/* OpenPress PNG to WebP Converter interface (task 039: foundation). Loaded on the PNG to WebP Converter Free Tool page only,
   after free-tool-single.css, inside the .op-free-tool-interface frame. Uses the theme's global tokens (--op-bg-elevated,
   --op-text, --op-border, --op-link, --op-btn-bg ...) and the shared .op-btn, so light and dark follow the theme switch
   (prefers-color-scheme plus :root[data-theme]). Same visual language as the JPG to WebP Converter; the two files share no
   selectors (.op-p2w vs .op-j2w), in line with the project's one-stylesheet-per-tool rule. Only additions: error/success
   colours, a tint and a soft-surface token, each with a light and a dark value (the theme has none). Task 039C aligned
   spacing (4/8/12/16/24/32/48 scale), the upload zone, buttons, message box, success surface and motion with the JPG
   file. Presentation only: no selector, state attribute or hook used by png-to-webp-converter.js was renamed or removed. */

.op-p2w {
	--op-p2w-error: #B42318;
	--op-p2w-success: #067647;
	--op-p2w-success-fill: #16A34A;
	--op-p2w-info: var(--op-link);
	--op-p2w-tint: rgb(37 99 235 / 0.08);
	--op-p2w-tint-strong: rgb(37 99 235 / 0.14);
	--op-p2w-zone: #F1F3F5;
	--op-p2w-ease: cubic-bezier(0.2, 0, 0, 1);
	/* Transparency checkerboard: derived from theme tokens, so it follows light and dark by itself. */
	--op-p2w-checker: repeating-conic-gradient(color-mix(in srgb, var(--op-text) 8%, var(--op-bg-elevated)) 0% 25%, var(--op-bg-elevated) 0% 50%) 0 0 / 12px 12px;
	display: grid;
	gap: 1.5rem;
	min-width: 0;
}
@media (prefers-color-scheme: dark) {
	.op-p2w { --op-p2w-error: #F97066; --op-p2w-success: #47CD89; --op-p2w-success-fill: #22C55E; --op-p2w-tint: rgb(91 141 255 / 0.1); --op-p2w-tint-strong: rgb(91 141 255 / 0.18); --op-p2w-zone: #171D33; }
	:root[data-theme="light"] .op-p2w { --op-p2w-error: #B42318; --op-p2w-success: #067647; --op-p2w-success-fill: #16A34A; --op-p2w-tint: rgb(37 99 235 / 0.08); --op-p2w-tint-strong: rgb(37 99 235 / 0.14); --op-p2w-zone: #F1F3F5; }
}
:root[data-theme="dark"] .op-p2w { --op-p2w-error: #F97066; --op-p2w-success: #47CD89; --op-p2w-success-fill: #22C55E; --op-p2w-tint: rgb(91 141 255 / 0.1); --op-p2w-tint-strong: rgb(91 141 255 / 0.18); --op-p2w-zone: #171D33; }

/* Heading ----------------------------------------------------------------- */
.op-p2w__intro { display: grid; gap: 0.25rem; min-width: 0; }
.op-p2w__heading { margin: 0; color: var(--op-text); font-family: var(--op-font-display); font-size: 1.25rem; font-weight: 700; letter-spacing: -0.02em; line-height: 1.25; overflow-wrap: anywhere; }
.op-p2w__lede { margin: 0; color: var(--op-text-muted); font-size: 0.875rem; line-height: 1.4; }

/* Upload zone: empty and invalid states ------------------------------------ */
.op-p2w__zone {
	position: relative;
	display: flex;
	flex-direction: column;
	align-items: center;
	gap: 0.5rem;
	min-width: 0;
	padding: 3rem 1.5rem;
	background: var(--op-p2w-zone);
	border: 1.5px dashed var(--op-border-strong);
	border-radius: 1.25rem;
	text-align: center;
	transition: border-color 200ms var(--op-p2w-ease), background-color 200ms var(--op-p2w-ease);
}
.op-p2w__zone[hidden] { display: none; }
.op-p2w__zone:hover,
.op-p2w__zone:focus-within { border-color: var(--op-btn-bg); background: color-mix(in srgb, var(--op-btn-bg) 5%, var(--op-p2w-zone)); }
/* Drag over: clearly visible, still calm. */
.op-p2w__zone[data-dragging="true"] { border-style: solid; border-color: var(--op-btn-bg); background: var(--op-p2w-tint-strong); }
.op-p2w__zone:has(.op-p2w__input:focus-visible) { border-style: solid; border-color: var(--op-focus); }

