:root {
	--panel: rgba(18, 26, 37, 0.96);
	--panel-soft: rgba(28, 39, 54, 0.94);
	--stroke: rgba(255, 255, 255, 0.08);
	--text: #f8fafc;
	--muted: #b7c4d2;
	--accent: #ff9e57;
	--accent-2: #ffc44d;
	--cyan: #78e5d4;
	--shadow: 0 18px 48px rgba(0, 0, 0, 0.28);
	--radius: 18px;
	--radius-sm: 12px;
	--mono: "Cascadia Code", "Iosevka", "SFMono-Regular", monospace;
	--sans: "Segoe UI Variable Display", "Bahnschrift", "Aptos", sans-serif;
}

* {
	box-sizing: border-box;
}

[hidden] {
	display: none !important;
}

html,
body {
	margin: 0;
	height: 100%;
}

body {
	font-family: var(--sans);
	color: var(--text);
	background:
		radial-gradient(circle at top left, rgba(255, 158, 87, 0.22), transparent 28%),
		radial-gradient(circle at top right, rgba(120, 229, 212, 0.16), transparent 26%),
		linear-gradient(180deg, #0b1016 0%, #101821 100%);
	overflow-x: hidden;
	overflow-y: auto;
	padding: 6px;
}

button,
input,
select,
textarea {
	font: inherit;
}

button {
	border: none;
}

.app-shell {
	width: min(1400px, 100%);
	height: calc(100svh - 12px);
	margin: 0 auto;
	padding: 8px;
	display: grid;
	grid-template-rows: auto minmax(0, 1fr) auto;
	gap: 8px;
	background: var(--panel);
	border: 1px solid var(--stroke);
	border-radius: 22px;
	box-shadow: var(--shadow);
	backdrop-filter: blur(18px);
	overflow: hidden;
}

.topbar,
.display-card,
.keypad-panel,
.lane {
	background: var(--panel-soft);
	border: 1px solid var(--stroke);
	border-radius: var(--radius);
}

.topbar {
	padding: 8px 10px;
	display: grid;
	grid-template-columns: auto minmax(0, 1fr) auto;
	align-items: center;
	gap: 8px;
}

.brand-mark {
	font-size: 0.84rem;
	letter-spacing: 0.16em;
	text-transform: uppercase;
	color: #ffe4a1;
}

.control-row {
	display: grid;
	grid-template-columns: 58px 58px minmax(0, 1fr);
	gap: 6px;
	align-items: end;
}

.compact-field {
	display: grid;
	gap: 4px;
}

.compact-field span,
.lane-title {
	font-size: 0.68rem;
	color: var(--muted);
}

.compact-field input,
.compact-field select,
.expression-input {
	width: 100%;
	border: 1px solid rgba(255, 255, 255, 0.12);
	border-radius: 10px;
	padding: 7px 9px;
	background: rgba(7, 12, 18, 0.82);
	color: var(--text);
	outline: none;
}

.workspace {
	min-height: 0;
	display: grid;
	grid-template-columns: minmax(280px, 0.92fr) minmax(420px, 1.08fr);
	gap: 8px;
	overflow: hidden;
}

.display-card {
	padding: 8px;
	display: grid;
	grid-template-rows: auto auto minmax(52px, auto) minmax(0, 1fr);
	gap: 6px;
	min-height: 0;
}

.display-head {
	display: flex;
	justify-content: flex-end;
}

.display-actions {
	display: flex;
	gap: 6px;
	flex-wrap: wrap;
}

.action-button {
	min-width: 34px;
	padding: 0 10px;
	border-radius: 999px;
	background: rgba(255, 255, 255, 0.08);
	color: var(--text);
	cursor: pointer;
}

.history-toggle {
	justify-self: end;
	height: 32px;
	padding: 0 12px;
	border-radius: 999px;
	background: rgba(255, 255, 255, 0.08);
	color: var(--text);
	cursor: pointer;
}

.history-toggle[aria-expanded="true"] {
	background: linear-gradient(135deg, rgba(255, 158, 87, 0.28), rgba(255, 196, 77, 0.2));
}

.action-button.accent {
	background: linear-gradient(135deg, rgba(255, 158, 87, 0.28), rgba(255, 196, 77, 0.2));
}

