:root {
	--bg: #f4f7fb;
	--surface: #ffffff;
	--surface-soft: #f8fafc;
	--text: #162032;
	--muted: #5d6779;
	--line: #d8e0ea;

	--brand-900: #111827;
	--brand-800: #115e59;
	--brand-700: #0f766e;

	--accent: #d97706;

	--shadow: 0 18px 48px rgba(15, 23, 42, 0.08);

	--radius-lg: 24px;
	--radius-md: 16px;
	--radius-sm: 12px;

	--container: 1100px;
}

* {
	box-sizing: border-box;
}

html {
	scroll-behavior: smooth;
}

body {
	margin: 0;
	min-height: 100vh;

	font-family: 'Source Sans 3', sans-serif;

	color: var(--text);

	background:
		radial-gradient(circle at top left, rgba(15, 118, 110, 0.12), transparent 24%),
		radial-gradient(circle at top right, rgba(217, 119, 6, 0.1), transparent 20%), var(--bg);
}

a {
	color: inherit;
	text-decoration: none;
}

img {
	max-width: 100%;
}

.container {
	width: min(calc(100% - 2rem), var(--container));
	margin: 0 auto;
}

/* HEADER */

.site-header {
	background: linear-gradient(135deg, #111827, #1f2937);
	color: #fff;
}

.header-inner {
	display: flex;
	justify-content: space-between;
	align-items: center;
	gap: 1rem;
	padding: 1rem 0;
}

.site-brand {
	font-family: 'Space Grotesk', sans-serif;
	font-size: 1.6rem;
	font-weight: 700;
	letter-spacing: -0.04em;
}

.site-tagline {
	margin: 0;
	color: rgba(255, 255, 255, 0.72);
}

/* MAIN */

.site-main {
	padding: 2rem 0 4rem;
}

.site-footer {
	padding: 0 0 2rem;
}

.footer-inner {
	text-align: center;
	color: var(--muted);
}

/* SEARCH */

.search-box {
	position: relative;
	margin-top: 20px;
	max-width: 520px;
}

.search-box input {
	width: 100%;
	padding: 12px 16px 12px 40px;

	font-family: 'Source Sans 3', sans-serif;
	font-size: 16px;

	border-radius: 10px;
	border: 1px solid #d1d5db;

	background: #fff;

	outline: none;

	transition:
		border-color 0.2s ease,
		box-shadow 0.2s ease;
}

.search-box input:hover {
	border-color: #9ca3af;
}

.search-box input:focus {
	border-color: #2563eb;
	box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.search-box::before {
	content: '🔍';

	position: absolute;
	left: 12px;
	top: 50%;

	transform: translateY(-50%);

	opacity: 0.6;
	font-size: 14px;
}

/* CARDS */

.hero,
.content-card,
.seo-card,
.category-block,
.link-block,
.ad-slot {
	background: var(--surface);
	border: 1px solid var(--line);
	border-radius: var(--radius-lg);
	box-shadow: var(--shadow);
}

.hero,
.content-card,
.seo-card,
.category-block,
.link-block {
	padding: 1.5rem;
}

.hero {
	margin-bottom: 1.5rem;
}

.hero h1,
.page-title {
	margin: 0 0 0.75rem;

	font-family: 'Space Grotesk', sans-serif;
	font-size: clamp(2rem, 4vw, 3.2rem);

	line-height: 1;

	letter-spacing: -0.05em;
}

.hero p,
.lead,
.muted,
.seo-card p,
.seo-card li,
.tool-card p,
.category-note,
.example-list li {
	color: var(--muted);
	line-height: 1.65;
}

/* GRID */

.homepage-grid,
.converter-layout {
	display: grid;
	gap: 1.5rem;
}

.section-title {
	margin: 0 0 1rem;
	font-family: 'Space Grotesk', sans-serif;
	font-size: 1.35rem;
	letter-spacing: -0.03em;
}

.tool-grid,
.related-grid {
	display: grid;

	grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));

	gap: 1rem;
}

/* TOOL CARDS */

.tool-card,
.related-card {
	display: block;

	padding: 1rem;

	border: 1px solid var(--line);
	border-radius: var(--radius-md);

	background: var(--surface-soft);

	transition:
		transform 0.18s ease,
		border-color 0.18s ease,
		box-shadow 0.18s ease;
}

