: 48px;
	flex-wrap: wrap;
	gap: 0.3rem;
}
.topbar .brand {
	display: flex;
	align-items: center;
	gap: 0.5rem;
	font-weight: var(--font-weight-semibold);
	font-size: var(--font-size-medium);
	letter-spacing: -0.01em;
	color: var(--color-text-primary);
}
.topbar .brand svg {
	width: 24px;
	height: 24px;
	fill: none;
	stroke: var(--color-accent);
	stroke-width: 2;
}
.topbar .brand small {
	font-weight: var(--font-weight-normal);
	font-size: var(--font-size-small);
	color: var(--color-text-muted);
	margin-left: 0.1rem;
}
.topbar .actions {
	display: flex;
	align-items: center;
	gap: 0.3rem;
	flex-wrap: wrap;
}
.topbar .actions .btn {
	background: var(--color-bg-button);
	border: none;
	color: var(--color-text-secondary);
	padding: 0.25rem 0.7rem;
	border-radius: 6px;
	font-size: var(--font-size-small);
	font-weight: var(--font-weight-medium);
	cursor: pointer;
	transition: background 0.2s, color 0.2s, transform 0.1s;
	display: inline-flex;
	align-items: center;
	gap: 0.25rem;
	white-space: nowrap;
}
.topbar .actions .btn:hover {
	background: var(--color-bg-button-hover);
	color: #000;
}
.topbar .actions .btn:active {
	transform: scale(0.96);
}
.topbar .actions .btn-primary {
	background: var(--color-accent);
	color: #000;
	text-decoration:none;
}
.topbar .actions .btn-primary:hover {
	color: #200;
	background: var(--color-accent-hover);
}
.topbar .actions .btn-icon {
	padding: 0.25rem 0.5rem;
	font-size: 1rem;
	line-height: 1;
}

/* ---------- Main Layout ---------- */
.main {
	display: flex;
	flex: 1 1 auto;
	min-height: 0;
	position: relative;
}

/* ---------- Canvas Area ---------- */
.canvas-area {
	flex: 1 1 auto;
	min-width: 0;
	min-height: 0;
	position: relative;
	background: var(--color-bg-surface);
	display: flex;
	align-items: center;
	justify-content: center;
	overflow: hidden;
}
.canvas-area canvas {
	display: block;
	width: 100%;
	height: 100%;
	object-fit: contain;
	background: var(--color-bg-surface);
	image-rendering: pixelated;
}
.canvas-area::after {
	content: '';
	position: absolute;
	inset: 0;
	pointer-events: none;
	background: radial-gradient(ellipse at center, transparent 60%, rgba(0, 0, 0, 0.04) 100%);
	z-index: 2;
}

/* ---------- Right Sidebar ---------- */
.sidebar {
	width: 340px;
	max-width: 40vw;
	background: rgba(255, 255, 255, 0.92);
	backdrop-filter: blur(16px);
	-webkit-backdrop-filter: blur(16px);
	border-left: 1px solid var(--color-border-light);
	display: flex;
	flex-direction: column;
	flex-shrink: 0;
	overflow: hidden;
	transition: width 0.3s ease, max-width 0.3s ease;
}
.sidebar.collapsed {
	width: 0;
	max-width: 0;
	border-left: none;
}

.sidebar-scroll {
	flex: 1 1 auto;
	overflow-y: auto;
	padding: 0.6rem 0.8rem 1.2rem;
	scrollbar-width: thin;
	scrollbar-color: var(--color-scrollbar-handle) transparent;
}
.sidebar-scroll::-webkit-scrollbar {
	width: 4px;
}
.sidebar-scroll::-webkit-scrollbar-track {
	background: transparent;
}
.sidebar-scroll::-webkit-scrollbar-thumb {
	background: var(--color-scrollbar-handle);
	border-radius: 8px;
}