.op-p2w__zone-icon {
	display: grid;
	place-items: center;
	width: 3.5rem;
	height: 3.5rem;
	margin-bottom: 0.75rem;
	border-radius: 50%;
	background: var(--op-p2w-tint);
	color: var(--op-link);
	transition: transform 200ms var(--op-p2w-ease), background-color 200ms var(--op-p2w-ease);
}
.op-p2w__zone:hover .op-p2w__zone-icon,
.op-p2w__zone:focus-within .op-p2w__zone-icon,
.op-p2w__zone[data-dragging="true"] .op-p2w__zone-icon { transform: translateY(-2px); background: var(--op-p2w-tint-strong); }
.op-p2w__zone-title { margin: 0; color: var(--op-text); font-size: 1.0625rem; font-weight: 600; line-height: 1.3; overflow-wrap: anywhere; }
.op-p2w__zone-or { margin: 0 0 0.75rem; color: var(--op-text-muted); font-size: 0.875rem; }

/* The real file input stays in the accessibility tree and the tab order; it is only visually hidden. */
.op-p2w__input {
	position: absolute;
	width: 1px;
	height: 1px;
	margin: 0;
	padding: 0;
	overflow: hidden;
	opacity: 0;
	clip-path: inset(50%);
	pointer-events: none;
}
.op-p2w__choose { min-width: 12rem; max-width: 100%; min-height: 3rem; padding: 0 1.5rem; border-radius: 0.75rem; font-size: 0.9375rem; font-weight: 600; cursor: pointer; }
.op-p2w__btn-icon { flex: none; transition: transform 200ms var(--op-p2w-ease); }
.op-p2w__choose:hover .op-p2w__btn-icon { transform: translateX(2px); }
.op-p2w__input:focus-visible + .op-p2w__choose { outline: 3px solid var(--op-focus); outline-offset: 3px; }
.op-p2w[data-busy="true"] .op-p2w__choose { opacity: 0.6; cursor: not-allowed; }

.op-p2w__hint { display: grid; gap: 0.25rem; justify-items: center; max-width: 100%; margin-top: 0.75rem; color: var(--op-text-muted); font-size: 0.8125rem; line-height: 1.4; }
.op-p2w__hint p { margin: 0; overflow-wrap: anywhere; }
.op-p2w__formats { color: var(--op-text); font-weight: 500; }
.op-p2w__hint .op-p2w__trust {
	display: flex;
	align-items: flex-start;
	justify-content: center;
	gap: 0.5rem;
	margin-top: 0.75rem;
	padding-top: 0.75rem;
	border-top: 1px solid var(--op-border);
	color: var(--op-text-muted);
	font-size: 0.8125rem;
	text-align: left;
}
.op-p2w__trust svg { flex: none; margin-top: 1px; color: var(--op-link); }

