body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

main {
    flex: 1;
}

.skip-link {
    position: absolute;
    left: -9999px;
    top: 0;
    z-index: 100;
    padding: var(--space-2) var(--space-4);
    background-color: var(--color-accent);
    color: #ffffff;
    text-decoration: none;
    border-radius: var(--radius-sm);
}

.skip-link:focus {
    left: var(--space-4);
    top: var(--space-4);
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background-color: rgba(255, 255, 255, 0.92);
    backdrop-filter: saturate(180%) blur(8px);
    -webkit-backdrop-filter: saturate(180%) blur(8px);
    border-bottom: 1px solid var(--color-border);
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-block: var(--space-4);
}

.site-header__logo {
    font-family: var(--font-mono);
    font-size: var(--fs-lg);
    font-weight: 700;
    color: var(--color-fg);
    text-decoration: none;
    letter-spacing: -0.05em;
}

.site-header__logo:hover {
    color: var(--color-accent);
}

.site-nav {
    display: none;
}

.site-nav__list {
    display: flex;
    gap: var(--space-6);
    list-style: none;
    margin: 0;
    padding: 0;
}

.site-nav__link {
    color: var(--color-fg-muted);
    font-size: var(--fs-sm);
    font-weight: 500;
    text-decoration: none;
    transition: color var(--transition);
}

.site-nav__link:hover {
    color: var(--color-fg);
}

.site-nav__link--active {
    color: var(--color-fg);
    position: relative;
}

.site-nav__link--active::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: -8px;
    height: 2px;
    background-color: var(--color-accent);
    border-radius: var(--radius-sm);
}

.burger {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    width: 40px;
    height: 40px;
    padding: 4px;
    background: none;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
}

.burger:hover {
    border-color: var(--color-fg-muted);
}

.burger__bar {
    width: 20px;
    height: 2px;
    background-color: var(--color-fg);
    border-radius: 2px;
    transition: transform var(--transition), opacity var(--transition);
}

.burger[aria-expanded="true"] .burger__bar:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}

.burger[aria-expanded="true"] .burger__bar:nth-child(2) {
    opacity: 0;
}

.burger[aria-expanded="true"] .burger__bar:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

@media (min-width: 768px) {
    .site-nav {
        display: block;
    }
    .burger {
        display: none;
    }
}

.mobile-nav {
    position: fixed;
    inset: 0;
    z-index: 40;
    padding-top: 80px;
    padding-inline: var(--space-6);
    background-color: var(--color-bg);
    transform: translateY(-100%);
    transition: transform var(--transition);
    visibility: hidden;
}

.mobile-nav[aria-hidden="false"] {
    transform: translateY(0);
    visibility: visible;
}

.mobile-nav__list {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    list-style: none;
    margin: 0;
    padding: 0;
}

.mobile-nav__link {
    display: block;
    padding: var(--space-3) 0;
    font-size: var(--fs-xl);
    font-weight: 500;
    color: var(--color-fg);
    text-decoration: none;
    border-bottom: 1px solid var(--color-border);
}

.mobile-nav__link:hover {
    color: var(--color-accent);
}

@media (min-width: 768px) {
    .mobile-nav {
        display: none !important;
    }
}

.page-content {
    padding-block: var(--space-12);
}

@media (min-width: 768px) {
    .page-content {
        padding-block: var(--space-16);
    }
}

.site-footer {
    margin-top: var(--space-16);
    padding-block: var(--space-12);
    background-color: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
}

.site-footer__inner {
    display: grid;
    gap: var(--space-6);
}

@media (min-width: 768px) {
    .site-footer__inner {
        grid-template-columns: 1fr auto;
        align-items: center;
    }
}

.site-footer__copy {
    margin: 0;
    font-size: var(--fs-sm);
    color: var(--color-fg-muted);
}

.site-footer__links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-5);
    list-style: none;
    margin: 0;
    padding: 0;
}

.site-footer__link {
    color: var(--color-fg-muted);
    font-size: var(--fs-sm);
    text-decoration: none;
    transition: color var(--transition);
}

.site-footer__link:hover {
    color: var(--color-fg);
}