:root {
    --color-bg: #aafafa;
    --color-text: #1a1a1a;
    --color-accent: #2563eb;
    --color-border: #e5e7eb;
    --color-muted: #4b5563;

    --font-serif: Georgia, "Times New Roman", Times, serif;
    --font-fancy: fantasy;

    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 4rem;

    --max-width: 50rem;
    --border-radius: 0.5rem;

    --transition-fast: 0.2s ease;
    --transition-slow: 1s ease;
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #0a0a0a;
        --color-text: #f5f5f5;
        --color-accent: #60a5fa;
        --color-muted: #9ca3af;
        --color-border: #262626;
    }
}

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-serif);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;

    display: flex;
    flex-direction: column;

    /* Smooth color transitions for dark mode */
    transition:
        background-color var(--transition-slow),
        color var(--transition-slow);
}

/* Better default focus styles for accessibility */
:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 4px;
}

.container {
    width: 100%;
    max-width: var(--max-width);
    margin-inline: auto;
    padding-inline: var(--space-sm);
}

header {
    padding-block: var(--space-lg);
    border-bottom: 1px solid var(--color-accent);
}

main {
    padding-block: var(--space-xl);
    flex: 1; /* Grows to push footer to bottom */
}

footer {
    padding-block: var(--space-lg);
    border-top: 1px solid var(--color-accent);
    margin-top: auto; /* With flex, pushes footer to bottom */

    p {
        color: var(--color-muted);
        font-size: 0.875rem;
        text-align: center;
    }
}

.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-bg);
    color: white;
    padding: var(--space-xs) var(--space-sm);
    text-decoration: none;
    z-index: 100;
    border-radius: 0 0 4px 0;

    &:focus {
        top: 0;
    }
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-sm);
    flex-wrap: wrap;
}

.logo {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;

    &:hover {
        color: var(--color-accent);
    }
}

nav {
    ul {
        list-style: none;
        display: flex;
        gap: var(--space-md);
        flex-wrap: wrap;
    }

    a {
        color: var(--color-muted);
        text-decoration: none;
        transition: color var(--transition-fast);
        padding: var(--space-xs);

        &:hover,
        &:focus {
            color: var(--color-accent);
        }

        &:focus-visible {
            outline: 2px solid var(--color-accent);
            outline-offset: 4px;
            border-radius: 2px;
        }
    }
}

section {
    margin-bottom: var(--space-xl);
}

h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    color: var(--color-text);
}

.hero {
    margin-bottom: var(--space-xl);

    h1 {
        /* Fluid typography - scales between min and max */
        font-size: clamp(2rem, 5vw, 3rem);
        font-weight: 700;
        line-height: 1.2;
        margin-bottom: var(--space-sm);
    }

    p {
        font-size: clamp(1.125rem, 2vw, 1.25rem);
        color: var(--color-muted);
        max-width: 42rem;
    }
}

.fancy-text {
    font-family: var(--font-fancy);
}

.stack {
    display: inline-flex;
    flex-direction: column;
    vertical-align: middle;
    text-align: center;
    font-size: 0.55em;
    line-height: 0.9;
}

/* Responsive Grid - Auto-fits columns based on available space */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(18rem, 1fr));
    gap: var(--space-md);
}

.card {
    padding: var(--space-md);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    transition:
        border-color var(--transition-fast),
        transform var(--transition-fast);

    /* Hover effect - subtle lift */
    &:hover {
        border-color: var(--color-accent);
        transform: translateY(-2px);
    }

    h3 {
        font-size: 1.125rem;
        font-weight: 600;
        margin-bottom: var(--space-xs);
        color: var(--color-text);
    }

    p {
        color: var(--color-muted);
        font-size: 0.9375rem;
        margin-bottom: var(--space-sm);
        line-height: 1.5;
    }

    a {
        color: var(--color-accent);
        text-decoration: none;
        font-weight: 500;
        display: inline-block;

        &:hover {
            text-decoration: underline;
        }

        &:focus-visible {
            outline: 2px solid var(--color-accent);
            outline-offset: 2px;
            border-radius: 2px;
        }
    }
}

.social-links {
    margin-top: var(--space-md);

    ul {
        list-style: none;
        display: flex;
        gap: var(--space-md);
        flex-wrap: wrap;
    }

    a {
        color: var(--color-muted);
        text-decoration: none;
        transition: color var(--transition-fast);

        &:hover {
            color: var(--color-accent);
        }
    }
}

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

/* Small screens - Stack navigation if needed */
@media (max-width: 640px) {
    .header-content {
        flex-direction: column;
        align-items: flex-start;
    }

    nav ul {
        width: 100%;
        justify-content: flex-start;
    }
}

/* Medium screens and up - Optimize spacing */
@media (min-width: 768px) {
    .hero h1 {
        margin-bottom: var(--space-md);
    }

    section {
        margin-bottom: calc(var(--space-xl) * 1.5);
    }
}

/* ACCESSIBILITY: Respect user preferences for motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    html {
        scroll-behavior: auto;
    }
}