#mail-install-button {
    display: block;
    margin: 12px auto 0;
    min-height: 44px;
    border: 0;
    padding: 10px 16px;
    background: transparent;
    color: #0f6cbd;
    font: 400 14px/1.4 system-ui, sans-serif;
    text-decoration: underline;
    text-underline-offset: 3px;
    cursor: pointer;
}
#mail-install-button:hover { color: #0c508b; }
#mail-install-button[hidden] { display: none !important; }
#mail-install-dialog {
    box-sizing: border-box;
    width: min(440px, calc(100vw - 32px));
    max-height: calc(100dvh - 40px);
    margin: auto;
    padding: 24px;
    border: 0;
    border-radius: 16px;
    background: #fff;
    color: #17212b;
    font: 16px/1.5 system-ui, sans-serif;
}
#mail-install-dialog::backdrop { background: #0009; }
#mail-install-dialog h2 { font-size: 22px; margin: 0 0 16px; }
#mail-install-dialog p { margin: 12px 0; }
#mail-install-dialog button { padding: 10px 20px; cursor: pointer; }
#mail-install-button:focus-visible, #mail-install-dialog button:focus-visible {
    outline: 3px solid #edaa35;
    outline-offset: 3px;
}