.tool-card:hover,
.related-card:hover {
	transform: translateY(-4px) scale(1.01);

	border-color: rgba(15, 118, 110, 0.4);

	box-shadow: 0 12px 28px rgba(0, 0, 0, 0.09);
}

.tool-card h3,
.related-card h3 {
	margin: 0 0 0.35rem;

	font-size: 1.08rem;
}

/* AD SLOT */

.ad-slot {
	display: grid;
	place-items: center;

	min-height: 110px;

	padding: 1rem;

	text-align: center;

	color: var(--muted);

	border-style: dashed;
}

/* BREADCRUMB */

.breadcrumb {
	display: flex;
	flex-wrap: wrap;

	gap: 0.35rem;

	margin-bottom: 1rem;

	color: var(--muted);
	font-weight: 600;
}

.breadcrumb a {
	color: var(--brand-800);
}

/* BUTTONS */

button,
.btn,
.convert-button {
	cursor: pointer;

	transition:
		transform 0.12s ease,
		box-shadow 0.12s ease,
		background-color 0.15s ease;
}

button:hover,
.btn:hover,
.convert-button:hover {
	transform: translateY(-2px);
	box-shadow: 0 6px 14px rgba(0, 0, 0, 0.12);
}

button:active,
.btn:active,
.convert-button:active {
	transform: translateY(0);
	box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

.clear-button {
	transition:
		background 0.15s ease,
		transform 0.12s ease;
}

.clear-button:hover {
	background: #e5e7eb;
	transform: translateY(-1px);
}

/* RESULT ANIMATION */

#converter-result {
	transition:
		transform 0.2s ease,
		opacity 0.2s ease;
}

.result-update {
	animation: resultFlash 0.25s ease;
}

@keyframes resultFlash {
	0% {
		transform: scale(0.98);
		opacity: 0.6;
	}

	100% {
		transform: scale(1);
		opacity: 1;
	}
}

/* CONVERTER */

.converter-layout {
	grid-template-columns:
		minmax(0, 1.6fr)
		minmax(280px, 1fr);

	align-items: start;
}

.converter-form {
	display: grid;
	gap: 1rem;

	margin-top: 1.25rem;
}

.field {
	display: grid;
	gap: 0.45rem;
}

.field label {
	font-weight: 700;
}

.field input {
	width: 100%;

	padding: 0.95rem 1rem;

	border: 1px solid var(--line);
	border-radius: var(--radius-sm);

	font: inherit;
	font-size: 1.05rem;

	color: var(--text);
	background: #fff;

	transition:
		border-color 0.2s ease,
		box-shadow 0.2s ease;
}

.field input:focus {
	outline: 3px solid rgba(15, 118, 110, 0.14);
	border-color: rgba(15, 118, 110, 0.7);
}

.action-row {
	display: flex;
	flex-wrap: wrap;
	gap: 0.75rem;
}

.button {
	appearance: none;

	border: 0;

	border-radius: 999px;

	background: linear-gradient(135deg, var(--brand-700), var(--brand-800));

	color: #fff;

	padding: 0.85rem 1.2rem;

	font: inherit;
	font-weight: 700;

	cursor: pointer;
}

.button.secondary {
	background: #e8edf3;
	color: var(--text);
}

/* RESULT BOX */

.result-box,
.formula-box,
.examples-box {
	margin-top: 1rem;

	padding: 1rem 1.1rem;

	border: 1px solid var(--line);
	border-radius: var(--radius-md);

	background: var(--surface-soft);
}

.result-label,
.mini-label {
	display: block;

	margin-bottom: 0.4rem;

	color: var(--muted);

	font-size: 0.92rem;
	font-weight: 700;

	text-transform: uppercase;
	letter-spacing: 0.04em;
}

.result-value {
	font-family: 'Space Grotesk', sans-serif;

	font-size: clamp(1.8rem, 4vw, 2.7rem);

	font-weight: 700;

	letter-spacing: -0.05em;
}

.example-list {
	margin: 0;
	padding-left: 1.15rem;
}

/* RESPONSIVE */

@media (max-width: 860px) {
	.converter-layout {
		grid-template-columns: 1fr;
	}
}

@media (max-width: 720px) {
	.header-inner {
		flex-direction: column;
		align-items: flex-start;
	}

	.hero,
	.content-card,
	.seo-card,
	.category-block,
	.link-block {
		padding: 1.2rem;
	}
}