/* =========================
   DESIGN TOKENS
========================= */

:root {
	--bg: #e2e8f8;
	--surface: #ffffff;
	--text: #1f2937;
	--muted: #6b7280;
	--border: #e2e8f8;

	--primary: #1240f8;
	--primary-soft: #dbe4ff;
	--fading: #b1c0fc;
	--dim: #6b7280;

	/*for gradients*/
	--start: rgba(228, 191, 255, 0.4);
	--mid: rgba(196, 254, 255, 0.4);
	--end: rgba(255, 237, 209, 0.4);

	--radius: 50px;
	--max-width: 72ch;
}

/* Auto Dark */
@media (prefers-color-scheme: dark) {
	:root {
		--bg: #0b0e1d;
		--surface: #111827;
		--text: #e2e8f8;
		--muted: #9ca3af;
		--border: #1f2937;
		--primary: #2f6df6;
		--primary-soft: #182044;
		--fading: #1240f8;
		--dim: #1f2937;

		/*for gradients*/
		--start: rgba(16, 3, 23, 1);
		--mid: rgba(2, 7, 26, 1);
		--end: rgba(3, 42, 43, 1);
	}
}

/* Manual Override */
[data-theme="dark"] {
	--bg: #0b0e1d;
	--surface: #111827;
	--text: #e2e8f8;
	--muted: #9ca3af;
	--border: #1f2937;
	--primary: #2f6df6;
	--primary-soft: #182044;
	--fading: #1240f8;
	--dim: #1f2937;

	/*for gradients*/
	--start: rgba(16, 3, 23, 1);
	--mid: rgba(3, 12, 46, 1);
	--end: rgba(3, 42, 43, 1);
}

[data-theme="light"] {
	--bg: #e2e8f8;
	--surface: #ffffff;
	--text: #1f2937;
	--muted: #6b7280;
	--border: #e5e7eb;
	--primary: #1240f8;
	--primary-soft: #dbe4ff;
	--fading: #b1c0fc;
	--dim: var(--bg);

	/*for gradients*/
	--start: rgba(228, 191, 255, 0.4);
	--mid: rgba(196, 254, 255, 0.4);
	--end: rgba(255, 237, 209, 0.4);
}

/* =========================
   BASE
========================= */

*,
*::before,
*::after {
	box-sizing: border-box;
}

html {
	font-size: 18px;
	scroll-behavior: smooth;
}

body {
	margin: 0;
	font-family: "Inter", system-ui, sans-serif;
	background: var(--bg);
	color: var(--text);
	line-height: 1.8;
	-webkit-font-smoothing: antialiased;
	font-size: clamp(1rem, 1.05vw + 1rem, 1.125rem);
	background: linear-gradient(
		94deg,
		var(--start) 0%,
		var(--mid) 30%,
		var(--end) 90%
	);
}

/* =========================
   TYPOGRAPHY
========================= */

h1,
h2,
h3 {
	font-family: "Poppins", sans-serif;
	line-height: 1.15;
	margin: 3rem 0 1.25rem;
}

h1 {
	font-size: clamp(2rem, 3vw, 2.5rem);
	font-weight: 700;
}
h2 {
	font-size: clamp(1.6rem, 2.5vw, 2.2rem);
	font-weight: 600;
}
h3 {
	font-size: 1.25rem;
	font-weight: 500;
	color: var(--primary);
}

p {
	margin: 1.2rem 0;
}

strong {
	font-weight: 600;
}

a {
	color: var(--primary);
	text-decoration: none;
}

a:hover {
	text-decoration: underline;
}

/* =========================
   LONG FORM STORY LAYOUT
========================= */

.article {
	max-width: var(--max-width);
	margin: 0 auto;
	padding: 4rem 2rem;
    border-left: 1px solid var(--primary-soft); /* vertical line on left */
}

.article p {
	font-size: 1.05rem;
}

.article h2 {
	margin-top: 2rem;
}

.article blockquote {
	background: var(--primary-soft);
	padding: 1.2rem 1.5rem;
	border-left: 4px solid var(--primary);
	border-radius: var(--radius);
	margin: 2rem 0;
	color: var(--muted);
	font-style: italic;
}

.article hr {
	border: none;
	border-top: 1px solid var(--border);
	margin: 4rem 0;
}

.callout {
	background: var(--primary-soft);
	border-left: 4px solid var(--primary);
	padding: 1rem 1.5rem;
	margin: 2rem 0;
	font-weight: 500;
	font-size: clamp(12px, 1rem + 0.5vw, 16px);
	color: var(--muted);
}

.article h1 {
	background: linear-gradient(90deg, var(--fading), transparent 70%);
	border-radius: var(--radius);
	display: inline-block;
	padding: 1rem;
	padding-left: 3rem;
	text-align: center;
	display: block;
}
.article h2 {
	background: linear-gradient(90deg, var(--fading), transparent 70%);
	border-radius: var(--radius);
	display: inline-block;
	padding: 1rem;
	padding-left: 2rem;
}

/* =========================
   SUBTLE NOTEBOOK BACKGROUND
========================= */
main {
	position: relative;
	background-image: 

    /* Layer 2: repeating notebook lines */ repeating-linear-gradient(
		to bottom,
		var(--primary-soft) 0px,
		var(--dim) 1px,
		transparent 1px,
		transparent 1.9rem
	);

	background-repeat: repeat;
	background-size: auto;
}
/* =========================
   SECTIONS
========================= */

.section {
	padding: 5rem 1.5rem;
}

.surface {
	background: var(--surface);
	border-radius: var(--radius);
	padding: 2.5rem;
	border: 1px solid var(--border);
}

/* Gamma-style soft gradient */
.gradient {
	background: linear-gradient(135deg, var(--primary-soft), transparent 70%);
}

/* =========================
   BUTTONS
========================= */

.button {
	display: inline-block;
	padding: 0.85rem 1.5rem;
	border-radius: 999px;
	background: var(--primary);
	color: white;
	font-weight: 600;
	transition: 0.2s ease;
}

.button:hover {
	opacity: 0.9;
	transform: translateY(-2px);
}

/* =========================
   NAV
========================= */

nav {
	display: flex;
	justify-content: space-between;
	align-items: center;
	padding: 1.5rem;
	background: var(--surface);
	box-shadow: 0 10px 10px var(--primary-soft);
}

nav a {
	margin-left: 1.5rem;
	font-weight: 500;
}

nav a:hover {
	color: var(--primary);
	text-decoration: underline;
}

/* =========================
   THEME TOGGLE
========================= */

.theme-toggle {
	background: none;
	border: 1px solid var(--border);
	border-radius: 999px;
	padding: 0.4rem 0.9rem;
	cursor: pointer;
	color: var(--text);
}