/*
 * Site header and navigation — modern, responsive.
 *
 * Desktop: horizontal nav with brand, links, language, and auth buttons.
 * Mobile: hamburger menu with slide-down panel.
 */

/* ---- Header container ----------------------------------------------------------------------- */

.site-header {
    position: sticky;
    top: 0;
    z-index: var(--layer-header);
    background: var(--colour-surface);
    border-bottom: 1px solid var(--colour-border);
    backdrop-filter: blur(8px);
    background: color-mix(in srgb, var(--colour-surface) 85%, transparent);
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-4);
    max-width: var(--page-width);
    margin: 0 auto;
    padding: var(--space-3) var(--gutter);
    min-height: 64px;
}

/* ---- Brand ---------------------------------------------------------------------------------- */

.site-header__brand {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    text-decoration: none;
    color: var(--colour-ink);
    font-weight: var(--weight-bold);
    font-size: var(--text-lg);
}

.site-header__logo {
    width: 3.6rem;
    height: 3.6rem;
    border-radius: var(--radius-sm);
    object-fit: cover;
    flex-shrink: 0;
}

.site-header__name {
    white-space: nowrap;
}

/* ---- Desktop navigation --------------------------------------------------------------------- */

.site-nav__list {
    display: flex;
    align-items: center;
    gap: var(--space-1);
    list-style: none;
    margin: 0;
    padding: 0;
}

.site-nav__link {
    display: inline-flex;
    align-items: center;
    padding: var(--space-2) var(--space-3);
    text-decoration: none;
    color: var(--colour-ink-quiet);
    font-weight: var(--weight-medium);
    font-size: var(--text-sm);
    border-radius: var(--radius-md);
    transition: color var(--duration-fast) var(--easing),
                background var(--duration-fast) var(--easing);
}

.site-nav__link:hover {
    color: var(--colour-ink);
    background: var(--colour-surface-sunken);
}

.site-nav__link--active,
.site-nav__link[aria-current="page"] {
    color: var(--colour-primary);
    background: var(--colour-primary-surface);
}

/* The notifications link carries a count, so the word and the badge are one target with a gap between them
   rather than two things that happen to be adjacent. The link is a flex row already; this only names the
   spacing, so that a link with nothing unread is exactly as wide as it was before the badge existed. */
.site-nav__link--notifications {
    gap: var(--space-2);
}

/* The badge is rendered even at zero, with `hidden` on it, so the script has somewhere to put a count it
   learns about later. `hidden` must win: without this, the display value here would override it and every
   reader with nothing unread would see an empty pill. */
.site-nav__badge[hidden] {
    display: none;
}

/* ---- Header actions ------------------------------------------------------------------------- */

.site-header__actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

/* ---- User menu (authenticated) -------------------------------------------------------------- */

.user-menu {
    position: relative;
}

.user-menu__toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    padding: 0;
    background: var(--colour-primary);
    color: var(--colour-primary-ink);
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    font-weight: var(--weight-bold);
    font-size: var(--text-sm);
    transition: background var(--duration-fast) var(--easing);
}

.user-menu__toggle:hover {
    background: var(--colour-primary-hover);
}

.user-menu__avatar {
    line-height: 1;
}

/* A stored picture fills the whole toggle circle in place of the generated initial. */
img.user-menu__avatar--image {
    display: block;
    width: 100%;
    height: 100%;
    border-radius: var(--radius-full);
    object-fit: cover;
}

.user-menu__dropdown {
    position: absolute;
    top: calc(100% + var(--space-2));
    right: 0;
    min-width: 200px;
    background: var(--colour-surface-overlay);
    border: 1px solid var(--colour-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    padding: var(--space-1);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity var(--duration-fast) var(--easing),
                visibility var(--duration-fast) var(--easing),
                transform var(--duration-fast) var(--easing);
}

.user-menu[aria-open="true"] .user-menu__dropdown,
.user-menu__toggle[aria-expanded="true"] + .user-menu__dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.user-menu__item {
    display: block;
    width: 100%;
    padding: var(--space-2) var(--space-3);
    text-decoration: none;
    color: var(--colour-ink);
    font-size: var(--text-sm);
    border-radius: var(--radius-sm);
    text-align: left;
    background: none;
    border: none;
    cursor: pointer;
}

.user-menu__item:hover {
    background: var(--colour-surface-sunken);
}

.user-menu__item--button {
    color: var(--colour-error);
}

.user-menu__divider {
    margin: var(--space-1) 0;
    border: none;
    border-top: 1px solid var(--colour-border);
}

/* ---- Mobile menu toggle --------------------------------------------------------------------- */

.mobile-menu-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    padding: 0;
    background: none;
    border: none;
    color: var(--colour-ink);
    cursor: pointer;
    border-radius: var(--radius-md);
}

.mobile-menu-toggle:hover {
    background: var(--colour-surface-sunken);
}

/* ---- Mobile menu panel ---------------------------------------------------------------------- */

.mobile-menu {
    display: none;
    background: var(--colour-surface);
    border-top: 1px solid var(--colour-border);
    padding: var(--space-3) var(--gutter);
}

.mobile-menu[hidden] {
    display: none;
}

.mobile-menu__list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.mobile-menu__link {
    display: block;
    padding: var(--space-3) var(--space-4);
    text-decoration: none;
    color: var(--colour-ink);
    font-weight: var(--weight-medium);
    border-radius: var(--radius-md);
}

.mobile-menu__link:hover {
    background: var(--colour-surface-sunken);
}

.mobile-menu__link--cta {
    background: var(--colour-primary);
    color: var(--colour-primary-ink);
    text-align: center;
    margin-top: var(--space-2);
}

.mobile-menu__link--cta:hover {
    background: var(--colour-primary-hover);
}

/* ---- Responsive ----------------------------------------------------------------------------- */

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

    .mobile-menu-toggle {
        display: flex;
    }

    .mobile-menu {
        display: block;
    }

    .site-header__actions .btn {
        display: none;
    }

    .lang-select {
        display: none;
    }
}

@media (min-width: 769px) {
    .mobile-menu {
        display: none !important;
    }
}