.site-header {
    position: sticky;
    top: 0;
    z-index: 80;

    border-bottom: 1px solid var(--color-border);
    background: var(--color-canvas);

    box-shadow: var(--shadow-md);
    transition: background 240ms ease, box-shadow 240ms ease, transform 240ms ease;
}

/* Smooth header transform when scrolling */
.site-header.is-scrolled {
    background: linear-gradient(180deg, rgba(17,24,39,0.96), rgba(17,24,39,0.96));
    box-shadow: 0 8px 30px rgba(0,0,0,0.5);
}

.site-header .primary-header {
    transition: padding 220ms ease, min-height 220ms ease;
}

.site-header.is-scrolled .primary-header {
    padding-block: 8px;
    min-height: 64px;
}

.site-header.is-scrolled .brand__mark {
    width: 40px;
    height: 40px;
    box-shadow: 0 6px 18px rgba(0,0,0,0.35);
}

    .header-top {
    border-bottom: 1px solid var(--color-border);
    background: var(--color-surface);
    color: var(--color-ink);
}

    .header-top__inner {
        display: flex;
        align-items: center;
        justify-content: space-between;
        gap: 18px;
        min-height: 38px;
    }

    .header-top__message {
    color: var(--color-ink);
}

    .header-top__nav {
    display: flex;
    align-items: center;
    gap: 16px;
}

.header-top__nav a {
    color: var(--color-muted);
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    transition: background 160ms ease, color 160ms ease;
}

.header-top__nav a:hover {
    color: var(--color-accent);
    background: rgba(51, 102, 153, 0.1);
}

    .primary-header {
        display: grid;
        grid-template-columns: auto minmax(260px, 1fr) auto auto;
        align-items: center;
        gap: 18px;
        min-height: 82px;
        padding-block: 14px;
    }

    .brand {
        display: inline-flex;
        align-items: center;
        gap: 12px;
        min-width: max-content;
    }

    .brand:hover {
        color: inherit;
    }

    .brand__mark {
    display: inline-grid;
    place-items: center;
    width: 46px;
    height: 46px;
    border-radius: var(--radius-sm);

    background: linear-gradient(135deg,
        var(--color-accent),
        var(--color-accent-strong));

    color: white;
    font-weight: 900;

    box-shadow:
        0 0 18px rgba(59,130,246,.25),
        var(--shadow-sm);
}

    .brand__text {
        display: grid;
        gap: 2px;
    }

    .brand__name {
        color: var(--color-ink);
        font-size: 1.08rem;
        font-weight: 900;
        line-height: 1.1;
    }

    .brand__tagline {
        color: var(--color-muted);
        font-size: 0.82rem;
    }

    .header-search {
    display: grid;
    grid-template-columns: minmax(0,1fr) auto;
    align-items: center;

    width: min(100%,620px);
    justify-self: center;

    background: var(--color-panel);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);

    overflow: hidden;

    transition: .2s;
}

    .header-search:focus-within {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 4px rgba(59,130,246,.18);
}

    .header-search input {
        color: var(--color-ink);
        min-height: 44px;
        border: 0;
        border-radius: 0;
        background: transparent;
        box-shadow: none;
    }
    .header-search input::placeholder {
    color: var(--color-muted);
}

    .header-search input:focus {
        box-shadow: none;
    }

    .header-search button {
        min-height: 44px;
        padding: 0 18px;
        border: 0;
        border-left: 1px solid var(--color-border);
        background: var(--color-accent);
        color: #ffffff;
        font-weight: 800;
        transition: background 160ms ease;
    }

    .header-search button:hover {
        background: var(--color-accent-strong);
    }

    .account-nav {
        display: flex;
        align-items: center;
        justify-content: flex-end;
        gap: 12px;
        min-width: max-content;
    }

    .account-nav__link {
        position: relative;
        display: inline-flex;
        align-items: center;
        gap: 6px;
        color: var(--color-ink);
        font-size: 0.92rem;
        font-weight: 800;
    }