/* Message box: validation problems and notices. Icon + title + text, so colour is never the only signal. */
.op-p2w__message {
	display: flex;
	align-items: flex-start;
	gap: 0.75rem;
	min-width: 0;
	padding: 0.75rem 1rem;
	background: color-mix(in srgb, var(--op-p2w-error) 7%, var(--op-bg-elevated));
	border: 1px solid color-mix(in srgb, var(--op-p2w-error) 40%, var(--op-border));
	border-left-width: 4px;
	border-radius: 0.75rem;
	animation: op-p2w-in 250ms var(--op-p2w-ease) both;
}
.op-p2w__message[hidden] { display: none; }
.op-p2w__message[data-kind="info"] { background: var(--op-p2w-tint); border-color: color-mix(in srgb, var(--op-link) 35%, var(--op-border)); }
.op-p2w__message-icon { flex: none; margin-top: 1px; }
.op-p2w__message-icon--error { color: var(--op-p2w-error); }
.op-p2w__message-icon--info { display: none; color: var(--op-link); }
.op-p2w__message[data-kind="info"] .op-p2w__message-icon--error { display: none; }
.op-p2w__message[data-kind="info"] .op-p2w__message-icon--info { display: block; }
.op-p2w__message-body { display: grid; gap: 2px; min-width: 0; font-size: 0.875rem; line-height: 1.4; }
.op-p2w__message-body p { margin: 0; overflow-wrap: anywhere; }
.op-p2w__message-title { color: var(--op-p2w-error); font-weight: 600; }
.op-p2w__message[data-kind="info"] .op-p2w__message-title { color: var(--op-text); }
.op-p2w__message-name { color: var(--op-text); font-weight: 500; }
.op-p2w__message-text { color: var(--op-text); }

/* Selected-file card ------------------------------------------------------- */
.op-p2w__file { display: grid; gap: 1rem; min-width: 0; }
.op-p2w__file[hidden] { display: none; }
.op-p2w__card {
	display: grid;
	grid-template-columns: 5rem minmax(0, 1fr) auto;
	align-items: center;
	gap: 0.75rem 1rem;
	min-width: 0;
	padding: 0.75rem;
	background: var(--op-bg-elevated);
	border: 1px solid var(--op-border);
	border-radius: 1rem;
	box-shadow: var(--op-shadow-sm);
	animation: op-p2w-in 250ms var(--op-p2w-ease) both;
}
.op-p2w[data-state="error"] .op-p2w__card { border-color: color-mix(in srgb, var(--op-p2w-error) 45%, var(--op-border)); }
/* Preview: a fixed box; the image is CONTAINED (aspect ratio kept, never cropped or stretched). Light checkerboard shows transparency. */
.op-p2w__preview {
	display: grid;
	place-items: center;
	width: 5rem;
	height: 5rem;
	overflow: hidden;
	border-radius: 0.625rem;
	color: var(--op-link);
	background: var(--op-p2w-checker);
	border: 1px solid var(--op-border);
}
.op-p2w__preview img { display: block; width: 100%; height: 100%; object-fit: contain; }
.op-p2w__info { display: grid; gap: 2px; min-width: 0; }
.op-p2w__name {
	display: -webkit-box;
	-webkit-box-orient: vertical;
	-webkit-line-clamp: 2;
	line-clamp: 2;
	overflow: hidden;
	color: var(--op-text);
	font-size: 0.9375rem;
	font-weight: 600;
	line-height: 1.3;
	overflow-wrap: anywhere;
}
.op-p2w__meta { color: var(--op-text-muted); font-size: 0.8125rem; line-height: 1.4; overflow-wrap: anywhere; }
.op-p2w__status { color: var(--op-text-muted); font-size: 0.8125rem; font-weight: 500; }
.op-p2w__status[hidden] { display: none; }
/* Processing: a small spinner before the status text. Pure CSS. */
.op-p2w__status:not([hidden])::before {
	content: "";
	display: inline-block;
	width: 0.875rem;
	height: 0.875rem;
	margin-right: 0.5rem;
	vertical-align: -2px;
	border: 2px solid color-mix(in srgb, var(--op-text) 18%, transparent);
	border-top-color: var(--op-link);
	border-radius: 50%;
	animation: op-p2w-spin 800ms linear infinite;
}
.op-p2w__remove {
	display: grid;
	place-items: center;
	width: 2.75rem;
	height: 2.75rem;
	padding: 0;
	background: transparent;
	border: 1px solid transparent;
	border-radius: 0.75rem;
	color: var(--op-text-muted);
	cursor: pointer;
	transition: background-color 150ms var(--op-p2w-ease), border-color 150ms var(--op-p2w-ease), color 150ms var(--op-p2w-ease);
}
.op-p2w__remove:hover { background: color-mix(in srgb, var(--op-text) 7%, transparent); color: var(--op-text); }
.op-p2w__remove[aria-disabled="true"] { opacity: 0.45; cursor: not-allowed; }
.op-p2w__remove[aria-disabled="true"]:hover { background: transparent; color: var(--op-text-muted); }

