.site-header {
    position: sticky;
    top: 0;
    z-index: 100;

    background: rgba(242, 246, 241, 0.82);
    backdrop-filter: blur(16px) saturate(140%);
    -webkit-backdrop-filter: blur(16px) saturate(140%);
    border-bottom: var(--border-width) solid rgba(20, 38, 28, 0.07);
    transition: background var(--transition-base), border-color var(--transition-base);
}

@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
    .site-header { background: var(--color-parchment-dim); }
}

.navbar {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--space-3) var(--space-6);
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: var(--space-6);
}

.navbar-logo {
    height: 36px;
    width: auto;
    display: block;
}

.brand {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-family: var(--font-display);
    font-size: var(--text-lg);
    font-weight: 600;
}

.navbar .brand { justify-self: start; }

.navbar .nav-links {
    justify-self: center;
    display: flex;
    align-items: center;
    gap: var(--space-6);
}

.navbar .navbar-right {
    justify-self: end;
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.navbar .nav-user {
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-ink-soft);
}
.nav-links a {
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-ink-mid);
    position: relative;
    padding-bottom: 5px;
    white-space: nowrap;
    transition: color var(--transition-fast);
}

.nav-links a:hover { color: var(--color-ink); }

.nav-links a.active,
.nav-links a[aria-current="page"] {
    color: var(--color-sage-deep);
    font-weight: 600;
}

.nav-links a::after {
    content: '';
    position: absolute;
    left: 50%;
    bottom: 0;
    width: 0;
    height: 1.5px;
    border-radius: 2px;
    background: var(--color-sage);
    transition: width var(--transition-base);
    transform: translateX(-50%);
}

.nav-links a:hover::after,
.nav-links a.active::after,
.nav-links a[aria-current="page"]::after { width: 100%; }

.nav-links .nav-cta::after,
.nav-links .nav-signin::after { display: none; }
.nav-cta {
    display: inline-flex;
    align-items: center;
    border: var(--border-width) solid var(--color-sage);
    color: var(--color-sage-deep);
    background: transparent;
    padding: 7px 16px;
    border-radius: 999px;
    font-size: var(--text-sm);
    font-weight: 500;
    white-space: nowrap;
    transition: background var(--transition-fast), color var(--transition-fast),
                border-color var(--transition-fast);
}

.nav-cta:hover {
    background: var(--color-sage);
    border-color: var(--color-sage);
    color: var(--color-white);
}

.nav-signin {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    border: var(--border-width) solid var(--color-sage);
    padding: 7px 16px;
    border-radius: 999px;
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-sage-deep);
    background: transparent;
    transition: background var(--transition-fast), color var(--transition-fast),
                border-color var(--transition-fast);
}

.nav-signin:hover {
    background: var(--color-sage);
    border-color: var(--color-sage);
    color: var(--color-white);
}

.nav-signin svg { width: 19px; height: 19px; }

.nav-toggle { display: none; }

.site-header--overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: transparent;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    border-bottom-color: transparent;
}

.site-header--overlay .nav-links a,
.site-header--overlay .nav-signin,
.site-header--overlay .nav-user {
    color: var(--color-white);
}

/* On the hero the bar has no background, so links get more weight, size and
   a soft shadow to stay readable. The scrolled state below resets this. */
.site-header--overlay .nav-links a,
.site-header--overlay .nav-cta,
.site-header--overlay .nav-signin {
    font-size: var(--text-base);
    font-weight: 600;
}

.site-header--overlay .nav-links a:hover {
    color: var(--color-white);
    background: transparent;
}

.site-header--overlay .nav-links a.active,
.site-header--overlay .nav-links a[aria-current="page"] { color: var(--color-white); }

.site-header--overlay .nav-links a::after { background: var(--color-white); }

.site-header--overlay .nav-cta {
    border-color: rgba(255, 255, 255, 0.65);
    color: var(--color-white);
}

