/* ============================================================
   LAYOUT — App Shell, Sidebar, Header, Pages
   ============================================================ */

/* ── App Shell ───────────────────────────────────────────── */
.app {
    display: flex;
    height: 100vh;
    overflow: hidden;
    background: var(--bg);
}

/* ── Sidebar ─────────────────────────────────────────────── */
.sidebar {
    width: var(--sidebar-w);
    min-width: var(--sidebar-w);
    background: var(--bg-alt);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
    transition: width var(--t-normal), min-width var(--t-normal);
    position: relative;
    flex-shrink: 0;
}
.sidebar.collapsed {
    width: var(--sidebar-w-mini);
    min-width: var(--sidebar-w-mini);
}

/* Resize handle */
.sidebar-resizer {
    position: absolute;
    right: -3px;
    top: 0;
    bottom: 0;
    width: 6px;
    cursor: col-resize;
    z-index: 10;
    background: transparent;
    transition: background var(--t-fast);
}
.sidebar-resizer:hover,
.sidebar-resizer.dragging {
    background: var(--accent);
    opacity: 0.5;
}

/* Sidebar brand */
.sidebar-brand {
    display: flex;
    align-items: center;
    gap: var(--sp-3);
    padding: var(--sp-4);
    height: var(--header-h);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    overflow: hidden;
}
.sidebar-logo {
    width: 22px;
    height: 22px;
    flex-shrink: 0;
    background: var(--accent);
    border-radius: var(--r-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 900;
    color: #000;
}
.sidebar-brand-name {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text);
    white-space: nowrap;
    overflow: hidden;
    letter-spacing: -0.02em;
    transition: opacity var(--t-normal);
}
.sidebar.collapsed .sidebar-brand-name { opacity: 0; width: 0; }

/* Sidebar nav */
.sidebar-nav {
    flex: 1;
    overflow-y: auto;
    padding: var(--sp-2) 0;
}

.nav-section {
    margin-bottom: var(--sp-2);
}
.nav-section-label {
    padding: var(--sp-2) var(--sp-3) var(--sp-1);
    font-size: var(--text-2xs);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-dim);
    white-space: nowrap;
    overflow: hidden;
    transition: opacity var(--t-normal);
}
.sidebar.collapsed .nav-section-label { opacity: 0; }

.nav-item {
    display: flex;
    align-items: center;
    gap: var(--sp-3);
    height: 36px;
    padding: 0 var(--sp-3);
    font-size: var(--text-sm);
    color: var(--text-muted);
    cursor: pointer;
    text-decoration: none;
    transition: background var(--t-fast), color var(--t-fast);
    white-space: nowrap;
    overflow: hidden;
    border-radius: 0;
    position: relative;
}
.nav-item:hover { background: var(--surface); color: var(--text); }
.nav-item.active {
    background: var(--surface);
    color: var(--accent);
    border-right: 2px solid var(--accent);
}
.nav-item-icon {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
}
.nav-item-label {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    transition: opacity var(--t-normal), width var(--t-normal);
}
.sidebar.collapsed .nav-item-label { opacity: 0; width: 0; }

.nav-item-badge {
    background: var(--accent);
    color: #000;
    font-family: var(--font-mono);
    font-size: 9px;
    font-weight: 700;
    padding: 1px 5px;
    border-radius: var(--r-pill);
    transition: opacity var(--t-normal);
}
.sidebar.collapsed .nav-item-badge { opacity: 0; }

/* Tooltip on collapsed sidebar */
.sidebar.collapsed .nav-item:hover::after {
    content: attr(data-label);
    position: absolute;
    left: calc(var(--sidebar-w-mini) + 8px);
    background: var(--surface);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: var(--r-md);
    padding: var(--sp-1) var(--sp-2);
    font-size: var(--text-sm);
    white-space: nowrap;
    z-index: 100;
    box-shadow: 0 4px 12px rgba(0,0,0,0.25);
    pointer-events: none;
}

/* Sidebar footer */
.sidebar-footer {
    border-top: 1px solid var(--border);
    padding: var(--sp-3);
    flex-shrink: 0;
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    overflow: hidden;
}
.sidebar-user-name {
    flex: 1;
    font-size: var(--text-sm);
    font-weight: 500;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    transition: opacity var(--t-normal);
}
.sidebar.collapsed .sidebar-user-name { opacity: 0; width: 0; }

/* Sidebar collapse toggle */
.sidebar-toggle {
    position: absolute;
    right: -12px;
    top: 50%;
    transform: translateY(-50%);
    width: 24px;
    height: 24px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 20;
    font-size: 10px;
    color: var(--text-muted);
    transition: color var(--t-fast), background var(--t-fast);
}
.sidebar-toggle:hover { background: var(--accent); color: #000; border-color: var(--accent); }

/* ── Main content area ───────────────────────────────────── */
.main {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    min-width: 0;
}

