* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: Tahoma, Arial, sans-serif;
}

body {
    background-color: #1e1e1e;
    color: #ffffff;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.chat-container {
    width: 100%;
    max-width: 600px;
    background-color: #252526;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.5);
    display: flex;
    flex-direction: column;
    height: 90vh;
}

header {
    background-color: #333333;
    padding: 15px;
    text-align: center;
    border-top-right-radius: 10px;
    border-top-left-radius: 10px;
    border-bottom: 2px solid #007acc;
}

header h1 {
    font-size: 1.2rem;
    color: #4fc1ff;
}

header p {
    font-size: 0.9rem;
    color: #cccccc;
    margin-top: 5px;
}

.model-selector {
    padding: 10px 15px;
    background-color: #2d2d2d;
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 0.9rem;
}

select {
    padding: 5px;
    border-radius: 5px;
    background-color: #1e1e1e;
    color: white;
    border: 1px solid #444;
    outline: none;
    cursor: pointer;
}

.chat-box {
    flex: 1;
    padding: 15px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.message {
    padding: 10px 15px;
    border-radius: 8px;
    max-width: 80%;
    line-height: 1.5;
    font-size: 0.95rem;
}

.ai-message {
    background-color: #333333;
    align-self: flex-start;
    border-bottom-right-radius: 0;
}

.user-message {
    background-color: #007acc;
    align-self: flex-end;
    border-bottom-left-radius: 0;
}

.input-area {
    display: flex;
    padding: 15px;
    background-color: #2d2d2d;
    border-bottom-right-radius: 10px;
    border-bottom-left-radius: 10px;
    gap: 10px;
}

#user-input {
    flex: 1;
    padding: 10px;
    border-radius: 5px;
    border: none;
    outline: none;
    background-color: #1e1e1e;
    color: white;
}

#send-btn {
    padding: 10px 20px;
    background-color: #007acc;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
}

#send-btn:hover {
    background-color: #005999;
}