/* ---------- Sidebar Sections ---------- */
.section {
	margin-bottom: 1rem;
	background: var(--color-bg-section);
	border-radius: 10px;
	border: 1px solid var(--color-border-light);
	overflow: hidden;
}
.section-header {
	display: flex;
	align-items: center;
	justify-content: space-between;
	padding: 0.45rem 0.8rem;
	font-weight: var(--font-weight-semibold);
	font-size: var(--font-size-small);
	text-transform: uppercase;
	letter-spacing: 0.04em;
	color: rgba(0, 0, 0, 0.45);
	cursor: pointer;
	user-select: none;
	transition: background 0.15s;
	border-bottom: 1px solid var(--color-border-light);
}
.section-header:hover {
	background: rgba(0, 0, 0, 0.02);
}
.section-header .chevron {
	transition: transform 0.25s ease;
	font-size: var(--font-size-xs);
	opacity: 0.5;
}
.section-header.collapsed .chevron {
	transform: rotate(-90deg);
}
.section-body {
	padding: 0.6rem 0.8rem 0.8rem;
	overflow: hidden;
	transition: max-height 0.3s ease, opacity 0.25s ease, padding 0.3s ease;
	max-height: 0;
	opacity: 0;
	padding-top: 0;
	padding-bottom: 0;
}
.section-body.open {
	max-height: 2000px;
	opacity: 1;
	padding-top: 0.6rem;
	padding-bottom: 0.8rem;
}

/* ---------- Form Elements ---------- */
.field-row {
	display: flex;
	align-items: center;
	gap: 0.5rem;
	margin-bottom: 0.35rem;
	font-size: var(--font-size-base);
	color: rgba(0, 0, 0, 0.7);
}
.field-row label {
	flex: 0 0 auto;
	min-width: 4.5rem;
	font-weight: 450;
}
.field-row input[type="number"],
.field-row input[type="text"],
.field-row select {
	flex: 1 1 auto;
	min-width: 0;
	background: var(--color-bg-input);
	border: 1px solid var(--color-border-medium);
	border-radius: 6px;
	padding: 0.2rem 0.5rem;
	color: var(--color-text-primary);
	font-size: var(--font-size-base);
	font-family: inherit;
	transition: border 0.2s, background 0.2s;
	width: 100%;
}
.field-row input[type="number"]:focus,
.field-row input[type="text"]:focus,
.field-row select:focus {
	outline: none;
	border-color: var(--color-accent);
	background: var(--color-bg-input-focus);
}
.field-row input[type="number"] {
	-moz-appearance: textfield;
}
/*
.field-row input[type="number"]::-webkit-outer-spin-button,
.field-row input[type="number"]::-webkit-inner-spin-button {
	-webkit-appearance: none;
	margin: 0;
}
*/
.field-row .multiplier-btn {
	flex: 0 0 auto;
	background: var(--color-bg-button);
	border: none;
	border-radius: 4px;
	padding: 0.1rem 0.5rem;
	font-size: var(--font-size-xs);
	font-weight: var(--font-weight-semibold);
	color: rgba(0, 0, 0, 0.5);
	cursor: pointer;
	transition: background 0.15s, color 0.15s;
}
.field-row .multiplier-btn:hover {
	background: var(--color-bg-button-hover);
	color: #000;
}
.field-row .inline-group {
	display: flex;
	align-items: center;
	gap: 0.3rem;
	flex: 1 1 auto;
}
.field-row .inline-group input {
	flex: 1 1 auto;
	min-width: 0;
}

/* coefficient input style */
.coeff-input {
	width: 2.5rem;
	margin-left: auto;
	background: rgba(255, 255, 255, 0.6);
	border: 1px solid var(--color-border-light);
	border-radius: 4px;
	padding: 0.1rem 0.2rem;
	color: var(--color-text-primary);
	font-size: var(--font-size-xs);
	text-align: center;
}

/* checkboxes & radios */
.check-group {
	display: flex;
	align-items: center;
	gap: 0.4rem;
	font-size: var(--font-size-small);
	color: rgba(0, 0, 0, 0.75);
	cursor: pointer;
	padding: 0.1rem 0;
}
.check-group input[type="checkbox"],
.check-group input[type="radio"] {
	appearance: none;
	-webkit-appearance: none;
	width: 16px;
	height: 16px;
	border: 1.5px solid rgba(0, 0, 0, 0.2);
	border-radius: 4px;
	background: var(--color-bg-surface);
	flex-shrink: 0;
	cursor: pointer;
	transition: background 0.2s, border-color 0.2s;
	position: relative;
}
.check-group input[type="checkbox"]:checked {
	background: var(--color-accent);
	border-color: var(--color-accent);
}
.check-group input[type="checkbox"]:checked::after {
	content: '✓';
	position: absolute;
	inset: 0;
	display: flex;
	align-items: center;
	justify-content: center;
	font-size: 12px;
	color: #fff;
	line-height: 1;
}
.check-group input[type="radio"] {
	border-radius: 50%;
}
.check-group input[type="radio"]:checked {
	background: var(--color-accent);
	border-color: var(--color-accent);
}
.check-group input[type="radio"]:checked::after {
	content: '';
	position: absolute;
	inset: 4px;
	border-radius: 50%;
	background: #fff;
}

