.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.5rem;
    padding: 0.875rem 1.25rem;
    margin: 0.75rem;
    background-color: rgba(255, 253, 247, 0.7);
    backdrop-filter: saturate(160%) blur(18px);
    -webkit-backdrop-filter: saturate(160%) blur(18px);
    border-radius: var(--radius-pill);
    box-shadow:
        inset 0 0 0 1px rgba(20, 18, 28, 0.06),
        0 12px 28px -16px rgba(20, 18, 28, 0.18);
    transition: box-shadow 0.5s ease, background-color 0.4s ease, border-radius 0.35s var(--ease-out-expo), padding 0.35s var(--ease-out-expo);
}

.header.is-on-dark {
    background-color: rgba(20, 18, 28, 0.35);
    box-shadow:
        inset 0 0 0 1px rgba(255, 255, 255, 0.1),
        0 12px 28px -16px rgba(20, 18, 28, 0.4);
}

.logo {
    display: flex;
    align-items: center;
    height: 2rem;
    flex-shrink: 0;
    position: relative;
    z-index: 2;
    filter: none;
}

.logo img {
    height: 2rem;
    width: auto;
    display: block;
}

.intro .logo img {
    filter: none;
}

.menu {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.menu a {
    position: relative;
    font-family: var(--font-body);
    font-weight: 500;
    font-size: 0.92rem;
    color: var(--ink);
    padding: 0.55em 0.95em;
    border-radius: var(--radius-pill);
    transition: color 0.3s ease, background-color 0.3s ease;
}

.menu a:hover {
    background-color: color-mix(in srgb, var(--purple) 12%, transparent);
    color: var(--purple-deep);
}

.menu a.is-selected {
    background-color: var(--ink);
    color: var(--paper-soft);
}

.header .icons {
    display: none;
}

.burger {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 2.4rem;
    width: 2.4rem;
    border-radius: 999px;
    background-color: var(--ink);
    color: var(--paper-soft);
    gap: 4px;
    padding: 0;
    margin-left: auto;
}

.burger div {
    background-color: currentColor;
    height: 2px;
    width: 16px;
    border-radius: 2px;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav .buttons {
    font-size: 0.82rem;
}

@media screen and (max-width: 999px) {
    .header {
        flex-wrap: wrap;
        padding: 0.75rem 1rem 0.75rem 1.25rem;
    }

    .header:has(.nav.is-open) {
        border-radius: var(--radius-lg);
        padding: 0.75rem 1rem 1.1rem 1.25rem;
        background-color: rgba(255, 253, 247, 0.92);
        box-shadow:
            inset 0 0 0 1px rgba(20, 18, 28, 0.08),
            0 24px 48px -20px rgba(20, 18, 28, 0.22);
    }

    .burger {
        display: inline-flex;
        transition: background-color 0.3s ease, transform 0.3s var(--ease-out-expo);
    }

    .header:has(.nav.is-open) .burger {
        background-color: var(--purple);
    }

    .header:has(.nav.is-open) .burger div:nth-child(1) {
        transform: translateY(6px) rotate(45deg);
    }

    .header:has(.nav.is-open) .burger div:nth-child(2) {
        opacity: 0;
        transform: scaleX(0.4);
    }

    .header:has(.nav.is-open) .burger div:nth-child(3) {
        transform: translateY(-6px) rotate(-45deg);
    }

    .nav {
        order: 3;
        width: 100%;
        flex-direction: column;
        align-items: stretch;
        gap: 0.75rem;
        padding: 0.75rem 0 0;
        margin-top: 0.5rem;
        border-top: 1px solid color-mix(in srgb, var(--ink) 8%, transparent);
    }

    .nav:not(.is-open) {
        display: none;
    }

    .menu {
        flex-direction: column;
        align-items: stretch;
        width: 100%;
        gap: 0.125rem;
    }

    .menu li {
        list-style: none;
    }

    .menu a {
        display: block;
        text-align: left;
        padding: 0.85rem 1rem;
        border-radius: var(--radius-md);
        font-size: 1.02rem;
        font-weight: 500;
        line-height: 1.3;
        color: var(--ink);
    }

    .menu a:hover,
    .menu a:focus-visible {
        background-color: color-mix(in srgb, var(--purple) 8%, transparent);
        color: var(--purple-deep);
    }

    .menu a.is-selected {
        background-color: var(--ink);
        color: var(--paper-soft);
    }

    .nav .buttons {
        width: 100%;
        font-size: 0.95rem;
        padding-top: 0.25rem;
    }

    .nav .buttons .button {
        width: 100%;
        text-align: center;
        padding-top: 0.95rem;
        padding-bottom: 0.95rem;
    }
}

@media screen and (min-width: 1000px) {
    .header {
        left: 1.5rem;
        right: 1.5rem;
        padding: 0.875rem 1.25rem 0.875rem 1.5rem;
        margin: 1rem auto;
        max-width: calc(var(--container-max-width) - 1rem);
    }

    .nav {
        gap: 1.25rem;
    }

    .menu {
        gap: 0.25rem;
    }
}