* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: "MS Sans Serif", "Segoe UI", Tahoma, sans-serif;
    background-color: #008080; /* Classic Teal */
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0;
}

.chat-container {
    width: 100%;
    max-width: 600px;
    height: 90vh;
    background-color: #c0c0c0;
    border: 2px solid;
    border-color: #ffffff #808080 #808080 #ffffff;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    box-shadow: 2px 2px 10px rgba(0, 0, 0, 0.5);
}

header {
    padding: 4px 6px;
    background: linear-gradient(90deg, #000080, #1084d0);
    color: #fff;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: bold;
}

header h1 {
    font-size: 14px;
    margin: 0;
}

.model-selector {
    margin-left: 15px;
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 11px;
    color: #fff;
}

.model-selector select {
    background-color: #c0c0c0;
    border: 2px solid;
    border-color: #808080 #ffffff #ffffff #808080;
    font-family: inherit;
    font-size: 11px;
    padding: 1px;
    outline: none;
}

.login-btn {
    background-color: #c0c0c0;
    border: 2px solid;
    border-color: #ffffff #808080 #808080 #ffffff;
    color: #000000;
    padding: 1px 6px;
    font-family: inherit;
    font-size: 11px;
    cursor: pointer;
    outline: none;
}

.login-btn:active {
    border-color: #808080 #ffffff #ffffff #808080;
}

.back-link {
    color: #fff;
    text-decoration: none;
    font-size: 11px;
    background: #c0c0c0;
    color: #000;
    padding: 1px 6px;
    border: 2px solid;
    border-color: #ffffff #808080 #808080 #ffffff;
}

.back-link:hover {
    text-decoration: none;
    background: #d0d0d0;
}

.chat-messages {
    flex: 1;
    padding: 10px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 8px;
    background: #ffffff;
    margin: 4px;
    border: 2px solid;
    border-color: #808080 #ffffff #ffffff #808080;
}

.message {
    max-width: 90%;
    padding: 6px 10px;
    font-size: 12px;
    line-height: 1.4;
    border: 1px solid #808080;
}

.message.user {
    align-self: flex-end;
    background-color: #e0e0e0;
    color: #000;
}

.message.ai {
    align-self: flex-start;
    background-color: #ffffff;
    color: #000;
}

.login-required-message {
    text-align: center;
    padding: 40px 20px;
    background: #ffffff;
    margin: 4px;
    border: 2px solid;
    border-color: #808080 #ffffff #ffffff #808080;
    flex: 1;
}

.chat-input {
    padding: 8px;
    display: flex;
    gap: 4px;
    background: #c0c0c0;
}

.chat-input input {
    flex: 1;
    padding: 4px;
    border: 2px solid;
    border-color: #808080 #ffffff #ffffff #808080;
    font-family: inherit;
    font-size: 12px;
    outline: none;
}

.chat-input button {
    background-color: #c0c0c0;
    border: 2px solid;
    border-color: #ffffff #808080 #808080 #ffffff;
    padding: 4px 12px;
    font-family: inherit;
    font-size: 12px;
    font-weight: bold;
    cursor: pointer;
    outline: none;
}

.chat-input button:active {
    border-color: #808080 #ffffff #ffffff #808080;
}

.chat-input button:disabled {
    color: #808080;
    cursor: not-allowed;
}
    background-color: #007bff;
    color: #fff;
    border: none;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 600;
}

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

.chat-input button:disabled {
    background-color: #ccc;
    cursor: not-allowed;
}