.check-grid {
	display: grid;
	grid-template-columns: 1fr 1fr;
	gap: 0.1rem 0.5rem;
}
.check-grid .check-group {
	padding: 0.05rem 0;
}

/* Place left-column items in column 1, rows 1–3 */
.check-grid .col-left:nth-of-type(1) { grid-column: 1; grid-row: 1; }
.check-grid .col-left:nth-of-type(2) { grid-column: 1; grid-row: 2; }
.check-grid .col-left:nth-of-type(3) { grid-column: 1; grid-row: 3; }

/* Place right-column items in column 2, rows 1–2 */
.check-grid .col-right:nth-of-type(1) { grid-column: 2; grid-row: 1; }
.check-grid .col-right:nth-of-type(2) { grid-column: 2; grid-row: 2; }

/* ---------- Sliders (colour) ---------- */
.slider-row {
	display: flex;
	align-items: center;
	gap: 0.5rem;
	margin-bottom: 0.2rem;
	font-size: var(--font-size-small);
	color: rgba(0, 0, 0, 0.6);
}
.slider-row label {
	flex: 0 0 3.2rem;
	font-weight: 450;
}
.slider-row input[type="range"] {
	flex: 1 1 auto;
	min-width: 0;
	height: 4px;
	-webkit-appearance: none;
	appearance: none;
	background: rgba(0, 0, 0, 0.12);
	border-radius: 8px;
	outline: none;
	transition: background 0.2s;
}
.slider-row input[type="range"]::-webkit-slider-thumb {
	-webkit-appearance: none;
	appearance: none;
	width: 14px;
	height: 14px;
	border-radius: 50%;
	background: var(--color-accent);
	cursor: pointer;
	border: 2px solid rgba(255, 255, 255, 0.6);
	box-shadow: 0 1px 4px var(--color-shadow-light);
	transition: transform 0.15s;
}
.slider-row input[type="range"]::-webkit-slider-thumb:hover {
	transform: scale(1.15);
}
.slider-row input[type="range"]::-moz-range-thumb {
	width: 14px;
	height: 14px;
	border-radius: 50%;
	background: var(--color-accent);
	cursor: pointer;
	border: 2px solid rgba(255, 255, 255, 0.6);
}
.slider-row .slider-val {
	width: 3rem;
	flex: 0 0 3rem;
	text-align: right;
	background: rgba(255, 255, 255, 0.6);
	border: 1px solid var(--color-border-light);
	border-radius: 4px;
	padding: 0.05rem 0.3rem;
	font-size: var(--font-size-xs);
	font-family: monospace;
	color: var(--color-text-primary);
}

/* ---------- Custom value-adjuster widgets (valueAdjuster.js) ---------- */
.field-row > .value-adjuster,
.slider-row > .value-adjuster {
	flex: 1 1 auto;
	min-width: 0;
	height: 1.5em;
}

/* The editable read-out sitting beside each widget. Needs to out-specify
   the generic `.field-row input[type="number"]` rule above, which is why
   these selectors are quite specific and appear later in the file.
   `pointer-events: auto` is important: the widget's own internal readout
   (.value-adjuster-display, a plain <div>) sets `pointer-events: none`, and
   that rule also matches this input - without this override the field can
   only be focused by tabbing, which is why clicking it previously felt so
   unresponsive. */
.field-row > input.value-adjuster-display,
.slider-row > input.value-adjuster-display {
	flex: 0 0 auto;
	width: 5.4rem;
	min-width: 0;
	min-height: 1.5em;
	text-align: right;
	background: rgba(255, 255, 255, 0.6);
	border: 1px solid var(--color-border-light);
	border-radius: 4px;
	padding: 0.2rem 0.4rem;
	font-size: var(--font-size-xs);
	font-family: monospace;
	color: var(--color-text-primary);
	-moz-appearance: textfield;
	pointer-events: auto;
	cursor: text;
}
.slider-row > input.value-adjuster-display {
	width: 4.6rem;
}
.field-row > input.value-adjuster-display:focus,
.slider-row > input.value-adjuster-display:focus {
	outline: none;
	border-color: var(--color-accent);
	background: var(--color-bg-input-focus);
}

