body {
    font-family: "Roboto", sans-serif;
    background: #f6f6f6;
    font-weight: 400;
}
.header {
  background: #b80000;
  width: 100%;
  z-index: 100;
  position: relative;
}
.header a {
  text-decoration: none;
}


header .logo-doan {
    width: 100%;
    max-width: 60px;
}

header h1 {
  font-size: 20px;
  margin-top: 5px;
  line-height: 30px;
}
.preview-section {
    border: 2px dashed #ccc;
    padding: 20px;
    background-color: #f9f9f9;
    text-align: center;
}
.preview-container {
    position: relative;
    display: inline-block;
    max-width: 100%;
}
.preview-image {
    max-width: 100%;
    height: auto;
}
.preview-text {
    position: absolute;
    top: 72%;
    left: 46%;
    right: 10%;
    color: #004aad;
    font-size: 12px;
    text-align: left;
    max-width: 300px;
    word-wrap: break-word;
    white-space: pre-wrap;
    line-height: 1.3;
    z-index: 3;
    font-family: "Anton", sans-serif;
}
.preview-signature {
    position: absolute;
    bottom: 14%;
    left: 10%;
    color: #00bf63;
    font-size: 11px;
    text-align: left;
    max-width: 300px;
    white-space: pre-wrap;
    line-height: 1.3;
    z-index: 3;
    font-weight: bold;
    font-family: "Anton", sans-serif;
}
.preview-avatar {
  position: absolute;
  border-radius: 50%;
  object-fit: cover;
  z-index: 1;
}
@media (max-width: 768px) {
    .preview-text, .preview-signature {
        font-size: 8px;
    }
}