/* Actions ------------------------------------------------------------------ */
.op-p2w__actions,
.op-p2w__result-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 0.75rem; min-width: 0; }
.op-p2w__convert { min-height: 3rem; padding: 0 1.5rem; border-radius: 0.75rem; font-size: 0.9375rem; font-weight: 600; }
.op-p2w__convert[aria-disabled="true"] { opacity: 0.55; cursor: not-allowed; pointer-events: auto; }
.op-p2w__convert[aria-disabled="true"]:hover { background: var(--op-btn-bg); }
.op-p2w__convert[aria-busy="true"] { cursor: progress; }
.op-p2w__change,
.op-p2w__result-actions .op-p2w__reset { min-height: 3rem; padding: 0 1.25rem; border-radius: 0.75rem; font-size: 0.9375rem; font-weight: 600; }
.op-p2w__change[aria-disabled="true"] { opacity: 0.5; cursor: not-allowed; pointer-events: auto; }
.op-p2w__actions .op-p2w__reset { min-height: 2.75rem; padding: 0 1rem; border-radius: 0.75rem; font-size: 0.875rem; font-weight: 600; color: var(--op-text-muted); }
.op-p2w__actions .op-p2w__reset:hover { color: var(--op-text); }
.op-p2w__note { margin: 0; color: var(--op-text-muted); font-size: 0.8125rem; line-height: 1.5; }
.op-p2w__note[hidden] { display: none; }
.op-p2w__convert:focus-visible,
.op-p2w__change:focus-visible,
.op-p2w__reset:focus-visible,
.op-p2w__remove:focus-visible { outline: 3px solid var(--op-focus); outline-offset: 2px; }

/* Result (039B, polished in 039C): the success surface, same recipe as the JPG summary card -------------- */
.op-p2w__result {
	display: grid;
	gap: 1rem;
	min-width: 0;
	padding: 1.5rem;
	background: color-mix(in srgb, var(--op-p2w-success-fill) 5%, var(--op-bg-elevated));
	border: 1px solid color-mix(in srgb, var(--op-p2w-success-fill) 30%, var(--op-border));
	border-radius: 1rem;
	animation: op-p2w-in 300ms var(--op-p2w-ease) both;
}
.op-p2w__result[hidden] { display: none; }
.op-p2w__result-title { display: flex; align-items: center; justify-self: start; max-width: 100%; gap: 0.625rem; margin: 0; color: var(--op-text); font-family: var(--op-font-display); font-size: 1.125rem; font-weight: 700; letter-spacing: -0.01em; line-height: 1.25; }
.op-p2w__result-title svg { flex: none; color: var(--op-p2w-success-fill); }
.op-p2w__result-title:focus-visible { outline: 3px solid var(--op-focus); outline-offset: 3px; border-radius: 0.25rem; }
.op-p2w__compare { display: grid; grid-template-columns: minmax(0, 1fr); gap: 0.75rem; min-width: 0; }
.op-p2w__panel { display: grid; gap: 0.75rem; align-content: start; min-width: 0; padding: 1rem; background: var(--op-p2w-zone); border: 1px solid var(--op-border); border-radius: 0.75rem; }
.op-p2w__panel-title { margin: 0; color: var(--op-text-muted); font-size: 0.75rem; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; }
.op-p2w__panel-preview {
	min-width: 0;
	padding: 0.5rem;
	border: 1px solid var(--op-border);
	border-radius: 0.625rem;
	/* Checkerboard so transparent areas of the PNG and the WebP read as transparent. */
	background: var(--op-p2w-checker);
}
.op-p2w__panel-preview img { display: block; max-width: 100%; max-height: 16rem; margin-inline: auto; object-fit: contain; }
.op-p2w__facts { display: grid; gap: 0.5rem; margin: 0; min-width: 0; }
.op-p2w__fact { display: grid; grid-template-columns: minmax(5.5rem, auto) minmax(0, 1fr); gap: 0.5rem 0.75rem; align-items: baseline; min-width: 0; }
.op-p2w__fact-label { margin: 0; color: var(--op-text-muted); font-size: 0.75rem; font-weight: 500; line-height: 1.4; }
.op-p2w__fact-value { margin: 0; color: var(--op-text); font-size: 0.9375rem; font-weight: 600; font-variant-numeric: tabular-nums; line-height: 1.4; overflow-wrap: anywhere; }

