@vaadin/vaadin-lumo-styles/src/mixins/overlay.css

Lumo is a design system foundation for modern web applications, used by Vaadin components

/**
 * @license
 * Copyright (c) 2017 - 2026 Vaadin Ltd.
 * This program is available under Apache License Version 2.0, available at https://vaadin.com/license/
 */
@media lumo_mixins_overlay {
  :host {
    z-index: 200;
    position: fixed;

    /* Despite of what the names say, <vaadin-overlay> is just a container
        for position/sizing/alignment. The actual overlay is the overlay part. */

    /* Use flexbox alignment for the overlay part. */
    display: flex;
    flex-direction: column; /* makes dropdowns sizing easier */
    /* Align to center by default. */
    align-items: center;
    justify-content: center;

    /* Override native [popover] user agent styles */
    width: auto;
    height: auto;
    border: none;
    padding: 0;
    background-color: transparent;
    overflow: visible;

    /* Allow centering when max-width/max-height applies. */
    margin: auto;

    /* The host is not clickable, only the overlay part is. */
    pointer-events: none;

    /* Remove tap highlight on touch devices. */
    -webkit-tap-highlight-color: transparent;

    /* CSS API for host */
    --vaadin-overlay-viewport-bottom: 0px;

    inset: var(--vaadin-overlay-viewport-inset, var(--lumo-space-m));
    /* Workaround for Edge issue (only on Surface), where an overflowing vaadin-list-box inside vaadin-select-overlay makes the overlay transparent */
    /* stylelint-disable-next-line */
    outline: 0px solid transparent;
  }

  :host([hidden]),
  :host(:not([opened]):not([closing])),
  :host(:not([opened]):not([closing])) [part='overlay'] {
    display: none !important;
  }

  [part='overlay'] {
    overflow: auto;
    pointer-events: auto;

    /* Prevent overflowing the host */
    max-width: 100%;
    box-sizing: border-box;

    -webkit-tap-highlight-color: initial; /* reenable tap highlight inside */
    background-color: var(--lumo-base-color);
    background-image: linear-gradient(var(--lumo-tint-5pct), var(--lumo-tint-5pct));
    border-radius: var(--lumo-border-radius-m);
    box-shadow:
      0 0 0 1px var(--lumo-shade-5pct),
      var(--lumo-box-shadow-m);

    /* CSS reset for font styles */
    color: var(--lumo-body-text-color);
    font-family: var(--lumo-font-family);
    font-size: var(--lumo-font-size-m);
    font-style: normal;
    font-weight: 400;
    font-variant: normal;
    line-height: var(--lumo-line-height-m);
    letter-spacing: 0;
    text-align: initial;
    text-decoration: none;
    text-indent: initial;
    text-transform: none;
    user-select: text;
    white-space: initial;
    word-spacing: initial;
    -webkit-text-size-adjust: 100%;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }

  [part='backdrop'] {
    z-index: -1;
    content: '';
    background: rgba(0, 0, 0, 0.5);
    position: fixed;
    inset: 0;
    pointer-events: auto;
    background-color: var(--lumo-shade-20pct);
    animation: 0.2s lumo-overlay-backdrop-enter both;
    will-change: opacity;
  }

  [part='content'] {
    padding: var(--lumo-space-xs);
  }

  @keyframes lumo-overlay-backdrop-enter {
    0% {
      opacity: 0;
    }
  }

  :host([closing]) [part='backdrop'] {
    animation: 0.2s lumo-overlay-backdrop-exit both;
  }

  @keyframes lumo-overlay-backdrop-exit {
    100% {
      opacity: 0;
    }
  }

  @keyframes lumo-overlay-dummy-animation {
    0% {
      opacity: 1;
    }

    100% {
      opacity: 1;
    }
  }
}