/* ── Sidebar Navigation ─────────────────────────────────────────────── */
:root {
    --sidebar-width: 240px;
    --sidebar-collapsed-width: 56px;
    --sidebar-bg: #1a1a2e;
    --sidebar-hover: rgba(255,255,255,0.08);
    --sidebar-active: rgba(255,255,255,0.14);
    --sidebar-text: #a0c4ff;
    --sidebar-text-active: #fff;
    --sidebar-divider: rgba(255,255,255,0.08);
    --topbar-height: 48px;
}

/* ── Sidebar ─────────────────────────────────────────────────────────── */
.sidebar {
    position: fixed; top: 0; left: 0; bottom: 0;
    width: var(--sidebar-width);
    background: var(--sidebar-bg);
    z-index: 1000;
    display: flex; flex-direction: column;
    transition: width 0.2s ease;
    overflow: hidden;
}
.sidebar.collapsed { width: var(--sidebar-collapsed-width); }

/* Brand */
.sb-brand {
    display: flex; align-items: center; gap: 10px;
    padding: 14px 16px; text-decoration: none; color: #fff;
    border-bottom: 1px solid var(--sidebar-divider);
    flex-shrink: 0; min-height: 52px;
}
.sb-brand img { height: 28px; width: auto; object-fit: contain; flex-shrink: 0; }
.sb-brand-text { font-size: 1.05rem; font-weight: 700; white-space: nowrap; overflow: hidden; }
.sidebar.collapsed .sb-brand-text { display: none; }

/* Nav items */
.sb-nav { flex: 1; overflow-y: auto; padding: 8px 0; display: flex; flex-direction: column; }
.sb-nav::-webkit-scrollbar { width: 4px; }
.sb-nav::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.15); border-radius: 2px; }

.sb-item {
    display: flex; align-items: center; gap: 10px;
    padding: 9px 16px; margin: 1px 8px;
    border-radius: 6px; color: var(--sidebar-text);
    text-decoration: none; font-size: 0.84rem;
    transition: background 0.12s, color 0.12s;
    white-space: nowrap; cursor: pointer;
    border: none; background: none; width: calc(100% - 16px);
    text-align: left;
}
.sb-item:hover { background: var(--sidebar-hover); color: var(--sidebar-text-active); }
.sb-item.active { background: var(--sidebar-active); color: var(--sidebar-text-active); font-weight: 600; }
.sb-item .sb-icon { font-size: 1rem; width: 20px; text-align: center; flex-shrink: 0; }
.sb-item .sb-label { overflow: hidden; text-overflow: ellipsis; }
.sidebar.collapsed .sb-label { display: none; }
.sidebar.collapsed .sb-item { justify-content: center; padding: 9px 0; margin: 1px 4px; }

/* Section headers */
.sb-section {
    font-size: 0.62rem; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.06em; color: rgba(255,255,255,0.35);
    padding: 16px 16px 4px 16px; white-space: nowrap;
}
.sidebar.collapsed .sb-section { display: none; }

/* Divider */
.sb-divider { height: 1px; background: var(--sidebar-divider); margin: 8px 16px; }
.sidebar.collapsed .sb-divider { margin: 8px 4px; }

/* Sub-items (collapsible groups) */
.sb-group-items { display: none; padding-left: 12px; }
.sb-group.open > .sb-group-items { display: block; }
.sb-group-btn { position: relative; }
.sb-group-btn .sb-caret {
    font-size: 0.5rem; margin-left: auto; opacity: 0.5;
    transition: transform 0.15s;
}
.sb-group.open > .sb-group-btn .sb-caret { transform: rotate(180deg); }
.sidebar.collapsed .sb-caret { display: none; }
.sidebar.collapsed .sb-group-items { display: none !important; }

/* Collapse toggle */
.sb-collapse-btn {
    display: flex; align-items: center; justify-content: center;
    padding: 10px 16px; border: none; background: none;
    color: rgba(255,255,255,0.4); cursor: pointer;
    font-size: 1rem; border-top: 1px solid var(--sidebar-divider);
    flex-shrink: 0; width: 100%;
    transition: color 0.12s;
}
.sb-collapse-btn:hover { color: rgba(255,255,255,0.7); }