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

    .account-nav__link--strong {
        color: var(--color-accent);
    }

    .nav-count {
    min-width: 22px;
    height: 22px;

    background: var(--color-ruby);
    color: white;

    font-size: .72rem;
    border-radius: 999px;
}

    .mobile-menu-toggle {
        display: none;
        width: 44px;
        height: 44px;
        border: 1px solid var(--color-border);
        border-radius: var(--radius-sm);
        background: var(--color-panel);
        place-items: center;
        gap: 4px;
        padding: 10px;
    }
    .mobile-menu-toggle:hover {
    background: #263244;
}

    .mobile-menu-toggle__line {
        display: block;
        width: 20px;
        height: 2px;
        border-radius: 999px;
        background: var(--color-ink);
    }

    .main-nav {
    border-top: 1px solid var(--color-border);
    background: #172033;
}

    .main-nav__inner {
        display: flex;
        align-items: center;
        gap: 4px;
        min-height: 48px;
        overflow-x: auto;
        scrollbar-width: thin;
    }

    .nav-link {
        display: inline-flex;
        align-items: center;
        min-height: 38px;
        padding: 8px 12px;
        border-radius: var(--radius-sm);
        color: var(--color-text);
        font-size: 0.92rem;
        font-weight: 800;
        white-space: nowrap;
        transition: background 160ms ease, color 160ms ease;
    }

    .nav-link:hover {
    background: rgba(59,130,246,.15);
    color: var(--color-accent);
}

    .nav-link.is-active {
    background: linear-gradient(
        135deg,
        var(--color-accent),
        var(--color-accent-strong)
    );

    color: white;

    box-shadow: 0 0 16px rgba(59,130,246,.25);
}

    .nav-link.is-active:hover {
        color: #ffffff;
    }

    .page-auth .site-header,
    .page-admin .site-header {
        position: static;
    }

    .page-admin .header-top,
    .page-admin .main-nav,
    .page-admin .account-nav,
    .page-admin .mobile-menu-toggle {
        display: none;
    }

    .page-admin .primary-header {
        grid-template-columns: auto 1fr;
        min-height: 64px;
    }

    .page-admin .brand__tagline {
        display: none;
    }

    @media (max-width: 1040px) {
        .primary-header {
            grid-template-columns: auto 1fr auto;
        }

        .header-search {
            grid-column: 1 / -1;
            grid-row: 2;
            width: 100%;
        }

        .account-nav {
            grid-column: 2;
            justify-self: end;
        }

        .mobile-menu-toggle {
            display: grid;
            grid-column: 3;
        }

        .main-nav__inner {
            display: none;
            align-items: stretch;
            flex-direction: column;
            padding-block: 10px;
            overflow: visible;
        }

        .site-header.is-menu-open .main-nav__inner {
            display: flex;
        }

        .nav-link {
            width: 100%;
            justify-content: space-between;
        }
    }

    @media (max-width: 760px) {
        .header-top__inner {
            justify-content: center;
            text-align: center;
        }

        .header-top__nav {
            display: none;
        }

        .primary-header {
            grid-template-columns: 1fr auto;
            gap: 12px;
            min-height: auto;
            padding-block: 12px;
        }

        .brand {
            min-width: 0;
        }

        .brand__mark {
            width: 40px;
            height: 40px;
        }

        .brand__name {
            font-size: 1rem;
        }

        .brand__tagline {
            display: none;
        }

        .account-nav {
            grid-column: 1 / -1;
            justify-content: space-between;
            width: 100%;
            gap: 10px;
            overflow-x: auto;
            padding-top: 4px;
        }

        .account-nav__link {
            white-space: nowrap;
        }

        .mobile-menu-toggle {
            grid-column: 2;
            grid-row: 1;
        }

        .header-search {
            grid-column: 1 / -1;
            grid-row: 3;
        }

        .header-search button {
            padding-inline: 14px;
        }

        .page-admin .primary-header {
            grid-template-columns: 1fr;
        }
    }