.editor-box {
	position: relative;
	min-height: 0;
	overflow: hidden;
}

.expression-input {
	min-height: 68px;
	height: 100%;
	resize: none;
	font-family: var(--mono);
	font-size: 0.92rem;
	line-height: 1.45;
	overflow: auto;
	padding: 10px 12px;
	border: 1px solid rgba(255, 255, 255, 0.12);
	white-space: pre-wrap;
	overflow-wrap: anywhere;
	word-break: break-word;
	tab-size: 4;
}

.expression-ghost {
	position: absolute;
	inset: 1px;
	padding: 10px 12px;
	color: rgba(183, 196, 210, 0.55);
	font-family: var(--mono);
	font-size: 0.92rem;
	line-height: 1.45;
	pointer-events: none;
	white-space: pre-wrap;
	overflow-wrap: anywhere;
	word-break: break-word;
	tab-size: 4;
	overflow: auto;
	border: 1px solid transparent;
	scrollbar-width: none;
}

.expression-ghost::-webkit-scrollbar {
	display: none;
}

.ghost-prefix {
	visibility: hidden;
}

.ghost-suffix {
	color: rgba(183, 196, 210, 0.55);
}

.virtual-cursor {
	display: inline-block;
	width: 2px;
	height: 1.15em;
	background-color: var(--accent);
	margin-left: -1px;
	margin-right: -1px;
	vertical-align: text-bottom;
	animation: ghost-blink 1s step-end infinite;
}

@keyframes ghost-blink {
	50% {
		opacity: 0;
	}
}

.math-preview,
.result-card {
	border-radius: var(--radius-sm);
	border: 1px solid rgba(255, 255, 255, 0.08);
	background: rgba(255, 255, 255, 0.04);
	min-width: 0;
}

.math-preview {
	padding: 8px 10px;
	min-height: 52px;
	display: flex;
	align-items: center;
	overflow: auto;
	font-size: 0.9rem;
}

.result-card {
	padding: 8px 10px;
	display: grid;
	grid-template-rows: minmax(0, 1fr) auto;
	gap: 4px;
	min-height: 0;
}

.result-output-wrap {
	max-height: 100%;
	min-height: 2.3em;
	overflow: auto;
	scrollbar-width: thin;
}

.result-output {
	display: block;
	font-family: var(--mono);
	font-size: clamp(0.82rem, 0.55vw + 0.66rem, 0.98rem);
	font-weight: 700;
	line-height: 1.28;
	white-space: pre-wrap;
	overflow-wrap: anywhere;
	word-break: break-word;
}

.keypad-panel {
	position: relative;
	padding: 8px;
	display: grid;
	grid-template-rows: auto minmax(0, 1fr);
	gap: 6px;
	min-height: 0;
	overflow: visible;
}

.keypad-toolbar {
	display: flex;
	flex-wrap: wrap;
	gap: 6px;
}

.mini-toggle,
.function-chip {
	min-height: 30px;
	padding: 0 10px;
	border-radius: 999px;
	background: rgba(255, 255, 255, 0.08);
	color: var(--text);
	cursor: pointer;
	border: 1px solid rgba(255, 255, 255, 0.08);
	display: inline-flex;
	align-items: center;
	justify-content: center;
	font-size: 0.8rem;
}

.key.ex {
	position: relative;
	gap: 0;
	font-size: 0.85rem;
	padding: 0 4px;
}

.ex-icon {
	position: absolute;
	right: 3px;
	bottom: 3px;
	display: inline-block;
	width: 0.3em;
	height: 0.3em;
	border-right: 0.1em solid currentColor;
	border-bottom: 0.1em solid currentColor;
	transform: rotate(45deg);
	opacity: 0.5;
	transition: transform 0.2s ease;
}

.key.ex[data-active="true"] {
	background: linear-gradient(135deg, rgba(255, 158, 87, 0.42), rgba(255, 196, 77, 0.34));
	border-color: rgba(255, 196, 77, 0.6);
	color: #fff;
	box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.2);
}

.key.ex[data-active="true"] .ex-icon {
	transform: rotate(225deg);
	opacity: 1;
}

.keypad-grid {
	align-self: stretch;
	min-height: 0;
	display: grid;
	grid-template-columns: repeat(6, minmax(0, 1fr));
	grid-template-rows: repeat(6, 1fr);
	gap: 6px;
}

.key {
	min-height: clamp(34px, 4.8svh, 48px);
	min-width: 0;
	border-radius: 12px;
	background: rgba(255, 255, 255, 0.06);
	color: var(--text);
	font-weight: 700;
	font-size: 0.5rem;
	cursor: pointer;
	display: flex;
	align-items: center;
	justify-content: center;
	padding: 0 4px;
	overflow: hidden;
}

