* {
	box-sizing: border-box;
}

body {
	min-height: 100vh;
	margin: 0;
	padding: 0;
	font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
	color: var(--text-primary);
	background: var(--page-background);
	transition: color 180ms ease, background 300ms ease;
}

button,
select,
textarea {
	font: inherit;
}

.container {
	position: relative;
	isolation: isolate;
	width: min(820px, calc(100% - 2rem));
	margin: clamp(2rem, 5vw, 4rem) auto;
	padding: 26px;
	display: grid;
	gap: 20px;
	border: 1px solid var(--container-border);
	border-radius: 28px;
	background: var(--container-background);
	box-shadow: var(--container-shadow);
	backdrop-filter: blur(20px);
	-webkit-backdrop-filter: blur(20px);
	overflow: hidden;
}

.container::before {
	content: "";
	position: absolute;
	inset: 0 0 auto;
	height: 1px;
	background: var(--top-highlight);
	pointer-events: none;
}

.header {
	position: sticky;
	top: 0;
	z-index: 20;
	width: 100%;
	border-bottom: 1px solid var(--container-border);
	background: color-mix(in srgb, var(--container-background) 90%, transparent);
	box-shadow: var(--surface-shadow);
	backdrop-filter: blur(20px);
	-webkit-backdrop-filter: blur(20px);
}

.header-container {
	width: min(1200px, calc(100% - 2rem));
	min-height: 74px;
	margin: 0 auto;
	padding: 0.75rem 0;
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 1rem;
}

.brand {
	flex: 1 1 55%;
	min-width: 0;
	display: flex;
	align-items: center;
	gap: 0.75rem;
	color: inherit;
	text-decoration: none;
}

.brand img {
	width: 36px;
	height: 36px;
	flex: 0 0 auto;
	border-radius: 10px;
	box-shadow: var(--icon-shadow);
}

h1,
h2,
p {
	margin: 0;
}

h1 {
	font-size: clamp(1.15rem, 2.4vw, 1.45rem);
	line-height: 1.2;
	letter-spacing: -0.025em;
	color: var(--heading-color);
}

.controls {
	display: flex;
	align-items: center;
	gap: 10px;
	flex: 0 0 auto;
}

.sr-only {
	position: absolute;
	width: 1px;
	height: 1px;
	padding: 0;
	margin: -1px;
	overflow: hidden;
	clip: rect(0, 0, 0, 0);
	white-space: nowrap;
	border: 0;
}

.language-menu__trigger,
#theme-toggle {
	min-height: 44px;
	border: 1px solid var(--control-border);
	border-radius: 12px;
	color: var(--text-primary);
	background: var(--control-background);
	box-shadow: var(--control-shadow);
	cursor: pointer;
	transition: border-color 160ms ease, background 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.language-menu {
	position: relative;
}

.language-menu__trigger {
	min-width: 146px;
	padding: 9px 12px;
	display: grid;
	grid-template-columns: auto 1fr auto;
	align-items: center;
	gap: 8px;
	font-weight: 700;
	text-align: left;
}

.language-menu__label {
	overflow: hidden;
	white-space: nowrap;
	text-overflow: ellipsis;
}

.language-menu__chevron {
	width: 1rem;
	height: 1rem;
	color: var(--text-secondary);
	transform: rotate(180deg);
	transform-origin: center;
	transition: transform 240ms cubic-bezier(0.34, 1.56, 0.64, 1), color 160ms ease;
}

.language-menu__trigger[aria-expanded="true"] .language-menu__chevron {
	color: var(--accent);
	transform: rotate(0deg);
}

.language-menu__panel {
	position: absolute;
	top: calc(100% + 8px);
	right: 0;
	z-index: 30;
	width: min(210px, calc(100vw - 1rem));
	padding: 7px;
	display: grid;
	gap: 3px;
	border: 1px solid var(--container-border);
	border-radius: 15px;
	background: var(--header-background);
	box-shadow: var(--container-shadow);
	backdrop-filter: blur(20px);
	-webkit-backdrop-filter: blur(20px);
	transform-origin: top right;
	animation: language-menu-in 160ms ease-out;
}

.language-menu__panel[hidden] {
	display: none;
}

.language-menu__option {
	min-height: 42px;
	padding: 9px 11px;
	display: grid;
	grid-template-columns: auto 1fr auto;
	align-items: center;
	gap: 8px;
	border: 1px solid transparent;
	border-radius: 11px;
	background: transparent;
	color: var(--text-primary);
	font: inherit;
	font-weight: 700;
	text-align: left;
	cursor: pointer;
	transition: border-color 160ms ease, background 160ms ease, color 160ms ease;
}

.language-menu__option:hover,
.language-menu__option:focus-visible {
	border-color: var(--control-border);
	background: var(--control-hover);
}

