/* 1) Reset and base */
*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    color-scheme: light dark;
}

html,
body {
    min-height: 100%;
}

body {
    margin: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
    line-height: 1.5;
    color: var(--fg);
}

img,
svg,
video,
canvas {
    display: block;
    max-width: 100%;
}

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

/* 2) Design tokens */
:root {
    --bg: #ffffff;
    --fg: #0f172a;
    /* slate-900 */
    --muted: #425173;
    /* darker muted tone for better readability */
    --border: #e2e8f0;
    /* slate-200 */
    --card: #ffffff;
    --accent: #2563eb;
    /* blue-600 */
    --accent-contrast: #ffffff;
    --radius: 12px;
    --shadow: 0 1px 2px rgba(0, 0, 0, .06), 0 8px 24px rgba(0, 0, 0, .08);
    /* Fluid type scale */
    --step-0: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
    --step-1: clamp(1.25rem, 1.1rem + 0.8vw, 1.5rem);
    --step-2: clamp(1.5rem, 1.35rem + 1.2vw, 2rem);
    --step-3: clamp(1.875rem, 1.6rem + 1.8vw, 2.5rem);
    --container-max: 72rem;
    /* 1152px */
}


/* 3) Layout helpers */
.container {
    width: min(100% - 2rem, var(--container-max));
    margin-inline: auto;
}

.stack>*+* {
    margin-top: 1rem;
}

/* 4) Typography */
h1,
h2,
h3 {
    line-height: 1.2;
    margin: 0 0 0.5rem;
}

h1 {
    font-size: var(--step-3);
}

h2 {
    font-size: var(--step-2);
}

h3 {
    font-size: var(--step-1);
}

p {
    margin: 0 0 1rem;
    color: var(--muted);
}

a {
    color: var(--accent);
    text-underline-offset: 2px;
}

a:hover {
    text-decoration: underline;
}

/* 5) Components */
.skip-link {
    position: absolute;
    left: -9999px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
}

.skip-link:focus {
    left: 1rem;
    top: 1rem;
    width: auto;
    height: auto;
    padding: 0.5rem 0.75rem;
    background: var(--accent);
    color: var(--accent-contrast);
    border-radius: 0.5rem;
    z-index: 1000;
}

header.site-header {
    position: sticky;
    top: 0;
    z-index: 10;
    background: color-mix(in srgb, var(--bg) 92%, transparent);
    backdrop-filter: saturate(180%) blur(8px);
    border-bottom: 1px solid var(--border);
}

.site-header .bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    padding: 0.75rem 0;
}

.brand {
    font-weight: 700;
    letter-spacing: 0.2px;
}

.nav-toggle {
    border: 1px solid var(--border);
    background: var(--card);
    color: var(--fg);
    padding: 0.5rem 0.75rem;
    border-radius: 0.5rem;
    display: inline-flex;
    gap: 0.5rem;
    align-items: center;
}

.nav-toggle:hover {
    box-shadow: var(--shadow);
}

nav.primary-nav {
    border-top: 1px solid var(--border);
}

nav.primary-nav[hidden] {
    display: none;
}

nav.primary-nav ul {
    list-style: none;
    margin: 0;
    padding: 0.25rem 0;
    display: grid;
    gap: 0.25rem;
}

nav.primary-nav a {
    display: block;
    padding: 0.5rem;
    border-radius: 0.5rem;
    color: inherit;
    text-decoration: none;
}

nav.primary-nav a:hover {
    background: color-mix(in srgb, var(--accent) 12%, transparent);
}

@media (min-width: 48rem) {
    .nav-toggle {
        display: none;
    }

    nav.primary-nav {
        border-top: 0;
    }

    nav.primary-nav[hidden] {
        display: block;
    }

    nav.primary-nav ul {
        display: flex;
        gap: 0.5rem;
    }
}


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

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 0.9rem;
    border-radius: 0.625rem;
    border: 1px solid var(--border);
    background: var(--card);
    color: var(--fg);
    text-decoration: none;
}

.btn:hover {
    box-shadow: var(--shadow);
}

.btn.primary {
    background: var(--accent);
    color: var(--accent-contrast);
    border-color: transparent;
}