/* ---------- Buttons ---------- */
.btn-block {
	display: flex;
	flex-wrap: wrap;
	gap: 0.3rem;
	margin-top: 0.3rem;
}
.btn-block .btn {
	flex: 1 1 auto;
	min-width: 4rem;
	background: var(--color-bg-button);
	border: 1px solid var(--color-border-light);
	border-radius: 6px;
	padding: 0.25rem 0.5rem;
	font-size: var(--font-size-small);
	font-weight: var(--font-weight-medium);
	color: var(--color-text-primary);
	cursor: pointer;
	transition: background 0.2s, color 0.2s, transform 0.1s;
	text-align: center;
	text-decoration: none;
}
.btn-block .btn:hover {
	background: var(--color-bg-button-hover);
	color: #000;
}
.btn-block .btn:active {
	transform: scale(0.96);
}
.btn-block .btn-primary {
	background: var(--color-accent);
	border-color: var(--color-accent);
	color: #fff;
}
.btn-block .btn-primary:hover {
	background: var(--color-accent-hover);
	border-color: var(--color-accent-hover);
}

/* ---------- Palette wave preview ---------- */
.palette-graph {
	/* roughly 1cm tall, as requested - uses rem so it tracks the base font */
	height: 2.4rem;
	margin: 0.35rem 0 0.1rem;
	background: rgba(0, 0, 0, 0.03);
	border: 1px solid var(--color-border-light);
	border-radius: 6px;
	overflow: hidden;
}
.palette-graph canvas {
	display: block;
	width: 100%;
	height: 100%;
}

/* ---------- Tabs (modifiers / palette) ---------- */
.tab-bar {
	display: flex;
	gap: 0.1rem;
	margin-bottom: 0.4rem;
	border-bottom: 1px solid var(--color-border-light);
	padding-bottom: 0.1rem;
}
.tab-bar .tab-btn {
	background: transparent;
	border: none;
	padding: 0.25rem 0.6rem;
	font-size: var(--font-size-xs);
	font-weight: var(--font-weight-medium);
	color: rgba(0, 0, 0, 0.4);
	cursor: pointer;
	border-radius: 6px 6px 0 0;
	transition: color 0.2s, background 0.2s;
	font-family: inherit;
}
.tab-bar .tab-btn:hover {
	color: rgba(0, 0, 0, 0.7);
	background: rgba(0, 0, 0, 0.03);
}
.tab-bar .tab-btn.active {
	color: var(--color-text-primary);
	background: rgba(0, 0, 0, 0.04);
}
.tab-pane {
	display: none;
	padding-top: 0.2rem;
}
.tab-pane.active {
	display: block;
}

/* ---------- Footer (thumbnails) ---------- */
.footer {
	flex-shrink: 0;
	background: rgba(255, 255, 255, 0.85);
	backdrop-filter: blur(10px);
	-webkit-backdrop-filter: blur(10px);
	border-top: 1px solid var(--color-border-light);
	padding: 0.3rem 0.6rem 0.45rem;
	overflow: hidden;
	max-height: 142px;
	transition: max-height 0.3s ease;
}
.footer.collapsed {
	max-height: 0;
	padding: 0 0.6rem;
	border-top: none;
}
.footer .footer-tabs {
	display: flex;
	gap: 0.2rem;
	margin-bottom: 0.2rem;
}
.footer .footer-tabs .tab-btn {
	background: transparent;
	border: none;
	padding: 0.1rem 0.5rem;
	font-size: var(--font-size-xs);
	font-weight: var(--font-weight-medium);
	color: rgba(0, 0, 0, 0.35);
	cursor: pointer;
	border-radius: 4px;
	transition: color 0.2s, background 0.2s;
	font-family: inherit;
}
.footer .footer-tabs .tab-btn:hover {
	color: rgba(0, 0, 0, 0.6);
}
.footer .footer-tabs .tab-btn.active {
	color: var(--color-text-primary);
	background: rgba(0, 0, 0, 0.04);
}

.footer .thumb-strip {
	height: calc(var(--thumbnail-size) + 0.15rem + 0.25rem); /* 96px + padding totals */
	box-sizing: border-box;
	display: flex;
	gap: 0.3rem;
	overflow-x: auto;
	overflow-y: hidden; /* prevent vertical scrollbar interference */
	padding: 0.15rem 0 0.25rem;
	scrollbar-width: thin;
	scrollbar-color: var(--color-scrollbar-handle) transparent;
}

