public/style.css

body {
    font-family: "Microsoft YaHei", sans-serif;
    margin: 0;
    padding: 0;
    background-image: url("background.png");
    background-size: cover;
}

.container {
    display: flex;
    flex-direction: column;
    margin: auto;
    max-width: 1184px;
    padding: 20px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
}

.heading {
    color: #444;
    font-size: 1.5em;
    margin-bottom: 2px;
}

.button-container {
    display: flex;
    justify-content: flex-end;
    flex-wrap: wrap;
}

.button {
    margin-left: 10px;
    padding: 5px 10px;
    border: none;
    border-radius: 5px;
    background-color: #007BFF;
    color: white;
    cursor: pointer;
    transition: background-color 0.3s;
}

.button:hover {
    background-color: #0056b3;
}

.button[disabled] {
    background-color: gray;
}

.messages {
    display: flex;
    flex-direction: column;
    border: 1px solid #ccc;
    padding: 10px;
    margin-bottom: 20px;
    border-radius: 5px;
}

.textarea {
    width: 100%;
    margin-bottom: 10px;
    border: 1px solid #ccc;
    border-radius: 5px;
    padding: 10px;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", sans-serif;
}

.selector {
    margin-bottom: 10px;
}

.message {
    margin-bottom: 10px;
    padding: 10px;
    border-radius: 12px;
    box-shadow: 0 0.3px 0.9px rgba(0, 0, 0, 0.12), 0 1.6px 3.6px rgba(0, 0, 0, 0.16);
    font-size: 16px;
    width: fit-content;
    max-width: 768px;
    position: relative;
}

.user-message {
    color: white;
    background-image: linear-gradient(90deg, #904887 10.79%, #8B257E 87.08%);
    align-self: flex-end;
}

.assistant-message {
    background-color: rgba(255, 255, 255, 0.6);
}

.other-message {
    background-color: rgba(255, 255, 255, 0.3);
    align-self: flex-end;
}

.message * {
    margin-block: 0;
}

.add-button, .delete-button, .edit-button {
    box-shadow: 0 0.3px 0.9px rgba(0, 0, 0, 0.12), 0 1.6px 3.6px rgba(0, 0, 0, 0.16);
    position: absolute;
    top: -36px;
    background-color: white;
    color: white;
    border: none;
    border-radius: 8px;
    width: 36px;
    height: 36px;
    text-align: center;
    line-height: 36px;
    cursor: pointer;
}

.delete-button {
    right: 0;
}

.edit-button {
    right: 36px;
}

.add-button {
    right: 72px;
}

.add-button:hover, .delete-button:hover, .edit-button:hover {
    background-color: rgb(255, 255, 255, 0.06);
}