.topbar {
    position: sticky;
    top: 0;
    z-index: 60;
    backdrop-filter: blur(14px);
    background:
        linear-gradient(180deg, color-mix(in srgb, var(--surface, #17191b) 90%, transparent), color-mix(in srgb, var(--surface, #17191b) 78%, transparent)),
        radial-gradient(circle at top right, rgba(50, 144, 163, 0.18), transparent 44%);
    border-bottom: 1px solid color-mix(in srgb, var(--line, #1e2124) 85%, rgba(255, 255, 255, 0.05));
    box-shadow: 0 18px 34px rgba(0, 0, 0, 0.22);
}

.topbar-shell {
    width: 100%;
    padding: 0.78rem 1.2rem;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 1rem;
}

.topbar-left,
.topbar-right {
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.topbar-left {
    min-width: 0;
    flex: 0 0 auto;
}

.brand-link {
    display: flex;
    align-items: center;
    gap: 0.72rem;
    min-width: 0;
    text-decoration: none;
    color: var(--ink, #ebedee);
}

.brand-link:hover .brand-title {
    color: var(--accent-ink, #92dceb);
}

.brand-mark {
    width: 1.95rem;
    height: 1.95rem;
    flex: 0 0 auto;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.58rem;
    background: linear-gradient(135deg, var(--brand, #185e6c), var(--accent, #3290a3));
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.28);
    color: #ffffff;
    overflow: hidden;
}

.brand-mark svg,
.brand-mark img {
    width: 1.15rem;
    height: 1.15rem;
}

.brand-mark img {
    object-fit: cover;
}

.brand-mark-text {
    font-family: 'Sora', sans-serif;
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.brand-copy {
    min-width: 0;
    display: grid;
    gap: 0.08rem;
}

.brand-title {
    font-family: 'Sora', sans-serif;
    font-size: 1.02rem;
    font-weight: 600;
    color: var(--ink, #ebedee);
    white-space: nowrap;
}

.brand-subtitle {
    font-size: 0.76rem;
    color: var(--muted, #8f9398);
    white-space: nowrap;
}

.topbar-nav {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 0.45rem;
    flex: 1;
    min-width: 0;
    flex-wrap: wrap;
}

.topbar-right {
    margin-left: auto;
}

.topbar-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.35rem;
    min-height: 2.2rem;
    padding: 0.5rem 0.9rem;
    border: 1px solid transparent;
    border-radius: 999px;
    color: var(--muted, #8f9398);
    text-decoration: none;
    font-size: 0.86rem;
    font-weight: 600;
    line-height: 1;
    transition: color 0.15s ease, background 0.15s ease, border-color 0.15s ease;
    cursor: pointer;
}

.topbar-link:hover,
.topbar-link:focus-visible {
    outline: none;
    color: var(--ink, #ebedee);
    background: color-mix(in srgb, var(--surface-strong, #1d1f22) 78%, transparent);
    border-color: color-mix(in srgb, var(--line-strong, #2f3336) 84%, transparent);
}

.topbar-link.active,
.topbar-dropdown[open] > .topbar-link {
    color: var(--accent-ink, #92dceb);
    background: color-mix(in srgb, var(--brand, #185e6c) 24%, transparent);
    border-color: color-mix(in srgb, var(--accent, #3290a3) 58%, transparent);
}

.topbar-dropdown {
    position: relative;
}

.topbar-dropdown > summary {
    list-style: none;
}

.topbar-dropdown > summary::-webkit-details-marker {
    display: none;
}

.topbar-link-button::after {
    content: '';
    width: 0.38rem;
    height: 0.38rem;
    border-right: 1.5px solid currentColor;
    border-bottom: 1.5px solid currentColor;
    transform: rotate(45deg) translateY(-1px);
    margin-left: 0.1rem;
}

.topbar-menu {
    position: absolute;
    top: calc(100% + 0.3rem);
    left: 0;
    min-width: 12rem;
    padding: 0.4rem;
    display: grid;
    gap: 0.2rem;
    background: color-mix(in srgb, var(--surface, #17191b) 96%, rgba(0, 0, 0, 0.3));
    border: 1px solid color-mix(in srgb, var(--line, #1e2124) 90%, rgba(255, 255, 255, 0.05));
    border-radius: 0.9rem;
    box-shadow: 0 20px 36px rgba(0, 0, 0, 0.32);
}

.topbar-menu-link {
    display: block;
    padding: 0.62rem 0.72rem;
    border-radius: 0.66rem;
    color: var(--muted, #8f9398);
    text-decoration: none;
    font-size: 0.84rem;
    font-weight: 500;
}

.topbar-menu-link:hover,
.topbar-menu-link:focus-visible,
.topbar-menu-link.active {
    outline: none;
    color: var(--ink, #ebedee);
    background: color-mix(in srgb, var(--surface-strong, #1d1f22) 72%, transparent);
}

.topbar-auth-area {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    min-height: 2rem;
}

.topbar-auth-email {
    max-width: 200px;
    color: var(--muted, #8f9398);
    font-size: 0.84rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.topbar-auth-btn {
    border: 1px solid var(--line-strong, #2f3336);
    border-radius: 999px;
    background: transparent;
    color: var(--muted, #8f9398);
    font-family: inherit;
    font-size: 0.82rem;
    font-weight: 600;
    line-height: 1;
    padding: 0.52rem 0.88rem;
    cursor: pointer;
    transition: color 0.15s ease, border-color 0.15s ease, background 0.15s ease;
}

.topbar-auth-btn:hover,
.topbar-auth-btn:focus-visible {
    outline: none;
    color: var(--ink, #ebedee);
    background: color-mix(in srgb, var(--surface-strong, #1d1f22) 70%, transparent);
    border-color: var(--accent, #3290a3);
}

.header-sidebar-toggle {
    display: none;
    width: 2.25rem;
    height: 2.25rem;
    padding: 0;
    border: 1px solid var(--line-strong, #2f3336);
    border-radius: 0.7rem;
    background: color-mix(in srgb, var(--surface-strong, #1d1f22) 84%, transparent);
    color: var(--ink, #ebedee);
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

@media (max-width: 768px) {
    .topbar-shell {
        padding: 0.72rem 1rem;
        flex-wrap: wrap;
        justify-content: flex-start;
    }

    .topbar-nav {
        order: 3;
        width: 100%;
        justify-content: flex-start;
        padding-top: 0.1rem;
    }

    .topbar-right {
        margin-left: auto;
    }

    .brand-subtitle {
        display: none;
    }

    body.app-mode .header-sidebar-toggle {
        display: inline-flex;
    }
}