/* Badge on sidebar items */
.sb-badge {
    background: #dc3545; color: #fff; font-size: 0.6rem; font-weight: 700;
    min-width: 16px; height: 16px; border-radius: 8px;
    display: inline-flex; align-items: center; justify-content: center;
    margin-left: auto; padding: 0 4px; line-height: 1;
}
.sidebar.collapsed .sb-badge { display: none; }

/* ── Top Bar ─────────────────────────────────────────────────────────── */
.topbar {
    position: fixed; top: 0; right: 0;
    left: var(--sidebar-width);
    height: var(--topbar-height);
    background: #fff; border-bottom: 1px solid #e5e7eb;
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 20px; z-index: 999;
    transition: left 0.2s ease;
}
.sidebar.collapsed ~ .topbar { left: var(--sidebar-collapsed-width); }

.topbar-left { display: flex; align-items: center; gap: 8px; }
.topbar-right { display: flex; align-items: center; gap: 6px; }

.topbar-hamburger {
    display: none; background: none; border: none; font-size: 1.3rem;
    cursor: pointer; color: #333; padding: 4px 8px;
}

/* Search / Bell / Avatar in topbar */
.tb-icon-btn {
    display: flex; align-items: center; justify-content: center;
    width: 36px; height: 36px; border-radius: 50%; border: none;
    background: none; color: #555; font-size: 1.05rem; cursor: pointer;
    transition: background 0.12s; position: relative;
}
.tb-icon-btn:hover { background: #f3f4f6; color: #333; }

/* Avatar */
.tb-avatar {
    display: flex; align-items: center; justify-content: center;
    width: 32px; height: 32px; border-radius: 50%;
    font-size: 0.7rem; font-weight: 700; cursor: pointer;
    border: 2px solid #e5e7eb; transition: border-color 0.15s;
    letter-spacing: 0.5px; user-select: none;
}
.tb-avatar:hover { border-color: #999; }

/* User dropdown from topbar */
.tb-user-dropdown { position: relative; }
.tb-user-menu {
    display: none; position: absolute; top: 100%; right: 0;
    margin-top: 4px; z-index: 10002;
}
.tb-user-dropdown.open > .tb-user-menu { display: block; }
.tb-user-menu-inner {
    background: #fff; border: 1px solid #e0e0e0; border-radius: 8px;
    min-width: 220px; box-shadow: 0 8px 24px rgba(0,0,0,0.15); overflow: hidden;
}
.tb-user-menu a {
    display: flex; align-items: center; gap: 8px; padding: 10px 16px;
    font-size: 0.84rem; color: #333; text-decoration: none; transition: background 0.12s;
}
.tb-user-menu a:hover { background: #f5f7fa; }
.tb-user-menu .ud-logout { color: #dc3545; }

/* ── Main Content Offset ─────────────────────────────────────────────── */
.main-content {
    margin-left: var(--sidebar-width);
    padding-top: var(--topbar-height);
    transition: margin-left 0.2s ease;
    min-height: 100vh;
}
.sidebar.collapsed ~ .main-content { margin-left: var(--sidebar-collapsed-width); }

/* ── Mobile ──────────────────────────────────────────────────────────── */
@media (max-width: 900px) {
    .sidebar {
        transform: translateX(-100%);
        width: var(--sidebar-width) !important;
        z-index: 10001;
    }
    .sidebar.mobile-open { transform: translateX(0); }
    .sidebar-overlay {
        display: none; position: fixed; inset: 0;
        background: rgba(0,0,0,0.4); z-index: 10000;
    }
    .sidebar.mobile-open ~ .sidebar-overlay { display: block; }
    .topbar { left: 0 !important; }
    .topbar-hamburger { display: block; }
    .main-content { margin-left: 0 !important; }
}

@media print {
    .sidebar, .topbar, .sidebar-overlay { display: none !important; }
    .main-content { margin-left: 0 !important; padding-top: 0 !important; }
}