.key .katex {
	display: block;
}

.key .katex-display {
	margin: 0;
}

.key .katex-display {
	margin: 0;
}

.key.function {
	background: rgba(255, 255, 255, 0.1);
	color: #ffe6a9;
}

.key.pager-button {
	background: linear-gradient(180deg, rgba(120, 229, 212, 0.22), rgba(120, 229, 212, 0.14));
	color: #78e5d4;
	border: 1px solid rgba(120, 229, 212, 0.3);
}

.key.pager-button:active {
	background: linear-gradient(180deg, rgba(120, 229, 212, 0.32), rgba(120, 229, 212, 0.24));
}

.key.accent {
	background: linear-gradient(180deg, rgba(255, 158, 87, 0.22), rgba(255, 158, 87, 0.14));
}

.key.equals {
	background: linear-gradient(135deg, var(--accent), var(--accent-2));
	color: #151a20;
}

.key.span2 {
	grid-column: span 2;
}

.lane {
	padding: 8px 10px;
}

.lane-title {
	font-weight: 700;
	letter-spacing: 0.04em;
	text-transform: uppercase;
}

.history-lane {
	overflow: hidden;
}

.history-list {
	list-style: none;
	margin: 6px 0 0;
	padding: 0;
	display: grid;
	grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
	gap: 6px;
}

.history-card {
	background: rgba(255, 255, 255, 0.04);
	border: 1px solid rgba(255, 255, 255, 0.08);
	border-radius: 12px;
	min-width: 0;
}

.history-button {
	width: 100%;
	max-height: 30em;
	padding: 8px;
	background: transparent;
	color: var(--text);
	text-align: left;
	cursor: pointer;
}

.history-expression,
.history-result {
	display: block;
	font-family: var(--mono);
	font-size: 0.78rem;
	overflow-wrap: anywhere;
}

.history-result {
	margin-top: 4px;
}

.katex {
	font-size: 0.94em;
}

.fit-wrapper {
	min-width: 0;
	width: 100%;
	height: 100%;
	align-content: center;
	overflow: hidden;
	transform: scale(0.8);
	transform-origin: center;
}

.fit {
	display: inline-block;
	white-space: nowrap;
}

@media (max-width: 980px) {
	.app-shell {
		height: auto;
		min-height: calc(100svh - 12px);
	}

	.topbar {
		grid-template-columns: auto 1fr;
	}

	.history-toggle {
		grid-column: 1 / -1;
		justify-self: stretch;
	}

	.workspace {
		grid-template-columns: 1fr;
		grid-template-rows: minmax(0, 0.92fr) minmax(0, 1.08fr);
	}
}

@media (max-width: 640px) {
	body {
		padding: 4px;
	}

	.app-shell {
		height: auto;
		min-height: calc(100svh - 8px);
		padding: 6px;
		gap: 6px;
		border-radius: 16px;
		overflow: visible;
	}

	.topbar {
		padding: 6px;
		gap: 6px;
		grid-template-columns: 1fr;
	}

	.control-row {
		grid-template-columns: 52px 52px minmax(0, 1fr);
	}

	.display-card,
	.keypad-panel {
		padding: 6px;
	}

	.workspace {
		overflow: visible;
	}

	.display-card {
		grid-template-rows: auto auto minmax(44px, auto) auto;
		overflow: visible;
	}

	.expression-input {
		min-height: 58px;
		font-size: 0.86rem;
	}

	.expression-ghost {
		font-size: 0.86rem;
	}

	.math-preview {
		min-height: 44px;
		max-height: 10em;
		padding: 6px 8px;
	}

	.result-card {
		padding: 6px 8px;
	}

	.result-output-wrap {
		max-height: 10em;
	}

	.result-output {
		font-size: clamp(0.74rem, 0.3vw + 0.7rem, 0.9rem);
	}

	.mini-toggle {
		flex: 1 1 calc(25% - 6px);
	}

	.keypad-grid {
		gap: 5px;
	}

	.key {
		min-height: clamp(32px, 4.2svh, 42px);
		padding: 0 1px;
	}
}

@media (max-width: 320px) {
	.keypad-grid {
		gap: 3px;
	}

	.key {
		border-radius: 8px;
	}

	.key.ex {
		padding: 0;
	}

	.ex-icon {
		margin-left: 0.1em;
		width: 0.35em;
		height: 0.35em;
	}
}