/* Honest size change: colour plus an arrow and words (colour is never the only cue). */
.op-p2w__delta { margin: 0; color: var(--op-text); font-size: 0.9375rem; font-weight: 600; line-height: 1.3; }
.op-p2w__delta:empty { display: none; }
.op-p2w__delta[data-kind="smaller"] { color: var(--op-p2w-success); }
.op-p2w__delta[data-kind="smaller"]::before { content: "\2193\00a0"; }
.op-p2w__delta[data-kind="larger"]::before { content: "\2191\00a0"; color: var(--op-text-muted); }

/* Download: the shared primary button; a Download icon is added in CSS only. */
.op-p2w__download { min-height: 3rem; padding: 0 1.5rem; border-radius: 0.75rem; font-size: 0.9375rem; font-weight: 600; text-decoration: none; max-width: 100%; }
.op-p2w__download::before {
	content: "";
	flex: none;
	width: 1.125rem;
	height: 1.125rem;
	background: currentColor;
	-webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M12 15V3'/%3E%3Cpath d='M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4'/%3E%3Cpath d='m7 10 5 5 5-5'/%3E%3C/svg%3E") center / contain no-repeat;
	mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M12 15V3'/%3E%3Cpath d='M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4'/%3E%3Cpath d='m7 10 5 5 5-5'/%3E%3C/svg%3E") center / contain no-repeat;
}
.op-p2w__download:focus-visible { outline: 3px solid var(--op-focus); outline-offset: 3px; }
.op-p2w__facts:empty,
.op-p2w__panel-preview:empty,
.op-p2w__download-slot:empty { display: none; }
.op-p2w__download-slot { min-width: 0; }

/* Motion ---------------------------------------------------------------- */
@keyframes op-p2w-in { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
@keyframes op-p2w-spin { to { transform: rotate(360deg); } }

/* Responsive ------------------------------------------------------------ */
@media (max-width: 767px) {
	.op-p2w__zone { padding: 2rem 1rem; }
}
@media (min-width: 768px) {
	.op-p2w__zone { padding: 3.5rem 2rem; }
	.op-p2w__compare { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 480px) {
	.op-p2w__choose,
	.op-p2w__convert,
	.op-p2w__change,
	.op-p2w__result-actions .op-p2w__reset,
	.op-p2w__result-actions .op-btn,
	.op-p2w__download-slot { width: 100%; }
	.op-p2w__actions .op-p2w__reset { width: 100%; }
	.op-p2w__card { grid-template-columns: 4rem minmax(0, 1fr) auto; gap: 0.5rem 0.75rem; }
	.op-p2w__preview { width: 4rem; height: 4rem; }
	.op-p2w__result { padding: 1rem; }
	.op-p2w__fact { grid-template-columns: 1fr; gap: 0; }
}

/* Reduced motion: no entrance animation, no hover movement, spinner becomes a static ring. */
@media (prefers-reduced-motion: reduce) {
	.op-p2w *,
	.op-p2w *::before { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
	.op-p2w__zone:hover .op-p2w__zone-icon,
	.op-p2w__zone:focus-within .op-p2w__zone-icon,
	.op-p2w__zone[data-dragging="true"] .op-p2w__zone-icon,
	.op-p2w__choose:hover .op-p2w__btn-icon { transform: none; }
}