body { min-height: 100vh; display: flex; flex-direction: column;
       align-items: center; justify-content: center; }
.auth-card { width: 100%; max-width: 420px; }
.editor-preview-main { width: 100%; min-height: 100vh; }
.theme-toggle { cursor: pointer; border: none; background: transparent;
        font-size: 1rem; padding: .3rem .5rem; border-radius: .4rem; color: inherit; }
.theme-toggle:hover { background: var(--bs-secondary-bg, #f8f9fa); }