.site-header--overlay .nav-cta:hover {
    background: var(--color-white);
    border-color: var(--color-white);
    color: var(--color-sage-deep);
}

.site-header--overlay .nav-signin {
    border-color: rgba(255, 255, 255, 0.65);
    color: var(--color-white);
}

.site-header--overlay .nav-signin:hover {
    background: var(--color-white);
    border-color: var(--color-white);
    color: var(--color-sage-deep);
}

.site-header--overlay .nav-toggle path { stroke: var(--color-white); }

.site-header--overlay.is-scrolled {
    background: rgba(242, 246, 241, 0.82);
    backdrop-filter: blur(16px) saturate(140%);
    -webkit-backdrop-filter: blur(16px) saturate(140%);
    border-bottom-color: rgba(20, 38, 28, 0.07);
}

.site-header--overlay.is-scrolled .nav-links a,
.site-header--overlay.is-scrolled .nav-cta,
.site-header--overlay.is-scrolled .nav-signin {
    font-size: var(--text-sm);
    font-weight: 500;
    text-shadow: none;
}

.site-header--overlay.is-scrolled .nav-links a { color: var(--color-ink-mid); }

.site-header--overlay.is-scrolled .nav-user { color: var(--color-ink-soft); }

.site-header--overlay.is-scrolled .nav-links a:hover { color: var(--color-ink); }

.site-header--overlay.is-scrolled .nav-links a.active,
.site-header--overlay.is-scrolled .nav-links a[aria-current="page"] { color: var(--color-sage-deep); }

.site-header--overlay.is-scrolled .nav-links a::after { background: var(--color-sage); }

.site-header--overlay.is-scrolled .nav-cta {
    border-color: var(--color-sage);
    color: var(--color-sage-deep);
}

.site-header--overlay.is-scrolled .nav-cta:hover {
    background: var(--color-sage);
    color: var(--color-white);
}

.site-header--overlay.is-scrolled .nav-signin {
    border-color: var(--color-sage);
    color: var(--color-sage-deep);
}

.site-header--overlay.is-scrolled .nav-signin:hover {
    background: var(--color-sage);
    color: var(--color-white);
}

.site-header--overlay.is-scrolled .nav-toggle path { stroke: var(--color-ink); }

/* About dropdown. The trigger is a span, not a link, so it cannot be clicked.
   The menu opens on hover and on keyboard focus within the group. */
.nav-dropdown {
    position: relative;
    display: inline-flex;
    align-items: center;
}

.nav-dropdown__trigger {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding-bottom: 5px;
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-ink-mid);
    cursor: default;
    white-space: nowrap;
    transition: color var(--transition-fast);
}

.nav-dropdown__trigger.active { color: var(--color-sage-deep); font-weight: 600; }

.nav-dropdown:hover .nav-dropdown__trigger,
.nav-dropdown:focus-within .nav-dropdown__trigger { color: var(--color-ink); }

.nav-dropdown__caret { transition: transform var(--transition-fast); }

.nav-dropdown:hover .nav-dropdown__caret,
.nav-dropdown:focus-within .nav-dropdown__caret { transform: rotate(180deg); }

.nav-dropdown__menu {
    position: absolute;
    top: 100%;
    left: 50%;
    margin-top: 8px;
    transform: translateX(-50%);
    min-width: 200px;
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: var(--space-3);
    background: var(--color-white);
    border: var(--border-width) solid var(--color-border);
    border-radius: var(--radius-card);
    box-shadow: var(--shadow-lift);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-fast), visibility var(--transition-fast);
    z-index: 120;
}

/* Transparent bridge so moving the pointer from trigger to menu keeps hover. */
.nav-dropdown__menu::before {
    content: '';
    position: absolute;
    top: -10px;
    left: 0;
    right: 0;
    height: 10px;
}

.nav-dropdown:hover .nav-dropdown__menu,
.nav-dropdown:focus-within .nav-dropdown__menu {
    opacity: 1;
    visibility: visible;
}