/* ── Topbar ──────────────────────────────────────────────── */
.topbar {
    height: var(--header-h);
    background: var(--bg-alt);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--sp-5);
    flex-shrink: 0;
    gap: var(--sp-4);
}
.topbar-title {
    font-size: var(--text-md);
    font-weight: 600;
    color: var(--text);
    flex: 1;
}
.topbar-actions {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
}

/* ── Page content ────────────────────────────────────────── */
.page {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: var(--sp-5);
    display: flex;
    flex-direction: column;
    gap: var(--sp-5);
}

/* ── Page header ─────────────────────────────────────────── */
.page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--sp-4);
    flex-shrink: 0;
}
.page-title {
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.02em;
}
.page-sub {
    font-size: var(--text-sm);
    color: var(--text-muted);
    margin-top: 2px;
}

/* ── KPI row ─────────────────────────────────────────────── */
.kpi-row {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: var(--sp-4);
    flex-shrink: 0;
}

/* ── Split panel ─────────────────────────────────────────── */
.split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--sp-4);
    flex: 1;
    min-height: 0;
}
.split-panel {
    display: flex;
    flex-direction: column;
    min-height: 0;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--r-xl);
    overflow: hidden;
}
.split-panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--sp-3) var(--sp-4);
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    gap: var(--sp-2);
    background: var(--bg-alt);
}
.split-panel-title {
    font-size: var(--text-xs);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    flex-shrink: 0;
}
.split-panel-body {
    flex: 1;
    overflow: auto;
}

/* ── Auth / public pages ─────────────────────────────────── */
.auth-page {
    min-height: 100vh;
    background: var(--bg);
    display: flex;
    align-items: stretch;
}
.auth-left {
    flex: 1;
    background: var(--bg-alt);
    border-right: 1px solid var(--border);
    padding: var(--sp-12);
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: var(--sp-5);
}
.auth-right {
    flex: 0 0 400px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--sp-10) var(--sp-8);
}
.auth-form {
    width: 100%;
    max-width: 340px;
    display: flex;
    flex-direction: column;
    gap: var(--sp-4);
}
.auth-logo {
    display: flex;
    align-items: center;
    gap: var(--sp-3);
    margin-bottom: var(--sp-2);
}
.auth-headline {
    font-size: var(--text-4xl);
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.2;
}
.auth-headline span { color: var(--accent); }
.auth-desc {
    font-size: var(--text-md);
    color: var(--text-muted);
    line-height: 1.6;
    max-width: 480px;
}
.auth-feature {
    display: flex;
    align-items: center;
    gap: var(--sp-3);
    font-size: var(--text-sm);
    color: var(--text-muted);
}
.auth-feature-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent);
    flex-shrink: 0;
}

/* Form submit area */
.form-submit {
    display: flex;
    flex-direction: column;
    gap: var(--sp-2);
    margin-top: var(--sp-2);
}
.form-error {
    background: rgba(255,107,107,0.1);
    border: 1px solid rgba(255,107,107,0.3);
    border-radius: var(--r-md);
    padding: var(--sp-2) var(--sp-3);
    font-size: var(--text-sm);
    color: var(--danger);
}

/* ── Theme toggle ────────────────────────────────────────── */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: var(--r-md);
    border: 1px solid var(--border);
    background: var(--surface);
    cursor: pointer;
    color: var(--text-muted);
    font-size: 14px;
    transition: all var(--t-fast);
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); }

/* ── Section divider ─────────────────────────────────────── */
.divider {
    height: 1px;
    background: var(--border);
    margin: var(--sp-4) 0;
}

/* ── Mobile menu button (hamburger) ──────────────────────── */
.mobile-menu-btn {
    display: none;
    position: fixed;
    top: 7px;
    left: 10px;
    z-index: 201;
    width: 34px;
    height: 34px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--r-md);
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text);
    font-size: 16px;
    flex-shrink: 0;
    transition: background var(--t-fast), border-color var(--t-fast);
}
.mobile-menu-btn:hover { background: var(--bg-alt); border-color: var(--accent); }

/* Sidebar backdrop (mobile overlay) */
.sidebar-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.55);
    z-index: 199;
}
.sidebar-backdrop.visible { display: block; }

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 900px) {
    /* Sidebar becomes a slide-in drawer */
    .sidebar {
        position: fixed;
        top: 0;
        left: -280px;
        height: 100%;
        width: 260px !important;
        min-width: 260px !important;
        z-index: 200;
        transition: left 0.22s ease, box-shadow 0.22s ease;
        box-shadow: none;
    }
    .sidebar.mobile-open {
        left: 0;
        box-shadow: 8px 0 32px rgba(0, 0, 0, 0.45);
    }
    .sidebar-toggle  { display: none; }
    .sidebar-resizer { display: none; }
    .mobile-menu-btn { display: flex; }
    .topbar { padding-left: 52px; }

    .split     { grid-template-columns: 1fr; }
    .auth-left { display: none; }
    .auth-right { flex: 1; }
    .kpi-row   { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 600px) {
    .page    { padding: var(--sp-3); }
    .kpi-row { grid-template-columns: 1fr; }
    .topbar  { padding-left: 52px; padding-right: var(--sp-3); }
}