body {
    font-family: 'Courier New', Courier, monospace;
    background-color: #000;
    color: #0F0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px 10px;
    box-sizing: border-box;
}

.container {
    width: min(90vw, 900px);
    border: 2px solid #0F0;
    background-color: #000;
    box-shadow: 5px 5px 0 #0F0;
    margin: 0 auto;
}

header {
    background-color: #0F0;
    color: #000;
    padding: 10px;
    text-align: center;
    border-bottom: 2px solid #0F0;
}

h1 {
    margin: 0;
    font-size: 1.5em;
    text-transform: uppercase;
}

.chat-box {
    max-height: calc(100vh - 260px);
    min-height: 250px;
    overflow-y: scroll;
    padding: 10px;
    border-bottom: 2px solid #0F0;
}

.chat-message {
    margin-bottom: 10px;
    line-height: 1.4;
}

.chat-message strong {
    color: #0F0;
}

#chat-form {
    display: flex;
    gap: 10px;
    padding: 10px;
    box-sizing: border-box;
}

#user-input {
    flex-grow: 1;
    background-color: #000;
    color: #0F0;
    border: 2px solid #0F0;
    padding: 10px;
    font-family: 'Courier New', Courier, monospace;
}

#user-input:focus {
    outline: none;
}

button {
    background-color: #0F0;
    color: #000;
    border: 2px solid #0F0;
    padding: 10px 20px;
    cursor: pointer;
    font-family: 'Courier New', Courier, monospace;
    text-transform: uppercase;
}

@media (max-width: 600px) {
    body {
        padding: 10px;
    }

    .container {
        width: 100%;
        box-shadow: 0 0 0;
    }

    #chat-form {
        flex-direction: column;
        gap: 8px;
    }

    button {
        width: 100%;
    }

    .chat-box {
        max-height: calc(100vh - 320px);
    }
}