.nav-dropdown__menu a {
    display: block;
    padding: 9px 12px;
    border-radius: 8px;
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-ink-mid);
    white-space: nowrap;
}

.nav-dropdown__menu a::after { display: none; }

.nav-dropdown__menu a:hover {
    background: var(--color-sage-tint);
    color: var(--color-sage-deep);
}

/* Overlay (hero) variant: the trigger matches the other overlay links; the
   menu keeps its own light card in both states. */
.site-header--overlay .nav-dropdown__trigger {
    color: var(--color-white);
    font-size: var(--text-base);
    font-weight: 600;
    text-shadow: 0 1px 3px rgba(12, 26, 18, 0.55);
}

/* Keep the trigger white on the hero; the base hover rule would hide it. */
.site-header--overlay .nav-dropdown:hover .nav-dropdown__trigger,
.site-header--overlay .nav-dropdown:focus-within .nav-dropdown__trigger {
    color: var(--color-white);
}

.site-header--overlay.is-scrolled .nav-dropdown__trigger {
    color: var(--color-ink-mid);
    font-size: var(--text-sm);
    font-weight: 500;
    text-shadow: none;
}

/* Once scrolled the bar is light again, so hover returns to dark ink. */
.site-header--overlay.is-scrolled .nav-dropdown:hover .nav-dropdown__trigger,
.site-header--overlay.is-scrolled .nav-dropdown:focus-within .nav-dropdown__trigger {
    color: var(--color-ink);
}

.site-header--overlay.is-scrolled .nav-dropdown__trigger.active {
    color: var(--color-sage-deep);
    font-weight: 600;
}

/* The menu is a light card, so its links skip the overlay treatment. */
.site-header--overlay .nav-dropdown__menu a {
    color: var(--color-ink-mid);
    font-size: var(--text-sm);
    font-weight: 500;
    text-shadow: none;
}

.site-header--overlay .nav-dropdown__menu a:hover {
    color: var(--color-sage-deep);
}

@media (max-width: 860px) {
    .navbar {
        grid-template-columns: auto auto;
        justify-content: space-between;
        row-gap: 0;
    }

    .navbar .brand {
        grid-row: 1;
        grid-column: 1;
    }

    .navbar .navbar-right {
        grid-row: 1;
        grid-column: 2;
        justify-self: end;
    }

    .nav-toggle { display: block; }

    .navbar .nav-links { display: none; }

    .navbar .nav-links.is-open {
        display: flex;
        flex-direction: column;
        align-items: flex-start;
        gap: var(--space-4);
        grid-row: 2;
        grid-column: 1 / -1;
        width: 100%;
        padding: var(--space-5) 0 var(--space-2);
        margin-top: var(--space-4);
        border-top: var(--border-width) solid var(--color-border);
    }

    /* No hover in the mobile drawer, so About shows inline under its trigger. */
    .nav-dropdown {
        display: block;
        width: 100%;
    }

    .nav-dropdown__caret { display: none; }

    .nav-dropdown__menu {
        position: static;
        transform: none;
        margin-top: var(--space-2);
        min-width: 0;
        padding: 0 0 0 var(--space-4);
        background: transparent;
        border: none;
        box-shadow: none;
        opacity: 1;
        visibility: visible;
    }
    .main-content .message.error,
    .main-content .flash-message {
        position: relative;
        z-index: 20;
        margin-top: 200px;
    }

    .nav-dropdown__menu::before { display: none; }

    .navbar .nav-user { display: none; }

    .navbar .navbar-right .nav-signin span {
        position: absolute;
        width: 1px;
        height: 1px;
        overflow: hidden;
        clip-path: inset(50%);
        white-space: nowrap;
    }

    .navbar .navbar-right .nav-signin { padding: 8px 10px; }

    /* Icon-only on mobile, so give it more presence. */
    .navbar .navbar-right .nav-signin svg { width: 24px; height: 24px; }

    .navbar .navbar-right .nav-cta {
        padding: 8px 14px;
        font-size: var(--text-sm);
    }
}