* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
    min-height: 100%;
    font-family: Arial, Helvetica, sans-serif;
    background: #f2f2f2;
    color: #222;
}

body {
    padding: 20px;
}

.page {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    background: #ffffff;
    border: 1px solid #cccccc;
}

.header {
    padding: 20px;
    border-bottom: 1px solid #dddddd;
    background: #eeeeee;
}

.logo {
    font-size: 24px;
    font-weight: bold;
}

.subtitle {
    margin-top: 5px;
    font-size: 14px;
    color: #666666;
}

.chat {
    min-height: 450px;
    padding: 20px;
    overflow-y: auto;
}

.message {
    margin-bottom: 15px;
    clear: both;
}

.message.assistant {
    text-align: left;
}

.message.user {
    text-align: right;
}

.bubble {
    display: inline-block;
    max-width: 85%;
    padding: 12px 15px;
    border-radius: 8px;
    line-height: 1.5;
    white-space: pre-wrap;
    word-wrap: break-word;
}

.assistant .bubble {
    background: #eeeeee;
}

.user .bubble {
    background: #dddddd;
}

.input-area {
    padding: 15px;
    border-top: 1px solid #dddddd;
}

textarea {
    display: block;
    width: 100%;
    min-height: 80px;
    padding: 12px;
    border: 1px solid #aaaaaa;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 16px;
    resize: vertical;
}

button {
    margin-top: 10px;
    padding: 12px 25px;
    border: 0;
    background: #222222;
    color: white;
    font-size: 16px;
    cursor: pointer;
}

button:hover {
    background: #444444;
}

button:disabled {
    background: #999999;
    cursor: default;
}

.footer {
    padding: 10px 15px;
    border-top: 1px solid #dddddd;
    color: #777777;
    font-size: 12px;
}