/* Shared application shell and permission-aware navigation. */
:root[data-sidebar-state="collapsed"] { --sidebar-current-width: var(--sidebar-collapsed-width); }

.sidebar[data-app-sidebar] {
    position: sticky;
    z-index: 12;
    top: 0;
    display: flex;
    width: var(--sidebar-current-width);
    min-width: var(--sidebar-current-width);
    height: 100vh;
    flex-direction: column;
    overflow: visible;
    padding: 20px 14px 16px;
    border-right: 1px solid var(--sidebar-border);
    background: var(--sidebar);
    color: var(--sidebar-text);
    box-shadow: var(--sidebar-shadow);
    transition: width .2s ease, min-width .2s ease, padding .2s ease, transform .2s ease;
}

.sidebar[data-app-sidebar]:empty::before {
    display: grid;
    min-height: 100%;
    place-items: center;
    color: var(--sidebar-muted);
    content: "Загрузка меню…";
    font-size: 12px;
}

.sidebar-header { display: flex; min-height: 40px; align-items: center; gap: 8px; }
.app-brand { display: flex; min-width: 0; flex: 1; align-items: center; gap: 10px; padding: 0 6px; color: var(--sidebar-brand-text); font-family: var(--font-display); font-size: 18px; font-weight: 720; letter-spacing: -.02em; }
.brand-mark { display: grid; width: 34px; height: 34px; min-width: 34px; place-items: center; border-radius: 10px; background: var(--primary); color: var(--on-accent); }
.brand-icon-svg { width: 19px; height: 19px; }
.brand-label { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.sidebar-toggle,.mobile-nav-close { width: 36px; height: 36px; flex: 0 0 36px; color: var(--sidebar-muted); }
.sidebar-toggle:hover,.mobile-nav-close:hover { background: var(--sidebar-hover); color: var(--sidebar-text); }
.sidebar-toggle-icon { width: 18px; height: 18px; }
.mobile-nav-close { display: none; }

.app-navigation { flex: 1; min-height: 0; margin-top: 26px; overflow-x: hidden; overflow-y: auto; scrollbar-width: thin; scrollbar-color: var(--sidebar-border) transparent; }
.nav-groups { display: grid; gap: 22px; }
.nav-group { min-width: 0; }
.nav-section-title { margin: 0 10px 7px; color: var(--sidebar-muted); font-size: 10px; font-weight: 720; letter-spacing: .12em; line-height: 1.4; }
.nav-list { display: grid; gap: 3px; margin: 0; padding: 0; list-style: none; }
.nav-link { position: relative; display: flex; min-height: 42px; align-items: center; gap: 11px; padding: 9px 11px; border-radius: var(--radius-md); color: var(--sidebar-text); font-size: 13px; font-weight: 600; transition: background-color .15s ease, color .15s ease; }
.nav-link:hover { background: var(--sidebar-hover); color: var(--sidebar-brand-text); }
.nav-link.active { background: var(--sidebar-active); color: var(--primary); }
.nav-link.active::before { position: absolute; top: 11px; bottom: 11px; left: -14px; width: 3px; border-radius: 0 3px 3px 0; background: var(--sidebar-active-border); content: ""; }
.nav-link:focus-visible,.logout-button:focus-visible { outline: 3px solid var(--focus); outline-offset: 1px; }
.nav-link svg,.nav-icon { width: 18px; height: 18px; min-width: 18px; }
.nav-link span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.sidebar-footer { flex: none; margin-top: 20px; color: var(--sidebar-text); }
.sidebar-footer .theme-field { margin: 12px 4px; }
.sidebar-footer .theme-field label { display: block; margin-bottom: 6px; color: var(--sidebar-muted); font-size: 11px; font-weight: 650; }
.sidebar-footer .select { width: 100%; min-height: 36px; border-color: var(--sidebar-border); background: var(--sidebar-soft); color: var(--sidebar-text); }
.sidebar-footer .user-card { display: flex; align-items: center; gap: 10px; padding: 14px 7px 4px; border-top: 1px solid var(--sidebar-border); }
.sidebar-footer .avatar { display: grid; width: 34px; height: 34px; flex: 0 0 34px; place-items: center; border: 0; border-radius: 50%; background: var(--primary-soft); color: var(--primary); font-weight: 750; }
.sidebar-footer .user-meta { min-width: 0; }
.sidebar-footer .user-name { overflow: hidden; font-weight: 650; text-overflow: ellipsis; white-space: nowrap; }
.sidebar-footer .user-role { color: var(--sidebar-muted); font-size: 11px; }
.logout-button { display: flex; width: 100%; min-height: 38px; align-items: center; gap: 10px; margin-top: 5px; padding: 8px; border: 0; border-radius: var(--radius-md); background: transparent; color: var(--sidebar-text); cursor: pointer; }
.logout-button:hover { background: var(--sidebar-hover); color: var(--sidebar-brand-text); text-decoration: none; }
.logout-icon { width: 17px; height: 17px; }
.sidebar-load-error { display: grid; gap: 4px; margin: auto 7px; padding: 14px; border-radius: var(--radius-lg); background: var(--danger-soft); color: var(--danger); }
.sidebar-load-error span { font-size: 12px; }

