.admin-shell {
    min-height: 100vh;
    display: flex;
    flex-direction: row;
    background: #f4f6f8;
    color: #111827;
    font-family: "Segoe UI", Tahoma, Arial, sans-serif;
}

body.admin-shell {
    margin-bottom: 0;
}

.admin-sidebar {
    width: 260px;
    min-height: 100vh;
    background: #111827;
    color: white;
    flex: 0 0 260px;
}

.admin-logo {
    padding: 24px;
    font-size: 22px;
    font-weight: 700;
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.admin-nav {
    padding: 16px;
    display: grid;
    gap: 8px;
}

.admin-nav a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    color: #d1d5db;
    text-decoration: none;
    border-radius: 8px;
    background: transparent;
    font-weight: 600;
    line-height: 1.35;
    transition: background-color 160ms ease, color 160ms ease, transform 160ms ease;
}

.admin-nav__icon {
    width: 20px;
    height: 20px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex: 0 0 20px;
    color: #9ca3af;
    font-size: 18px;
}

.admin-nav a:hover,
.admin-nav a.active {
    color: white;
    background: #1f2937;
    transform: translateX(2px);
}

.admin-nav a:hover .admin-nav__icon,
.admin-nav a.active .admin-nav__icon {
    color: white;
}

.admin-nav-group {
    min-width: 0;
}

.admin-nav-group__summary {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    color: #d1d5db;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 700;
    list-style: none;
    transition: background-color 160ms ease, color 160ms ease;
}

.admin-nav-group__summary::-webkit-details-marker {
    display: none;
}

.admin-nav-group__summary:hover,
.admin-nav-group[open] > .admin-nav-group__summary {
    color: #fff;
    background: #1f2937;
}

.admin-nav-group__chevron {
    margin-left: auto;
    color: #9ca3af;
    transition: transform 160ms ease;
}

.admin-nav-group[open] .admin-nav-group__chevron {
    transform: rotate(90deg);
}

.admin-nav-group__items {
    display: grid;
    gap: 4px;
    margin-top: 6px;
    padding-left: 14px;
}

.admin-nav-group__items a {
    padding: 10px 14px;
    font-size: 14px;
}

.admin-main {
    min-width: 0;
    flex: 1;
}

.admin-topbar {
    height: 64px;
    background: white;
    border-bottom: 1px solid #e5e7eb;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 0 24px;
}

.admin-topbar h1 {
    font-size: 20px;
    font-weight: 700;
    margin: 0;
}

.admin-topbar__title {
    min-width: 0;
    display: flex;
    align-items: center;
    gap: 12px;
}

.admin-back-btn {
    width: 38px;
    height: 38px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex: 0 0 38px;
    border: 1px solid #dbe4f0;
    border-radius: 8px;
    background: white;
    color: #475569;
    cursor: pointer;
    font-size: 20px;
    transition: background-color 160ms ease, border-color 160ms ease, color 160ms ease;
}

.admin-back-btn:hover {
    background: #f8fafc;
    border-color: #b7c6da;
    color: #111827;
}

.admin-back-btn i {
    font-size: 20px;
}

.admin-content {
    padding: 24px;
}

.logout-btn {
    display: inline-flex;
    align-items: center;
    background: #111827;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 8px 16px;
    cursor: pointer;
    font-weight: 700;
    text-decoration: none;
}

.logout-btn:hover {
    background: #374151;
    color: white;
}

@media (max-width: 900px) {
    .admin-shell {
        display: block;
    }

    .admin-sidebar {
        width: 100%;
        min-height: auto;
        flex: none;
    }

    .admin-nav {
        grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    }

    .admin-nav a:hover,
    .admin-nav a.active {
        transform: none;
    }
}

@media (max-width: 560px) {
    .admin-content,
    .admin-topbar {
        padding-left: 16px;
        padding-right: 16px;
    }
}