.footer .thumb-strip::-webkit-scrollbar {
	height: 3px;
}
.footer .thumb-strip::-webkit-scrollbar-track {
	background: transparent;
}
.footer .thumb-strip::-webkit-scrollbar-thumb {
	background: var(--color-scrollbar-handle);
	border-radius: 8px;
}
.footer .thumb-strip .thumb {
	flex: 0 0 auto;
	width: 96px;
	height: 96px;
	border-radius: 6px;
	overflow: hidden;
	cursor: pointer;
	border: 2px solid transparent;
	transition: border-color 0.2s, transform 0.15s;
	background: rgba(0, 0, 0, 0.04);
	position: relative;
}
.footer .thumb-strip .thumb:hover {
	border-color: var(--color-accent);
	transform: scale(1.04);
}
.footer .thumb-strip .thumb img,
.footer .thumb-strip .thumb canvas {
	width: 100%;
	height: 100%;
	object-fit: cover;
	display: block;
}
.footer .thumb-strip .thumb .delete-icon {
	position: absolute;
	top: 2px;
	right: 2px;
	width: 18px;
	height: 18px;
	border-radius: 50%;
	background: var(--color-delete);
	color: #fff;
	font-size: 11px;
	font-weight: 700;
	display: flex;
	align-items: center;
	justify-content: center;
	cursor: pointer;
	opacity: 0;
	transition: opacity 0.2s;
	border: none;
	line-height: 1;
}
.footer .thumb-strip .thumb:hover .delete-icon {
	opacity: 1;
}

/* ---------- Popup ---------- */
.popup-overlay {
	position: fixed;
	inset: 0;
	background: rgba(0, 0, 0, 0.3);
	backdrop-filter: blur(4px);
	-webkit-backdrop-filter: blur(4px);
	display: none;
	align-items: center;
	justify-content: center;
	z-index: 1000;
	padding: 1.5rem;
}
.popup-overlay.open {
	display: flex;
}
.popup-box {
	background: var(--color-bg-surface);
	border-radius: 16px;
	max-width: 600px;
	width: 100%;
	max-height: 90vh;
	overflow-y: auto;
	padding: 1.5rem 1.8rem 1.2rem;
	border: 1px solid var(--color-border-light);
	box-shadow: 0 24px 80px var(--color-shadow);
	position: relative;
}
.popup-box h2 {
	font-size: var(--font-size-large);
	font-weight: var(--font-weight-semibold);
	margin-bottom: 0.6rem;
	color: var(--color-text-primary);
	border-bottom: 1px solid var(--color-border-light);
	padding-bottom: 0.4rem;
}
.popup-box p,
.popup-box li {
	font-size: var(--font-size-base);
	line-height: 1.6;
	color: rgba(0, 0, 0, 0.75);
}
.popup-box ul {
	padding-left: 1.2rem;
	margin: 0.4rem 0;
}
.popup-box code {
	display: block;
	background: rgba(0, 0, 0, 0.04);
	padding: 0.4rem 0.6rem;
	border-radius: 6px;
	font-size: var(--font-size-small);
	color: var(--color-text-primary);
	overflow-x: auto;
	font-family: 'JetBrains Mono', monospace;
	margin: 0.4rem 0;
	border: 1px solid var(--color-border-light);
}
.popup-box .popup-actions {
	display: flex;
	gap: 0.4rem;
	margin-top: 1rem;
	flex-wrap: wrap;
	justify-content: flex-end;
}
.popup-box .popup-actions .btn {
	background: var(--color-bg-button);
	border: none;
	border-radius: 6px;
	padding: 0.35rem 1rem;
	font-size: var(--font-size-base);
	font-weight: var(--font-weight-medium);
	color: var(--color-text-primary);
	cursor: pointer;
	transition: background 0.2s, color 0.2s;
	font-family: inherit;
}
.popup-box .popup-actions .btn:hover {
	background: var(--color-bg-button-hover);
}
.popup-box .popup-actions .btn-primary {
	background: var(--color-accent);
	color: #fff;
}
.popup-box .popup-actions .btn-primary:hover {
	background: var(--color-accent-hover);
}
.popup-box textarea {
	width: 100%;
	min-height: 80px;
	background: var(--color-bg-input);
	border: 1px solid var(--color-border-medium);
	border-radius: 6px;
	padding: 0.4rem;
	color: var(--color-text-primary);
	font-size: var(--font-size-base);
	font-family: 'JetBrains Mono', monospace;
	resize: vertical;
}
.popup-box textarea:focus {
	outline: none;
	border-color: var(--color-accent);
}