.language-menu__option[aria-checked="true"] {
	color: var(--accent);
}

.language-menu__check {
	opacity: 0;
	transform: scale(0.7);
	transition: opacity 160ms ease, transform 160ms ease;
}

.language-menu__option[aria-checked="true"] .language-menu__check {
	opacity: 1;
	transform: scale(1);
}

@keyframes language-menu-in {
	from {
		opacity: 0;
		transform: translateY(-6px) scale(0.98);
	}
}

#theme-toggle {
	width: 44px;
	padding: 0;
	display: inline-flex;
	align-items: center;
	justify-content: center;
	font-weight: 700;
}

.language-menu__trigger:hover,
#theme-toggle:hover {
	border-color: var(--accent);
	background: var(--control-hover);
	box-shadow: var(--control-hover-shadow);
	transform: translateY(-1px);
}

.theme-icon {
	line-height: 1;
}

.converter-section {
	padding: 22px;
	display: grid;
	gap: 14px;
	border: 1px solid var(--surface-border);
	border-radius: 20px;
	background: var(--surface-background);
	box-shadow: var(--surface-shadow), var(--surface-inset-shadow);
}

h2 {
	font-size: 1rem;
	line-height: 1.4;
	letter-spacing: 0.01em;
	color: var(--section-heading);
}

input[type="file"] {
	display: none;
}

.custom-file-label,
.btn {
	width: fit-content;
	max-width: 100%;
	min-height: 44px;
	margin: 0 auto;
	border: 1px solid var(--button-border);
	border-radius: 13px;
	padding: 11px 18px;
	display: inline-flex;
	align-items: center;
	justify-content: center;
	gap: 9px;
	font-weight: 750;
	line-height: 1.25;
	text-align: center;
	color: var(--button-text);
	background: var(--button-background);
	box-shadow: var(--button-shadow);
	cursor: pointer;
	transition: transform 160ms ease, box-shadow 160ms ease, filter 160ms ease;
}

.custom-file-label:hover,
.btn:hover {
	transform: translateY(-2px);
	filter: brightness(1.07);
	box-shadow: var(--button-hover-shadow);
}

.custom-file-label .icon {
	font-size: 1.15rem;
}

.selected-file-name {
	max-width: 220px;
	overflow: hidden;
	white-space: nowrap;
	text-overflow: ellipsis;
	font-size: 0.82rem;
	opacity: 0.82;
}

textarea {
	width: 100%;
	min-height: 118px;
	border: 1px solid var(--input-border);
	border-radius: 15px;
	padding: 14px 16px;
	resize: vertical;
	font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
	font-size: 0.9rem;
	line-height: 1.55;
	color: var(--text-primary);
	background: var(--input-background);
	box-shadow: var(--input-shadow);
	transition: border-color 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

textarea::placeholder {
	color: var(--placeholder-color);
}

textarea:focus {
	border-color: var(--accent);
	box-shadow: var(--input-focus-shadow);
	outline: none;
}

.preview {
	min-height: 42px;
	display: grid;
	place-items: center;
	color: var(--text-secondary);
}

.preview img {
	max-width: min(100%, 360px);
	max-height: 280px;
	border: 1px solid var(--surface-border);
	border-radius: 16px;
	background: var(--input-background);
	box-shadow: var(--preview-shadow);
	animation: fade-in 300ms ease-out;
}

.note {
	padding: 13px 16px;
	border: 1px solid var(--note-border);
	border-radius: 14px;
	font-size: 0.9rem;
	font-weight: 600;
	line-height: 1.5;
	text-align: center;
	color: var(--note-text);
	background: var(--note-background);
}

.error {
	font-weight: 700;
	color: var(--error-color);
}

:where(button, select, textarea, .custom-file-label):focus-visible {
	outline: 3px solid var(--focus-ring);
	outline-offset: 3px;
}

@keyframes fade-in {
	from {
		opacity: 0;
		transform: translateY(8px);
	}
}

@media (max-width: 680px) {
	.container {
		width: calc(100% - 1rem);
		margin: 1rem auto;
		padding: 14px;
		border-radius: 22px;
	}

	.header-container {
		width: calc(100% - 1.5rem);
		min-height: 66px;
	}

	.converter-section {
		padding: 17px;
	}
}

@media (max-width: 390px) {
	.header-container {
		gap: 0.5rem;
	}

	.brand {
		gap: 0.5rem;
	}

	.brand img {
		width: 32px;
		height: 32px;
	}

	h1 {
		font-size: 1.05rem;
	}

	.controls {
		gap: 0.4rem;
	}

	.language-menu__trigger {
		width: 54px;
		min-width: 54px;
		padding: 0.3rem;
		grid-template-columns: 1fr auto;
	}

	.language-menu__label { display: none; }

	#theme-toggle {
		width: 42px;
		min-height: 42px;
	}
}

@media (prefers-reduced-motion: reduce) {
	.language-menu__panel {
		animation: none;
	}
}