@layer layout {
  .app-shell { min-height: 100vh; }

  .sidebar {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 40;
    width: var(--sidebar-width);
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
    padding: var(--space-6) var(--space-4) var(--space-4);
    background: var(--color-nav-bg);
    color: var(--color-nav-text);
    border-right: 1px solid var(--color-border);
    overflow-y: auto;
  }

  .brand {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-1);
    text-decoration: none;
  }
  .brand__logo { display: block; width: 200px; height: auto; }
  .brand__tagline { padding-left: var(--space-2); font-size: var(--fs-xs); font-weight: var(--fw-medium); color: var(--color-nav-text); }
  .brand--plate { align-self: flex-start; padding: var(--space-3) var(--space-4); border-radius: var(--radius-lg); background: var(--color-logo-plate); box-shadow: var(--shadow-2); }
  .brand--plate .brand__logo { width: 200px; }

  .nav { display: flex; flex-direction: column; gap: var(--space-1); }
  .nav__group-label {
    margin: var(--space-4) var(--space-3) var(--space-2);
    font-size: var(--fs-xs);
    font-weight: var(--fw-semibold);
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-nav-text);
  }
  .nav__item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    min-height: var(--tap-min);
    width: 100%;
    padding: var(--space-2) var(--space-3);
    border: 0;
    border-radius: var(--radius-pill);
    background: transparent;
    color: var(--color-nav-text);
    font-size: var(--fs-md);
    font-weight: var(--fw-medium);
    text-align: left;
    text-decoration: none;
  }
  .nav__item:hover { background: var(--color-nav-hover); color: var(--color-nav-text-strong); }
  .nav__item[aria-current="page"] { background: var(--color-nav-active); color: var(--color-on-nav-active); font-weight: var(--fw-semibold); box-shadow: var(--shadow-primary); }

  .sidebar__footer { margin-top: auto; display: flex; flex-direction: column; gap: var(--space-3); }
  .account {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding-top: var(--space-4);
    border-top: 1px solid var(--color-border);
  }
  .account__info { flex: 1; min-width: 0; }
  .account__avatar {
    display: grid;
    place-items: center;
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--color-nav-active);
    color: var(--color-on-nav-active);
    font-weight: var(--fw-bold);
  }
  .account__name { display: block; overflow: hidden; color: var(--color-nav-text-strong); font-size: var(--fs-sm); font-weight: var(--fw-semibold); text-overflow: ellipsis; white-space: nowrap; }
  .account__role { display: block; font-size: var(--fs-xs); }
  .account__actions { display: flex; flex-direction: column; gap: var(--space-1); }
  .account__action {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    width: 100%;
    min-height: 40px;
    padding: var(--space-2) var(--space-3);
    border: 0;
    border-radius: var(--radius-pill);
    background: transparent;
    color: var(--color-nav-text);
    font-size: var(--fs-sm);
    font-weight: var(--fw-medium);
    text-align: left;
  }
  .account__action:hover { background: var(--color-nav-hover); color: var(--color-nav-text-strong); }
  .account__action > span { display: inline-flex; }

  .workspace { margin-left: var(--sidebar-width); min-height: 100vh; display: flex; flex-direction: column; }

  .topbar {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    min-height: 56px;
    padding: var(--space-2) var(--space-8) 0;
  }
  .topbar__actions { margin-left: auto; display: flex; align-items: center; gap: var(--space-2); }

  main { flex: 1; width: 100%; max-width: var(--content-max); margin: 0 auto; padding: var(--space-8); }
  main:focus { outline: none; }

  .sidebar-backdrop { display: none; }

  .page-header { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: var(--space-4); margin-bottom: var(--space-6); }
  .page-header__eyebrow { display: block; margin-bottom: var(--space-1); font-size: var(--fs-sm); font-weight: var(--fw-semibold); letter-spacing: 0.04em; text-transform: uppercase; color: var(--color-accent-text); }
  .page-header__subtitle { margin-top: var(--space-2); color: var(--color-text-muted); max-width: 60ch; }
  .page-header__actions { display: flex; flex-wrap: wrap; gap: var(--space-2); }

  .grid { display: grid; gap: var(--space-6); }
  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .grid--sidebar { grid-template-columns: minmax(0, 2fr) minmax(280px, 1fr); }
  .stack { display: flex; flex-direction: column; gap: var(--space-4); }
  .cluster { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-2); }
  .cluster--end { align-items: flex-end; }
  .page-section { margin-bottom: var(--space-6); }

  .login-screen { min-height: 100vh; display: grid; grid-template-columns: 1fr 1fr; }
  .login-story {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: var(--space-8);
    position: relative;
    overflow: hidden;
    padding: var(--space-10);
    background: var(--color-hero-bg);
    color: var(--color-on-hero);
  }
  .login-story > * { position: relative; }
  .login-story::before,
  .login-story::after { content: ""; position: absolute; border-radius: 50%; border: 56px solid var(--color-hero-ring); pointer-events: none; }
  .login-story::before { width: 420px; height: 420px; right: -160px; bottom: -140px; }
  .login-story::after { width: 180px; height: 180px; left: -70px; top: 38%; border-width: 32px; border-color: var(--color-hero-ring-dark); }
  .login-story h1 { font-size: var(--fs-3xl); color: var(--color-on-hero); margin: var(--space-4) 0; letter-spacing: -0.03em; }
  .login-story p { font-size: var(--fs-lg); max-width: 42ch; }
  .login-panel { display: grid; place-items: center; padding: var(--space-8); }
  .login-panel__inner { width: min(420px, 100%); display: flex; flex-direction: column; gap: var(--space-4); }
  .login-panel h2 { font-size: var(--fs-2xl); }
  .demo-accounts { padding: var(--space-4); border-radius: var(--radius-md); background: var(--color-surface); box-shadow: var(--shadow-1); }
  .demo-accounts__title { font-size: var(--fs-sm); font-weight: var(--fw-semibold); margin-bottom: var(--space-2); }

  .startup { position: fixed; inset: 0; display: grid; place-content: center; justify-items: center; gap: var(--space-3); background: var(--color-bg); color: var(--color-text-muted); }
  .startup img { width: 220px; height: auto; }

  @media (max-width: 1100px) {
    .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .grid--sidebar { grid-template-columns: minmax(0, 1fr); }
  }

  @media (max-width: 900px) {
    .sidebar { transform: translateX(-100%); transition: transform 0.2s ease; box-shadow: var(--shadow-2); }
    .sidebar.is-open { transform: none; }
    .sidebar-backdrop.is-visible { display: block; position: fixed; inset: 0; z-index: 35; background: var(--color-overlay); }
    .workspace { margin-left: 0; }

    .topbar { padding: var(--space-2) var(--space-4); }
    main { padding: var(--space-6) var(--space-4); }
    .login-screen { grid-template-columns: 1fr; }
    .login-story { padding: var(--space-6); }
    .login-story h1 { font-size: var(--fs-2xl); }
  }

  @media (max-width: 640px) {
    .grid--2, .grid--3 { grid-template-columns: minmax(0, 1fr); }
    h1 { font-size: var(--fs-xl); }
    .page-header { align-items: stretch; }
    .page-header__actions { width: 100%; }
    .page-header__actions > * { flex: 1; }
  }
}