:root[data-sidebar-state="collapsed"] .sidebar[data-app-sidebar] { padding-right: 10px; padding-left: 10px; }
:root[data-sidebar-state="collapsed"] .sidebar-header { display: grid; justify-items: center; }
:root[data-sidebar-state="collapsed"] .app-brand { width: 42px; flex: none; justify-content: center; padding: 0; }
:root[data-sidebar-state="collapsed"] .brand-label,
:root[data-sidebar-state="collapsed"] .nav-section-title,
:root[data-sidebar-state="collapsed"] .nav-link span,
:root[data-sidebar-state="collapsed"] .theme-field,
:root[data-sidebar-state="collapsed"] .user-meta,
:root[data-sidebar-state="collapsed"] .logout-button span { display: none; }
:root[data-sidebar-state="collapsed"] .app-navigation { width: 100%; margin-top: 18px; overflow: visible; }
:root[data-sidebar-state="collapsed"] .nav-groups { gap: 14px; }
:root[data-sidebar-state="collapsed"] .nav-link { justify-content: center; padding: 10px; }
:root[data-sidebar-state="collapsed"] .nav-link.active::before { top: 10px; bottom: 10px; left: -10px; }
:root[data-sidebar-state="collapsed"] .nav-link::after { position: absolute; z-index: 40; top: 50%; left: calc(100% + 10px); visibility: hidden; padding: 6px 9px; transform: translateY(-50%); border: 1px solid var(--tooltip-border); border-radius: var(--radius-sm); background: var(--tooltip-bg); color: var(--tooltip-text); box-shadow: var(--shadow-sm); content: attr(data-tooltip); font-size: 12px; font-weight: 600; opacity: 0; pointer-events: none; transition: opacity .12s ease, visibility .12s ease; }
:root[data-sidebar-state="collapsed"] .nav-link:hover::after,
:root[data-sidebar-state="collapsed"] .nav-link:focus-visible::after { visibility: visible; opacity: 1; }
:root[data-sidebar-state="collapsed"] .sidebar-footer .user-card { justify-content: center; padding: 12px 0 4px; }
:root[data-sidebar-state="collapsed"] .logout-button { justify-content: center; }

.mobile-menu-button { display: none; }
.mobile-nav-overlay { position: fixed; z-index: 40; inset: 0; visibility: hidden; border: 0; background: var(--overlay); opacity: 0; cursor: default; transition: opacity .2s ease, visibility .2s ease; }

.gradebook-page .app-shell { min-height: 100vh; }
.gradebook-page .gradebook-content { min-width: 0; }

@media (max-width:760px) {
    :root { --sidebar-current-width: var(--sidebar-width); }
    .app-shell,.student-shell { display: block; }
    .mobile-menu-button { display: grid; width: 44px; height: 44px; flex: 0 0 44px; }
    .mobile-menu-icon { width: 21px; height: 21px; }
    .sidebar[data-app-sidebar],
    :root[data-sidebar-state="collapsed"] .sidebar[data-app-sidebar] { position: fixed; z-index: 50; inset: 0 auto 0 0; display: flex; width: min(86vw, 320px); min-width: min(86vw, 320px); height: 100dvh; padding: 18px 14px 16px; transform: translateX(-102%); border-right: 1px solid var(--sidebar-border); box-shadow: var(--shadow-lg); }
    :root[data-mobile-nav="open"] .sidebar[data-app-sidebar] { transform: translateX(0); }
    :root[data-mobile-nav="open"] .mobile-nav-overlay { visibility: visible; opacity: 1; }
    .sidebar-header,:root[data-sidebar-state="collapsed"] .sidebar-header { display: flex; }
    .app-brand,:root[data-sidebar-state="collapsed"] .app-brand { width: auto; flex: 1; justify-content: flex-start; padding: 0 6px; }
    :root[data-sidebar-state="collapsed"] .brand-label,
    :root[data-sidebar-state="collapsed"] .nav-section-title,
    :root[data-sidebar-state="collapsed"] .nav-link span,
    :root[data-sidebar-state="collapsed"] .theme-field,
    :root[data-sidebar-state="collapsed"] .user-meta,
    :root[data-sidebar-state="collapsed"] .logout-button span { display: initial; }
    .sidebar-toggle { display: none; }
    .mobile-nav-close { display: grid; }
    .app-navigation,:root[data-sidebar-state="collapsed"] .app-navigation { width: auto; margin-top: 24px; overflow-x: hidden; overflow-y: auto; }
    .nav-groups,:root[data-sidebar-state="collapsed"] .nav-groups { display: grid; width: auto; gap: 20px; }
    .nav-group { display: block; }
    .nav-section-title { display: block; }
    .nav-list { display: grid; }
    .nav-list li { width: auto; }
    .nav-link,:root[data-sidebar-state="collapsed"] .nav-link { min-height: 44px; flex-direction: row; justify-content: flex-start; gap: 11px; padding: 10px 11px; font-size: 14px; text-align: left; }
    .nav-link.active::before,:root[data-sidebar-state="collapsed"] .nav-link.active::before { top: 11px; bottom: 11px; left: -14px; }
    :root[data-sidebar-state="collapsed"] .nav-link::after { display: none; }
    .sidebar-footer .user-card,:root[data-sidebar-state="collapsed"] .sidebar-footer .user-card { justify-content: flex-start; padding: 14px 7px 4px; }
    .logout-button,:root[data-sidebar-state="collapsed"] .logout-button { justify-content: flex-start; }
    body.mobile-nav-open { overflow: hidden; }
}

@media (prefers-reduced-motion: reduce) {
    .app-shell,.sidebar[data-app-sidebar],.mobile-nav-overlay { transition-duration: .01ms !important; }
}