Mailspring/internal_packages/print/static/print-styles.css

body {
  overflow: auto !important;
}
#message-list {
  background: transparent;
}
#print-button {
  float:right;
  margin-left: 10px;

  /* From main button styles: */
  padding: 0 0.8em;
  border-radius: 3px;
  display: inline-block;
  height: 1.9em;
  line-height: 1.9em;
  font-size: 13.02px;
  cursor: default;
  color: #231f20;
  position: relative;
  color: #ffffff;
  font-weight: 500;
  background: linear-gradient(to bottom, #6bb1f9 0%, #0a80ff 100%);
  box-shadow: none;
  border: 1px solid #3878fa;
}
#print-header {
  padding: 15px 20px 0 20px;
}
#print-header img {
  zoom: 0.5;
}
#print-header .logo-wrapper {
  display: flex;
  align-items: center;
  font-family: "Nylas-Pro", "Helvetica", "Lucidia Grande", sans-serif !important;
}
#print-header h1 {
  font-size: 1.5em !important;
  font-family: "Nylas-Pro", "Helvetica", "Lucidia Grande", sans-serif !important;
}
#print-header .account {
  margin-left: auto;
  font-size: 0.8em !important;
}
#print-header .participant {
  font-size: 0.7em;
  font-family: "Nylas-Pro", "Helvetica", "Lucidia Grande", sans-serif !important;
}

/* Elements to hide */
.message-subject-wrap {
  display: none !important;
}
.minified-bundle,.headers,.scrollbar-track,.message-icons-wrap,.header-toggle-control {
  display: none !important;
}
.message-actions-wrap {
  display: none;
}
.collapsed.message-item-wrap,.draft.message-item-wrap {
  display: none !important;
}
.message-item-area>div {
  display: none !important;
}
.quoted-text-control, .footer-reply-area-wrap {
  display: none;
}

@media only print {
  body,#message-list,.message-item-wrap,.message-item-white-wrap,
  .message-item-area,.inbox-html-wrapper {
    display: block !important;
    width: auto !important;
    height: auto !important;
    overflow: visible !important;
  }
  #message-list {
    min-height: initial;
  }
  #print-header {
    padding: 0;
  }
  #print-header .account {
    font-size: 0.7em;
  }
  .message-item-wrap {
    display: block;
  }
  .message-item-area>span {
    page-break-before: avoid;
  }
  .message-item-area>header {
    page-break-after: avoid;
  }
}