/* ---------- Responsive ---------- */
@media (max-width: 820px) {
	.sidebar {
		width: 280px;
		max-width: 45vw;
	}
	.topbar .brand small {
		display: none;
	}
	.topbar .actions .btn span {
		display: none;
	}
}
@media (max-width: 600px) {
	.sidebar {
		width: 100%;
		max-width: 100%;
		max-height: 60vh;
		border-left: none;
		border-top: 1px solid var(--color-border-light);
		position: absolute;
		bottom: 0;
		left: 0;
		right: 0;
		background: rgba(255, 255, 255, 0.95);
		backdrop-filter: blur(20px);
		-webkit-backdrop-filter: blur(20px);
		border-radius: 16px 16px 0 0;
		transform: translateY(calc(100% - 44px));
		transition: transform 0.35s cubic-bezier(0.32, 0.72, 0, 1);
		z-index: 20;
	}
	.sidebar.open {
		transform: translateY(0);
	}
	.sidebar .sidebar-scroll {
		padding: 0.4rem 0.6rem 1rem;
	}
	.sidebar .section-body {
		padding: 0.4rem 0.5rem 0.6rem;
	}
	.footer {
		max-height: 80px;
	}
	.footer .thumb-strip .thumb {
		width: 52px;
		height: 52px;
	}
	.popup-box {
		padding: 1rem 1rem 0.8rem;
		margin: 0.3rem;
	}
	.topbar {
		padding: 0.25rem 0.6rem;
		min-height: 40px;
	}
	.topbar .brand {
		font-size: var(--font-size-base);
	}
	.topbar .brand svg {
		width: 20px;
		height: 20px;
	}
	.field-row {
		font-size: var(--font-size-small);
	}
	.field-row label {
		min-width: 3.5rem;
	}
	.slider-row {
		font-size: var(--font-size-xs);
	}
	.slider-row label {
		min-width: 2.8rem;
	}
	.check-group {
		font-size: var(--font-size-xs);
	}
	.check-grid {
		grid-template-columns: 1fr;
	}
}

/* ---------- Misc Utilities ---------- */
.text-muted {
	color: var(--color-text-muted);
}
.mt-1 {
	margin-top: 0.3rem;
}
.gap-1 {
	gap: 0.3rem;
}
.flex {
	display: flex;
}
.flex-wrap {
	flex-wrap: wrap;
}
.items-center {
	align-items: center;
}
.w-full {
	width: 100%;
}

.info-button {
	display: none;
}

/* progress bar for downloads */
.progress-wrap {
	position: fixed;
	bottom: 1.5rem;
	left: 50%;
	transform: translateX(-50%);
	background: rgba(255, 255, 255, 0.92);
	backdrop-filter: blur(12px);
	-webkit-backdrop-filter: blur(12px);
	padding: 0.4rem 1rem;
	border-radius: 40px;
	border: 1px solid var(--color-border-light);
	display: flex;
	align-items: center;
	gap: 0.6rem;
	z-index: 500;
	font-size: var(--font-size-small);
	color: rgba(0, 0, 0, 0.7);
	box-shadow: 0 8px 32px var(--color-shadow-light);
	min-width: 180px;
}
.progress-wrap .bar {
	flex: 1 1 auto;
	height: 4px;
	background: rgba(0, 0, 0, 0.08);
	border-radius: 8px;
	overflow: hidden;
	min-width: 50px;
}
.progress-wrap .bar .fill {
	height: 100%;
	width: 0%;
	background: linear-gradient(90deg, var(--color-progress-start), var(--color-progress-end));
	border-radius: 8px;
	transition: width 0.2s;
}
.progress-wrap .cancel-btn {
	background: none;
	border: none;
	color: rgba(0, 0, 0, 0.3);
	cursor: pointer;
	font-size: 0.9rem;
	padding: 0 0.1rem;
	transition: color 0.2s;
}
.progress-wrap .cancel-btn:hover {
	color: #c0392b;
}

/* download preview canvas */
.preview-wrapper {
	text-align: center;
	min-height: 100px;
	position: relative;
	margin: 0.4rem 0;
}
.preview-wrapper canvas {
	border-radius: 8px;
	border: 1px solid var(--color-border-light);
	max-width: 100%;
	height: auto;
}
.download-form .field-row {
	margin-bottom: 0.25rem;
}
.download-form .field-row label {
	min-width: 4rem;
}